National Library of Energy BETA

Sample records for kilowatt-hour parallel generation

  1. NREL Finds Up to 6-cent per Kilowatt-Hour Extra Value with Concentrate...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the relative value of CSP. CSP could also allow greater penetration of PV by making the grid more flexible and reducing curtailment of PV by generating energy after the sun sets. ...

  2. Communication Graph Generator for Parallel Programs

    Energy Science and Technology Software Center (OSTI)

    2014-04-08

    Graphator is a collection of relatively simple sequential programs that generate communication graphs/matrices for commonly occurring patterns in parallel programs. Currently, there is support for five communication patterns: two-dimensional 4-point stencil, four-dimensional 8-point stencil, all-to-alls over sub-communicators, random near-neighbor communication, and near-neighbor communication.

  3. Massively parallel mesh generation for physics codes

    SciTech Connect (OSTI)

    Hardin, D.D.

    1996-06-01

    Massively parallel processors (MPPs) will soon enable realistic 3-D physical modeling of complex objects and systems. Work is planned or presently underway to port many of LLNL`s physical modeling codes to MPPs. LLNL`s DSI3D electromagnetics code already can solve 40+ million zone problems on the 256 processor Meiko. However, the author lacks the software necessary to generate and manipulate the large meshes needed to model many complicated 3-D geometries. State-of-the-art commercial mesh generators run on workstations and have a practical limit of several hundred thousand elements. In the foreseeable future MPPs will solve problems with a billion mesh elements. The objective of the Parallel Mesh Generation (PMESH) Project is to develop a unique mesh generation system that can construct large 3-D meshes (up to a billion elements) on MPPs. Such a capability will remove a critical roadblock to unleashing the power of MPPs for physical analysis and will put LLNL at the forefront of mesh generation technology. PMESH will ``front-end`` a variety of LLNL 3-D physics codes, including those in the areas of electromagnetics, structural mechanics, thermal analysis, and hydrodynamics. The DSI3D and DYNA3D codes are already running on MPPs. The primary goal of the PMESH project is to provide the robust generation of large meshes for complicated 3-D geometries through the appropriate distribution of the generation task between the user`s workstation and the MPP. Secondary goals are to support the unique features of LLNL physics codes (e.g., unusual elements) and to minimize the user effort required to generate different meshes for the same geometry. PMESH`s capabilities are essential because mesh generation is presently a major limiting factor in simulating larger and more complex 3-D geometries. PMESH will significantly enhance LLNL`s capabilities in physical simulation by advancing the state-of-the-art in large mesh generation by 2 to 3 orders of magnitude.

  4. SPRNG Scalable Parallel Random Number Generator LIbrary

    Energy Science and Technology Software Center (OSTI)

    2010-03-16

    This revision corrects some errors in SPRNG 1. Users of newer SPRNG versions can obtain the corrected files and build their version with it. This version also improves the scalability of some of the application-based tests in the SPRNG test suite. It also includes an interface to a parallel Mersenne Twister, so that if users install the Mersenne Twister, then they can test this generator with the SPRNG test suite and also use some SPRNGmore » features with that generator.« less

  5. Building the Next Generation of Parallel Applications: Co-Design...

    Office of Scientific and Technical Information (OSTI)

    Applications: Co-Design Opportunities and Challenges. Citation Details In-Document Search Title: Building the Next Generation of Parallel Applications: Co-Design Opportunities and ...

  6. Parallel paving: An algorithm for generating distributed, adaptive, all-quadrilateral meshes on parallel computers

    SciTech Connect (OSTI)

    Lober, R.R.; Tautges, T.J.; Vaughan, C.T.

    1997-03-01

    Paving is an automated mesh generation algorithm which produces all-quadrilateral elements. It can additionally generate these elements in varying sizes such that the resulting mesh adapts to a function distribution, such as an error function. While powerful, conventional paving is a very serial algorithm in its operation. Parallel paving is the extension of serial paving into parallel environments to perform the same meshing functions as conventional paving only on distributed, discretized models. This extension allows large, adaptive, parallel finite element simulations to take advantage of paving`s meshing capabilities for h-remap remeshing. A significantly modified version of the CUBIT mesh generation code has been developed to host the parallel paving algorithm and demonstrate its capabilities on both two dimensional and three dimensional surface geometries and compare the resulting parallel produced meshes to conventionally paved meshes for mesh quality and algorithm performance. Sandia`s {open_quotes}tiling{close_quotes} dynamic load balancing code has also been extended to work with the paving algorithm to retain parallel efficiency as subdomains undergo iterative mesh refinement.

  7. Generating unstructured nuclear reactor core meshes in parallel

    SciTech Connect (OSTI)

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor core examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.

  8. Generating unstructured nuclear reactor core meshes in parallel

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor coremore » examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.« less

  9. Asynchronous parallel generating set search for linearly-constrained optimization.

    SciTech Connect (OSTI)

    Lewis, Robert Michael; Griffin, Joshua D.; Kolda, Tamara Gibson

    2006-08-01

    Generating set search (GSS) is a family of direct search methods that encompasses generalized pattern search and related methods. We describe an algorithm for asynchronous linearly-constrained GSS, which has some complexities that make it different from both the asynchronous bound-constrained case as well as the synchronous linearly-constrained case. The algorithm has been implemented in the APPSPACK software framework and we present results from an extensive numerical study using CUTEr test problems. We discuss the results, both positive and negative, and conclude that GSS is a reliable method for solving small-to-medium sized linearly-constrained optimization problems without derivatives.

  10. Generation of quasi-monoenergetic carbon ions accelerated parallel to the plane of a sandwich target

    SciTech Connect (OSTI)

    Wang, J. W.; Murakami, M.; Weng, S. M.; Xu, H.; Ju, J. J.; Luan, S. X.; Yu, W.

    2014-12-15

    A new ion acceleration scheme, namely, target parallel Coulomb acceleration, is proposed in which a carbon plate sandwiched between gold layers is irradiated with intense linearly polarized laser pulses. The high electrostatic field generated by the gold ions efficiently accelerates the embedded carbon ions parallel to the plane of the target. The ion beam is found to be collimated by the concave-shaped Coulomb potential. As a result, a quasi-monoenergetic and collimated C{sup 6+}-ion beam with an energy exceeding 10 MeV/nucleon is produced at a laser intensity of 5 × 10{sup 19} W/cm{sup 2}.

  11. Bit error rate tester using fast parallel generation of linear recurring sequences

    DOE Patents [OSTI]

    Pierson, Lyndon G.; Witzke, Edward L.; Maestas, Joseph H.

    2003-05-06

    A fast method for generating linear recurring sequences by parallel linear recurring sequence generators (LRSGs) with a feedback circuit optimized to balance minimum propagation delay against maximal sequence period. Parallel generation of linear recurring sequences requires decimating the sequence (creating small contiguous sections of the sequence in each LRSG). A companion matrix form is selected depending on whether the LFSR is right-shifting or left-shifting. The companion matrix is completed by selecting a primitive irreducible polynomial with 1's most closely grouped in a corner of the companion matrix. A decimation matrix is created by raising the companion matrix to the (n*k).sup.th power, where k is the number of parallel LRSGs and n is the number of bits to be generated at a time by each LRSG. Companion matrices with 1's closely grouped in a corner will yield sparse decimation matrices. A feedback circuit comprised of XOR logic gates implements the decimation matrix in hardware. Sparse decimation matrices can be implemented with minimum number of XOR gates, and therefore a minimum propagation delay through the feedback circuit. The LRSG of the invention is particularly well suited to use as a bit error rate tester on high speed communication lines because it permits the receiver to synchronize to the transmitted pattern within 2n bits.

  12. Feasibility Study of Biomass Electrical Generation on Tribal Lands

    SciTech Connect (OSTI)

    Tom Roche; Richard Hartmann; Joohn Luton; Warren Hudelson; Roger Blomguist; Jan Hacker; Colene Frye

    2005-03-29

    The goals of the St. Croix Tribe are to develop economically viable energy production facilities using readily available renewable biomass fuel sources at an acceptable cost per kilowatt hour ($/kWh), to provide new and meaningful permanent employment, retain and expand existing employment (logging) and provide revenues for both producers and sellers of the finished product. This is a feasibility study including an assessment of available biomass fuel, technology assessment, site selection, economics viability given the foreseeable fuel and generation costs, as well as an assessment of the potential markets for renewable energy.

  13. Experimental and cost analyses of a one kilowatt-hour/day domestic refrigerator-freezer

    SciTech Connect (OSTI)

    Vineyard, E.A.; Sand, J.R.

    1997-05-01

    Over the past ten years, government regulations for energy standards, coupled with the utility industry`s promotion of energy-efficient appliances, have prompted appliance manufacturers to reduce energy consumption in refrigerator-freezers by approximately 40%. Global concerns over ozone depletion have also required the appliance industry to eliminate CFC-12 and CFC-11 while concurrently improving energy efficiency to reduce greenhouse emissions. In response to expected future regulations that will be more stringent, several design options were investigated for improving the energy efficiency of a conventionally designed, domestic refrigerator-freezer. The options, such as cabinet and door insulation improvements and a high-efficiency compressor were incorporated into a prototype refrigerator-freezer cabinet and refrigeration system. Baseline energy consumption of the original 1996 production refrigerator-freezer, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. The goal for the project was to achieve an energy consumption that is 50% below in 1993 National Appliance Energy Conservation Act (NAECA) standard for 20 ft{sup 3} (570 l) units. Based on discussions with manufacturers to determine the most promising energy-saving options, a laboratory prototype was fabricated and tested to experimentally verify the energy consumption of a unit with vacuum insulation around the freezer, increased door thicknesses, a high-efficiency compressor, a low wattage condenser fan, a larger counterflow evaporator, and adaptive defrost control.

  14. Fridge of the future: Designing a one-kilowatt-hour/day domestic refrigerator-freezer

    SciTech Connect (OSTI)

    Vineyard, E.A.; Sand, J.R.

    1998-03-01

    An industry/government Cooperative Research and Development Agreement (CRADA) was established to evaluate and test design concepts for a domestic refrigerator-freezer unit that represents approximately 60% of the US market. The goal of the CRADA was to demonstrate advanced technologies which reduce, by 50 percent, the 1993 NAECA standard energy consumption for a 20 ft{sup 3} (570 I) top-mount, automatic-defrost, refrigerator-freezer. For a unit this size, the goal translated to an energy consumption of 1.003 kWh/d. The general objective of the research was to facilitate the introduction of cost-efficient technologies by demonstrating design changes that can be effectively incorporated into new products. A 1996 model refrigerator-freezer was selected as the baseline unit for testing. Since the unit was required to meet the 1993 NAECA standards, the energy consumption was quite low (1.676 kWh/d), thus making further reductions in energy consumption very challenging. Among the energy saving features incorporated into the original design of the baseline unit were a low-wattage evaporator fan, increased insulation thicknesses, and liquid line flange heaters.

  15. Hydropower generation management under uncertainty via scenario analysis and parallel computation

    SciTech Connect (OSTI)

    Escudero, L.F.; Garcia, C.; Fuente, J.L. de la; Prieto, F.J.

    1996-05-01

    The authors present a modeling framework for the robust solution of hydroelectric power management problems with uncertainty in the values of the water inflows and outflows. A deterministic treatment of the problem provides unsatisfactory results, except for very short time horizons. The authors describe a model based on scenario analysis that allows a satisfactory treatment of uncertainty in the model data for medium and long-term planning problems. Their approach results in a huge model with a network submodel per scenario plus coupling constraints. The size of the problem and the structure of the constraints are adequate for the use of decomposition techniques and parallel computation tools. The authors present computational results for both sequential and parallel implementation versions of the codes, running on a cluster of workstations. The codes have been tested on data obtained from the reservoir network of Iberdrola, a power utility owning 50% of the total installed hydroelectric capacity of Spain, and generating 40% of the total energy demand.

  16. Hydropower generation management under uncertainty via scenario analysis and parallel computation

    SciTech Connect (OSTI)

    Escudero, L.F.; Garcia, C.; Fuente, J.L. de la; Prieto, F.J.

    1995-12-31

    The authors present a modeling framework for the robust solution of hydroelectric power management problems and uncertainty in the values of the water inflows and outflows. A deterministic treatment of the problem provides unsatisfactory results, except for very short time horizons. The authors describe a model based on scenario analysis that allows a satisfactory treatment of uncertainty in the model data for medium and long-term planning problems. This approach results in a huge model with a network submodel per scenario plus coupling constraints. The size of the problem and the structure of the constraints are adequate for the use of decomposition techniques and parallel computation tools. The authors present computational results for both sequential and parallel implementation versions of the codes, running on a cluster of workstations. The code have been tested on data obtained from the reservoir network of Iberdrola, a power utility owning 50% of the total installed hydroelectric capacity of Spain, and generating 40% of the total energy demand.

  17. Parallel Application Performance on Two Generations of Intel Xeon HPC Platforms

    SciTech Connect (OSTI)

    Chang, Christopher H.; Long, Hai; Sides, Scott; Vaidhynathan, Deepthi; Jones, Wesley

    2015-10-15

    Two next-generation node configurations hosting the Haswell microarchitecture were tested with a suite of microbenchmarks and application examples, and compared with a current Ivy Bridge production node on NREL" tm s Peregrine high-performance computing cluster. A primary conclusion from this study is that the additional cores are of little value to individual task performance--limitations to application parallelism, or resource contention among concurrently running but independent tasks, limits effective utilization of these added cores. Hyperthreading generally impacts throughput negatively, but can improve performance in the absence of detailed attention to runtime workflow configuration. The observations offer some guidance to procurement of future HPC systems at NREL. First, raw core count must be balanced with available resources, particularly memory bandwidth. Balance-of-system will determine value more than processor capability alone. Second, hyperthreading continues to be largely irrelevant to the workloads that are commonly seen, and were tested here, at NREL. Finally, perhaps the most impactful enhancement to productivity might occur through enabling multiple concurrent jobs per node. Given the right type and size of workload, more may be achieved by doing many slow things at once, than fast things in order.

  18. Parallel octree-based hexahedral mesh generation for eulerian to lagrangian conversion.

    SciTech Connect (OSTI)

    Staten, Matthew L.; Owen, Steven James

    2010-09-01

    Computational simulation must often be performed on domains where materials are represented as scalar quantities or volume fractions at cell centers of an octree-based grid. Common examples include bio-medical, geotechnical or shock physics calculations where interface boundaries are represented only as discrete statistical approximations. In this work, we introduce new methods for generating Lagrangian computational meshes from Eulerian-based data. We focus specifically on shock physics problems that are relevant to ASC codes such as CTH and Alegra. New procedures for generating all-hexahedral finite element meshes from volume fraction data are introduced. A new primal-contouring approach is introduced for defining a geometric domain. New methods for refinement, node smoothing, resolving non-manifold conditions and defining geometry are also introduced as well as an extension of the algorithm to handle tetrahedral meshes. We also describe new scalable MPI-based implementations of these procedures. We describe a new software module, Sculptor, which has been developed for use as an embedded component of CTH. We also describe its interface and its use within the mesh generation code, CUBIT. Several examples are shown to illustrate the capabilities of Sculptor.

  19. Property:PotentialHydropowerGeneration | Open Energy Information

    Open Energy Info (EERE)

    for a particular place. Use this type to express a quantity of energy. The default unit for energy on OpenEI is the Kilowatt hour (kWh), which is 3,600,000 Joules. http:...

  20. Property:PotentialOnshoreWindGeneration | Open Energy Information

    Open Energy Info (EERE)

    onshore wind in a place. Use this type to express a quantity of energy. The default unit for energy on OpenEI is the Kilowatt hour (kWh), which is 3,600,000 Joules. http:...

  1. Property:PotentialBiopowerSolidGeneration | Open Energy Information

    Open Energy Info (EERE)

    for a particular place. Use this type to express a quantity of energy. The default unit for energy on OpenEI is the Kilowatt hour (kWh), which is 3,600,000 Joules. http:...

  2. Localized parallel parametric generation of spin waves in a Ni{sub 81}Fe{sub 19} waveguide by spatial variation of the pumping field

    SciTech Connect (OSTI)

    Brächer, T.; Pirro, P.; Heussner, F.; Serga, A. A.; Hillebrands, B.

    2014-03-03

    We present the experimental observation of localized parallel parametric generation of spin waves in a transversally in-plane magnetized Ni{sub 81}Fe{sub 19} magnonic waveguide. The localization is realized by combining the threshold character of parametric generation with a spatially confined enhancement of the amplifying microwave field. The latter is achieved by modulating the width of the microstrip transmission line which is used to provide the pumping field. By employing microfocussed Brillouin light scattering spectroscopy, we analyze the spatial distribution of the generated spin waves and compare it with numerical calculations of the field distribution along the Ni{sub 81}Fe{sub 19} waveguide. This provides a local spin-wave excitation in transversally in-plane magnetized waveguides for a wide wave-vector range which is not restricted by the size of the generation area.

  3. EERE Success Story—Nevada: Geothermal Brine Brings Low-Cost Power with Big Potential

    Broader source: Energy.gov [DOE]

    Utilizing EERE funds, ElectraTherm developed a geothermal technology that will generate electricity for less than $0.06 per kilowatt hour.

  4. Nevada: Geothermal Brine Brings Low-Cost Power with Big Potential

    Broader source: Energy.gov [DOE]

    Utilizing EERE funds, ElectraTherm developed a geothermal technology that will generate electricity for less than $0.06 per kilowatt hour.

  5. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Recommended Reading & Resources Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead ...

  6. TRANSIMS Parallelization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TRANSIMS Parallelization This email address is being protected from spambots. You need JavaScript enabled to view it. - TRACC Director This email address is being protected from spambots. You need JavaScript enabled to view it. - Associate Computational Transportation Engineer Background TRANSIMS was originally developed by Los Alamos National Laboratory to run exclusively on a Linux cluster environment. In this initial version, the only parallelized component was the microsimulator. It worked

  7. Parallel Batch Scripts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel Batch Scripts Parallel Batch Scripts Parallel Environments on Genepool You can run parallel jobs that use MPI or OpenMP on Genepool as long as you make the appropriate changes to your submission script! To investigate the parallel environments that are available on Genepool, you can use Command Description qconf -sp <pename> Show the configuration for the specified parallel environment. qconf -spl Show a list of all currently configured parallel environments. Basic Parallel

  8. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Recommended Reading & Resources Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff Assistant Nickole Aguilar Garcia (505) 665-3048 Email Recommended Reading & References The Parallel Computing Summer Research Internship covers a broad range of topics that you may not have

  9. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    LaboratoryNational Security Education Center Menu About Seminar Series Summer Schools Workshops Viz Collab IS&T Projects NSEC » Information Science and Technology Institute (ISTI) » Summer School Programs » Parallel Computing Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff

  10. Special parallel processing workshop

    SciTech Connect (OSTI)

    1994-12-01

    This report contains viewgraphs from the Special Parallel Processing Workshop. These viewgraphs deal with topics such as parallel processing performance, message passing, queue structure, and other basic concept detailing with parallel processing.

  11. Parallel Python GDB

    Energy Science and Technology Software Center (OSTI)

    2012-08-05

    PGDB is a lightweight parallel debugger softrware product. It utilizes the open souce gdb debugger inside of a parallel python framework.

  12. Halfway There But Far From Done: SunShot Surges Ahead on Path...

    Office of Environmental Management (EM)

    the SunShot goals by the end of the decade, with ... kilowatt hours of solar electricity may be more valuable ... energy generation and consumption on the grid, will ...

  13. Net Metering

    Broader source: Energy.gov [DOE]

    Customer net excess generation (NEG) is carried forward at the utility's retail rate (i.e., as a kilowatt-hour credit) to a customer's next bill for up to 12 months. At the end of a 12-month...

  14. Net Metering

    Broader source: Energy.gov [DOE]

    Net excess generation (NEG) is treated as a kilowatt-hour (kWh) credit or other compensation on the customer's following bill.* At the beginning of the calendar year, a utility will purchase any...

  15. EERE Success Story-Nevada: Geothermal Brine Brings Low-Cost Power...

    Broader source: Energy.gov (indexed) [DOE]

    Utilizing a 1 million EERE investment, heat from geothermal fluids-a byproduct of gold mining-will be generating electricity this year for less than 0.06 per kilowatt hour with ...

  16. Tax Credits, Rebates & Savings | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Customer net excess generation (NEG) is carried forward at the utility's retail rate (i.e., as a kilowatt-hour credit) to a customer's next bill for up to 12 months. At the end of...

  17. Tax Credits, Rebates & Savings | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Metering Customer net excess generation (NEG) is carried forward at the utility's retail rate (i.e., as a kilowatt-hour credit) to a customer's next bill for up to 12 months. At...

  18. Tax Credits, Rebates & Savings | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Customer net excess generation (NEG) is carried forward at the utility's retail rate (i.e., as a kilowatt-hour credit) to a customer's next bill for up to 12 months. At the...

  19. Super Bowl of Energy: Solar Smashes Records | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Addthis MetLife Stadium, the site of yesterday's Super Bowl, features a ring of 1,350 solar panels that can generate 350,000 kilowatt hours of electricity annually. The number of ...

  20. Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation: Systematic Review and Harmonization

    SciTech Connect (OSTI)

    Whitaker, M.; Heath, G. A.; O'Donoughue, P.; Vorum, M.

    2012-04-01

    This systematic review and harmonization of life cycle assessments (LCAs) of utility-scale coal-fired electricity generation systems focuses on reducing variability and clarifying central tendencies in estimates of life cycle greenhouse gas (GHG) emissions. Screening 270 references for quality LCA methods, transparency, and completeness yielded 53 that reported 164 estimates of life cycle GHG emissions. These estimates for subcritical pulverized, integrated gasification combined cycle, fluidized bed, and supercritical pulverized coal combustion technologies vary from 675 to 1,689 grams CO{sub 2}-equivalent per kilowatt-hour (g CO{sub 2}-eq/kWh) (interquartile range [IQR]= 890-1,130 g CO{sub 2}-eq/kWh; median = 1,001) leading to confusion over reasonable estimates of life cycle GHG emissions from coal-fired electricity generation. By adjusting published estimates to common gross system boundaries and consistent values for key operational input parameters (most importantly, combustion carbon dioxide emission factor [CEF]), the meta-analytical process called harmonization clarifies the existing literature in ways useful for decision makers and analysts by significantly reducing the variability of estimates ({approx}53% in IQR magnitude) while maintaining a nearly constant central tendency ({approx}2.2% in median). Life cycle GHG emissions of a specific power plant depend on many factors and can differ from the generic estimates generated by the harmonization approach, but the tightness of distribution of harmonized estimates across several key coal combustion technologies implies, for some purposes, first-order estimates of life cycle GHG emissions could be based on knowledge of the technology type, coal mine emissions, thermal efficiency, and CEF alone without requiring full LCAs. Areas where new research is necessary to ensure accuracy are also discussed.

  1. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  2. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  3. Applications of Parallel Computers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computers Applications of Parallel Computers UCB CS267 Spring 2015 Tuesday & Thursday, 9:30-11:00 Pacific Time Applications of Parallel Computers, CS267, is a graduate-level course...

  4. PISTON (Portable Data Parallel Visualization and Analysis)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in a data-parallel way. By using nVidia's freely downloadable Thrust library and our own tools, we can generate executable codes for different acceleration hardware architectures...

  5. Parallel Atomistic Simulations

    SciTech Connect (OSTI)

    HEFFELFINGER,GRANT S.

    2000-01-18

    Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed.

  6. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mentors Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff Assistant Nickole Aguilar Garcia (505) 665-3048 Email 2016: Mentors Bob Robey Bob Robey XCP-2: EULERIAN CODES Bob Robey is a Research Scientist in the Eulerian Applications group at Los Alamos National Laboratory. He is the

  7. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Students Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff Assistant Nickole Aguilar Garcia (505) 665-3048 Email 2016: Students Peter Ahrens Peter Ahrens Electrical Engineering & Computer Science BS UC Berkeley Jenniffer Estrada Jenniffer Estrada Computer Science MS Youngstown

  8. Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Guide to Los Alamos Parallel Computing Summer Research Internship Creates next-generation leaders in HPC research and applications development Contacts Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff Assistant Nickole Aguilar Garcia (505) 665-3048 Email Guide to Los Alamos During your 10-week internship, we hope you have the opportunity to explore and enjoy Los Alamos and the surrounding area. Here are some

  9. Life Cycle Greenhouse Gas Emissions of Nuclear Electricity Generation: Systematic Review and Harmonization

    SciTech Connect (OSTI)

    Warner, E. S.; Heath, G. A.

    2012-04-01

    A systematic review and harmonization of life cycle assessment (LCA) literature of nuclear electricity generation technologies was performed to determine causes of and, where possible, reduce variability in estimates of life cycle greenhouse gas (GHG) emissions to clarify the state of knowledge and inform decision making. LCA literature indicates that life cycle GHG emissions from nuclear power are a fraction of traditional fossil sources, but the conditions and assumptions under which nuclear power are deployed can have a significant impact on the magnitude of life cycle GHG emissions relative to renewable technologies. Screening 274 references yielded 27 that reported 99 independent estimates of life cycle GHG emissions from light water reactors (LWRs). The published median, interquartile range (IQR), and range for the pool of LWR life cycle GHG emission estimates were 13, 23, and 220 grams of carbon dioxide equivalent per kilowatt-hour (g CO{sub 2}-eq/kWh), respectively. After harmonizing methods to use consistent gross system boundaries and values for several important system parameters, the same statistics were 12, 17, and 110 g CO{sub 2}-eq/kWh, respectively. Harmonization (especially of performance characteristics) clarifies the estimation of central tendency and variability. To explain the remaining variability, several additional, highly influential consequential factors were examined using other methods. These factors included the primary source energy mix, uranium ore grade, and the selected LCA method. For example, a scenario analysis of future global nuclear development examined the effects of a decreasing global uranium market-average ore grade on life cycle GHG emissions. Depending on conditions, median life cycle GHG emissions could be 9 to 110 g CO{sub 2}-eq/kWh by 2050.

  10. Parallel integrated thermal management

    DOE Patents [OSTI]

    Bennion, Kevin; Thornton, Matthew

    2014-08-19

    Embodiments discussed herein are directed to managing the heat content of two vehicle subsystems through a single coolant loop having parallel branches for each subsystem.

  11. Optimize Parallel Pumping Systems

    Broader source: Energy.gov [DOE]

    This tip sheet describes how to optimize the performance of multiple pumps operating continuously as part of a parallel pumping system.

  12. Eclipse Parallel Tools Platform

    Energy Science and Technology Software Center (OSTI)

    2005-02-18

    Designing and developing parallel programs is an inherently complex task. Developers must choose from the many parallel architectures and programming paradigms that are available, and face a plethora of tools that are required to execute, debug, and analyze parallel programs i these environments. Few, if any, of these tools provide any degree of integration, or indeed any commonality in their user interfaces at all. This further complicates the parallel developer's task, hampering software engineering practices,more » and ultimately reducing productivity. One consequence of this complexity is that best practice in parallel application development has not advanced to the same degree as more traditional programming methodologies. The result is that there is currently no open-source, industry-strength platform that provides a highly integrated environment specifically designed for parallel application development. Eclipse is a universal tool-hosting platform that is designed to providing a robust, full-featured, commercial-quality, industry platform for the development of highly integrated tools. It provides a wide range of core services for tool integration that allow tool producers to concentrate on their tool technology rather than on platform specific issues. The Eclipse Integrated Development Environment is an open-source project that is supported by over 70 organizations, including IBM, Intel and HP. The Eclipse Parallel Tools Platform (PTP) plug-in extends the Eclipse framwork by providing support for a rich set of parallel programming languages and paradigms, and a core infrastructure for the integration of a wide variety of parallel tools. The first version of the PTP is a prototype that only provides minimal functionality for parallel tool integration of a wide variety of parallel tools. The first version of the PTP is a prototype that only provides minimal functionality for parallel tool integration, support for a small number of parallel architectures

  13. Parallel computing works

    SciTech Connect (OSTI)

    Not Available

    1991-10-23

    An account of the Caltech Concurrent Computation Program (C{sup 3}P), a five year project that focused on answering the question: Can parallel computers be used to do large-scale scientific computations '' As the title indicates, the question is answered in the affirmative, by implementing numerous scientific applications on real parallel computers and doing computations that produced new scientific results. In the process of doing so, C{sup 3}P helped design and build several new computers, designed and implemented basic system software, developed algorithms for frequently used mathematical computations on massively parallel machines, devised performance models and measured the performance of many computers, and created a high performance computing facility based exclusively on parallel computers. While the initial focus of C{sup 3}P was the hypercube architecture developed by C. Seitz, many of the methods developed and lessons learned have been applied successfully on other massively parallel architectures.

  14. Parallel programming with PCN

    SciTech Connect (OSTI)

    Foster, I.; Tuecke, S.

    1991-12-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and C that allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. In includes both tutorial and reference material. It also presents the basic concepts that underly PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous FTP from Argonne National Laboratory in the directory pub/pcn at info.mcs.anl.gov (c.f. Appendix A).

  15. UPC (Unified Parallel C)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    UPC (Unified Parallel C) Description Unified Parallel C is a partitioned global address space (PGAS) language and an extension of the C programming language. Availability UPC is available on Edison and Hopper via both the Cray compilers, as well as through Berkeley UPC, a portable high-performance UPC compiler and runtime implementation. Using UPC To compile a UPC source file using the Cray compilers, you must first swap the Cray compiler with the default compiler. On Hopper: % module swap

  16. Parallel phase model : a programming model for high-end parallel machines with manycores.

    SciTech Connect (OSTI)

    Wu, Junfeng; Wen, Zhaofang; Heroux, Michael Allen; Brightwell, Ronald Brian

    2009-04-01

    This paper presents a parallel programming model, Parallel Phase Model (PPM), for next-generation high-end parallel machines based on a distributed memory architecture consisting of a networked cluster of nodes with a large number of cores on each node. PPM has a unified high-level programming abstraction that facilitates the design and implementation of parallel algorithms to exploit both the parallelism of the many cores and the parallelism at the cluster level. The programming abstraction will be suitable for expressing both fine-grained and coarse-grained parallelism. It includes a few high-level parallel programming language constructs that can be added as an extension to an existing (sequential or parallel) programming language such as C; and the implementation of PPM also includes a light-weight runtime library that runs on top of an existing network communication software layer (e.g. MPI). Design philosophy of PPM and details of the programming abstraction are also presented. Several unstructured applications that inherently require high-volume random fine-grained data accesses have been implemented in PPM with very promising results.

  17. Parallel time integration software

    Energy Science and Technology Software Center (OSTI)

    2014-07-01

    This package implements an optimal-scaling multigrid solver for the (non) linear systems that arise from the discretization of problems with evolutionary behavior. Typically, solution algorithms for evolution equations are based on a time-marching approach, solving sequentially for one time step after the other. Parallelism in these traditional time-integrarion techniques is limited to spatial parallelism. However, current trends in computer architectures are leading twards system with more, but not faster. processors. Therefore, faster compute speeds mustmore » come from greater parallelism. One approach to achieve parallelism in time is with multigrid, but extending classical multigrid methods for elliptic poerators to this setting is a significant achievement. In this software, we implement a non-intrusive, optimal-scaling time-parallel method based on multigrid reduction techniques. The examples in the package demonstrate optimality of our multigrid-reduction-in-time algorithm (MGRIT) for solving a variety of parabolic equations in two and three sparial dimensions. These examples can also be used to show that MGRIT can achieve significant speedup in comparison to sequential time marching on modern architectures.« less

  18. Parallel optical sampler

    DOE Patents [OSTI]

    Tauke-Pedretti, Anna; Skogen, Erik J; Vawter, Gregory A

    2014-05-20

    An optical sampler includes a first and second 1.times.n optical beam splitters splitting an input optical sampling signal and an optical analog input signal into n parallel channels, respectively, a plurality of optical delay elements providing n parallel delayed input optical sampling signals, n photodiodes converting the n parallel optical analog input signals into n respective electrical output signals, and n optical modulators modulating the input optical sampling signal or the optical analog input signal by the respective electrical output signals, and providing n successive optical samples of the optical analog input signal. A plurality of output photodiodes and eADCs convert the n successive optical samples to n successive digital samples. The optical modulator may be a photodiode interconnected Mach-Zehnder Modulator. A method of sampling the optical analog input signal is disclosed.

  19. Parallel programming with Ada

    SciTech Connect (OSTI)

    Kok, J.

    1988-01-01

    To the human programmer the ease of coding distributed computing is highly dependent on the suitability of the employed programming language. But with a particular language it is also important whether the possibilities of one or more parallel architectures can efficiently be addressed by available language constructs. In this paper the possibilities are discussed of the high-level language Ada and in particular of its tasking concept as a descriptional tool for the design and implementation of numerical and other algorithms that allow execution of parts in parallel. Language tools are explained and their use for common applications is shown. Conclusions are drawn about the usefulness of several Ada concepts.

  20. Parallel programming with PCN

    SciTech Connect (OSTI)

    Foster, I.; Tuecke, S.

    1993-01-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and Cthat allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. It includes both tutorial and reference material. It also presents the basic concepts that underlie PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous ftp from Argonne National Laboratory in the directory pub/pcn at info.mcs. ani.gov (cf. Appendix A). This version of this document describes PCN version 2.0, a major revision of the PCN programming system. It supersedes earlier versions of this report.

  1. Parallel Dislocation Simulator

    Energy Science and Technology Software Center (OSTI)

    2006-10-30

    ParaDiS is software capable of simulating the motion, evolution, and interaction of dislocation networks in single crystals using massively parallel computer architectures. The software is capable of outputting the stress-strain response of a single crystal whose plastic deformation is controlled by the dislocation processes.

  2. Parallel Multigrid Equation Solver

    Energy Science and Technology Software Center (OSTI)

    2001-09-07

    Prometheus is a fully parallel multigrid equation solver for matrices that arise in unstructured grid finite element applications. It includes a geometric and an algebraic multigrid method and has solved problems of up to 76 mullion degrees of feedom, problems in linear elasticity on the ASCI blue pacific and ASCI red machines.

  3. Parallel Total Energy

    Energy Science and Technology Software Center (OSTI)

    2004-10-21

    This is a total energy electronic structure code using Local Density Approximation (LDA) of the density funtional theory. It uses the plane wave as the wave function basis set. It can sue both the norm conserving pseudopotentials and the ultra soft pseudopotentials. It can relax the atomic positions according to the total energy. It is a parallel code using MP1.

  4. Parallel grid population

    DOE Patents [OSTI]

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  5. Ultrascalable petaflop parallel supercomputer

    DOE Patents [OSTI]

    Blumrich, Matthias A.; Chen, Dong; Chiu, George; Cipolla, Thomas M.; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E.; Hall, Shawn; Haring, Rudolf A.; Heidelberger, Philip; Kopcsay, Gerard V.; Ohmacht, Martin; Salapura, Valentina; Sugavanam, Krishnan; Takken, Todd

    2010-07-20

    A massively parallel supercomputer of petaOPS-scale includes node architectures based upon System-On-a-Chip technology, where each processing node comprises a single Application Specific Integrated Circuit (ASIC) having up to four processing elements. The ASIC nodes are interconnected by multiple independent networks that optimally maximize the throughput of packet communications between nodes with minimal latency. The multiple networks may include three high-speed networks for parallel algorithm message passing including a Torus, collective network, and a Global Asynchronous network that provides global barrier and notification functions. These multiple independent networks may be collaboratively or independently utilized according to the needs or phases of an algorithm for optimizing algorithm processing performance. The use of a DMA engine is provided to facilitate message passing among the nodes without the expenditure of processing resources at the node.

  6. Hybrid Optimization Parallel Search PACKage

    Energy Science and Technology Software Center (OSTI)

    2009-11-10

    HOPSPACK is open source software for solving optimization problems without derivatives. Application problems may have a fully nonlinear objective function, bound constraints, and linear and nonlinear constraints. Problem variables may be continuous, integer-valued, or a mixture of both. The software provides a framework that supports any derivative-free type of solver algorithm. Through the framework, solvers request parallel function evaluation, which may use MPI (multiple machines) or multithreading (multiple processors/cores on one machine). The framework providesmore » a Cache and Pending Cache of saved evaluations that reduces execution time and facilitates restarts. Solvers can dynamically create other algorithms to solve subproblems, a useful technique for handling multiple start points and integer-valued variables. HOPSPACK ships with the Generating Set Search (GSS) algorithm, developed at Sandia as part of the APPSPACK open source software project.« less

  7. Exploiting Network Parallelism

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exploiting Network Parallelism for Improving Data Transfer Performance Dan Gunter ∗ , Raj Kettimuthu † , Ezra Kissel ‡ , Martin Swany ‡ , Jun Yi § , Jason Zurawski ¶ ∗ Advanced Computing for Science Department, Lawrence Berkeley National Laboratory, Berkeley, CA † Mathematics and Computer Science Division, Argonne National Laboratory Argonne, IL ‡ School of Informatics and Computing, Indiana University, Bloomington, IN § Computation Institute, University of Chicago/Argonne

  8. Xyce parallel electronic simulator.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  9. Hybrid Parallel Programming with MPI and Unified Parallel C | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility Parallel Programming with MPI and Unified Parallel C Authors: Dinan, J., Balaji, P., Lusk, E., Sadayappan, P., Thakur, R. The Message Passing Interface (MPI) is one of the most widely used programming models for parallel computing. However, the amount of memory available to an MPI process is limited by the amount of local memory within a compute node. Partitioned Global Address Space (PGAS) models such as Unified Parallel C (UPC) are growing in popularity

  10. Parallel Harness for Informatic Stream Hashing

    Energy Science and Technology Software Center (OSTI)

    2012-09-11

    PHISH is a lightweight framework which a set of independent processes can use to exchange data as they run on the same desktop machine, on processors of a parallel machine, or on different machines across a network. This enables them to work in a coordinated parallel fashion to perform computations on either streaming, archived, or self-generated data. The PHISH distribution includes a simple, portable library for performing data exchanges in useful patterns either via MPImore » message-passing or ZMQ sockets. PHISH input scripts are used to describe a data-processing algorithm, and additional tools provided in the PHISH distribution convert the script into a form that can be launched as a parallel job.« less

  11. Applied Parallel Metadata Indexing

    SciTech Connect (OSTI)

    Jacobi, Michael R

    2012-08-01

    The GPFS Archive is parallel archive is a parallel archive used by hundreds of users in the Turquoise collaboration network. It houses 4+ petabytes of data in more than 170 million files. Currently, users must navigate the file system to retrieve their data, requiring them to remember file paths and names. A better solution might allow users to tag data with meaningful labels and searach the archive using standard and user-defined metadata, while maintaining security. last summer, I developed the backend to a tool that adheres to these design goals. The backend works by importing GPFS metadata into a MongoDB cluster, which is then indexed on each attribute. This summer, the author implemented security and developed the user interfae for the search tool. To meet security requirements, each database table is associated with a single user, which only stores records that the user may read, and requires a set of credentials to access. The interface to the search tool is implemented using FUSE (Filesystem in USErspace). FUSE is an intermediate layer that intercepts file system calls and allows the developer to redefine how those calls behave. In the case of this tool, FUSE interfaces with MongoDB to issue queries and populate output. A FUSE implementation is desirable because it allows users to interact with the search tool using commands they are already familiar with. These security and interface additions are essential for a usable product.

  12. Parallel ptychographic reconstruction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nashed, Youssef S. G.; Vine, David J.; Peterka, Tom; Deng, Junjing; Ross, Rob; Jacobsen, Chris

    2014-12-19

    Ptychography is an imaging method whereby a coherent beam is scanned across an object, and an image is obtained by iterative phasing of the set of diffraction patterns. It is able to be used to image extended objects at a resolution limited by scattering strength of the object and detector geometry, rather than at an optics-imposed limit. As technical advances allow larger fields to be imaged, computational challenges arise for reconstructing the correspondingly larger data volumes, yet at the same time there is also a need to deliver reconstructed images immediately so that one can evaluate the next steps tomoretake in an experiment. Here we present a parallel method for real-time ptychographic phase retrieval. It uses a hybrid parallel strategy to divide the computation between multiple graphics processing units (GPUs) and then employs novel techniques to merge sub-datasets into a single complex phase and amplitude image. Results are shown on a simulated specimen and a real dataset from an X-ray experiment conducted at a synchrotron light source.less

  13. Parallel ptychographic reconstruction

    SciTech Connect (OSTI)

    Nashed, Youssef S. G.; Vine, David J.; Peterka, Tom; Deng, Junjing; Ross, Rob; Jacobsen, Chris

    2014-12-19

    Ptychography is an imaging method whereby a coherent beam is scanned across an object, and an image is obtained by iterative phasing of the set of diffraction patterns. It is able to be used to image extended objects at a resolution limited by scattering strength of the object and detector geometry, rather than at an optics-imposed limit. As technical advances allow larger fields to be imaged, computational challenges arise for reconstructing the correspondingly larger data volumes, yet at the same time there is also a need to deliver reconstructed images immediately so that one can evaluate the next steps to take in an experiment. Here we present a parallel method for real-time ptychographic phase retrieval. It uses a hybrid parallel strategy to divide the computation between multiple graphics processing units (GPUs) and then employs novel techniques to merge sub-datasets into a single complex phase and amplitude image. Results are shown on a simulated specimen and a real dataset from an X-ray experiment conducted at a synchrotron light source.

  14. Unified Parallel Software

    Energy Science and Technology Software Center (OSTI)

    2003-12-01

    UPS (Unified Paralled Software is a collection of software tools libraries, scripts, executables) that assist in parallel programming. This consists of: o libups.a C/Fortran callable routines for message passing (utilities written on top of MPI) and file IO (utilities written on top of HDF). o libuserd-HDF.so EnSight user-defined reader for visualizing data files written with UPS File IO. o ups_libuserd_query, ups_libuserd_prep.pl, ups_libuserd_script.pl Executables/scripts to get information from data files and to simplify the use ofmore » EnSight on those data files. o ups_io_rm/ups_io_cp Manipulate data files written with UPS File IO These tools are portable to a wide variety of Unix platforms.« less

  15. Parallelization and automatic data distribution for nuclear reactor simulations

    SciTech Connect (OSTI)

    Liebrock, L.M.

    1997-07-01

    Detailed attempts at realistic nuclear reactor simulations currently take many times real time to execute on high performance workstations. Even the fastest sequential machine can not run these simulations fast enough to ensure that the best corrective measure is used during a nuclear accident to prevent a minor malfunction from becoming a major catastrophe. Since sequential computers have nearly reached the speed of light barrier, these simulations will have to be run in parallel to make significant improvements in speed. In physical reactor plants, parallelism abounds. Fluids flow, controls change, and reactions occur in parallel with only adjacent components directly affecting each other. These do not occur in the sequentialized manner, with global instantaneous effects, that is often used in simulators. Development of parallel algorithms that more closely approximate the real-world operation of a reactor may, in addition to speeding up the simulations, actually improve the accuracy and reliability of the predictions generated. Three types of parallel architecture (shared memory machines, distributed memory multicomputers, and distributed networks) are briefly reviewed as targets for parallelization of nuclear reactor simulation. Various parallelization models (loop-based model, shared memory model, functional model, data parallel model, and a combined functional and data parallel model) are discussed along with their advantages and disadvantages for nuclear reactor simulation. A variety of tools are introduced for each of the models. Emphasis is placed on the data parallel model as the primary focus for two-phase flow simulation. Tools to support data parallel programming for multiple component applications and special parallelization considerations are also discussed.

  16. Discontinuous Methods for Accurate, Massively Parallel Quantum...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Investigator for Discontinuous Methods for Accurate, Massively Parallel Quantum Molecular Dynamics. Discontinuous Methods for Accurate, Massively Parallel Quantum...

  17. Multilingual interfaces for parallel coupling in multiphysics and multiscale systems.

    SciTech Connect (OSTI)

    Ong, E. T.; Larson, J. W.; Norris, B.; Jacob, R. L.; Tobis, M.; Steder, M.; Mathematics and Computer Science; Univ. of Wisconsin; Australian National Univ.; Univ. of Chicago

    2007-01-01

    Multiphysics and multiscale simulation systems are emerging as a new grand challenge in computational science, largely because of increased computing power provided by the distributed-memory parallel programming model on commodity clusters. These systems often present a parallel coupling problem in their intercomponent data exchanges. Another potential problem in these coupled systems is language interoperability between their various constituent codes. In anticipation of combined parallel coupling/language interoperability challenges, we have created a set of interlanguage bindings for a successful parallel coupling library, the Model Coupling Toolkit. We describe the method used for automatically generating the bindings using the Babel language interoperability tool, and illustrate with short examples how MCT can be used from the C++ and Python languages. We report preliminary performance reports for the MCT interpolation benchmark. We conclude with a discussion of the significance of this work to the rapid prototyping of large parallel coupled systems.

  18. Parallel processing for control applications

    SciTech Connect (OSTI)

    Telford, J. W.

    2001-01-01

    Parallel processing has been a topic of discussion in computer science circles for decades. Using more than one single computer to control a process has many advantages that compensate for the additional cost. Initially multiple computers were used to attain higher speeds. A single cpu could not perform all of the operations necessary for real time operation. As technology progressed and cpu's became faster, the speed issue became less significant. The additional processing capabilities however continue to make high speeds an attractive element of parallel processing. Another reason for multiple processors is reliability. For the purpose of this discussion, reliability and robustness will be the focal paint. Most contemporary conceptions of parallel processing include visions of hundreds of single computers networked to provide 'computing power'. Indeed our own teraflop machines are built from large numbers of computers configured in a network (and thus limited by the network). There are many approaches to parallel configfirations and this presentation offers something slightly different from the contemporary networked model. In the world of embedded computers, which is a pervasive force in contemporary computer controls, there are many single chip computers available. If one backs away from the PC based parallel computing model and considers the possibilities of a parallel control device based on multiple single chip computers, a new area of possibilities becomes apparent. This study will look at the use of multiple single chip computers in a parallel configuration with emphasis placed on maximum reliability.

  19. Template based parallel checkpointing in a massively parallel computer system

    DOE Patents [OSTI]

    Archer, Charles Jens; Inglett, Todd Alan

    2009-01-13

    A method and apparatus for a template based parallel checkpoint save for a massively parallel super computer system using a parallel variation of the rsync protocol, and network broadcast. In preferred embodiments, the checkpoint data for each node is compared to a template checkpoint file that resides in the storage and that was previously produced. Embodiments herein greatly decrease the amount of data that must be transmitted and stored for faster checkpointing and increased efficiency of the computer system. Embodiments are directed to a parallel computer system with nodes arranged in a cluster with a high speed interconnect that can perform broadcast communication. The checkpoint contains a set of actual small data blocks with their corresponding checksums from all nodes in the system. The data blocks may be compressed using conventional non-lossy data compression algorithms to further reduce the overall checkpoint size.

  20. Small file aggregation in a parallel computing system

    DOE Patents [OSTI]

    Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Zhang, Jingwang

    2014-09-02

    Techniques are provided for small file aggregation in a parallel computing system. An exemplary method for storing a plurality of files generated by a plurality of processes in a parallel computing system comprises aggregating the plurality of files into a single aggregated file; and generating metadata for the single aggregated file. The metadata comprises an offset and a length of each of the plurality of files in the single aggregated file. The metadata can be used to unpack one or more of the files from the single aggregated file.

  1. Global synchronization of parallel processors using clock pulse width modulation

    SciTech Connect (OSTI)

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  2. Endpoint-based parallel data processing in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2014-08-12

    Endpoint-based parallel data processing in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI, including establishing a data communications geometry, the geometry specifying, for tasks representing processes of execution of the parallel application, a set of endpoints that are used in collective operations of the PAMI including a plurality of endpoints for one of the tasks; receiving in endpoints of the geometry an instruction for a collective operation; and executing the instruction for a collective operation through the endpoints in dependence upon the geometry, including dividing data communications operations among the plurality of endpoints for one of the tasks.

  3. Endpoint-based parallel data processing in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael E; Ratterman, Joseph D; Smith, Brian E

    2014-02-11

    Endpoint-based parallel data processing in a parallel active messaging interface ('PAMI') of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI, including establishing a data communications geometry, the geometry specifying, for tasks representing processes of execution of the parallel application, a set of endpoints that are used in collective operations of the PAMI including a plurality of endpoints for one of the tasks; receiving in endpoints of the geometry an instruction for a collective operation; and executing the instruction for a collective opeartion through the endpoints in dependence upon the geometry, including dividing data communications operations among the plurality of endpoints for one of the tasks.

  4. An integrated approach to improving the parallel applications development process

    SciTech Connect (OSTI)

    Rasmussen, Craig E; Watson, Gregory R; Tibbitts, Beth R

    2009-01-01

    The development of parallel applications is becoming increasingly important to a broad range of industries. Traditionally, parallel programming was a niche area that was primarily exploited by scientists trying to model extremely complicated physical phenomenon. It is becoming increasingly clear, however, that continued hardware performance improvements through clock scaling and feature-size reduction are simply not going to be achievable for much longer. The hardware vendor's approach to addressing this issue is to employ parallelism through multi-processor and multi-core technologies. While there is little doubt that this approach produces scaling improvements, there are still many significant hurdles to be overcome before parallelism can be employed as a general replacement to more traditional programming techniques. The Parallel Tools Platform (PTP) Project was created in 2005 in an attempt to provide developers with new tools aimed at addressing some of the parallel development issues. Since then, the introduction of a new generation of peta-scale and multi-core systems has highlighted the need for such a platform. In this paper, we describe some of the challenges facing parallel application developers, present the current state of PTP, and provide a simple case study that demonstrates how PTP can be used to locate a potential deadlock situation in an MPI code.

  5. An efficient parallel algorithm for matrix-vector multiplication

    SciTech Connect (OSTI)

    Hendrickson, B.; Leland, R.; Plimpton, S.

    1993-03-01

    The multiplication of a vector by a matrix is the kernel computation of many algorithms in scientific computation. A fast parallel algorithm for this calculation is therefore necessary if one is to make full use of the new generation of parallel supercomputers. This paper presents a high performance, parallel matrix-vector multiplication algorithm that is particularly well suited to hypercube multiprocessors. For an n x n matrix on p processors, the communication cost of this algorithm is O(n/[radical]p + log(p)), independent of the matrix sparsity pattern. The performance of the algorithm is demonstrated by employing it as the kernel in the well-known NAS conjugate gradient benchmark, where a run time of 6.09 seconds was observed. This is the best published performance on this benchmark achieved to date using a massively parallel supercomputer.

  6. Parallel Programming and Optimization for Intel Architecture

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel Programming and Optimization for Intel Architecture Parallel Programming and Optimization for Intel Architecture August 14, 2015 by Richard Gerber Intel is sponsoring a ...

  7. Computing contingency statistics in parallel.

    SciTech Connect (OSTI)

    Bennett, Janine Camille; Thompson, David; Pebay, Philippe Pierre

    2010-09-01

    Statistical analysis is typically used to reduce the dimensionality of and infer meaning from data. A key challenge of any statistical analysis package aimed at large-scale, distributed data is to address the orthogonal issues of parallel scalability and numerical stability. Many statistical techniques, e.g., descriptive statistics or principal component analysis, are based on moments and co-moments and, using robust online update formulas, can be computed in an embarrassingly parallel manner, amenable to a map-reduce style implementation. In this paper we focus on contingency tables, through which numerous derived statistics such as joint and marginal probability, point-wise mutual information, information entropy, and {chi}{sup 2} independence statistics can be directly obtained. However, contingency tables can become large as data size increases, requiring a correspondingly large amount of communication between processors. This potential increase in communication prevents optimal parallel speedup and is the main difference with moment-based statistics where the amount of inter-processor communication is independent of data size. Here we present the design trade-offs which we made to implement the computation of contingency tables in parallel.We also study the parallel speedup and scalability properties of our open source implementation. In particular, we observe optimal speed-up and scalability when the contingency statistics are used in their appropriate context, namely, when the data input is not quasi-diffuse.

  8. BAGEL: New-generation parallel quantum chemistry program | Argonne...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Event Sponsor: Mathematics and Computer Science Division Seminar Start Date: Apr 5 2016 - ... Shiozaki has been a recipient of Japan Society for the Promotion of Science Fellowship ...

  9. Designing a parallel simula machine

    SciTech Connect (OSTI)

    Papazoglou, M.P.; Georgiadis, P.I.; Maritsas, D.G.

    1983-10-01

    The parallel simula machine (PSM) architecture is based upon a master/slave topology, incorporating a master microprocessor. Interconnection circuitry between the master and slave processor modules uses a timesharing system bus and various programmable interrupt control units. Common and private memory modules reside in the PSM, and direct memory access transfers ease the master processor's workload. 5 references.

  10. Parallel, Distributed Scripting with Python

    SciTech Connect (OSTI)

    Miller, P J

    2002-05-24

    Parallel computers used to be, for the most part, one-of-a-kind systems which were extremely difficult to program portably. With SMP architectures, the advent of the POSIX thread API and OpenMP gave developers ways to portably exploit on-the-box shared memory parallelism. Since these architectures didn't scale cost-effectively, distributed memory clusters were developed. The associated MPI message passing libraries gave these systems a portable paradigm too. Having programmers effectively use this paradigm is a somewhat different question. Distributed data has to be explicitly transported via the messaging system in order for it to be useful. In high level languages, the MPI library gives access to data distribution routines in C, C++, and FORTRAN. But we need more than that. Many reasonable and common tasks are best done in (or as extensions to) scripting languages. Consider sysadm tools such as password crackers, file purgers, etc ... These are simple to write in a scripting language such as Python (an open source, portable, and freely available interpreter). But these tasks beg to be done in parallel. Consider the a password checker that checks an encrypted password against a 25,000 word dictionary. This can take around 10 seconds in Python (6 seconds in C). It is trivial to parallelize if you can distribute the information and co-ordinate the work.

  11. Parallelization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... that many intermediate calculations are done in place rather than saving values inmemory. ... many computer cores to leverage more computing power. 3 1.2 Magnetohydrodynamics A ...

  12. Cooperative storage of shared files in a parallel computing system with dynamic block size

    DOE Patents [OSTI]

    Bent, John M.; Faibish, Sorin; Grider, Gary

    2015-11-10

    Improved techniques are provided for parallel writing of data to a shared object in a parallel computing system. A method is provided for storing data generated by a plurality of parallel processes to a shared object in a parallel computing system. The method is performed by at least one of the processes and comprises: dynamically determining a block size for storing the data; exchanging a determined amount of the data with at least one additional process to achieve a block of the data having the dynamically determined block size; and writing the block of the data having the dynamically determined block size to a file system. The determined block size comprises, e.g., a total amount of the data to be stored divided by the number of parallel processes. The file system comprises, for example, a log structured virtual parallel file system, such as a Parallel Log-Structured File System (PLFS).

  13. Fuel cell generator

    DOE Patents [OSTI]

    Isenberg, Arnold O.

    1983-01-01

    High temperature solid oxide electrolyte fuel cell generators which allow controlled leakage among plural chambers in a sealed housing. Depleted oxidant and fuel are directly reacted in one chamber to combust remaining fuel and preheat incoming reactants. The cells are preferably electrically arranged in a series-parallel configuration.

  14. Compact Mesh Generator

    Energy Science and Technology Software Center (OSTI)

    2007-02-02

    The CMG is a small, lightweight, structured mesh generation code. It features a simple text input parser that allows setup of various meshes via a small set of text commands. Mesh generation data can be output to text, the silo file format, or the API can be directly queried by applications. It can run serially or in parallel via MPI. The CMG includes the ability to specify varius initial conditions on a mesh via meshmore » tags.« less

  15. Parallel multiplex laser feedback interferometry

    SciTech Connect (OSTI)

    Zhang, Song; Tan, Yidong; Zhang, Shulian

    2013-12-15

    We present a parallel multiplex laser feedback interferometer based on spatial multiplexing which avoids the signal crosstalk in the former feedback interferometer. The interferometer outputs two close parallel laser beams, whose frequencies are shifted by two acousto-optic modulators by 2Ω simultaneously. A static reference mirror is inserted into one of the optical paths as the reference optical path. The other beam impinges on the target as the measurement optical path. Phase variations of the two feedback laser beams are simultaneously measured through heterodyne demodulation with two different detectors. Their subtraction accurately reflects the target displacement. Under typical room conditions, experimental results show a resolution of 1.6 nm and accuracy of 7.8 nm within the range of 100 μm.

  16. Parallel Power Grid Simulation Toolkit

    Energy Science and Technology Software Center (OSTI)

    2015-09-14

    ParGrid is a 'wrapper' that integrates a coupled Power Grid Simulation toolkit consisting of a library to manage the synchronization and communication of independent simulations. The included library code in ParGid, named FSKIT, is intended to support the coupling multiple continuous and discrete even parallel simulations. The code is designed using modern object oriented C++ methods utilizing C++11 and current Boost libraries to ensure compatibility with multiple operating systems and environments.

  17. Scalable Parallel Algebraic Multigrid Solvers

    SciTech Connect (OSTI)

    Bank, R; Lu, S; Tong, C; Vassilevski, P

    2005-03-23

    The authors propose a parallel algebraic multilevel algorithm (AMG), which has the novel feature that the subproblem residing in each processor is defined over the entire partition domain, although the vast majority of unknowns for each subproblem are associated with the partition owned by the corresponding processor. This feature ensures that a global coarse description of the problem is contained within each of the subproblems. The advantages of this approach are that interprocessor communication is minimized in the solution process while an optimal order of convergence rate is preserved; and the speed of local subproblem solvers can be maximized using the best existing sequential algebraic solvers.

  18. Xyce parallel electronic simulator design.

    SciTech Connect (OSTI)

    Thornquist, Heidi K.; Rankin, Eric Lamont; Mei, Ting; Schiek, Richard Louis; Keiter, Eric Richard; Russo, Thomas V.

    2010-09-01

    This document is the Xyce Circuit Simulator developer guide. Xyce has been designed from the 'ground up' to be a SPICE-compatible, distributed memory parallel circuit simulator. While it is in many respects a research code, Xyce is intended to be a production simulator. As such, having software quality engineering (SQE) procedures in place to insure a high level of code quality and robustness are essential. Version control, issue tracking customer support, C++ style guildlines and the Xyce release process are all described. The Xyce Parallel Electronic Simulator has been under development at Sandia since 1999. Historically, Xyce has mostly been funded by ASC, the original focus of Xyce development has primarily been related to circuits for nuclear weapons. However, this has not been the only focus and it is expected that the project will diversify. Like many ASC projects, Xyce is a group development effort, which involves a number of researchers, engineers, scientists, mathmaticians and computer scientists. In addition to diversity of background, it is to be expected on long term projects for there to be a certain amount of staff turnover, as people move on to different projects. As a result, it is very important that the project maintain high software quality standards. The point of this document is to formally document a number of the software quality practices followed by the Xyce team in one place. Also, it is hoped that this document will be a good source of information for new developers.

  19. Efficient parallel global garbage collection on massively parallel computers

    SciTech Connect (OSTI)

    Kamada, Tomio; Matsuoka, Satoshi; Yonezawa, Akinori

    1994-12-31

    On distributed-memory high-performance MPPs where processors are interconnected by an asynchronous network, efficient Garbage Collection (GC) becomes difficult due to inter-node references and references within pending, unprocessed messages. The parallel global GC algorithm (1) takes advantage of reference locality, (2) efficiently traverses references over nodes, (3) admits minimum pause time of ongoing computations, and (4) has been shown to scale up to 1024 node MPPs. The algorithm employs a global weight counting scheme to substantially reduce message traffic. The two methods for confirming the arrival of pending messages are used: one counts numbers of messages and the other uses network `bulldozing.` Performance evaluation in actual implementations on a multicomputer with 32-1024 nodes, Fujitsu AP1000, reveals various favorable properties of the algorithm.

  20. Parallel computation with adaptive methods for elliptic and hyperbolic systems

    SciTech Connect (OSTI)

    Benantar, M.; Biswas, R.; Flaherty, J.E.; Shephard, M.S.

    1990-01-01

    We consider the solution of two dimensional vector systems of elliptic and hyperbolic partial differential equations on a shared memory parallel computer. For elliptic problems, the spatial domain is discretized using a finite quadtree mesh generation procedure and the differential system is discretized by a finite element-Galerkin technique with a piecewise linear polynomial basis. Resulting linear algebraic systems are solved using the conjugate gradient technique with element-by-element and symmetric successive over-relaxation preconditioners. Stiffness matrix assembly and linear system solutions are processed in parallel with computations scheduled on noncontiguous quadrants of the tree in order to minimize process synchronization. Determining noncontiguous regions by coloring the regular finite quadtree structure is far simpler than coloring elements of the unstructured mesh that the finite quadtree procedure generates. We describe linear-time complexity coloring procedures that use six and eight colors.

  1. Apply for the Parallel Computing Summer Research Internship

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How to Apply Apply for the Parallel Computing Summer Research Internship Creating next-generation leaders in HPC research and applications development Program Co-Lead Robert (Bob) Robey Email Program Co-Lead Gabriel Rockefeller Email Program Co-Lead Hai Ah Nam Email Professional Staff Assistant Nicole Aguilar Garcia (505) 665-3048 Email Current application deadline is February 5, 2016 with notification by early March 2016. Who can apply? Upper division undergraduate students and early graduate

  2. High voltage pulse generator

    DOE Patents [OSTI]

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  3. Information hiding in parallel programs

    SciTech Connect (OSTI)

    Foster, I.

    1992-01-30

    A fundamental principle in program design is to isolate difficult or changeable design decisions. Application of this principle to parallel programs requires identification of decisions that are difficult or subject to change, and the development of techniques for hiding these decisions. We experiment with three complex applications, and identify mapping, communication, and scheduling as areas in which decisions are particularly problematic. We develop computational abstractions that hide such decisions, and show that these abstractions can be used to develop elegant solutions to programming problems. In particular, they allow us to encode common structures, such as transforms, reductions, and meshes, as software cells and templates that can reused in different applications. An important characteristic of these structures is that they do not incorporate mapping, communication, or scheduling decisions: these aspects of the design are specified separately, when composing existing structures to form applications. This separation of concerns allows the same cells and templates to be reused in different contexts.

  4. Device for balancing parallel strings

    DOE Patents [OSTI]

    Mashikian, Matthew S.

    1985-01-01

    A battery plant is described which features magnetic circuit means in association with each of the battery strings in the battery plant for balancing the electrical current flow through the battery strings by equalizing the voltage across each of the battery strings. Each of the magnetic circuit means generally comprises means for sensing the electrical current flow through one of the battery strings, and a saturable reactor having a main winding connected electrically in series with the battery string, a bias winding connected to a source of alternating current and a control winding connected to a variable source of direct current controlled by the sensing means. Each of the battery strings is formed by a plurality of batteries connected electrically in series, and these battery strings are connected electrically in parallel across common bus conductors.

  5. Parallel computing in enterprise modeling.

    SciTech Connect (OSTI)

    Goldsby, Michael E.; Armstrong, Robert C.; Shneider, Max S.; Vanderveen, Keith; Ray, Jaideep; Heath, Zach; Allan, Benjamin A.

    2008-08-01

    This report presents the results of our efforts to apply high-performance computing to entity-based simulations with a multi-use plugin for parallel computing. We use the term 'Entity-based simulation' to describe a class of simulation which includes both discrete event simulation and agent based simulation. What simulations of this class share, and what differs from more traditional models, is that the result sought is emergent from a large number of contributing entities. Logistic, economic and social simulations are members of this class where things or people are organized or self-organize to produce a solution. Entity-based problems never have an a priori ergodic principle that will greatly simplify calculations. Because the results of entity-based simulations can only be realized at scale, scalable computing is de rigueur for large problems. Having said that, the absence of a spatial organizing principal makes the decomposition of the problem onto processors problematic. In addition, practitioners in this domain commonly use the Java programming language which presents its own problems in a high-performance setting. The plugin we have developed, called the Parallel Particle Data Model, overcomes both of these obstacles and is now being used by two Sandia frameworks: the Decision Analysis Center, and the Seldon social simulation facility. While the ability to engage U.S.-sized problems is now available to the Decision Analysis Center, this plugin is central to the success of Seldon. Because Seldon relies on computationally intensive cognitive sub-models, this work is necessary to achieve the scale necessary for realistic results. With the recent upheavals in the financial markets, and the inscrutability of terrorist activity, this simulation domain will likely need a capability with ever greater fidelity. High-performance computing will play an important part in enabling that greater fidelity.

  6. Graphical representation of parallel algorithmic processes. Master's thesis

    SciTech Connect (OSTI)

    Williams, E.M.

    1990-12-01

    Algorithm animation is a visualization method used to enhance understanding of functioning of an algorithm or program. Visualization is used for many purposes, including education, algorithm research, performance analysis, and program debugging. This research applies algorithm animation techniques to programs developed for parallel architectures, with specific on the Intel iPSC/2 hypercube. While both P-time and NP-time algorithms can potentially benefit from using visualization techniques, the set of NP-complete problems provides fertile ground for developing parallel applications, since the combinatoric nature of the problems makes finding the optimum solution impractical. The primary goals for this visualization system are: Data should be displayed as it is generated. The interface to the targe program should be transparent, allowing the animation of existing programs. Flexibility - the system should be able to animate any algorithm. The resulting system incorporates and extends two AFIT products: the AFIT Algorithm Animation Research Facility (AAARF) and the Parallel Resource Analysis Software Environment (PRASE). AAARF is an algorithm animation system developed primarily for sequential programs, but is easily adaptable for use with parallel programs. PRASE is an instrumentation package that extracts system performance data from programs on the Intel hypercubes. Since performance data is an essential part of analyzing any parallel program, views of the performance data are provided as an elementary part of the system. Custom software is designed to interface these systems and to display the program data. The program chosen as the example for this study is a member of the NP-complete problem set; it is a parallel implementation of a general.

  7. Parallel Programming and Optimization for Intel Architecture

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel Programming and Optimization for Intel Architecture Parallel Programming and Optimization for Intel Architecture August 14, 2015 by Richard Gerber Intel is sponsoring a series of webinars entitled "Parallel Programming and Optimization for Intel Architecture." Here's the schedule for August (Registration link is: https://attendee.gotowebinar.com/register/6325131222429932289) Mon, August 17 - "Hello world from Intel Xeon Phi coprocessors". Overview of architecture,

  8. CASL - The Michigan Parallel Characteristics Transport Code

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Michigan Parallel Characteristics Transport Code Verification of MPACT: The Michigan Parallel Characteristics Transport Code Benjamin Collins, Brendan Kochunas, Daniel Jabbay, Thomas Downar, William Martin Department of Nuclear Engineering and Radiological Sciences University of Michigan Andrew Godfrey Oak Ridge National Laboroatory MPACT (Michigan PArallel Characteristics Transport Code) is a new reactor analysis tool being developed at the University of Michigan as an advanced pin-resolved

  9. Parallel auto-correlative statistics with VTK.

    SciTech Connect (OSTI)

    Pebay, Philippe Pierre; Bennett, Janine Camille

    2013-08-01

    This report summarizes existing statistical engines in VTK and presents both the serial and parallel auto-correlative statistics engines. It is a sequel to [PT08, BPRT09b, PT09, BPT09, PT10] which studied the parallel descriptive, correlative, multi-correlative, principal component analysis, contingency, k-means, and order statistics engines. The ease of use of the new parallel auto-correlative statistics engine is illustrated by the means of C++ code snippets and algorithm verification is provided. This report justifies the design of the statistics engines with parallel scalability in mind, and provides scalability and speed-up analysis results for the autocorrelative statistics engine.

  10. Petascale Parallelization of the Gyrokinetic Toroidal Code

    SciTech Connect (OSTI)

    Ethier, Stephane; Adams, Mark; Carter, Jonathan; Oliker, Leonid

    2010-05-01

    The Gyrokinetic Toroidal Code (GTC) is a global, three-dimensional particle-in-cell application developed to study microturbulence in tokamak fusion devices. The global capability of GTC is unique, allowing researchers to systematically analyze important dynamics such as turbulence spreading. In this work we examine a new radial domain decomposition approach to allow scalability onto the latest generation of petascale systems. Extensive performance evaluation is conducted on three high performance computing systems: the IBM BG/P, the Cray XT4, and an Intel Xeon Cluster. Overall results show that the radial decomposition approach dramatically increases scalability, while reducing the memory footprint - allowing for fusion device simulations at an unprecedented scale. After a decade where high-end computing (HEC) was dominated by the rapid pace of improvements to processor frequencies, the performance of next-generation supercomputers is increasingly differentiated by varying interconnect designs and levels of integration. Understanding the tradeoffs of these system designs is a key step towards making effective petascale computing a reality. In this work, we examine a new parallelization scheme for the Gyrokinetic Toroidal Code (GTC) [?] micro-turbulence fusion application. Extensive scalability results and analysis are presented on three HEC systems: the IBM BlueGene/P (BG/P) at Argonne National Laboratory, the Cray XT4 at Lawrence Berkeley National Laboratory, and an Intel Xeon cluster at Lawrence Livermore National Laboratory. Overall results indicate that the new radial decomposition approach successfully attains unprecedented scalability to 131,072 BG/P cores by overcoming the memory limitations of the previous approach. The new version is well suited to utilize emerging petascale resources to access new regimes of physical phenomena.

  11. Composing Data Parallel Code for a SPARQL Graph Engine

    SciTech Connect (OSTI)

    Castellana, Vito G.; Tumeo, Antonino; Villa, Oreste; Haglin, David J.; Feo, John

    2013-09-08

    Big data analytics process large amount of data to extract knowledge from them. Semantic databases are big data applications that adopt the Resource Description Framework (RDF) to structure metadata through a graph-based representation. The graph based representation provides several benefits, such as the possibility to perform in memory processing with large amounts of parallelism. SPARQL is a language used to perform queries on RDF-structured data through graph matching. In this paper we present a tool that automatically translates SPARQL queries to parallel graph crawling and graph matching operations. The tool also supports complex SPARQL constructs, which requires more than basic graph matching for their implementation. The tool generates parallel code annotated with OpenMP pragmas for x86 Shared-memory Multiprocessors (SMPs). With respect to commercial database systems such as Virtuoso, our approach reduces memory occupation due to join operations and provides higher performance. We show the scaling of the automatically generated graph-matching code on a 48-core SMP.

  12. System and method for representing and manipulating three-dimensional objects on massively parallel architectures

    DOE Patents [OSTI]

    Karasick, Michael S.; Strip, David R.

    1996-01-01

    A parallel computing system is described that comprises a plurality of uniquely labeled, parallel processors, each processor capable of modelling a three-dimensional object that includes a plurality of vertices, faces and edges. The system comprises a front-end processor for issuing a modelling command to the parallel processors, relating to a three-dimensional object. Each parallel processor, in response to the command and through the use of its own unique label, creates a directed-edge (d-edge) data structure that uniquely relates an edge of the three-dimensional object to one face of the object. Each d-edge data structure at least includes vertex descriptions of the edge and a description of the one face. As a result, each processor, in response to the modelling command, operates upon a small component of the model and generates results, in parallel with all other processors, without the need for processor-to-processor intercommunication.

  13. System and method for representing and manipulating three-dimensional objects on massively parallel architectures

    DOE Patents [OSTI]

    Karasick, M.S.; Strip, D.R.

    1996-01-30

    A parallel computing system is described that comprises a plurality of uniquely labeled, parallel processors, each processor capable of modeling a three-dimensional object that includes a plurality of vertices, faces and edges. The system comprises a front-end processor for issuing a modeling command to the parallel processors, relating to a three-dimensional object. Each parallel processor, in response to the command and through the use of its own unique label, creates a directed-edge (d-edge) data structure that uniquely relates an edge of the three-dimensional object to one face of the object. Each d-edge data structure at least includes vertex descriptions of the edge and a description of the one face. As a result, each processor, in response to the modeling command, operates upon a small component of the model and generates results, in parallel with all other processors, without the need for processor-to-processor intercommunication. 8 figs.

  14. Final Report: Center for Programming Models for Scalable Parallel Computing

    SciTech Connect (OSTI)

    Mellor-Crummey, John

    2011-09-13

    As part of the Center for Programming Models for Scalable Parallel Computing, Rice University collaborated with project partners in the design, development and deployment of language, compiler, and runtime support for parallel programming models to support application development for the “leadership-class” computer systems at DOE national laboratories. Work over the course of this project has focused on the design, implementation, and evaluation of a second-generation version of Coarray Fortran. Research and development efforts of the project have focused on the CAF 2.0 language, compiler, runtime system, and supporting infrastructure. This has involved working with the teams that provide infrastructure for CAF that we rely on, implementing new language and runtime features, producing an open source compiler that enabled us to evaluate our ideas, and evaluating our design and implementation through the use of benchmarks. The report details the research, development, findings, and conclusions from this work.

  15. Buffered coscheduling for parallel programming and enhanced fault tolerance

    DOE Patents [OSTI]

    Petrini, Fabrizio; Feng, Wu-chun

    2006-01-31

    A computer implemented method schedules processor jobs on a network of parallel machine processors or distributed system processors. Control information communications generated by each process performed by each processor during a defined time interval is accumulated in buffers, where adjacent time intervals are separated by strobe intervals for a global exchange of control information. A global exchange of the control information communications at the end of each defined time interval is performed during an intervening strobe interval so that each processor is informed by all of the other processors of the number of incoming jobs to be received by each processor in a subsequent time interval. The buffered coscheduling method of this invention also enhances the fault tolerance of a network of parallel machine processors or distributed system processors

  16. Differences Between Distributed and Parallel Systems

    SciTech Connect (OSTI)

    Brightwell, R.; Maccabe, A.B.; Rissen, R.

    1998-10-01

    Distributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma.

  17. Broadcasting a message in a parallel computer

    DOE Patents [OSTI]

    Berg, Jeremy E.; Faraj, Ahmad A.

    2011-08-02

    Methods, systems, and products are disclosed for broadcasting a message in a parallel computer. The parallel computer includes a plurality of compute nodes connected together using a data communications network. The data communications network optimized for point to point data communications and is characterized by at least two dimensions. The compute nodes are organized into at least one operational group of compute nodes for collective parallel operations of the parallel computer. One compute node of the operational group assigned to be a logical root. Broadcasting a message in a parallel computer includes: establishing a Hamiltonian path along all of the compute nodes in at least one plane of the data communications network and in the operational group; and broadcasting, by the logical root to the remaining compute nodes, the logical root's message along the established Hamiltonian path.

  18. Automated Parallel Capillary Electrophoretic System

    DOE Patents [OSTI]

    Li, Qingbo; Kane, Thomas E.; Liu, Changsheng; Sonnenschein, Bernard; Sharer, Michael V.; Kernan, John R.

    2000-02-22

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  19. Xyce parallel electronic simulator : users' guide.

    SciTech Connect (OSTI)

    Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.; Santarelli, Keith R.; Fixel, Deborah A.; Coffey, Todd Stirling; Russo, Thomas V.; Schiek, Richard Louis; Warrender, Christina E.; Keiter, Eric Richard; Pawlowski, Roger Patrick

    2011-05-01

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers; (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only); and (4) Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing parallel implementation - which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The development of Xyce provides a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms) research and development can be performed. As a result, Xyce is a unique

  20. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Di Croce, A.M.; Draper, R.

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row. 5 figures.

  1. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Di Croce, A. Michael; Draper, Robert

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row.

  2. Parallel Climate Analysis Toolkit (ParCAT)

    SciTech Connect (OSTI)

    Smith, Brian Edward

    2013-06-30

    The parallel analysis toolkit (ParCAT) provides parallel statistical processing of large climate model simulation datasets. ParCAT provides parallel point-wise average calculations, frequency distributions, sum/differences of two datasets, and difference-of-average and average-of-difference for two datasets for arbitrary subsets of simulation time. ParCAT is a command-line utility that can be easily integrated in scripts or embedded in other application. ParCAT supports CMIP5 post-processed datasets as well as non-CMIP5 post-processed datasets. ParCAT reads and writes standard netCDF files.

  3. Distributed parallel messaging for multiprocessor systems

    DOE Patents [OSTI]

    Chen, Dong; Heidelberger, Philip; Salapura, Valentina; Senger, Robert M; Steinmacher-Burrow, Burhard; Sugawara, Yutaka

    2013-06-04

    A method and apparatus for distributed parallel messaging in a parallel computing system. The apparatus includes, at each node of a multiprocessor network, multiple injection messaging engine units and reception messaging engine units, each implementing a DMA engine and each supporting both multiple packet injection into and multiple reception from a network, in parallel. The reception side of the messaging unit (MU) includes a switch interface enabling writing of data of a packet received from the network to the memory system. The transmission side of the messaging unit, includes switch interface for reading from the memory system when injecting packets into the network.

  4. Stochastic Parallel PARticle Kinetic Simulator

    Energy Science and Technology Software Center (OSTI)

    2008-07-01

    SPPARKS is a kinetic Monte Carlo simulator which implements kinetic and Metropolis Monte Carlo solvers in a general way so that they can be hooked to applications of various kinds. Specific applications are implemented in SPPARKS as physical models which generate events (e.g. a diffusive hop or chemical reaction) and execute them one-by-one. Applications can run in paralle so long as the simulation domain can be partitoned spatially so that multiple events can be invokedmore » simultaneously. SPPARKS is used to model various kinds of mesoscale materials science scenarios such as grain growth, surface deposition and growth, and reaction kinetics. It can also be used to develop new Monte Carlo models that hook to the existing solver and paralle infrastructure provided by the code.« less

  5. Solid state pulsed power generator

    DOE Patents [OSTI]

    Tao, Fengfeng; Saddoughi, Seyed Gholamali; Herbon, John Thomas

    2014-02-11

    A power generator includes one or more full bridge inverter modules coupled to a semiconductor opening switch (SOS) through an inductive resonant branch. Each module includes a plurality of switches that are switched in a fashion causing the one or more full bridge inverter modules to drive the semiconductor opening switch SOS through the resonant circuit to generate pulses to a load connected in parallel with the SOS.

  6. Evaluating parallel relational databases for medical data analysis.

    SciTech Connect (OSTI)

    Rintoul, Mark Daniel; Wilson, Andrew T.

    2012-03-01

    Hospitals have always generated and consumed large amounts of data concerning patients, treatment and outcomes. As computers and networks have permeated the hospital environment it has become feasible to collect and organize all of this data. This raises naturally the question of how to deal with the resulting mountain of information. In this report we detail a proof-of-concept test using two commercially available parallel database systems to analyze a set of real, de-identified medical records. We examine database scalability as data sizes increase as well as responsiveness under load from multiple users.

  7. Parallel I/O in Practice

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    art. This tutorial sheds light on the state-of-the-art in parallel IO and provides the knowledge necessary for attendees to best leverage IO resources available to them. We...

  8. Asynchronous parallel pattern search for nonlinear optimization

    SciTech Connect (OSTI)

    P. D. Hough; T. G. Kolda; V. J. Torczon

    2000-01-01

    Parallel pattern search (PPS) can be quite useful for engineering optimization problems characterized by a small number of variables (say 10--50) and by expensive objective function evaluations such as complex simulations that take from minutes to hours to run. However, PPS, which was originally designed for execution on homogeneous and tightly-coupled parallel machine, is not well suited to the more heterogeneous, loosely-coupled, and even fault-prone parallel systems available today. Specifically, PPS is hindered by synchronization penalties and cannot recover in the event of a failure. The authors introduce a new asynchronous and fault tolerant parallel pattern search (AAPS) method and demonstrate its effectiveness on both simple test problems as well as some engineering optimization problems

  9. Parallel programming with PCN. Revision 1

    SciTech Connect (OSTI)

    Foster, I.; Tuecke, S.

    1991-12-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and C that allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. In includes both tutorial and reference material. It also presents the basic concepts that underly PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous FTP from Argonne National Laboratory in the directory pub/pcn at info.mcs.anl.gov (c.f. Appendix A).

  10. Feature Clustering for Accelerating Parallel Coordinate Descent

    SciTech Connect (OSTI)

    Scherrer, Chad; Tewari, Ambuj; Halappanavar, Mahantesh; Haglin, David J.

    2012-12-06

    We demonstrate an approach for accelerating calculation of the regularization path for L1 sparse logistic regression problems. We show the benefit of feature clustering as a preconditioning step for parallel block-greedy coordinate descent algorithms.

  11. Optimize Parallel Pumping Systems: Industrial Technologies Program...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... to operate the number of pumps needed to meet variable fow rate requirements effciently. ... Parallel pumps provide balanced or equal fow rates when the same models are used and their ...

  12. HOPSPACK: Hybrid Optimization Parallel Search Package.

    SciTech Connect (OSTI)

    Gray, Genetha A.; Kolda, Tamara G.; Griffin, Joshua; Taddy, Matt; Martinez-Canales, Monica

    2008-12-01

    In this paper, we describe the technical details of HOPSPACK (Hybrid Optimization Parallel SearchPackage), a new software platform which facilitates combining multiple optimization routines into asingle, tightly-coupled, hybrid algorithm that supports parallel function evaluations. The frameworkis designed such that existing optimization source code can be easily incorporated with minimalcode modification. By maintaining the integrity of each individual solver, the strengths and codesophistication of the original optimization package are retained and exploited.4

  13. Light beam frequency comb generator

    DOE Patents [OSTI]

    Priatko, G.J.; Kaskey, J.A.

    1992-11-24

    A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics. 2 figs.

  14. Light beam frequency comb generator

    DOE Patents [OSTI]

    Priatko, Gordon J.; Kaskey, Jeffrey A.

    1992-01-01

    A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics.

  15. High performance parallel computers for science: New developments at the Fermilab advanced computer program

    SciTech Connect (OSTI)

    Nash, T.; Areti, H.; Atac, R.; Biel, J.; Cook, A.; Deppe, J.; Edel, M.; Fischler, M.; Gaines, I.; Hance, R.

    1988-08-01

    Fermilab's Advanced Computer Program (ACP) has been developing highly cost effective, yet practical, parallel computers for high energy physics since 1984. The ACP's latest developments are proceeding in two directions. A Second Generation ACP Multiprocessor System for experiments will include $3500 RISC processors each with performance over 15 VAX MIPS. To support such high performance, the new system allows parallel I/O, parallel interprocess communication, and parallel host processes. The ACP Multi-Array Processor, has been developed for theoretical physics. Each $4000 node is a FORTRAN or C programmable pipelined 20 MFlops (peak), 10 MByte single board computer. These are plugged into a 16 port crossbar switch crate which handles both inter and intra crate communication. The crates are connected in a hypercube. Site oriented applications like lattice gauge theory are supported by system software called CANOPY, which makes the hardware virtually transparent to users. A 256 node, 5 GFlop, system is under construction. 10 refs., 7 figs.

  16. Implementation of Parallel Dynamic Simulation on Shared-Memory vs. Distributed-Memory Environments

    SciTech Connect (OSTI)

    Jin, Shuangshuang; Chen, Yousu; Wu, Di; Diao, Ruisheng; Huang, Zhenyu

    2015-12-09

    Power system dynamic simulation computes the system response to a sequence of large disturbance, such as sudden changes in generation or load, or a network short circuit followed by protective branch switching operation. It consists of a large set of differential and algebraic equations, which is computational intensive and challenging to solve using single-processor based dynamic simulation solution. High-performance computing (HPC) based parallel computing is a very promising technology to speed up the computation and facilitate the simulation process. This paper presents two different parallel implementations of power grid dynamic simulation using Open Multi-processing (OpenMP) on shared-memory platform, and Message Passing Interface (MPI) on distributed-memory clusters, respectively. The difference of the parallel simulation algorithms and architectures of the two HPC technologies are illustrated, and their performances for running parallel dynamic simulation are compared and demonstrated.

  17. Parallel Algorithms and Patterns (Technical Report) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Parallel Algorithms and Patterns Citation Details In-Document Search Title: Parallel Algorithms and Patterns Authors: Robey, Robert W. 1 + Show Author Affiliations Los Alamos ...

  18. Parallel Integral Curves (Book) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Book: Parallel Integral Curves Citation Details In-Document Search Title: Parallel Integral Curves Authors: Pugmire, Dave 1 ; Peterka, Tom 2 ; ...

  19. Linux Kernel Co-Scheduling For Bulk Synchronous Parallel Applications...

    Office of Scientific and Technical Information (OSTI)

    Linux Kernel Co-Scheduling For Bulk Synchronous Parallel Applications Citation Details In-Document Search Title: Linux Kernel Co-Scheduling For Bulk Synchronous Parallel ...

  20. Parallel phase-sensitive three-dimensional imaging camera

    DOE Patents [OSTI]

    Smithpeter, Colin L.; Hoover, Eddie R.; Pain, Bedabrata; Hancock, Bruce R.; Nellums, Robert O.

    2007-09-25

    An apparatus is disclosed for generating a three-dimensional (3-D) image of a scene illuminated by a pulsed light source (e.g. a laser or light-emitting diode). The apparatus, referred to as a phase-sensitive 3-D imaging camera utilizes a two-dimensional (2-D) array of photodetectors to receive light that is reflected or scattered from the scene and processes an electrical output signal from each photodetector in the 2-D array in parallel using multiple modulators, each having inputs of the photodetector output signal and a reference signal, with the reference signal provided to each modulator having a different phase delay. The output from each modulator is provided to a computational unit which can be used to generate intensity and range information for use in generating a 3-D image of the scene. The 3-D camera is capable of generating a 3-D image using a single pulse of light, or alternately can be used to generate subsequent 3-D images with each additional pulse of light.

  1. Environmental support to the clean coal technology program

    SciTech Connect (OSTI)

    Miller, R.L.

    1996-06-01

    Work during this period focused on the preparation for DOE`s Morgantown Energy Technology Center (METC) of a final Environmental Assessment (EA) for the Externally Fired Combined Cycle (EFCC) Project in Warren, Pennsylvania. Proposed by the Pennsylvania Electric Company (Penelec) and selected by DOE in the fifth solicitation of the CCT Program, the project would be sited at one of the two units at Penelec`s Warren Station. The EFCC Project proposes to replace two existing boilers with a new {open_quotes}power island{close_quotes} consisting of a staged coal combustor, slag screen, heat exchanger, an indirectly fired gas turbine, and a heat recovery steam generator. Subsequently, Unit 2 would operate in combined-cycle mode using the new gas turbine and the existing steam turbine simultaneously. The gas turbine would generate 25 megawatts of electricity so that Unit 2 output would increase from the existing 48 megawatts generated by the steam turbine to a total of 73 megawatts. Operation of a conventional flue gas desulfurization dry scrubber as part of the EFCC technology is expected to decrease SO{sub 2} emissions by 90% per kilowatt-hour of electricity generated, and NO{sub x} emissions are anticipated to be 60% less per kilowatt-hour of electricity generated because of the staged combustor. Because the EFCC technology would be more efficient, less carbon dioxide (CO{sub 2}) would be emitted to the atmosphere per kilowatt-hour of electricity produced.

  2. Java Parallel Secure Stream for Grid Computing

    SciTech Connect (OSTI)

    Chen, Jie; Akers, Walter; Chen, Ying; Watson, William

    2001-09-01

    The emergence of high speed wide area networks makes grid computing a reality. However grid applications that need reliable data transfer still have difficulties to achieve optimal TCP performance due to network tuning of TCP window size to improve the bandwidth and to reduce latency on a high speed wide area network. This paper presents a pure Java package called JPARSS (Java Par-allel Secure Stream) that divides data into partitions that are sent over several parallel Java streams simultaneously and allows Java or Web applications to achieve optimal TCP performance in a gird environment without the necessity of tuning the TCP window size. Several experimental results are provided to show that using parallel stream is more effective than tuning TCP window size. In addi-tion X.509 certificate based single sign-on mechanism and SSL based connection establishment are integrated into this package. Finally a few applications using this package will be discussed.

  3. GRIDS: Grid-Scale Rampable Intermittent Dispatchable Storage

    SciTech Connect (OSTI)

    2010-09-01

    GRIDS Project: The 12 projects that comprise ARPA-Es GRIDS Project, short for Grid-Scale Rampable Intermittent Dispatchable Storage, are developing storage technologies that can store renewable energy for use at any location on the grid at an investment cost less than $100 per kilowatt hour. Flexible, large-scale storage would create a stronger and more robust electric grid by enabling renewables to contribute to reliable power generation.

  4. Ramona Band of Cahuilla Mission Indians- 2002 Project

    Broader source: Energy.gov [DOE]

    The Ramona Band of Cahuilla Mission Indians ("Ramona Band" or "tribe") will be the first tribe to develop its entire reservation off-grid, using renewable energy as the primary power source. The tribe will purchase and install the primary components for a 65-80 kilowatt-hours per day central wind/PV/propane generator hybrid system that will power the reservation's housing, offices, ecotourism, and training businesses. The electricity is planned to be distributed through an underground mini-grid.

  5. Project Reports for Ramona Band of Cahuilla Mission Indians- 2002 Project

    Broader source: Energy.gov [DOE]

    The Ramona Band of Cahuilla Mission Indians ("Ramona Band" or "tribe") will be the first tribe to develop its entire reservation off-grid, using renewable energy as the primary power source. The tribe will purchase and install the primary components for a 65-80 kilowatt-hours per day central wind/PV/propane generator hybrid system that will power the reservation's housing, offices, ecotourism, and training businesses. The electricity is planned to be distributed through an underground mini-grid.

  6. Under Secretary Klotz delivers remarks at PREP ribbon-cutting | National

    National Nuclear Security Administration (NNSA)

    Nuclear Security Administration | (NNSA) Under Secretary Klotz delivers remarks at PREP ribbon-cutting Wednesday, June 18, 2014 - 1:23pm Under Secretary Klotz delivered remarks at the Pantex Renewable Energy Project (PREP) ribbon-cutting this week. PREP establishes the largest federally-owned wind farm in the country and will generate approximately 47 million kilowatt-hours of electricity annually, more than 60 percent of the electricity needed for Pantex. The project will reduce CO2

  7. Xyce parallel electronic simulator release notes.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Hoekstra, Robert John; Mei, Ting; Russo, Thomas V.; Schiek, Richard Louis; Thornquist, Heidi K.; Rankin, Eric Lamont; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01

    The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. Specific requirements include, among others, the ability to solve extremely large circuit problems by supporting large-scale parallel computing platforms, improved numerical performance and object-oriented code design and implementation. The Xyce release notes describe: Hardware and software requirements New features and enhancements Any defects fixed since the last release Current known defects and defect workarounds For up-to-date information not available at the time these notes were produced, please visit the Xyce web page at http://www.cs.sandia.gov/xyce.

  8. Parallel Implementation of Power System Dynamic Simulation

    SciTech Connect (OSTI)

    Jin, Shuangshuang; Huang, Zhenyu; Diao, Ruisheng; Wu, Di; Chen, Yousu

    2013-07-21

    Dynamic simulation of power system transient stability is important for planning, monitoring, operation, and control of electrical power systems. However, modeling the system dynamics and network involves the computationally intensive time-domain solution of numerous differential and algebraic equations (DAE). This results in a transient stability implementation that may not maintain the real-time constraints of an online security assessment. This paper presents a parallel implementation of the dynamic simulation on a high-performance computing (HPC) platform using parallel simulation algorithms and computation architectures. It enables the simulation to run even faster than real time, enabling the look-ahead capability of upcoming stability problems in the power grid.

  9. Berkeley Unified Parallel C (UPC) Compiler

    Energy Science and Technology Software Center (OSTI)

    2003-04-06

    This program is a portable, open-source, compiler for the UPC language, which is based on the Open64 framework, and has extensive support for optimizations. This compiler operated by translating UPC into ANS/ISO C for compilation by a native compiler and linking with a UPC Runtime Library. This design eases portability to both shared and distributed memory parallel architectures. For proper operation the "Berkeley Unified Parallel C (UPC) Runtime Library" and its dependencies are required. Compatiblemore » replacements which implement "The Berkeley UPC Runtime Specification" are possible.« less

  10. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2013-11-12

    Data communications in a parallel active messaging interface (`PAMI`) of a parallel computer composed of compute nodes that execute a parallel application, each compute node including application processors that execute the parallel application and at least one management processor dedicated to gathering information regarding data communications. The PAMI is composed of data communications endpoints, each endpoint composed of a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes and the endpoints coupled for data communications through the PAMI and through data communications resources. Embodiments function by gathering call site statistics describing data communications resulting from execution of data communications instructions and identifying in dependence upon the call cite statistics a data communications algorithm for use in executing a data communications instruction at a call site in the parallel application.

  11. Parallel programming with PCN. Revision 2

    SciTech Connect (OSTI)

    Foster, I.; Tuecke, S.

    1993-01-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and Cthat allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. It includes both tutorial and reference material. It also presents the basic concepts that underlie PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous ftp from Argonne National Laboratory in the directory pub/pcn at info.mcs. ani.gov (cf. Appendix A). This version of this document describes PCN version 2.0, a major revision of the PCN programming system. It supersedes earlier versions of this report.

  12. Linked-View Parallel Coordinate Plot Renderer

    Energy Science and Technology Software Center (OSTI)

    2011-06-28

    This software allows multiple linked views for interactive querying via map-based data selection, bar chart analytic overlays, and high dynamic range (HDR) line renderings. The major component of the visualization package is a parallel coordinate renderer with binning, curved layouts, shader-based rendering, and other techniques to allow interactive visualization of multidimensional data.

  13. The parallel virtual file system for portals.

    SciTech Connect (OSTI)

    Schutt, James Alan

    2004-04-01

    This report presents the result of an effort to re-implement the Parallel Virtual File System (PVFS) using Portals as the transport. This report provides short overviews of PVFS and Portals, and describes the design and implementation of PVFS over Portals. Finally, the results of performance testing of both stock PVFS and PVFS over Portals are presented.

  14. Message passing with parallel queue traversal

    DOE Patents [OSTI]

    Underwood, Keith D.; Brightwell, Ronald B.; Hemmert, K. Scott

    2012-05-01

    In message passing implementations, associative matching structures are used to permit list entries to be searched in parallel fashion, thereby avoiding the delay of linear list traversal. List management capabilities are provided to support list entry turnover semantics and priority ordering semantics.

  15. Parallel Performance of a Combustion Chemistry Simulation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Skinner, Gregg; Eigenmann, Rudolf

    1995-01-01

    We used a description of a combustion simulation's mathematical and computational methods to develop a version for parallel execution. The result was a reasonable performance improvement on small numbers of processors. We applied several important programming techniques, which we describe, in optimizing the application. This work has implications for programming languages, compiler design, and software engineering.

  16. Parallel stitching of 2D materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ling, Xi; Wu, Lijun; Lin, Yuxuan; Ma, Qiong; Wang, Ziqiang; Song, Yi; Yu, Lili; Huang, Shengxi; Fang, Wenjing; Zhang, Xu; et al

    2016-01-27

    Diverse parallel stitched 2D heterostructures, including metal–semiconductor, semiconductor–semiconductor, and insulator–semiconductor, are synthesized directly through selective “sowing” of aromatic molecules as the seeds in the chemical vapor deposition (CVD) method. Lastly, the methodology enables the large-scale fabrication of lateral heterostructures, which offers tremendous potential for its application in integrated circuits.

  17. Parallel Algebraic Multigrids for Structural mechanics

    SciTech Connect (OSTI)

    Brezina, M; Tong, C; Becker, R

    2004-05-11

    This paper presents the results of a comparison of three parallel algebraic multigrid (AMG) preconditioners for structural mechanics applications. In particular, they are interested in investigating both the scalability and robustness of the preconditioners. Numerical results are given for a range of structural mechanics problems with various degrees of difficulty.

  18. Collectively loading an application in a parallel computer

    DOE Patents [OSTI]

    Aho, Michael E.; Attinella, John E.; Gooding, Thomas M.; Miller, Samuel J.; Mundy, Michael B.

    2016-01-05

    Collectively loading an application in a parallel computer, the parallel computer comprising a plurality of compute nodes, including: identifying, by a parallel computer control system, a subset of compute nodes in the parallel computer to execute a job; selecting, by the parallel computer control system, one of the subset of compute nodes in the parallel computer as a job leader compute node; retrieving, by the job leader compute node from computer memory, an application for executing the job; and broadcasting, by the job leader to the subset of compute nodes in the parallel computer, the application for executing the job.

  19. Multitasking TORT under UNICOS: Parallel performance models and measurements

    SciTech Connect (OSTI)

    Barnett, A.; Azmy, Y.Y.

    1999-09-27

    The existing parallel algorithms in the TORT discrete ordinates code were updated to function in a UNICOS environment. A performance model for the parallel overhead was derived for the existing algorithms. The largest contributors to the parallel overhead were identified and a new algorithm was developed. A parallel overhead model was also derived for the new algorithm. The results of the comparison of parallel performance models were compared to applications of the code to two TORT standard test problems and a large production problem. The parallel performance models agree well with the measured parallel overhead.

  20. Generation Planning (pbl/generation)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generation Hydro Power Wind Power Monthly GSP BPA White Book Dry Year Tools Firstgov Generation Planning Thumbnail image of BPA White Book BPA White Book (1998-2014) Draft Dry...

  1. Electrostatic generator/motor configurations

    DOE Patents [OSTI]

    Post, Richard F

    2014-02-04

    Electrostatic generators/motors designs are provided that generally may include a first cylindrical stator centered about a longitudinal axis; a second cylindrical stator centered about the axis, a first cylindrical rotor centered about the axis and located between the first cylindrical stator and the second cylindrical stator. The first cylindrical stator, the second cylindrical stator and the first cylindrical rotor may be concentrically aligned. A magnetic field having field lines about parallel with the longitudinal axis is provided.

  2. Users manual for the Chameleon parallel programming tools

    SciTech Connect (OSTI)

    Gropp, W.; Smith, B.

    1993-06-01

    Message passing is a common method for writing programs for distributed-memory parallel computers. Unfortunately, the lack of a standard for message passing has hampered the construction of portable and efficient parallel programs. In an attempt to remedy this problem, a number of groups have developed their own message-passing systems, each with its own strengths and weaknesses. Chameleon is a second-generation system of this type. Rather than replacing these existing systems, Chameleon is meant to supplement them by providing a uniform way to access many of these systems. Chameleon`s goals are to (a) be very lightweight (low over-head), (b) be highly portable, and (c) help standardize program startup and the use of emerging message-passing operations such as collective operations on subsets of processors. Chameleon also provides a way to port programs written using PICL or Intel NX message passing to other systems, including collections of workstations. Chameleon is tracking the Message-Passing Interface (MPI) draft standard and will provide both an MPI implementation and an MPI transport layer. Chameleon provides support for heterogeneous computing by using p4 and PVM. Chameleon`s support for homogeneous computing includes the portable libraries p4, PICL, and PVM and vendor-specific implementation for Intel NX, IBM EUI (SP-1), and Thinking Machines CMMD (CM-5). Support for Ncube and PVM 3.x is also under development.

  3. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-02-11

    Data communications in a parallel active messaging interface ('PAMI') or a parallel computer, the parallel computer including a plurality of compute nodes that execute a parallel application, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution of a compute node, including specification of a client, a context, and a task, the compute nodes and the endpoints coupled for data communications instruction, the instruction characterized by instruction type, the instruction specifying a transmission of transfer data from the origin endpoint to a target endpoint and transmitting, in accordance witht the instruction type, the transfer data from the origin endpoin to the target endpoint.

  4. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2013-10-29

    Data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the parallel computer including a plurality of compute nodes that execute a parallel application, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes and the endpoints coupled for data communications through the PAMI and through data communications resources, including receiving in an origin endpoint of the PAMI a data communications instruction, the instruction characterized by an instruction type, the instruction specifying a transmission of transfer data from the origin endpoint to a target endpoint and transmitting, in accordance with the instruction type, the transfer data from the origin endpoint to the target endpoint.

  5. Parallel pulse processing and data acquisition for high speed, low error flow cytometry

    DOE Patents [OSTI]

    Engh, G.J. van den; Stokdijk, W.

    1992-09-22

    A digitally synchronized parallel pulse processing and data acquisition system for a flow cytometer has multiple parallel input channels with independent pulse digitization and FIFO storage buffer. A trigger circuit controls the pulse digitization on all channels. After an event has been stored in each FIFO, a bus controller moves the oldest entry from each FIFO buffer onto a common data bus. The trigger circuit generates an ID number for each FIFO entry, which is checked by an error detection circuit. The system has high speed and low error rate. 17 figs.

  6. Parallel pulse processing and data acquisition for high speed, low error flow cytometry

    DOE Patents [OSTI]

    van den Engh, Gerrit J.; Stokdijk, Willem

    1992-01-01

    A digitally synchronized parallel pulse processing and data acquisition system for a flow cytometer has multiple parallel input channels with independent pulse digitization and FIFO storage buffer. A trigger circuit controls the pulse digitization on all channels. After an event has been stored in each FIFO, a bus controller moves the oldest entry from each FIFO buffer onto a common data bus. The trigger circuit generates an ID number for each FIFO entry, which is checked by an error detection circuit. The system has high speed and low error rate.

  7. Locating hardware faults in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

    2010-04-13

    Locating hardware faults in a parallel computer, including defining within a tree network of the parallel computer two or more sets of non-overlapping test levels of compute nodes of the network that together include all the data communications links of the network, each non-overlapping test level comprising two or more adjacent tiers of the tree; defining test cells within each non-overlapping test level, each test cell comprising a subtree of the tree including a subtree root compute node and all descendant compute nodes of the subtree root compute node within a non-overlapping test level; performing, separately on each set of non-overlapping test levels, an uplink test on all test cells in a set of non-overlapping test levels; and performing, separately from the uplink tests and separately on each set of non-overlapping test levels, a downlink test on all test cells in a set of non-overlapping test levels.

  8. Impact analysis on a massively parallel computer

    SciTech Connect (OSTI)

    Zacharia, T.; Aramayo, G.A.

    1994-06-01

    Advanced mathematical techniques and computer simulation play a major role in evaluating and enhancing the design of beverage cans, industrial, and transportation containers for improved performance. Numerical models are used to evaluate the impact requirements of containers used by the Department of Energy (DOE) for transporting radioactive materials. Many of these models are highly compute-intensive. An analysis may require several hours of computational time on current supercomputers despite the simplicity of the models being studied. As computer simulations and materials databases grow in complexity, massively parallel computers have become important tools. Massively parallel computational research at the Oak Ridge National Laboratory (ORNL) and its application to the impact analysis of shipping containers is briefly described in this paper.

  9. Parallel machine architecture for production rule systems

    DOE Patents [OSTI]

    Allen, Jr., John D.; Butler, Philip L.

    1989-01-01

    A parallel processing system for production rule programs utilizes a host processor for storing production rule right hand sides (RHS) and a plurality of rule processors for storing left hand sides (LHS). The rule processors operate in parallel in the recognize phase of the system recognize -Act Cycle to match their respective LHS's against a stored list of working memory elements (WME) in order to find a self consistent set of WME's. The list of WME is dynamically varied during the Act phase of the system in which the host executes or fires rule RHS's for those rules for which a self-consistent set has been found by the rule processors. The host transmits instructions for creating or deleting working memory elements as dictated by the rule firings until the rule processors are unable to find any further self-consistent working memory element sets at which time the production rule system is halted.

  10. Parallel processor-based raster graphics system architecture

    DOE Patents [OSTI]

    Littlefield, Richard J.

    1990-01-01

    An apparatus for generating raster graphics images from the graphics command stream includes a plurality of graphics processors connected in parallel, each adapted to receive any part of the graphics command stream for processing the command stream part into pixel data. The apparatus also includes a frame buffer for mapping the pixel data to pixel locations and an interconnection network for interconnecting the graphics processors to the frame buffer. Through the interconnection network, each graphics processor may access any part of the frame buffer concurrently with another graphics processor accessing any other part of the frame buffer. The plurality of graphics processors can thereby transmit concurrently pixel data to pixel locations in the frame buffer.

  11. Distributed Generation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Untapped Value of Backup Generation While new guidelines and regulations such as IEEE (Institute of Electrical and Electronics Engineers) 1547 have come a long way in addressing interconnection standards for distributed generation, utilities have largely overlooked the untapped potential of these resources. Under certain conditions, these units (primarily backup generators) represent a significant source of power that can deliver utility services at lower costs than traditional centralized

  12. FORTRAN Extensions for Modular Parallel Processing

    Energy Science and Technology Software Center (OSTI)

    1996-01-12

    FORTRAN M is a small set of extensions to FORTRAN that supports a modular approach to the construction of sequential and parallel programs. FORTRAN M programs use channels to plug together processes which may be written in FORTRAN M or FORTRAN 77. Processes communicate by sending and receiving messages on channels. Channels and processes can be created dynamically, but programs remain deterministic unless specialized nondeterministic constructs are used.

  13. Parallel Integrated Thermal Management - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vehicles and Fuels Vehicles and Fuels Early Stage R&D Early Stage R&D Find More Like This Return to Search Parallel Integrated Thermal Management National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary Many current cooling systems for hybrid electric vehicles (HEVs) with a high power electric drive system utilize a low temperature liquid cooling loop for cooling the power electronics system and electric machines associated with the electric

  14. Parallel Heuristics for Scalable Community Detection

    SciTech Connect (OSTI)

    Lu, Howard; Kalyanaraman, Anantharaman; Halappanavar, Mahantesh; Choudhury, Sutanay

    2014-05-17

    Community detection has become a fundamental operation in numerous graph-theoretic applications. It is used to reveal natural divisions that exist within real world networks without imposing prior size or cardinality constraints on the set of communities. Despite its potential for application, there is only limited support for community detection on large-scale parallel computers, largely owing to the irregular and inherently sequential nature of the underlying heuristics. In this paper, we present parallelization heuristics for fast community detection using the Louvain method as the serial template. The Louvain method is an iterative heuristic for modularity optimization. Originally developed by Blondel et al. in 2008, the method has become increasingly popular owing to its ability to detect high modularity community partitions in a fast and memory-efficient manner. However, the method is also inherently sequential, thereby limiting its scalability to problems that can be solved on desktops. Here, we observe certain key properties of this method that present challenges for its parallelization, and consequently propose multiple heuristics that are designed to break the sequential barrier. Our heuristics are agnostic to the underlying parallel architecture. For evaluation purposes, we implemented our heuristics on shared memory (OpenMP) and distributed memory (MapReduce-MPI) machines, and tested them over real world graphs derived from multiple application domains (internet, biological, natural language processing). Experimental results demonstrate the ability of our heuristics to converge to high modularity solutions comparable to those output by the serial algorithm in nearly the same number of iterations, while also drastically reducing time to solution.

  15. Runtime System Library for Parallel Weather Modules

    Energy Science and Technology Software Center (OSTI)

    1997-07-22

    RSL is a Fortran-callable runtime library for use in implementing regular-grid weather forecast models, with nesting, on scalable distributed memory parallel computers. It provides high-level routines for finite-difference stencil communications and inter-domain exchange of data for nested forcing and feedback. RSL supports a unique point-wise domain-decomposition strategy to facilitate load-balancing.

  16. Parallel Molecular Dynamics Program for Molecules

    Energy Science and Technology Software Center (OSTI)

    1995-03-07

    ParBond is a parallel classical molecular dynamics code that models bonded molecular systems, typically of an organic nature. It uses classical force fields for both non-bonded Coulombic and Van der Waals interactions and for 2-, 3-, and 4-body bonded (bond, angle, dihedral, and improper) interactions. It integrates Newton''s equation of motion for the molecular system and evaluates various thermodynamical properties of the system as it progresses.

  17. Parallel log structured file system collective buffering to achieve a compact representation of scientific and/or dimensional data

    DOE Patents [OSTI]

    Grider, Gary A.; Poole, Stephen W.

    2015-09-01

    Collective buffering and data pattern solutions are provided for storage, retrieval, and/or analysis of data in a collective parallel processing environment. For example, a method can be provided for data storage in a collective parallel processing environment. The method comprises receiving data to be written for a plurality of collective processes within a collective parallel processing environment, extracting a data pattern for the data to be written for the plurality of collective processes, generating a representation describing the data pattern, and saving the data and the representation.

  18. Parallel Environment for the Creation of Stochastics 1.0

    Energy Science and Technology Software Center (OSTI)

    2011-01-06

    PECOS is a computational library for creating and manipulating realizations of stochastic quantities, including scalar uncertain variables, random fields, and stochastic processes. It offers a unified interface to univariate and multivariate polynomial approximations using either orthogonal or interpolation polynomials; numerical integration drivers for Latin hypercube sampling, quadrature, cubature, and sparse grids; and fast Fourier transforms using third party libraries. The PECOS core also offers statistical utilities and transformations between various representations of stochastic uncertainty. PECOSmore » provides a C++ API through which users can generate and transform realizations of stochastic quantities. It is currently used by Sandia’s DAKOTA, Stokhos, and Encore software packages for uncertainty quantification and verification. PECOS generates random sample sets and multi-dimensional integration grids, typically used in forward propagation of scalar uncertainty in computational models (uncertainty quantification (UQ)). PECOS also generates samples of random fields (RFs) and stochastic processes (SPs) from a set of user-defined power spectral densities (PSDs). The RF/SP may be either Gaussian or non-Gaussian and either stationary or nonstationary, and the resulting sample is intended for run-time query by parallel finite element simulation codes. Finally, PECOS supports nonlinear transformations of random variables via the Nataf transformation and extensions.« less

  19. Distributed Generation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and regulations such as IEEE (Institute of Electrical and Electronics Engineers) 1547 have come a long way in addressing interconnection standards for distributed generation, ...

  20. Xyce(™) Parallel Electronic Simulator

    Energy Science and Technology Software Center (OSTI)

    2013-10-03

    The Xyce Parallel Electronic Simulator simulates electronic circuit behavior in DC, AC, HB, MPDE and transient mode using standard analog (DAE) and/or device (PDE) device models including several age and radiation aware devices. It supports a variety of computing platforms (both serial and parallel) computers. Lastly, it uses a variety of modern solution algorithms dynamic parallel load-balancing and iterative solvers.! ! Xyce is primarily used to simulate the voltage and current behavior of a circuitmore » network (a network of electronic devices connected via a conductive network). As a tool, it is mainly used for the design and analysis of electronic circuits.! ! Kirchoff's conservation laws are enforced over a network using modified nodal analysis. This results in a set of differential algebraic equations (DAEs). The resulting nonlinear problem is solved iteratively using a fully coupled Newton method, which in turn results in a linear system that is solved by either a standard sparse-direct solver or iteratively using Trilinos linear solver packages, also developed at Sandia National Laboratories.« less

  1. Xyce parallel electronic simulator : reference guide.

    SciTech Connect (OSTI)

    Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.; Santarelli, Keith R.; Fixel, Deborah A.; Coffey, Todd Stirling; Russo, Thomas V.; Schiek, Richard Louis; Warrender, Christina E.; Keiter, Eric Richard; Pawlowski, Roger Patrick

    2011-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide. The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. It is targeted specifically to run on large-scale parallel computing platforms but also runs well on a variety of architectures including single processor workstations. It also aims to support a variety of devices and models specific to Sandia needs. This document is intended to complement the Xyce Users Guide. It contains comprehensive, detailed information about a number of topics pertinent to the usage of Xyce. Included in this document is a netlist reference for the input-file commands and elements supported within Xyce; a command line reference, which describes the available command line arguments for Xyce; and quick-references for users of other circuit codes, such as Orcad's PSpice and Sandia's ChileSPICE.

  2. MASSIVE HYBRID PARALLELISM FOR FULLY IMPLICIT MULTIPHYSICS

    SciTech Connect (OSTI)

    Cody J. Permann; David Andrs; John W. Peterson; Derek R. Gaston

    2013-05-01

    As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided.

  3. A mirror for lab-based quasi-monochromatic parallel x-rays

    SciTech Connect (OSTI)

    Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jeon, Insu; Jung, Jin-Ho; Jin, Gye-Hwan; Kim, Sung Youb

    2014-09-15

    A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

  4. Storing files in a parallel computing system based on user-specified parser function

    DOE Patents [OSTI]

    Faibish, Sorin; Bent, John M; Tzelnic, Percy; Grider, Gary; Manzanares, Adam; Torres, Aaron

    2014-10-21

    Techniques are provided for storing files in a parallel computing system based on a user-specified parser function. A plurality of files generated by a distributed application in a parallel computing system are stored by obtaining a parser from the distributed application for processing the plurality of files prior to storage; and storing one or more of the plurality of files in one or more storage nodes of the parallel computing system based on the processing by the parser. The plurality of files comprise one or more of a plurality of complete files and a plurality of sub-files. The parser can optionally store only those files that satisfy one or more semantic requirements of the parser. The parser can also extract metadata from one or more of the files and the extracted metadata can be stored with one or more of the plurality of files and used for searching for files.

  5. Magnetohydrodynamic generator electrode

    DOE Patents [OSTI]

    Marchant, David D.; Killpatrick, Don H.; Herman, Harold; Kuczen, Kenneth D.

    1979-01-01

    An improved electrode for use as a current collector in the channel of a magnetohydrodynamid (MHD) generator utilizes an elongated monolithic cap of dense refractory material compliantly mounted to the MHD channel frame for collecting the current. The cap has a central longitudinal channel which contains a first layer of porous refractory ceramic as a high-temperature current leadout from the cap and a second layer of resilient wire mesh in contact with the first layer as a low-temperature current leadout between the first layer and the frame. Also described is a monolithic ceramic insulator compliantly mounted to the frame parallel to the electrode by a plurality of flexible metal strips.

  6. Characterizing the parallelism in rule-based expert systems

    SciTech Connect (OSTI)

    Douglass, R.J.

    1984-01-01

    A brief review of two classes of rule-based expert systems is presented, followed by a detailed analysis of potential sources of parallelism at the production or rule level, the subrule level (including match, select, and act parallelism), and at the search level (including AND, OR, and stream parallelism). The potential amount of parallelism from each source is discussed and characterized in terms of its granularity, inherent serial constraints, efficiency, speedup, dynamic behavior, and communication volume, frequency, and topology. Subrule parallelism will yield, at best, two- to tenfold speedup, and rule level parallelism will yield a modest speedup on the order of 5 to 10 times. Rule level can be combined with OR, AND, and stream parallelism in many instances to yield further parallel speedups.

  7. A Massively Parallel Solver for the Mechanical Harmonic Analysis...

    Office of Scientific and Technical Information (OSTI)

    Details In-Document Search Title: A Massively Parallel Solver for the Mechanical Harmonic Analysis of Accelerator Cavities ACE3P is a 3D massively parallel simulation suite that...

  8. SimFS: A Large Scale Parallel File System Simulator

    Energy Science and Technology Software Center (OSTI)

    2011-08-30

    The software provides both framework and tools to simulate a large-scale parallel file system such as Lustre.

  9. Parallelizing AT with MatlabMPI

    SciTech Connect (OSTI)

    Li, Evan Y.; /Brown U. /SLAC

    2011-06-22

    The Accelerator Toolbox (AT) is a high-level collection of tools and scripts specifically oriented toward solving problems dealing with computational accelerator physics. It is integrated into the MATLAB environment, which provides an accessible, intuitive interface for accelerator physicists, allowing researchers to focus the majority of their efforts on simulations and calculations, rather than programming and debugging difficulties. Efforts toward parallelization of AT have been put in place to upgrade its performance to modern standards of computing. We utilized the packages MatlabMPI and pMatlab, which were developed by MIT Lincoln Laboratory, to set up a message-passing environment that could be called within MATLAB, which set up the necessary pre-requisites for multithread processing capabilities. On local quad-core CPUs, we were able to demonstrate processor efficiencies of roughly 95% and speed increases of nearly 380%. By exploiting the efficacy of modern-day parallel computing, we were able to demonstrate incredibly efficient speed increments per processor in AT's beam-tracking functions. Extrapolating from prediction, we can expect to reduce week-long computation runtimes to less than 15 minutes. This is a huge performance improvement and has enormous implications for the future computing power of the accelerator physics group at SSRL. However, one of the downfalls of parringpass is its current lack of transparency; the pMatlab and MatlabMPI packages must first be well-understood by the user before the system can be configured to run the scripts. In addition, the instantiation of argument parameters requires internal modification of the source code. Thus, parringpass, cannot be directly run from the MATLAB command line, which detracts from its flexibility and user-friendliness. Future work in AT's parallelization will focus on development of external functions and scripts that can be called from within MATLAB and configured on multiple nodes, while

  10. Large-eddy simulation of the Rayleigh-Taylor instability on a massively parallel computer

    SciTech Connect (OSTI)

    Amala, P.A.K.

    1995-03-01

    A computational model for the solution of the three-dimensional Navier-Stokes equations is developed. This model includes a turbulence model: a modified Smagorinsky eddy-viscosity with a stochastic backscatter extension. The resultant equations are solved using finite difference techniques: the second-order explicit Lax-Wendroff schemes. This computational model is implemented on a massively parallel computer. Programming models on massively parallel computers are next studied. It is desired to determine the best programming model for the developed computational model. To this end, three different codes are tested on a current massively parallel computer: the CM-5 at Los Alamos. Each code uses a different programming model: one is a data parallel code; the other two are message passing codes. Timing studies are done to determine which method is the fastest. The data parallel approach turns out to be the fastest method on the CM-5 by at least an order of magnitude. The resultant code is then used to study a current problem of interest to the computational fluid dynamics community. This is the Rayleigh-Taylor instability. The Lax-Wendroff methods handle shocks and sharp interfaces poorly. To this end, the Rayleigh-Taylor linear analysis is modified to include a smoothed interface. The linear growth rate problem is then investigated. Finally, the problem of the randomly perturbed interface is examined. Stochastic backscatter breaks the symmetry of the stationary unstable interface and generates a mixing layer growing at the experimentally observed rate. 115 refs., 51 figs., 19 tabs.

  11. Parallel State Estimation Assessment with Practical Data

    SciTech Connect (OSTI)

    Chen, Yousu; Jin, Shuangshuang; Rice, Mark J.; Huang, Zhenyu

    2014-10-31

    This paper presents a full-cycle parallel state estimation (PSE) implementation using a preconditioned conjugate gradient algorithm. The developed code is able to solve large-size power system state estimation within 5 seconds using real-world data, comparable to the Supervisory Control And Data Acquisition (SCADA) rate. This achievement allows the operators to know the system status much faster to help improve grid reliability. Case study results of the Bonneville Power Administration (BPA) system with real measurements are presented. The benefits of fast state estimation are also discussed.

  12. A brief parallel I/O tutorial.

    SciTech Connect (OSTI)

    Ward, H. Lee

    2010-03-01

    This document provides common best practices for the efficient utilization of parallel file systems for analysts and application developers. A multi-program, parallel supercomputer is able to provide effective compute power by aggregating a host of lower-power processors using a network. The idea, in general, is that one either constructs the application to distribute parts to the different nodes and processors available and then collects the result (a parallel application), or one launches a large number of small jobs, each doing similar work on different subsets (a campaign). The I/O system on these machines is usually implemented as a tightly-coupled, parallel application itself. It is providing the concept of a 'file' to the host applications. The 'file' is an addressable store of bytes and that address space is global in nature. In essence, it is providing a global address space. Beyond the simple reality that the I/O system is normally composed of a small, less capable, collection of hardware, that concept of a global address space will cause problems if not very carefully utilized. How much of a problem and the ways in which those problems manifest will be different, but that it is problem prone has been well established. Worse, the file system is a shared resource on the machine - a system service. What an application does when it uses the file system impacts all users. It is not the case that some portion of the available resource is reserved. Instead, the I/O system responds to requests by scheduling and queuing based on instantaneous demand. Using the system well contributes to the overall throughput on the machine. From a solely self-centered perspective, using it well reduces the time that the application or campaign is subject to impact by others. The developer's goal should be to accomplish I/O in a way that minimizes interaction with the I/O system, maximizes the amount of data moved per call, and provides the I/O system the most information about

  13. Carbothermic reduction with parallel heat sources

    DOE Patents [OSTI]

    Troup, Robert L.; Stevenson, David T.

    1984-12-04

    Disclosed are apparatus and method of carbothermic direct reduction for producing an aluminum alloy from a raw material mix including aluminum oxide, silicon oxide, and carbon wherein parallel heat sources are provided by a combustion heat source and by an electrical heat source at essentially the same position in the reactor, e.g., such as at the same horizontal level in the path of a gravity-fed moving bed in a vertical reactor. The present invention includes providing at least 79% of the heat energy required in the process by the electrical heat source.

  14. Requirements for Parallel I/O,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Requirements for Parallel I/O, ! Visualization and Analysis Prabhat 1 , Q uincey K oziol 2 1 LBL/NERSC 2 The H DF G roup NERSC A SCR R equirements f or 2 017 January 1 5, 2 014 LBNL 1. Project Description! * m636 r epo * LBL V is B ase P rogram ( Bethel P I) [ PM: N owell] * Conduct f undamental a nd a pplied vis/analyEcs R &D t o address e xascale c hallenges * ExaHDF5 P roject ( Prabhat, Q uincey P Is) [ PM: Nowell] * Scale P arallel I /O, a nd d ata m anagement t echnologies f or current

  15. Parallel heater system for subsurface formations

    DOE Patents [OSTI]

    Harris, Christopher Kelvin (Houston, TX); Karanikas, John Michael (Houston, TX); Nguyen, Scott Vinh (Houston, TX)

    2011-10-25

    A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.

  16. Digitally programmable signal generator and method

    DOE Patents [OSTI]

    Priatko, G.J.; Kaskey, J.A.

    1989-11-14

    Disclosed is a digitally programmable waveform generator for generating completely arbitrary digital or analog waveforms from very low frequencies to frequencies in the gigasample per second range. A memory array with multiple parallel outputs is addressed; then the parallel output data is latched into buffer storage from which it is serially multiplexed out at a data rate many times faster than the access time of the memory array itself. While data is being multiplexed out serially, the memory array is accessed with the next required address and presents its data to the buffer storage before the serial multiplexing of the last group of data is completed, allowing this new data to then be latched into the buffer storage for smooth continuous serial data output. In a preferred implementation, a plurality of these serial data outputs are paralleled to form the input to a digital to analog converter, providing a programmable analog output. 6 figs.

  17. Digitally programmable signal generator and method

    DOE Patents [OSTI]

    Priatko, Gordon J.; Kaskey, Jeffrey A.

    1989-01-01

    A digitally programmable waveform generator for generating completely arbitrary digital or analog waveforms from very low frequencies to frequencies in the gigasample per second range. A memory array with multiple parallel outputs is addressed; then the parallel output data is latched into buffer storage from which it is serially multiplexed out at a data rate many times faster than the access time of the memory array itself. While data is being multiplexed out serially, the memory array is accessed with the next required address and presents its data to the buffer storage before the serial multiplexing of the last group of data is completed, allowing this new data to then be latched into the buffer storage for smooth continuous serial data output. In a preferred implementation, a plurality of these serial data outputs are paralleled to form the input to a digital to analog converter, providing a programmable analog output.

  18. Processing data communications events by awakening threads in parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2016-03-15

    Processing data communications events in a parallel active messaging interface (`PAMI`) of a parallel computer that includes compute nodes that execute a parallel application, with the PAMI including data communications endpoints, and the endpoints are coupled for data communications through the PAMI and through other data communications resources, including determining by an advance function that there are no actionable data communications events pending for its context, placing by the advance function its thread of execution into a wait state, waiting for a subsequent data communications event for the context; responsive to occurrence of a subsequent data communications event for the context, awakening by the thread from the wait state; and processing by the advance function the subsequent data communications event now pending for the context.

  19. Parallel tetrahedral mesh refinement with MOAB.

    SciTech Connect (OSTI)

    Thompson, David C.; Pebay, Philippe Pierre

    2008-12-01

    In this report, we present the novel functionality of parallel tetrahedral mesh refinement which we have implemented in MOAB. This report details work done to implement parallel, edge-based, tetrahedral refinement into MOAB. The theoretical basis for this work is contained in [PT04, PT05, TP06] while information on design, performance, and operation specific to MOAB are contained herein. As MOAB is intended mainly for use in pre-processing and simulation (as opposed to the post-processing bent of previous papers), the primary use case is different: rather than refining elements with non-linear basis functions, the goal is to increase the number of degrees of freedom in some region in order to more accurately represent the solution to some system of equations that cannot be solved analytically. Also, MOAB has a unique mesh representation which impacts the algorithm. This introduction contains a brief review of streaming edge-based tetrahedral refinement. The remainder of the report is broken into three sections: design and implementation, performance, and conclusions. Appendix A contains instructions for end users (simulation authors) on how to employ the refiner.

  20. Switch for serial or parallel communication networks

    DOE Patents [OSTI]

    Crosette, D.B.

    1994-07-19

    A communication switch apparatus and a method for use in a geographically extensive serial, parallel or hybrid communication network linking a multi-processor or parallel processing system has a very low software processing overhead in order to accommodate random burst of high density data. Associated with each processor is a communication switch. A data source and a data destination, a sensor suite or robot for example, may also be associated with a switch. The configuration of the switches in the network are coordinated through a master processor node and depends on the operational phase of the multi-processor network: data acquisition, data processing, and data exchange. The master processor node passes information on the state to be assumed by each switch to the processor node associated with the switch. The processor node then operates a series of multi-state switches internal to each communication switch. The communication switch does not parse and interpret communication protocol and message routing information. During a data acquisition phase, the communication switch couples sensors producing data to the processor node associated with the switch, to a downlink destination on the communications network, or to both. It also may couple an uplink data source to its processor node. During the data exchange phase, the switch couples its processor node or an uplink data source to a downlink destination (which may include a processor node or a robot), or couples an uplink source to its processor node and its processor node to a downlink destination. 9 figs.

  1. Switch for serial or parallel communication networks

    DOE Patents [OSTI]

    Crosette, Dario B.

    1994-01-01

    A communication switch apparatus and a method for use in a geographically extensive serial, parallel or hybrid communication network linking a multi-processor or parallel processing system has a very low software processing overhead in order to accommodate random burst of high density data. Associated with each processor is a communication switch. A data source and a data destination, a sensor suite or robot for example, may also be associated with a switch. The configuration of the switches in the network are coordinated through a master processor node and depends on the operational phase of the multi-processor network: data acquisition, data processing, and data exchange. The master processor node passes information on the state to be assumed by each switch to the processor node associated with the switch. The processor node then operates a series of multi-state switches internal to each communication switch. The communication switch does not parse and interpret communication protocol and message routing information. During a data acquisition phase, the communication switch couples sensors producing data to the processor node associated with the switch, to a downlink destination on the communications network, or to both. It also may couple an uplink data source to its processor node. During the data exchange phase, the switch couples its processor node or an uplink data source to a downlink destination (which may include a processor node or a robot), or couples an uplink source to its processor node and its processor node to a downlink destination.

  2. Fuel dissipater for pressurized fuel cell generators

    DOE Patents [OSTI]

    Basel, Richard A.; King, John E.

    2003-11-04

    An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a pressurized fuel cell generator (10) when the electrical power output of the fuel cell generator is terminated during transient operation, such as a shutdown; where, two electrically resistive elements (two of 28, 53, 54, 55) at least one of which is connected in parallel, in association with contactors (26, 57, 58, 59), a multi-point settable sensor relay (23) and a circuit breaker (24), are automatically connected across the fuel cell generator terminals (21, 22) at two or more contact points, in order to draw current, thereby depleting the fuel inventory in the generator.

  3. Paradyn a parallel nonlinear, explicit, three-dimensional finite-element code for solid and structural mechanics user manual

    SciTech Connect (OSTI)

    Hoover, C G; DeGroot, A J; Sherwood, R J

    2000-06-01

    ParaDyn is a parallel version of the DYNA3D computer program, a three-dimensional explicit finite-element program for analyzing the dynamic response of solids and structures. The ParaDyn program has been used as a production tool for over three years for analyzing problems which range in size from a few tens of thousands of elements to between one-million and ten-million elements. ParaDyn runs on parallel computers provided by the Department of Energy Accelerated Strategic Computing Initiative (ASCI) and the Department of Defense High Performance Computing and Modernization Program. Preprocessing and post-processing software utilities and tools are designed to facilitate the generation of partitioned domains for processors on a massively parallel computer and the visualization of both resultant data and boundary data generated in a parallel simulation. This manual provides a brief overview of the parallel implementation; describes techniques for running the ParaDyn program, tools and utilities; and provides examples of parallel simulations.

  4. PULSE GENERATOR

    DOE Patents [OSTI]

    Roeschke, C.W.

    1957-09-24

    An improvement in pulse generators is described by which there are produced pulses of a duration from about 1 to 10 microseconds with a truly flat top and extremely rapid rise and fall. The pulses are produced by triggering from a separate input or by modifying the current to operate as a free-running pulse generator. In its broad aspect, the disclosed pulse generator comprises a first tube with an anode capacitor and grid circuit which controls the firing; a second tube series connected in the cathode circuit of the first tube such that discharge of the first tube places a voltage across it as the leading edge of the desired pulse; and an integrator circuit from the plate across the grid of the second tube to control the discharge time of the second tube, determining the pulse length.

  5. Microwave generator

    DOE Patents [OSTI]

    Kwan, T.J.T.; Snell, C.M.

    1987-03-31

    A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit there through effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators. 6 figs.

  6. Sub-Second Parallel State Estimation

    SciTech Connect (OSTI)

    Chen, Yousu; Rice, Mark J.; Glaesemann, Kurt R.; Wang, Shaobu; Huang, Zhenyu

    2014-10-31

    This report describes the performance of Pacific Northwest National Laboratory (PNNL) sub-second parallel state estimation (PSE) tool using the utility data from the Bonneville Power Administrative (BPA) and discusses the benefits of the fast computational speed for power system applications. The test data were provided by BPA. They are two-days’ worth of hourly snapshots that include power system data and measurement sets in a commercial tool format. These data are extracted out from the commercial tool box and fed into the PSE tool. With the help of advanced solvers, the PSE tool is able to solve each BPA hourly state estimation problem within one second, which is more than 10 times faster than today’s commercial tool. This improved computational performance can help increase the reliability value of state estimation in many aspects: (1) the shorter the time required for execution of state estimation, the more time remains for operators to take appropriate actions, and/or to apply automatic or manual corrective control actions. This increases the chances of arresting or mitigating the impact of cascading failures; (2) the SE can be executed multiple times within time allowance. Therefore, the robustness of SE can be enhanced by repeating the execution of the SE with adaptive adjustments, including removing bad data and/or adjusting different initial conditions to compute a better estimate within the same time as a traditional state estimator’s single estimate. There are other benefits with the sub-second SE, such as that the PSE results can potentially be used in local and/or wide-area automatic corrective control actions that are currently dependent on raw measurements to minimize the impact of bad measurements, and provides opportunities to enhance the power grid reliability and efficiency. PSE also can enable other advanced tools that rely on SE outputs and could be used to further improve operators’ actions and automated controls to mitigate effects

  7. Optimized data communications in a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A

    2014-10-21

    A parallel computer includes nodes that include a network adapter that couples the node in a point-to-point network and supports communications in opposite directions of each dimension. Optimized communications include: receiving, by a network adapter of a receiving compute node, a packet--from a source direction--that specifies a destination node and deposit hints. Each hint is associated with a direction within which the packet is to be deposited. If a hint indicates the packet to be deposited in the opposite direction: the adapter delivers the packet to an application on the receiving node; forwards the packet to a next node in the opposite direction if the receiving node is not the destination; and forwards the packet to a node in a direction of a subsequent dimension if the hints indicate that the packet is to be deposited in the direction of the subsequent dimension.

  8. Clock Agreement Among Parallel Supercomputer Nodes

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jones, Terry R.; Koenig, Gregory A.

    This dataset presents measurements that quantify the clock synchronization time-agreement characteristics among several high performance computers including the current world's most powerful machine for open science, the U.S. Department of Energy's Titan machine sited at Oak Ridge National Laboratory. These ultra-fast machines derive much of their computational capability from extreme node counts (over 18000 nodes in the case of the Titan machine). Time-agreement is commonly utilized by parallel programming applications and tools, distributed programming application and tools, and system software. Our time-agreement measurements detail the degree of time variance between nodes and how that variance changes over time. The dataset includes empirical measurements and the accompanying spreadsheets.

  9. LAPACK BLAS Parallel BLAS ScaLAPACK

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    LAPACK BLAS Parallel BLAS ScaLAPACK (E.g., MPI, PVM) PBLAS Local Addressing Global Addressing man intro_blas3 man intro_blacs man intro_lapack BLACS Message Passing Primitives man intro_scalapack Basic Lin. Alg. Communication Subprograms 0 1 2 3 0 4 5 0 1 2 1 NB M N MB a a a a a a a a a a a a a a a a a a a a a a a a 11 12 13 14 a a a a a 15 16 17 18 19 a a a a a a a a a 21 22 23 24 25 26 27 28 29 a a a a a a a a a a a a a a a a a a a a a a a a a 31 32 33 34 35 36 37 38 39 41 42 43 44 45 46 47 48

  10. Optimized data communications in a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A.

    2014-08-19

    A parallel computer includes nodes that include a network adapter that couples the node in a point-to-point network and supports communications in opposite directions of each dimension. Optimized communications include: receiving, by a network adapter of a receiving compute node, a packet--from a source direction--that specifies a destination node and deposit hints. Each hint is associated with a direction within which the packet is to be deposited. If a hint indicates the packet to be deposited in the opposite direction: the adapter delivers the packet to an application on the receiving node; forwards the packet to a next node in the opposite direction if the receiving node is not the destination; and forwards the packet to a node in a direction of a subsequent dimension if the hints indicate that the packet is to be deposited in the direction of the subsequent dimension.

  11. Clock Agreement Among Parallel Supercomputer Nodes

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jones, Terry R.; Koenig, Gregory A.

    2014-04-30

    This dataset presents measurements that quantify the clock synchronization time-agreement characteristics among several high performance computers including the current world's most powerful machine for open science, the U.S. Department of Energy's Titan machine sited at Oak Ridge National Laboratory. These ultra-fast machines derive much of their computational capability from extreme node counts (over 18000 nodes in the case of the Titan machine). Time-agreement is commonly utilized by parallel programming applications and tools, distributed programming application and tools, and system software. Our time-agreement measurements detail the degree of time variance between nodes and how that variance changes over time. The dataset includes empirical measurements and the accompanying spreadsheets.

  12. Parallel detecting, spectroscopic ellipsometers/polarimeters

    DOE Patents [OSTI]

    Furtak, Thomas E.

    2002-01-01

    The parallel detecting spectroscopic ellipsometer/polarimeter sensor has no moving parts and operates in real-time for in-situ monitoring of the thin film surface properties of a sample within a processing chamber. It includes a multi-spectral source of radiation for producing a collimated beam of radiation directed towards the surface of the sample through a polarizer. The thus polarized collimated beam of radiation impacts and is reflected from the surface of the sample, thereby changing its polarization state due to the intrinsic material properties of the sample. The light reflected from the sample is separated into four separate polarized filtered beams, each having individual spectral intensities. Data about said four individual spectral intensities is collected within the processing chamber, and is transmitted into one or more spectrometers. The data of all four individual spectral intensities is then analyzed using transformation algorithms, in real-time.

  13. Internode data communications in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.; Miller, Douglas R.; Parker, Jeffrey J.; Ratterman, Joseph D.; Smith, Brian E.

    2013-09-03

    Internode data communications in a parallel computer that includes compute nodes that each include main memory and a messaging unit, the messaging unit including computer memory and coupling compute nodes for data communications, in which, for each compute node at compute node boot time: a messaging unit allocates, in the messaging unit's computer memory, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; receives, prior to initialization of a particular process on the compute node, a data communications message intended for the particular process; and stores the data communications message in the message buffer associated with the particular process. Upon initialization of the particular process, the process establishes a messaging buffer in main memory of the compute node and copies the data communications message from the message buffer of the messaging unit into the message buffer of main memory.

  14. Broadcasting a message in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Faraj, Ahmad A

    2013-04-16

    Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the child nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.

  15. Intranode data communications in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Miller, Douglas R; Ratterman, Joseph D; Smith, Brian E

    2013-07-23

    Intranode data communications in a parallel computer that includes compute nodes configured to execute processes, where the data communications include: allocating, upon initialization of a first process of a compute node, a region of shared memory; establishing, by the first process, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; sending, to a second process on the same compute node, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process; and upon initialization of the second process: retrieving, by the second process, a pointer to the second process's message buffer; and retrieving, by the second process from the second process's message buffer in dependence upon the pointer, the data communications message sent by the first process.

  16. Intranode data communications in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Miller, Douglas R; Ratterman, Joseph D; Smith, Brian E

    2014-01-07

    Intranode data communications in a parallel computer that includes compute nodes configured to execute processes, where the data communications include: allocating, upon initialization of a first process of a computer node, a region of shared memory; establishing, by the first process, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; sending, to a second process on the same compute node, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process; and upon initialization of the second process: retrieving, by the second process, a pointer to the second process's message buffer; and retrieving, by the second process from the second process's message buffer in dependence upon the pointer, the data communications message sent by the first process.

  17. Internode data communications in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Miller, Douglas R; Parker, Jeffrey J; Ratterman, Joseph D; Smith, Brian E

    2014-02-11

    Internode data communications in a parallel computer that includes compute nodes that each include main memory and a messaging unit, the messaging unit including computer memory and coupling compute nodes for data communications, in which, for each compute node at compute node boot time: a messaging unit allocates, in the messaging unit's computer memory, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; receives, prior to initialization of a particular process on the compute node, a data communications message intended for the particular process; and stores the data communications message in the message buffer associated with the particular process. Upon initialization of the particular process, the process establishes a messaging buffer in main memory of the compute node and copies the data communications message from the message buffer of the messaging unit into the message buffer of main memory.

  18. Parallelism of the SANDstorm hash algorithm.

    SciTech Connect (OSTI)

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree

    2009-09-01

    Mainstream cryptographic hashing algorithms are not parallelizable. This limits their speed and they are not able to take advantage of the current trend of being run on multi-core platforms. Being limited in speed limits their usefulness as an authentication mechanism in secure communications. Sandia researchers have created a new cryptographic hashing algorithm, SANDstorm, which was specifically designed to take advantage of multi-core processing and be parallelizable on a wide range of platforms. This report describes a late-start LDRD effort to verify the parallelizability claims of the SANDstorm designers. We have shown, with operating code and bench testing, that the SANDstorm algorithm may be trivially parallelized on a wide range of hardware platforms. Implementations using OpenMP demonstrates a linear speedup with multiple cores. We have also shown significant performance gains with optimized C code and the use of assembly instructions to exploit particular platform capabilities.

  19. Broadcasting a message in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Faraj, Daniel A

    2014-11-18

    Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the child nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.

  20. Link failure detection in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.; Megerian, Mark G.; Smith, Brian E.

    2010-11-09

    Methods, apparatus, and products are disclosed for link failure detection in a parallel computer including compute nodes connected in a rectangular mesh network, each pair of adjacent compute nodes in the rectangular mesh network connected together using a pair of links, that includes: assigning each compute node to either a first group or a second group such that adjacent compute nodes in the rectangular mesh network are assigned to different groups; sending, by each of the compute nodes assigned to the first group, a first test message to each adjacent compute node assigned to the second group; determining, by each of the compute nodes assigned to the second group, whether the first test message was received from each adjacent compute node assigned to the first group; and notifying a user, by each of the compute nodes assigned to the second group, whether the first test message was received.

  1. CS-Studio Scan System Parallelization

    SciTech Connect (OSTI)

    Kasemir, Kay; Pearson, Matthew R

    2015-01-01

    For several years, the Control System Studio (CS-Studio) Scan System has successfully automated the operation of beam lines at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). As it is applied to additional beam lines, we need to support simultaneous adjustments of temperatures or motor positions. While this can be implemented via virtual motors or similar logic inside the Experimental Physics and Industrial Control System (EPICS) Input/Output Controllers (IOCs), doing so requires a priori knowledge of experimenters requirements. By adding support for the parallel control of multiple process variables (PVs) to the Scan System, we can better support ad hoc automation of experiments that benefit from such simultaneous PV adjustments.

  2. Substantially parallel flux uncluttered rotor machines

    DOE Patents [OSTI]

    Hsu, John S.

    2012-12-11

    A permanent magnet-less and brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by polyphase alternating currents. An uncluttered rotor is positioned within the magnetic rotating field and is spaced apart from the stator. An excitation core is spaced apart from the stator and the uncluttered rotor and magnetically couples the uncluttered rotor. The brushless excitation source generates a magnet torque by inducing magnetic poles near an outer peripheral surface of the uncluttered rotor, and the stator currents also generate a reluctance torque by a reaction of the difference between the direct and quadrature magnetic paths of the uncluttered rotor. The system can be used either as a motor or a generator

  3. Scalable Parallel Methods for Analyzing Metagenomics Data at Extreme Scale

    SciTech Connect (OSTI)

    Daily, Jeffrey A.

    2015-05-01

    The field of bioinformatics and computational biology is currently experiencing a data revolution. The exciting prospect of making fundamental biological discoveries is fueling the rapid development and deployment of numerous cost-effective, high-throughput next-generation sequencing technologies. The result is that the DNA and protein sequence repositories are being bombarded with new sequence information. Databases are continuing to report a Moore’s law-like growth trajectory in their database sizes, roughly doubling every 18 months. In what seems to be a paradigm-shift, individual projects are now capable of generating billions of raw sequence data that need to be analyzed in the presence of already annotated sequence information. While it is clear that data-driven methods, such as sequencing homology detection, are becoming the mainstay in the field of computational life sciences, the algorithmic advancements essential for implementing complex data analytics at scale have mostly lagged behind. Sequence homology detection is central to a number of bioinformatics applications including genome sequencing and protein family characterization. Given millions of sequences, the goal is to identify all pairs of sequences that are highly similar (or “homologous”) on the basis of alignment criteria. While there are optimal alignment algorithms to compute pairwise homology, their deployment for large-scale is currently not feasible; instead, heuristic methods are used at the expense of quality. In this dissertation, we present the design and evaluation of a parallel implementation for conducting optimal homology detection on distributed memory supercomputers. Our approach uses a combination of techniques from asynchronous load balancing (viz. work stealing, dynamic task counters), data replication, and exact-matching filters to achieve homology detection at scale. Results for a collection of 2.56M sequences show parallel efficiencies of ~75-100% on up to 8K cores

  4. Methods and apparatus for multi-resolution replication of files in a parallel computing system using semantic information

    DOE Patents [OSTI]

    Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Torres, Aaron

    2015-10-20

    Techniques are provided for storing files in a parallel computing system using different resolutions. A method is provided for storing at least one file generated by a distributed application in a parallel computing system. The file comprises one or more of a complete file and a sub-file. The method comprises the steps of obtaining semantic information related to the file; generating a plurality of replicas of the file with different resolutions based on the semantic information; and storing the file and the plurality of replicas of the file in one or more storage nodes of the parallel computing system. The different resolutions comprise, for example, a variable number of bits and/or a different sub-set of data elements from the file. A plurality of the sub-files can be merged to reproduce the file.

  5. Magnetocumulative generator

    DOE Patents [OSTI]

    Pettibone, J.S.; Wheeler, P.C.

    1981-06-08

    An improved magnetocumulative generator is described that is useful for producing magnetic fields of very high energy content over large spatial volumes. The polar directed pleated magnetocumulative generator has a housing providing a housing chamber with an electrically conducting surface. The chamber forms a coaxial system having a small radius portion and a large radius portion. When a magnetic field is injected into the chamber, from an external source, most of the magnetic flux associated therewith positions itself in the small radius portion. The propagation of an explosive detonation through high-explosive layers disposed adjacent to the housing causes a phased closure of the chamber which sweeps most of the magnetic flux into the large radius portion of the coaxial system. The energy content of the magnetic field is greatly increased by flux stretching as well as by flux compression. The energy enhanced magnetic field is utilized within the housing chamber itself.

  6. PLASMA GENERATOR

    DOE Patents [OSTI]

    Foster, J.S. Jr.

    1958-03-11

    This patent describes apparatus for producing an electricity neutral ionized gas discharge, termed a plasma, substantially free from contamination with neutral gas particles. The plasma generator of the present invention comprises a plasma chamber wherein gas introduced into the chamber is ionized by a radiofrequency source. A magnetic field is used to focus the plasma in line with an exit. This magnetic field cooperates with a differential pressure created across the exit to draw a uniform and uncontaminated plasma from the plasma chamber.

  7. Thermoelectric generator

    DOE Patents [OSTI]

    Pryslak, N.E.

    1974-02-26

    A thermoelectric generator having a rigid coupling or stack'' between the heat source and the hot strap joining the thermoelements is described. The stack includes a member of an insulating material, such as ceramic, for electrically isolating the thermoelements from the heat source, and a pair of members of a ductile material, such as gold, one each on each side of the insulating member, to absorb thermal differential expansion stresses in the stack. (Official Gazette)

  8. Cluster generator

    DOE Patents [OSTI]

    Donchev, Todor I.; Petrov, Ivan G.

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  9. Photon generator

    DOE Patents [OSTI]

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  10. Electric generator

    DOE Patents [OSTI]

    Foster, Jr., John S.; Wilson, James R.; McDonald, Jr., Charles A.

    1983-01-01

    1. In an electrical energy generator, the combination comprising a first elongated annular electrical current conductor having at least one bare surface extending longitudinally and facing radially inwards therein, a second elongated annular electrical current conductor disposed coaxially within said first conductor and having an outer bare surface area extending longitudinally and facing said bare surface of said first conductor, the contiguous coaxial areas of said first and second conductors defining an inductive element, means for applying an electrical current to at least one of said conductors for generating a magnetic field encompassing said inductive element, and explosive charge means disposed concentrically with respect to said conductors including at least the area of said inductive element, said explosive charge means including means disposed to initiate an explosive wave front in said explosive advancing longitudinally along said inductive element, said wave front being effective to progressively deform at least one of said conductors to bring said bare surfaces thereof into electrically conductive contact to progressively reduce the inductance of the inductive element defined by said conductors and transferring explosive energy to said magnetic field effective to generate an electrical potential between undeformed portions of said conductors ahead of said explosive wave front.

  11. Data communications in a parallel active messaging interface of a parallel computer

    SciTech Connect (OSTI)

    Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2014-09-16

    Eager send data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints that specify a client, a context, and a task, including receiving an eager send data communications instruction with transfer data disposed in a send buffer characterized by a read/write send buffer memory address in a read/write virtual address space of the origin endpoint; determining for the send buffer a read-only send buffer memory address in a read-only virtual address space, the read-only virtual address space shared by both the origin endpoint and the target endpoint, with all frames of physical memory mapped to pages of virtual memory in the read-only virtual address space; and communicating by the origin endpoint to the target endpoint an eager send message header that includes the read-only send buffer memory address.

  12. Data communications in a parallel active messaging interface of a parallel computer

    SciTech Connect (OSTI)

    Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2014-09-02

    Eager send data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints that specify a client, a context, and a task, including receiving an eager send data communications instruction with transfer data disposed in a send buffer characterized by a read/write send buffer memory address in a read/write virtual address space of the origin endpoint; determining for the send buffer a read-only send buffer memory address in a read-only virtual address space, the read-only virtual address space shared by both the origin endpoint and the target endpoint, with all frames of physical memory mapped to pages of virtual memory in the read-only virtual address space; and communicating by the origin endpoint to the target endpoint an eager send message header that includes the read-only send buffer memory address.

  13. Data communications for a collective operation in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A

    2013-07-16

    Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and bit masks; receiving in an origin endpoint of the PAMI a collective instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint; constructing a bit mask for the received collective instruction; selecting, from among the associated algorithms and bit masks, a data communications algorithm in dependence upon the constructed bit mask; and executing the collective instruction, transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.

  14. Data communications for a collective operation in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A.

    2015-11-19

    Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and bit masks; receiving in an origin endpoint of the PAMI a collective instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint; constructing a bit mask for the received collective instruction; selecting, from among the associated algorithms and bit masks, a data communications algorithm in dependence upon the constructed bit mask; and executing the collective instruction, transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.

  15. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2015-02-03

    Data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI and through data communications resources, including receiving in an origin endpoint of the PAMI a SEND instruction, the SEND instruction specifying a transmission of transfer data from the origin endpoint to a first target endpoint; transmitting from the origin endpoint to the first target endpoint a Request-To-Send (`RTS`) message advising the first target endpoint of the location and size of the transfer data; assigning by the first target endpoint to each of a plurality of target endpoints separate portions of the transfer data; and receiving by the plurality of target endpoints the transfer data.

  16. Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2013-09-03

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  17. Fencing data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-06-02

    Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task; the compute nodes coupled for data communications through the PAMI and through data communications resources including at least one segment of shared random access memory; including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers through a segment of shared memory; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

  18. Fencing data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-06-30

    Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint comprising a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI and through data communications resources including a deterministic data communications network, including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

  19. Fencing data transfers in a parallel active messaging interface of a parallel computer

    SciTech Connect (OSTI)

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-08-11

    Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint comprising a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI and through data communications resources including a deterministic data communications network, including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

  20. Fencing data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-06-09

    Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task; the compute nodes coupled for data communications through the PAMI and through data communications resources including at least one segment of shared random access memory; including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers through a segment of shared memory; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

  1. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-11-18

    Data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI and through data communications resources, including receiving in an origin endpoint of the PAMI a SEND instruction, the SEND instruction specifying a transmission of transfer data from the origin endpoint to a first target endpoint; transmitting from the origin endpoint to the first target endpoint a Request-To-Send (`RTS`) message advising the first target endpoint of the location and size of the transfer data; assigning by the first target endpoint to each of a plurality of target endpoints separate portions of the transfer data; and receiving by the plurality of target endpoints the transfer data.

  2. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Davis, Kristan D.; Faraj, Daniel A.

    2014-07-22

    Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and ranges of message sizes so that each algorithm is associated with a separate range of message sizes; receiving in an origin endpoint of the PAMI a data communications instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint, the data communications message characterized by a message size; selecting, from among the associated algorithms and ranges, a data communications algorithm in dependence upon the message size; and transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.

  3. Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A; Mamidala, Amith R

    2014-02-11

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  4. Data communications in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Davis, Kristan D; Faraj, Daniel A

    2013-07-09

    Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and ranges of message sizes so that each algorithm is associated with a separate range of message sizes; receiving in an origin endpoint of the PAMI a data communications instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint, the data communications message characterized by a message size; selecting, from among the associated algorithms and ranges, a data communications algorithm in dependence upon the message size; and transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.

  5. The Swift Parallel Scripting Language for ALCF Systems | Argonne Leadership

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computing Facility Projects bgclang Compiler Cobalt Scheduler GLEAN Petrel Swift The Swift Parallel Scripting Language for ALCF Systems Swift is an implicitly parallel functional language that makes it easier to script higher-level applications or workflows composed from serial or parallel programs. Recently made available across ALCF systems, it has been used to script application workflows in a broad range of diverse disciplines from protein structure prediction to modeling global

  6. DGDFT: A massively parallel method for large scale density functional theory calculations

    SciTech Connect (OSTI)

    Hu, Wei Yang, Chao; Lin, Lin

    2015-09-28

    We describe a massively parallel implementation of the recently developed discontinuous Galerkin density functional theory (DGDFT) method, for efficient large-scale Kohn-Sham DFT based electronic structure calculations. The DGDFT method uses adaptive local basis (ALB) functions generated on-the-fly during the self-consistent field iteration to represent the solution to the Kohn-Sham equations. The use of the ALB set provides a systematic way to improve the accuracy of the approximation. By using the pole expansion and selected inversion technique to compute electron density, energy, and atomic forces, we can make the computational complexity of DGDFT scale at most quadratically with respect to the number of electrons for both insulating and metallic systems. We show that for the two-dimensional (2D) phosphorene systems studied here, using 37 basis functions per atom allows us to reach an accuracy level of 1.3 × 10{sup −4} Hartree/atom in terms of the error of energy and 6.2 × 10{sup −4} Hartree/bohr in terms of the error of atomic force, respectively. DGDFT can achieve 80% parallel efficiency on 128,000 high performance computing cores when it is used to study the electronic structure of 2D phosphorene systems with 3500-14 000 atoms. This high parallel efficiency results from a two-level parallelization scheme that we will describe in detail.

  7. Using ARM data to correct plane-parallel satellite retrievals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using ARM data to correct plane-parallel satellite retrievals of cloud properties Dong, Xiquan University of North Dakota Minnis, Patrick NASA Langley Research Center Xi, Baike...

  8. CPIC: A Parallel Electrostatic Particle-In-Cell Code (Conference...

    Office of Scientific and Technical Information (OSTI)

    Electrostatic Particle-In-Cell Code Citation Details In-Document Search Title: CPIC: A Parallel Electrostatic Particle-In-Cell Code Authors: Meierbachtol, Collin S. 1 ; Delzanno, ...

  9. PFLOTRAN User Manual: A Massively Parallel Reactive Flow and...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: PFLOTRAN User Manual: A Massively Parallel Reactive Flow and Transport Model for Describing Surface and Subsurface Processes Citation Details In-Document Search...

  10. PFLOTRAN User Manual: A Massively Parallel Reactive Flow and...

    Office of Scientific and Technical Information (OSTI)

    PFLOTRAN User Manual: A Massively Parallel Reactive Flow and Transport Model for Describing Surface and Subsurface Processes Lichtner, Peter OFM Research; Karra, Satish Los...

  11. Parallel ptychographic reconstruction (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Parallel ptychographic reconstruction ... GrantContract Number: FC02-06ER25777 Type: Published Article Journal Name: Optics Express ...

  12. Massively Parallel LES of Azimuthal Thermo-Acoustic Instabilities...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Massively Parallel LES of Azimuthal Thermo-Acoustic Instabilities in Annular Gas Turbines Authors: Wolf, P., Staffelbach, G., Roux, A., Gicquel, L., Poinsot, T., Moureau, V. ...

  13. A set of parallel, implicit methods for a reconstructed discontinuous...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: A set of parallel, implicit methods for a reconstructed discontinuous Galerkin method for compressible flows on 3D hybrid grids Citation Details In-Document Search...

  14. A Comprehensive Look at High Performance Parallel I/O

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Comprehensive Look at High Performance Parallel I/O A Comprehensive Look at High Performance Parallel I/O Book Signing @ SC14! Nov. 18, 5 p.m. in Booth 1939 November 10, 2014 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov HighPerf Parallel IO In the 1990s, high performance computing (HPC) made a dramatic transition to massively parallel processors. As this model solidified over the next 20 years, supercomputing performance increased from gigaflops-billions of calculations per second-to

  15. Massively Parallel Models of the Human Circulatory System (Conference...

    Office of Scientific and Technical Information (OSTI)

    Massively Parallel Models of the Human Circulatory System Citation Details In-Document ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 59 ...

  16. A set of parallel, implicit methods for a reconstructed discontinuous...

    Office of Scientific and Technical Information (OSTI)

    Furthermore, an SPMD (single program, multiple data) programming paradigm based on MPI is proposed to achieve parallelism. The numerical results on complex geometries...

  17. A garbage collection algorithm for shared memory parallel processors

    SciTech Connect (OSTI)

    Crammond, J. )

    1988-12-01

    This paper describes a technique for adapting the Morris sliding garbage collection algorithm to execute on parallel machines with shared memory. The algorithm is described within the framework of an implementation of the parallel logic language Parlog. However, the algorithm is a general one and can easily be adapted to parallel Prolog systems and to other languages. The performance of the algorithm executing a few simple Parlog benchmarks is analyzed. Finally, it is shown how the technique for parallelizing the sequential algorithm can be adapted for a semi-space copying algorithm.

  18. Mesoscale Simulations of Particulate Flows with Parallel Distributed...

    Office of Scientific and Technical Information (OSTI)

    Title: Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique Fluid particulate flows are common phenomena in nature and industry. ...

  19. Parallel performance optimizations on unstructured mesh-based simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sarje, Abhinav; Song, Sukhyun; Jacobsen, Douglas; Huck, Kevin; Hollingsworth, Jeffrey; Malony, Allen; Williams, Samuel; Oliker, Leonid

    2015-06-01

    This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intranode data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cache efficiency, as well as communication reduction approaches.more » We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.« less

  20. Portable, parallel, reusable Krylov space codes

    SciTech Connect (OSTI)

    Smith, B.; Gropp, W.

    1994-12-31

    Krylov space accelerators are an important component of many algorithms for the iterative solution of linear systems. Each Krylov space method has it`s own particular advantages and disadvantages, therefore it is desirable to have a variety of them available all with an identical, easy to use, interface. A common complaint application programmers have with available software libraries for the iterative solution of linear systems is that they require the programmer to use the data structures provided by the library. The library is not able to work with the data structures of the application code. Hence, application programmers find themselves constantly recoding the Krlov space algorithms. The Krylov space package (KSP) is a data-structure-neutral implementation of a variety of Krylov space methods including preconditioned conjugate gradient, GMRES, BiCG-Stab, transpose free QMR and CGS. Unlike all other software libraries for linear systems that the authors are aware of, KSP will work with any application codes data structures, in Fortran or C. Due to it`s data-structure-neutral design KSP runs unchanged on both sequential and parallel machines. KSP has been tested on workstations, the Intel i860 and Paragon, Thinking Machines CM-5 and the IBM SP1.

  1. Multi-petascale highly efficient parallel supercomputer

    DOE Patents [OSTI]

    Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.; Blumrich, Matthias A.; Boyle, Peter; Brunheroto, Jose R.; Chen, Dong; Cher, Chen -Yong; Chiu, George L.; Christ, Norman; Coteus, Paul W.; Davis, Kristan D.; Dozsa, Gabor J.; Eichenberger, Alexandre E.; Eisley, Noel A.; Ellavsky, Matthew R.; Evans, Kahn C.; Fleischer, Bruce M.; Fox, Thomas W.; Gara, Alan; Giampapa, Mark E.; Gooding, Thomas M.; Gschwind, Michael K.; Gunnels, John A.; Hall, Shawn A.; Haring, Rudolf A.; Heidelberger, Philip; Inglett, Todd A.; Knudson, Brant L.; Kopcsay, Gerard V.; Kumar, Sameer; Mamidala, Amith R.; Marcella, James A.; Megerian, Mark G.; Miller, Douglas R.; Miller, Samuel J.; Muff, Adam J.; Mundy, Michael B.; O'Brien, John K.; O'Brien, Kathryn M.; Ohmacht, Martin; Parker, Jeffrey J.; Poole, Ruth J.; Ratterman, Joseph D.; Salapura, Valentina; Satterfield, David L.; Senger, Robert M.; Smith, Brian; Steinmacher-Burow, Burkhard; Stockdell, William M.; Stunkel, Craig B.; Sugavanam, Krishnan; Sugawara, Yutaka; Takken, Todd E.; Trager, Barry M.; Van Oosten, James L.; Wait, Charles D.; Walkup, Robert E.; Watson, Alfred T.; Wisniewski, Robert W.; Wu, Peng

    2015-07-14

    A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaOPS-scale computing, at decreased cost, power and footprint, and that allows for a maximum packaging density of processing nodes from an interconnect point of view. The Supercomputer exploits technological advances in VLSI that enables a computing model where many processors can be integrated into a single Application Specific Integrated Circuit (ASIC). Each ASIC computing node comprises a system-on-chip ASIC utilizing four or more processors integrated into one die, with each having full access to all system resources and enabling adaptive partitioning of the processors to functions such as compute or messaging I/O on an application by application basis, and preferably, enable adaptive partitioning of functions in accordance with various algorithmic phases within an application, or if I/O or other processors are underutilized, then can participate in computation or communication nodes are interconnected by a five dimensional torus network with DMA that optimally maximize the throughput of packet communications between nodes and minimize latency.

  2. Berkeley Unified Parallel C (UPC) Runtime Library

    Energy Science and Technology Software Center (OSTI)

    2003-03-31

    This software comprises a portable, open source implementation of a runtime library to support applications written in the Unified Parallel C (UPC) language. This library implements the UPC-specific functionality, including shared memory allocation and locks. The network-dependent functionality is implemented as a thin wrapper around a separate library implementing the GASNet (Global-Address Space Networking) specification. For true shared memory machines. GASNet is bypassed in favor of direct memory operations and local synchronization mechanisms. The Berkeleymore » UPC Runtime Library is currently the only implementation of the "Berkeley UPC Runtime Specification", and thus the only runtme library usable with the Berkeley UPC Compiler. Also, it is the only UPC runtime known to the author to provide two shared pointer representations: one for arbitrary blocksizes and one to optimize for the common cases of phaseless and blocksize=1. For distributed memory environments a library implementing the GASNet (Global-Address Space Networking) specification is required for communication. While no specialized hardware is required, a high-speed interconnet supported by the GASNet implementation is suggested for preformance. If no supported high-speed interconnect is available. GASNet can run over MPI. An external library is reqired for certain local memory allocation operations. A well defined interface allows for multiple implementations of this library, but at present the "umalloc" library from LBNL is the only compatible implementation.« less

  3. Flexible Language Constructs for Large Parallel Programs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rosing, Matt; Schnabel, Robert

    1994-01-01

    The goal of the research described in this article is to develop flexible language constructs for writing large data parallel numerical programs for distributed memory (multiple instruction multiple data [MIMD]) multiprocessors. Previously, several models have been developed to support synchronization and communication. Models for global synchronization include single instruction multiple data (SIMD), single program multiple data (SPMD), and sequential programs annotated with data distribution statements. The two primary models for communication include implicit communication based on shared memory and explicit communication based on messages. None of these models by themselves seem sufficient to permit the natural and efficient expression ofmore » the variety of algorithms that occur in large scientific computations. In this article, we give an overview of a new language that combines many of these programming models in a clean manner. This is done in a modular fashion such that different models can be combined to support large programs. Within a module, the selection of a model depends on the algorithm and its efficiency requirements. In this article, we give an overview of the language and discuss some of the critical implementation details.« less

  4. Monthly Generation System Peak (pbl/generation)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generation > Generation Hydro Power Wind Power Monthly GSP BPA White Book Dry Year Tools Firstgov Monthly Generation System Peak (GSP) This site is no longer maintained. Page last...

  5. Microelectromechanical power generator and vibration sensor

    DOE Patents [OSTI]

    Roesler, Alexander W.; Christenson, Todd R.

    2006-11-28

    A microelectromechanical (MEM) apparatus is disclosed which can be used to generate electrical power in response to an external source of vibrations, or to sense the vibrations and generate an electrical output voltage in response thereto. The MEM apparatus utilizes a meandering electrical pickup located near a shuttle which holds a plurality of permanent magnets. Upon movement of the shuttle in response to vibrations coupled thereto, the permanent magnets move in a direction substantially parallel to the meandering electrical pickup, and this generates a voltage across the meandering electrical pickup. The MEM apparatus can be fabricated by LIGA or micromachining.

  6. Magnetocumulative generator

    DOE Patents [OSTI]

    Pettibone, Joseph S.; Wheeler, Paul C.

    1983-01-01

    An improved magnetocumulative generator is described that is useful for producing magnetic fields of very high energy content over large spatial volumes. The polar directed pleated magnetocumulative generator has a housing (100, 101, 102, 103, 104, 105) providing a housing chamber (106) with an electrically conducting surface. The chamber (106) forms a coaxial system having a small radius portion and a large radius portion. When a magnetic field is injected into the chamber (106), from an external source, most of the magnetic flux associated therewith positions itself in the small radius portion. The propagation of an explosive detonation through high-explosive layers (107, 108) disposed adjacent to the housing causes a phased closure of the chamber (106) which sweeps most of the magnetic flux into the large radius portion of the coaxial system. The energy content of the magnetic field is greatly increased by flux stretching as well as by flux compression. The energy enhanced magnetic field is utilized within the housing chamber itself.

  7. Current parallel I/O limitations to scalable data analysis.

    SciTech Connect (OSTI)

    Mascarenhas, Ajith Arthur; Pebay, Philippe Pierre

    2011-07-01

    This report describes the limitations to parallel scalability which we have encountered when applying our otherwise optimally scalable parallel statistical analysis tool kit to large data sets distributed across the parallel file system of the current premier DOE computational facility. This report describes our study to evaluate the effect of parallel I/O on the overall scalability of a parallel data analysis pipeline using our scalable parallel statistics tool kit [PTBM11]. In this goal, we tested it using the Jaguar-pf DOE/ORNL peta-scale platform on a large combustion simulation data under a variety of process counts and domain decompositions scenarios. In this report we have recalled the foundations of the parallel statistical analysis tool kit which we have designed and implemented, with the specific double intent of reproducing typical data analysis workflows, and achieving optimal design for scalable parallel implementations. We have briefly reviewed those earlier results and publications which allow us to conclude that we have achieved both goals. However, in this report we have further established that, when used in conjuction with a state-of-the-art parallel I/O system, as can be found on the premier DOE peta-scale platform, the scaling properties of the overall analysis pipeline comprising parallel data access routines degrade rapidly. This finding is problematic and must be addressed if peta-scale data analysis is to be made scalable, or even possible. In order to attempt to address these parallel I/O limitations, we will investigate the use the Adaptable IO System (ADIOS) [LZL+10] to improve I/O performance, while maintaining flexibility for a variety of IO options, such MPI IO, POSIX IO. This system is developed at ORNL and other collaborating institutions, and is being tested extensively on Jaguar-pf. Simulation code being developed on these systems will also use ADIOS to output the data thereby making it easier for other systems, such as ours, to

  8. Parallel community climate model: Description and user`s guide

    SciTech Connect (OSTI)

    Drake, J.B.; Flanery, R.E.; Semeraro, B.D.; Worley, P.H.

    1996-07-15

    This report gives an overview of a parallel version of the NCAR Community Climate Model, CCM2, implemented for MIMD massively parallel computers using a message-passing programming paradigm. The parallel implementation was developed on an Intel iPSC/860 with 128 processors and on the Intel Delta with 512 processors, and the initial target platform for the production version of the code is the Intel Paragon with 2048 processors. Because the implementation uses a standard, portable message-passing libraries, the code has been easily ported to other multiprocessors supporting a message-passing programming paradigm. The parallelization strategy used is to decompose the problem domain into geographical patches and assign each processor the computation associated with a distinct subset of the patches. With this decomposition, the physics calculations involve only grid points and data local to a processor and are performed in parallel. Using parallel algorithms developed for the semi-Lagrangian transport, the fast Fourier transform and the Legendre transform, both physics and dynamics are computed in parallel with minimal data movement and modest change to the original CCM2 source code. Sequential or parallel history tapes are written and input files (in history tape format) are read sequentially by the parallel code to promote compatibility with production use of the model on other computer systems. A validation exercise has been performed with the parallel code and is detailed along with some performance numbers on the Intel Paragon and the IBM SP2. A discussion of reproducibility of results is included. A user`s guide for the PCCM2 version 2.1 on the various parallel machines completes the report. Procedures for compilation, setup and execution are given. A discussion of code internals is included for those who may wish to modify and use the program in their own research.

  9. Endpoint-based parallel data processing with non-blocking collective instructions in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Cernohous, Bob R; Ratterman, Joseph D; Smith, Brian E

    2014-11-18

    Methods, apparatuses, and computer program products for endpoint-based parallel data processing with non-blocking collective instructions in a parallel active messaging interface (`PAMI`) of a parallel computer are provided. Embodiments include establishing by a parallel application a data communications geometry, the geometry specifying a set of endpoints that are used in collective operations of the PAMI, including associating with the geometry a list of collective algorithms valid for use with the endpoints of the geometry. Embodiments also include registering in each endpoint in the geometry a dispatch callback function for a collective operation and executing without blocking, through a single one of the endpoints in the geometry, an instruction for the collective operation.

  10. Parallel In Situ Indexing for Data-intensive Computing

    SciTech Connect (OSTI)

    Kim, Jinoh; Abbasi, Hasan; Chacon, Luis; Docan, Ciprian; Klasky, Scott; Liu, Qing; Podhorszki, Norbert; Shoshani, Arie; Wu, Kesheng

    2011-09-09

    As computing power increases exponentially, vast amount of data is created by many scientific re- search activities. However, the bandwidth for storing the data to disks and reading the data from disks has been improving at a much slower pace. These two trends produce an ever-widening data access gap. Our work brings together two distinct technologies to address this data access issue: indexing and in situ processing. From decades of database research literature, we know that indexing is an effective way to address the data access issue, particularly for accessing relatively small fraction of data records. As data sets increase in sizes, more and more analysts need to use selective data access, which makes indexing an even more important for improving data access. The challenge is that most implementations of in- dexing technology are embedded in large database management systems (DBMS), but most scientific datasets are not managed by any DBMS. In this work, we choose to include indexes with the scientific data instead of requiring the data to be loaded into a DBMS. We use compressed bitmap indexes from the FastBit software which are known to be highly effective for query-intensive workloads common to scientific data analysis. To use the indexes, we need to build them first. The index building procedure needs to access the whole data set and may also require a significant amount of compute time. In this work, we adapt the in situ processing technology to generate the indexes, thus removing the need of read- ing data from disks and to build indexes in parallel. The in situ data processing system used is ADIOS, a middleware for high-performance I/O. Our experimental results show that the indexes can improve the data access time up to 200 times depending on the fraction of data selected, and using in situ data processing system can effectively reduce the time needed to create the indexes, up to 10 times with our in situ technique when using identical parallel settings.

  11. PLASMA GENERATOR

    DOE Patents [OSTI]

    Wilcox, J.M.; Baker, W.R.

    1963-09-17

    This invention is a magnetohydrodynamic device for generating a highly ionized ion-electron plasma at a region remote from electrodes and structural members, thus avoiding contamination of the plasma. The apparatus utilizes a closed, gas-filled, cylindrical housing in which an axially directed magnetic field is provided. At one end of the housing, a short cylindrical electrode is disposed coaxially around a short axial inner electrode. A radial electrical discharge is caused to occur between the inner and outer electrodes, creating a rotating hydromagnetic ionization wave that propagates aiong the magnetic field lines toward the opposite end of the housing. A shorting switch connected between the electrodes prevents the wave from striking the opposite end of the housing. (AEC)

  12. Triboelectric generator

    DOE Patents [OSTI]

    Wang, Zhong L; Fan, Fengru; Lin, Long; Zhu, Guang; Pan, Caofeng; Zhou, Yusheng

    2015-11-03

    A generator includes a thin first contact charging layer and a thin second contact charging layer. The thin first contact charging layer includes a first material that has a first rating on a triboelectric series. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer includes a second material that has a second rating on a triboelectric series that is more negative than the first rating. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer is disposed adjacent to the first contact charging layer so that the second side of the second contact charging layer is in contact with the second side of the first contact charging layer.

  13. Parallel 3-D method of characteristics in MPACT

    SciTech Connect (OSTI)

    Kochunas, B.; Dovvnar, T. J.; Liu, Z.

    2013-07-01

    A new parallel 3-D MOC kernel has been developed and implemented in MPACT which makes use of the modular ray tracing technique to reduce computational requirements and to facilitate parallel decomposition. The parallel model makes use of both distributed and shared memory parallelism which are implemented with the MPI and OpenMP standards, respectively. The kernel is capable of parallel decomposition of problems in space, angle, and by characteristic rays up to 0(104) processors. Initial verification of the parallel 3-D MOC kernel was performed using the Takeda 3-D transport benchmark problems. The eigenvalues computed by MPACT are within the statistical uncertainty of the benchmark reference and agree well with the averages of other participants. The MPACT k{sub eff} differs from the benchmark results for rodded and un-rodded cases by 11 and -40 pcm, respectively. The calculations were performed for various numbers of processors and parallel decompositions up to 15625 processors; all producing the same result at convergence. The parallel efficiency of the worst case was 60%, while very good efficiency (>95%) was observed for cases using 500 processors. The overall run time for the 500 processor case was 231 seconds and 19 seconds for the case with 15625 processors. Ongoing work is focused on developing theoretical performance models and the implementation of acceleration techniques to minimize the number of iterations to converge. (authors)

  14. Formation of electron kappa distributions due to interactions with parallel propagating whistler waves

    SciTech Connect (OSTI)

    Tao, X. Lu, Q.; Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026

    2014-02-15

    In space plasmas, charged particles are frequently observed to possess a high-energy tail, which is often modeled by a kappa-type distribution function. In this work, the formation of the electron kappa distribution in generation of parallel propagating whistler waves is investigated using fully nonlinear particle-in-cell (PIC) simulations. A previous research concluded that the bi-Maxwellian character of electron distributions is preserved in PIC simulations. We now demonstrate that for interactions between electrons and parallel propagating whistler waves, a non-Maxwellian high-energy tail can be formed, and a kappa distribution can be used to fit the electron distribution in time-asymptotic limit. The ?-parameter is found to decrease with increasing initial temperature anisotropy or decreasing ratio of electron plasma frequency to cyclotron frequency. The results might be helpful to understanding the origin of electron kappa distributions observed in space plasmas.

  15. Parallel 3D Finite Element Particle-in-Cell Simulations with Pic3P

    SciTech Connect (OSTI)

    Candel, A.; Kabel, A.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; Ko, K.; Ben-Zvi, I.; Kewisch, J.; /Brookhaven

    2009-06-19

    SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic Particle-In-Cell code Pic3P. Designed for simulations of beam-cavity interactions dominated by space charge effects, Pic3P solves the complete set of Maxwell-Lorentz equations self-consistently and includes space-charge, retardation and boundary effects from first principles. Higher-order Finite Element methods with adaptive refinement on conformal unstructured meshes lead to highly efficient use of computational resources. Massively parallel processing with dynamic load balancing enables large-scale modeling of photoinjectors with unprecedented accuracy, aiding the design and operation of next-generation accelerator facilities. Applications include the LCLS RF gun and the BNL polarized SRF gun.

  16. Analysis and selection of optimal function implementations in massively parallel computer

    DOE Patents [OSTI]

    Archer, Charles Jens; Peters, Amanda; Ratterman, Joseph D.

    2011-05-31

    An apparatus, program product and method optimize the operation of a parallel computer system by, in part, collecting performance data for a set of implementations of a function capable of being executed on the parallel computer system based upon the execution of the set of implementations under varying input parameters in a plurality of input dimensions. The collected performance data may be used to generate selection program code that is configured to call selected implementations of the function in response to a call to the function under varying input parameters. The collected performance data may be used to perform more detailed analysis to ascertain the comparative performance of the set of implementations of the function under the varying input parameters.

  17. SWAMP+: multiple subsequence alignment using associative massive parallelism

    SciTech Connect (OSTI)

    Steinfadt, Shannon Irene [Los Alamos National Laboratory; Baker, Johnnie W [KENT STATE UNIV.

    2010-10-18

    A new parallel algorithm SWAMP+ incorporates the Smith-Waterman sequence alignment on an associative parallel model known as ASC. It is a highly sensitive parallel approach that expands traditional pairwise sequence alignment. This is the first parallel algorithm to provide multiple non-overlapping, non-intersecting subsequence alignments with the accuracy of Smith-Waterman. The efficient algorithm provides multiple alignments similar to BLAST while creating a better workflow for the end users. The parallel portions of the code run in O(m+n) time using m processors. When m = n, the algorithmic analysis becomes O(n) with a coefficient of two, yielding a linear speedup. Implementation of the algorithm on the SIMD ClearSpeed CSX620 confirms this theoretical linear speedup with real timings.

  18. Parallel architecture for real-time simulation. Master's thesis

    SciTech Connect (OSTI)

    Cockrell, C.D.

    1989-01-01

    This thesis is concerned with the development of a very fast and highly efficient parallel computer architecture for real-time simulation of continuous systems. Currently, several parallel processing systems exist that may be capable of executing a complex simulation in real-time. These systems are examined and the pros and cons of each system discussed. The thesis then introduced a custom-designed parallel architecture based upon The University of Alabama's OPERA architecture. Each component of this system is discussed and rationale presented for its selection. The problem selected, real-time simulation of the Space Shuttle Main Engine for the test and evaluation of the proposed architecture, is explored, identifying the areas where parallelism can be exploited and parallel processing applied. Results from the test and evaluation phase are presented and compared with the results of the same problem that has been processed on a uniprocessor system.

  19. Broadcasting collective operation contributions throughout a parallel computer

    DOE Patents [OSTI]

    Faraj, Ahmad

    2012-02-21

    Methods, systems, and products are disclosed for broadcasting collective operation contributions throughout a parallel computer. The parallel computer includes a plurality of compute nodes connected together through a data communications network. Each compute node has a plurality of processors for use in collective parallel operations on the parallel computer. Broadcasting collective operation contributions throughout a parallel computer according to embodiments of the present invention includes: transmitting, by each processor on each compute node, that processor's collective operation contribution to the other processors on that compute node using intra-node communications; and transmitting on a designated network link, by each processor on each compute node according to a serial processor transmission sequence, that processor's collective operation contribution to the other processors on the other compute nodes using inter-node communications.

  20. Characterizing and Mitigating Work Time Inflation in Task Parallel Programs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olivier, Stephen L.; de Supinski, Bronis R.; Schulz, Martin; Prins, Jan F.

    2013-01-01

    Task parallelism raises the level of abstraction in shared memory parallel programming to simplify the development of complex applications. However, task parallel applications can exhibit poor performance due to thread idleness, scheduling overheads, and work time inflation – additional time spent by threads in a multithreaded computation beyond the time required to perform the same work in a sequential computation. We identify the contributions of each factor to lost efficiency in various task parallel OpenMP applications and diagnose the causes of work time inflation in those applications. Increased data access latency can cause significant work time inflation in NUMAmore » systems. Our locality framework for task parallel OpenMP programs mitigates this cause of work time inflation. Our extensions to the Qthreads library demonstrate that locality-aware scheduling can improve performance up to 3X compared to the Intel OpenMP task scheduler.« less

  1. Wakefield Computations for the CLIC PETS using the Parallel Finite Element Time-Domain Code T3P

    SciTech Connect (OSTI)

    Candel, A; Kabel, A.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; Ko, K.; Syratchev, I.; /CERN

    2009-06-19

    In recent years, SLAC's Advanced Computations Department (ACD) has developed the high-performance parallel 3D electromagnetic time-domain code, T3P, for simulations of wakefields and transients in complex accelerator structures. T3P is based on advanced higher-order Finite Element methods on unstructured grids with quadratic surface approximation. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with unprecedented accuracy, aiding the design of the next generation of accelerator facilities. Applications to the Compact Linear Collider (CLIC) Power Extraction and Transfer Structure (PETS) are presented.

  2. Eighth SIAM conference on parallel processing for scientific computing: Final program and abstracts

    SciTech Connect (OSTI)

    1997-12-31

    This SIAM conference is the premier forum for developments in parallel numerical algorithms, a field that has seen very lively and fruitful developments over the past decade, and whose health is still robust. Themes for this conference were: combinatorial optimization; data-parallel languages; large-scale parallel applications; message-passing; molecular modeling; parallel I/O; parallel libraries; parallel software tools; parallel compilers; particle simulations; problem-solving environments; and sparse matrix computations.

  3. Xyce Parallel Electronic Simulator : users' guide, version 4.1.

    SciTech Connect (OSTI)

    Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.; Santarelli, Keith R.; Fixel, Deborah A.; Coffey, Todd Stirling; Russo, Thomas V.; Schiek, Richard Louis; Keiter, Eric Richard; Pawlowski, Roger Patrick

    2009-02-01

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only). (4) Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing parallel implementation - which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The development of Xyce provides a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms) research and development can be performed. As a result, Xyce is a unique electrical

  4. Xyce parallel electronic simulator : users' guide. Version 5.1.

    SciTech Connect (OSTI)

    Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.; Santarelli, Keith R.; Fixel, Deborah A.; Coffey, Todd Stirling; Russo, Thomas V.; Schiek, Richard Louis; Keiter, Eric Richard; Pawlowski, Roger Patrick

    2009-11-01

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only). (4) Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing parallel implementation - which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The development of Xyce provides a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms) research and development can be performed. As a result, Xyce is a unique electrical

  5. Methods and apparatus for capture and storage of semantic information with sub-files in a parallel computing system

    DOE Patents [OSTI]

    Faibish, Sorin; Bent, John M; Tzelnic, Percy; Grider, Gary; Torres, Aaron

    2015-02-03

    Techniques are provided for storing files in a parallel computing system using sub-files with semantically meaningful boundaries. A method is provided for storing at least one file generated by a distributed application in a parallel computing system. The file comprises one or more of a complete file and a plurality of sub-files. The method comprises the steps of obtaining a user specification of semantic information related to the file; providing the semantic information as a data structure description to a data formatting library write function; and storing the semantic information related to the file with one or more of the sub-files in one or more storage nodes of the parallel computing system. The semantic information provides a description of data in the file. The sub-files can be replicated based on semantically meaningful boundaries.

  6. TECA: A Parallel Toolkit for Extreme Climate Analysis

    SciTech Connect (OSTI)

    Prabhat, Mr; Ruebel, Oliver; Byna, Surendra; Wu, Kesheng; Li, Fuyu; Wehner, Michael; Bethel, E. Wes

    2012-03-12

    We present TECA, a parallel toolkit for detecting extreme events in large climate datasets. Modern climate datasets expose parallelism across a number of dimensions: spatial locations, timesteps and ensemble members. We design TECA to exploit these modes of parallelism and demonstrate a prototype implementation for detecting and tracking three classes of extreme events: tropical cyclones, extra-tropical cyclones and atmospheric rivers. We process a modern TB-sized CAM5 simulation dataset with TECA, and demonstrate good runtime performance for the three case studies.

  7. Nemesis I: Parallel Enhancements to ExodusII

    Energy Science and Technology Software Center (OSTI)

    2006-03-28

    NEMESIS I is an enhancement to the EXODUS II finite element database model used to store and retrieve data for unstructured parallel finite element analyses. NEMESIS I adds data structures which facilitate the partitioning of a scalar (standard serial) EXODUS II file onto parallel disk systems found on many parallel computers. Since the NEMESIS I application programming interface (APl)can be used to append information to an existing EXODUS II files can be used on filesmore » which contain NEMESIS I information. The NEMESIS I information is written and read via C or C++ callable functions which compromise the NEMESIS I API.« less

  8. pcircle - A Suite of Scalable Parallel File System Tools

    SciTech Connect (OSTI)

    WANG, FEIYI

    2015-10-01

    Most of the software related to file system are written for conventional local file system, they are serialized and can't take advantage of the benefit of a large scale parallel file system. "pcircle" software builds on top of ubiquitous MPI in cluster computing environment and "work-stealing" pattern to provide a scalable, high-performance suite of file system tools. In particular - it implemented parallel data copy and parallel data checksumming, with advanced features such as async progress report, checkpoint and restart, as well as integrity checking.

  9. Iterative Schemes for Time Parallelization with Application to Reservoir Simulation

    SciTech Connect (OSTI)

    Garrido, I; Fladmark, G E; Espedal, M S; Lee, B

    2005-04-18

    Parallel methods are usually not applied to the time domain because of the inherit sequentialness of time evolution. But for many evolutionary problems, computer simulation can benefit substantially from time parallelization methods. In this paper, they present several such algorithms that actually exploit the sequential nature of time evolution through a predictor-corrector procedure. This sequentialness ensures convergence of a parallel predictor-corrector scheme within a fixed number of iterations. The performance of these novel algorithms, which are derived from the classical alternating Schwarz method, are illustrated through several numerical examples using the reservoir simulator Athena.

  10. A Framework for Parallel Nonlinear Optimization by Partitioning Localized Constraints

    SciTech Connect (OSTI)

    Xu, You; Chen, Yixin

    2008-06-28

    We present a novel parallel framework for solving large-scale continuous nonlinear optimization problems based on constraint partitioning. The framework distributes constraints and variables to parallel processors and uses an existing solver to handle the partitioned subproblems. In contrast to most previous decomposition methods that require either separability or convexity of constraints, our approach is based on a new constraint partitioning theory and can handle nonconvex problems with inseparable global constraints. We also propose a hypergraph partitioning method to recognize the problem structure. Experimental results show that the proposed parallel algorithm can efficiently solve some difficult test cases.

  11. pcircle - A Suite of Scalable Parallel File System Tools

    Energy Science and Technology Software Center (OSTI)

    2015-10-01

    Most of the software related to file system are written for conventional local file system, they are serialized and can't take advantage of the benefit of a large scale parallel file system. "pcircle" software builds on top of ubiquitous MPI in cluster computing environment and "work-stealing" pattern to provide a scalable, high-performance suite of file system tools. In particular - it implemented parallel data copy and parallel data checksumming, with advanced features such as asyncmore » progress report, checkpoint and restart, as well as integrity checking.« less

  12. Parallel object-oriented data mining system

    DOE Patents [OSTI]

    Kamath, Chandrika; Cantu-Paz, Erick

    2004-01-06

    A data mining system uncovers patterns, associations, anomalies and other statistically significant structures in data. Data files are read and displayed. Objects in the data files are identified. Relevant features for the objects are extracted. Patterns among the objects are recognized based upon the features. Data from the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) sky survey was used to search for bent doubles. This test was conducted on data from the Very Large Array in New Mexico which seeks to locate a special type of quasar (radio-emitting stellar object) called bent doubles. The FIRST survey has generated more than 32,000 images of the sky to date. Each image is 7.1 megabytes, yielding more than 100 gigabytes of image data in the entire data set.

  13. Endpoint-based parallel data processing with non-blocking collective instructions in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Cernohous, Bob R; Ratterman, Joseph D; Smith, Brian E

    2014-11-11

    Endpoint-based parallel data processing with non-blocking collective instructions in a PAMI of a parallel computer is disclosed. The PAMI is composed of data communications endpoints, each including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task. The compute nodes are coupled for data communications through the PAMI. The parallel application establishes a data communications geometry specifying a set of endpoints that are used in collective operations of the PAMI by associating with the geometry a list of collective algorithms valid for use with the endpoints of the geometry; registering in each endpoint in the geometry a dispatch callback function for a collective operation; and executing without blocking, through a single one of the endpoints in the geometry, an instruction for the collective operation.

  14. Effect on Non-Uniform Heat Generation on Thermionic Reactions

    SciTech Connect (OSTI)

    Schock, Alfred

    2012-01-19

    The penalty resulting from non-uniform heat generation in a thermionic reactor is examined. Operation at sub-optimum cesium pressure is shown to reduce this penalty, but at the risk of a condition analogous to burnout. For high pressure diodes, a simple empirical correlation between current, voltage and heat flux is developed and used to analyze the performance penalty associated with two different heat flux profiles, for series-and parallel-connected converters. The results demonstrate that series-connected converters require much finer power flattening than parallel converters. For example, a 10% variation in heat generation across a series array can result in a 25 to 50% power penalty.

  15. Long-range triplet supercurrents induced by singlet supercurrents parallel to magnetic interfaces

    SciTech Connect (OSTI)

    Alidoust, Mohammad; Halterman, Klaus

    2014-11-17

    Employing a spin-parameterized Keldysh-Usadel technique for the diffusive regime, we demonstrate that even in the low proximity limit, considerable long-ranged triplet supercurrents can be effectively generated by spin-singlet supercurrents flowing parallel to the interfaces of uniform double ferromagnet interlayers with noncollinear exchange fields independent of actual junction geometry. The triplet supercurrents are found to be most pronounced when the thicknesses of the ferromagnet strips are unequal. To experimentally verify this generic phenomenon, we propose an accessible and controllable structure that can fully isolate the long-range triplet effects.

  16. CPIC: A Parallel Electrostatic Particle-In-Cell Code (Conference...

    Office of Scientific and Technical Information (OSTI)

    Electrostatic Particle-In-Cell Code Citation Details In-Document Search Title: CPIC: A Parallel Electrostatic Particle-In-Cell Code You are accessing a document from the ...

  17. Parallel Botulinum Neurotoxin/A Immuno- and Enzyme Activity Assays...

    Office of Scientific and Technical Information (OSTI)

    Title: Parallel Botulinum NeurotoxinA Immuno- and Enzyme Activity Assays Using the Versatile RapiDx Platform. Abstract not provided. Authors: Sommer, Gregory Jon ; Wang, Ying-Chih ...

  18. A Comprehensive Look at High Performance Parallel I/O

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In this era of "big data," high performance parallel IO-the way disk drives efficiently read and write information on HPC systems-is extremely important. Yet the last book to ...

  19. Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers Print Wednesday, 30 August 2006 00:00 Cooling an antiferromagnetic-ferromagnetic bilayer in a magnetic field typically results in a remanent (zero-field) magnetization in the ferromagnet (FM) that is always in the direction of the field during cooling (positive Mrem). Strikingly, when FeF2 is the antiferromagnet (AF), cooling in a field can lead to a remanent

  20. Mesoscale Simulations of Particulate Flows with Parallel Distributed

    Office of Scientific and Technical Information (OSTI)

    Lagrange Multiplier Technique (Conference) | SciTech Connect Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique Citation Details In-Document Search Title: Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique Fluid particulate flows are common phenomena in nature and industry. Modeling of such flows at micro and macro levels as well establishing relationships between these approaches are needed to

  1. Mesoscale simulations of particulate flows with parallel distributed

    Office of Scientific and Technical Information (OSTI)

    Lagrange multiplier technique (Journal Article) | SciTech Connect Journal Article: Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique Citation Details In-Document Search Title: Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique Authors: Kanarska, Y ; Lomov, I ; Antoun, T Publication Date: 2010-09-10 OSTI Identifier: 1120915 Report Number(s): LLNL-JRNL-455392 DOE Contract Number: W-7405-ENG-48

  2. Interface for Parallel I/O from Componentized Visualization Algorithms

    Energy Science and Technology Software Center (OSTI)

    2008-09-16

    The software is an interface layer over file I/O with features specifically designed for efficient parallel reads and writes. The interface provides multiple concrete implementations that easily allow the replacement of one interface with another. This feature allows a reader or writer implementation to work independently of whether parallel file I/O is available or desired. The software also contains extensions to some readers to allow it to use the file I/O functionality.

  3. Multiscale Molecular Simulations at the Petascale (Parallelization of

    Office of Scientific and Technical Information (OSTI)

    Reactive Force Field Model for Blue Gene/Q): ALCF-2 Early Science Program Technical Report (Technical Report) | SciTech Connect Multiscale Molecular Simulations at the Petascale (Parallelization of Reactive Force Field Model for Blue Gene/Q): ALCF-2 Early Science Program Technical Report Citation Details In-Document Search Title: Multiscale Molecular Simulations at the Petascale (Parallelization of Reactive Force Field Model for Blue Gene/Q): ALCF-2 Early Science Program Technical Report

  4. Allinea DDT as a Parallel Debugging Alternative to Totalview

    SciTech Connect (OSTI)

    Antypas, K.B.

    2007-03-05

    Totalview, from the Etnus Corporation, is a sophisticated and feature rich software debugger for parallel applications. As Totalview has gained in popularity and market share its pricing model has increased to the point where it is often prohibitively expensive for massively parallel supercomputers. Additionally, many of Totalview's advanced features are not used by members of the scientific computing community. For these reasons, supercomputing centers have begun to search for a basic parallel debugging tool which can be used as an alternative to Totalview. As the cost and complexity of Totalview has increased over the years, scientific computing centers have started searching for a viable parallel debugging alternative. DDT (Distributed Debugging Tool) from Allinea Software is a relatively new parallel debugging tool which aims to provide much of the same functionality as Totalview. This review outlines the basic features and limitations of DDT to determine if it can be a reasonable substitute for Totalview. DDT was tested on the NERSC platforms Bassi, Seaborg, Jacquard and Davinci with Fortran90, C, and C++ codes using MPI and OpenMP for parallelism.

  5. Sort-First, Distributed Memory Parallel Visualization and Rendering

    SciTech Connect (OSTI)

    Bethel, E. Wes; Humphreys, Greg; Paul, Brian; Brederson, J. Dean

    2003-07-15

    While commodity computing and graphics hardware has increased in capacity and dropped in cost, it is still quite difficult to make effective use of such systems for general-purpose parallel visualization and graphics. We describe the results of a recent project that provides a software infrastructure suitable for general-purpose use by parallel visualization and graphics applications. Our work combines and extends two technologies: Chromium, a stream-oriented framework that implements the OpenGL programming interface; and OpenRM Scene Graph, a pipelined-parallel scene graph interface for graphics data management. Using this combination, we implement a sort-first, distributed memory, parallel volume rendering application. We describe the performance characteristics in terms of bandwidth requirements and highlight key algorithmic considerations needed to implement the sort-first system. We characterize system performance using a distributed memory parallel volume rendering application, a nd present performance gains realized by using scene specific knowledge to accelerate rendering through reduced network bandwidth. The contribution of this work is an exploration of general-purpose, sort-first architecture performance characteristics as applied to distributed memory, commodity hardware, along with a description of the algorithmic support needed to realize parallel, sort-first implementations.

  6. Coiled transmission line pulse generators

    DOE Patents [OSTI]

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  7. ug[SCIP,*] Library : A Software Library for General Purpose Parallel...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ugSCIP,* Library : A Software Library for General Purpose Parallel Branch-and-Bound ... ugSCIP,* library is a software library to parallelize customized SCIP solvers. ...

  8. final report for Center for Programming Models for Scalable Parallel Computing

    SciTech Connect (OSTI)

    Johnson, Ralph E

    2013-04-10

    This is the final report of the work on parallel programming patterns that was part of the Center for Programming Models for Scalable Parallel Computing

  9. Sub-Second Parallel State Estimation (Technical Report) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Sub-Second Parallel State Estimation Citation Details In-Document Search Title: Sub-Second Parallel State Estimation This report describes the performance of ...

  10. Identifying the Root Causes of Wait States in Large-Scale Parallel Applications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Böhme, David; Geimer, Markus; Arnold, Lukas; Voigtlaender, Felix; Wolf, Felix

    2016-07-20

    Driven by growing application requirements and accelerated by current trends in microprocessor design, the number of processor cores on modern supercomputers is increasing from generation to generation. However, load or communication imbalance prevents many codes from taking advantage of the available parallelism, as delays of single processes may spread wait states across the entire machine. Moreover, when employing complex point-to-point communication patterns, wait states may propagate along far-reaching cause-effect chains that are hard to track manually and that complicate an assessment of the actual costs of an imbalance. Building on earlier work by Meira Jr. et al., we present amore » scalable approach that identifies program wait states and attributes their costs in terms of resource waste to their original cause. Ultimately, by replaying event traces in parallel both forward and backward, we can identify the processes and call paths responsible for the most severe imbalances even for runs with hundreds of thousands of processes.« less

  11. Parallel Breadth-First Search on Distributed Memory Systems

    SciTech Connect (OSTI)

    Computational Research Division; Buluc, Aydin; Madduri, Kamesh

    2011-04-15

    Data-intensive, graph-based computations are pervasive in several scientific applications, and are known to to be quite challenging to implement on distributed memory systems. In this work, we explore the design space of parallel algorithms for Breadth-First Search (BFS), a key subroutine in several graph algorithms. We present two highly-tuned par- allel approaches for BFS on large parallel systems: a level-synchronous strategy that relies on a simple vertex-based partitioning of the graph, and a two-dimensional sparse matrix- partitioning-based approach that mitigates parallel commu- nication overhead. For both approaches, we also present hybrid versions with intra-node multithreading. Our novel hybrid two-dimensional algorithm reduces communication times by up to a factor of 3.5, relative to a common vertex based approach. Our experimental study identifies execu- tion regimes in which these approaches will be competitive, and we demonstrate extremely high performance on lead- ing distributed-memory parallel systems. For instance, for a 40,000-core parallel execution on Hopper, an AMD Magny- Cours based system, we achieve a BFS performance rate of 17.8 billion edge visits per second on an undirected graph of 4.3 billion vertices and 68.7 billion edges with skewed degree distribution.

  12. Parallel Tensor Compression for Large-Scale Scientific Data.

    SciTech Connect (OSTI)

    Kolda, Tamara G.; Ballard, Grey; Austin, Woody Nathan

    2015-10-01

    As parallel computing trends towards the exascale, scientific data produced by high-fidelity simulations are growing increasingly massive. For instance, a simulation on a three-dimensional spatial grid with 512 points per dimension that tracks 64 variables per grid point for 128 time steps yields 8 TB of data. By viewing the data as a dense five way tensor, we can compute a Tucker decomposition to find inherent low-dimensional multilinear structure, achieving compression ratios of up to 10000 on real-world data sets with negligible loss in accuracy. So that we can operate on such massive data, we present the first-ever distributed memory parallel implementation for the Tucker decomposition, whose key computations correspond to parallel linear algebra operations, albeit with nonstandard data layouts. Our approach specifies a data distribution for tensors that avoids any tensor data redistribution, either locally or in parallel. We provide accompanying analysis of the computation and communication costs of the algorithms. To demonstrate the compression and accuracy of the method, we apply our approach to real-world data sets from combustion science simulations. We also provide detailed performance results, including parallel performance in both weak and strong scaling experiments.

  13. A Parallel Ghosting Algorithm for The Flexible Distributed Mesh Database

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mubarak, Misbah; Seol, Seegyoung; Lu, Qiukai; Shephard, Mark S.

    2013-01-01

    Critical to the scalability of parallel adaptive simulations are parallel control functions including load balancing, reduced inter-process communication and optimal data decomposition. In distributed meshes, many mesh-based applications frequently access neighborhood information for computational purposes which must be transmitted efficiently to avoid parallel performance degradation when the neighbors are on different processors. This article presents a parallel algorithm of creating and deleting data copies, referred to as ghost copies, which localize neighborhood data for computation purposes while minimizing inter-process communication. The key characteristics of the algorithm are: (1) It can create ghost copies of any permissible topological order inmore » a 1D, 2D or 3D mesh based on selected adjacencies. (2) It exploits neighborhood communication patterns during the ghost creation process thus eliminating all-to-all communication. (3) For applications that need neighbors of neighbors, the algorithm can create n number of ghost layers up to a point where the whole partitioned mesh can be ghosted. Strong and weak scaling results are presented for the IBM BG/P and Cray XE6 architectures up to a core count of 32,768 processors. The algorithm also leads to scalable results when used in a parallel super-convergent patch recovery error estimator, an application that frequently accesses neighborhood data to carry out computation.« less

  14. Parallel vacuum arc discharge with microhollow array dielectric and anode

    SciTech Connect (OSTI)

    Feng, Jinghua; Zhou, Lin; Fu, Yuecheng; Zhang, Jianhua; Xu, Rongkun; Chen, Faxin; Li, Linbo; Meng, Shijian

    2014-07-15

    An electrode configuration with microhollow array dielectric and anode was developed to obtain parallel vacuum arc discharge. Compared with the conventional electrodes, more than 10 parallel microhollow discharges were ignited for the new configuration, which increased the discharge area significantly and made the cathode eroded more uniformly. The vacuum discharge channel number could be increased effectively by decreasing the distances between holes or increasing the arc current. Experimental results revealed that plasmas ejected from the adjacent hollow and the relatively high arc voltage were two key factors leading to the parallel discharge. The characteristics of plasmas in the microhollow were investigated as well. The spectral line intensity and electron density of plasmas in microhollow increased obviously with the decease of the microhollow diameter.

  15. Parallel Scaling Characteristics of Selected NERSC User ProjectCodes

    SciTech Connect (OSTI)

    Skinner, David; Verdier, Francesca; Anand, Harsh; Carter,Jonathan; Durst, Mark; Gerber, Richard

    2005-03-05

    This report documents parallel scaling characteristics of NERSC user project codes between Fiscal Year 2003 and the first half of Fiscal Year 2004 (Oct 2002-March 2004). The codes analyzed cover 60% of all the CPU hours delivered during that time frame on seaborg, a 6080 CPU IBM SP and the largest parallel computer at NERSC. The scale in terms of concurrency and problem size of the workload is analyzed. Drawing on batch queue logs, performance data and feedback from researchers we detail the motivations, benefits, and challenges of implementing highly parallel scientific codes on current NERSC High Performance Computing systems. An evaluation and outlook of the NERSC workload for Allocation Year 2005 is presented.

  16. Parallel, adaptive finite element methods for conservation laws

    SciTech Connect (OSTI)

    Biswas, R.; Devine, K.D.; Flaherty, J.E. Rensselaer Polytechnic Institute, Troy, NY )

    1994-01-01

    We construct parallel finite element methods for the solution of hyperbolic conservation laws in one and two dimensions. Spatial discretization is performed by a discontinuous Galerkin finite element method using a basis of piecewise Legendre polynomials. Temporal discretization utilizes a Runge-Kutta method. Dissipative fluxes and projection limiting prevent oscillations near solution discontinuities. A posteriori estimates of spatial errors are obtained by a p-refinement technique using superconvergence at Radau points. The resulting method is of high order and may be parallelized efficiently on MIMD computers. We compare results using different limiting schemes and demonstrate parallel efficiency through computations on an NCUBE/2 hypercube. We also present results using adaptive h- and p-refinement to reduce the computational cost of the method.

  17. Parallel garbage collection on a virtual memory system

    SciTech Connect (OSTI)

    Abraham, S.G.; Patel, J.H.

    1987-01-01

    Since most artificial intelligence applications are programmed in list processing languages, it is important to design architectures to support efficient garbage collection. This paper presents an architecture and an associated algorithm for parallel garbage collection on a virtual memory system. All the previously proposed parallel algorithms attempt to collect cells released by the list processor during the garbage collection cycle. We do not attempt to collect such cells. As a consequence, the list processor incurs little overhead in the proposed scheme, since it need not synchronize with the collector. Most parallel algorithms are designed for shared memory machines which have certain implicit synchronization functions on variable access. The proposed algorithm is designed for virtual memory systems where both the list processor and the garbage collector have private memories. The enforcement of coherence between the two private memories can be expensive and is not necessary in our scheme. 15 refs., 3 figs.

  18. Parallel halo finding in N-body cosmology simulations

    SciTech Connect (OSTI)

    Pfitzner, D.W.; Salmon, J.K.

    1996-12-31

    Cosmological N-body simulations on parallel computers produce large datasets - about five hundred Megabytes at a single output time, or tens of Gigabytes over the course of a simulation. These large datasets require further analysis before they can be compared to astronomical observations. We have implemented two methods for performing halo finding, a key part of the knowledge discovery process, on parallel machines. One of these is a parallel implementation of the friends of friends (FOF) algorithm, widely used in the field of N-body cosmology. The new isodensity (ID) method has been developed to overcome some of the shortcomings of FOR Both have been implemented on a variety of computer systems, and successfully used to extract halos from simulations with up to 256{sup 3} (or about 16.8 million) particles, which axe among the largest N-body cosmology simulations in existence.

  19. Methods for operating parallel computing systems employing sequenced communications

    DOE Patents [OSTI]

    Benner, Robert E.; Gustafson, John L.; Montry, Gary R.

    1999-01-01

    A parallel computing system and method having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system.

  20. Performance analysis of parallel supernodal sparse LU factorization

    SciTech Connect (OSTI)

    Grigori, Laura; Li, Xiaoye S.

    2004-02-05

    We investigate performance characteristics for the LU factorization of large matrices with various sparsity patterns. We consider supernodal right-looking parallel factorization on a bi-dimensional grid of processors, making use of static pivoting. We develop a performance model and we validate it using the implementation in SuperLU-DIST, the real matrices and the IBM Power3 machine at NERSC. We use this model to obtain performance bounds on parallel computers, to perform scalability analysis and to identify performance bottlenecks. We also discuss the role of load balance and data distribution in this approach.

  1. Parallel Harmony Search Based Distributed Energy Resource Optimization

    SciTech Connect (OSTI)

    Ceylan, Oguzhan; Liu, Guodong; Tomsovic, Kevin

    2015-01-01

    This paper presents a harmony search based parallel optimization algorithm to minimize voltage deviations in three phase unbalanced electrical distribution systems and to maximize active power outputs of distributed energy resources (DR). The main contribution is to reduce the adverse impacts on voltage profile during a day as photovoltaics (PVs) output or electrical vehicles (EVs) charging changes throughout a day. The IEEE 123- bus distribution test system is modified by adding DRs and EVs under different load profiles. The simulation results show that by using parallel computing techniques, heuristic methods may be used as an alternative optimization tool in electrical power distribution systems operation.

  2. Methods for operating parallel computing systems employing sequenced communications

    DOE Patents [OSTI]

    Benner, R.E.; Gustafson, J.L.; Montry, G.R.

    1999-08-10

    A parallel computing system and method are disclosed having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system. 15 figs.

  3. Electric power monthly, February 1999 with data for November 1998

    SciTech Connect (OSTI)

    1999-02-01

    The Electric Power Monthly presents monthly electricity statistics for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The purpose of this publication is to provide energy decision makers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Statistics are provided for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity retail sales, associated revenue, and average revenue per kilowatt-hour of electricity sold.

  4. Wind energy systems have low operating expenses because they have no fuel cost.

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    energy systems have low operating expenses because they have no fuel cost. Photo by Jenny Hager Photography, NREL 15990. 1. Wind energy is cost competitive with other fuel sources. The average levelized price of wind power purchase agree- ments signed in 2013 was approximately 2.5 cents per kilowatt-hour, a price that is not only cost competitive with new gas-fired power plants but also compares favorably to a range of fuel cost projections of gas-fired generation extending out through 2040. 1

  5. Super Bowl of Energy: Solar Smashes Records | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Super Bowl of Energy: Solar Smashes Records Super Bowl of Energy: Solar Smashes Records February 3, 2014 - 5:45pm Addthis MetLife Stadium, the site of yesterday's Super Bowl, features a ring of 1,350 solar panels that can generate 350,000 kilowatt hours of electricity annually. The number of jobs in the U.S. solar energy industry equates to nearly double the amount of seats in the stadium. Picture courtesy NRG Solar, LLC MetLife Stadium, the site of yesterday's Super Bowl, features a ring of

  6. Tax Incentives

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tax Incentives of 1992, allows owners of qualified over a 10-year period. Qualified wind wind turbines (indexed for inflation). - The federal Renewable Electricity Production Tax Credit (PTC), established by the Energy Policy Act renewable energy facilities to receive tax credits for each kilowatt-hour (kWh) of electricity generated by the facility power projects are eligible to receive 2.3 cents per kWh for the produc - tion of electricity from utility-scale dsireusa.org/incentives/incentive.

  7. Wind Energy Benefits (Fact Sheet), WINDExchange, U.S. Department of Energy (DOE), Energy Efficiency & Renewable Energy (EERE)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    competitive with other fuel sources. The average levelized price of wind power purchase agreements signed in 2013 was approximately 2.5 cents per kilowatt-hour, a price that is not only cost competitive with new gas-fred power plants but also compares favorably to a range of fuel cost projections of gas-fred generation extending out through 2040. 1 Public and private research and development (R&D) can provide continued technological advancements and further reduce wind energy costs. 2 2.

  8. Project Reports for Soboba Band of Luiseño Indians - 2015 Project |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Soboba Band of Luiseño Indians - 2015 Project Project Reports for Soboba Band of Luiseño Indians - 2015 Project Under this grant, the Soboba Band of Luiseño Indians plans to install the Soboba Community Solar Energy Project, a 1.0-megawatt (MW) AC ground-mounted photovoltaic (PV) system that, once installed, will generate approximately 1,884,686 kilowatt-hours (kWh)/year, meeting 80% of the annual energy needs of key community facilities. March 2015 status report

  9. Soboba Band of Luiseño Indians - 2015 Project | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Luiseño Indians - 2015 Project Soboba Band of Luiseño Indians - 2015 Project Summary The Soboba Community Solar Energy Project proposes installation of a 1.0-megawatt (MW) AC ground-mounted photovoltaic (PV) system that, once installed, will generate approximately 1,884,686 kilowatt-hours (kWh)/year, meeting 80% of the annual energy needs of key community facilities. The project will benefit every tribal member since the cost of running the community facilities, including electric bills, comes

  10. Engineering innovation to reduce wind power COE

    SciTech Connect (OSTI)

    Ammerman, Curtt Nelson

    2011-01-10

    There are enough wind resources in the US to provide 10 times the electric power we currently use, however wind power only accounts for 2% of our total electricity production. One of the main limitations to wind use is cost. Wind power currently costs 5-to-8 cents per kilowatt-hour, which is more than twice the cost of electricity generated by burning coal. Our Intelligent Wind Turbine LDRD Project is applying LANL's leading-edge engineering expertise in modeling and simulation, experimental validation, and advanced sensing technologies to challenges faced in the design and operation of modern wind turbines.

  11. SunShot Initiative 2014 Peer Review Report

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    SunShot Initiative 2014 Peer Review Report August 2014 SunShot Initiative 2014 Peer Review Report * i Message from the Director Message from the Director In 2011, the U.S. Department of Energy (DOE) launched the SunShot Initiative to drive down the costs of solar pow- er to $0.06 per kilowatt hour by 2020 so that solar can compete with traditional energy generation. To achieve these goals SunShot continually challenges the solar community to develop innovative projects, new solutions, and pursue

  12. Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage

    Broader source: Energy.gov [DOE]

    The Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage (CSP: ELEMENTS) funding program supports the development of thermochemical energy storage (TCES) systems that can validate a cost of less than or equal to $15 per kilowatt-hour-thermal (kWht) and operate at temperatures greater than or equal to 650 degrees Celsius. TCES presents opportunities for storing the sun's energy at high densities in the form of chemical bonds for use in utility-scale concentrating solar power (CSP) electricity generation. The SunShot Initiative funds six awardees for $10 million total for ELEMENTS.

  13. Building a Parallel Cloud Storage System using OpenStacks Swift Object Store and Transformative Parallel I/O

    SciTech Connect (OSTI)

    Burns, Andrew J.; Lora, Kaleb D.; Martinez, Esteban; Shorter, Martel L.

    2012-07-30

    Our project consists of bleeding-edge research into replacing the traditional storage archives with a parallel, cloud-based storage solution. It used OpenStack's Swift Object Store cloud software. It's Benchmarked Swift for write speed and scalability. Our project is unique because Swift is typically used for reads and we are mostly concerned with write speeds. Cloud Storage is a viable archive solution because: (1) Container management for larger parallel archives might ease the migration workload; (2) Many tools that are written for cloud storage could be utilized for local archive; and (3) Current large cloud storage practices in industry could be utilized to manage a scalable archive solution.

  14. Parallel heat transport in integrable and chaotic magnetic fields

    SciTech Connect (OSTI)

    Del-Castillo-Negrete, Diego B [ORNL; Chacon, Luis [ORNL

    2012-01-01

    The study of transport in magnetized plasmas is a problem of fundamental interest in controlled fusion, space plasmas, and astrophysics research. Three issues make this problem particularly chal- lenging: (i) The extreme anisotropy between the parallel (i.e., along the magnetic field), , and the perpendicular, , conductivities ( / may exceed 1010 in fusion plasmas); (ii) Magnetic field lines chaos which in general complicates (and may preclude) the construction of magnetic field line coordinates; and (iii) Nonlocal parallel transport in the limit of small collisionality. Motivated by these issues, we present a Lagrangian Green s function method to solve the local and non-local parallel transport equation applicable to integrable and chaotic magnetic fields in arbitrary geom- etry. The method avoids by construction the numerical pollution issues of grid-based algorithms. The potential of the approach is demonstrated with nontrivial applications to integrable (magnetic island chain), weakly chaotic (devil s staircase), and fully chaotic magnetic field configurations. For the latter, numerical solutions of the parallel heat transport equation show that the effective radial transport, with local and non-local closures, is non-diffusive, thus casting doubts on the appropriateness of the applicability of quasilinear diffusion descriptions. General conditions for the existence of non-diffusive, multivalued flux-gradient relations in the temperature evolution are derived.

  15. A massively parallel fractional step solver for incompressible flows

    SciTech Connect (OSTI)

    Houzeaux, G. Vazquez, M. Aubry, R. Cela, J.M.

    2009-09-20

    This paper presents a parallel implementation of fractional solvers for the incompressible Navier-Stokes equations using an algebraic approach. Under this framework, predictor-corrector and incremental projection schemes are seen as sub-classes of the same class, making apparent its differences and similarities. An additional advantage of this approach is to set a common basis for a parallelization strategy, which can be extended to other split techniques or to compressible flows. The predictor-corrector scheme consists in solving the momentum equation and a modified 'continuity' equation (namely a simple iteration for the pressure Schur complement) consecutively in order to converge to the monolithic solution, thus avoiding fractional errors. On the other hand, the incremental projection scheme solves only one iteration of the predictor-corrector per time step and adds a correction equation to fulfill the mass conservation. As shown in the paper, these two schemes are very well suited for massively parallel implementation. In fact, when compared with monolithic schemes, simpler solvers and preconditioners can be used to solve the non-symmetric momentum equations (GMRES, Bi-CGSTAB) and to solve the symmetric continuity equation (CG, Deflated CG). This gives good speedup properties of the algorithm. The implementation of the mesh partitioning technique is presented, as well as the parallel performances and speedups for thousands of processors.

  16. An intercalation-locked parallel-stranded DNA tetraplex

    SciTech Connect (OSTI)

    Tripathi, S.; Zhang, D.; Paukstelis, P. J.

    2015-01-27

    DNA has proved to be an excellent material for nanoscale construction because complementary DNA duplexes are programmable and structurally predictable. However, in the absence of Watson–Crick pairings, DNA can be structurally more diverse. Here, we describe the crystal structures of d(ACTCGGATGAT) and the brominated derivative, d(ACBrUCGGABrUGAT). These oligonucleotides form parallel-stranded duplexes with a crystallographically equivalent strand, resulting in the first examples of DNA crystal structures that contains four different symmetric homo base pairs. Two of the parallel-stranded duplexes are coaxially stacked in opposite directions and locked together to form a tetraplex through intercalation of the 5'-most A–A base pairs between adjacent G–G pairs in the partner duplex. The intercalation region is a new type of DNA tertiary structural motif with similarities to the i-motif. 1H–1H nuclear magnetic resonance and native gel electrophoresis confirmed the formation of a parallel-stranded duplex in solution. Finally, we modified specific nucleotide positions and added d(GAY) motifs to oligonucleotides and were readily able to obtain similar crystals. This suggests that this parallel-stranded DNA structure may be useful in the rational design of DNA crystals and nanostructures.

  17. Hardware packet pacing using a DMA in a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Heidelberger, Phillip; Vranas, Pavlos

    2013-08-13

    Method and system for hardware packet pacing using a direct memory access controller in a parallel computer which, in one aspect, keeps track of a total number of bytes put on the network as a result of a remote get operation, using a hardware token counter.

  18. An intercalation-locked parallel-stranded DNA tetraplex

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tripathi, S.; Zhang, D.; Paukstelis, P. J.

    2015-01-27

    DNA has proved to be an excellent material for nanoscale construction because complementary DNA duplexes are programmable and structurally predictable. However, in the absence of Watson–Crick pairings, DNA can be structurally more diverse. Here, we describe the crystal structures of d(ACTCGGATGAT) and the brominated derivative, d(ACBrUCGGABrUGAT). These oligonucleotides form parallel-stranded duplexes with a crystallographically equivalent strand, resulting in the first examples of DNA crystal structures that contains four different symmetric homo base pairs. Two of the parallel-stranded duplexes are coaxially stacked in opposite directions and locked together to form a tetraplex through intercalation of the 5'-most A–A base pairs betweenmore » adjacent G–G pairs in the partner duplex. The intercalation region is a new type of DNA tertiary structural motif with similarities to the i-motif. 1H–1H nuclear magnetic resonance and native gel electrophoresis confirmed the formation of a parallel-stranded duplex in solution. Finally, we modified specific nucleotide positions and added d(GAY) motifs to oligonucleotides and were readily able to obtain similar crystals. This suggests that this parallel-stranded DNA structure may be useful in the rational design of DNA crystals and nanostructures.« less

  19. Lamb dip asymmetry in lasers with plane-parallel resonators

    SciTech Connect (OSTI)

    Tache, J.P.; Le Floch, A.; Le Naour, R.

    1986-09-01

    The Lamb dip asymmetry due to linear or nonlinear lenslike effects is investigated in lasers with plane-parallel resonators. The experiments are performed using diffracted light spectroscopy. It is shown that the frequency-dependent diffraction losses are essential in determining Lamb dip asymmetry, regardless of the origin of the lenslike effects.

  20. Xyce Parallel Electronic Simulator Users Guide Version 6.2.

    SciTech Connect (OSTI)

    Keiter, Eric R.; Mei, Ting; Russo, Thomas V.; Schiek, Richard; Sholander, Peter E.; Thornquist, Heidi K.; Verley, Jason; Baur, David Gregory

    2014-09-01

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been de- signed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel com- puting platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to develop new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandia's needs, including some radiation- aware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase -- a message passing parallel implementation -- which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. Trademarks The information herein is subject to change without notice. Copyright c 2002-2014 Sandia Corporation. All rights reserved. Xyce TM Electronic Simulator and Xyce TM are trademarks of Sandia Corporation. Portions of the Xyce TM code are: Copyright c 2002, The Regents of the University of California. Produced at the Lawrence Livermore National Laboratory. Written by Alan Hindmarsh, Allan Taylor, Radu Serban. UCRL-CODE-2002-59 All rights reserved. Orcad, Orcad Capture, PSpice and Probe are

  1. Nurbs and grid generation

    SciTech Connect (OSTI)

    Barnhill, R.E.; Farin, G.; Hamann, B.

    1995-12-31

    This paper provides a basic overview of NURBS and their application to numerical grid generation. Curve/surface smoothing, accelerated grid generation, and the use of NURBS in a practical grid generation system are discussed.

  2. Explicit spatial scattering for load balancing in conservatively synchronized parallel discrete-event simulations

    SciTech Connect (OSTI)

    Thulasidasan, Sunil; Kasiviswanathan, Shiva; Eidenbenz, Stephan; Romero, Philip

    2010-01-01

    We re-examine the problem of load balancing in conservatively synchronized parallel, discrete-event simulations executed on high-performance computing clusters, focusing on simulations where computational and messaging load tend to be spatially clustered. Such domains are frequently characterized by the presence of geographic 'hot-spots' - regions that generate significantly more simulation events than others. Examples of such domains include simulation of urban regions, transportation networks and networks where interaction between entities is often constrained by physical proximity. Noting that in conservatively synchronized parallel simulations, the speed of execution of the simulation is determined by the slowest (i.e most heavily loaded) simulation process, we study different partitioning strategies in achieving equitable processor-load distribution in domains with spatially clustered load. In particular, we study the effectiveness of partitioning via spatial scattering to achieve optimal load balance. In this partitioning technique, nearby entities are explicitly assigned to different processors, thereby scattering the load across the cluster. This is motivated by two observations, namely, (i) since load is spatially clustered, spatial scattering should, intuitively, spread the load across the compute cluster, and (ii) in parallel simulations, equitable distribution of CPU load is a greater determinant of execution speed than message passing overhead. Through large-scale simulation experiments - both of abstracted and real simulation models - we observe that scatter partitioning, even with its greatly increased messaging overhead, significantly outperforms more conventional spatial partitioning techniques that seek to reduce messaging overhead. Further, even if hot-spots change over the course of the simulation, if the underlying feature of spatial clustering is retained, load continues to be balanced with spatial scattering leading us to the observation that

  3. Generator stator core vent duct spacer posts

    DOE Patents [OSTI]

    Griffith, John Wesley; Tong, Wei

    2003-06-24

    Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

  4. The Fortran-P Translator: Towards Automatic Translation of Fortran 77 Programs for Massively Parallel Processors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    O'keefe, Matthew; Parr, Terence; Edgar, B. Kevin; Anderson, Steve; Woodward, Paul; Dietz, Hank

    1995-01-01

    Massively parallel processors (MPPs) hold the promise of extremely high performance that, if realized, could be used to study problems of unprecedented size and complexity. One of the primary stumbling blocks to this promise has been the lack of tools to translate application codes to MPP form. In this article we show how applications codes written in a subset of Fortran 77, called Fortran-P, can be translated to achieve good performance on several massively parallel machines. This subset can express codes that are self-similar, where the algorithm applied to the global data domain is also applied to each subdomain. Wemore » have found many codes that match the Fortran-P programming style and have converted them using our tools. We believe a self-similar coding style will accomplish what a vectorizable style has accomplished for vector machines by allowing the construction of robust, user-friendly, automatic translation systems that increase programmer productivity and generate fast, efficient code for MPPs.« less

  5. Parallel, distributed and GPU computing technologies in single-particle electron microscopy

    SciTech Connect (OSTI)

    Schmeisser, Martin; Heisen, Burkhard C.; Luettich, Mario; Busche, Boris; Hauer, Florian; Koske, Tobias; Knauber, Karl-Heinz; Stark, Holger

    2009-07-01

    An introduction to the current paradigm shift towards concurrency in software. Most known methods for the determination of the structure of macromolecular complexes are limited or at least restricted at some point by their computational demands. Recent developments in information technology such as multicore, parallel and GPU processing can be used to overcome these limitations. In particular, graphics processing units (GPUs), which were originally developed for rendering real-time effects in computer games, are now ubiquitous and provide unprecedented computational power for scientific applications. Each parallel-processing paradigm alone can improve overall performance; the increased computational performance obtained by combining all paradigms, unleashing the full power of todays technology, makes certain applications feasible that were previously virtually impossible. In this article, state-of-the-art paradigms are introduced, the tools and infrastructure needed to apply these paradigms are presented and a state-of-the-art infrastructure and solution strategy for moving scientific applications to the next generation of computer hardware is outlined.

  6. High voltage pulse generator. [Patent application

    DOE Patents [OSTI]

    Fasching, G.E.

    1975-06-12

    An improved high-voltage pulse generator is described which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of the first rectifier connected between the first and second capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. The output voltage can be readily increased by adding additional charging networks. The circuit allows the peak level of the output to be easily varied over a wide range by using a variable autotransformer in the charging circuit.

  7. Parallelization and checkpointing of GPU applications through program transformation

    SciTech Connect (OSTI)

    Solano-Quinde, Lizandro Dami#19;an

    2012-11-15

    GPUs have emerged as a powerful tool for accelerating general-purpose applications. The availability of programming languages that makes writing general-purpose applications for running on GPUs tractable have consolidated GPUs as an alternative for accelerating general purpose applications. Among the areas that have beneffited from GPU acceleration are: signal and image processing, computational fluid dynamics, quantum chemistry, and, in general, the High Performance Computing (HPC) Industry. In order to continue to exploit higher levels of parallelism with GPUs, multi-GPU systems are gaining popularity. In this context, single-GPU applications are parallelized for running in multi-GPU systems. Furthermore, multi-GPU systems help to solve the GPU memory limitation for applications with large application memory footprint. Parallelizing single-GPU applications has been approached by libraries that distribute the workload at runtime, however, they impose execution overhead and are not portable. On the other hand, on traditional CPU systems, parallelization has been approached through application transformation at pre-compile time, which enhances the application to distribute the workload at application level and does not have the issues of library-based approaches. Hence, a parallelization scheme for GPU systems based on application transformation is needed. Like any computing engine of today, reliability is also a concern in GPUs. GPUs are vulnerable to transient and permanent failures. Current checkpoint/restart techniques are not suitable for systems with GPUs. Checkpointing for GPU systems present new and interesting challenges, primarily due to the natural differences imposed by the hardware design, the memory subsystem architecture, the massive number of threads, and the limited amount of synchronization among threads. Therefore, a checkpoint/restart technique suitable for GPU systems is needed. The goal of this work is to exploit higher levels of parallelism

  8. Data consistency conditions for truncated fanbeam and parallel projections

    SciTech Connect (OSTI)

    Clackdoyle, Rolf; Desbat, Laurent

    2015-02-15

    Purpose: In image reconstruction from projections, data consistency conditions (DCCs) are mathematical relationships that express the overlap of information between ideal projections. DCCs have been incorporated in image reconstruction procedures for positron emission tomography, single photon emission computed tomography, and x-ray computed tomography (CT). Building on published fanbeam DCCs for nontruncated projections along a line, the authors recently announced new DCCs that can be applied to truncated parallel projections in classical (two-dimensional) image reconstruction. These DCCs take the form of polynomial expressions for a weighted backprojection of the projections. The purpose of this work was to present the new DCCs for truncated parallel projections, to extend these conditions to truncated fanbeam projections on a circular trajectory, to verify the conditions with numerical examples, and to present a model of how DCCs could be applied with a toy problem in patient motion estimation with truncated projections. Methods: A mathematical derivation of the new parallel DCCs was performed by substituting the underlying imaging equation into the mathematical expression for the weighted backprojection and demonstrating the resulting polynomial form. This DCC result was extended to fanbeam projections by a substitution of parallel to fanbeam variables. Ideal fanbeam projections of a simple mathematical phantom were simulated and the DCCs for these projections were evaluated by fitting polynomials to the weighted backprojection. For the motion estimation problem, a parametrized motion was simulated using a dynamic version of the mathematical phantom, and both noiseless and noisy fanbeam projections were simulated for a full circular trajectory. The fanbeam DCCs were applied to extract the motion parameters, which allowed the motion contamination to be removed from the projections. A reconstruction was performed from the corrected projections. Results: The

  9. Hydrogen Generator Appliance

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    J slide presentation: hydrogen Generator appliance Gus Block, Nuvera Fuel Cells

  10. Six-color procedure for the parallel solution of elliptic systems using the finite quadtree structures. Rept. for Mar-Nov 90

    SciTech Connect (OSTI)

    Benantar, M.; Flaherty, J.E.

    1990-01-01

    We consider the parallel assembly and solution on shared-memory computers of linear algebraic systems arising from the finite element discretization of two-dimensional linear self-adjoint elliptic problems. Stiffness matrix assembly and conjugate gradient solution of the linear system using element-by-element and symmetric successive over-relaxation preconditioners are processed in parallel with computations scheduled on noncontiguous regions in order to minimize process synchronization. An underlying quadtree structure, used for automatic mesh generation and solution-based mesh refinement, is separated into disjoint regions called quadrants using six-color procedure having linear time complexity.

  11. Recent progress and advances in iterative software (including parallel aspects)

    SciTech Connect (OSTI)

    Carey, G.; Young, D.M.; Kincaid, D.

    1994-12-31

    The purpose of the workshop is to provide a forum for discussion of the current state of iterative software packages. Of particular interest is software for large scale engineering and scientific applications, especially for distributed parallel systems. However, the authors will also review the state of software development for conventional architectures. This workshop will complement the other proposed workshops on iterative BLAS kernels and applications. The format for the workshop is as follows: To provide some structure, there will be brief presentations, each of less than five minutes duration and dealing with specific facets of the subject. These will be designed to focus the discussion and to stimulate an exchange with the participants. Issues to be covered include: The evolution of iterative packages, current state of the art, the parallel computing challenge, applications viewpoint, standards, and future directions and open problems.

  12. Administering truncated receive functions in a parallel messaging interface

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-12-09

    Administering truncated receive functions in a parallel messaging interface (`PMI`) of a parallel computer comprising a plurality of compute nodes coupled for data communications through the PMI and through a data communications network, including: sending, through the PMI on a source compute node, a quantity of data from the source compute node to a destination compute node; specifying, by an application on the destination compute node, a portion of the quantity of data to be received by the application on the destination compute node and a portion of the quantity of data to be discarded; receiving, by the PMI on the destination compute node, all of the quantity of data; providing, by the PMI on the destination compute node to the application on the destination compute node, only the portion of the quantity of data to be received by the application; and discarding, by the PMI on the destination compute node, the portion of the quantity of data to be discarded.

  13. Laser Safety Method For Duplex Open Loop Parallel Optical Link

    DOE Patents [OSTI]

    Baumgartner, Steven John; Hedin, Daniel Scott; Paschal, Matthew James

    2003-12-02

    A method and apparatus are provided to ensure that laser optical power does not exceed a "safe" level in an open loop parallel optical link in the event that a fiber optic ribbon cable is broken or otherwise severed. A duplex parallel optical link includes a transmitter and receiver pair and a fiber optic ribbon that includes a designated number of channels that cannot be split. The duplex transceiver includes a corresponding transmitter and receiver that are physically attached to each other and cannot be detached therefrom, so as to ensure safe, laser optical power in the event that the fiber optic ribbon cable is broken or severed. Safe optical power is ensured by redundant current and voltage safety checks.

  14. JPARSS: A Java Parallel Network Package for Grid Computing

    SciTech Connect (OSTI)

    Chen, Jie; Akers, Walter; Chen, Ying; Watson, William

    2002-03-01

    The emergence of high speed wide area networks makes grid computinga reality. However grid applications that need reliable data transfer still have difficulties to achieve optimal TCP performance due to network tuning of TCP window size to improve bandwidth and to reduce latency on a high speed wide area network. This paper presents a Java package called JPARSS (Java Parallel Secure Stream (Socket)) that divides data into partitions that are sent over several parallel Java streams simultaneously and allows Java or Web applications to achieve optimal TCP performance in a grid environment without the necessity of tuning TCP window size. This package enables single sign-on, certificate delegation and secure or plain-text data transfer using several security components based on X.509 certificate and SSL. Several experiments will be presented to show that using Java parallelstreams is more effective than tuning TCP window size. In addition a simple architecture using Web services

  15. Scalable parallel solution coupling for multi-physics reactor simulation.

    SciTech Connect (OSTI)

    Tautges, T. J.; Caceres, A.; Mathematics and Computer Science

    2009-01-01

    Reactor simulation depends on the coupled solution of various physics types, including neutronics, thermal/hydraulics, and structural mechanics. This paper describes the formulation and implementation of a parallel solution coupling capability being developed for reactor simulation. The coupling process consists of mesh and coupler initialization, point location, field interpolation, and field normalization. We report here our test of this capability on an example problem, namely, a reflector assembly from an advanced burner test reactor. Performance of this coupler in parallel is reasonable for the chosen problem size and range of processor counts. The runtime is dominated by startup costs, which amortize over the entire coupled simulation. Future efforts will include adding more sophisticated interpolation and normalization methods, to accommodate different numerical solvers used in various physics modules and to obtain better conservation properties for certain field types.

  16. Parallel Algorithms for Graph Optimization using Tree Decompositions

    SciTech Connect (OSTI)

    Sullivan, Blair D; Weerapurage, Dinesh P; Groer, Christopher S

    2012-06-01

    Although many $\\cal{NP}$-hard graph optimization problems can be solved in polynomial time on graphs of bounded tree-width, the adoption of these techniques into mainstream scientific computation has been limited due to the high memory requirements of the necessary dynamic programming tables and excessive runtimes of sequential implementations. This work addresses both challenges by proposing a set of new parallel algorithms for all steps of a tree decomposition-based approach to solve the maximum weighted independent set problem. A hybrid OpenMP/MPI implementation includes a highly scalable parallel dynamic programming algorithm leveraging the MADNESS task-based runtime, and computational results demonstrate scaling. This work enables a significant expansion of the scale of graphs on which exact solutions to maximum weighted independent set can be obtained, and forms a framework for solving additional graph optimization problems with similar techniques.

  17. Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses

    SciTech Connect (OSTI)

    Dridi, G.; Guerin, S.; Hakobyan, V.; Jauslin, H. R.; Eleuch, H.

    2009-10-15

    We present a general and versatile technique of population transfer based on parallel adiabatic passage by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3{pi}, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically picosecond and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ultrafast robust population transfer with interesting applications in quantum information processing.

  18. Coupled Serial and Parallel Non-uniform SQUIDs

    SciTech Connect (OSTI)

    Longhini, Patrick; In, Visarath; Berggren, Susan; Palacios, Antonio; Leese de Escobar, Anna

    2011-04-19

    In this work we numerical model series and parallel non-uniform superconducting quantum interference device (SQUID) array. Previous work has shown that series SQUID array constructed with a random distribution of loop sizes, (i.e. different areas for each SQUID loop) there exists a unique 'anti-peak' at the zero magnetic field for the voltage versus applied magnetic field (V-B). Similar results extend to a parallel SQUID array where the difference lies in the arrangement of the Josephson junctions. Other system parameter such as bias current, the number of loops, and mutual inductances are varied to demonstrate the change in dynamic range and linearity of the V-B response. Application of the SQUID array as a low noise amplifier (LNA) would increase link margins and affect the entire communication system. For unmanned aerial vehicles (UAVs), size, weight and power are limited, the SQUID array would allow use of practical 'electrically small' antennas that provide acceptable gain.

  19. Performance evaluation of a parallel sparse lattice Boltzmann solver

    SciTech Connect (OSTI)

    Axner, L. Bernsdorf, J. Zeiser, T. Lammers, P. Linxweiler, J. Hoekstra, A.G.

    2008-05-01

    We develop a performance prediction model for a parallelized sparse lattice Boltzmann solver and present performance results for simulations of flow in a variety of complex geometries. A special focus is on partitioning and memory/load balancing strategy for geometries with a high solid fraction and/or complex topology such as porous media, fissured rocks and geometries from medical applications. The topology of the lattice nodes representing the fluid fraction of the computational domain is mapped on a graph. Graph decomposition is performed with both multilevel recursive-bisection and multilevel k-way schemes based on modified Kernighan-Lin and Fiduccia-Mattheyses partitioning algorithms. Performance results and optimization strategies are presented for a variety of platforms, showing a parallel efficiency of almost 80% for the largest problem size. A good agreement between the performance model and experimental results is demonstrated.

  20. Performing a local reduction operation on a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A; Faraj, Daniel A

    2013-06-04

    A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

  1. Establishing a group of endpoints in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.; Xue, Hanhong

    2016-02-02

    A parallel computer executes a number of tasks, each task includes a number of endpoints and the endpoints are configured to support collective operations. In such a parallel computer, establishing a group of endpoints receiving a user specification of a set of endpoints included in a global collection of endpoints, where the user specification defines the set in accordance with a predefined virtual representation of the endpoints, the predefined virtual representation is a data structure setting forth an organization of tasks and endpoints included in the global collection of endpoints and the user specification defines the set of endpoints without a user specification of a particular endpoint; and defining a group of endpoints in dependence upon the predefined virtual representation of the endpoints and the user specification.

  2. Parallel computation of transverse wakes in linear colliders

    SciTech Connect (OSTI)

    Zhan, Xiaowei; Ko, Kwok

    1996-11-01

    SLAC has proposed the detuned structure (DS) as one possible design to control the emittance growth of long bunch trains due to transverse wakefields in the Next Linear Collider (NLC). The DS consists of 206 cells with tapering from cell to cell of the order of few microns to provide Gaussian detuning of the dipole modes. The decoherence of these modes leads to two orders of magnitude reduction in wakefield experienced by the trailing bunch. To model such a large heterogeneous structure realistically is impractical with finite-difference codes using structured grids. The authors have calculated the wakefield in the DS on a parallel computer with a finite-element code using an unstructured grid. The parallel implementation issues are presented along with simulation results that include contributions from higher dipole bands and wall dissipation.

  3. Beam Dynamics Studies of Parallel-Bar Deflecting Cavities

    SciTech Connect (OSTI)

    S. Ahmed, G. Krafft, K. Detrick, S. Silva, J. Delayen, M. Spata ,M. Tiefenback, A. Hofler ,K. Beard

    2011-03-01

    We have performed three-dimensional simulations of beam dynamics for parallel-bar transverse electromagnetic mode (TEM) type RF separators: normal- and super-conducting. The compact size of these cavities as compared to conventional TM$_{110}$ type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a one- or two-cell superconducting structure are enough to produce the required vertical displacement at the Lambertson magnet. Both the normal and super-conducting structures show very small emittance dilution due to the vertical kick of the beam.

  4. Performing a local reduction operation on a parallel computer

    SciTech Connect (OSTI)

    Blocksome, Michael A.; Faraj, Daniel A.

    2012-12-11

    A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

  5. Data-Parallel Mesh Connected Components Labeling and Analysis

    SciTech Connect (OSTI)

    Harrison, Cyrus; Childs, Hank; Gaither, Kelly

    2011-04-10

    We present a data-parallel algorithm for identifying and labeling the connected sub-meshes within a domain-decomposed 3D mesh. The identification task is challenging in a distributed-memory parallel setting because connectivity is transitive and the cells composing each sub-mesh may span many or all processors. Our algorithm employs a multi-stage application of the Union-find algorithm and a spatial partitioning scheme to efficiently merge information across processors and produce a global labeling of connected sub-meshes. Marking each vertex with its corresponding sub-mesh label allows us to isolate mesh features based on topology, enabling new analysis capabilities. We briefly discuss two specific applications of the algorithm and present results from a weak scaling study. We demonstrate the algorithm at concurrency levels up to 2197 cores and analyze meshes containing up to 68 billion cells.

  6. Parallel resistivity and ohmic heating of laboratory dipole plasmas

    SciTech Connect (OSTI)

    Fox, W.

    2012-08-15

    The parallel resistivity is calculated in the long-mean-free-path regime for the dipole plasma geometry; this is shown to be a neoclassical transport problem in the limit of a small number of circulating electrons. In this regime, the resistivity is substantially higher than the Spitzer resistivity due to the magnetic trapping of a majority of the electrons. This suggests that heating the outer flux surfaces of the plasma with low-frequency parallel electric fields can be substantially more efficient than might be naively estimated. Such a skin-current heating scheme is analyzed by deriving an equation for diffusion of skin currents into the plasma, from which quantities such as the resistive skin-depth, lumped-circuit impedance, and power deposited in the plasma can be estimated. Numerical estimates indicate that this may be a simple and efficient way to couple power into experiments in this geometry.

  7. Methodology for Augmenting Existing Paths with Additional Parallel Transects

    SciTech Connect (OSTI)

    Wilson, John E.

    2013-09-30

    Visual Sample Plan (VSP) is sample planning software that is used, among other purposes, to plan transect sampling paths to detect areas that were potentially used for munition training. This module was developed for application on a large site where existing roads and trails were to be used as primary sampling paths. Gap areas between these primary paths needed to found and covered with parallel transect paths. These gap areas represent areas on the site that are more than a specified distance from a primary path. These added parallel paths needed to optionally be connected together into a single paththe shortest path possible. The paths also needed to optionally be attached to existing primary paths, again with the shortest possible path. Finally, the process must be repeatable and predictable so that the same inputs (primary paths, specified distance, and path options) will result in the same set of new paths every time. This methodology was developed to meet those specifications.

  8. An extensible operating system design for large-scale parallel machines.

    SciTech Connect (OSTI)

    Riesen, Rolf E.; Ferreira, Kurt Brian

    2009-04-01

    Running untrusted user-level code inside an operating system kernel has been studied in the 1990's but has not really caught on. We believe the time has come to resurrect kernel extensions for operating systems that run on highly-parallel clusters and supercomputers. The reason is that the usage model for these machines differs significantly from a desktop machine or a server. In addition, vendors are starting to add features, such as floating-point accelerators, multicore processors, and reconfigurable compute elements. An operating system for such machines must be adaptable to the requirements of specific applications and provide abstractions to access next-generation hardware features, without sacrificing performance or scalability.

  9. A Study of Successive Over-relaxation Method Parallelization over Modern HPC Languages

    SciTech Connect (OSTI)

    Mittal, Sparsh [ORNL

    2014-01-01

    Successive over-relaxation (SOR) is a computationally intensive, yet extremely important iterative solver for solving linear systems. Due to recent trends of exponential growth in amount of data generated and increasing problem sizes, serial platforms have proved to be insucient in providing the required computational power. In this paper, we present parallel implementations of red-black SOR method using three modern programming languages namely Chapel, D and Go. We employ SOR method for solving 2D steady-state heat conduction problem. We discuss the optimizations incorporated and the features of these languages which are crucial for improving the program performance. Experiments have been performed using 2, 4, and 8 threads and performance results are compared with serial execution. The analysis of results provides important insights into working of SOR method.

  10. Electronically commutated serial-parallel switching for motor windings

    DOE Patents [OSTI]

    Hsu, John S.

    2012-03-27

    A method and a circuit for controlling an ac machine comprises controlling a full bridge network of commutation switches which are connected between a multiphase voltage source and the phase windings to switch the phase windings between a parallel connection and a series connection while providing commutation discharge paths for electrical current resulting from inductance in the phase windings. This provides extra torque for starting a vehicle from lower battery current.

  11. Xyce parallel electronic simulator reference guide, version 6.0.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Schiek, Richard Louis; Thornquist, Heidi K.; Verley, Jason C.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Warrender, Christina E.; Baur, David G.

    2013-08-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide [1] . The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide [1].

  12. Xyce parallel electronic simulator reference guide, version 6.1

    SciTech Connect (OSTI)

    Keiter, Eric R; Mei, Ting; Russo, Thomas V.; Schiek, Richard Louis; Sholander, Peter E.; Thornquist, Heidi K.; Verley, Jason C.; Baur, David Gregory

    2014-03-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide [1] . The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide [1] .

  13. Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers Print Cooling an antiferromagnetic-ferromagnetic bilayer in a magnetic field typically results in a remanent (zero-field) magnetization in the ferromagnet (FM) that is always in the direction of the field during cooling (positive Mrem). Strikingly, when FeF2 is the antiferromagnet (AF), cooling in a field can lead to a remanent magnetization opposite to the field (negative Mrem). A collaboration led by researchers from the Stanford

  14. Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers Print Cooling an antiferromagnetic-ferromagnetic bilayer in a magnetic field typically results in a remanent (zero-field) magnetization in the ferromagnet (FM) that is always in the direction of the field during cooling (positive Mrem). Strikingly, when FeF2 is the antiferromagnet (AF), cooling in a field can lead to a remanent magnetization opposite to the field (negative Mrem). A collaboration led by researchers from the Stanford

  15. Massively Parallel LES of Azimuthal Thermo-Acoustic Instabilities in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Annular Gas Turbines | Argonne Leadership Computing Facility Massively Parallel LES of Azimuthal Thermo-Acoustic Instabilities in Annular Gas Turbines Authors: Wolf, P., Staffelbach, G., Roux, A., Gicquel, L., Poinsot, T., Moureau, V. Increasingly stringent regulations and the need to tackle rising fuel prices have placed great emphasis on the design of aeronautical gas turbines, which are unfortunately more and more prone to combustion instabilities. In the particular field of annular

  16. Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel and Antiparallel Interfacial Coupling in AF-FM Bilayers Print Cooling an antiferromagnetic-ferromagnetic bilayer in a magnetic field typically results in a remanent (zero-field) magnetization in the ferromagnet (FM) that is always in the direction of the field during cooling (positive Mrem). Strikingly, when FeF2 is the antiferromagnet (AF), cooling in a field can lead to a remanent magnetization opposite to the field (negative Mrem). A collaboration led by researchers from the Stanford

  17. Open parabosonic string theory between two parallel Dp-branes

    SciTech Connect (OSTI)

    Hamam, D.; Belaloui, N.

    2012-06-27

    We investigate an open parabosonic string theory between two parallel Dp-branes. The spectrum is constructed and the partition function is derived. A common chord between the development of this latter and the degeneracy of the states for each mass level is obtained. The theory is consistent and with no tachyon. The Virasoro algebra is derived and compared to the one of the ordinary case.

  18. Dynamic and Adaptive Parallel Programming for Exascale Research | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility Sample multi-resolution adaptive decomposition of a function and flow of data associated with compression of the representation. Sample multi-resolution adaptive decomposition of a function and flow of data associated with compression of the representation. The example is in one dimension but practical applications are typically in three, four, five and even six dimensions. Robert Harrison, Stony Brook University Dynamic and Adaptive Parallel Programming for

  19. Dynamic and Adaptive Parallel Programming for Exascale Research | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility calculation A neutron wave-function for a benchmark calculation using a Skyrme functional for the Hartree-Fock-Bogoliubov equation in nuclear physics is solved using an extension of MADNESS, MADNESS-HFB, in coordinate space. Credit: George Fann, Oak Ridge National Laboratory Dynamic and Adaptive Parallel Programming for Exascale Research PI Name: Robert Harrison PI Email: rjharrison@gmail.com Institution: Brookhaven National Laboratory Allocation Program: INCITE

  20. Dynamic and Adaptive Parallel Programming for Exascale Research | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility calculation using a Skyrme functional for the Hartree-Fock-Bogoliubov equation in nuclear physics is solved using an extension of MADNESS, MADNESS-HFB, in coordinate space. George Fann, Oak Ridge National Laboratory Dynamic and Adaptive Parallel Programming for Exascale Research PI Name: Robert Harrison PI Email: rjharrison@gmail.com Institution: Stony Brook University Allocation Program: INCITE Allocation Hours at ALCF: 20 Million Year: 2016 Research Domain:

  1. Xyce Parallel Electronic Simulator : reference guide, version 2.0.

    SciTech Connect (OSTI)

    Hoekstra, Robert John; Waters, Lon J.; Rankin, Eric Lamont; Fixel, Deborah A.; Russo, Thomas V.; Keiter, Eric Richard; Hutchinson, Scott Alan; Pawlowski, Roger Patrick; Wix, Steven D.

    2004-06-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  2. Scalable System Software for Parallel Programming | Argonne Leadership

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computing Facility Streamlines from an early time step of the Rayleigh-Taylor instability depend on scalable storage, communication, and data analysis algorithms developed at extreme scale using INCITE resources. Tom Peterka Scalable System Software for Parallel Programming PI Name: Robert Latham PI Email: robl@mcs.anl.gov Institution: Argonne National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 20 Million Year: 2013 Research Domain: Computer Science The purpose of this

  3. Scalable System Software for Parallel Programming | Argonne Leadership

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computing Facility depend on scalable storage, communication, and data analysis algorithms developed at extreme scale using INCITE resources. Tom Peterka, Argonne National Laboratory Scalable System Software for Parallel Programming PI Name: Robert Latham PI Email: robl@mcs.anl.gov Institution: Argonne National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 25 Million Year: 2014 Research Domain: Computer Science As hardware complexity in Leadership Class Facility systems

  4. Scalable System Software for Parallel Programming | Argonne Leadership

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computing Facility Streamlines from an early time step of the Rayleigh-Taylor instability depend on scalable storage, communication, and data analysis algorithms developed at extreme scale using INCITE resources. Credit: Tom Peterka, Argonne National Laboratory Scalable System Software for Parallel Programming PI Name: Robert Latham PI Email: robl@mcs.anl.gov Institution: Argonne National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 25 Million Year: 2015 Research Domain:

  5. Multithreaded processor architecture for parallel symbolic computation. Technical report

    SciTech Connect (OSTI)

    Fujita, T.

    1987-09-01

    This paper describes the Multilisp Architecture for Symbolic Applications (MASA), which is a multithreaded processor architecture for parallel symbolic computation with various features intended for effective Multilisp program execution. The principal mechanisms exploited for this processor are multiple contexts, interleaved pipeline execution from separate instruction streams, and synchronization based on a bit in each memory cell. The tagged architecture approach is taken for Lisp program execution, and trap conditions are provided for future object manipulation and garbage collection.

  6. Xyce Parallel Electronic Simulator : reference guide, version 4.1.

    SciTech Connect (OSTI)

    Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.; Santarelli, Keith R.; Fixel, Deborah A.; Coffey, Todd Stirling; Russo, Thomas V.; Schiek, Richard Louis; Keiter, Eric Richard; Pawlowski, Roger Patrick

    2009-02-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide.

  7. A Parallel Stochastic Framework for Reservoir Characterization and History Matching

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Thomas, Sunil G.; Klie, Hector M.; Rodriguez, Adolfo A.; Wheeler, Mary F.

    2011-01-01

    The spatial distribution of parameters that characterize the subsurface is never known to any reasonable level of accuracy required to solve the governing PDEs of multiphase flow or species transport through porous media. This paper presents a numerically cheap, yet efficient, accurate and parallel framework to estimate reservoir parameters, for example, medium permeability, using sensor information from measurements of the solution variables such as phase pressures, phase concentrations, fluxes, and seismic and well log data. Numerical results are presented to demonstrate the method.

  8. Parallel Element Agglomeration Algebraic Multigrid and Upscaling Library

    Energy Science and Technology Software Center (OSTI)

    2015-02-19

    ParFELAG is a parallel distributed memory C++ library for numerical upscaling of finite element discretizations. It provides optimal complesity algorithms ro build multilevel hierarchies and solvers that can be used for solving a wide class of partial differential equations (elliptic, hyperbolic, saddle point problems) on general unstructured mesh (under the assumption that the topology of the agglomerated entities is correct). Additionally, a novel multilevel solver for saddle point problems with divergence constraint is implemented.

  9. Gamma ray generator

    DOE Patents [OSTI]

    Firestone, Richard B; Reijonen, Jani

    2014-05-27

    An embodiment of a gamma ray generator includes a neutron generator and a moderator. The moderator is coupled to the neutron generator. The moderator includes a neutron capture material. In operation, the neutron generator produces neutrons and the neutron capture material captures at least some of the neutrons to produces gamma rays. An application of the gamma ray generator is as a source of gamma rays for calibration of gamma ray detectors.

  10. PArallel Reacting Multiphase FLOw Computational Fluid Dynamic Analysis

    Energy Science and Technology Software Center (OSTI)

    2002-06-01

    PARMFLO is a parallel multiphase reacting flow computational fluid dynamics (CFD) code. It can perform steady or unsteady simulations in three space dimensions. It is intended for use in engineering CFD analysis of industrial flow system components. Its parallel processing capabilities allow it to be applied to problems that use at least an order of magnitude more computational cells than the number that can be used on a typical single processor workstation (about 106 cellsmore » in parallel processing mode versus about io cells in serial processing mode). Alternately, by spreading the work of a CFD problem that could be run on a single workstation over a group of computers on a network, it can bring the runtime down by an order of magnitude or more (typically from many days to less than one day). The software was implemented using the industry standard Message-Passing Interface (MPI) and domain decomposition in one spatial direction. The phases of a flow problem may include an ideal gas mixture with an arbitrary number of chemical species, and dispersed droplet and particle phases. Regions of porous media may also be included within the domain. The porous media may be packed beds, foams, or monolith catalyst supports. With these features, the code is especially suited to analysis of mixing of reactants in the inlet chamber of catalytic reactors coupled to computation of product yields that result from the flow of the mixture through the catalyst coaled support structure.« less

  11. Identifying failure in a tree network of a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Pinnow, Kurt W.; Wallenfelt, Brian P.

    2010-08-24

    Methods, parallel computers, and products are provided for identifying failure in a tree network of a parallel computer. The parallel computer includes one or more processing sets including an I/O node and a plurality of compute nodes. For each processing set embodiments include selecting a set of test compute nodes, the test compute nodes being a subset of the compute nodes of the processing set; measuring the performance of the I/O node of the processing set; measuring the performance of the selected set of test compute nodes; calculating a current test value in dependence upon the measured performance of the I/O node of the processing set, the measured performance of the set of test compute nodes, and a predetermined value for I/O node performance; and comparing the current test value with a predetermined tree performance threshold. If the current test value is below the predetermined tree performance threshold, embodiments include selecting another set of test compute nodes. If the current test value is not below the predetermined tree performance threshold, embodiments include selecting from the test compute nodes one or more potential problem nodes and testing individually potential problem nodes and links to potential problem nodes.

  12. Improved parallel solution techniques for the integral transport matrix method

    SciTech Connect (OSTI)

    Zerr, Robert J; Azmy, Yousry Y

    2010-11-23

    Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution by up to {approx}50% when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing case are opticaUy thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block preconditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient preconditioner.

  13. Parallel Computation of the Regional Ocean Modeling System (ROMS)

    SciTech Connect (OSTI)

    Wang, P; Song, Y T; Chao, Y; Zhang, H

    2005-04-05

    The Regional Ocean Modeling System (ROMS) is a regional ocean general circulation modeling system solving the free surface, hydrostatic, primitive equations over varying topography. It is free software distributed world-wide for studying both complex coastal ocean problems and the basin-to-global scale ocean circulation. The original ROMS code could only be run on shared-memory systems. With the increasing need to simulate larger model domains with finer resolutions and on a variety of computer platforms, there is a need in the ocean-modeling community to have a ROMS code that can be run on any parallel computer ranging from 10 to hundreds of processors. Recently, we have explored parallelization for ROMS using the MPI programming model. In this paper, an efficient parallelization strategy for such a large-scale scientific software package, based on an existing shared-memory computing model, is presented. In addition, scientific applications and data-performance issues on a couple of SGI systems, including Columbia, the world's third-fastest supercomputer, are discussed.

  14. Parallel partitioning strategies for the adaptive solution of conservation laws

    SciTech Connect (OSTI)

    Devine, K.D.; Flaherty, J.E.; Loy, R.M.

    1995-12-31

    We describe and examine the performance of adaptive methods for Solving hyperbolic systems of conservation laws on massively parallel computers. The differential system is approximated by a discontinuous Galerkin finite element method with a hierarchical Legendre piecewise polynomial basis for the spatial discretization. Fluxes at element boundaries are computed by solving an approximate Riemann problem; a projection limiter is applied to keep the average solution monotone; time discretization is performed by Runge-Kutta integration; and a p-refinement-based error estimate is used as an enrichment indicator. Adaptive order (p-) and mesh (h-) refinement algorithms are presented and demonstrated. Using an element-based dynamic load balancing algorithm called tiling and adaptive p-refinement, parallel efficiencies of over 60% are achieved on a 1024-processor nCUBE/2 hypercube. We also demonstrate a fast, tree-based parallel partitioning strategy for three-dimensional octree-structured meshes. This method produces partition quality comparable to recursive spectral bisection at a greatly reduced cost.

  15. Design and performance of a scalable, parallel statistics toolkit.

    SciTech Connect (OSTI)

    Thompson, David C.; Bennett, Janine Camille; Pebay, Philippe Pierre

    2010-11-01

    Most statistical software packages implement a broad range of techniques but do so in an ad hoc fashion, leaving users who do not have a broad knowledge of statistics at a disadvantage since they may not understand all the implications of a given analysis or how to test the validity of results. These packages are also largely serial in nature, or target multicore architectures instead of distributed-memory systems, or provide only a small number of statistics in parallel. This paper surveys a collection of parallel implementations of statistics algorithm developed as part of a common framework over the last 3 years. The framework strategically groups modeling techniques with associated verification and validation techniques to make the underlying assumptions of the statistics more clear. Furthermore it employs a design pattern specifically targeted for distributed-memory parallelism, where architectural advances in large-scale high-performance computing have been focused. Moment-based statistics (which include descriptive, correlative, and multicorrelative statistics, principal component analysis (PCA), and k-means statistics) scale nearly linearly with the data set size and number of processes. Entropy-based statistics (which include order and contingency statistics) do not scale well when the data in question is continuous or quasi-diffuse but do scale well when the data is discrete and compact. We confirm and extend our earlier results by now establishing near-optimal scalability with up to 10,000 processes.

  16. Parallel garbage collection without synchronization overhead. Technical report

    SciTech Connect (OSTI)

    Patel, J.H.

    1984-08-01

    Incremental garbage-collection schemes incur substantial overhead that is directly translated as reduced execution efficiency for the user. Parallel garbage-collection schemes implemented via time-slicing on a serial processor also incur this overhead, which might even be aggravated due to context switching. It is useful, therefore, to examine the possibility of implementing a parallel garbage-collection algorithm using a separate processor operating asynchronously with the main-list processor. The overhead in such a scheme arises from the synchronization necessary to manage the two processors, maintaining memory consistency. In this paper, the authors present an architecture and supporting parallel garbage-collection algorithms designed for a virtual memory system with separate processors for list processing and for garbage collection. Each processor has its own primary memory; in addition, there is a small common memory which both processors may access. Individual memories swap off a common secondary memory, but no locking mechanism is required. In particular, a page may reside in both memories simultaneously, and indeed may be accessed and modified freely by each processor. A secondary memory controller ensures consistency without necessitating numerous lockouts on the pages.

  17. Parallel Computing Environments and Methods for Power Distribution System Simulation

    SciTech Connect (OSTI)

    Lu, Ning; Taylor, Zachary T.; Chassin, David P.; Guttromson, Ross T.; Studham, Scott S.

    2005-11-10

    The development of cost-effective high-performance parallel computing on multi-processor super computers makes it attractive to port excessively time consuming simulation software from personal computers (PC) to super computes. The power distribution system simulator (PDSS) takes a bottom-up approach and simulates load at appliance level, where detailed thermal models for appliances are used. This approach works well for a small power distribution system consisting of a few thousand appliances. When the number of appliances increases, the simulation uses up the PC memory and its run time increases to a point where the approach is no longer feasible to model a practical large power distribution system. This paper presents an effort made to port a PC-based power distribution system simulator (PDSS) to a 128-processor shared-memory super computer. The paper offers an overview of the parallel computing environment and a description of the modification made to the PDSS model. The performances of the PDSS running on a standalone PC and on the super computer are compared. Future research direction of utilizing parallel computing in the power distribution system simulation is also addressed.

  18. Automatic Thread-Level Parallelization in the Chombo AMR Library

    SciTech Connect (OSTI)

    Christen, Matthias; Keen, Noel; Ligocki, Terry; Oliker, Leonid; Shalf, John; Van Straalen, Brian; Williams, Samuel

    2011-05-26

    The increasing on-chip parallelism has some substantial implications for HPC applications. Currently, hybrid programming models (typically MPI+OpenMP) are employed for mapping software to the hardware in order to leverage the hardware?s architectural features. In this paper, we present an approach that automatically introduces thread level parallelism into Chombo, a parallel adaptive mesh refinement framework for finite difference type PDE solvers. In Chombo, core algorithms are specified in the ChomboFortran, a macro language extension to F77 that is part of the Chombo framework. This domain-specific language forms an already used target language for an automatic migration of the large number of existing algorithms into a hybrid MPI+OpenMP implementation. It also provides access to the auto-tuning methodology that enables tuning certain aspects of an algorithm to hardware characteristics. Performance measurements are presented for a few of the most relevant kernels with respect to a specific application benchmark using this technique as well as benchmark results for the entire application. The kernel benchmarks show that, using auto-tuning, up to a factor of 11 in performance was gained with 4 threads with respect to the serial reference implementation.

  19. Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-07-07

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  20. Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

    DOE Patents [OSTI]

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-07-14

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  1. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2005-06-14

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  2. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2008-04-22

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  3. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2009-12-29

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  4. Xyce Parallel Electronic Simulator Users Guide Version 6.4

    SciTech Connect (OSTI)

    Keiter, Eric R.; Mei, Ting; Russo, Thomas V.; Schiek, Richard; Sholander, Peter E.; Thornquist, Heidi K.; Verley, Jason; Baur, David Gregory

    2015-12-01

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been de- signed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel com- puting platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to develop new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandia's needs, including some radiation- aware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase -- a message passing parallel implementation -- which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. Trademarks The information herein is subject to change without notice. Copyright c 2002-2015 Sandia Corporation. All rights reserved. Xyce TM Electronic Simulator and Xyce TM are trademarks of Sandia Corporation. Portions of the Xyce TM code are: Copyright c 2002, The Regents of the University of California. Produced at the Lawrence Livermore National Laboratory. Written by Alan Hindmarsh, Allan Taylor, Radu Serban. UCRL-CODE-2002-59 All rights reserved. Orcad, Orcad Capture, PSpice and Probe are

  5. Xyce Parallel Electronic Simulator - Users' Guide Version 2.1.

    SciTech Connect (OSTI)

    Hutchinson, Scott A; Hoekstra, Robert J.; Russo, Thomas V.; Rankin, Eric; Pawlowski, Roger P.; Fixel, Deborah A; Schiek, Richard; Bogdan, Carolyn W.; Shirley, David N.; Campbell, Phillip M.; Keiter, Eric R.

    2005-06-01

    This manual describes the use of theXyceParallel Electronic Simulator.Xycehasbeen designed as a SPICE-compatible, high-performance analog circuit simulator, andhas been written to support the simulation needs of the Sandia National Laboratorieselectrical designers. This development has focused on improving capability over thecurrent state-of-the-art in the following areas:%04Capability to solve extremely large circuit problems by supporting large-scale par-allel computing platforms (up to thousands of processors). Note that this includessupport for most popular parallel and serial computers.%04Improved performance for all numerical kernels (e.g., time integrator, nonlinearand linear solvers) through state-of-the-art algorithms and novel techniques.%04Device models which are specifically tailored to meet Sandia's needs, includingmany radiation-aware devices.3 XyceTMUsers' Guide%04Object-oriented code design and implementation using modern coding practicesthat ensure that theXyceParallel Electronic Simulator will be maintainable andextensible far into the future.Xyceis a parallel code in the most general sense of the phrase - a message passingparallel implementation - which allows it to run efficiently on the widest possible numberof computing platforms. These include serial, shared-memory and distributed-memoryparallel as well as heterogeneous platforms. Careful attention has been paid to thespecific nature of circuit-simulation problems to ensure that optimal parallel efficiencyis achieved as the number of processors grows.The development ofXyceprovides a platform for computational research and de-velopment aimed specifically at the needs of the Laboratory. WithXyce, Sandia hasan %22in-house%22 capability with which both new electrical (e.g., device model develop-ment) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms)research and development can be performed. As a result,Xyceis a unique electricalsimulation capability, designed to

  6. Using Backup Generators: Choosing the Right Backup Generator...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Homeowners Using Backup Generators: Choosing the Right Backup Generator - Homeowners Using Backup Generators: Choosing the Right Backup Generator - Homeowners Determine the amount ...

  7. Power Generation for River and Tidal Generators

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Power Generation for River and Tidal Generators Eduard Muljadi, Alan Wright, and Vahan Gevorgian National Renewable Energy Laboratory James Donegan, Cian Marnagh, and Jarlath McEntee Ocean Renewable Power Company Technical Report NREL/TP-5D00-66097 June 2016 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost from the National Renewable Energy

  8. Requirements for supercomputing in energy research: The transition to massively parallel computing

    SciTech Connect (OSTI)

    Not Available

    1993-02-01

    This report discusses: The emergence of a practical path to TeraFlop computing and beyond; requirements of energy research programs at DOE; implementation: supercomputer production computing environment on massively parallel computers; and implementation: user transition to massively parallel computing.

  9. Optimizing Parallel Access to the BaBar Database System Using...

    Office of Scientific and Technical Information (OSTI)

    Optimizing Parallel Access to the BaBar Database System Using CORBA Servers Citation Details In-Document Search Title: Optimizing Parallel Access to the BaBar Database System Using ...

  10. cray-hdf5-parallel/1.8.13 garbling integers in intel environment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cray-hdf5-parallel1.8.13 garbling integers in intel environment cray-hdf5-parallel1.8.13 garbling integers in intel environment September 11, 2014 This problem was fixed on 11...

  11. BlueGene/L Applications: Parallelism on a Massive Scale (Journal...

    Office of Scientific and Technical Information (OSTI)

    BlueGeneL Applications: Parallelism on a Massive Scale Citation Details In-Document Search Title: BlueGeneL Applications: Parallelism on a Massive Scale You are accessing a ...

  12. Parallel I/O Software Infrastructure for Large-Scale Systems

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Parallel IO Software Infrastructure for Large-Scale Systems Parallel IO Software Infrastructure for Large-Scale Systems Choudhary.png An illustration of how MPI---IO file domain...

  13. Underwater power generator

    SciTech Connect (OSTI)

    Bowley, W.W.

    1983-05-10

    Apparatus and method for generating electrical power by disposing a plurality of power producing modules in a substantially constant velocity ocean current and mechanically coupling the output of the modules to drive a single electrical generator is disclosed.

  14. Quantum random number generator

    DOE Patents [OSTI]

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  15. Final Report: Migration Mechanisms for Large-scale Parallel Applications

    SciTech Connect (OSTI)

    Jason Nieh

    2009-10-30

    Process migration is the ability to transfer a process from one machine to another. It is a useful facility in distributed computing environments, especially as computing devices become more pervasive and Internet access becomes more ubiquitous. The potential benefits of process migration, among others, are fault resilience by migrating processes off of faulty hosts, data access locality by migrating processes closer to the data, better system response time by migrating processes closer to users, dynamic load balancing by migrating processes to less loaded hosts, and improved service availability and administration by migrating processes before host maintenance so that applications can continue to run with minimal downtime. Although process migration provides substantial potential benefits and many approaches have been considered, achieving transparent process migration functionality has been difficult in practice. To address this problem, our work has designed, implemented, and evaluated new and powerful transparent process checkpoint-restart and migration mechanisms for desktop, server, and parallel applications that operate across heterogeneous cluster and mobile computing environments. A key aspect of this work has been to introduce lightweight operating system virtualization to provide processes with private, virtual namespaces that decouple and isolate processes from dependencies on the host operating system instance. This decoupling enables processes to be transparently checkpointed and migrated without modifying, recompiling, or relinking applications or the operating system. Building on this lightweight operating system virtualization approach, we have developed novel technologies that enable (1) coordinated, consistent checkpoint-restart and migration of multiple processes, (2) fast checkpointing of process and file system state to enable restart of multiple parallel execution environments and time travel, (3) process migration across heterogeneous

  16. Time parallelization of advanced operation scenario simulations of ITER plasma

    SciTech Connect (OSTI)

    Samaddar, D.; Casper, T. A.; Kim, S. H.; Berry, Lee A; Elwasif, Wael R; Batchelor, Donald B; Houlberg, Wayne A

    2013-01-01

    This work demonstrates that simulations of advanced burning plasma operation scenarios can be successfully parallelized in time using the parareal algorithm. CORSICA - an advanced operation scenario code for tokamak plasmas is used as a test case. This is a unique application since the parareal algorithm has so far been applied to relatively much simpler systems except for the case of turbulence. In the present application, a computational gain of an order of magnitude has been achieved which is extremely promising. A successful implementation of the Parareal algorithm to codes like CORSICA ushers in the possibility of time efficient simulations of ITER plasmas.

  17. Scripts for Scalable Monitoring of Parallel Filesystem Infrastructure

    Energy Science and Technology Software Center (OSTI)

    2014-02-27

    Scripts for scalable monitoring of parallel filesystem infrastructure provide frameworks for monitoring the health of block storage arrays and large InfiniBand fabrics. The block storage framework uses Python multiprocessing to within scale the number monitored arrays to scale with the number of processors in the system. This enables live monitoring of HPC-scale filesystem with 10-50 storage arrays. For InfiniBand monitoring, there are scripts included that monitor InfiniBand health of each host along with visualization toolsmore » for mapping the topology of complex fabric topologies.« less

  18. Parallel Paradigm for Ultraparallel Multi-Scale Brain Blood Flow

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Simulations | Argonne Leadership Computing Facility Parallel Paradigm for Ultraparallel Multi-Scale Brain Blood Flow Simulations Authors: Grinberg, L., Karniadakis, G.E. In this paper we present one approach in building a scalable solver NekTarG for solution of multi-scale and large size problems [1]. NekTarG has been designed for multi-scale blood modeling. The macro-vascular scales describing the flow dynamics in large vessels are coupled to the mesovascular scales unfolding dynamics of

  19. Implementation of a parallel multilevel secure process. Master's thesis

    SciTech Connect (OSTI)

    Pratt, D.R.

    1988-06-01

    This thesis demonstrates an implementation of a parallel multilevel secure process. This is done within the framework of an electronic-mail system. Security is implemented by GEMSOS, the operating system of the Gemini Trusted Computer Base. A brief history of computer secrecy is followed by a discussion of security kernels. Event counts and sequences are used to provide concurrency control and are covered in detail. The specifications for the system are based upon the requirements for a Headquarters of a hypothetical Marine Battalion in garrison.

  20. Computing NLTE Opacities -- Node Level Parallel Calculation

    SciTech Connect (OSTI)

    Holladay, Daniel

    2015-09-11

    Presentation. The goal: to produce a robust library capable of computing reasonably accurate opacities inline with the assumption of LTE relaxed (non-LTE). Near term: demonstrate acceleration of non-LTE opacity computation. Far term (if funded): connect to application codes with in-line capability and compute opacities. Study science problems. Use efficient algorithms that expose many levels of parallelism and utilize good memory access patterns for use on advanced architectures. Portability to multiple types of hardware including multicore processors, manycore processors such as KNL, GPUs, etc. Easily coupled to radiation hydrodynamics and thermal radiative transfer codes.

  1. Parallel optics technology assessment for the versatile link project

    SciTech Connect (OSTI)

    Chramowicz, J.; Kwan, S.; Rivera, R.; Prosser, A.; /Fermilab

    2011-01-01

    This poster describes the assessment of commercially available and prototype parallel optics modules for possible use as back end components for the Versatile Link common project. The assessment covers SNAP12 transmitter and receiver modules as well as optical engine technologies in dense packaging options. Tests were performed using vendor evaluation boards (SNAP12) as well as custom evaluation boards (optical engines). The measurements obtained were used to compare the performance of these components with single channel SFP+ components operating at a transmission wavelength of 850 nm over multimode fibers.

  2. Scripts for Scalable Monitoring of Parallel Filesystem Infrastructure

    SciTech Connect (OSTI)

    2014-02-27

    Scripts for scalable monitoring of parallel filesystem infrastructure provide frameworks for monitoring the health of block storage arrays and large InfiniBand fabrics. The block storage framework uses Python multiprocessing to within scale the number monitored arrays to scale with the number of processors in the system. This enables live monitoring of HPC-scale filesystem with 10-50 storage arrays. For InfiniBand monitoring, there are scripts included that monitor InfiniBand health of each host along with visualization tools for mapping the topology of complex fabric topologies.

  3. Parallel Computation of Persistent Homology using the Blowup Complex

    SciTech Connect (OSTI)

    Lewis, Ryan; Morozov, Dmitriy

    2015-04-27

    We describe a parallel algorithm that computes persistent homology, an algebraic descriptor of a filtered topological space. Our algorithm is distinguished by operating on a spatial decomposition of the domain, as opposed to a decomposition with respect to the filtration. We rely on a classical construction, called the Mayer--Vietoris blowup complex, to glue global topological information about a space from its disjoint subsets. We introduce an efficient algorithm to perform this gluing operation, which may be of independent interest, and describe how to process the domain hierarchically. We report on a set of experiments that help assess the strengths and identify the limitations of our method.

  4. Routing performance analysis and optimization within a massively parallel computer

    DOE Patents [OSTI]

    Archer, Charles Jens; Peters, Amanda; Pinnow, Kurt Walter; Swartz, Brent Allen

    2013-04-16

    An apparatus, program product and method optimize the operation of a massively parallel computer system by, in part, receiving actual performance data concerning an application executed by the plurality of interconnected nodes, and analyzing the actual performance data to identify an actual performance pattern. A desired performance pattern may be determined for the application, and an algorithm may be selected from among a plurality of algorithms stored within a memory, the algorithm being configured to achieve the desired performance pattern based on the actual performance data.

  5. Local rollback for fault-tolerance in parallel computing systems

    DOE Patents [OSTI]

    Blumrich, Matthias A.; Chen, Dong; Gara, Alan; Giampapa, Mark E.; Heidelberger, Philip; Ohmacht, Martin; Steinmacher-Burow, Burkhard; Sugavanam, Krishnan

    2012-01-24

    A control logic device performs a local rollback in a parallel super computing system. The super computing system includes at least one cache memory device. The control logic device determines a local rollback interval. The control logic device runs at least one instruction in the local rollback interval. The control logic device evaluates whether an unrecoverable condition occurs while running the at least one instruction during the local rollback interval. The control logic device checks whether an error occurs during the local rollback. The control logic device restarts the local rollback interval if the error occurs and the unrecoverable condition does not occur during the local rollback interval.

  6. Performing a global barrier operation in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-12-09

    Executing computing tasks on a parallel computer that includes compute nodes coupled for data communications, where each compute node executes tasks, with one task on each compute node designated as a master task, including: for each task on each compute node until all master tasks have joined a global barrier: determining whether the task is a master task; if the task is not a master task, joining a single local barrier; if the task is a master task, joining the global barrier and the single local barrier only after all other tasks on the compute node have joined the single local barrier.

  7. SERODS optical data storage with parallel signal transfer

    DOE Patents [OSTI]

    Vo-Dinh, Tuan

    2003-09-02

    Surface-enhanced Raman optical data storage (SERODS) systems having increased reading and writing speeds, that is, increased data transfer rates, are disclosed. In the various SERODS read and write systems, the surface-enhanced Raman scattering (SERS) data is written and read using a two-dimensional process called parallel signal transfer (PST). The various embodiments utilize laser light beam excitation of the SERODS medium, optical filtering, beam imaging, and two-dimensional light detection. Two- and three-dimensional SERODS media are utilized. The SERODS write systems employ either a different laser or a different level of laser power.

  8. SERODS optical data storage with parallel signal transfer

    DOE Patents [OSTI]

    Vo-Dinh, Tuan

    2003-06-24

    Surface-enhanced Raman optical data storage (SERODS) systems having increased reading and writing speeds, that is, increased data transfer rates, are disclosed. In the various SERODS read and write systems, the surface-enhanced Raman scattering (SERS) data is written and read using a two-dimensional process called parallel signal transfer (PST). The various embodiments utilize laser light beam excitation of the SERODS medium, optical filtering, beam imaging, and two-dimensional light detection. Two- and three-dimensional SERODS media are utilized. The SERODS write systems employ either a different laser or a different level of laser power.

  9. Digital intermediate frequency QAM modulator using parallel processing

    DOE Patents [OSTI]

    Pao, Hsueh-Yuan; Tran, Binh-Nien

    2008-05-27

    The digital Intermediate Frequency (IF) modulator applies to various modulation types and offers a simple and low cost method to implement a high-speed digital IF modulator using field programmable gate arrays (FPGAs). The architecture eliminates multipliers and sequential processing by storing the pre-computed modulated cosine and sine carriers in ROM look-up-tables (LUTs). The high-speed input data stream is parallel processed using the corresponding LUTs, which reduces the main processing speed, allowing the use of low cost FPGAs.

  10. Motor/generator

    DOE Patents [OSTI]

    Hickam, Christopher Dale

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  11. Solar thermoelectric generator

    DOE Patents [OSTI]

    Toberer, Eric S.; Baranowski, Lauryn L.; Warren, Emily L.

    2016-05-03

    Solar thermoelectric generators (STEGs) are solid state heat engines that generate electricity from concentrated sunlight. A novel detailed balance model for STEGs is provided and applied to both state-of-the-art and idealized materials. STEGs can produce electricity by using sunlight to heat one side of a thermoelectric generator. While concentrated sunlight can be used to achieve extremely high temperatures (and thus improved generator efficiency), the solar absorber also emits a significant amount of black body radiation. This emitted light is the dominant loss mechanism in these generators. In this invention, we propose a solution to this problem that eliminates virtually all of the emitted black body radiation. This enables solar thermoelectric generators to operate at higher efficiency and achieve said efficient with lower levels of optical concentration. The solution is suitable for both single and dual axis solar thermoelectric generators.

  12. Update on Development of Mesh Generation Algorithms in MeshKit

    SciTech Connect (OSTI)

    Jain, Rajeev; Vanderzee, Evan; Mahadevan, Vijay

    2015-09-30

    MeshKit uses a graph-based design for coding all its meshing algorithms, which includes the Reactor Geometry (and mesh) Generation (RGG) algorithms. This report highlights the developmental updates of all the algorithms, results and future work. Parallel versions of algorithms, documentation and performance results are reported. RGG GUI design was updated to incorporate new features requested by the users; boundary layer generation and parallel RGG support were added to the GUI. Key contributions to the release, upgrade and maintenance of other SIGMA1 libraries (CGM and MOAB) were made. Several fundamental meshing algorithms for creating a robust parallel meshing pipeline in MeshKit are under development. Results and current status of automated, open-source and high quality nuclear reactor assembly mesh generation algorithms such as trimesher, quadmesher, interval matching and multi-sweeper are reported.

  13. Tracking the roots of cellulase hyperproduction by the fungus Trichoderma reesei using massively parallel DNA sequencing

    SciTech Connect (OSTI)

    Le Crom, Stphane; Schackwitz, Wendy; Pennacchiod, Len; Magnuson, Jon K.; Culley, David E.; Collett, James R.; Martin, Joel X.; Druzhinina, Irina S.; Mathis, Hugues; Monot, Frdric; Seiboth, Bernhard; Cherry, Barbara; Rey, Michael; Berka, Randy; Kubicek, Christian P.; Baker, Scott E.; Margeot, Antoine

    2009-09-22

    Trichoderma reesei (teleomorph Hypocrea jecorina) is the main industrial source of cellulases and hemicellulases harnessed for the hydrolysis of biomass to simple sugars, which can then be converted to biofuels, such as ethanol, and other chemicals. The highly productive strains in use today were generated by classical mutagenesis. To learn how cellulase production was improved by these techniques, we performed massively parallel sequencing to identify mutations in the genomes of two hyperproducing strains (NG14, and its direct improved descendant, RUT C30). We detected a surprisingly high number of mutagenic events: 223 single nucleotides variants, 15 small deletions or insertions and 18 larger deletions leading to the loss of more than 100 kb of genomic DNA. From these events we report previously undocumented non-synonymous mutations in 43 genes that are mainly involved in nuclear transport, mRNA stability, transcription, secretion/vacuolar targeting, and metabolism. This homogeneity of functional categories suggests that multiple changes are necessary to improve cellulase production and not simply a few clear-cut mutagenic events. Phenotype microarrays show that some of these mutations result in strong changes in the carbon assimilation pattern of the two mutants with respect to the wild type strain QM6a. Our analysis provides the first genome-wide insights into the changes induced by classical mutagenesis in a filamentous fungus, and suggests new areas for the generation of enhanced T. reesei strains for industrial applications such as biofuel production.

  14. Scalable parallel distance field construction for large-scale applications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yu, Hongfeng; Xie, Jinrong; Ma, Kwan -Liu; Kolla, Hemanth; Chen, Jacqueline H.

    2015-10-01

    Computing distance fields is fundamental to many scientific and engineering applications. Distance fields can be used to direct analysis and reduce data. In this paper, we present a highly scalable method for computing 3D distance fields on massively parallel distributed-memory machines. Anew distributed spatial data structure, named parallel distance tree, is introduced to manage the level sets of data and facilitate surface tracking overtime, resulting in significantly reduced computation and communication costs for calculating the distance to the surface of interest from any spatial locations. Our method supports several data types and distance metrics from real-world applications. We demonstrate itsmore » efficiency and scalability on state-of-the-art supercomputers using both large-scale volume datasets and surface models. We also demonstrate in-situ distance field computation on dynamic turbulent flame surfaces for a petascale combustion simulation. In conclusion, our work greatly extends the usability of distance fields for demanding applications.« less

  15. Long-time dynamics through parallel trajectory splicing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Perez, Danny; Cubuk, Ekin D.; Waterland, Amos; Kaxiras, Efthimios; Voter, Arthur F.

    2015-11-24

    Simulating the atomistic evolution of materials over long time scales is a longstanding challenge, especially for complex systems where the distribution of barrier heights is very heterogeneous. Such systems are difficult to investigate using conventional long-time scale techniques, and the fact that they tend to remain trapped in small regions of configuration space for extended periods of time strongly limits the physical insights gained from short simulations. We introduce a novel simulation technique, Parallel Trajectory Splicing (ParSplice), that aims at addressing this problem through the timewise parallelization of long trajectories. The computational efficiency of ParSplice stems from a speculation strategymore » whereby predictions of the future evolution of the system are leveraged to increase the amount of work that can be concurrently performed at any one time, hence improving the scalability of the method. ParSplice is also able to accurately account for, and potentially reuse, a substantial fraction of the computational work invested in the simulation. We validate the method on a simple Ag surface system and demonstrate substantial increases in efficiency compared to previous methods. As a result, we then demonstrate the power of ParSplice through the study of topology changes in Ag42Cu13 core–shell nanoparticles.« less

  16. A Programming Model Performance Study Using the NAS Parallel Benchmarks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shan, Hongzhang; Blagojević, Filip; Min, Seung-Jai; Hargrove, Paul; Jin, Haoqiang; Fuerlinger, Karl; Koniges, Alice; Wright, Nicholas J.

    2010-01-01

    Harnessing the power of multicore platforms is challenging due to the additional levels of parallelism present. In this paper we use the NAS Parallel Benchmarks to study three programming models, MPI, OpenMP and PGAS to understand their performance and memory usage characteristics on current multicore architectures. To understand these characteristics we use the Integrated Performance Monitoring tool and other ways to measure communication versus computation time, as well as the fraction of the run time spent in OpenMP. The benchmarks are run on two different Cray XT5 systems and an Infiniband cluster. Our results show that in general the threemore » programming models exhibit very similar performance characteristics. In a few cases, OpenMP is significantly faster because it explicitly avoids communication. For these particular cases, we were able to re-write the UPC versions and achieve equal performance to OpenMP. Using OpenMP was also the most advantageous in terms of memory usage. Also we compare performance differences between the two Cray systems, which have quad-core and hex-core processors. We show that at scale the performance is almost always slower on the hex-core system because of increased contention for network resources.« less

  17. Perm Web: remote parallel and distributed volume visualization

    SciTech Connect (OSTI)

    Wittenbrink, C.M.; Kim, K.; Story, J.; Pang, A.; Hollerbach, K.; Max, N.

    1997-01-01

    In this paper we present a system for visualizing volume data from remote supercomputers (PermWeb). We have developed both parallel volume rendering algorithms, and the World Wide Web software for accessing the data at the remote sites. The implementation uses Hypertext Markup Language (HTML), Java, and Common Gateway Interface (CGI) scripts to connect World Wide Web (WWW) servers/clients to our volume renderers. The front ends are interactive Java classes for specification of view, shading, and classification inputs. We present performance results, and implementation details for connections to our computing resources at the University of California Santa Cruz including a MasPar MP-2, SGI Reality Engine-RE2, and SGI Challenge machines. We apply the system to the task of visualizing trabecular bone from finite element simulations. Fast volume rendering on remote compute servers through a web interface allows us to increase the accessibility of the results to more users. User interface issues, overviews of parallel algorithm developments, and overall system interfaces and protocols are presented. Access is available through Uniform Resource Locator (URL) http://www.cse.ucsc.edu/research/slvg/. 26 refs., 7 figs.

  18. Efficient VLSI networks for parallel processing based on orthogonal trees

    SciTech Connect (OSTI)

    Nath, D.; Maheshwari, S.N.; Bhatt, P.C.P.

    1983-06-01

    Two interconnection networks for parallel processing, namely the orthogonal trees network and the orthogonal tree cycles (OTN and OTC) are discussed. Both networks are suitable for VLSI implementation and have been analysed using Thompson's model of VLSI. While the OTN and OTC have time performances similar to fast networks such as the perfect shuffle network (PSN), the cube connected cycles (CCC), etc., they have substantially better area* time/sup 2/ performances for a number of matrix and graph problems. For instance, the connected components and a minimal spanning tree of an undirected n-vertex graph can be found in 0(log/sup 4/ n) time on the OTC with an area* time/sup 2/ performance of 0(n/sup 2/ log/sup 8/ n) and 0(n/sup 2/ log/sup 9/ n) respectively. This is asymptotically much better than the performances of the CCC, PSN and MESH. The OTC and OTN can be looked upon as general purpose parallel processors since a number of other problems such as sorting and DFT can be solved on them with an area* time/sup 2/ performance matching that of other networks. Finally, programming the OTN and OTC is simple and they are also amenable to pipelining a series of problems. 33 references.

  19. Nonlinear parallel momentum transport in strong electrostatic turbulence

    SciTech Connect (OSTI)

    Wang, Lu Wen, Tiliang; Diamond, P. H.

    2015-05-15

    Most existing theoretical studies of momentum transport focus on calculating the Reynolds stress based on quasilinear theory, without considering the nonlinear momentum flux-〈v{sup ~}{sub r}n{sup ~}u{sup ~}{sub ∥}〉. However, a recent experiment on TORPEX found that the nonlinear toroidal momentum flux induced by blobs makes a significant contribution as compared to the Reynolds stress [Labit et al., Phys. Plasmas 18, 032308 (2011)]. In this work, the nonlinear parallel momentum flux in strong electrostatic turbulence is calculated by using a three dimensional Hasegawa-Mima equation, which is relevant for tokamak edge turbulence. It is shown that the nonlinear diffusivity is smaller than the quasilinear diffusivity from Reynolds stress. However, the leading order nonlinear residual stress can be comparable to the quasilinear residual stress, and so may be important to intrinsic rotation in tokamak edge plasmas. A key difference from the quasilinear residual stress is that parallel fluctuation spectrum asymmetry is not required for nonlinear residual stress.

  20. Scalable Library for the Parallel Solution of Sparse Linear Systems

    Energy Science and Technology Software Center (OSTI)

    1993-07-14

    BlockSolve is a scalable parallel software library for the solution of large sparse, symmetric systems of linear equations. It runs on a variety of parallel architectures and can easily be ported to others. BlockSovle is primarily intended for the solution of sparse linear systems that arise from physical problems having multiple degrees of freedom at each node point. For example, when the finite element method is used to solve practical problems in structural engineering, eachmore » node will typically have anywhere from 3-6 degrees of freedom associated with it. BlockSolve is written to take advantage of problems of this nature; however, it is still reasonably efficient for problems that have only one degree of freedom associated with each node, such as the three-dimensional Poisson problem. It does not require that the matrices have any particular structure other than being sparse and symmetric. BlockSolve is intended to be used within real application codes. It is designed to work best in the context of our experience which indicated that most application codes solve the same linear systems with several different right-hand sides and/or linear systems with the same structure, but different matrix values multiple times.« less

  1. High-performance parallel interface to synchronous optical network gateway

    DOE Patents [OSTI]

    St. John, Wallace B.; DuBois, David H.

    1996-01-01

    A system of sending and receiving gateways interconnects high speed data interfaces, e.g., HIPPI interfaces, through fiber optic links, e.g., a SONET network. An electronic stripe distributor distributes bytes of data from a first interface at the sending gateway onto parallel fiber optics of the fiber optic link to form transmitted data. An electronic stripe collector receives the transmitted data on the parallel fiber optics and reforms the data into a format effective for input to a second interface at the receiving gateway. Preferably, an error correcting syndrome is constructed at the sending gateway and sent with a data frame so that transmission errors can be detected and corrected in a real-time basis. Since the high speed data interface operates faster than any of the fiber optic links the transmission rate must be adapted to match the available number of fiber optic links so the sending and receiving gateways monitor the availability of fiber links and adjust the data throughput accordingly. In another aspect, the receiving gateway must have sufficient available buffer capacity to accept an incoming data frame. A credit-based flow control system provides for continuously updating the sending gateway on the available buffer capacity at the receiving gateway.

  2. Long-time dynamics through parallel trajectory splicing

    SciTech Connect (OSTI)

    Perez, Danny; Cubuk, Ekin D.; Waterland, Amos; Kaxiras, Efthimios; Voter, Arthur F.

    2015-11-24

    Simulating the atomistic evolution of materials over long time scales is a longstanding challenge, especially for complex systems where the distribution of barrier heights is very heterogeneous. Such systems are difficult to investigate using conventional long-time scale techniques, and the fact that they tend to remain trapped in small regions of configuration space for extended periods of time strongly limits the physical insights gained from short simulations. We introduce a novel simulation technique, Parallel Trajectory Splicing (ParSplice), that aims at addressing this problem through the timewise parallelization of long trajectories. The computational efficiency of ParSplice stems from a speculation strategy whereby predictions of the future evolution of the system are leveraged to increase the amount of work that can be concurrently performed at any one time, hence improving the scalability of the method. ParSplice is also able to accurately account for, and potentially reuse, a substantial fraction of the computational work invested in the simulation. We validate the method on a simple Ag surface system and demonstrate substantial increases in efficiency compared to previous methods. As a result, we then demonstrate the power of ParSplice through the study of topology changes in Ag42Cu13 core–shell nanoparticles.

  3. High-performance parallel interface to synchronous optical network gateway

    DOE Patents [OSTI]

    St. John, W.B.; DuBois, D.H.

    1996-12-03

    Disclosed is a system of sending and receiving gateways interconnects high speed data interfaces, e.g., HIPPI interfaces, through fiber optic links, e.g., a SONET network. An electronic stripe distributor distributes bytes of data from a first interface at the sending gateway onto parallel fiber optics of the fiber optic link to form transmitted data. An electronic stripe collector receives the transmitted data on the parallel fiber optics and reforms the data into a format effective for input to a second interface at the receiving gateway. Preferably, an error correcting syndrome is constructed at the sending gateway and sent with a data frame so that transmission errors can be detected and corrected in a real-time basis. Since the high speed data interface operates faster than any of the fiber optic links the transmission rate must be adapted to match the available number of fiber optic links so the sending and receiving gateways monitor the availability of fiber links and adjust the data throughput accordingly. In another aspect, the receiving gateway must have sufficient available buffer capacity to accept an incoming data frame. A credit-based flow control system provides for continuously updating the sending gateway on the available buffer capacity at the receiving gateway. 7 figs.

  4. Energy Proportionality and Performance in Data Parallel Computing Clusters

    SciTech Connect (OSTI)

    Kim, Jinoh; Chou, Jerry; Rotem, Doron

    2011-02-14

    Energy consumption in datacenters has recently become a major concern due to the rising operational costs andscalability issues. Recent solutions to this problem propose the principle of energy proportionality, i.e., the amount of energy consumedby the server nodes must be proportional to the amount of work performed. For data parallelism and fault tolerancepurposes, most common file systems used in MapReduce-type clusters maintain a set of replicas for each data block. A coveringset is a group of nodes that together contain at least one replica of the data blocks needed for performing computing tasks. In thiswork, we develop and analyze algorithms to maintain energy proportionality by discovering a covering set that minimizesenergy consumption while placing the remaining nodes in lowpower standby mode. Our algorithms can also discover coveringsets in heterogeneous computing environments. In order to allow more data parallelism, we generalize our algorithms so that itcan discover k-covering sets, i.e., a set of nodes that contain at least k replicas of the data blocks. Our experimental results showthat we can achieve substantial energy saving without significant performance loss in diverse cluster configurations and workingenvironments.

  5. RGG: Reactor geometry (and mesh) generator

    SciTech Connect (OSTI)

    Jain, R.; Tautges, T.

    2012-07-01

    The reactor geometry (and mesh) generator RGG takes advantage of information about repeated structures in both assembly and core lattices to simplify the creation of geometry and mesh. It is released as open source software as a part of the MeshKit mesh generation library. The methodology operates in three stages. First, assembly geometry models of various types are generated by a tool called AssyGen. Next, the assembly model or models are meshed by using MeshKit tools or the CUBIT mesh generation tool-kit, optionally based on a journal file output by AssyGen. After one or more assembly model meshes have been constructed, a tool called CoreGen uses a copy/move/merge process to arrange the model meshes into a core model. In this paper, we present the current state of tools and new features in RGG. We also discuss the parallel-enabled CoreGen, which in several cases achieves super-linear speedups since the problems fit in available RAM at higher processor counts. Several RGG applications - 1/6 VHTR model, 1/4 PWR reactor core, and a full-core model for Monju - are reported. (authors)

  6. Tax Credits, Rebates & Savings | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Boilers, Heat Pumps, Programmable Thermostats, Other EE Orcas Power & Light- MORE Green Power Program Incentive payments will be paid per kilowatt hour (kWh) of production,...

  7. NREL: Concentrating Solar Power Research - Southwest Concentrating...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of deployment, combined with research and development to reduce technology component costs, could help reduce concentrating solar power electricity costs to 0.07kilowatt-hour. ...

  8. Tax Credits, Rebates & Savings | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Insulation, Windows, Motor VFDs, Comprehensive MeasuresWhole Building, Other EE Orcas Power & Light- MORE Green Power Program Incentive payments will be paid per kilowatt hour...

  9. Fact Sheet: Accelerating the Development and Deployment of Advanced...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Advanced Technology Vehicles, including Battery Electric and Fuel Cell Electric Vehicles ... draws propulsion energy using a traction battery with at least four kilowatt hours of ...

  10. System Advisor Model (SAM) | Open Energy Information

    Open Energy Info (EERE)

    total electricity production in kilowatt-hours for the first year based on hourly weather data for a particular location, and physical specifications of the power system...

  11. EERE Success Story—Making Wave Power Efficient and Affordable

    Broader source: Energy.gov [DOE]

    Atargis working to demonstrate world's first fully submerged wave energy converter system with 70% efficiency and cost below $0.14 per kilowatt hour.

  12. Table 14a. Average Electricity Prices, Projected vs. Actual

    U.S. Energy Information Administration (EIA) Indexed Site

    a. Average Electricity Prices, Projected vs. Actual" "Projected Price in Constant Dollars" " (constant dollars, cents per kilowatt-hour in ""dollar year"" specific to each AEO)" ...

  13. Aggregating job exit statuses of a plurality of compute nodes executing a parallel application

    DOE Patents [OSTI]

    Aho, Michael E.; Attinella, John E.; Gooding, Thomas M.; Mundy, Michael B.

    2015-07-21

    Aggregating job exit statuses of a plurality of compute nodes executing a parallel application, including: identifying a subset of compute nodes in the parallel computer to execute the parallel application; selecting one compute node in the subset of compute nodes in the parallel computer as a job leader compute node; initiating execution of the parallel application on the subset of compute nodes; receiving an exit status from each compute node in the subset of compute nodes, where the exit status for each compute node includes information describing execution of some portion of the parallel application by the compute node; aggregating each exit status from each compute node in the subset of compute nodes; and sending an aggregated exit status for the subset of compute nodes in the parallel computer.

  14. The parallel I/O architecture of the High Performance Storage System (HPSS)

    SciTech Connect (OSTI)

    Watson, R.W.; Coyne, R.A.

    1995-02-01

    Rapid improvements in computational science, processing capability, main memory sizes, data collection devices, multimedia capabilities and integration of enterprise data are producing very large datasets (10s-100s of gigabytes to terabytes). This rapid growth of data has resulted in a serious imbalance in I/O and storage system performance and functionality. One promising approach to restoring balanced I/O and storage system performance is use of parallel data transfer techniques for client access to storage, device-to-device transfers, and remote file transfers. This paper describes the parallel I/O architecture and mechanisms, Parallel Transport Protocol, parallel FIP, and parallel client Application Programming Interface (API) used by the High Performance Storage System (HPSS). Parallel storage integration issues with a local parallel file system are also discussed.

  15. Quantum random number generation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ma, Xiongfeng; Yuan, Xiao; Cao, Zhu; Zhang, Zhen; Qi, Bing

    2016-06-28

    Here, quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness -- coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at amore » high speed by properly modeling the devices. The second category is self-testing QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semi-self-testing QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.« less

  16. Method of grid generation

    DOE Patents [OSTI]

    Barnette, Daniel W.

    2002-01-01

    The present invention provides a method of grid generation that uses the geometry of the problem space and the governing relations to generate a grid. The method can generate a grid with minimized discretization errors, and with minimal user interaction. The method of the present invention comprises assigning grid cell locations so that, when the governing relations are discretized using the grid, at least some of the discretization errors are substantially zero. Conventional grid generation is driven by the problem space geometry; grid generation according to the present invention is driven by problem space geometry and by governing relations. The present invention accordingly can provide two significant benefits: more efficient and accurate modeling since discretization errors are minimized, and reduced cost grid generation since less human interaction is required.

  17. Steam generator support system

    DOE Patents [OSTI]

    Moldenhauer, James E.

    1987-01-01

    A support system for connection to an outer surface of a J-shaped steam generator for use with a nuclear reactor or other liquid metal cooled power source. The J-shaped steam generator is mounted with the bent portion at the bottom. An arrangement of elongated rod members provides both horizontal and vertical support for the steam generator. The rod members are interconnected to the steam generator assembly and a support structure in a manner which provides for thermal distortion of the steam generator without the transfer of bending moments to the support structure and in a like manner substantially minimizes forces being transferred between the support structure and the steam generator as a result of seismic disturbances.

  18. Steam generator support system

    DOE Patents [OSTI]

    Moldenhauer, J.E.

    1987-08-25

    A support system for connection to an outer surface of a J-shaped steam generator for use with a nuclear reactor or other liquid metal cooled power source is disclosed. The J-shaped steam generator is mounted with the bent portion at the bottom. An arrangement of elongated rod members provides both horizontal and vertical support for the steam generator. The rod members are interconnected to the steam generator assembly and a support structure in a manner which provides for thermal distortion of the steam generator without the transfer of bending moments to the support structure and in a like manner substantially minimizes forces being transferred between the support structure and the steam generator as a result of seismic disturbances. 4 figs.

  19. Generation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Generation Generation Southeastern’s Power Operations employees perform the tasks of declaring, scheduling, dispatching, and accounting for capacity and energy generated at the 22 hydroelectric projects in the agency’s 11-state marketing area. Southeastern has Certified System Operators, meeting the criteria set forth by the North American Electric Reliability Corporation. Southeastern's Power Operations employees perform the tasks of declaring, scheduling, dispatching, and accounting

  20. Distributed generation systems model

    SciTech Connect (OSTI)

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  1. Distributed generation hits market

    SciTech Connect (OSTI)

    1997-10-01

    The pace at which vendors are developing and marketing gas turbines and reciprocating engines for small-scale applications may signal the widespread growth of distributed generation. Loosely defined to refer to applications in which power generation equipment is located close to end users who have near-term power capacity needs, distributed generation encompasses a broad range of technologies and load requirements. Disagreement is inevitable, but many industry observers associate distributed generation with applications anywhere from 25 kW to 25 MW. Ten years ago, distributed generation users only represented about 2% of the world market. Today, that figure has increased to about 4 or 5%, and probably could settle in the 20% range within a 3-to-5-year period, according to Michael Jones, San Diego, Calif.-based Solar Turbines Inc. power generation marketing manager. The US Energy Information Administration predicts about 175 GW of generation capacity will be added domestically by 2010. If 20% comes from smaller plants, distributed generation could account for about 35 GW. Even with more competition, it`s highly unlikely distributed generation will totally replace current market structures and central stations. Distributed generation may be best suited for making market inroads when and where central systems need upgrading, and should prove its worth when the system can`t handle peak demands. Typical applications include small reciprocating engine generators at remote customer sites or larger gas turbines to boost the grid. Additional market opportunities include standby capacity, peak shaving, power quality, cogeneration and capacity rental for immediate demand requirements. Integration of distributed generation systems--using gas-fueled engines, gas-fired combustion engines and fuel cells--can upgrade power quality for customers and reduce operating costs for electric utilities.

  2. Time-Dependent, Parallel Neutral Particle Transport Code System.

    Energy Science and Technology Software Center (OSTI)

    2009-09-10

    Version 00 PARTISN (PARallel, TIme-Dependent SN) is the evolutionary successor to CCC-547/DANTSYS. The PARTISN code package is a modular computer program package designed to solve the time-independent or dependent multigroup discrete ordinates form of the Boltzmann transport equation in several different geometries. The modular construction of the package separates the input processing, the transport equation solving, and the post processing (or edit) functions into distinct code modules: the Input Module, the Solver Module, and themore » Edit Module, respectively. PARTISN is the evolutionary successor to the DANTSYSTM code system package. The Input and Edit Modules in PARTISN are very similar to those in DANTSYS. However, unlike DANTSYS, the Solver Module in PARTISN contains one, two, and three-dimensional solvers in a single module. In addition to the diamond-differencing method, the Solver Module also has Adaptive Weighted Diamond-Differencing (AWDD), Linear Discontinuous (LD), and Exponential Discontinuous (ED) spatial differencing methods. The spatial mesh may consist of either a standard orthogonal mesh or a block adaptive orthogonal mesh. The Solver Module may be run in parallel for two and three dimensional problems. One can now run 1-D problems in parallel using Energy Domain Decomposition (triggered by Block 5 input keyword npeg>0). EDD can also be used in 2-D/3-D with or without our standard Spatial Domain Decomposition. Both the static (fixed source or eigenvalue) and time-dependent forms of the transport equation are solved in forward or adjoint mode. In addition, PARTISN now has a probabilistic mode for Probability of Initiation (static) and Probability of Survival (dynamic) calculations. Vacuum, reflective, periodic, white, or inhomogeneous boundary conditions are solved. General anisotropic scattering and inhomogeneous sources are permitted. PARTISN solves the transport equation on orthogonal (single level or block-structured AMR) grids in 1-D

  3. Adding Data Management Services to Parallel File Systems

    SciTech Connect (OSTI)

    Brandt, Scott

    2015-03-04

    The objective of this project, called DAMASC for “Data Management in Scientific Computing”, is to coalesce data management with parallel file system management to present a declarative interface to scientists for managing, querying, and analyzing extremely large data sets efficiently and predictably. Managing extremely large data sets is a key challenge of exascale computing. The overhead, energy, and cost of moving massive volumes of data demand designs where computation is close to storage. In current architectures, compute/analysis clusters access data in a physically separate parallel file system and largely leave it scientist to reduce data movement. Over the past decades the high-end computing community has adopted middleware with multiple layers of abstractions and specialized file formats such as NetCDF-4 and HDF5. These abstractions provide a limited set of high-level data processing functions, but have inherent functionality and performance limitations: middleware that provides access to the highly structured contents of scientific data files stored in the (unstructured) file systems can only optimize to the extent that file system interfaces permit; the highly structured formats of these files often impedes native file system performance optimizations. We are developing Damasc, an enhanced high-performance file system with native rich data management services. Damasc will enable efficient queries and updates over files stored in their native byte-stream format while retaining the inherent performance of file system data storage via declarative queries and updates over views of underlying files. Damasc has four key benefits for the development of data-intensive scientific code: (1) applications can use important data-management services, such as declarative queries, views, and provenance tracking, that are currently available only within database systems; (2) the use of these services becomes easier, as they are provided within a familiar file

  4. Isolated trigger pulse generator

    DOE Patents [OSTI]

    Aaland, K.

    1980-02-19

    A trigger pulse generation system capable of delivering a multiplicity of isolated 100 kV trigger pulses with picosecond simultaneity. 2 figs.

  5. SNE TRAFIC GENERATOR

    Energy Science and Technology Software Center (OSTI)

    003027MLTPL00 Network Traffic Generator for Low-rate Small Network Equipment Software http://eln.lbl.gov/sne_traffic_gen.html

  6. Renewable Electricity Generation

    SciTech Connect (OSTI)

    2012-09-01

    This document highlights DOE's Office of Energy Efficiency and Renewable Energy's advancements in renewable electricity generation technologies including solar, water, wind, and geothermal.

  7. Talkin Bout Wind Generation

    Office of Energy Efficiency and Renewable Energy (EERE)

    The amount of electricity generated by the wind industry started to grow back around 1999, and since 2007 has been increasing at a rapid pace.

  8. Thermophotovoltaic energy generation

    DOE Patents [OSTI]

    Celanovic, Ivan; Chan, Walker; Bermel, Peter; Yeng, Adrian Y. X.; Marton, Christopher; Ghebrebrhan, Michael; Araghchini, Mohammad; Jensen, Klavs F.; Soljacic, Marin; Joannopoulos, John D.; Johnson, Steven G.; Pilawa-Podgurski, Robert; Fisher, Peter

    2015-08-25

    Inventive systems and methods for the generation of energy using thermophotovoltaic cells are described. Also described are systems and methods for selectively emitting electromagnetic radiation from an emitter for use in thermophotovoltaic energy generation systems. In at least some of the inventive energy generation systems and methods, a voltage applied to the thermophotovoltaic cell (e.g., to enhance the power produced by the cell) can be adjusted to enhance system performance. Certain embodiments of the systems and methods described herein can be used to generate energy relatively efficiently.

  9. Biomass: Biogas Generator

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    BIOGAS GENERATOR Curriculum: Biomass Power (organic chemistry, chemicalcarbon cycles, plants, energy resourcestransformations) Grade Level: Middle School (6-8) Small groups (3 to ...

  10. Isolated trigger pulse generator

    DOE Patents [OSTI]

    Aaland, Kristian (Livermore, CA) [Livermore, CA

    1980-02-19

    A trigger pulse generation system capable of delivering a multiplicity of isolated 100 kV trigger pulses with picosecond simultaneity.

  11. NEGATIVE GATE GENERATOR

    DOE Patents [OSTI]

    Jones, C.S.; Eaton, T.E.

    1958-02-01

    This patent relates to pulse generating circuits and more particularly to rectangular pulse generators. The pulse generator of the present invention incorporates thyratrons as switching elements to discharge a first capacitor through a load resistor to initiate and provide the body of a Pulse, and subsequently dlscharge a second capacitor to impress the potential of its charge, with opposite potential polarity across the load resistor to terminate the pulse. Accurate rectangular pulses in the millimicrosecond range are produced across a low impedance by this generator.

  12. P-SPARSLIB: A parallel sparse iterative solution package

    SciTech Connect (OSTI)

    Saad, Y.

    1994-12-31

    Iterative methods are gaining popularity in engineering and sciences at a time where the computational environment is changing rapidly. P-SPARSLIB is a project to build a software library for sparse matrix computations on parallel computers. The emphasis is on iterative methods and the use of distributed sparse matrices, an extension of the domain decomposition approach to general sparse matrices. One of the goals of this project is to develop a software package geared towards specific applications. For example, the author will test the performance and usefulness of P-SPARSLIB modules on linear systems arising from CFD applications. Equally important is the goal of portability. In the long run, the author wishes to ensure that this package is portable on a variety of platforms, including SIMD environments and shared memory environments.

  13. Synchronizing compute node time bases in a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Faraj, Daniel A; Gooding, Thomas M; Heidelberger, Philip

    2015-01-27

    Synchronizing time bases in a parallel computer that includes compute nodes organized for data communications in a tree network, where one compute node is designated as a root, and, for each compute node: calculating data transmission latency from the root to the compute node; configuring a thread as a pulse waiter; initializing a wakeup unit; and performing a local barrier operation; upon each node completing the local barrier operation, entering, by all compute nodes, a global barrier operation; upon all nodes entering the global barrier operation, sending, to all the compute nodes, a pulse signal; and for each compute node upon receiving the pulse signal: waking, by the wakeup unit, the pulse waiter; setting a time base for the compute node equal to the data transmission latency between the root node and the compute node; and exiting the global barrier operation.

  14. Synchronizing compute node time bases in a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Faraj, Daniel A; Gooding, Thomas M; Heidelberger, Philip

    2014-12-30

    Synchronizing time bases in a parallel computer that includes compute nodes organized for data communications in a tree network, where one compute node is designated as a root, and, for each compute node: calculating data transmission latency from the root to the compute node; configuring a thread as a pulse waiter; initializing a wakeup unit; and performing a local barrier operation; upon each node completing the local barrier operation, entering, by all compute nodes, a global barrier operation; upon all nodes entering the global barrier operation, sending, to all the compute nodes, a pulse signal; and for each compute node upon receiving the pulse signal: waking, by the wakeup unit, the pulse waiter; setting a time base for the compute node equal to the data transmission latency between the root node and the compute node; and exiting the global barrier operation.

  15. Microchannel cross load array with dense parallel input

    DOE Patents [OSTI]

    Swierkowski, Stefan P.

    2004-04-06

    An architecture or layout for microchannel arrays using T or Cross (+) loading for electrophoresis or other injection and separation chemistry that are performed in microfluidic configurations. This architecture enables a very dense layout of arrays of functionally identical shaped channels and it also solves the problem of simultaneously enabling efficient parallel shapes and biasing of the input wells, waste wells, and bias wells at the input end of the separation columns. One T load architecture uses circular holes with common rows, but not columns, which allows the flow paths for each channel to be identical in shape, using multiple mirror image pieces. Another T load architecture enables the access hole array to be formed on a biaxial, collinear grid suitable for EDM micromachining (square holes), with common rows and columns.

  16. Determining collective barrier operation skew in a parallel computer

    SciTech Connect (OSTI)

    Faraj, Daniel A.

    2015-11-24

    Determining collective barrier operation skew in a parallel computer that includes a number of compute nodes organized into an operational group includes: for each of the nodes until each node has been selected as a delayed node: selecting one of the nodes as a delayed node; entering, by each node other than the delayed node, a collective barrier operation; entering, after a delay by the delayed node, the collective barrier operation; receiving an exit signal from a root of the collective barrier operation; and measuring, for the delayed node, a barrier completion time. The barrier operation skew is calculated by: identifying, from the compute nodes' barrier completion times, a maximum barrier completion time and a minimum barrier completion time and calculating the barrier operation skew as the difference of the maximum and the minimum barrier completion time.

  17. DMA shared byte counters in a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Gara, Alan G.; Heidelberger, Philip; Vranas, Pavlos

    2010-04-06

    A parallel computer system is constructed as a network of interconnected compute nodes. Each of the compute nodes includes at least one processor, a memory and a DMA engine. The DMA engine includes a processor interface for interfacing with the at least one processor, DMA logic, a memory interface for interfacing with the memory, a DMA network interface for interfacing with the network, injection and reception byte counters, injection and reception FIFO metadata, and status registers and control registers. The injection FIFOs maintain memory locations of the injection FIFO metadata memory locations including its current head and tail, and the reception FIFOs maintain the reception FIFO metadata memory locations including its current head and tail. The injection byte counters and reception byte counters may be shared between messages.

  18. Nonlocal microscopic theory of quantum friction between parallel metallic slabs

    SciTech Connect (OSTI)

    Despoja, Vito

    2011-05-15

    We present a new derivation of the friction force between two metallic slabs moving with constant relative parallel velocity, based on T=0 quantum-field theory formalism. By including a fully nonlocal description of dynamically screened electron fluctuations in the slab, and avoiding the usual matching-condition procedure, we generalize previous expressions for the friction force, to which our results reduce in the local limit. Analyzing the friction force calculated in the two local models and in the nonlocal theory, we show that for physically relevant velocities local theories using the plasmon and Drude models of dielectric response are inappropriate to describe friction, which is due to excitation of low-energy electron-hole pairs, which are properly included in nonlocal theory. We also show that inclusion of dissipation in the nonlocal electronic response has negligible influence on friction.

  19. Determining collective barrier operation skew in a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A.

    2015-12-24

    Determining collective barrier operation skew in a parallel computer that includes a number of compute nodes organized into an operational group includes: for each of the nodes until each node has been selected as a delayed node: selecting one of the nodes as a delayed node; entering, by each node other than the delayed node, a collective barrier operation; entering, after a delay by the delayed node, the collective barrier operation; receiving an exit signal from a root of the collective barrier operation; and measuring, for the delayed node, a barrier completion time. The barrier operation skew is calculated by: identifying, from the compute nodes' barrier completion times, a maximum barrier completion time and a minimum barrier completion time and calculating the barrier operation skew as the difference of the maximum and the minimum barrier completion time.

  20. Stochastic PArallel Rarefied-gas Time-accurate Analyzer

    Energy Science and Technology Software Center (OSTI)

    2014-01-24

    The SPARTA package is software for simulating low-density fluids via the Direct Simulation Monte Carlo (DSMC) method, which is a particle-based method for tracking particle trajectories and collisions as a model of a multi-species gas. The main component of SPARTA is a simulation code which allows the user to specify a simulation domain, populate it with particles, embed triangulated surfaces as boundary conditions for the flow, overlay a grid for finding pairs of collision partners,more » and evolve the system in time via explicit timestepping. The package also includes various pre- and post-processing tools, useful for setting up simulations and analyzing the results. The simulation code runs either in serial on a single processor or desktop machine, or can be run in parallel using the MPI message-passing library, to enable faster performance on large problems.« less

  1. Design of dynamic load-balancing tools for parallel applications

    SciTech Connect (OSTI)

    Devine, K.D.; Hendrickson, B.A.; Boman, E.G.; St. John, M.; Vaughan, C.T.

    2000-01-03

    The design of general-purpose dynamic load-balancing tools for parallel applications is more challenging than the design of static partitioning tools. Both algorithmic and software engineering issues arise. The authors have addressed many of these issues in the design of the Zoltan dynamic load-balancing library. Zoltan has an object-oriented interface that makes it easy to use and provides separation between the application and the load-balancing algorithms. It contains a suite of dynamic load-balancing algorithms, including both geometric and graph-based algorithms. Its design makes it valuable both as a partitioning tool for a variety of applications and as a research test-bed for new algorithmic development. In this paper, the authors describe Zoltan's design and demonstrate its use in an unstructured-mesh finite element application.

  2. Factorization of large integers on a massively parallel computer

    SciTech Connect (OSTI)

    Davis, J.A.; Holdridge, D.B.

    1988-01-01

    Our interest in integer factorization at Sandia National Laboratories is motivated by cryptographic applications and in particular the security of the RSA encryption-decryption algorithm. We have implemented our version of the quadratic sieve procedure on the NCUBE computer with 1024 processors (nodes). The new code is significantly different in all important aspects from the program used to factor number of order 10/sup 70/ on a single processor CRAY computer. Capabilities of parallel processing and limitation of small local memory necessitated this entirely new implementation. This effort involved several restarts as realizations of program structures that seemed appealing bogged down due to inter-processor communications. We are presently working with integers of magnitude about 10/sup 70/ in tuning this code to the novel hardware. 6 refs., 3 figs.

  3. Optimized collectives using a DMA on a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Gabor, Dozsa; Giampapa, Mark E.; Heidelberger; Phillip

    2011-02-08

    Optimizing collective operations using direct memory access controller on a parallel computer, in one aspect, may comprise establishing a byte counter associated with a direct memory access controller for each submessage in a message. The byte counter includes at least a base address of memory and a byte count associated with a submessage. A byte counter associated with a submessage is monitored to determine whether at least a block of data of the submessage has been received. The block of data has a predetermined size, for example, a number of bytes. The block is processed when the block has been fully received, for example, when the byte count indicates all bytes of the block have been received. The monitoring and processing may continue for all blocks in all submessages in the message.

  4. Toward parallel, adaptive mesh refinement for chemically reacting flow simulations

    SciTech Connect (OSTI)

    Devine, K.D.; Shadid, J.N.; Salinger, A.G. Hutchinson, S.A.; Hennigan, G.L.

    1997-12-01

    Adaptive numerical methods offer greater efficiency than traditional numerical methods by concentrating computational effort in regions of the problem domain where the solution is difficult to obtain. In this paper, the authors describe progress toward adding mesh refinement to MPSalsa, a computer program developed at Sandia National laboratories to solve coupled three-dimensional fluid flow and detailed reaction chemistry systems for modeling chemically reacting flow on large-scale parallel computers. Data structures that support refinement and dynamic load-balancing are discussed. Results using uniform refinement with mesh sequencing to improve convergence to steady-state solutions are also presented. Three examples are presented: a lid driven cavity, a thermal convection flow, and a tilted chemical vapor deposition reactor.

  5. Runtime optimization of an application executing on a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A; Smith, Brian E

    2014-11-25

    Identifying a collective operation within an application executing on a parallel computer; identifying a call site of the collective operation; determining whether the collective operation is root-based; if the collective operation is not root-based: establishing a tuning session and executing the collective operation in the tuning session; if the collective operation is root-based, determining whether all compute nodes executing the application identified the collective operation at the same call site; if all compute nodes identified the collective operation at the same call site, establishing a tuning session and executing the collective operation in the tuning session; and if all compute nodes executing the application did not identify the collective operation at the same call site, executing the collective operation without establishing a tuning session.

  6. Runtime optimization of an application executing on a parallel computer

    DOE Patents [OSTI]

    Faraj, Daniel A; Smith, Brian E

    2014-11-18

    Identifying a collective operation within an application executing on a parallel computer; identifying a call site of the collective operation; determining whether the collective operation is root-based; if the collective operation is not root-based: establishing a tuning session and executing the collective operation in the tuning session; if the collective operation is root-based, determining whether all compute nodes executing the application identified the collective operation at the same call site; if all compute nodes identified the collective operation at the same call site, establishing a tuning session and executing the collective operation in the tuning session; and if all compute nodes executing the application did not identify the collective operation at the same call site, executing the collective operation without establishing a tuning session.

  7. Runtime optimization of an application executing on a parallel computer

    SciTech Connect (OSTI)

    Faraj, Daniel A.; Smith, Brian E.

    2013-01-29

    Identifying a collective operation within an application executing on a parallel computer; identifying a call site of the collective operation; determining whether the collective operation is root-based; if the collective operation is not root-based: establishing a tuning session and executing the collective operation in the tuning session; if the collective operation is root-based, determining whether all compute nodes executing the application identified the collective operation at the same call site; if all compute nodes identified the collective operation at the same call site, establishing a tuning session and executing the collective operation in the tuning session; and if all compute nodes executing the application did not identify the collective operation at the same call site, executing the collective operation without establishing a tuning session.

  8. Tracking moving radar targets with parallel, velocity-tuned filters

    DOE Patents [OSTI]

    Bickel, Douglas L.; Harmony, David W.; Bielek, Timothy P.; Hollowell, Jeff A.; Murray, Margaret S.; Martinez, Ana

    2013-04-30

    Radar data associated with radar illumination of a movable target is processed to monitor motion of the target. A plurality of filter operations are performed in parallel on the radar data so that each filter operation produces target image information. The filter operations are defined to have respectively corresponding velocity ranges that differ from one another. The target image information produced by one of the filter operations represents the target more accurately than the target image information produced by the remainder of the filter operations when a current velocity of the target is within the velocity range associated with the one filter operation. In response to the current velocity of the target being within the velocity range associated with the one filter operation, motion of the target is tracked based on the target image information produced by the one filter operation.

  9. Final Report: Super Instruction Architecture for Scalable Parallel Computations

    SciTech Connect (OSTI)

    Sanders, Beverly Ann; Bartlett, Rodney; Deumens, Erik

    2013-12-23

    The most advanced methods for reliable and accurate computation of the electronic structure of molecular and nano systems are the coupled-cluster techniques. These high-accuracy methods help us to understand, for example, how biological enzymes operate and contribute to the design of new organic explosives. The ACES III software provides a modern, high-performance implementation of these methods optimized for high performance parallel computer systems, ranging from small clusters typical in individual research groups, through larger clusters available in campus and regional computer centers, all the way to high-end petascale systems at national labs, including exploiting GPUs if available. This project enhanced the ACESIII software package and used it to study interesting scientific problems.

  10. Development of parallel DEM for the open source code MFIX

    SciTech Connect (OSTI)

    Gopalakrishnan, Pradeep; Tafti, Danesh

    2013-02-01

    The paper presents the development of a parallel Discrete Element Method (DEM) solver for the open source code, Multiphase Flow with Interphase eXchange (MFIX) based on the domain decomposition method. The performance of the code was evaluated by simulating a bubbling fluidized bed with 2.5 million particles. The DEM solver shows strong scalability up to 256 processors with an efficiency of 81%. Further, to analyze weak scaling, the static height of the fluidized bed was increased to hold 5 and 10 million particles. The results show that global communication cost increases with problem size while the computational cost remains constant. Further, the effects of static bed height on the bubble hydrodynamics and mixing characteristics are analyzed.

  11. Parallel Access of Out-Of-Core Dense Extendible Arrays

    SciTech Connect (OSTI)

    Otoo, Ekow J; Rotem, Doron

    2007-07-26

    Datasets used in scientific and engineering applications are often modeled as dense multi-dimensional arrays. For very large datasets, the corresponding array models are typically stored out-of-core as array files. The array elements are mapped onto linear consecutive locations that correspond to the linear ordering of the multi-dimensional indices. Two conventional mappings used are the row-major order and the column-major order of multi-dimensional arrays. Such conventional mappings of dense array files highly limit the performance of applications and the extendibility of the dataset. Firstly, an array file that is organized in say row-major order causes applications that subsequently access the data in column-major order, to have abysmal performance. Secondly, any subsequent expansion of the array file is limited to only one dimension. Expansions of such out-of-core conventional arrays along arbitrary dimensions, require storage reorganization that can be very expensive. Wepresent a solution for storing out-of-core dense extendible arrays that resolve the two limitations. The method uses a mapping function F*(), together with information maintained in axial vectors, to compute the linear address of an extendible array element when passed its k-dimensional index. We also give the inverse function, F-1*() for deriving the k-dimensional index when given the linear address. We show how the mapping function, in combination with MPI-IO and a parallel file system, allows for the growth of the extendible array without reorganization and no significant performance degradation of applications accessing elements in any desired order. We give methods for reading and writing sub-arrays into and out of parallel applications that run on a cluster of workstations. The axial-vectors are replicated and maintained in each node that accesses sub-array elements.

  12. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

    1994-01-01

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

  13. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

    1993-01-01

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

  14. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  15. Improved solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  16. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  17. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1994-02-15

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus is described. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 7 figures.

  18. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1993-12-28

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 11 figures.

  19. Internal split field generator

    DOE Patents [OSTI]

    Thundat; Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-01-03

    A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.

  20. Geothermal Generation | Open Energy Information

    Open Energy Info (EERE)

    Geothermal Generation This article is a stub. You can help OpenEI by expanding it. Global Geothermal Energy Generation Global Geothermal Electricity Generation in 2007 (in millions...