Powered by Deep Web Technologies
Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Beating the One-half Limit of Ancilla-free Linear Optics Bell Measurements  

E-Print Network (OSTI)

We show that optically encoded two-qubit Bell states can be unambiguously discriminated with a success probability of more than 50% in both single-rail and dual-rail encodings by using active linear-optical resources that include Gaussian squeezing operations. These results are in contrast to the well-known upper bound of 50% for unambiguous discrimination of dual-rail Bell states using passive, static linear optics and arbitrarily many vacuum modes. We present experimentally feasible schemes that improve the success probability to 64.3% in dual-rail and to 62.5% in single-rail for a uniform random distribution of Bell states. Conceptually, this demonstrates that neither interactions that induce nonlinear mode transformations (such as Kerr interactions) nor auxiliary entangled photons are required to go beyond the one-half limit. We discuss the optimality of our single-rail scheme, and talk about an application of our dual-rail scheme in quantum communication.

Hussain A. Zaidi; Peter van Loock

2013-01-13T23:59:59.000Z

2

hourly | OpenEI  

Open Energy Info (EERE)

hourly hourly Dataset Summary Description This dataset contains hourly load profile data for 16 commercial building types (based off the DOE commercial reference building models) and residential buildings (based off the Building America House Simulation Protocols). This dataset also includes the Residential Energy Consumption Survey (RECS) for statistical references of building types by location. Source Commercial and Residential Reference Building Models Date Released April 18th, 2013 (7 months ago) Date Updated July 02nd, 2013 (5 months ago) Keywords building building demand building load Commercial data demand Energy Consumption energy data hourly kWh load profiles Residential Data Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually

3

Approximate diagonalization  

E-Print Network (OSTI)

Abstract. We describe a new method of computing functions of highly non-normal matrices, by using the concept of approximate diagonalization. We formulate a conjecture about its efficiency, and provide both theoretical and numerical evidence in support of the conjecture. We apply the method to compute arbitrary real powers of highly non-normal matrices. Key words. Jordan matrices, ill-posedness, regularization, fractional powers, functional calculus, spectral theory.

E B Davies

2007-01-01T23:59:59.000Z

4

NERSC Edison Hours Used Report  

NLE Websites -- All DOE Office Websites (Extended Search)

Edison Hours Used Edison Hours Used Edison Usage Chart Edison Usage Chart Date Hours Used (in millions) Percent of Maximum Possible (24 hoursday) 10142013 1.852 61.8 10132013...

5

OpenEI - hourly data  

Open Energy Info (EERE)

http:en.openei.orgdatasetstaxonomyterm4980 en Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and diffuse) data for selected stations in Sri Lanka from...

6

Transitioning to 12-hour shifts  

Science Conference Proceedings (OSTI)

In 1989, Yankee Rowe nuclear power station successfully implemented a 12-hour shift schedule for all shiftworkers (control room personnel, auxiliary operators, and radiation protection shift technicians) with many positive effects on morale, motivation, and performance. The transition from an 8-hour to a 12-hour shift schedule was initiated, organized, and promoted by the shiftworkers themselves after they had identified numerous inadequacies in the 8-hour shift schedule. Preliminary and final implementation required several steps: (a) a survey of needs, (b) research of potential schedules, (c) cost/benefit analysis, (d) resolution of any union contract conflicts, (e) management approval, and (f) trial shift schedule periods.

Suter, P.S.; Cervassi, S.M.

1993-03-01T23:59:59.000Z

7

NERSC Franklin Hours Used Report  

NLE Websites -- All DOE Office Websites (Extended Search)

Franklin Hours Used Franklin Hours Used Franklin Hours Used 2011 Franklin Usage in Hours 2011 Franklin Usage in Hours 2010 2010 Franklin Usage in Hours 2009 2009 Franklin Usage in Hours 2007-2008 2008 Franklin Usage in Hours 2008 Franklin Usage in Hours Date Hours Used (in thousands) Percentage of Maximum Possible (24 hours/day) 04/28/2012 0.00 0.00 04/27/2012 272.62 29.40 04/26/2012 692.81 74.71 04/25/2012 841.60 90.75 04/24/2012 53.86 5.81 04/23/2012 432.01 46.59 04/22/2012 823.23 88.77 04/21/2012 473.95 51.11 04/20/2012 173.75 18.74 04/19/2012 449.22 48.44 04/18/2012 816.23 88.02 04/17/2012 754.35 81.34 04/16/2012 648.89 69.97 04/15/2012 812.25 87.59 04/14/2012 843.46 90.95 04/13/2012 737.46 79.52 04/12/2012 711.97 76.77 04/11/2012 734.65 79.22 04/10/2012 815.65 87.95 04/09/2012 897.25 96.75

8

Teach Yourself in 24 Hours  

E-Print Network (OSTI)

"ations .................................................. 302 Reclaiming Memory with the kill Command .................................. 303 Getting System Load in a retrieval system, or transmitted by any means, electronic, mechanical, photo- copying, recording 1 Hour 1 Preparing to Install Linux 3 2 Installing Linux 11 3 Configuring the X Window System 31

Eckmiller, Rolf

9

NERSC Carver Hours Used Report  

NLE Websites -- All DOE Office Websites (Extended Search)

Carver Hours Carver Hours Used Carver Hours Used Hopper Usage Chart Hopper Usage Chart Date Hours Used (in millions) Percent of Maximum Possible (24 hours/day) 01/05/2014 170.00 89.35 01/04/2014 174.38 91.65 01/03/2014 174.15 91.53 01/02/2014 179.72 94.45 01/01/2014 173.76 91.32 12/31/2013 172.25 90.53 12/30/2013 169.62 89.14 12/29/2013 164.72 86.57 12/28/2013 177.92 93.51 12/27/2013 171.61 90.19 12/26/2013 172.74 90.79 12/25/2013 172.13 90.46 12/24/2013 173.48 91.18 12/23/2013 174.92 91.93 12/22/2013 175.26 92.11 12/21/2013 173.58 91.23 12/20/2013 174.50 91.71 12/19/2013 170.02 89.36 12/18/2013 178.25 93.68 12/17/2013 176.17 92.59 12/16/2013 162.03 85.16 12/15/2013 157.09 82.56 12/14/2013 173.40 91.13 12/13/2013 185.02 97.24 12/12/2013 150.91 79.31 12/11/2013 31.67 16.64 12/10/2013 92.44 48.58

10

hourly data | OpenEI  

Open Energy Info (EERE)

data data Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. Source U.S. National Renewable Energy Laboratory (NREL) Date Released May 03rd, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DNI GHI hourly data NREL solar Sri Lanka SWERA TILT TMY UNEP Data application/zip icon Download TMY data (zip, 67.5 MiB)

11

Predicting hourly building energy usage  

SciTech Connect

This article presents the results of an evaluation to identify the most accurate method for making hourly energy use predictions. The prediction of energy usage by HVAC systems is important for the purposes of HVAC diagnostics, system control, parameter and system identification, optimization and energy management. Many new techniques are now being applied to the analysis problems involved with predicting the future behavior of HVAC systems and deducing properties of these systems. Similar problems arise in most observational disciplines, including physics, biology and economics.

Kreider, J.F. (Univ. of Colorado, Boulder, CO (United States). Dept. of Civil, Environmental and Architectural Engineering); Haberl, J.S. (Texas A and M Univ., College Station, TX (United States). Mechanical Engineering Dept.)

1994-06-01T23:59:59.000Z

12

Estimation of Daily Degree-hours  

Science Conference Proceedings (OSTI)

Degree-hours have many applications in fields such as agriculture, architecture, and power generation. Since daily mean temperatures are more readily available than hourly temperatures, the difference between mean daily degree-hours computed from ...

Nathaniel B. Guttman; Richard L. Lehman

1992-07-01T23:59:59.000Z

13

DOE Awards Over a Billion Supercomputing Hours to Address Scientific  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Over a Billion Supercomputing Hours to Address Over a Billion Supercomputing Hours to Address Scientific Challenges DOE Awards Over a Billion Supercomputing Hours to Address Scientific Challenges January 26, 2010 - 12:00am Addthis Washington, DC. - The U.S. Department of Energy announced today that approximately 1.6 billion supercomputing processor hours have been awarded to 69 cutting-edge research projects through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. The INCITE program provides powerful resources to enable scientists and engineers to conduct cutting-edge research in just weeks or months rather than the years or decades needed previously. This facilitates scientific breakthroughs in areas such as climate change, alternative energy, life sciences, and materials science.

14

DOE Awards Over a Billion Supercomputing Hours to Address Scientific  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Awards Over a Billion Supercomputing Hours to Address DOE Awards Over a Billion Supercomputing Hours to Address Scientific Challenges DOE Awards Over a Billion Supercomputing Hours to Address Scientific Challenges January 26, 2010 - 12:00am Addthis Washington, DC. - The U.S. Department of Energy announced today that approximately 1.6 billion supercomputing processor hours have been awarded to 69 cutting-edge research projects through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. The INCITE program provides powerful resources to enable scientists and engineers to conduct cutting-edge research in just weeks or months rather than the years or decades needed previously. This facilitates scientific breakthroughs in areas such as climate change, alternative energy, life

15

Definition: Kilowatt-hour | Open Energy Information  

Open Energy Info (EERE)

Kilowatt-hour Kilowatt-hour Jump to: navigation, search Dictionary.png Kilowatt-hour A unit of measure for energy, typically applied to electricity usage; equal to the amount of energy used at a rate of 1,000 watts over the course of one hour. One kWh is equivalent to 3,412 Btu, or 3,600 kJ.[1][2] View on Wikipedia Wikipedia Definition The kilowatt hour, or kilowatt-hour, (symbol kW·h, kW h or kWh) is a unit of energy equal to 1000 watt hours or 3.6 megajoules. For constant power, energy in watt hours is the product of power in watts and time in hours. The kilowatt hour is most commonly known as a billing unit for energy delivered to consumers by electric utilities. Also Known As kWh Related Terms British thermal unit, Electricity, Energy, Kilowatt, energy, electricity generation

16

Facility location: distributed approximation  

Science Conference Proceedings (OSTI)

In this paper, we initiate the study of the approximability of the facility location problem in a distributed setting. In particular, we explore a trade-off between the amount of communication and the resulting approximation ratio. We give a distributed ... Keywords: distributed approximation, facility location, linear programming, primal-dual algorithms

Thomas Moscibroda; Rogert Wattenhofer

2005-07-01T23:59:59.000Z

17

Approximation of Stochastic Process  

E-Print Network (OSTI)

May 8, 2012 ... The approximation of stochastic processes by trees is an important topic in ... process ? is replaced by a finitely valued stochastic scenario ...

18

The Autocorrelation of Hourly Wind Speed Observations  

Science Conference Proceedings (OSTI)

The autocorrelation of hourly wind speed observations is estimated for seven stations on the west coast of Canada at selected lags ranging from one hour to two months. The estimated autocorrelation function is fitted by a model that includes a ...

Arthur C. Brett; Stanton E. Tuller

1991-06-01T23:59:59.000Z

19

Virtualizing office hours in CS 50  

Science Conference Proceedings (OSTI)

In Fall 2007, we introduced "virtual office hours" into Harvard College's introductory computer science course, CS 50, so that students could meet with teaching fellows (TFs) online to discuss problem sets at any hour from anywhere. Our goals were to ... Keywords: CSCW, collaboration, distance education, virtual office hours

David J. Malan

2009-07-01T23:59:59.000Z

20

delta-Approximable Functions  

Science Conference Proceedings (OSTI)

In this paper we study several notions of approximability of functions in the framework of the BSS model. Denoting with ¿¿M the function computed by a BSS machine M when its comparisons are against -¿ rather than 0, we study ...

Charles Meyssonnier; Paolo Boldi; Sebastiano Vigna

2000-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

OpenEI - hourly emission factors  

Open Energy Info (EERE)

http:en.openei.orgdatasetstaxonomyterm4640 en Hourly Energy Emission Factors for Electricity Generation in the United States http:en.openei.orgdatasetsnode488...

22

Storing hydroelectricity to meet peak-hour demand  

Science Conference Proceedings (OSTI)

This paper reports on pumped storage plants which have become an effective way for some utility companies that derive power from hydroelectric facilities to economically store baseload energy during off-peak hours for use during peak hourly demands. According to the Electric Power Research Institute (EPRI) in Palo Alto, Calif., 36 of these plants provide approximately 20 gigawatts, or about 3 percent of U.S. generating capacity. During peak-demand periods, utilities are often stretched beyond their capacity to provide power and must therefore purchase it from neighboring utilities. Building new baseload power plants, typically nuclear or coal-fired facilities that run 24 hours per day seven days a week, is expensive, about $1500 per kilowatt, according to Robert Schainker, program manager for energy storage at the EPRI. Schainker the that building peaking plants at $400 per kilowatt, which run a few hours a day on gas or oil fuel, is less costly than building baseload plants. Operating them, however, is more expensive because peaking plants are less efficient that baseload plants.

Valenti, M.

1992-04-01T23:59:59.000Z

23

Impact of Wind Energy on Hourly Load Following Requirements: An Hourly and Seasonal Analysis; Preprint  

Science Conference Proceedings (OSTI)

The impacts of wind energy on the power system grid can be decomposed into several time scales that include regulation, load following, and unit commitment. Techniques for evaluating the impacts on these time scales are still evolving, and as wind energy becomes a larger part of the electricity supply, valuable experience will be gained that will help refine these methods. Studies that estimated the impact of wind in the load following time scale found differing results and costs, ranging from near zero to approximately $2.50/megawatt-hour (MWh). Part of the reason for these differences is the different interpretation of the impacts that would be allocated to this ancillary service. Because of the low correlation between changes in load and wind, long-term analyses of the load following impact of wind may find low impacts. During the daily load cycle, there is a tremendous variability in load following requirements in systems without wind. When significant levels of wind generation are added to the resource mix, relatively small changes in wind output can complicate the task of balancing the system during periods of large load swings. This paper analyzes the load following impacts of wind by segregating these critical time periods of the day and separating the analysis by season. The analysis compares wind generation at geographically dispersed sites to wind generation based primarily at a single site, and for a large penetration of wind (more than 20% wind capacity to peak load).

Krich, A.; Milligan, M.

2005-05-01T23:59:59.000Z

24

Bradbury Science Museum announces winter opening hours  

NLE Websites -- All DOE Office Websites (Extended Search)

Bradbury Science Museum winter hours Bradbury Science Museum winter hours Bradbury Science Museum announces winter opening hours Museum will be closed on Christmas Day (December 25) and New Year's Day (January 1, 2011). December 21, 2010 Bradbury Science Museum Bradbury Science Museum Contact Communications Office (505) 667-7000 Often called "a window to the Laboratory," the museum annually attracts thousands of visitors from all over the world. LOS ALAMOS, New Mexico, December 21, 2010-Los Alamos National Laboratory's Bradbury Science Museum will be closed on Christmas Day (December 25) and New Year's Day (January 1, 2011). On all other days, the museum will observe regular opening hours: from 10 a.m. to 5 p.m. Tuesdays to Saturdays, and from 1 to 5 p.m. Sundays and Mondays. Often called "a window to the Laboratory," the museum annually attracts

25

hourly solar radiation | OpenEI  

Open Energy Info (EERE)

solar radiation solar radiation Dataset Summary Description (Abstract): A need for predicting hourly global radiation exists for many locations particularly in Bangladesh for which measured values are not available and daily values have to be estimated from sunshine data. The CPRG model has been used to predict values of hourly Gh for Dhaka (23.770N, 90.380E), Chittagong (22.270N, 91.820E) and Bogra (24.850N, 89.370E) for = ±7.50, ±22.50, ±37.50, ±52.50, ±67.50, ±82.50 and ±97.50 i.e., for ±1/2, ±3/2, ±5/2, ±7/2, ±9/2, ±11/2, ±13/2 hours before and after solar noon and the computed values for Source Renewable Energy Research Centre Date Released October 22nd, 2003 (11 years ago) Date Updated Unknown Keywords Bangladesh documentation hourly solar radiation SWERA

26

Life of a Six-Hour Hurricane  

Science Conference Proceedings (OSTI)

Hurricane Claudette developed from a weak vortex in 6 h as deep convection shifted from downshear into the vortex center, despite ambient vertical wind shear exceeding 10 m s?1. Six hours later it weakened to a tropical storm, and 12 h after the ...

Kay L. Shelton; John Molinari

2009-01-01T23:59:59.000Z

27

NERSC Edison Phase I Hours Used Report  

NLE Websites -- All DOE Office Websites (Extended Search)

Edison Phase I Hours Used Edison Phase I Hours Used Edison Phase I Hours Used Edison Usage Chart Edison Usage Chart Date Hours Used (in millions) Percent of Maximum Possible (24 hours/day) 06/23/2013 0.226 88.6 06/22/2013 0.239 93.9 06/21/2013 0.248 97.1 06/20/2013 0.240 94.0 06/19/2013 0.233 91.3 06/18/2013 0.245 96.0 06/17/2013 0.251 98.4 06/16/2013 0.243 95.3 06/15/2013 0.245 95.9 06/14/2013 0.246 96.5 06/13/2013 0.240 94.1 06/12/2013 0.128 50.4 06/11/2013 0.215 84.5 06/10/2013 0.225 88.4 06/09/2013 0.228 89.6 06/08/2013 0.225 88.3 06/07/2013 0.121 47.5 06/06/2013 0.223 87.4 06/05/2013 0.250 98.0 06/04/2013 0.234 91.6 06/03/2013 0.218 85.5 06/02/2013 0.246 96.4 06/01/2013 0.230 90.0 05/31/2013 0.215 84.5 05/30/2013 0.212 83.1 05/29/2013 0.223 87.3 05/28/2013 0.237 93.0 05/27/2013 0.226 88.5 05/26/2013 0.229 89.9

28

Hour-by-Hour Cost Modeling of Optimized Central Wind-Based Water Electrolysis Production  

NLE Websites -- All DOE Office Websites (Extended Search)

Hour-by-Hour Cost Hour-by-Hour Cost Modeling of Optimized Central Wind-Based Water Electrolysis Production Genevieve Saur (PI), Chris Ainscough (Presenter), Kevin Harrison, Todd Ramsden National Renewable Energy Laboratory January 17 th , 2013 This presentation does not contain any proprietary, confidential, or otherwise restricted information 2 Acknowledgements * This work was made possible by support from the U.S. Department of Energy's Fuel Cell Technologies Office within the Office of Energy Efficiency and Renewable Energy (EERE). http://www.eere.energy.gov/topics/hydrogen_fuel_cells.html * NREL would like to thank our DOE Technology Development Managers for this project, Sara Dillich, Eric Miller, Erika Sutherland, and David Peterson. * NREL would also like to acknowledge the indirect

29

What do hourly performance data on a building tell us  

DOE Green Energy (OSTI)

Hourly performance data on a building contain valuable information on the dynamics of the building and of the HVAC systems. Quantities such as the building loss coefficient, solar gains, and the net effect of thermal masses and their couplings are all contained in the data. The building element vector analysis (BEVA) method has been applied to a multizone residential passive solar building monitored under the SERI Class B program. Using short-term data (approximately one week), the building parameters were regressed. With these as inputs, the subsequent performance of the building was well predicted. Using performance data for the period February 3-9, 1982, the building vectors were obtained by regression. The resulting best fit for the zone temperature is given. These parameters were used to predict the temperature for the period February 10-14. The resulting values are also plotted along with the outdoor temperature, solar radiation on a south vertical surface, and auxiliary energy for these periods.

Subbarao, K.

1984-11-01T23:59:59.000Z

30

DOE Awards Over a Billion Supercomputing Hours to Address Scientific...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Over a Billion Supercomputing Hours to Address Scientific Challenges DOE Awards Over a Billion Supercomputing Hours to Address Scientific Challenges January 26, 2010 - 12:00am...

31

DOE's Office of Science Awards 95 Million Hours of Supercomputing...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

95 Million Hours of Supercomputing Time to Advance Research in Science, Academia and Industry DOE's Office of Science Awards 95 Million Hours of Supercomputing Time to Advance...

32

Scaled hydrogenic approximation wavefunctions. [Hartree-Fock approximation  

DOE Green Energy (OSTI)

Although widespread use of computer codes for the solution of Schrodinger equations makes available numerical Hartree-Fock model radial wave functions, there remains persistant interest in simple analytic expressions for atomic wave functions. One such frequency favored approach employs hydrogenic functions, suitably scaled, as approximate wave functions. The following note displays typical inaccuracies to be expected from such approximations. 13 references.

Shore, B.W.

1979-09-01T23:59:59.000Z

33

hourly emission factors | OpenEI  

Open Energy Info (EERE)

60 60 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278660 Varnish cache server hourly emission factors Dataset Summary Description Emissions from energy use in buildings are usually estimated on an annual basis using annual average multipliers. Using annual numbers provides a reasonable estimation of emissions, but it provides no indication of the temporal nature of the emissions. Therefore, there is no way of understanding the impact on emissions from load shifting and peak shaving technologies such as thermal energy storage, on-site renewable energy, and demand control. Source NREL Date Released April 11th, 2011 (3 years ago) Date Updated April 11th, 2011 (3 years ago)

34

On the Beta Plane Approximation  

Science Conference Proceedings (OSTI)

The beta plane approximation as it is usually derived suffers from the difficulty that it is only valid if the quasi-geostrophic approximation is made. It is not valid for the underlying momentum and continuity equations. The problem in the ...

W. T. M. Verkley

1990-10-01T23:59:59.000Z

35

Commercial and Residential Hourly Load Profiles for all TMY3 Locations in  

Open Energy Info (EERE)

and Residential Hourly Load Profiles for all TMY3 Locations in and Residential Hourly Load Profiles for all TMY3 Locations in the United States Dataset Summary Description This dataset contains hourly load profile data for 16 commercial building types (based off the DOE commercial reference building models) and residential buildings (based off the Building America House Simulation Protocols). This dataset also includes the Residential Energy Consumption Survey (RECS) for statistical references of building types by location. Hourly load profiles are available for over all TMY3 locations in the United States here. Browse files in this dataset, accessible as individual files and as commercial and residential downloadable ZIP files. This dataset is approximately 4.8GiB compressed or 19GiB uncompressed. July 2nd, 2013 update: Residential High and Low load files have been updated from 366 days in a year for leap years to the more general 365 days in a normal year.

36

The Subinertial Mixed Layer Approximation  

Science Conference Proceedings (OSTI)

The density of the mixed layer is approximately uniform in the vertical but has dynamically important horizontal gradients. These nonuniformities in density result in a vertically sheared horizontal pressure gradient. Subinertial motions balance ...

W. R. Young

1994-08-01T23:59:59.000Z

37

The Quasi-Hydrostatic Approximation  

Science Conference Proceedings (OSTI)

Second-order expansion of the aspect ratio gives rise to simple equations with a quasi-hydrostatic approximation that perform far better than the classical hydrostatic system in the simulation of moist convection in a mesoscale model. It also ...

Isidoro Orlanski

1981-03-01T23:59:59.000Z

38

BNL | Center for Functional Nanomaterials Hours of Operation  

NLE Websites -- All DOE Office Websites (Extended Search)

CFN Hours of Operation CFN Hours of Operation Normal working hours at the CFN are 8 a.m. to 6 p.m. Working Outside of Normal Hours CFN scientific and technical personnel, as well as external users, may need to work outside of normal operating hours, during which time support is limited and many colleagues may not be around. Therefore, working outside the 8 a.m. to 6 p.m. envelope on weekdays, or anytime on weekends and holidays, requires special precautions, especially if working in a laboratory. CFN users are expected to work at the CFN during normal working hours. Users with extensive experience working at the CFN may be granted permission by the appropriate facility leader and ES&H Coordinator to work after hours. Users first must complete the Request to Work After-Hours at

39

Results of the 1000 Hour Rotary Microfilter Endurance Test  

Stellite on Nitronic 60. 8 SRNL-L3100-2010-00229 Rotary Microfilter 1000 Hour Test Flux Data for 1000 Hour Test 0 1 2 3 4 5 6 0 100 200 300 400 500 ...

40

Heat pipe transient response approximation.  

SciTech Connect

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper.

Reid, R. S. (Robert Stowers)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Hydrogen Beyond the Classic Approximation  

E-Print Network (OSTI)

The classical nucleus approximation is the most frequently used approach for the resolution of problems in condensed matter physics.However, there are systems in nature where it is necessary to introduce the nuclear degrees of freedom to obtain a correct description of the properties.Examples of this, are the systems with containing hydrogen.In this work, we have studied the resolution of the quantum nuclear problem for the particular case of the water molecule.The Hartree approximation has been used, i.e. we have considered that the nuclei are distinguishable particles.In addition, we have proposed a model to solve the tunneling process, which involves the resolution of the nuclear problem for configurations of the system away from its equilibrium position

Scivetti, I

2003-01-01T23:59:59.000Z

42

Equivalence of Local Potential Approximations  

E-Print Network (OSTI)

In recent papers it has been noted that the local potential approximation of the Legendre and Wilson-Polchinski flow equations give, within numerical error, identical results for a range of exponents and Wilson-Fisher fixed points in three dimensions, providing a certain ``optimised'' cutoff is used for the Legendre flow equation. Here we point out that this is a consequence of an exact map between the two equations, which is nothing other than the exact reduction of the functional map that exists between the two exact renormalization groups. We note also that the optimised cutoff does not allow a derivative expansion beyond second order.

Tim R. Morris

2005-03-21T23:59:59.000Z

43

Hospital Triage in First Hours After Nuclear or Radiological...  

NLE Websites -- All DOE Office Websites (Extended Search)

Hospital Triage in the First 24 Hours after a Nuclear or Radiological Disaster Medical professionals with the Radiation Emergency Assistance CenterTraining Site (REACTS) at the...

44

Delayed Start or Cancellation of Business Hours | Argonne National...  

NLE Websites -- All DOE Office Websites (Extended Search)

Twitter Delayed Start or Cancellation of Business Hours Winter Road Closings Winter Weather FAQs Westgate Alternate Routes Reporting IllegalUnethical Activity Working Remotely...

45

Does EIA publish data on peak or hourly electricity ...  

U.S. Energy Information Administration (EIA)

Financial market analysis and financial ... load (or demand) data in our Electric Power Annual ... hourly load/demand profiles for some Independent ...

46

Report of 1,000 Hour Catalyst Longevity Evaluation  

DOE Green Energy (OSTI)

This report presents the results of a 1,000 hour, high-pressure, catalyst longevity test for the decomposition of concentrated sulfuric acid. The reaction is used for both the sulfur-iodine (S-I) cycle and hybrid sulfur cycle. By the time of the delivery date of April 17, 2009, for project milestone no. 2NIN07TC050114, the 1% Pt/TiO2 catalyst had been in the reaction environment for 658 hours. During the first 480 hours of testing, the catalyst activity provided stable, near-equilibrium yields of 46.8% SO2 and 22.8% O2. However, product yields declined at sample exposure times >480 hours. At 658 hours of operation, catalyst activity (based on oxygen yield) declined to 57% relative to the stable period of catalyst activity. Thus, as of April 17, this catalyst did not provide the desired stability level of <10% degradation per 1,000 hours. The experiment was terminated on April 27, after 792 hours, when a fitting failed and the catalyst was displaced from the reactor such that the sample could not be recovered. Oxygen conversion at the end of the experiment was 12.5% and declining, suggesting that at that point, catalyst activity had decreased to 54% of the initial level.

Daniel M. Ginosar

2009-06-01T23:59:59.000Z

47

Six- and three-hourly meteorological observations from 223 USSR stations  

SciTech Connect

This document describes a database containing 6- and 3-hourly meteorological observations from a 223-station network of the former Soviet Union. These data have been made available through cooperation between the two principal climate data centers of the United States and Russia: the National Climatic Data Center (NCDC), in Asheville, North Carolina, and the All-Russian Research Institute of Hydrometeorological Information -- World Data Centre (RIHMI-WDC) in Obninsk. Station records consist of 6- and 3-hourly observations of some 24 meteorological variables including temperature, weather type, precipitation amount, cloud amount and type, sea level pressure, relative humidity, and wind direction and speed. The 6-hourly observations extend from 1936 to 1965; the 3-hourly observations extend from 1966 through the mid-1980s (1983, 1984, 1985, or 1986; depending on the station). These data have undergone extensive quality assurance checks by RIHMI-WDC, NCDC, and the Carbon Dioxide Information Analysis Center (CDIAC). The database represents a wealth of meteorological information for a large and climatologically important portion of the earth`s land area, and should prove extremely useful for a wide variety of regional climate change studies. These data are available free of charge as a numeric data package (NDP) from CDIAC. The NDP consists of this document and 40 data files that are available via the Internet or on 8mm tape. The total size of the database is {approximately}2.6 gigabytes.

Razuvaev, V.N.; Apasova, E.B.; Martuganov, R.A. [All-Russian Research Inst. of Hydrometeorologicl Information, Obninsk (Russia). World Data Centre; Kaiser, D.P. [Oak Ridge National Lab., TN (United States)

1995-04-01T23:59:59.000Z

48

Development of an Hourly Optimization Tool for Renewable Energy Systems  

SciTech Connect

An hourly optimization tool is developed to select and size renewable energy (RE) systems to meet the energy needs for various federal facilities. The optimization is based on life cost analysis of various RE technologies including wind and PV systems. The developed hourly optimization tool is used to evaluate the cost-effectiveness of RE technologies using complex energy and demand charges such time-of-use (TOU) rates. The paper compares results obtained using hourly analysis instead of annual based calculations to optimize the sizing of RE systems for residential, commercial, and industrial facilities in three representative US climates.

Lee, C.; Walker, A.; Krarti, M.

2010-01-01T23:59:59.000Z

49

Particle motion in a Yang-Mills field Wong's equations and spin one-half analogues  

E-Print Network (OSTI)

A complete, straightforward and natural Lagrangian description is given for the classical non-relativistic dynamics of a particle with colour or internal symmetry degrees of freedom moving in a background Yang-Mills field. This provides a new simple Lagrangian formalism for Wong's equations for spinless particles, and presents also their generalisation, in gauge covariant form, for spin-\\frack particles, within a complete Lagrangian formalism.

Van Holten, J W

1995-01-01T23:59:59.000Z

50

Particle Motion in a Yang-Mills Field: Wong's Equations and Spin One-half Analogues  

E-Print Network (OSTI)

A complete, straightforward and natural Lagrangian description is given for the classical non-relativistic dynamics of a particle with colour or internal symmetry degrees of freedom moving in a background Yang-Mills field. This provides a new simple Lagrangian formalism for Wong's equations for spinless particles, and presents also their generalisation, in gauge covariant form, for spin-$\\frack$ particles, within a complete Lagrangian formalism.

N Linden A J Macfarlane; J W van Holten

1995-12-11T23:59:59.000Z

51

NCNR Quantum Impurities in the 2 D Spin One-Half ...  

Science Conference Proceedings (OSTI)

... The hope for insight into the physics of high temperature superconductors has generated enormous interest in the case of the two-dimensional (2 D ...

52

A Quality Assurance System for Canadian Hourly Pressure Data  

Science Conference Proceedings (OSTI)

In this study a comprehensive quality assurance (QA) system, which includes the hydrostatic check combined with a statistical homogeneity test, is designed and applied to hourly pressure records (for 1953–2002) from 761 Canadian stations, to ...

Hui Wan; Xiaolan L. Wang; Val R. Swail

2007-11-01T23:59:59.000Z

53

Complex Quality Assurance of Historical Hourly Surface Airways Meteorological Data  

Science Conference Proceedings (OSTI)

A new complex quality assurance (QA) procedure is developed for historical hourly surface airways meteorological data, recently digitized in a U.S. government–sponsored effort that extends the digital period of record back as early as the late ...

Daniel Y. Graybeal; Arthur T. DeGaetano; Keith L. Eggleston

2004-08-01T23:59:59.000Z

54

Team Surpasses 1 Million Hours Safety Milestone | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Team Surpasses 1 Million Hours Safety Milestone Team Surpasses 1 Million Hours Safety Milestone Team Surpasses 1 Million Hours Safety Milestone October 30, 2013 - 12:00pm Addthis The Separations Process Research Unit Demolition Project Safety Committee meets regularly with employees and supervisors to discuss safety issues and reinforce safe work habits. The Separations Process Research Unit Demolition Project Safety Committee meets regularly with employees and supervisors to discuss safety issues and reinforce safe work habits. NISKAYUNA, N.Y. - Vigilance and dedication to safety led the EM program's disposition project team at the Separations Process Research Unit (SPRU) to achieve a milestone of one million hours - over two-and-a-half-years - without injury or illness resulting in time away from work.

55

Team Surpasses 1 Million Hours Safety Milestone | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Team Surpasses 1 Million Hours Safety Milestone Team Surpasses 1 Million Hours Safety Milestone Team Surpasses 1 Million Hours Safety Milestone October 30, 2013 - 12:00pm Addthis The Separations Process Research Unit Demolition Project Safety Committee meets regularly with employees and supervisors to discuss safety issues and reinforce safe work habits. The Separations Process Research Unit Demolition Project Safety Committee meets regularly with employees and supervisors to discuss safety issues and reinforce safe work habits. NISKAYUNA, N.Y. - Vigilance and dedication to safety led the EM program's disposition project team at the Separations Process Research Unit (SPRU) to achieve a milestone of one million hours - over two-and-a-half-years - without injury or illness resulting in time away from work.

56

Global Solar Radiation Estimation from Relative Sunshine Hours in Italy  

Science Conference Proceedings (OSTI)

We examine the existing measurements of global solar radiation and sunshine duration for Italy, and evaluate the errors made in estimating global solar radiation from sunshine hours measurements. We find that the Ångstrom–Black linear relation in ...

A. Andretta; B. Bartoli; B. Coluzzi; V. Cuomo; M. Francesca; C. Serio

1982-10-01T23:59:59.000Z

57

Airport quotas and peak hour pricing : theory and practice  

E-Print Network (OSTI)

This report examines the leading theoretical studies not only of airport peak-hour pricing but also of the congestion costs associated with airport delays and presents a consistent formulation of both. The report also ...

Odoni, Amedeo R.

1976-01-01T23:59:59.000Z

58

An Hourly Assimilation–Forecast Cycle: The RUC  

Science Conference Proceedings (OSTI)

The Rapid Update Cycle (RUC), an operational regional analysis–forecast system among the suite of models at the National Centers for Environmental Prediction (NCEP), is distinctive in two primary aspects: its hourly assimilation cycle and its use ...

Stanley G. Benjamin; Dezsö Dévényi; Stephen S. Weygandt; Kevin J. Brundage; John M. Brown; Georg A. Grell; Dongsoo Kim; Barry E. Schwartz; Tatiana G. Smirnova; Tracy Lorraine Smith; Geoffrey S. Manikin

2004-02-01T23:59:59.000Z

59

Hourly Energy Emission Factors for Electricity Generation in...  

Open Energy Info (EERE)

Hourly Energy Emission Factors for Electricity Generation in the United States

Emissions from energy use in buildings are usually estimated on an annual...

60

Saturated Pseudoadiabats—A Noniterative Approximation  

Science Conference Proceedings (OSTI)

Two noniterative approximations are presented for saturated pseudoadiabats (also known as moist adiabats). One approximation determines which moist adiabat passes through a point of known pressure and temperature, such as through the lifting ...

Atoossa Bakhshaii; Roland Stull

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Rational Approximation for a Quasilinear Parabolic Equation  

E-Print Network (OSTI)

Approximation theorems, analogous to known results for linear elliptic equations, are obtained for solutions of the heat equation. Via the Cole-Hopf transformation, this gives rise to approximation theorems for a nonlinear parabolic equation, Burgers' equation.

P. M. Gauthier; N. Tarkhanov

2007-09-22T23:59:59.000Z

62

Enabling ?-approximate querying in sensor networks  

Science Conference Proceedings (OSTI)

Data approximation is a popular means to support energy-efficient query processing in sensor networks. Conventional data approximation methods require users to specify fixed error bounds a prior to address the trade-off between result accuracy ...

Liu Yu; Jianzhong Li; Hong Gao; Xiaolin Fang

2009-08-01T23:59:59.000Z

63

Approximations: Atomic Ref. Data Elect. Struct. Calculations  

Science Conference Proceedings (OSTI)

... where ? xc (?) is the exchange-correlation energy per particle for the uniform electron gas of density ?. This approximation ...

64

Form EIA-930 HOURLY AND DAILY BALANCING AUTHORITY OPERATIONS REPORT  

U.S. Energy Information Administration (EIA) Indexed Site

930 930 HOURLY AND DAILY BALANCING AUTHORITY OPERATIONS REPORT INSTRUCTIONS Due Date: mm/dd/yyyy Approved: OMB No. 1905-0129 Approval Expires: 10/31/2016 Burden: 0.19 hours Page 1 Draft for Discussion only PURPOSE Form EIA-930 requires Internet posting of hourly balancing authority operating data. The posted data are used to monitor the current status and trends of the electric power industry, and to support enhancement of electric system operations. REQUIRED RESPONDENTS For the contiguous United States: all entities that are listed in NERC's Compliance Registry as a balancing authority must post balancing authority operating information required by this survey. Other than the Midwest ISO (MISO), registered balancing authorities that are parties

65

Hourly Energy Emission Factors for Electricity Generation in the United  

Open Energy Info (EERE)

Hourly Energy Emission Factors for Electricity Generation in the United Hourly Energy Emission Factors for Electricity Generation in the United States Dataset Summary Description Emissions from energy use in buildings are usually estimated on an annual basis using annual average multipliers. Using annual numbers provides a reasonable estimation of emissions, but it provides no indication of the temporal nature of the emissions. Therefore, there is no way of understanding the impact on emissions from load shifting and peak shaving technologies such as thermal energy storage, on-site renewable energy, and demand control. This project utilized GridViewTM, an electric grid dispatch software package, to estimate hourly emission factors for all of the eGRID subregions in the continental United States. These factors took into account electricity imports and exports

66

INCITE Program Doles Out Hours on Supercomputers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

INCITE Program Doles Out Hours on Supercomputers INCITE Program Doles Out Hours on Supercomputers INCITE Program Doles Out Hours on Supercomputers November 5, 2012 - 1:30pm Addthis Mira, the 10-petaflop IBM Blue Gene/Q system at Argonne National Laboratory, is capable of carrying out 10 quadrillion calculations per second. Each year researchers apply to the INCITE program to get to use this machine's incredible computing power. | Photo courtesy of Argonne National Lab. Mira, the 10-petaflop IBM Blue Gene/Q system at Argonne National Laboratory, is capable of carrying out 10 quadrillion calculations per second. Each year researchers apply to the INCITE program to get to use this machine's incredible computing power. | Photo courtesy of Argonne National Lab. Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science

67

Optimizing hourly hydro operations at the Salt Lake City Area integrated projects  

DOE Green Energy (OSTI)

The Salt Lake City Area (SLCA) office of the Western Area Power Administration (Western) is responsible for marketing the capacity and energy generated by the Colorado Storage, Collbran, and Rio Grande hydropower projects. These federal resources are collectively called the Salt Lake City Area Integrated Projects (SLCA/IP). In recent years, stringent operational limitations have been placed on several of these hydropower plants including the Glen Canyon Dam, which accounts for approximately 80% of the SLCA/IP resources. Operational limitations on SLCA/IP hydropower plants continue to evolve as a result of decisions currently being made in the Glen Canyon Dam Environmental Impact Statement (EIS) and the Power Marketing EIS. To analyze a broad range of issues associated with many possible future operational restrictions, Argonne National Laboratory (ANL), with technical assistance from Western has developed the Hydro LP (Linear Program) Model. This model simulates hourly operations at SLCA/IP hydropower plants for weekly periods with the objective of maximizing Western`s net revenues. The model considers hydropower operations for the purpose of serving SLCA firm loads, loads for special projects, Inland Power Pool (IPP) spinning reserve requirements, and Western`s purchasing programs. The model estimates hourly SLCA/IP generation and spot market activities. For this paper, hourly SLCA/IP hydropower plant generation is simulated under three operational scenarios and three hydropower conditions. For each scenario an estimate of Western`s net revenue is computed.

Veselka, T.D.; Hamilton, S. [Argonne National Lab., IL (United States); McCoy, J. [Western Area Power Administration, Salt Lake City, UT (United States)

1995-06-01T23:59:59.000Z

68

Renewable Energies program (6 credit hour) Option A: 11  

E-Print Network (OSTI)

Renewable Energies program (6 credit hour) Option A: 11 Option B: The program is organized by t Spanish Institute and the Asso program on renewable energy will provide students with advanced knowledge. opportunities: option A- two renewable energies; option B include on-site visits to renewable energy generation

Simaan, Nabil

69

A Quality-Control Routine for Hourly Wind Observations  

Science Conference Proceedings (OSTI)

The quality of hourly wind speed and direction observations from 41 northeastern U.S. first-order weather stations is evaluated with regard to the recognition of individual observations that are either obviously in error or of suspect quality. An ...

Arthur T. DeGaetano

1997-04-01T23:59:59.000Z

70

An approximation trichotomy for Boolean #CSP  

E-Print Network (OSTI)

We give a trichotomy theorem for the complexity of approximately counting the number of satisfying assignments of a Boolean CSP instance. Such problems are parameterised by a constraint language specifying the relations that may be used in constraints. If every relation in the constraint language is affine then the number of satisfying assignments can be exactly counted in polynomial time. Otherwise, if every relation in the constraint language is in the co-clone IM_2 from Post's lattice, then the problem of counting satisfying assignments is complete with respect to approximation-preserving reductions in the complexity class #RH\\Pi_1. This means that the problem of approximately counting satisfying assignments of such a CSP instance is equivalent in complexity to several other known counting problems, including the problem of approximately counting the number of independent sets in a bipartite graph. For every other fixed constraint language, the problem is complete for #P with respect to approximation-prese...

Dyer, Martin; Jerrum, Mark

2007-01-01T23:59:59.000Z

71

Improved Error Bounds for the Adiabatic Approximation  

E-Print Network (OSTI)

Since the discovery of adiabatic quantum computing, a need has arisen for rigorously proven bounds for the error in the adiabatic approximation. We present in this paper, a rigorous and elementary derivation of upper and lower bounds on the error incurred from using the adiabatic approximation for quantum systems. Our bounds are often asymptotically tight in the limit of slow evolution for fixed Hamiltonians, and are used to provide sufficient conditions for the application of the adiabatic approximation. We show that our sufficiency criteria exclude the Marzlin--Sanders counterexample from the class of Hamiltonians that obey the adiabatic approximation. Finally, we demonstrate the existence of classes of Hamiltonians that resemble the Marzlin--Sanders counterexample Hamiltonian, but also obey the adiabatic approximation.

Cheung, Donny; Wiebe, Nathan

2011-01-01T23:59:59.000Z

72

Determination of approximate nonlinear self-adjointenss and approximate conservation law  

E-Print Network (OSTI)

Approximate nonlinear self-adjointness is an effective method to construct approximate conservation law of perturbed partial differential equations (PDEs). In this paper, we study the relations between approximate nonlinear self-adjointness of perturbed PDEs and nonlinear self-adjointness of the corresponding unperturbed PDEs, and consequently provide a simple approach to discriminate approximate nonlinear self-adjointness of perturbed PDEs. Moreover, a succinct approximate conservation law formula by virtue of the known conservation law of the unperturbed PDEs is given in an explicit form. As an application, we classify a class of perturbed wave equations to be approximate nonlinear self-adjointness and construct the general approximate conservation laws formulae. The specific examples demonstrate that approximate nonlinear self-adjointness can generate new approximate conservation laws.

Zhi-Yong Zhang

2013-01-19T23:59:59.000Z

73

Amp-hour counting control for PV hybrid power systems  

SciTech Connect

The performance of an amp-hour (Ah) counting battery charge control algorithm has been defined and tested using the Digital Solar Technologies MPR-9400 microprocessor based PV hybrid charge controller. This work included extensive field testing of the charge algorithm on flooded lead-antimony and valve regulated lead-acid (VRLA) batteries. The test results after one-year have demonstrated that PV charge utilization, battery charge control, and battery state of charge (SOC) has been significantly improved by providing maximum charge to the batteries while limiting battery overcharge to manufacturers specifications during variable solar resource and load periods.

Hund, T.D. [Sandia National Labs., Albuquerque, NM (United States); Thompson, B. [Biri Systems, Ithaca, NY (United States)

1997-06-01T23:59:59.000Z

74

Polymer state approximations of Schroedinger wave functions  

E-Print Network (OSTI)

It is shown how states of a quantum mechanical particle in the Schroedinger representation can be approximated by states in the so-called polymer representation. The result may shed some light on the semiclassical limit of loop quantum gravity.

Klaus Fredenhagen; Felix Reszewski

2006-06-21T23:59:59.000Z

75

Improved approximations for k-exchange systems  

Science Conference Proceedings (OSTI)

Submodular maximization and set systems play a major role in combinatorial optimization. It is long known that the greedy algorithm provides a 1/(k + 1)-approximation for maximizing a monotone submodular function over a k-system. For the ...

Moran Feldman; Joseph Naor; Roy Schwartz; Justin Ward

2011-09-01T23:59:59.000Z

76

N-Stream Approximations to Radiative Transfer  

Science Conference Proceedings (OSTI)

Schuster's two-stream approximation is first derived from Chandrasekhar's radiative transfer equation, and then generalized to an arbitrary number of streams. The resulting technique for solving the transfer equation that is similar to the ...

Charles Acquista; Frederick House; James Jafolla

1981-07-01T23:59:59.000Z

77

Linear source approximation in CASMO5  

Science Conference Proceedings (OSTI)

A Linear Source (LS) approximation has been implemented in the two-dimensional Method of Characteristics (MOC) transport solver in a prototype version of CASMO5. The LS approximation, which relies on the computation of trajectory-based spatial moments over source regions to obtain the linear source expansion coefficients, improves the solution accuracy relative to the 'flat' or constant source approximation. In addition, the LS formulation is capable of treating arbitrarily-shaped source regions and is compatible with standard Coarse-Mesh Finite Difference (CMFD) acceleration. Numerical tests presented in this paper for the C5G7 MOX benchmark show that, for comparable accuracy with respect to the reference solution, the LS approximation can reduce the run time by a factor of four and the memory requirements by a factor often relative to the FS scheme. (authors)

Ferrer, R.; Rhodes, J. [Studsvik Scandpower, Inc., 504 Shoup Ave., Idaho Falls, ID 83402 (United States); Smith, K. [Dept. of Nuclear Science and Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

2012-07-01T23:59:59.000Z

78

Blind multiuser detection based on kernel approximation  

Science Conference Proceedings (OSTI)

A kernel based multiuser detection (MUD) scheme in code-division multiple-access (CDMA) system is proposed. In this scheme, the support vector (SV) under support vector (SVM) framework is obtained through a kernel sparsity approximation, which regulates ...

Tao Yang; Bo Hu

2006-05-01T23:59:59.000Z

79

Casimir forces beyond the proximity approximation  

E-Print Network (OSTI)

The proximity force approximation (PFA) relates the interaction between closely spaced, smoothly curved objects to the force between parallel plates. Precision experiments on Casimir forces necessitate, and spur research ...

Bimonte, G.

80

Convergence Rates of Approximation by Translates  

E-Print Network (OSTI)

In this paper we consider the problem of approximating a function belonging to some funtion space Φ by a linear comination of n translates of a given function G. Ussing a lemma by Jones (1990) and Barron (1991) we show ...

Girosi, Federico

1992-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Small scale ethanol production: design manual. [10 to 15 gallons per hour  

DOE Green Energy (OSTI)

The purpose of the project was to design, fabricate, and evaluate a small scale continuous ethanol plant. The scope of the study was to satisfy four specific objectives. The first objective was to design a small scale continuous distillation unit capable of producing 10 to 15 gallons per hour of 170 to 190 proof ethanol. A second objective was to economically fabricate the distillation unit. A third objective was to thoroughly evaluate the unit with emphasis on production potential, operation considerations, and energy balance. The fourth objective was to work with the Farm Bureau in identifying an organization that would place the unit in a production environment. The results of the study indicate that the distillation unit is capable of producing and average of 9 to 14 gallons per hour (based on alcohol percent in beer) of 174 proof ethanol. The energy ratio for distillation is a positive 3:1. Once the unit has reached steady state very little operator attention is required with the exception of periodically refluxing. Material cost of the plate column is approximately $5000. The unit could be built by an individual provided he is trained in welding and has the necessary shop equipment. 39 figures, 12 tables.

Adcock, L.E. II; Eley, M.H.; Schroer, B.J.

1981-09-01T23:59:59.000Z

82

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Kenya from NREL Kenya from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a location, if enough years of data are present. The TMY consists of months selected from individual years and concatenated to form a complete year.. Because of the selection criteria, these TMYs are not appropriate for simulations of wind energy conversion systems. A TMY provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. Rather, it represents conditions judged to be typical over a long period of time, such as 30 years.

83

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

China from NREL China from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a location, if enough years of data are present. The TMY consists of months selected from individual years and concatenated to form a complete year. Because of the selection criteria, these TMYs are not appropriate for simulations of wind energy conversion systems. A TMY provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. Rather, it represents conditions judged to be typical over a long period of time, such as 30 years.

84

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Bangladesh stations from NREL Bangladesh stations from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a location, if enough years of data are present. The TMY consists of months selected from individual years and concatenated to form a complete year.. Because of the selection criteria, these TMYs are not appropriate for simulations of wind energy conversion systems. A TMY provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. Rather, it represents conditions judged to be typical over a long period of time, such as 30 years.

85

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Cuba from NREL Cuba from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a location, if enough years of data are present. The TMY consists of months selected from individual years and concatenated to form a complete year.. Because of the selection criteria, these TMYs are not appropriate for simulations of wind energy conversion systems. A TMY provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. Rather, it represents conditions judged to be typical over a long period of time, such as 30 years.

86

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Nepal from NREL Nepal from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a location, if enough years of data are present. The TMY consists of months selected from individual years and concatenated to form a complete year.. Because of the selection criteria, these TMYs are not appropriate for simulations of wind energy conversion systems. A TMY provides a standard for hourly data for solar radiation and other meteorological elements that permit performance comparisons of system types and configurations for one or more locations. A TMY is not necessarily a good indicator of conditions over the next year, or even the next 5 years. Rather, it represents conditions judged to be typical over a long period of time, such as 30 years.

87

Folding Proteins at 500 ns/hour with Work Queue  

E-Print Network (OSTI)

Abstract—Molecular modeling is a field that traditionally has large computational costs. Until recently, most simulation techniques relied on long trajectories, which inherently have poor scalability. A new class of methods is proposed that requires only a large number of short calculations, and for which minimal communication between computer nodes is required. We considered one of the more accurate variants called Accelerated Weighted Ensemble Dynamics (AWE) and for which distributed computing can be made efficient. We implemented AWE using the Work Queue framework for task management and applied it to an all atom protein model (Fip35 WW domain). We can run with excellent scalability by simultaneously utilizing heterogeneous resources from multiple computing platforms such as clouds (Amazon EC2, Microsoft Azure), dedicated clusters, grids, on multiple architectures (CPU/GPU, 32/64bit), and in a dynamic environment in which processes are regularly added or removed from the pool. This has allowed us to achieve an aggregate sampling rate of over 500 ns/hour. As a comparison, a single process typically achieves 0.1 ns/hour. I.

Badi Abdul-wahid; Li Yu; Dinesh Rajan

2012-01-01T23:59:59.000Z

88

An approximation trichotomy for Boolean #CSP  

E-Print Network (OSTI)

We give a trichotomy theorem for the complexity of approximately counting the number of satisfying assignments of a Boolean CSP instance. Such problems are parameterised by a constraint language specifying the relations that may be used in constraints. If every relation in the constraint language is affine then the number of satisfying assignments can be exactly counted in polynomial time. Otherwise, if every relation in the constraint language is in the co-clone IM2 from Post’s lattice, then the problem of counting satisfying assignments is complete with respect to approximation-preserving reductions in the complexity class #RH?1. This means that the problem of approximately counting satisfying assignments of such a CSP instance is equivalent in complexity to several other known counting problems, including the problem of approximately counting the number of independent sets in a bipartite graph. For every other fixed constraint language, the problem is complete for #P with respect to approximation-preserving reductions, meaning that there is no fully polynomial randomised approximation scheme for counting satisfying assignments unless NP=RP. 1

Martin Dyer; Leslie Ann Goldberg; Mark Jerrum

2007-01-01T23:59:59.000Z

89

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Ghana from NREL Ghana from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a

90

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Sri Lanka from NREL Sri Lanka from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a

91

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

El Salvador sites from SUNY El Salvador sites from SUNY Dataset Summary Description (Abstract): Zip file contains year-site specific files including time series of global, direct and diffuse irradiance (Purpose): The time series are useful for performing site specific simulation of customized solar energy systems (Supplemental Information): Each file's name identifies year and location, by listing Country_City_latitude-longitude_year, e.g., EL_SALVADOR_San_Salvador_13.75-89.15_98.out is for the city of San Salvador, in El Salvador, latitude 13.75 degrees, longitude -89.15 degrees, year 1998. The content of each file includes A one line header, listing latitude, longitude and ground elevation in meters,Hourly records including, year, month, day, time (GMT), global irradiance, direct irradiance and

92

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Ethiopia from NREL Ethiopia from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a

93

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Honduras from SUNY Honduras from SUNY Dataset Summary Description (Abstract): Zip file contains year-site specific files including time series of global, direct and diffuse irradiance (Purpose): The time series are useful for performing site specific simulation of customized solar energy systems (Supplemental Information): Each file's name identifies year and location, by listing Country_City_latitude-longitude_year, e.g., EL_SALVADOR_San_Salvador_13.75-89.15_98.out is for the city of San Salvador, in El Salvador, latitude 13.75 degrees, longitude -89.15 degrees, year 1998. The content of each file includes A one line header, listing latitude, longitude and ground elevation in meters,Hourly records including, year, month, day, time (GMT), global irradiance, direct irradiance and

94

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Brazil from NREL Brazil from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a

95

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Nicaragua from SUNY Nicaragua from SUNY Dataset Summary Description (Abstract): Zip file contains year-site specific files including time series of global, direct and diffuse irradiance (Purpose): The time series are useful for performing site specific simulation of customized solar energy systems (Supplemental Information): Each file's name identifies year and location, by listing Country_City_latitude-longitude_year, e.g., EL_SALVADOR_San_Salvador_13.75-89.15_98.out is for the city of San Salvador, in El Salvador, latitude 13.75 degrees, longitude -89.15 degrees, year 1998. The content of each file includes A one line header, listing latitude, longitude and ground elevation in meters,Hourly records including, year, month, day, time (GMT), global irradiance, direct irradiance and

96

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Central America from NREL Central America from NREL Dataset Summary Description (Abstract): Each data file is a set of hourly values of solar radiation and meteorological elements for a 1-year period. Solar radiation is modeled using the NREL METSTAT model, with surface observed cloud cover being the principal model input. Each container file contains up to 30 yearly files for one station, plus the Typical Meteorological Year (TMY) file for the selected station, plus documentation files and a TMY data reader file for use with Microsoft Excel. (Purpose): Simulations (Supplemental Information): The intended use of these data files is for computer simulations of solar energy conversion systems and building systems. The yearly data may be suitable for designing systems and their components to meet the worst-case conditions occurring at a

97

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Guatemala from SUNY Guatemala from SUNY Dataset Summary Description (Abstract): Zip file contains year-site specific files including time series of global, direct and diffuse irradiance (Purpose): The time series are useful for performing site specific simulation of customized solar energy systems (Supplemental Information): Each file's name identifies year and location, by listing Country_City_latitude-longitude_year, e.g., EL_SALVADOR_San_Salvador_13.75-89.15_98.out is for the city of San Salvador, in El Salvador, latitude 13.75 degrees, longitude -89.15 degrees, year 1998. The content of each file includes A one line header, listing latitude, longitude and ground elevation in meters,Hourly records including, year, month, day, time (GMT), global irradiance, direct irradiance and

98

Solar: hourly solar (direct normal (DNI), global horizontal (GHI), and  

Open Energy Info (EERE)

Cuba sites from SUNY Cuba sites from SUNY Dataset Summary Description (Abstract): Zip file contains year-site specific files including time series of global, direct and diffuse irradiance (Purpose): The time series are useful for performing site specific simulation of customized solar energy systems (Supplemental Information): Each file's name identifies year and location, by listing Country_City_latitude-longitude_year, e.g., EL_SALVADOR_San_Salvador_13.75-89.15_98.out is for the city of San Salvador, in El Salvador, latitude 13.75 degrees, longitude -89.15 degrees, year 1998. The content of each file includes A one line header, listing latitude, longitude and ground elevation in meters,Hourly records including, year, month, day, time (GMT), global irradiance, direct irradiance and

99

On the Accuracy of the MINC approximation  

DOE Green Energy (OSTI)

The method of ''multiple interacting continua'' is based on the assumption that changes in thermodynamic conditions of rock matrix blocks are primarily controlled by the distance from the nearest fracture. The accuracy of this assumption was evaluated for regularly shaped (cubic and rectangular) rock blocks with uniform initial conditions, which are subjected to a step change in boundary conditions on the surface. Our results show that pressures (or temperatures) predicted from the MINC approximation may deviate from the exact solutions by as much as 10 to 15% at certain points within the blocks. However, when fluid (or heat) flow rates are integrated over the entire block surface, MINC-approximation and exact solution agree to better than 1%. This indicates that the MINC approximation can accurately represent transient inter-porosity flow in fractured porous media, provided that matrix blocks are indeed subjected to nearly uniform boundary conditions at all times.

Lai, C.H.; Pruess, K.; Bodvarsson, G.S.

1986-02-01T23:59:59.000Z

100

The Exact Renormalisation Group and Approximate Solutions  

E-Print Network (OSTI)

We investigate the structure of Polchinski's formulation of the flow equations for the continuum Wilson effective action. Reinterpretations in terms of I.R. cutoff greens functions are given. A promising non-perturbative approximation scheme is derived by carefully taking the sharp cutoff limit and expanding in `irrelevancy' of operators. We illustrate with two simple models of four dimensional $\\lambda \\varphi^4$ theory: the cactus approximation, and a model incorporating the first irrelevant correction to the renormalized coupling. The qualitative and quantitative behaviour give confidence in a fuller use of this method for obtaining accurate results.

Tim R. Morris

1993-08-12T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Symbolic Test Selection Based on Approximate Analysis  

E-Print Network (OSTI)

Symbolic Test Selection Based on Approximate Analysis Bertrand Jeannet, Thierry J´eron, Vlad Rusu}@irisa.fr Abstract. This paper addresses the problem of generating symbolic test cases for testing the conformance. The challenge we consider is the selection of test cases according to a test purpose, which is here a set

Paris-Sud XI, Université de

102

Approximations to the Distributed Activation Energy Model  

E-Print Network (OSTI)

Approximations to the Distributed Activation Energy Model for Pyrolysis C.P. Please, 1 M.J. Mc, then resubmitted after minor revisions in September 2002. Abstract The Distributed Activation Energy Model (DAEM effective method for estimating kinetic parameters and the distribution of activation energies. Comparison

McGuinness, Mark

103

Nonlinear piecewise polynomial approximation: Theory and Algorithms  

E-Print Network (OSTI)

algorithms for compression and quick rendering of Digital Terrain Elevation Data (DTED) maps and implement by these and further theoretical results, we develop eÃ?cient practical algorithms for compression and quick rendering linear approximation 23 2.3. Slim B-spaces 32 2.4. Skinny B-spaces 42 2.5. Fat B-spaces: The link

Karaivanov, Borislav

104

Nonlinear piecewise polynomial approximation: Theory and Algorithms  

E-Print Network (OSTI)

algorithms for compression and quick rendering of Digital Terrain Elevation Data (DTED) maps and implement results, we develop efficient practical algorithms for compression and quick rendering of Digital Terrain approximation 23 2.3. Slim B-spaces 32 2.4. Skinny B-spaces 42 2.5. Fat B-spaces: The link to Besov spaces 46 2

Karaivanov, Borislav

105

Real-time creased approximate subdivision surfaces  

Science Conference Proceedings (OSTI)

We present an extension of recently developed Loop and Schaefer's approximation of Catmull-Clark surfaces (ACC) for surfaces with creases and corners which are essential for most applications. We discuss the integration of ACC into Valve's Source game ... Keywords: GPU tessellation, geometric modeling, hardware rendering, subdivision surfaces, video games

Denis Kovacs; Jason Mitchell; Shanon Drone; Denis Zorin

2009-02-01T23:59:59.000Z

106

Complete Orders, Categories and Lattices of Approximations  

Science Conference Proceedings (OSTI)

The present article deals with the problem whether and how the bilattice orderings of knowledge ⩽$_k$ and truth ⩽$_t$ might enrich the theory of rough sets. Passing to the chief idea of the paper, we develop a bilattice-theoretic generalisation ... Keywords: *-autonomous category, Chu construction, Nelson lattice, approximation, bilattice, complete partial order, rough set

Marcin Wolski

2006-09-01T23:59:59.000Z

107

UNIFORM SEMICLASSICAL APPROXIMATION IN QUANTUM STATISTICAL MECHANICS.  

SciTech Connect

We present a simple method to deal with caustics in the semiclassical approximation to the partition function of a one-dimensional quantum system. The procedure, which makes use of complex trajectories, is applied to the quartic double-well potential.

De Carvalho, C.A.A.; Cavalcanit, R.M.; Fraga, E.S.; Joras, S.E.

2000-10-23T23:59:59.000Z

108

Testing approximations beyond the proton-neutron quasiparticle random phase approximation  

Science Conference Proceedings (OSTI)

In this work we analyze the validity of recently proposed extensions of the Quasiparticle Random Phase Approximation (QRPA). Particularly, we focus our attention on the Fully Renormalized QRPA (FRQRPA). We found that the results of this approximation do not differ from the results of the QRPA. This finding is supported by a detailed comparison between both formalisms, their assumptions and approximations, in the context of realistic calculations.

Civitarese, O.; Mariano, A. [Department of Physics. University of La Plata, C. C. 67 1900 La Plata (Argentina); Hirsch, J. G. [Instituto de Ciencias Nucleares, UNAM, A. P. 70-543, 04510 Mexico City, D. F. (Mexico); Reboiro, M. [Department of Physics. University of La Plata, C. C. 67 1900 La Plata (Argentina); Faculty of Engineering, University of Lomas de Zamora, Km 2 (1836) Lavallol (Argentina)

2007-08-15T23:59:59.000Z

109

Approximating stochastic volatility by recombinant trees  

E-Print Network (OSTI)

A general method to construct recombinant tree approximations for stochastic volatility models is developed and applied to the Heston model for stock price dynamics. In this application, the resulting approximation is a four tuple Markov process. The ?first two components are related to the stock and volatility processes and take values in a two dimensional Binomial tree. The other two components of the Markov process are the increments of random walks with simple values in {-1; +1}. The resulting effi?cient option pricing equations are numerically implemented for general American and European options including the standard put and calls, barrier, lookback and Asian type pay-o?ffs. The weak and extended weak convergence are also proved.

Akyildirim, Erdinc; Soner, H Mete

2012-01-01T23:59:59.000Z

110

Approximate gauge symmetry of composite vector bosons  

SciTech Connect

It can be shown in a solvable field theory model that the couplings of the composite vector bosons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in a more intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.

Suzuki, Mahiko [Lawrence Berkeley National Laboratory and Department of Physics, University of California, Berkeley, California 94720 (United States)

2010-08-15T23:59:59.000Z

111

Approximate gauge symemtry of composite vector bosons  

SciTech Connect

It can be shown in a solvable field theory model that the couplings of the composite vector mesons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in more an intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.

Suzuki, Mahiko

2010-06-01T23:59:59.000Z

112

Dictionary Approximation For Matching Pursuit Video Coding  

E-Print Network (OSTI)

Previously, we demonstrated an efficient video codec based on overcomplete signal decomposition using matching pursuits. Dictionary design is an important issue for this system, and others have shown alternate dictionaries which lead to either coding efficiency improvements or reduced encoder complexity. In this work, we introduce for the first time a design methodology which incorporates both coding efficiency and complexity in a systematic way. The key to our new method is an algorithm which takes an arbitrary 2-D dictionary and generates approximations of the dictionary which have fast 2-stage implementations. By varying the quality of the approximation, we can explore a systematic tradeoff between the coding efficiency and complexity of the matching pursuit video encoder. As a practical result, we show cases where complexity is reduced by a factor of 500 to 1000 in exchange for small coding efficiency losses of around 0.1 dB PSNR. 1. INTRODUCTION Most video codecs in use today ar...

Ralph Neff; Avideh Zakhor

2000-01-01T23:59:59.000Z

113

Shear viscosity in the postquasistatic approximation  

Science Conference Proceedings (OSTI)

We apply the postquasistatic approximation, an iterative method for the evolution of self-gravitating spheres of matter, to study the evolution of anisotropic nonadiabatic radiating and dissipative distributions in general relativity. Dissipation is described by viscosity and free-streaming radiation, assuming an equation of state to model anisotropy induced by the shear viscosity. We match the interior solution, in noncomoving coordinates, with the Vaidya exterior solution. Two simple models are presented, based on the Schwarzschild and Tolman VI solutions, in the nonadiabatic and adiabatic limit. In both cases, the eventual collapse or expansion of the distribution is mainly controlled by the anisotropy induced by the viscosity.

Peralta, C.; Rosales, L.; Rodriguez-Mueller, B.; Barreto, W. [Deutscher Wetterdienst, Frankfurter Str. 135, 63067 Offenbach (Germany); Laboratorio de Fisica Computacional, Universidad Experimental Politecnica 'Antonio Jose de Sucre', Puerto Ordaz (Venezuela, Bolivarian Republic of); Computational Science Research Center, College of Sciences, San Diego State University, San Diego, California (United States); Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

2010-05-15T23:59:59.000Z

114

Estimating Hourly All-Sky Solar Irradiation Components from Meteorological Data  

Science Conference Proceedings (OSTI)

A new method to calculate hourly direct beam and diffuse irradiation on a horizontal surface using 3-h standard meteorological data is described. Comparisons of computed and observed irradiations are made with hourly data obtained in Carpentras ...

F. Kermel

1988-02-01T23:59:59.000Z

115

NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate...  

NLE Websites -- All DOE Office Websites (Extended Search)

NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate Change Models NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate Change Models September 11, 2008...

116

Seasonal Variations in the Diurnal Characteristics of Heavy Hourly precipitation across the United States  

Science Conference Proceedings (OSTI)

Hourly precipitation data from 1967 to 1983 for the coterminous, United States were harmonically analyzed in order to document the diurnal variability of several categories of heavy hourly precipitation during winter, spring, summer, and autumn. ...

Julie A. Winkler; Brent R. Skeeter; Paul D. Yamamoto

1988-08-01T23:59:59.000Z

117

Analytic approximate radiation effects due to Bremsstrahlung  

SciTech Connect

The purpose of this note is to provide analytic approximate expressions that can provide quick estimates of the various effects of the Bremsstrahlung radiation produced relatively low energy electrons, such as the dumping of the beam into the beam stop at the ERL or field emission in superconducting cavities. The purpose of this work is not to replace a dependable calculation or, better yet, a measurement under real conditions, but to provide a quick but approximate estimate for guidance purposes only. These effects include dose to personnel, ozone generation in the air volume exposed to the radiation, hydrogen generation in the beam dump water cooling system and radiation damage to near-by magnets. These expressions can be used for other purposes, but one should note that the electron beam energy range is limited. In these calculations the good range is from about 0.5 MeV to 10 MeV. To help in the application of this note, calculations are presented as a worked out example for the beam dump of the R&D Energy Recovery Linac.

Ben-Zvi I.

2012-02-01T23:59:59.000Z

118

Semiclassical approximation to supersymmetric quantum gravity  

SciTech Connect

We develop a semiclassical approximation scheme for the constraint equations of supersymmetric canonical quantum gravity. This is achieved by a Born-Oppenheimer type of expansion, in analogy to the case of the usual Wheeler-DeWitt equation. The formalism is only consistent if the states at each order depend on the gravitino field. We recover at consecutive orders the Hamilton-Jacobi equation, the functional Schroedinger equation, and quantum gravitational correction terms to this Schroedinger equation. In particular, the following consequences are found: (i) the Hamilton-Jacobi equation and therefore the background spacetime must involve the gravitino, (ii) a (many-fingered) local time parameter has to be present on super Riem {sigma} (the space of all possible tetrad and gravitino fields) (iii) quantum supersymmetric gravitational corrections affect the evolution of the very early Universe. The physical meaning of these equations and results, in particular, the similarities to and differences from the pure bosonic case, are discussed.

Kiefer, Claus; Lueck, Tobias; Moniz, Paulo [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany); Astronomy Unit, School of Mathematical Sciences, Queen Mary College, University of London, Mile End Road, London E1 4NS (United Kingdom)

2005-08-15T23:59:59.000Z

119

Heat flow in the postquasistatic approximation  

Science Conference Proceedings (OSTI)

We apply the postquasistatic approximation to study the evolution of spherically symmetric fluid distributions undergoing dissipation in the form of radial heat flow. For a model that corresponds to an incompressible fluid departing from the static equilibrium, it is not possible to go far from the initial state after the emission of a small amount of energy. Initially collapsing distributions of matter are not permitted. Emission of energy can be considered as a mechanism to avoid the collapse. If the distribution collapses initially and emits one hundredth of the initial mass only the outermost layers evolve. For a model that corresponds to a highly compressed Fermi gas, only the outermost shell can evolve with a shorter hydrodynamic time scale.

Rodriguez-Mueller, B. [Computational Science Research Center, College of Sciences, San Diego State University, San Diego, California (United States); Peralta, C. [Deutscher Wetterdienst, Frankfurter Strasse 135, 63067 Offenbach (Germany); School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Rosales, L. [Laboratorio de Fisica Computacional, Universidad Experimental Politecnica, 'Antonio Jose de Sucre', Puerto Ordaz (Venezuela, Bolivarian Republic of)

2010-08-15T23:59:59.000Z

120

Generic sequential sampling for metamodel approximations  

SciTech Connect

Metamodels approximate complex multivariate data sets from simulations and experiments. These data sets often are not based on an explicitly defined function. The resulting metamodel represents a complex system's behavior for subsequent analysis or optimization. Often an exhaustive data search to obtain the data for the metalnodel is impossible, so an intelligent sampling strategy is necessary. While inultiple approaches have been advocated, the majority of these approaches were developed in support of a particular class of metamodel, known as a Kriging. A more generic, cotninonsense approach to this problem allows sequential sampling techniques to be applied to other types of metamodeis. This research compares recent search techniques for Kriging inetamodels with a generic, inulti-criteria approach combined with a new type of B-spline metamodel. This B-spline metamodel is competitive with prior results obtained with a Kriging metamodel. Furthermore, the results of this research highlight several important features necessary for these techniques to be extended to more complex domains.

Turner, C. J. (Cameron J.); Campbell, M. I. (Matthew I.)

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Question of the Week: How Are You Observing Earth Hour? | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Are You Observing Earth Hour? Are You Observing Earth Hour? Question of the Week: How Are You Observing Earth Hour? March 26, 2009 - 12:16pm Addthis This Saturday, March 28th, people around the world will observe Earth Hour at 8:30 p.m. local time-whatever the local time zone happens to be-by switching off their lights for one hour. While many people are taking part by simply shutting off their lights and lighting some candles, some communities are hosting gatherings or events around Earth Hour. How are you observing Earth Hour? Each Thursday, you have the chance to share your thoughts on a topic related to energy efficiency or renewable energy for consumers. Please e-mail your responses to the Energy Saver team at consumer.webmaster@nrel.gov. Addthis Related Articles Question of the Week: How Will You Save Energy this Spring?

122

Comonotonic approximations for optimal portfolio selection problems  

E-Print Network (OSTI)

We investigate multiperiod portfolio selection problems in a Black & Scholes type market where a basket of 1 riskfree and m risky securities are traded continuously. We look for the optimal allocation of wealth within the class of ’constant mix ’ portfolios. First, we consider the portfolio selection problem of a decision maker who invests money at predetermined points in time in order to obtain a target capital at the end of the time period under consideration. A second problem concerns a decision maker who invests some amount of money (the initial wealth or provision) in order to be able to fullfil a series of future consumptions or payment obligations. Several optimality criteria and their interpretation within Yaari’s dual theory of choice under risk are presented. For both selection problems, we propose accurate approximations based on the concept of comonotonicity, as studied in Dhaene, Denuit, Goovaerts, Kaas & Vyncke (2002 a,b). Our analytical approach avoids simulation, and hence reduces the computing effort drastically. 1

J. Dhaene; S. Vanduffel; M. J. Goovaerts; R. Kaas; D. Vyncke

2005-01-01T23:59:59.000Z

123

Earth Hour 2009: March 28, 8:30-9:30 PM Local Time | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Earth Hour 2009: March 28, 8:30-9:30 PM Local Time Earth Hour 2009: March 28, 8:30-9:30 PM Local Time Earth Hour 2009: March 28, 8:30-9:30 PM Local Time March 27, 2009 - 6:00am Addthis John Lippert The city of Greenbelt, Maryland, where I live, is living up to its "green" name by participating in Earth Hour. This global event asks everyone to "go dark" for an hour to make a powerful statement of concern about climate change. The city will be turning off all non-essential lights in municipal buildings. Residents are requested to turn off their lights (and other energy-consuming appliances). The Greenbelt Advisory Committee on Environmental Sustainability, which advises the mayor and city council and which I chair, will be sponsoring a flashlight walk around Old Greenbelt during Earth Hour. My wife and I will

124

Earth Hour 2009: March 28, 8:30-9:30 PM Local Time | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Earth Hour 2009: March 28, 8:30-9:30 PM Local Time Earth Hour 2009: March 28, 8:30-9:30 PM Local Time Earth Hour 2009: March 28, 8:30-9:30 PM Local Time March 27, 2009 - 6:00am Addthis John Lippert The city of Greenbelt, Maryland, where I live, is living up to its "green" name by participating in Earth Hour. This global event asks everyone to "go dark" for an hour to make a powerful statement of concern about climate change. The city will be turning off all non-essential lights in municipal buildings. Residents are requested to turn off their lights (and other energy-consuming appliances). The Greenbelt Advisory Committee on Environmental Sustainability, which advises the mayor and city council and which I chair, will be sponsoring a flashlight walk around Old Greenbelt during Earth Hour. My wife and I will

125

Customer Strategies for Responding to Day-Ahead Market Hourly Electricity Pricing  

E-Print Network (OSTI)

facilities that receive electricity service from Niagaraperiods is your facility’s electricity use highest? ( CHECKthe next day’s hourly electricity prices? ( CHECK ONLY ONE )

2005-01-01T23:59:59.000Z

126

Customer Strategies for Responding to Day-Ahead Market Hourly Electricity Pricing  

E-Print Network (OSTI)

next day’s hourly electricity prices? ( CHECK ONLY ONE ) 1.to Real Time Electricity Prices, Unpublished Manuscript atahead Wholesale Market Electricity Prices: Case Study of RTP

2005-01-01T23:59:59.000Z

127

Analysis of Sub-Hourly Ramping Impacts of Wind Energy and Balancing Area Size: Preprint  

DOE Green Energy (OSTI)

In this paper, we analyze sub-hourly ramping requirements and the benefit of combining Balancing Authority operations with significant wind penetrations.

Milligan, M.; Kirby, B.

2008-06-01T23:59:59.000Z

128

Customer Strategies for Responding to Day-Ahead Market Hourly Electricity Pricing  

E-Print Network (OSTI)

nature of electric service and usage, defining the hoursElectric. 12 The resulting evaluation report estimated elasticities and found measurable reductions in energy usage

2005-01-01T23:59:59.000Z

129

Intra-hour Direct Normal Irradiance solar forecasting using genetic programming  

E-Print Network (OSTI)

UNIVERSITY OF CALIFORNIA, SAN DIEGO Intra-hour Direct NormalChair University of California, San Diego iii TABLE OFRPS,” Technical report, California Independent System

Queener, Benjamin Daniel

2012-01-01T23:59:59.000Z

130

Quantification of Variability and Uncertainty in Hourly NOx Emissions from Coal-Fired Power Plants  

E-Print Network (OSTI)

1 Quantification of Variability and Uncertainty in Hourly NOx Emissions from Coal-Fired Power to quantify variability and uncertainty for NOx emissions from coal-fired power plants. Data for hourly NOx Uncertainty, Variability, Emission Factors, Coal-Fired Power Plants, NOx emissions, Regression Models

Frey, H. Christopher

131

Multi-hour network planning based on domination between sets of traffic matrices  

Science Conference Proceedings (OSTI)

In multi-hour network design, periodic traffic variations along time are considered in the dimensioning process. Then, the non coincidence of traffic peaks along the day or the week can be exploited. This paper investigates the application of the traffic ... Keywords: Multi-hour traffic, Network planning, Traffic domination

P. Pavon-Marino; B. Garcia-Manrubia; R. Aparicio-Pardo

2011-02-01T23:59:59.000Z

132

Optimal Multi-scale Capacity Planning under Hourly Varying Electricity Prices  

E-Print Network (OSTI)

1 Optimal Multi-scale Capacity Planning under Hourly Varying Electricity Prices Sumit Mitra Ignacio;2 Motivation of this work · Deregulation of the electricity markets caused electricity prices to be highly? (retrofit) · Challenge: Multi-scale nature of the problem! Hourly varying electricity prices vs. 10-15 years

Grossmann, Ignacio E.

133

Cloudy Sky Version of Bird's Broadband Hourly Clear Sky Model (Presentation)  

DOE Green Energy (OSTI)

Presentation on Bird's Broadband Hourly Clear Sky Model given by NREL's Daryl Myers at SOLAR 2006. The objective of this report is to produce ''all sky'' modeled hourly solar radiation. This is based on observed cloud cover data using a SIMPLE model.

Myers, D.

2006-08-01T23:59:59.000Z

134

Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor Docket No. EO-05-01: Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor, March 2002 to November 2004, showing the model overprediction Mirant: Ambient 24 Hour SO2 Values: Model vs Monitor More Documents & Publications Comments on Department of Energy's Emergency Order To Resume Limited Operation at Mirant's Potomac River Generating Station and Proposed Mirant Compliance Plan Answer of Potomac Electric Power Company and PJM lnterconnection, L.L.C. to the October 6, 2005 motion filed by the Virginia Department of Environmental Quality Special Environmental Analysis For Actions Taken under U.S. Department of Energy Emergency Orders Regarding Operation of the Potomac River Generating

135

Derivation of 24-Hour Average SO2, Background for the Update 1 Report |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Derivation of 24-Hour Average SO2, Background for the Update 1 Derivation of 24-Hour Average SO2, Background for the Update 1 Report Derivation of 24-Hour Average SO2, Background for the Update 1 Report Docket No. EO-05-01. As supporting documentation for "Update 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant: Modeling Unit 1 Emissions in a Cycling Mode" this memo documents the fact that the observed 24-hour SO2 background concentrations during periods when meteorological conditions produce the highest impacts from Unit 1. Derivation of 24-Hour Average SO2, Background for the Update 1 Report More Documents & Publications Review of the ENSR Report Titled "Update 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant"

136

A Class of Semi-Lagrangian Approximations for Fluids  

Science Conference Proceedings (OSTI)

This paper discusses a class of finite-difference approximations to the evolution equations of fluid dynamics. These approximations derive from elementary properties of differential forms. Values of a fluid variable ? at any two points of a space-...

Piotr K. Smolarkiewicz; Janusz A. Pudykiewicz

1992-11-01T23:59:59.000Z

137

Four-Stream Isosector Approximation for Solar Radiative Transfer  

Science Conference Proceedings (OSTI)

For radiative transfer in a thin atmosphere, an analytical four-stream isosector approximation for solar radiative transfer is presented. This approximation method is based on the assumption of four spherical sectors of isotropic intensities. ...

J. Li; J. S. Dobbie

1998-02-01T23:59:59.000Z

138

Weak Pressure Gradient Approximation and Its Analytical Solutions  

Science Conference Proceedings (OSTI)

A weak pressure gradient (WPG) approximation is introduced for parameterizing supradomain-scale (SDS) dynamics, and this method is compared to the relaxed form of the weak temperature gradient (WTG) approximation in the context of 3D, linearized, ...

David M. Romps

2012-09-01T23:59:59.000Z

139

Dynamic Enthalpy, Conservative Temperature, and the Seawater Boussinesq Approximation  

Science Conference Proceedings (OSTI)

A new seawater Boussinesq system is introduced, and it is shown that this approximation to the equations of motion of a compressible binary solution has an energy conservation law that is a consistent approximation to the Bernoulli equation of ...

William R. Young

2010-02-01T23:59:59.000Z

140

Table A3. Approximate Heat Content of Petroleum Consumption and ...  

U.S. Energy Information Administration (EIA)

Table A3. Approximate Heat Content of Petroleum Consumption and Biofuels Production, 1949-2011 (Million Btu per Barrel)

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Weighted trapezoidal approximation-preserving cores of a fuzzy number  

Science Conference Proceedings (OSTI)

Recently, various researchers have proved that approximations of fuzzy numbers may fail to be fuzzy numbers. In this contribution, we suggest a new weighted trapezoidal approximation of an arbitrary fuzzy number, which preserves its cores. We prove that ... Keywords: Core of fuzzy number, Fuzzy numbers, Trapezoidal fuzzy numbers, Weighted approximation

S. Abbasbandy; T. Hajjari

2010-05-01T23:59:59.000Z

142

Curvilinear parabolic approximation for surface wave transformation with wavecurrent interaction  

E-Print Network (OSTI)

Curvilinear parabolic approximation for surface wave transformation with wave­current interaction not be an appropriate method for the purpose of simplifying the curvilinear parabolic approximation of the vector form of the wave­current equation given by Kirby [Higher-order approximations in the parabolic equation method

Kirby, James T.

143

Average Data for Each Choke Setting (before 24-May 2010 06:00), 6-hour average (  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Average Data for Each Choke Setting (before 24-May 2010 06:00), 6-hour average (after 24-May 2010 06:00):" Average Data for Each Choke Setting (before 24-May 2010 06:00), 6-hour average (after 24-May 2010 06:00):" ,,"Choke","Average","Average","Fluid","Methanol","Water","Oil","Gas","Hyd. Eq.","Gas" ,"Choke","Setting","Upstream","Upstream","Recovery","Recovery","Recovery","Recovery","Recovery","Recovery","Recovery" "Date and Time","Setting","Duration","Pressure","Temp.","Rate","Rate","Rate","Rate","Rate","Rate","Portion" "dd-mmm-yy","(64ths)","(hours)","(psia)","(degF)","(bfpd)","(bfpd)","(bwpd)","(bopd)","(mmcfpd)","(boepd)","(%)"

144

Nonprofit Organizations: Have Your Los Alamos Employees/Retirees Log Hours  

NLE Websites -- All DOE Office Websites (Extended Search)

Nonprofit Organizations: Have Your Los Alamos Employees/Retirees Log Nonprofit Organizations: Have Your Los Alamos Employees/Retirees Log Hours in VolunteerMatch Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit Nonprofit Organizations: Have Your Los Alamos Employees/Retirees Log Hours in VolunteerMatch Lab employees and retirees should log their VolunteerMatch hours to benefit local nonprofits. March 1, 2013 Volunteers help fill sandbags during flood season Volunteers help in many different roles including in healthcare. Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email So far, employees and retirees have volunteered more than 1.2 million volunteer hours. If you are a nonprofit organization that has Lab employees or retirees as

145

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Nepal from DLR Nepal from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2002 and 2003 for selected sites in Nepal. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DLR DNI GEF GHI hourly data Nepal NREL solar SWERA TILT UNEP Data application/zip icon Download data (zip, 1.2 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

146

DOE Awards 265 Million Hours of Supercomputing Time to Advance Leading  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Awards 265 Million Hours of Supercomputing Time to Advance DOE Awards 265 Million Hours of Supercomputing Time to Advance Leading Scientific Research Projects DOE Awards 265 Million Hours of Supercomputing Time to Advance Leading Scientific Research Projects January 17, 2008 - 10:38am Addthis WASHINGTON, DC -The U.S. Department of Energy's (DOE) Office of Science today announced that 265 million processor-hours were awarded to 55 scientific projects, the largest amount of supercomputing resource awards donated in the Department's history and three times that of last year's award. The projects-with applications from aeronautics to astrophysics, and from climate change to combustion research-were chosen based on their potential breakthroughs in the science and engineering research and their suitability of the project for using supercomputers. These awards will

147

Spatial and Temporal Characteristics of Heavy Hourly Rainfall in the United States  

Science Conference Proceedings (OSTI)

The climatology of heavy rain events from hourly precipitation observations by Brooks and Stensrud is revisited in this study using two high-resolution precipitation datasets that incorporate both gauge observations and radar estimates. Analyses ...

Nathan M. Hitchens; Harold E. Brooks; Russ S. Schumacher

2013-12-01T23:59:59.000Z

148

DOE's Office of Science Awards 18 Million Hours of Supercomputing Time to  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Office of Science Awards 18 Million Hours of Supercomputing Office of Science Awards 18 Million Hours of Supercomputing Time to 15 Teams for Large-Scale Scientific Computing DOE's Office of Science Awards 18 Million Hours of Supercomputing Time to 15 Teams for Large-Scale Scientific Computing February 1, 2006 - 11:14am Addthis WASHINGTON, D.C. - Secretary of Energy Samuel W. Bodman announced today that DOE's Office of Science has awarded a total of 18.2 million hours of computing time on some of the world's most powerful supercomputers to help researchers in government labs, universities, and industry working on projects ranging from designing more efficient engines to better understanding Parkinson's disease. The allocations of computing time are made under DOE's Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program, now in its

149

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Sri Lanka sites from DLR Sri Lanka sites from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2002 and 2003 for selected sites in Sri Lanka. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DLR DNI GHI hourly data solar Sri Lanka SWERA TILT UNEP Data application/zip icon Download data (zip, 368.2 KiB) Quality Metrics Level of Review Some Review Comment

150

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Ghana from DLR Ghana from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2001 and 2002 for selected sites in Ghana. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DLR DNI Ghana GHI hourly data solar SWERA TILT TMY UNEP Data application/zip icon ghanaDLRtimeseries_103.zip (zip, 2.7 MiB) Quality Metrics Level of Review Some Review Comment

151

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Bangladesh sites from DLR Bangladesh sites from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2002 and 2003 for selected sites in Bangladesh. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords Bangladesh DLR DNI GHI hourly data solar SWERA UNEP Data application/zip icon Download Data (zip, 1.2 MiB) Quality Metrics Level of Review Some Review Comment

152

Pantex celebrates three million hours without a lost time injury | National  

NLE Websites -- All DOE Office Websites (Extended Search)

three million hours without a lost time injury | National three million hours without a lost time injury | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > Pantex celebrates three million hours without a ... Pantex celebrates three million hours without a lost time injury Posted By Office of Public Affairs NNSA Blog NNSA Blog

153

DOE Awards 265 Million Hours of Supercomputing Time to Advance Leading  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

265 Million Hours of Supercomputing Time to Advance 265 Million Hours of Supercomputing Time to Advance Leading Scientific Research Projects DOE Awards 265 Million Hours of Supercomputing Time to Advance Leading Scientific Research Projects January 17, 2008 - 10:38am Addthis WASHINGTON, DC -The U.S. Department of Energy's (DOE) Office of Science today announced that 265 million processor-hours were awarded to 55 scientific projects, the largest amount of supercomputing resource awards donated in the Department's history and three times that of last year's award. The projects-with applications from aeronautics to astrophysics, and from climate change to combustion research-were chosen based on their potential breakthroughs in the science and engineering research and their suitability of the project for using supercomputers. These awards will

154

Commercial and Residential Hourly Load Data Now Available on OpenEI! |  

Open Energy Info (EERE)

Commercial and Residential Hourly Load Data Now Available on OpenEI! Commercial and Residential Hourly Load Data Now Available on OpenEI! Home > Groups > Utility Rate Sfomail's picture Submitted by Sfomail(48) Member 17 May, 2013 - 12:03 building load building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL I am pleased to announce that simulated hourly residential and commercial building load datasets are now available on OpenEI. These datasets are available for all TMY3 locations in the United States. They contain hourly load profile data for 16 commercial building types (based off the DOE commercial reference building models) and residential buildings (based off the Building America House Simulation Protocols). In addition to various

155

Oak Ridge: Approaching 4 Million Safe Work Hours | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ridge: Approaching 4 Million Safe Work Hours Ridge: Approaching 4 Million Safe Work Hours Oak Ridge: Approaching 4 Million Safe Work Hours March 11, 2013 - 12:03pm Addthis Safety inspections are a key element in a nuclear cleanup environment with large pieces of cleanup equipment. Inspections are essential to continuing safety success and reaching new milestones.| Photo courtesy of Oak Ridge Safety inspections are a key element in a nuclear cleanup environment with large pieces of cleanup equipment. Inspections are essential to continuing safety success and reaching new milestones.| Photo courtesy of Oak Ridge David Sheeley Editor/Writer for Environmental Management's Office of External Affairs Workers at URS | CH2M Oak Ridge (UCOR), the prime contractor for EM's Oak Ridge cleanup, are approaching a milestone of 4 million safe work hours

156

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Ethiopia from DLR Ethiopia from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2001 and 2002 for selected sites in Ethiopia. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DLR DNI GHI hourly data solar SWERA TILT UNEP Data application/zip icon Download data (zip, 2.1 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

157

WIPP Workers Reach Two Million Man-Hours Without a Lost-Time Accident  

NLE Websites -- All DOE Office Websites (Extended Search)

Workers Reach Two Million Man-Hours Workers Reach Two Million Man-Hours Without a Lost-Time Accident CARLSBAD, N.M., February 22, 2001 - Workers at the U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) reached a safety milestone Feb. 19 by working two million man-hours without a lost-time accident. According to the National Safety Council, facilities with the same industry code as WIPP lose an average of 20.6 workdays (or 164.8 man-hours) a year to accidents. "Safety is at the core of all WIPP operations," said Dr. Inés Triay, Manager of DOE's Carlsbad Field Office. "We are particularly pleased that WIPP workers reached the two million mark during the time in which they mined a new panel and increased shift work." "To make safety a number one priority means more than creating a safe

158

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

Kenya from DLR Kenya from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2001 and 2002 for selected sites in Kenya. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords DLR DNI GEF GHI hourly data Kenya solar SWERA TILT UNEP Data application/zip icon Download data (zip, 3.9 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

159

DOE's Office of Science Awards 95 Million Hours of Supercomputing Time to  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

95 Million Hours of Supercomputing 95 Million Hours of Supercomputing Time to Advance Research in Science, Academia and Industry DOE's Office of Science Awards 95 Million Hours of Supercomputing Time to Advance Research in Science, Academia and Industry January 8, 2007 - 9:59am Addthis WASHINGTON, D.C. - The U.S. Department of Energy's (DOE) Office of Science announced today that 45 projects were awarded a total of 95 million hours of computing time on some of the world's most powerful supercomputers as part of its 2007 Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. DOE's Under Secretary for Science Dr. Raymond Orbach presented the awards at the Council on Competitiveness in Washington, DC. Supercomputers are playing an increasingly important role in scientific

160

A simple method to downscale daily wind statistics to hourly wind data  

E-Print Network (OSTI)

Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the overall agreement between observed and simulated cumulative wind speed probability distributions appears excellent, especially for the wind speeds greater than 5 m s-1 range (erosive wind speed). The results further revealed that the values of daily average erosive wind power density (AWPD) calculated from generated wind speeds fit the counterparts computed from measured wind speeds well with high models' efficiency (Nash-Sutcliffe coefficient). So that the hourly wind speed data can be predicted from daily average and maximu...

Guo, Zhongling

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

The Relationships between Network Lightning Surface and Hourly Observations of Thunderstorms  

Science Conference Proceedings (OSTI)

Relationships were established between lightning location data and surface hourly observations of thunderstorms for 132 stations in the northeastern United States. The relationships are based on statistics derived from 2 × 2 contingency tables ...

Ronald M. Reap; Richard E. Orville

1990-01-01T23:59:59.000Z

162

Building Technologies Program: Tax Deduction Qualified Software- Hourly Analysis Program (HAP) version 4.41  

Energy.gov (U.S. Department of Energy (DOE))

Provides required documentation that Hourly Analysis Program (HAP) version 4.41 meets Internal Revenue Code §179D, Notice 2006-52, dated April 10, 2009, for calculating commercial building energy and power cost savings.

163

Building Technologies Program: Tax Deduction Qualified Software- Hourly Analysis Program (HAP) version 4.31  

Energy.gov (U.S. Department of Energy (DOE))

Provides required documentation that Hourly Analysis Program (HAP) version 4.31 meets Internal Revenue Code §179D, Notice 2006-52, dated June 2, 2006, for calculating commercial building energy and power cost savings.

164

Cluster Analysis of Hourly Wind Measurements to Reveal Synoptic Regimes Affecting Air Quality  

Science Conference Proceedings (OSTI)

A clustering algorithm is developed to study hourly, ground-level wind measurements obtained from a network of monitoring stations positioned throughout the San Francisco Bay Area of California. A statistical model based on principal components ...

Scott Beaver; Ahmet Palazoglu

2006-12-01T23:59:59.000Z

165

Building Technologies Program: Tax Deduction Qualified Software- Hourly Analysis Program (HAP) version 4.40  

Energy.gov (U.S. Department of Energy (DOE))

Provides required documentation that Hourly Analysis Program (HAP) version 4.40 meets Internal Revenue Code §179D, Notice 2006-52, dated April 10, 2009, for calculating commercial building energy and power cost savings.

166

Building Technologies Program: Tax Deduction Qualified Software- Hourly Analysis Program (HAP) version 4.34  

Energy.gov (U.S. Department of Energy (DOE))

Provides required documentation that Hourly Analysis Program (HAP) version 4.34 meets Internal Revenue Code §179D, Notice 2006-52, dated June 2, 2006, for calculating commercial building energy and power cost savings.

167

Building Technologies Program: Tax Deduction Qualified Software- Hourly Analysis Program (HAP) version 4.50  

Energy.gov (U.S. Department of Energy (DOE))

Provides required documentation that Hourly Analysis Program (HAP) version 4.50 meets Internal Revenue Code §179D, Notice 2006-52, dated June 2, 2006, for calculating commercial building energy and power cost savings.

168

Improved Quality Assurance for Historical Hourly Temperature and Humidity: Development and Application to Environmental Analysis  

Science Conference Proceedings (OSTI)

Historical hourly surface synoptic (airways) meteorological reports from around the United States have been digitized as part of the NOAA Climate Database Modernization Program. An important component is improvement of quality assurance ...

Daniel Y. Graybeal; Arthur T. DeGaetano; Keith L. Eggleston

2004-11-01T23:59:59.000Z

169

How much carbon dioxide (CO 2 ) is produced per kilowatt-hour ...  

U.S. Energy Information Administration (EIA)

How much carbon dioxide (CO 2) is produced per kilowatt-hour when generating electricity with fossil fuels? You can calculate the amount of CO2 produced per kWh for ...

170

NREL Develops Sub-Hour Solar Power Data Set (Fact Sheet), NREL...  

NLE Websites -- All DOE Office Websites (Extended Search)

Sub-Hour Solar Power Data Set NREL data will help utilities incorporate solar energy into their electric power systems. Large-scale deployment of solar energy requires a favorable...

171

A novel 2-D model approach for the prediction of hourly solar radiation  

Science Conference Proceedings (OSTI)

In this work, a two-dimensional (2-D) representation of the hourly solar radiation data is proposed. The model enables accurate forecasting using image prediction methods. One year solar radiation data that is acquired and collected between August 1, ...

F. Onur Hocaoglu; Ö Nezih Gerek; Mehmet Kurban

2007-06-01T23:59:59.000Z

172

Analysis of Sub-Hourly Ramping Impacts of Wind Energy and Balancing Area Size (Poster)  

DOE Green Energy (OSTI)

WindPower 2008 conference sponsored by AWEA held in Houston, TX on June 1-4 2008. This poster illustrates the data collected for an analysis of sub-hourly ramping impacts of wind energy and balancing area size.

Milligan, M.; Kirby, B.

2008-06-01T23:59:59.000Z

173

Hourly Rainfall Changes in Response to Surface Air Temperature over Eastern Contiguous China  

Science Conference Proceedings (OSTI)

In this study, late-summer rainfall over eastern contiguous China is classified according to hourly intensity and the changes of moderate, intense, and extreme precipitation in response to variation of surface air temperature are analyzed. The e-...

Rucong Yu; Jian Li

2012-10-01T23:59:59.000Z

174

6-Hour to 1-Year Variance of Five Global Precipitation Sets  

Science Conference Proceedings (OSTI)

Three-hourly time series of precipitation from three high-resolution precipitation products [Tropical Rainfall Measuring Mission (TRMM) algorithm 3B-42, the Climate Prediction Center’s morphing method (CMORPH), and the Precipitation Estimation ...

Alex C. Ruane; John O. Roads

2007-08-01T23:59:59.000Z

175

Determination of Semivariogram Models to Krige Hourly and Daily Solar Irradiance in Western Nebraska  

Science Conference Proceedings (OSTI)

In this paper, linear and spherical semivariogram models were determined for use in kriging hourly and daily solar irradiation for every season of the year. The data used to generate the models were from 18 weather stations in western Nebraska. ...

G. G. Merino; D. Jones; D. E. Stooksbury; K. G. Hubbard

2001-06-01T23:59:59.000Z

176

Hour-by-Hour Cost Modeling of Optimized Central Wind-Based Water Electrolysis Production - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 FY 2012 Annual Progress Report DOE Hydrogen and Fuel Cells Program Genevieve Saur (Primary Contact), Chris Ainscough. National Renewable Energy Laboratory (NREL) 15013 Denver West Parkway Golden, CO 80401-3305 Phone: (303) 275-3783 Email: genevieve.saur@nrel.gov DOE Manager HQ: Erika Sutherland Phone: (202) 586-3152 Email: Erika.Sutherland@ee.doe.gov Project Start Date: October 1, 2010 Project End Date: Project continuation and direction determined annually by DOE Fiscal Year (FY) 2012 Objectives Corroborate recent wind electrolysis cost studies using a * more detailed hour-by-hour analysis. Examine consequences of different system configuration * and operation for four scenarios, at 42 sites in five

177

An Approximation Algorithm for Computing a Parsimonious ... - CECM  

E-Print Network (OSTI)

Due to the large number of species in the real data set ? 6808 fungal gene trees from 23 species ? we applied only our approximation algorithm. We observed.

178

Finding approximately rank-one submatrices with the nuclear norm ...  

E-Print Network (OSTI)

Nov 8, 2010 ... Abstract: We propose a convex optimization formulation with the nuclear norm and $\\ell_1$-norm to find a large approximately rank-one ...

179

Hardness and Approximation Results for Lp–Ball Constrained ...  

E-Print Network (OSTI)

Oct 31, 2012... a fundamental research issue is to determine their approximability. ...... R. Saigal, and L. Vandenberghe, editors, Handbook of Semidefinite ...

180

Polynomial time algorithms to approximate mixed volumes within a ...  

E-Print Network (OSTI)

Apr 11, 2007 ... ellipsoid method and a randomized poly-time time algorithm for the approximation of the volume of a convex set. ? gurvits@lanl.gov.

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Table A3. Approximate Heat Content of Petroleum Consumption and ...  

U.S. Energy Information Administration (EIA)

U.S. Energy Information Administration / Annual Energy Review 2011 323 Table A3. Approximate Heat Content of Petroleum Consumption and Biofuels Production, Selected ...

182

Table A3. Approximate Heat Content of Petroleum Consumption and ...  

U.S. Energy Information Administration (EIA)

Table A3. Approximate Heat Content of Petroleum Consumption and Biofuels Production, 1949-2011 (Million Btu per Barrel) Year: Total Petroleum 1 ...

183

Approximating the traffic grooming problem in tree and star networks  

Science Conference Proceedings (OSTI)

We consider the problem of grooming paths in all-optical networks with tree topology so as to minimize the switching cost, measured by the total number of used ADMs. We first present efficient approximation algorithms with approximation factor of 2 ln ... Keywords: add-drop multiplexer (ADM), optical networks, traffic grooming, tree networks, wavelength division multiplexing (WDM)

Michele Flammini; Gianpiero Monaco; Luca Moscardelli; Mordechai Shalom; Shmuel Zaks

2006-06-01T23:59:59.000Z

184

On the progressive iteration approximation property and alternative iterations  

Science Conference Proceedings (OSTI)

This note revisits the progressive iteration approximation property and some recent modifications from the point of view of iterative methods for solving linear systems. In particular we show the connection with the classical Richardson iteration and ... Keywords: GMRES, Interpolation, Iterative methods, Progressive iteration approximation

J. M. Carnicer; J. Delgado; J. M. Peña

2011-12-01T23:59:59.000Z

185

A constrained binary knapsack approximation for shortest path network interdiction  

Science Conference Proceedings (OSTI)

A modified shortest path network interdiction model is approximated in this work by a constrained binary knapsack which uses aggregated arc maximum flow as the objective function coefficient. In the modified shortest path network interdiction problem, ... Keywords: Approximation techniques, Homeland security, Integer programming, Network interdiction

Justin Yates; Kavitha Lakshmanan

2011-11-01T23:59:59.000Z

186

Error estimates for the numerical approximation of Neumann control problems  

Science Conference Proceedings (OSTI)

We continue the discussion of error estimates for the numerical analysis of Neumann boundary control problems we started in Casas et al. (Comput. Optim. Appl. 31:193-219, 2005). In that paper piecewise constant functions were used to approximate the ... Keywords: boundary control, error estimates, numerical approximation, semilinear elliptic equation

Eduardo Casas; Mariano Mateos

2008-04-01T23:59:59.000Z

187

On-line Approximate String Matching in Natural Language  

Science Conference Proceedings (OSTI)

We consider approximate pattern matching in natural language text. We use the words of the text as the alphabet, instead of the characters as in traditional string matching approaches. Hence our pattern consists of a sequence of words. From the algorithmic ... Keywords: Approximate string matching, filtering, natural language processing, phrase matching, word alphabet

Kimmo Fredriksson

2006-09-01T23:59:59.000Z

188

Quantile approximations in auto-regressive portfolio models  

Science Conference Proceedings (OSTI)

This paper develops an analytical approximation for the distribution function of a terminal value of a periodic series of buy-and-hold investments placed over a fixed time horizon for the case when log-returns of assets follow a p-th order vector auto-regressive ... Keywords: Multi-period portfolio return, Taylor conditioned approximation, Vector auto-regressive returns

Aleš Ah?an; Igor Masten; Sašo Polanec; Mihael Perman

2011-02-01T23:59:59.000Z

189

Thermodynamic Consistency of the Anelastic Approximation for a Moist Atmosphere  

Science Conference Proceedings (OSTI)

The primary goal of this paper is to validate the use of the anelastic approximation for fluids with a complex equation of state such as moist air or seawater. The anelastic approximation is based on a leading-order expansion of the equations of ...

Olivier Pauluis

2008-08-01T23:59:59.000Z

190

Reasoning with rough description logics: An approximate concepts approach  

Science Conference Proceedings (OSTI)

The current research progress and the existing problems of uncertain or imprecise knowledge representation and reasoning in description logics are analyzed in this paper. Approximate concepts are introduced to description logics based on rough set theory, ... Keywords: Approximate concepts, Concepts, Description logics, Rough description logics, Rough set theory

Yuncheng Jiang; Ju Wang; Suqin Tang; Bao Xiao

2009-02-01T23:59:59.000Z

191

Neural Acceleration for General-Purpose Approximate Programs  

Science Conference Proceedings (OSTI)

This paper describes a learning-based approach to the acceleration of approximate programs. We describe the \\emph{Parrot transformation}, a program transformation that selects and trains a neural network to mimic a region of imperative code. After the ... Keywords: Approximate Computing, Neural Networks, Accelerator, Neural Processing Unit, NPU

Hadi Esmaeilzadeh; Adrian Sampson; Luis Ceze; Doug Burger

2012-12-01T23:59:59.000Z

192

Approximating Selective Sweeps by Richard Durrett and Jason Schweinsberg  

E-Print Network (OSTI)

Approximating Selective Sweeps by Richard Durrett and Jason Schweinsberg Dept. of Math, Cornell U of selective sweeps on genealogies. However, most subsequent work has simplified their approach by assuming that the impact of a selective sweep can be accurately approximated by a random partition created by a stick

Durrett, Richard

193

An approximation algorithm for convex multi-objective programming problems  

Science Conference Proceedings (OSTI)

In multi-objective convex optimization it is necessary to compute an infinite set of nondominated points. We propose a method for approximating the nondominated set of a multi-objective nonlinear programming problem, where the objective functions and ... Keywords: ?-nondominated point, Approximation algorithm, Convex optimization, Multi-objective optimization

Matthias Ehrgott; Lizhen Shao; Anita Schöbel

2011-07-01T23:59:59.000Z

194

Prediction of clock time hourly global radiation from daily values over  

Open Energy Info (EERE)

Prediction of clock time hourly global radiation from daily values over Prediction of clock time hourly global radiation from daily values over Bangladesh Dataset Summary Description (Abstract): A need for predicting hourly global radiation exists for many locations particularly in Bangladesh for which measured values are not available and daily values have to be estimated from sunshine data. The CPRG model has been used to predict values of hourly Gh for Dhaka (23.770N, 90.380E), Chittagong (22.270N, 91.820E) and Bogra (24.850N, 89.370E) for = ±7.50, ±22.50, ±37.50, ±52.50, ±67.50, ±82.50 and ±97.50 i.e., for ±1/2, ±3/2, ±5/2, ±7/2, ±9/2, ±11/2, ±13/2 hours before and after solar noon and the computed values for different months are symmetrical about solar noon whereas for many months experimental data show a clear asymmetry. To obtain improved

195

NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate Change  

NLE Websites -- All DOE Office Websites (Extended Search)

NOAA Awarded 2.6 NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate Change Models NOAA Awarded 2.6 Million Processor Hours at NERSC to Run Climate Change Models September 11, 2008 WASHINGTON, DC - The U.S. Department of Energy's (DOE) Office of Science will make available more than 10 million hours of computing time for the U.S. Commerce Department's National Oceanic and Atmospheric Administration (NOAA) to explore advanced climate change models at three of DOE's national laboratories as part of a three-year memorandum of understanding on collaborative climate research signed today by the two agencies. NOAA will work with climate change models as well as perform near real-time high-impact (non-production) weather prediction research using computing time on DOE Office of Science resources including two of the world's top

196

Solar: hourly global horizontal (GHI) and direct normal (DNI) data for  

Open Energy Info (EERE)

China sites from DLR China sites from DLR Dataset Summary Description (Abstract): Hourly time series of GHI and DNI for the years 2000, 2002 and 2003 for selected sites in China. The hourly data are stored in ASCII files for each station. Please read the documentation file for additional information. (Purpose): For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems. Source DLR - Deutsches Zentrum für Luft- und Raumfahrt Date Released October 31st, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords China DLR DNI GEF GHI solar SWERA UNEP Data application/zip icon Download Data (zip, 953.6 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

197

Oak Ridge: Approaching 4 Million Safe Work Hours | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oak Ridge: Approaching 4 Million Safe Work Hours Oak Ridge: Approaching 4 Million Safe Work Hours Oak Ridge: Approaching 4 Million Safe Work Hours February 27, 2013 - 12:00pm Addthis Mike Tidwell performs a leak check and inspection on propane tanks Mike Tidwell performs a leak check and inspection on propane tanks Inspections ensure hoisting and rigging equipment performs correctly so employees can safely complete their tasks Inspections ensure hoisting and rigging equipment performs correctly so employees can safely complete their tasks Mike Tidwell performs a leak check and inspection on propane tanks Inspections ensure hoisting and rigging equipment performs correctly so employees can safely complete their tasks OAK RIDGE, Tenn. - Workers at URS | CH2M Oak Ridge (UCOR), the prime contractor for EM's Oak Ridge cleanup, are approaching a milestone of 4

198

On a QUEST to Save Oakland 8.4 Gigawatt Hours | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

On a QUEST to Save Oakland 8.4 Gigawatt Hours On a QUEST to Save Oakland 8.4 Gigawatt Hours On a QUEST to Save Oakland 8.4 Gigawatt Hours August 13, 2010 - 3:38pm Addthis Lorelei Laird Writer, Energy Empowers Derrick Rebello wants to make the downtown corridor of Oakland, California, one of the greenest in the nation. Through the new Downtown Oakland Targeted Measure Saturation Project, he and his company, Quantum Energy Services and Technologies (QUEST), are targeting the city's 120-block business district to make as many buildings as possible highly energy efficient. "The goal is to really leave no stone unturned," said Rebello, president of QUEST. "We are trying to achieve 80 percent participation. And of those participating buildings, we are focusing on getting a 20 percent reduction

199

Developing hourly weather data for locations having only daily weather data  

Science Conference Proceedings (OSTI)

A methodology was developed to modify an hourly TMY weather tape to be representative of a location for which only average daily weather parameters were avilable. Typical hourly and daily variations in solar flux, and other parameters, were needed to properly exercise a computer model to predict the transient performance of a solar controlled greenhouse being designed for Riyadh, Saudi Arabia. The starting point was a TMY tape for Yuma, Arizona, since the design temperatures for summer and winter are nearly identical for Yuma and Riyadh. After comparing six of the most important weather variables, the hourly values on the Yuma tape were individually adjusted to give the same overall daily average conditions as existed in the long-term Riyadh data. Finally, a statistical analysis was used to confirm quantitatively that the daily variations between the long term average values for Riyadh and the modified TMY weather tape for Yuma matched satisfactorily.

Talbert, S.G.; Herold, K.E.; Jakob, F.E.; Lundstrom, D.K.

1983-06-01T23:59:59.000Z

200

Sub-Hour Solar Data for Power System Modeling From Static Spatial Variability Analysis: Preprint  

Science Conference Proceedings (OSTI)

High penetration renewable integration studies need high quality solar power data with spatial-temporal correlations that are representative of a real system. This paper will summarize the research relating sequential point-source sub-hour global horizontal irradiance (GHI) values to static, spatially distributed GHI values. This research led to the development of an algorithm for generating coherent sub-hour datasets that span distances ranging from 10 km to 4,000 km. The algorithm, in brief, generates synthetic GHI values at an interval of one-minute, for a specific location, using SUNY/Clean Power Research, satellite-derived, hourly irradiance values for the nearest grid cell to that location and grid cells within 40 km.

Hummon, M.; Ibanez, E.; Brinkman, G.; Lew, D.

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Amp-hour counting charge control for photovoltaic hybrid power systems  

SciTech Connect

An amp-hour counting battery charge control algorithm has been defined and tested using the Digital Solar Technologies MPR-9400 microprocessor based photovoltaic hybrid charge controller. This work included extensive laboratory and field testing of the charge algorithm on vented lead-antimony and valve regulated lead-acid batteries. The test results have shown that with proper setup amp-hour counting charge control is more effective than conventional voltage regulated sub-array shedding in returning the lead-acid battery to a high state of charge.

Hund, T.D. [Sandia National Labs., Albuquerque, NM (United States); Thompson, B. [Biri Systems, Ithaca, NY (United States)

1997-10-01T23:59:59.000Z

202

Vehicle Sharing System Pricing Regulation: A Fluid Approximation  

E-Print Network (OSTI)

to reduce traffic congestion (parking issues), noise, and air pollution (using bikes or electric cars.1 Context Shoup [20] reports that, based on a sample of 22 US studies, cars looking for a parking spot contribute to 30% of the city traffic. Moreover most cars are not in use 90% of the time (use 2 hours per day

203

Vehicle Sharing System Pricing Regulation: A Fluid Approximation  

E-Print Network (OSTI)

or electric cars). They offer personal mobility allowing users to pay only for the usage. We are interested.1 Context Shoup (2005) reports that, based on a sample of 22 US studies, cars looking for a parking spot contribute to 30% of the city traffic. Moreover cars are used less than 2 hours per day on average but still

204

Approximate Coulomb distortion effects in (e,e'p) reactions  

E-Print Network (OSTI)

In this paper we apply a well-tested approximation of electron Coulomb distortion effects to the exclusive reaction (e,e'p) in the quasielastic region. We compare the approximate treatment of Coulomb distortion effects to the exact distorted wave Born approximation evaluated by means of partial wave analysis to gauge the quality of our approximate treatment. We show that the approximate M\\"oller potential has a plane-wave-like structure and hence permits the separation of the cross section into five terms which depend on bilinear products of transforms of the transition four current elements. These transforms reduce to Fourier transforms when Coulomb distortion is not present, but become modified with the inclusion of Coulomb distortion. We investigate the application of the approximate formalism to a model of 208Pb(e,e'p) using Dirac-Hartree single particle wave functions for the ground state and relativistic optical model wave functions for the continuum proton. We show that it is still possible to extract, albeit with some approximation, the various structure functions from the experimentally measured data even for heavy nuclei.

K. S. Kim; L. E. Wright

2005-03-30T23:59:59.000Z

205

NETL: News Release - DOE Awards Local Researcher with 3 Million Hours on  

NLE Websites -- All DOE Office Websites (Extended Search)

8, 2008 8, 2008 DOE Awards Local Researcher with 3 Million Hours on Premier Supercomputer Morgantown, W.Va.-The U.S. Department of Energy's (DOE) Office of Science announced today that a scientist at DOE's National Energy Technology Laboratory (NETL) has been awarded 3 million hours of processor time to conduct advanced research on fossil fuel power plants on one of the world's most powerful supercomputers. http://energy.gov/news/5849.htm The Office of Science awarded the supercomputer hours to Madhava Syamlal, a scientist at NETL, as one of 55 nationwide recipients who received a total of 265 million processor hours. Syamlal, along with his team of co-investigators, will use the powerful Cray XT4 supercomputer at ORNL to vastly increase the speed of coal gasifier simulations to aid in the design and optimization of the power plants. His team is composed of Thomas O'Brien (NETL), Chris Guenther (NETL), Sreekanth Pannala (ORNL), Ramanan Sankaran (ORNL), and Aytekin Gel (Aeolus Research Inc.).

206

Thirty states sign ITER nuclear fusion plant deal 1 hour, 28 minutes ago  

E-Print Network (OSTI)

than 30 countries signed a deal on Tuesday to build the world's most advanced nuclear fusion reactor nuclear reactors, but critics argue it could be at least 50 years before a commercially viable reactorThirty states sign ITER nuclear fusion plant deal 1 hour, 28 minutes ago Representatives of more

207

NREL RSF Weather Data 2011 A csv containing hourly weather data...  

Open Energy Info (EERE)

NREL RSF Weather Data 2011 A csv containing hourly weather data at NREL's Research and Support Facility (RSF) for 2011. 2013-02-12T18:36:26Z 2013-02-12T18:36:26Z I am submitting...

208

Predicting Future Hourly Residential Electrical Consumption: A Machine Learning Case Study  

E-Print Network (OSTI)

(e.g., HVAC) for a specific building, optimizing control systems and strategies for a buildingPredicting Future Hourly Residential Electrical Consumption: A Machine Learning Case Study Richard building energy modeling suffers from several factors, in- cluding the large number of inputs required

Tennessee, University of

209

Sams Teach Yourself Paint Shop Pro 6 in 24 Hours, 1st edition  

Science Conference Proceedings (OSTI)

From the Publisher:This easily accessible tutorial uses a friendly, conversational approach to teach you the basics of Paint Shop Pro 6. With its careful, step-by-step approach, Sams Teach Yourself Paint Shop Pro 6 in 24 Hours makes it easy even for ...

T. Michael Clark; Michael Clark / Kris Tufto

1999-11-01T23:59:59.000Z

210

REDCap 102 Training Session This two-hour session presented by Heather Kim  

E-Print Network (OSTI)

at Vanderbilt. This version of REDCap is main- tained by the UIC Design and Analysis Core, and is offeredREDCap 102 Training Session This two-hour session presented by Heather Kim will explore some Capture) is a secure, web- based application for building and managing online databases for the collection

Illinois at Chicago, University of

211

REDCap 102 Training Session This two-hour session presented by John O'Keefe  

E-Print Network (OSTI)

REDCap team at Vanderbilt. This version of REDCap is main- tained by the UIC Design and Analysis CoreREDCap 102 Training Session This two-hour session presented by John O'Keefe will explore some Data Capture) is a secure, web- based application for building and managing online databases

Illinois at Chicago, University of

212

Climatology of Heavy Rain Events in the United States from Hourly Precipitation Observations  

Science Conference Proceedings (OSTI)

Flash flooding is frequently associated with heavy precipitation (defined here as ?1 in. h?1) occurring over a short period of time. To begin a study of flash flood–producing rain events, the Hourly Precipitation Dataset (HPD) is used to develop ...

Harold E. Brooks; David J. Stensrud

2000-04-01T23:59:59.000Z

213

From the Big Bang to the Higgs Boson in Less Than an Hour  

E-Print Network (OSTI)

From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong) photon Z boson W bosons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum

Fygenson, Deborah Kuchnir

214

From the Big Bang to the Higgs Boson in Less Than an Hour  

E-Print Network (OSTI)

From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D neutrino Z0 W + W -g gluon (8) photon Z boson W bosons Quarks Leptons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong force EM force Weak force #12;Par7cles

Fygenson, Deborah Kuchnir

215

Fuel Cell Stacks Still Going Strong After 5,000 Hours  

Energy.gov (U.S. Department of Energy (DOE))

Two fuel cell stacks developed by FuelCell Energy in partnership with Versa Power Systems achieved 5,000 hours of service in February, meeting a goal of the U.S. Department of Energy's Solid State Energy Conversion Alliance.

216

EMERGENCY CONTACTS for DOWNER LAB Contact Phone After Hours Purpose/Additional Info  

E-Print Network (OSTI)

EMERGENCY CONTACTS for DOWNER LAB Contact Phone After Hours Purpose/Additional Info UT Police.utexas.edu/facilities/services for further information and non-emergency service request forms) Environmental Health & Safety 471-3511 911 emergencies, call 911 or go to a local hospital emergency room. (see healthyhorns.utexas.edu/emergencies

Shvets, Gennady

217

Development of global hourly 0.5-degree land surface air temperature datasets  

Science Conference Proceedings (OSTI)

Land surface air temperature (SAT) is one of the most important variables in weather and climate studies, and its diurnal cycle and day-to-day variation are also needed for a variety of applications. Global long-term hourly SAT observational data, ...

Aihui Wang; Xubin Zeng

218

Development of Global Hourly 0.5° Land Surface Air Temperature Datasets  

Science Conference Proceedings (OSTI)

Land surface air temperature (SAT) is one of the most important variables in weather and climate studies, and its diurnal cycle is also needed for a variety of applications. Global long-term hourly SAT observational data, however, do not exist. ...

Aihui Wang; Xubin Zeng

2013-10-01T23:59:59.000Z

219

WKBJ Approximation of the Stability of a Frontal Mean State  

Science Conference Proceedings (OSTI)

The baroclinic instability of a frontal mean state is investigated using the WKBJ approximation. The results are compared with numerical calculations performed on the same mean state. Excellent agreement (within 5%) is found for jets whose half-...

Petros Ioannou; Richard S. Lindzen

1990-12-01T23:59:59.000Z

220

An empirical comparison of some approximate methods for graph coloring  

Science Conference Proceedings (OSTI)

The Graph Coloring Problem (GCP) is a classical NP-complete problem for which several approximate solution algorithms have been proposed: Brelaz algorithm, simulated annealing (SA), ant colony optimization (ACO). This paper reports empirical results ... Keywords: graph coloring, gravitational swarm

Israel Rebollo-Ruiz; Manuel Graña

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

The Approximating Hamiltonian Method for the Imperfect Boson Gas  

E-Print Network (OSTI)

The pressure for the Imperfect (Mean Field) Boson gas can be derived in several ways. The aim of the present note is to provide a new method based on the Approximating Hamiltonian argument which is extremely simple and very general.

Joseph V. Pule; Valentin A. Zagrebnov

2004-05-14T23:59:59.000Z

222

Approximate expressions for polar gap electric field of pulsars  

E-Print Network (OSTI)

We derive easy-to-handle approximations for the polar gap electric field due to inertial frame dragging as derived by Harding & Muslimov 1998. A simple formula valid for polar gap height comparable to the polar cap radius is presented.

J. Dyks; B. Rudak

2000-06-19T23:59:59.000Z

223

Testing and Comparing the Modified Anomalous Diffraction Approximation  

Science Conference Proceedings (OSTI)

The modified anomalous diffraction approximation (MADA) is used to predict absorption and extinction in water and ice clouds, but it does not predict the scattering phase function or asymmetry parameter g. In conjunction with g parameterizations, ...

David L. Mitchell; Anthony J. Baran; W. P. Arnott; C. Schmitt

2006-11-01T23:59:59.000Z

224

Numerical Tests of the Weak Pressure Gradient Approximation  

Science Conference Proceedings (OSTI)

Cloud-resolving simulations of convection over a surface temperature hot spot are used to evaluate the weak pressure gradient (WPG) and weak temperature gradient (WTG) approximations. The premise of the relaxed form of WTG—that vertical velocity ...

David M. Romps

2012-09-01T23:59:59.000Z

225

Approximate translation : media, narrative, and experience in urban design  

E-Print Network (OSTI)

Approximate translation is developed as a design process through which the place-embedded history of an urban environment can be understood, allowing for better design and intervention in that urban environment. Generally, ...

Crisman, Jonathan

2013-01-01T23:59:59.000Z

226

Relativistic plasma dispersion functions: Series, integrals, and approximations  

SciTech Connect

A number of results are presented involving the plasma dispersion functions appropriate to waves in weakly relativistic, magnetized, thermal plasmas. These results include generating functions, series, integral forms and interrelations, and several useful approximations.

Robinson, P.A.

1987-05-01T23:59:59.000Z

227

Statistical theory of Langmuir turbulence. [Direct interaction approximation  

SciTech Connect

A statistical theory of Langmuir turbulence is developed by applying a generalization of the direction interaction approximation (DIA) of Kraichnan to the Zakharov equations describing Langmuir turbulence. 7 references.

DuBois, D.F.; Rose, H.A.; Goldman, M.V.

1979-01-01T23:59:59.000Z

228

A Practical Approximation to Optimal Four-Dimensional Objective Analysis  

Science Conference Proceedings (OSTI)

An iterative four-dimensional objective analysis scheme is described. The method is derived by approximating a variational algorithm which should give an optimal four-dimensional analysis The complete set of operationally available observations, ...

Andrew C. Lorenc

1988-03-01T23:59:59.000Z

229

A discrete BGK approximation for strongly degenerate parabolic problems  

E-Print Network (OSTI)

A discrete BGK approximation for strongly degenerate parabolic problems with boundary conditions F strongly degenerate hyperbolic--parabolic equations with initial boundary condition. We prove a priori -- strongly degenerate parabolic equations -- singular perturbation problems -- BGK models 1 Introduction

230

Approximate query answering in unstructured peer-to-peer databases.  

E-Print Network (OSTI)

??Peer-to-peer networks are considered the new generation of distributed databases, termed peer-to-peer databases. With very large size, open architecture, and extreme dynamism and autonomy, approximate… (more)

Banaei-Kashani, Farnoush

2007-01-01T23:59:59.000Z

231

On the Median Volume Diameter Approximation for Droplet Collision Efficiency  

Science Conference Proceedings (OSTI)

In this note, we examine a shortcut for calculating the overall collision efficiency of a droplet spectrum, known as the “median volume diameter” (mvd) approximation. By calculating the overall collision efficiency of a circular cylinder for a ...

Karen J. Finstad; Edward P. Lozowski; Lasse Makkonen

1988-12-01T23:59:59.000Z

232

A Free-Algebraic Solution for the Planar Approximation  

E-Print Network (OSTI)

An explicit solution for the generating functional of n-point functions in the planar approximation is given in terms of two sets of free-algebraic annihilation and creation operators.

O. Haan

2004-08-11T23:59:59.000Z

233

On Safe Tractable Approximations of Chance Constrained Linear ...  

E-Print Network (OSTI)

†Faculty of Industrial Engineering and Management, Technion – Israel Institute of Technology, ... its scenario approximation is the random optimization program min x. { f0(x) : fi(x ..... We generate a training sample of N independent realizations.

234

Approximation algorithms for stochastic scheduling on unrelated machines  

E-Print Network (OSTI)

Motivated by problems in distributed computing, this thesis presents the first nontrivial polynomial time approximation algorithms for an important class of machine scheduling problems. We study the family of preemptive ...

Scott, Jacob (Jacob Healy)

2008-01-01T23:59:59.000Z

235

Linear Baroclinic instability with the Geostrophic Momentum Approximation  

Science Conference Proceedings (OSTI)

The linear Eady model of baroclinic instability with the geostrophic momentum (GM) approximation is solved analytically in physical space and shown to be identical to linear three-dimensional semigeostrophic theory. Both the growth rates and the ...

Peter R. Bannon

1989-02-01T23:59:59.000Z

236

Potential Vorticity Conservation, Hydrostatic Adjustment, and the Anelastic Approximation  

Science Conference Proceedings (OSTI)

An examination of the anelastic equations of Lipps and Hemler shows that the approximation requires the temperature and potential temperature scale heights of the base state are large compared to the pressure and density scale heights. As a ...

Peter R. Bannon

1995-06-01T23:59:59.000Z

237

Approximate dynamic programming with applications in multi-agent systems  

E-Print Network (OSTI)

This thesis presents the development and implementation of approximate dynamic programming methods used to manage multi-agent systems. The purpose of this thesis is to develop an architectural framework and theoretical ...

Valenti, Mario J. (Mario James), 1976-

2007-01-01T23:59:59.000Z

238

Approximating the traffic grooming problem in tree and star networks  

Science Conference Proceedings (OSTI)

We consider the problem of grooming paths in all-optical networks with tree topology so as to minimize the switching cost, measured by the total number of used ADMs. We first present efficient approximation algorithms with approximation factor of 2ln(@d@?g)+o(ln(@d@?g)) ... Keywords: Add-drop multiplexer (ADM), Optical networks, Traffic grooming, Tree networks, Wavelength division multiplexing (WDM)

Michele Flammini; Gianpiero Monaco; Luca Moscardelli; Mordechai Shalom; Shmuel Zaks

2008-07-01T23:59:59.000Z

239

Indexing methods for approximate dictionary searching: Comparative analysis  

Science Conference Proceedings (OSTI)

The primary goal of this article is to survey state-of-the-art indexing methods for approximate dictionary searching. To improve understanding of the field, we introduce a taxonomy that classifies all methods into direct methods and sequence-based filtering ... Keywords: k-errata tree, q-gram, q-sample, Damerau-Levenshtein distance, Levenshtein distance, NR-grep, agrep, approximate searching, frequency distance, frequency vector trie, metric trees, neighborhood generation, trie

Leonid Boytsov

2011-05-01T23:59:59.000Z

240

Building Technologies Program: Tax Deduction Qualified Software - Hourly Analysis Program (HAP) version 4.40  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hourly Analysis Program (HAP) version 4.40.0.61 Hourly Analysis Program (HAP) version 4.40.0.61 On this page you'll find information about the HAP version 4.40.0.61 qualified computer software (buildings.energy.gov/qualified_software.html), which calculates energy and power cost savings that meet federal tax incentive requirements for commercial buildings. Date Documentation Received by DOE: 10 April 2009 Statements in quotes are from the software developer. Internal Revenue Code §179D (c)(1) and (d) Regulations Notice 2006-52, Section 6 requirements as amplified by Notice 2008-40, Section 4 requirements. (1) The name, address, and (if applicable) web site of the software developer; Carrier / United Technologies Corporation Carrier Software Systems Bldg TR-4, Room 400A P. O. Box 4808 Syracuse, New York 13221

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Effects of electric utility residential conservation programs on hourly load profiles  

SciTech Connect

This paper discusses the potential of using hourly energy simulation models to determine load shape changes resulting from energy conservation activities. It is determined that shifts in the time and the day of the monthly peak demand may occur as the level of conservation increases. The shifting of the peak was from weather-sensitive periods to less-weather-sensitive periods. Seasonal load profile changes resulting from energy conservation were demonstrated. A statistically significant quadratic relationship was identified between the annual percent reduction and annual percent energy conserved for the different distribution systems examined. The relationships are examined between different levels of residential energy conservation from weatherization and heat pumps on the hourly load profiles of different power distribution systems within the TVA power service area.

Harper, J.P.; Sieber, R.E.

1983-01-01T23:59:59.000Z

242

Building Technologies Program: Tax Deduction Qualified Software - Hourly Analysis Program (HAP) version 4.41  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hourly Analysis Program (HAP) version 4.41.0.6 Hourly Analysis Program (HAP) version 4.41.0.6 On this page you'll find information about the HAP version 4.41.0.6 qualified computer software (buildings.energy.gov/qualified_software.html), which calculates energy and power cost savings that meet federal tax incentive requirements for commercial buildings. Date Documentation Received by DOE: 10 April 2009 Statements in quotes are from the software developer. Internal Revenue Code §179D (c)(1) and (d) Regulations Notice 2006-52, Section 6 requirements as amplified by Notice 2008-40, Section 4 requirements. (1) The name, address, and (if applicable) web site of the software developer; Carrier / United Technologies Corporation Carrier Software Systems Bldg TR-4, Room 400A P. O. Box 4808 Syracuse, New York 13221

243

Six- and Three-Hourly Meteorological Observations from 223 Former U.S.S.R.  

NLE Websites -- All DOE Office Websites (Extended Search)

Six- and Three-Hourly Meteorological Observations from 223 Former U.S.S.R. Six- and Three-Hourly Meteorological Observations from 223 Former U.S.S.R. Stations (NDP-048) DOI: 10.3334/CDIAC/cli.ndp048 image PDF image Data image Previous Data (data through 1990, published in 1998) image Investigators Contributed by V. N. Razuvaev, E. B. Apasova, R. A. Martuganov All-Russian Research Institute of Hydrometeorological Information-World Data Centre Obninsk, Russia Prepared by D. P. Kaiser and G. P. Marino (contact: kaiserdp@ornl.gov) Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Oak Ridge, Tennessee Date Published: November 2007

244

Y-12 Construction hits one million-hour mark without a lost-time accident |  

NLE Websites -- All DOE Office Websites (Extended Search)

Construction hits one ... Construction hits one ... Y-12 Construction hits one million-hour mark without a lost-time accident Posted: August 30, 2012 - 5:30pm The B&W Y-12 Direct-Hire Construction team has worked one million hours, covering a 633-day period, without a lost-time injury. Some 285 people including building trade crafts, non-manual staff and escorts worked without a lost-time accident during this period. The Construction team's last lost workday was in September 2010. A celebration was held today to mark the safety milestone. Senior leaders from National Nuclear Security Administration Production Office (NPO) and B&W Y-12 were on hand to congratulate the workers. Jim Haynes, B&W Y-12 senior vice president and deputy general manager for projects, said, "Congratulations are due the men and women of

245

Hospital Triage in the First 24 Hours after a Nuclear or Radiological Disaster  

NLE Websites -- All DOE Office Websites (Extended Search)

Hospital Triage in the First 24 Hours after a Nuclear or Radiological Disaster Hospital Triage in the First 24 Hours after a Nuclear or Radiological Disaster Berger, ME; Leonard, RB; Ricks, RC; Wiley, AL; Lowry, PC; Flynn, DF Abstract: This article addresses the problems emergency physicians would face in the event of a nuclear or radiological catastrophe. It presents information about what needs to be done so that useful information will be gathered and reasonable decisions made in the all important triage period. A brief introductory explanation of radiation injury is followed by practical guides for managing the focused history, physical exam, laboratory tests, initial treatment, and disposition of victims of acute radiation syndrome and combined injury. The guides are not intended to serve as a hospital's "emergency

246

Hourly analysis of a very large topically categorized web query log  

E-Print Network (OSTI)

We review a query log of hundreds of millions of queries that constitute the total query traffic for an entire week of a generalpurpose commercial web search service. Previously, query logs have been studied from a single, cumulative view. In contrast, our analysis shows changes in popularity and uniqueness of topically categorized queries across the hours of the day. We examine query traffic on an hourly basis by matching it against lists of queries that have been topically pre-categorized by human editors. This represents 13 % of the query traffic. We show that query traffic from particular topical categories differs both from the query stream as a whole and from other categories. This analysis provides valuable insight for improving retrieval effectiveness and efficiency. It is also relevant to the development of enhanced query disambiguation, routing, and caching algorithms.

Steven M. Beitzel; Eric C. Jensen; Abdur Chowdhury; David Grossman; Ophir Frieder

2004-01-01T23:59:59.000Z

247

Day-Ahead/Hour-Ahead Forecasting for Demand Trading: A Guidebook  

Science Conference Proceedings (OSTI)

Demand trading can be an effective hedge against wholesale power price spikes during times of constraint. However, it also can be a high-risk venture. Profitability depends on reliable demand forecasting. Short-term load forecasting (STLF) can minimize the risks of day-ahead purchasing by providing better predictions at the system level. Additionally, STLF can reduce hour-ahead spot market risks and directly support demand trading by providing more accurate assessments of incremental load reductions from...

2001-12-20T23:59:59.000Z

248

Day-Ahead/Hour-Ahead Forecasting for Demand Trading: A Guidebook  

Science Conference Proceedings (OSTI)

Download report 1006016 for FREE. Demand trading can be an effective hedge against wholesale power price spikes during times of constraint. However, it also can be a high-risk venture. Profitability depends on reliable demand forecasting. Short-term load forecasting (STLF) can minimize the risks of day-ahead purchasing by providing better predictions at the system level. Additionally, STLF can reduce hour-ahead spot market risks and directly support demand trading by providing more accurate assessments o...

2001-12-20T23:59:59.000Z

249

The Complexity of Approximating Bounded-Degree Boolean #CSP  

E-Print Network (OSTI)

The degree of a CSP instance is the maximum number of times that a variable may appear in the scope of constraints. We consider the approximate counting problem for Boolean CSPs with bounded-degree instances for constraint languages containing the two unary constant relations {0} and {1}. When the maximum degree is at least 25 we obtain a complete classification of the complexity of this problem. It is exactly solvable in polynomial-time if every relation in the constraint language is affine. It is equivalent to the problem of approximately counting independent sets in bipartite graphs if every relation can be expressed as conjunctions of {0}, {1} and binary implication. Otherwise, there is no FPRAS unless NP=RP. For lower degree bounds, additional cases arise in which the complexity is related to the complexity of approximately counting independent sets in hypergraphs.

Dyer, Martin; Jalsenius, Markus; Richerby, David

2009-01-01T23:59:59.000Z

250

The Monte Carlo Independent Column Approximation Model Intercomparison  

NLE Websites -- All DOE Office Websites (Extended Search)

The Monte Carlo Independent Column Approximation Model Intercomparison The Monte Carlo Independent Column Approximation Model Intercomparison Project (McMIP) Barker, Howard Meteorological Service of Canada Cole, Jason Meteorological Service of Canada Raisanen, Petri Finnish Meteorological Institute Pincus, Robert NOAA-CIRES Climate Diagnostics Center Morcrette, Jean-Jacques European Centre for Medium-Range Weather Forecasts Li, Jiangnan Canadian Center for Climate Modelling Stephens, Graeme Colorado State University Vaillancourt, Paul Environment Canada Oreopoulos, Lazaros JCET/UMBC and NASA/GSFC Siebesma, Pier KNMI Los, Alexander KNMI Clothiaux, Eugene The Pennsylvania State University Randall, David Colorado State University Iacono, Michael Atmospheric & Environmental Research, Inc. Category: Radiation The Monte Carlo Independent Column Approximation (McICA) method for

251

Discrete Variational Calculus for B-spline Approximated Curves  

E-Print Network (OSTI)

We study variational problems for curves approximated by B-spline curves. We show that, one can obtain discrete Euler-Lagrange equations, for the data describing the approximated curves. Our main application is to the curve completion problem in 2D and 3D. In this case, the aim is to find various aesthetically pleasing solutions as opposed to a solution of a physical problem. The Lagrangians of interest are invariant under the special Euclidean group action for which B-spline approximated curves are well suited. Smooth Lagrangians with special Euclidean symmetries involve curvature, torsion, and arc length. Expressions in these, in the original coordinates, are highly complex. We show that, by contrast, relatively simple discrete Lagrangians offer excellent results for the curve completion problem. The methods we develop for the discrete curve completion problem are general and can be used to solve other discrete variational problems for B-spline curves.

Zhao, Jun

2010-01-01T23:59:59.000Z

252

Efficient algorithm for approximating one-dimensional ground states  

Science Conference Proceedings (OSTI)

The density-matrix renormalization-group method is very effective at finding ground states of one-dimensional (1D) quantum systems in practice, but it is a heuristic method, and there is no known proof for when it works. In this article we describe an efficient classical algorithm which provably finds a good approximation of the ground state of 1D systems under well-defined conditions. More precisely, our algorithm finds a matrix product state of bond dimension D whose energy approximates the minimal energy such states can achieve. The running time is exponential in D, and so the algorithm can be considered tractable even for D, which is logarithmic in the size of the chain. The result also implies trivially that the ground state of any local commuting Hamiltonian in 1D can be approximated efficiently; we improve this to an exact algorithm.

Aharonov, Dorit; Arad, Itai; Irani, Sandy [School of Computer Science and Engineering, Hebrew University, Jerusalem (Israel); School of Computer Science, Tel-Aviv University, Tel-Aviv (Israel); Computer Science Department, University of California, Irvine, California (United States)

2010-07-15T23:59:59.000Z

253

An Hourly-Based Performance Comparison of an Integrated Micro-Structural  

NLE Websites -- All DOE Office Websites (Extended Search)

An Hourly-Based Performance Comparison of an Integrated Micro-Structural An Hourly-Based Performance Comparison of an Integrated Micro-Structural Perforated Shading Screen with Standard Shading Systems Title An Hourly-Based Performance Comparison of an Integrated Micro-Structural Perforated Shading Screen with Standard Shading Systems Publication Type Journal Article LBNL Report Number LBNL-5521E Year of Publication 2012 Authors Appelfeld, David, Andrew McNeil, and Svend Svendsen Journal Energy and Buildings Volume 50 Issue July 2012 Keywords building performance modelling, complex fenestration system, daylight, shading, solar gains Abstract This article evaluates the performance of an integrated micro structural perforated shading screen (MSPSS). Such a system maintains a visual connection with the outdoors while imitating the shading functionality of a venetian blind. Building energy consumption is strongly influenced by the solar gains and heat transfer through the transparent parts of the fenestration systems. MSPSS is angular-dependent shading device that provides an effective strategy in the control of daylight, solar gains and overheating through windows. The study focuses on using direct experimental methods to determine bi-directional transmittance properties of shading systems that are not included as standard shading options in readily available building performance simulation tools. The impact on the indoor environment, particularly temperature and daylight were investigated and compared to three other static complex fenestration systems. The bi-directional description of the systems was used throughout the article. The simulations were validated against outdoor measurements of solar and light transmittance.

254

Identifying Challenging Operating Hours for Solar Intergration in the NV Energy System  

Science Conference Proceedings (OSTI)

Abstract-- In this paper, the ability of the Nevada (NV) Energy generation fleet to meet its system balancing requirements under different solar energy penetration scenarios is studied. System balancing requirements include capacity, ramp rate, and ramp duration requirements for load following and regulation. If, during some operating hours, system capability is insufficient to meet these requirements, there is certain probability that the balancing authority’s control and reliability performance can be compromised. These operating hours are considered as “challenging” hours. Five different solar energy integration scenarios have been studied. Simulations have shown that the NV Energy system will be potentially able to accommodate up to 942 MW of solar photovoltaic (PV) generation. However, the existing generation scheduling procedure should be adjusted to make it happen. Fast-responsive peaker units need to be used more frequently to meet the increasing ramping requirements. Thus, the NV Energy system operational cost can increase. Index Terms—Solar Generation, Renewables Integration, Balancing Process, Load Following, Regulation.

Etingov, Pavel V.; Lu, Shuai; Guo, Xinxin; Ma, Jian; Makarov, Yuri V.; Chadliev, Vladimir; Salgo, Richard

2012-05-09T23:59:59.000Z

255

Reliability analysis of solar photovoltaic system using hourly mean solar radiation data  

Science Conference Proceedings (OSTI)

This paper presents the hourly mean solar radiation and standard deviation as inputs to simulate the solar radiation over a year. Monte Carlo simulation (MCS) technique is applied and MATLAB program is developed for reliability analysis of small isolated power system using solar photovoltaic (SPV). This paper is distributed in two parts. Firstly various solar radiation prediction methods along with hourly mean solar radiation (HMSR) method are compared. The comparison is carried on the basis of predicted electrical power generation with actual power generated by SPV system. Estimation of solar photovoltaic power using HMSR method is close to the actual power generated by SPV system. The deviation in monsoon months is due to the cloud cover. In later part of the paper various reliability indices are obtained by HMSR method using MCS technique. Load model used is IEEE-RTS. Reliability indices, additional load hours (ALH) and additional power (AP) reduces exponentially with increase in load indicates that a SPV source will offset maximum fuel when all of its generated energy is utilized. Fuel saving calculation is also investigated. Case studies are presented for Sagardeep Island in West Bengal state of India. (author)

Moharil, Ravindra M. [Department of Electrical Engineering, Yeshwantrao Chavan College of Engineering, Nagpur, Maharashtra (India); Kulkarni, Prakash S. [Department of Electrical Engineering, Visvesvaraya National Institute of Technology, South Ambazari Road, Nagpur 440011, Maharashtra (India)

2010-04-15T23:59:59.000Z

256

approximately 200 megawatts (MWs) of power from TCEP, making  

NLE Websites -- All DOE Office Websites (Extended Search)

approximately 200 megawatts (MWs) of power from TCEP, making approximately 200 megawatts (MWs) of power from TCEP, making it the first U.S. purchase by a utility of low-carbon power from a commercial-scale, coal-based power plant with carbon capture. The 400-MW TCEP plant is a first-of-its-kind integrated gasification combined cycle (IGCC) poly-generation facility capable of capturing 90 percent of the carbon dioxide (CO 2 ) it produces. The $2.4-billion plant was a third round selection under DOE's Clean Coal Power Initiative

257

Are there approximate relations among transverse momentum dependent distribution functions?  

SciTech Connect

Certain {\\sl exact} relations among transverse momentum dependent parton distribution functions due to QCD equations of motion turn into {\\sl approximate} ones upon the neglect of pure twist-3 terms. On the basis of available data from HERMES we test the practical usefulness of one such ``Wandzura-Wilczek-type approximation'', namely of that connecting $h_{1L}^{\\perp(1)a}(x)$ to $h_L^a(x)$, and discuss how it can be further tested by future CLAS and COMPASS data.

Harutyun AVAKIAN; Anatoli Efremov; Klaus Goeke; Andreas Metz; Peter Schweitzer; Tobias Teckentrup

2007-10-11T23:59:59.000Z

258

On k-jet field approximations of geodesic deviation equations  

E-Print Network (OSTI)

Let M be a smooth manifold and S a spray defined on the convex cone C of the tangent bundle TM. It is proved that the only non-trivial k-jet approximation of the exact geodesic deviation equation of S, linear on the deviation functions and invariant under arbitrary local coordinate transformations corresponds to the Jacobi equation. However, if linearity in the deviation functions is not required, there are differential equations whose solutions admit k-jet approximations and are invariant under arbitrary coordinate transformations. As an example of higher order geodesic deviation equations we study the first and second order jet geodesic deviation equations for a Finsler spray.

Torromé, Ricardo Gallego

2013-01-01T23:59:59.000Z

259

QueryLines: approximate query for visual browsing  

E-Print Network (OSTI)

We introduce approximate query techniques for searching and analyzing two-dimensional data sets such as line or scatter plots. Our techniques allow users to explore a dataset by defining QueryLines: soft constraints and preferences for selecting and sorting a subset of the data. By using both preferences and soft constraints for query composition, we allow greater flexibility and expressiveness than previous visual query systems. When the user over-constrains a query, for example, a system using approximate techniques can display ¨near misses¨to enable users to quickly and continuously refine queries.

Kathy Ryall; Neal Lesh; Hiroaki Miyashita; Shigeru Makino; Tom Lanning; Tom Lanning; Darren Leigh; Darren Leigh

2005-01-01T23:59:59.000Z

260

Properties of derivative expansion approximations to the renormalization group  

E-Print Network (OSTI)

Approximation only by derivative (or more generally momentum) expansions, combined with reparametrization invariance, turns the continuous renormalization group for quantum field theory into a set of partial differential equations which at fixed points become non-linear eigenvalue equations for the anomalous scaling dimension $\\eta$. We review how these equations provide a powerful and robust means of discovering and approximating non-perturbative continuum limits. Gauge fields are briefly discussed. Particular emphasis is placed on the r\\^ole of reparametrization invariance, and the convergence of the derivative expansion is addressed.

Tim R. Morris

1996-10-02T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Efficient classical simulation of the approximate quantum Fourier transform  

E-Print Network (OSTI)

We present a method for classically simulating quantum circuits based on the tensor contraction model of Markov and Shi (quant-ph/0511069). Using this method we are able to classically simulate the approximate quantum Fourier transform in polynomial time. Moreover, our approach allows us to formulate a condition for the composability of simulable quantum circuits. We use this condition to show that any circuit composed of a constant number of approximate quantum Fourier transform circuits and log-depth circuits with limited interaction range can also be efficiently simulated.

Nadav Yoran; Anthony J. Short

2006-11-23T23:59:59.000Z

262

Best Approximation in the Mean by Analytic and Harmonic Functions  

E-Print Network (OSTI)

* *ng the annihilator Ann (Hp) in Lq(T, d`)as Hq0= {f 2 Hq : f(0) = 0}, q = __p__pt-u1rns* * out is organized as follows. In Section 2we prove the exi* *stence of best approximations and characterize them

McCarthy, John E.

263

Choosing an Approximation to the Equation of Radiative Transfer  

Science Conference Proceedings (OSTI)

We examine the accuracy of the PL, approximation to the equation of radiative transfer in the presence of scattering/absorbing clouds of various optical thicknesses. We find that very accurate net fluxes can be obtained with the P1, (two-stream) ...

James A. Fillmore; Alan H. Karp

1980-08-01T23:59:59.000Z

264

Hierarchical Structure for function approximation using radial basis function  

Science Conference Proceedings (OSTI)

The hierarchial network proposed (Multi-RBFNN), is composed of complete Radial Basis Function Neural Networks (RBFNNs) that are in charge of a reduced set of input variables with the property of which every Sub-RBFNN can take charge of a set of input ... Keywords: function approximation, hierarchical architectures, input variable selection, radial bases functions

A. Awad; H. Pomares; I. Rojas; L. J. Herrera; A. Guillen; O. Valenzuela

2005-12-01T23:59:59.000Z

265

Asymptotic Approximations to the Distributed Activation Energy Model  

E-Print Network (OSTI)

Asymptotic Approximations to the Distributed Activation Energy Model M.J.McGuinness1 , E. Donskoi2 by a continuum distribution in activation energy of individual re- actions. An individual reaction is characterised by a pre-exponential coefficient and an activation energy. The distribution, usually Gaussian

McGuinness, Mark

266

Uniqueness and Approximated Computation of Optimal Incomplete Transportation Plans  

E-Print Network (OSTI)

Uniqueness and Approximated Computation of Optimal Incomplete Transportation Plans P. C. ´Alvarez Transportation, where a part of the mass could be not necessarily transported. Since optimal transportation plans consistency result. As a remarkable and unexpected additional result, with important implications for future

Cuesta, Juan Antonio

267

On the Approximability of Reachability Preserving Network Orientations  

E-Print Network (OSTI)

On the Approximability of Reachability Preserving Network Orientations Michael Elberfeld Institute@post.tau.ac.il Abstract We introduce a graph orientation problem arising in the study of biological networks. Given an undirected graph and a list of ordered source-target vertex pairs, the goal is to orient the graph

Sharan, Roded

268

Gluon Condensate in Pion Superfluid beyond Mean Field Approximation  

E-Print Network (OSTI)

We study gluon condensate in a pion superfluid, through calculating the equation of state of the system in the Nambu-Jona-Lasinio model. While in mean field approximation the growing pion condensate leads to an increasing gluon condensate, meson fluctuations reduce the gluon condensate and the broken scalar symmetry can be smoothly restored at finite isospin density.

Yin Jiang; Pengfei Zhuang

2010-12-10T23:59:59.000Z

269

Elastic approximation for a solar parabolic February 29, 2012  

E-Print Network (OSTI)

Elastic approximation for a solar parabolic trough February 29, 2012 Gang Xiao (University of Nice, France) Abstract For the production of the reective surface of a solar parabolic trough concentrator energy solutions. Introduction A parabolic trough [8] is a concentrating solar thermal energy collector

Paris-Sud XI, Université de

270

Weak lensing and the Dyer-Roeder approximation  

E-Print Network (OSTI)

The distance-redshift relation plays an important role in cosmology. In the standard approach to cosmology it is assumed that this relation is the same as in the homogeneous universe. As the real universe is not homogeneous there are several methods to calculate the correction. The weak lensing approximation and the Dyer-Roeder relation are one of them. This paper establishes a link between these two approximations. It is shown that if the universe is homogeneous with only small, vanishing after averaging, density fluctuations along the line of sight, then the distance correction is negligible. It is also shown that a vanishing 3D average of density fluctuations does not imply that the mean of density fluctuations along the line of sight is zero. In this case, even within the linear approximation, the distance correction is not negligible. The modified version of the Dyer-Roeder relation is presented and it is shown that this modified relation is consistent with the correction obtained within the weak lensing approximation. The correction to the distance for a source at z ~ 2 is of order of a few percent. Thus, with an increasing precision of cosmological observations an accurate estimation of the distance is essential. Otherwise errors due to miscalculation the distance can become a major source of systematics.

Krzysztof Bolejko

2010-11-17T23:59:59.000Z

271

Matrix Approximation and Projective Clustering via Iterative Sampling  

E-Print Network (OSTI)

We present two new results for the problem of approximating a given real m by n matrix A by a rank-k matrix D, where k < min{m, n}, so as to minimize ||A-D||_F^2. It is known that bysampling O(k/eps) rows of the matrix, ...

Rademacher, Luis

2005-03-29T23:59:59.000Z

272

APPROXIMATE DYNAMIC PROGRAMMING METHODS FOR COOPERATIVE UAV SEARCH  

E-Print Network (OSTI)

APPROXIMATE DYNAMIC PROGRAMMING METHODS FOR COOPERATIVE UAV SEARCH Matthew Flint Emmanuel 01801 matt.flint@baesystems.com Dept. of Electrical and Computer Engineering and Computer Science by the authors of this paper e.g. (Flint et al., 2003b), (Flint et al., 2003a), (Flint et al., 2004); and others

Fernandez, Emmanuel

273

Absorption Approximation with Scattering Effect for Infrared Radiation  

Science Conference Proceedings (OSTI)

A scheme that can handle cloud infrared scattering based on the absorption approximation is developed. In a two-stream mode, the new scheme produces more accurate results than those from the modified two-stream discrete ordinate method. For low ...

J. Li; Qiang Fu

2000-09-01T23:59:59.000Z

274

Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Min Load  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Min Load for 12 hours Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Min Load for 12 hours Docket No. EO-05-01. Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Min Load for 12 hours. Arial photograph showing plant and location of predicted SO2 violations, predicted in 2000. Mirant: Case 67a: Units 3 & 4 & 5 at Max Load for 12 hours and at Min Load for 12 hours More Documents & Publications Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 3, 1, 2 SO2 Case Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 4, 1, 2 SO2 Case Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by

275

Observed Temperature Effects on Hourly Residential Electric Load Reduction in Response to an Experimental Critical Peak Pricing Tariff  

E-Print Network (OSTI)

changes to retail electricity rates on an hourly or dailyweekdays 2004 [6] Most electricity rates in use today arerates with control technologies use 30- 40% less electricity

Herter, Karen B.; McAuliffe, Patrick K.; Rosenfeld, Arthur H.

2005-01-01T23:59:59.000Z

276

Fault Detection of Hourly Measurements in District Heat and Electricity Consumption; Feldetektion av Timinsamlade Mätvärden i Fjärrvärme- och Elförbrukning.  

E-Print Network (OSTI)

?? Within the next years, the amount of consumption data will increase rapidly as old meters will be exchanged in favor of meters with hourly… (more)

Johansson, Andreas

2005-01-01T23:59:59.000Z

277

SCHOOL OF MATHEMATICS AND STATISTICS Spring Semester Time Series 2 hours  

E-Print Network (OSTI)

to University regulations. There are 99 marks available on the paper. Please leave this exam paper on your desk time series and their relationship, using suitable technical terms and adding approximate quanti series model Xt = 1 3 Xt-1 + t + 1 2 t-1 - 1 4 t-2, where t is white noise with variance 4. (i) Explain

Oakley, Jeremy

278

Fine-grained efficient resource allocation using approximated combinatorial auctions: A parallel greedy winner approximation for large-scale problems  

Science Conference Proceedings (OSTI)

Combinatorial auctions, one of the most popular market mechanisms, have a huge effect on electronic markets and political strategies. Combinatorial auctions provide suitable mechanisms for efficient allocation of resources to self-interested attendees. ... Keywords: approximation, combinatorial auction, multi-agent system, optimization, resource allocation

Naoki Fukuta; Takayuki Ito

2009-01-01T23:59:59.000Z

279

Customer Strategies for Responding to Day-Ahead Market HourlyElectricity Pricing  

Science Conference Proceedings (OSTI)

Real-time pricing (RTP) has been advocated as an economically efficient means to send price signals to customers to promote demand response (DR) (Borenstein 2002, Borenstein 2005, Ruff 2002). However, limited information exists that can be used to judge how effectively RTP actually induces DR, particularly in the context of restructured electricity markets. This report describes the second phase of a study of how large, non-residential customers' adapted to default-service day-ahead hourly pricing. The customers are located in upstate New York and served under Niagara Mohawk, A National Grid Company (NMPC)'s SC-3A rate class. The SC-3A tariff is a type of RTP that provides firm, day-ahead notice of hourly varying prices indexed to New York Independent System Operator (NYISO) day-ahead market prices. The study was funded by the California Energy Commission (CEC)'s PIER program through the Demand Response Research Center (DRRC). NMPC's is the first and longest-running default-service RTP tariff implemented in the context of retail competition. The mix of NMPC's large customers exposed to day-ahead hourly prices is roughly 30% industrial, 25% commercial and 45% institutional. They have faced periods of high prices during the study period (2000-2004), thereby providing an opportunity to assess their response to volatile hourly prices. The nature of the SC-3A default service attracted competitive retailers offering a wide array of pricing and hedging options, and customers could also participate in demand response programs implemented by NYISO. The first phase of this study examined SC-3A customers' satisfaction, hedging choices and price response through in-depth customer market research and a Constant Elasticity of Substitution (CES) demand model (Goldman et al. 2004). This second phase was undertaken to answer questions that remained unresolved and to quantify price response to a higher level of granularity. We accomplished these objectives with a second customer survey and interview effort, which resulted in a higher, 76% response rate, and the adoption of the more flexible Generalized Leontief (GL) demand model, which allows us to analyze customer response under a range of conditions (e.g. at different nominal prices) and to determine the distribution of individual customers' response.

Goldman, Chuck; Hopper, Nicole; Bharvirkar, Ranjit; Neenan,Bernie; Boisvert, Dick; Cappers, Peter; Pratt, Donna; Butkins, Kim

2005-08-25T23:59:59.000Z

280

Sub-Hourly Impacts of High Solar Penetrations in the Western United States: Preprint  

DOE Green Energy (OSTI)

This paper presents results of analysis on the sub-hourly impacts of high solar penetrations from the Western Wind and Solar Integration Study Phase 2. Extreme event analysis showed that most large ramps were due to sunrise and sunset events, which have a significant predictability component. Variability in general was much higher in the high-solar versus high-wind scenario. Reserve methodologies that had already been developed for wind were therefore modified to take into account the predictability component of solar variability.

Lew, D.; Brinkman, G.; Ibanez, E.; Hummon, M.; Hodge, B. M.; Heaney, M.; King, J.

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Quantum Calisthenics: Gaussians, The Path Integral and Guided Numerical Approximations  

SciTech Connect

It is apparent to anyone who thinks about it that, to a large degree, the basic concepts of Newtonian physics are quite intuitive, but quantum mechanics is not. My purpose in this talk is to introduce you to a new, much more intuitive way to understand how quantum mechanics works. I begin with an incredibly easy way to derive the time evolution of a Gaussian wave-packet for the case free and harmonic motion without any need to know the eigenstates of the Hamiltonian. This discussion is completely analytic and I will later use it to relate the solution for the behavior of the Gaussian packet to the Feynman path-integral and stationary phase approximation. It will be clear that using the information about the evolution of the Gaussian in this way goes far beyond what the stationary phase approximation tells us. Next, I introduce the concept of the bucket brigade approach to dealing with problems that cannot be handled totally analytically. This approach combines the intuition obtained in the initial discussion, as well as the intuition obtained from the path-integral, with simple numerical tools. My goal is to show that, for any specific process, there is a simple Hilbert space interpretation of the stationary phase approximation. I will then argue that, from the point of view of numerical approximations, the trajectory obtained from my generalization of the stationary phase approximation specifies that subspace of the full Hilbert space that is needed to compute the time evolution of the particular state under the full Hamiltonian. The prescription I will give is totally non-perturbative and we will see, by the grace of Maple animations computed for the case of the anharmonic oscillator Hamiltonian, that this approach allows surprisingly accurate computations to be performed with very little work. I think of this approach to the path-integral as defining what I call a guided numerical approximation scheme. After the discussion of the anharmonic oscillator I will turn to tunneling problems and show that the instanton can also be though of in the same way. I will do this for the classic problem of a double well potential in the extreme limit when the splitting between the two lowest levels is extremely small and the tunneling rate from one well to another is also very small.

Weinstein, Marvin; /SLAC

2009-02-12T23:59:59.000Z

282

projects are valued at approximately $67 million (including $15 million  

NLE Websites -- All DOE Office Websites (Extended Search)

projects are valued at approximately $67 million (including $15 million projects are valued at approximately $67 million (including $15 million in non-Federal cost sharing) over four years. The overall goal of the research is to develop carbon dioxide (CO 2 ) capture and separation technologies that can achieve at least 90 percent CO 2 removal at no more than a 35 percent increase in the cost of electricity. The projects, managed by FE's National Energy Technology Laboratory (NETL), include: (1) Linde, LLC, which will use a post-combustion capture technology incorporating BASF's novel amine-based process at a 1-megawatt electric (MWe) equivalent slipstream pilot plant at the National Carbon Capture Center (NCCC) (DOE contribution: $15 million); (2) Neumann Systems Group, Inc., which will design, construct, and test a patented NeuStreamTM absorber at the Colorado

283

A Multithreaded Algorithm for Network Alignment Via Approximate Matching  

SciTech Connect

Network alignment is an optimization problem to find the best one-to-one map between the vertices of a pair of graphs that overlaps in as many edges as possible. It is a relaxation of the graph isomorphism problem and is closely related to the subgraph isomorphism problem. The best current approaches are entirely heuristic, and are iterative in nature. They generate real-valued heuristic approximations that must be rounded to find integer solutions. This rounding requires solving a bipartite maximum weight matching problem at each step in order to avoid missing high quality solutions. We investigate substituting a parallel, half-approximation for maximum weight matching instead of an exact computation. Our experiments show that the resulting difference in solution quality is negligible. We demonstrate almost a 20-fold speedup using 40 threads on an 8 processor Intel Xeon E7-8870 system (from 10 minutes to 36 seconds).

Khan, Arif; Gleich, David F.; Pothen, Alex; Halappanavar, Mahantesh

2012-11-16T23:59:59.000Z

284

Boussinesq approximation of the Cahn-Hilliard-Navier-Stokes equations  

E-Print Network (OSTI)

We study the interactions between the thermodynamic transition and hydrodynamic flows which would characterise a thermo- and hydro-dynamic evolution of a binary mixture in a dissolution/nucleation process. The primary attention is given to the slow dissolution dynamics. The Cahn-Hilliard approach is used to model the behaviour of evolving and diffusing interfaces. An important peculiarity of the full Cahn-Hilliard-Navier-Stokes equations is the use of the full continuity equation required even for a binary mixture of incompressible liquids, firstly, due to dependence of mixture density on concentration and, secondly, due to strong concentration gradients at liquids' interfaces. Using the multiple-scale method we separate the physical processes occurring on different time scales and, ultimately, provide a strict derivation of the Boussinesq approximation for the Cahn-Hilliard-Navier-Stokes equations. This approximation forms a universal theoretical model that can be further employed for a thermo/hydro-dynamic ...

Vorobev, Anatoliy

2010-01-01T23:59:59.000Z

285

A family of algorithms for approximate Bayesian inference  

E-Print Network (OSTI)

One of the major obstacles to using Bayesian methods for pattern recognition has been its computational expense. This thesis presents an approximation technique that can perform Bayesian inference faster and more accurately than previously possible. This method, "Expectation Propagation," unifies and generalizes two previous techniques: assumeddensity filtering, an extension of the Kalman filter, and loopy belief propagation, an extension of belief propagation in Bayesian networks. The unification shows how both of these algorithms can be viewed as approximating the true posterior distribution with a simpler distribution, which is close in the sense of KL-divergence. Expectation Propagation exploits the best of both algorithms: the generality of assumed-density filtering and the accuracy of loopy belief propagation. Loopy belief propagation, because it propagates exact belief states, is useful for limited types of belief networks, such as purely discrete networks. Expectation Propagati...

Rosalind Picard; Thomas P. Minka; Thomas P Minka

2001-01-01T23:59:59.000Z

286

Product-state Approximations to Quantum Ground States  

E-Print Network (OSTI)

The local Hamiltonian problem consists of estimating the ground-state energy (given by the minimum eigenvalue) of a local quantum Hamiltonian. First, we show the existence of a good product-state approximation for the ground-state energy of 2-local Hamiltonians with one or more of the following properties: (1) high degree, (2) small expansion, or (3) a ground state with sublinear entanglement with respect to some partition into small pieces. The approximation based on degree is a surprising difference between quantum Hamiltonians and classical CSPs (constraint satisfaction problems), since in the classical setting, higher degree is usually associated with harder CSPs. The approximation based on low entanglement, in turn, was previously known only in the regime where the entanglement was close to zero. Since the existence of a low-energy product state can be checked in NP, the result implies that any Hamiltonian used for a quantum PCP theorem should have: (1) constant degree, (2) constant expansion, (3) a "volume law" for entanglement with respect to any partition into small parts. Second, we show that in several cases, good product-state approximations not only exist, but can be found in polynomial time: (1) 2-local Hamiltonians on any planar graph, solving an open problem of Bansal, Bravyi, and Terhal, (2) dense k-local Hamiltonians for any constant k, solving an open problem of Gharibian and Kempe, and (3) 2-local Hamiltonians on graphs with low threshold rank, via a quantum generalization of a recent result of Barak, Raghavendra and Steurer. Our work introduces two new tools which may be of independent interest. First, we prove a new quantum version of the de Finetti theorem which does not require the usual assumption of symmetry. Second, we describe a way to analyze the application of the Lasserre/Parrilo SDP hierarchy to local quantum Hamiltonians.

Fernando G. S. L. Brandão; Aram W. Harrow

2013-09-30T23:59:59.000Z

287

Beyond the Quantum Adiabatic Approximation: Adiabatic Perturbation Theory  

E-Print Network (OSTI)

We introduce a perturbative approach to solving the time dependent Schroedinger equation, named adiabatic perturbation theory (APT), whose zeroth order term is the quantum adiabatic approximation. The small parameter in the power series expansion of the time-dependent wave function is the inverse of the time it takes to drive the system's Hamiltonian from the initial to its final form. We review other standard perturbative and non-perturbative ways of going beyond the adiabatic approximation, extending and finding exact relations among them, and also compare the efficiency of those methods against the APT. Most importantly, we determine APT corrections to the Berry phase by use of the Aharonov-Anandan geometric phase. We then solve several time dependent problems allowing us to illustrate that the APT is the only perturbative method that gives the right corrections to the adiabatic approximation. Finally, we propose an experiment to measure the APT corrections to the Berry phase and show, for a particular spin-1/2 problem, that to first order in APT the geometric phase should be two and a half times the (adiabatic) Berry phase.

Gustavo Rigolin; Gerardo Ortiz; Victor Hugo Ponce

2008-07-09T23:59:59.000Z

288

Local Linear Convergence of Approximate Projections onto Regularized Sets  

E-Print Network (OSTI)

The numerical properties of algorithms for finding the intersection of sets depend to some extent on the regularity of the sets, but even more importantly on the regularity of the intersection. The alternating projection algorithm of von Neumann has been shown to converge locally at a linear rate dependent on the regularity modulus of the intersection. In many applications, however, the sets in question come from inexact measurements that are matched to idealized models. It is unlikely that any such problems in applications will enjoy metrically regular intersection, let alone set intersection. We explore a regularization strategy that generates an intersection with the desired regularity properties. The regularization, however, can lead to a significant increase in computational complexity. In a further refinement, we investigate and prove linear convergence of an approximate alternating projection algorithm. The analysis provides a regularization strategy that fits naturally with many ill-posed inverse problems, and a mathematically sound stopping criterion for extrapolated, approximate algorithms. The theory is demonstrated on the phase retrieval problem with experimental data. The conventional early termination applied in practice to unregularized, consistent problems in diffraction imaging can be justified fully in the framework of this analysis providing, for the first time, proof of convergence of alternating approximate projections for finite dimensional, consistent phase retrieval problems.

D. Russell Luke

2011-08-10T23:59:59.000Z

289

Approximate Controllability for Linear Stochastic Differential Equations in Infinite Dimensions  

SciTech Connect

The objective of the paper is to investigate the approximate controllability property of a linear stochastic control system with values in a separable real Hilbert space. In a first step we prove the existence and uniqueness for the solution of the dual linear backward stochastic differential equation. This equation has the particularity that in addition to an unbounded operator acting on the Y-component of the solution there is still another one acting on the Z-component. With the help of this dual equation we then deduce the duality between approximate controllability and observability. Finally, under the assumption that the unbounded operator acting on the state process of the forward equation is an infinitesimal generator of an exponentially stable semigroup, we show that the generalized Hautus test provides a necessary condition for the approximate controllability. The paper generalizes former results by Buckdahn, Quincampoix and Tessitore (Stochastic Partial Differential Equations and Applications, Series of Lecture Notes in Pure and Appl. Math., vol. 245, pp. 253-260, Chapman and Hall, London, 2006) and Goreac (Applied Analysis and Differential Equations, pp. 153-164, World Scientific, Singapore, 2007) from the finite dimensional to the infinite dimensional case.

Goreac, D. [Universite Paris-Est, LAMA, UMR 8050 (France)], E-mail: dan.goreac@univ-mlv.fr

2009-08-15T23:59:59.000Z

290

Daily/Hourly Hydrosystem Operation : How the Columbia River System Responds to Short-Term Needs.  

SciTech Connect

The System Operation Review, being conducted by the Bonneville Power Administration, the US Army Corps of Engineers, and the US Bureau of Reclamation, is analyzing current and potential future operations of the Columbia River System. One goal of the System Operations Review is to develop a new System Operation Strategy. The strategy will be designed to balance the many regionally and nationally important uses of the Columbia River system. Short-term operations address the dynamics that affect the Northwest hydro system and its multiple uses. Demands for electrical power and natural streamflows change constantly and thus are not precisely predictable. Other uses of the hydro system have constantly changing needs, too, many of which can interfere with other uses. Project operators must address various river needs, physical limitations, weather, and streamflow conditions while maintaining the stability of the electric system and keeping your lights on. It takes staffing around the clock to manage the hour-to-hour changes that occur and the challenges that face project operators all the time.

Columbia River System Operation Review (U.S.)

1994-02-01T23:59:59.000Z

291

NV Energy Large-Scale Photovoltaic Integration Study: Intra-Hour Dispatch and AGC Simulation  

SciTech Connect

The uncertainty and variability with photovoltaic (PV) generation make it very challenging to balance power system generation and load, especially under high penetration cases. Higher reserve requirements and more cycling of conventional generators are generally anticipated for large-scale PV integration. However, whether the existing generation fleet is flexible enough to handle the variations and how well the system can maintain its control performance are difficult to predict. The goal of this project is to develop a software program that can perform intra-hour dispatch and automatic generation control (AGC) simulation, by which the balancing operations of a system can be simulated to answer the questions posed above. The simulator, named Electric System Intra-Hour Operation Simulator (ESIOS), uses the NV Energy southern system as a study case, and models the system’s generator configurations, AGC functions, and operator actions to balance system generation and load. Actual dispatch of AGC generators and control performance under various PV penetration levels can be predicted by running ESIOS. With data about the load, generation, and generator characteristics, ESIOS can perform similar simulations and assess variable generation integration impacts for other systems as well. This report describes the design of the simulator and presents the study results showing the PV impacts on NV Energy real-time operations.

Lu, Shuai; Etingov, Pavel V.; Meng, Da; Guo, Xinxin; Jin, Chunlian; Samaan, Nader A.

2013-01-02T23:59:59.000Z

292

A 25-yr Climatology of Large-Amplitude Hourly Surface Pressure Changes over the Conterminous United States  

Science Conference Proceedings (OSTI)

Hourly surface pressure observations for a 25-yr period (1949–63; 1984–93) for the conterminous United States have been used to map the distribution of large hourly pressure changes defined as falls or rises in excess of 4.25 hPa. Initially, 8431 ...

Lorna L. Koppel; Lance F. Bosart; Daniel Keyser

2000-01-01T23:59:59.000Z

293

Building Technologies Program: Tax Deduction Qualified Software - Hourly Analysis Program (HAP) version 4.31  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1 1 On this page you'll find information about the Hourly Analysis Program (HAP) version 4.31 qualified computer software (www.buildings.energy.gov/qualified_software.html), which calculates energy and power cost savings that meet federal tax incentive requirements for commercial buildings (www.buildings.energy.gov/commercial/). Date Documentation Received by DOE: 17 August 2006 Statements in quotes are from the software developer. Internal Revenue Code §179D (c)(1) and (d) Regulations Notice 2006-52, Section 6 requirements (1) The name, address, and (if applicable) web site of the software developer; Carrier / United Technologies Corporation Carrier Software Systems Bldg TR-4, Room 400A P. O. Box 4808 Syracuse, New York 13221 (2) The name, email address, and

294

Building Technologies Program: Tax Deduction Qualified Software - Hourly Analysis Program (HAP) version 4.34  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

4 4 On this page you'll find information about the Hourly Analysis Program (HAP) version 4.34 qualified computer software (www.buildings.energy.gov/qualified_software.html), which calculates energy and power cost savings that meet federal tax incentive requirements for commercial buildings (www.buildings.energy.gov/commercial/). Date Documentation Received by DOE: 10 August 2007 Statements in quotes are from the software developer. Internal Revenue Code §179D (c)(1) and (d) Regulations Notice 2006-52, Section 6 requirements (1) The name, address, and (if applicable) web site of the software developer; Carrier / United Technologies Corporation Carrier Software Systems Bldg TR-4, Room 400A P. O. Box 4808 Syracuse, New York 13221 (2) The name, email address, and

295

SF 6432-TM Standard Terms and Conditions for Time and Materials Labor Hour Contracts  

NLE Websites -- All DOE Office Websites (Extended Search)

TM (04-95) TM (04-95) Sections II & III SECTION II STANDARD TERMS AND CONDITIONS FOR TIME AND MATERIAL OR LABOR HOURS CONTRACTS INDEX OF CLAUSES THE FOLLOWING CLAUSES APPLY TO THIS CONTRACT AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN THE SIGNATURE PAGE OR SECTION I. No. Title Page "A" Clauses apply to Requests for Quotation and Contracts at any value A10 Definitions 2 A11 Unclassified Contract 2 A12 Assignment 2 *A13 Releases Void 2 *A14 Notice of Labor Disputes 2 *A16 Contractor's Information 2 A17 Delegated Representatives 2 *A18 Defense Priority and Allocation System 2 A19 Terms and Conditions 3 *A20 Permits 3 *A23 Applicable Law 3 *A24 Contractor Records Retention 3 A25 Commerce in Explosives, Firearms and

296

High Temperature Solid-Oxide Electrolyzer 2500 Hour Test Results At The Idaho National Laboratory  

DOE Green Energy (OSTI)

The Idaho National Laboratory (INL) has been developing the concept of using solid oxide fuel cells as electrolyzers for large-scale, high-temperature (efficient), hydrogen production. This program is sponsored by the U.S. Department of Energy under the Nuclear Hydrogen Initiative. Utilizing a fuel cell as an electrolyzer introduces some inherent differences in cell operating conditions. In particular, the performance of fuel cells operated as electrolyzers degrades with time faster. This issue of electrolyzer cell and stack performance degradation over time has been identified as a major barrier to technology development. Consequently, the INL has been working together with Ceramatec, Inc. (Salt Lake City, Utah) to improve the long-term performance of high temperature electrolyzers. As part of this research partnership, the INL conducted a 2500 hour test of a Ceramatec designed and produced stack operated in the electrolysis mode. This paper will provide a summary of experimental results to date for this ongoing test.

Carl Stoots; James O'Brien; Stephen Herring; Keith Condie; Lisa Moore-McAteer; Joseph J. Hartvigsen; Dennis Larsen

2009-11-01T23:59:59.000Z

297

(Project title: E-mc2, A Two-Hour Television Program on NOVA)  

DOE Green Energy (OSTI)

Executive Summary A woman in the early 1700s who became one of Europe’s leading interpreters of mathematics and a poor bookbinder who became one of the giants of nineteenth-century science are just two of the pioneers whose stories NOVA explored in Einstein’s Big Idea. This two-hour documentary premiered on PBS in October 2005 and is based on the best-selling book by David Bodanis, E=mc2: A Biography of the World’s Most Famous Equation. The film and book chronicle the scientific challenges and discoveries leading up to Einstein’s startling conclusion that mass and energy are one, related by the formula E = mc2.

Susanne Simpson

2007-05-07T23:59:59.000Z

298

2500-Hour High Temperature Solid-Oxide Electrolyzer Long Duration Test  

DOE Green Energy (OSTI)

The Idaho National Laboratory (INL) has been developing the concept of using solid oxide fuel cells as electrolyzers for large-scale, high-temperature (efficient), hydrogen production. This program is sponsored by the U.S. Department of Energy under the Nuclear Hydrogen Initiative. Utilizing a fuel cell as an electrolyzer introduces some inherent differences in cell operating conditions. In particular, the performance of fuel cells operated as electrolyzers degrades with time faster. This issue of electrolyzer cell and stack performance degradation over time has been identified as a major barrier to technology development. Consequently, the INL has been working together with Ceramatec, Inc. (Salt Lake City, Utah) to improve the long-term performance of high temperature electrolyzers. As part of this research partnership, the INL conducted a 2500 hour test of a Ceramatec designed and produced stack operated in the electrolysis mode. This report will provide a summary of experimental results for this long duration test.

C. M. Stoots; J. E. O'Brien; K. G. Condie; L. Moore-McAteer; J. J. Hartvigsen; D. Larsen

2009-11-01T23:59:59.000Z

299

Approximating RR Lyrae light curves using cubic polynomials  

E-Print Network (OSTI)

In this paper, we use cubic polynomials to approximate RR Lyrae light curves and apply the method to HST data of RR Lyraes in the halo of M31. We compare our method to the standard method of Fourier decomposition and find that the method of cubic polynomials eliminates virtually all ringing effects and does so with significantly fewer parameters than the Fourier technique. Further, for RRc stars the parameters in the fit are all physical. Our study also reveals a number of additional periodicites in this data not found previously: we find 23 RRc stars, 29 RRab stars and 3 multiperiodic stars.

Reyner, Steven; Ngeow, C; Morgan, C

2010-01-01T23:59:59.000Z

300

Analytical Approximation for 2-D Nonlinear Periodic Deep Water Waves  

E-Print Network (OSTI)

A recently developed method has been extended to a nonlocal equation arising in steady water wave propagation in two dimensions. We obtain analyic approximation of steady water wave solution in two dimensions with rigorous error bounds for a set of parameter values that correspond to heights slightly smaller than the critical. The wave shapes are shown to be analytic. The method presented in quite general and does not assume smallness of wave height or steepness and can be readily extended to other interfacial problems involving Laplace's equation.

Saleh Tanveer

2013-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

152 CULLETIN OF THE UNITED STATES FISH COMMISSION. of wine pour one-half gill warm vinegar over the pieces of carp before  

E-Print Network (OSTI)

. Make a filling of four ounces tallow or fre& fat pork, four ydks of eggA, some wheat bread slightly

302

5-Axis Freeform Surface Milling using Piecewise Ruled Surface Approximation  

E-Print Network (OSTI)

This paper presents a 5-axis side milling scheme for freeform surfaces based on automatic piecewise ruled surface approximation. With this scheme, resulting surface finish is accurate and pleasing, and has a smaller scallop height compared to ball-end milling. The ruled surface approximation can be made arbitrarily precise resulting in an overall fast milling operation that satisfies tight tolerances, and smoother surface finish. The class of surfaces that can take advantage of this type of 5-axis milling operation includes both convex and saddle-like (hyperbolic) shapes. 1 Introduction The automatic toolpath generation for manufacturing of models consisting of freeform surfaces is a difficult problem addressed by numerous researchers [Bob85, Choi89, Choi93, Chou89, Elb93, Elb94, Fers86, Jera91, Lone87, Sait91, Spen90, Zhan86]. 3-axis machining [Bob85, Choi89, Fers86, Jera91, Lone87, Sait91, Spen90, Zhan86] is more frequently used than 4- or 5-axis machining modes. While deri...

Gershon Elber; Russ Fish

2000-01-01T23:59:59.000Z

303

Asymptotic analysis of multiscale approximations to reaction networks  

E-Print Network (OSTI)

A reaction network is a chemical system involving multiple reactions and chemical species. Stochastic models of such networks treat the system as a continuous time Markov chain on the number of molecules of each species with reactions as possible transitions of the chain. In many cases of biological interest some of the chemical species in the network are present in much greater abundance than others and reaction rate constants can vary over several orders of magnitude. We consider approaches to approximation of such models that take the multiscale nature of the system into account. Our primary example is a model of a cell’s viral infection for which we apply a combination of averaging and law of large number arguments to show that the “slow ” component of the model can be approximated by a deterministic equation and to characterize the asymptotic distribution of the “fast ” components. The main goal is to illustrate techniques that can be used to reduce the dimensionality of much more complex models. 1. Stochastic models for reaction networks. A reaction network is a chemical system involving multiple reactions and chemical species. The simplest stochastic model for a network treats the system as a continuous time Markov chain whose state X is a vector giving the number of molecules of each species present with each reaction modeled as a possible transition for the state. The model for the kth reaction is determined by a vector of inputs ?k specifying the number of molecules of each chemical species that are

Karen Ball; Thomas G. Kurtz; Lea Popovic; Greg Rempala

1961-01-01T23:59:59.000Z

304

Complexity and approximability of certain bicriteria location problems  

SciTech Connect

We investigate the complexity and approximability of some location problems when two distance values are specified for each pair of potential sites. These problems involve the selection of a specified number of facilities (i.e. a placement of a specified size) to minimize a function of one distance metric subject to a budget constraint on the other distance metric. Such problems arise in several application areas including statistical clustering, pattern recognition and load-balancing in distributed systems. We show that, in general, obtaining placements that are near-optimal with respect to the first distance metric is NP-hard even when we allow the budget constraint on the second distance metric to be violated by a constant factor. However, when both the distance metrics satisfy the triangle inequality, we present approximation algorithms that produce placements which are near-optimal with respect to the first distance metric while violating the budget constraint only by a small constant factor. We also present polynomial algorithms for these problems when the underlying graph is a tree.

Krumke, S.O.; Noltemeier, H. [Wuerzburg Univ. (Germany); Ravi, S.S. [State Univ. of New York, Albany, NY (United States); Marathe, M.V. [Los Alamos National Lab., NM (United States)

1995-10-01T23:59:59.000Z

305

Nonadiabatic charged spherical evolution in the postquasistatic approximation  

Science Conference Proceedings (OSTI)

We apply the postquasistatic approximation, an iterative method for the evolution of self-gravitating spheres of matter, to study the evolution of dissipative and electrically charged distributions in general relativity. The numerical implementation of our approach leads to a solver which is globally second-order convergent. We evolve nonadiabatic distributions assuming an equation of state that accounts for the anisotropy induced by the electric charge. Dissipation is described by streaming-out or diffusion approximations. We match the interior solution, in noncomoving coordinates, with the Vaidya-Reissner-Nordstroem exterior solution. Two models are considered: (i) a Schwarzschild-like shell in the diffusion limit; and (ii) a Schwarzschild-like interior in the free-streaming limit. These toy models tell us something about the nature of the dissipative and electrically charged collapse. Diffusion stabilizes the gravitational collapse producing a spherical shell whose contraction is halted in a short characteristic hydrodynamic time. The streaming-out radiation provides a more efficient mechanism for emission of energy, redistributing the electric charge on the whole sphere, while the distribution collapses indefinitely with a longer hydrodynamic time scale.

Rosales, L. [Laboratorio de Fisica Computacional, Universidad Experimental Politecnica 'Antonio Jose de Sucre', Puerto Ordaz (Venezuela, Bolivarian Republic of); Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Peralta, C. [Deutscher Wetterdienst, Frankfurter Str. 135, 63067 Offenbach (Germany); School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Rodriguez-Mueller, B. [Computational Science Research Center, College of Sciences, San Diego State University, San Diego, California (United States)

2010-10-15T23:59:59.000Z

306

Approximate Weighted Matching On Emerging Manycore and Multithreaded Architectures  

SciTech Connect

Graph matching is a prototypical combinatorial problem with many applications in computer science and scientific computing, but algorithms for computing optimal matchings are challenging to parallelize. Approximate matching algorithms provide an alternate route for parallelization, and in many contexts compute near-optimal matchings for large-scale graphs. We present sharedmemory parallel implementations for computing half-approximate weighted matching on state-of-the-art multicore (Intel Nehalem and AMD Magny-Cours), manycore (Nvidia Tesla and Nvidia Fermi) and massively multithreaded (Cray XMT) platforms. We provide two implementations: the first implementation uses shared work queues, and is suited to all these platforms; the second implementation is based on dataflow principles, and exploits the architectural features of the Cray XMT. Using a carefully chosen dataset that exhibits characteristics from a wide range of real-world applications, we show scalable performance across different platforms. In particular, for one instance of the input, an R-MAT graph (RMAT-G), we show speedups of: about 32 on 48 cores of an AMD Magny-Cours; 7 on 8 cores of Intel Nehalem; 3 on Nvidia Tesla and 10 on Nvidia Fermi relative to one core of Intel Nehalem; and 60 on 128 processors of Cray XMT. We demonstrate good weak and strong scaling for graphs with up to a billion edges using up to 12, 800 threads. Given the breadth of this work, we focus on simplicity and portability of software rather than excessive fine-tuning for each platform. To the best of our knowledge, this is the first such large-scale study of the half-approximate weighted matching problem on shared-memory platforms. Driven by the critical enabling role of combinatorial algorithms such as matching in scientific computing and the emergence of informatics applications, there is a growing demand to support irregular computations on current and future computing platforms. In this context, we evaluate the capability of emerging multithreaded platforms to tolerate latency induced by irregular memory access patterns, and to support fine-grained parallelism via light-weight synchronization mechanisms. By contrasting the architectural features of these platforms against the Cray XMT, which is specifically designed to support irregular memory-intensive applications, we delineate the impact of these choices on performance.

Halappanavar, Mahantesh; Feo, John T.; Villa, Oreste; Tumeo, Antonino; Pothen, Alex

2012-11-30T23:59:59.000Z

307

Finite temperature electronic simulations beyond the Born-Oppenheimer approximation  

E-Print Network (OSTI)

We introduce a general technique to compute finite temperature electronic properties by a novel covariant formulation of the electronic partition function. By using a rigorous variational upper bound to the free energy we are led to the evaluation of a partition function that can be computed stochastically by sampling electronic wave functions and atomic positions (assumed classical). In order to achieve this target we show that it is extremely important to consider the non trivial geometry of the space defined by the wave function ansatz. The method can be extended to any technique capable to provide an energy value over a given wave function ansatz depending on several variational parameters and atomic positions. In particular we can take into account electronic correlation, by using the standard variational quantum Monte Carlo method, that has been so far limited to zero temperature ground state properties. We show that our approximation reduces correctly to the standard Born-Oppenheimer (BO) one at zero t...

Mazzola, Guglielmo; Sorella, Sandro

2013-01-01T23:59:59.000Z

308

Pion - Nucleon Bremsstrahlung beyond the Soft-Photon approximation  

E-Print Network (OSTI)

A dynamical model based on effective Lagrangians is proposed to describe the bremsstrahlung reaction $ \\pi N \\to \\pi N \\gamma$ at low energies. The $\\Delta(1232)$ degrees of freedom are incorporated in a way consistent with both, electromagnetic gauge invariance and invariance under contact transformations. The model also includes the initial and final state rescattering of hadrons via a T-matrix with off the momentum-shell effects. The double differential distribution of photons is computed for three different T-matrix models and the results are compared with the soft photon approximation, and with experimental data. The aim of this analysis is to test the off-shell behaviour of the different T-matrices under consideration. Finally an alternative simpler dynamical model that incorporates the unstable character of the isobar-$\\Delta(1232)$ through a complex mass, is presented. As we will see it is suitable for the study of the magnetic moment of the resonance.

A. Mariano

2000-04-06T23:59:59.000Z

309

Improved first order mean spherical approximation for simple fluids  

E-Print Network (OSTI)

A perturbation approach based on the first-order mean spherical approximation (FMSA) is proposed. It consists in adopting a hard-sphere plus short-range attractive Yukawa fluid as the novel reference system, over which the perturbative solution of the Ornstein-Zernike equation is performed. A choice of the optimal range of the reference attraction is discussed. The results are compared against conventional FMSA/HS theory and Monte-Carlo simulation data for compressibility factor and vapor-liquid phase diagrams of the medium-ranged Yukawa fluid. Proposed theory keeps the same level of simplicity and transparency, as the conventional FMSA/HS approach does, but shows to be more accurate.

S. Hlushak; A. Trokhymchuk; I. Nezbeda

2012-02-20T23:59:59.000Z

310

COSMOLOGICAL POST-NEWTONIAN APPROXIMATION COMPARED WITH PERTURBATION THEORY  

Science Conference Proceedings (OSTI)

We compare the cosmological first-order post-Newtonian (1PN) approximation with the relativistic cosmological linear perturbation theory in a zero-pressure medium with the cosmological constant. We compare equations and solutions in several different gauge conditions available in both methods. In the PN method we have perturbation equations for density, velocity, and gravitational potential independently of the gauge condition to 1PN order. However, correspondences with these 1PN equations are available only in certain gauge conditions in the perturbation theory. Equations of perturbed velocity and the perturbed gravitational potential in the zero-shear gauge exactly coincide with the Newtonian equations, which remain valid even to 1PN order (the same is true for perturbed velocity identified in the comoving gauge), and equations of perturbed density in the zero-shear gauge and the uniform-expansion gauge coincide to 1PN order. We identify other correspondences available in different gauge conditions of the perturbation theory.

Noh, Hyerim [Korea Astronomy and Space Science Institute, Daejon 305-348 (Korea, Republic of); Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

2012-10-01T23:59:59.000Z

311

Meteorological Patterns Associated with Maximum 3-Hour Average Concentrations Predicted by the CRSTER Model for a Tall Stack Source  

Science Conference Proceedings (OSTI)

Regional meteorological patterns associated with maximum 3-hour average concentrations predicted by the U.S. EPA CRSTER model for emissions from a tall stack were examined for a limited sample. Causes of predicted peaks were the movements of weak ...

Paul N. Derezotes

1984-11-01T23:59:59.000Z

312

ANALYTIC APPROXIMATION OF CARBON CONDENSATION ISSUES IN TYPE II SUPERNOVAE  

SciTech Connect

I present analytic approximations for some issues related to condensation of graphite, TiC, and silicon carbide in oxygen-rich cores of supernovae of Type II. Increased understanding, which mathematical analysis can support, renders researchers more receptive to condensation in O-rich supernova gases. Taking SN 1987A as typical, my first analysis shows why the abundance of CO molecules reaches an early maximum in which free carbon remains more abundant than CO. This analysis clarifies why O-rich gas cannot oxidize C if {sup 56}Co radioactivity is as strong as in SN 1987A. My next analysis shows that the CO abundance could be regarded as being in chemical equilibrium if the CO molecule is given an effective binding energy rather than its laboratory dissociation energy. The effective binding energy makes the thermal dissociation rate of CO equal to its radioactive dissociation rate. This preserves possible relevance for the concept of chemical equilibrium. My next analysis shows that the observed abundances of CO and SiO molecules in SN 1987A rule out frequent suggestions that equilibrium condensation of SUNOCONs has occurred following atomic mixing of the He-burning shell with more central zones in such a way as to reproduce roughly the observed spectrum of isotopes in SUNOCONs while preserving C/O > 1. He atoms admixed along with the excess carbon would destroy CO and SiO molecules, leaving their observed abundances unexplained. The final analysis argues that a chemical quasiequilibrium among grains (but not gas) may exist approximately during condensation, so that its computational use is partially justified as a guide to which mineral phases would be stable against reactions with gas. I illustrate this point with quasiequilibrium calculations by Ebel and Grossman that have shown that graphite is stable even when O/C >1 if prominent molecules are justifiably excluded from the calculation of chemical equilibrium.

Clayton, Donald D., E-mail: claydonald@gmail.com [Department of Physics and Astronomy, Clemson University, Clemson, SC (United States)

2013-01-01T23:59:59.000Z

313

Wind Power Plants and System Operation in the Hourly Time Domain: Preprint  

DOE Green Energy (OSTI)

Because wind is an intermittent power source, the variability may have significant impacts on system operation. Part of the difficulty of analyzing the load following impact of wind is the inadequacy of most modeling frameworks to accurately treat wind plants and the difficulty of untangling causal impacts of wind plants from other dynamic phenomena. This paper presents a simple analysis of an hourly load-following requirement that can be performed without extensive computer modeling. The approach is therefore useful as a first step to quantifying these impacts when extensive modeling and data sets are not available. The variability that wind plants add to the electricity supply must be analyzed in the context of overall system variability. The approach used in this paper does just that. The results show that wind plants do have an impact on load following, but when calculated as a percentage of the installed wind plant capacity, this impact is not large. Another issue is the extent to which wind forecast errors add to imbalance. The relative statistical independence of wind forecast errors and load forecast errors can be used to help quantify the extent to which wind forecast errors impact overall system imbalances.

Milligan, M.

2003-05-01T23:59:59.000Z

314

After-hours Power Status of Office Equipment in the USA  

SciTech Connect

Office equipment is expected to be the fastest-growingsegment of commercial energy use over the next 20 years, yet many aspectsof office equipment energy use are poorly understood. User behavior, suchas turning off devices at night or enabling power management, influencesenergy use to a great extent. The computing environment also plays a roleboth in influencing user behavior and in the success of power management.Information about turn-off rates and power management rates for officeequipment was collected through a series of after-hours audits incommercial buildings. Sixteen businesses were recruited, includingoffices (small, medium and large offices in a variety of industries),schools, and medical buildings in California, Georgia, and Pennsylvania.The types and power states of office equipment found in these buildingswere recorded and analyzed. This article presents these data forcomputers, monitors, printers, copiers, fax machines, scanners andmulti-function devices. These data can be used to improve estimates ofboth energy consumption for these devices and savings from energyconservation efforts.

Webber, Carrie A.; Roberson, Judy A.; McWhinney, Marla C.; Brown,Richard E.; Pinckard, Margaret J.; Busch, John F.

2005-10-13T23:59:59.000Z

315

After-hours Power Status of Office Equipment and Inventory of Miscellaneous Plug-load Equipment  

Science Conference Proceedings (OSTI)

This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the after-hours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of ''miscellaneous'' plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers. This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings. The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential. This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from twelve commercial buildings in California, Georgia, and Pennsylvania: two health care buildings, two large offices (> 500 employees each), three medium offices (50-500 employees), four education buildings, and one ''small office'' that is actually an aggregate of five small businesses. Two buildings are in the San Francisco Bay area of California, five are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.

Roberson, Judy A.; Webber, Carrie A.; McWhinney, Marla C.; Brown, Richard E.; Pinckard, Margaret J.; Busch, John F.

2004-01-22T23:59:59.000Z

316

Predicting Future Hourly Residential Electrical Consumption: A Machine Learning Case Study  

Science Conference Proceedings (OSTI)

Whole building input models for energy simulation programs are frequently created in order to evaluate specific energy savings potentials. They are also often utilized to maximize cost-effective retrofits for existing buildings as well as to estimate the impact of policy changes toward meeting energy savings goals. Traditional energy modeling suffers from several factors, including the large number of inputs required to characterize the building, the specificity required to accurately model building materials and components, simplifying assumptions made by underlying simulation algorithms, and the gap between the as-designed and as-built building. Prior works have attempted to mitigate these concerns by using sensor-based machine learning approaches to model energy consumption. However, a majority of these prior works focus only on commercial buildings. The works that focus on modeling residential buildings primarily predict monthly electrical consumption, while commercial models predict hourly consumption. This means there is not a clear indicator of which techniques best model residential consumption, since these methods are only evaluated using low-resolution data. We address this issue by testing seven different machine learning algorithms on a unique residential data set, which contains 140 different sensors measurements, collected every 15 minutes. In addition, we validate each learner's correctness on the ASHRAE Great Energy Prediction Shootout, using the original competition metrics. Our validation results confirm existing conclusions that Neural Network-based methods perform best on commercial buildings. However, the results from testing our residential data set show that Feed Forward Neural Networks, Support Vector Regression (SVR), and Linear Regression methods perform poorly, and that Hierarchical Mixture of Experts (HME) with Least Squares Support Vector Machines (LS-SVM) performs best - a technique not previously applied to this domain.

Edwards, Richard E [ORNL; New, Joshua Ryan [ORNL; Parker, Lynne Edwards [ORNL

2012-01-01T23:59:59.000Z

317

A Sublogarithmic Approximation for Highway and Tollbooth Pricing  

E-Print Network (OSTI)

An instance of the tollbooth problem consists of an undirected network and a collection of single-minded customers, each of which is interested in purchasing a fixed path subject to an individual budget constraint. The objective is to assign a per-unit price to each edge in a way that maximizes the collective revenue obtained from all customers. The revenue generated by any customer is equal to the overall price of the edges in her desired path, when this cost falls within her budget; otherwise, that customer will not purchase any edge. Our main result is a deterministic algorithm for the tollbooth problem on trees whose approximation ratio is O(log m / log log m), where m denotes the number of edges in the underlying graph. This finding improves on the currently best performance guarantees for trees, due to Elbassioni et al. (SAGT '09), as well as for paths (commonly known as the highway problem), due to Balcan and Blum (EC '06). An additional interesting consequence is a computational separation between tol...

Gamzu, Iftah

2010-01-01T23:59:59.000Z

318

The Framework for Approximate Queries on Simulation Data  

SciTech Connect

AQSim is a system intended to enable scientists to query and analyze a large volume of scientific simulation data. The system uses the state of the art in approximate query processing techniques to build a novel framework for progressive data analysis. These techniques are used to define a multi-resolution index, where each node contains multiple models of the data. The benefits of these models are two-fold: (1) they are compact representations, reconstructing only the information relevant to the analysis, and (2) the variety of models capture different aspects of the data which may be of interest to the user but are not readily apparent in their raw form. To be able to deal with the data interactively, AQSim allows the scientist to make an informed tradeoff between query response accuracy and time. In this paper, we present the framework of AQSim with a focus on its architectural design. We also show the results from an initial proof-of-concept prototype developed at LLNL. The presented framework is generic enough to handle more than just simulation data.

Abdulla, G; Baldwin, C; Critchlow, T; Kamimura, R; Lee, B; Musick, R; Snapp, R; Tang, N

2001-09-27T23:59:59.000Z

319

Evolution of primordial magnetic fields in mean-field approximation  

E-Print Network (OSTI)

We study the evolution of phase-transition-generated cosmic magnetic fields coupled to the primeval cosmic plasma in turbulent and viscous free-streaming regimes. The evolution laws for the magnetic energy density and correlation length, both in helical and non-helical cases, are found by solving the autoinduction and Navier-Stokes equations in mean-field approximation. Analytical results are derived in Minkowski spacetime and then extended to the case of a Friedmann universe with zero spatial curvature, both in radiation and matter dominated eras. The three possible viscous free-streaming phases are characterized by a drag term in the Navier-Stokes equation which depends on the free-steaming properties of neutrinos, photons, or hydrogen atoms, respectively. In the case of non-helical magnetic fields, the magnetic intensity $B$ and the magnetic correlation length $\\xi_B$ evolve asymptotically with the temperature $T$ as $B(T) \\simeq \\kappa_B (N_i v_i)^{\\varrho_1} (T/T_i)^{\\varrho_2}$ and $\\xi_B(T) \\simeq \\kap...

Campanelli, Leonardo

2013-01-01T23:59:59.000Z

320

2008. Approximating learning curves for active-learning-driven annotation  

E-Print Network (OSTI)

Active learning (AL) is getting more and more popular as a methodology to considerably reduce the annotation effort when building training material for statistical learning methods for various NLP tasks. A crucial issue rarely addressed, however, is when to actually stop the annotation process to profit from the savings in efforts. This question is tightly related to estimating the classifier performance after a certain amount of data has already been annotated. While learning curves are the default means to monitor the progress of the annotation process in terms of classifier performance, this requires a labeled gold standard which – in realistic annotation settings, at least – is often unavailable. We here propose a method for committee-based AL to approximate the progression of the learning curve based on the disagreement among the committee members. This method relies on a separate, unlabeled corpus and is thus well suited for situations where a labeled gold standard is not available or would be too expensive to obtain. Considering named entity recognition as a test case we provide empirical evidence that this approach works well under simulation as well as under real-world annotation conditions. 1.

Katrin Tomanek; Udo Hahn

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Controlled Nonlinear Stochastic Delay Equations: Part I: Modeling and Approximations  

SciTech Connect

This two-part paper deals with 'foundational' issues that have not been previously considered in the modeling and numerical optimization of nonlinear stochastic delay systems. There are new classes of models, such as those with nonlinear functions of several controls (such as products), each with is own delay, controlled random Poisson measure driving terms, admissions control with delayed retrials, and others. There are two basic and interconnected themes for these models. The first, dealt with in this part, concerns the definition of admissible control. The classical definition of an admissible control as a nonanticipative relaxed control is inadequate for these models and needs to be extended. This is needed for the convergence proofs of numerical approximations for optimal controls as well as to have a well-defined model. It is shown that the new classes of admissible controls do not enlarge the range of the value functions, is closed (together with the associated paths) under weak convergence, and is approximatable by ordinary controls. The second theme, dealt with in Part II, concerns transportation equation representations, and their role in the development of numerical algorithms with much reduced memory and computational requirements.

Kushner, Harold J., E-mail: hjk@dam.brown.edu [Brown University, Applied Math (United States)

2012-08-15T23:59:59.000Z

322

Asymptotic safety in the f(R) approximation  

E-Print Network (OSTI)

In the asymptotic safety programme for quantum gravity, it is important to go beyond polynomial truncations. Three such approximations have been derived where the restriction is only to a general function f(R) of the curvature R>0. We confront these with the requirement that a fixed point solution be smooth and exist for all non-negative R. Singularities induced by cutoff choices force the earlier versions to have no such solutions. However, we show that the most recent version has a number of lines of fixed points, each supporting a continuous spectrum of eigen-perturbations. We uncover and analyse the first five such lines. Sensible fixed point behaviour may be achieved if one consistently incorporates geometry/topology change. As an exploratory example, we analyse the equations analytically continued to R<0, however we now find only partial solutions.We show how these results are always consistent with, and to some extent can be predicted from, a straightforward analysis of the constraints inherent in the equations.

Juergen A. Dietz; Tim R. Morris

2012-11-05T23:59:59.000Z

323

A Hierarchy of Approximations of the Master Equation Scaled by a Size Parameter  

Science Conference Proceedings (OSTI)

Solutions of the master equation are approximated using a hierarchy of models based on the solution of ordinary differential equations: the macroscopic equations, the linear noise approximation and the moment equations. The advantage with the approximations ... Keywords: Linear noise approximation, Master equation, Moment equations, Reaction rate equations

Lars Ferm; Per Lötstedt; Andreas Hellander

2008-02-01T23:59:59.000Z

324

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

SciTech Connect

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.

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

1997-05-01T23:59:59.000Z

325

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

SciTech Connect

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.

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

1998-03-01T23:59:59.000Z

326

Instructor's Name Email Address Office Hours Allen, Chris christopherallen@pdx.edu W 3:00-4:00pm CH 366  

E-Print Network (OSTI)

Instructor's Name Email Address Office Hours Office Location Allen, Chris christopherallen CH 361 Fall 2011 Instructor Office Hours #12;Pickett-Cooper, Patty pickettp@pdx.edu F 11:30-1:30pm CH

327

[14] DIRECT TRANSFER ELECTROPHORESIS 187 which usually takes less than an hour. The database should be monitored  

E-Print Network (OSTI)

[14] DIRECT TRANSFER ELECTROPHORESIS 187 which usually takes less than an hour. The database should MemorialScholarship, and M.S.C. by AppliedBiosystems. [14] DNA Sequencing with Direct Transfer are preparative electrophoresis methods and direct transfer electro- phoresis. ~°In direct transfer

Church, George M.

328

Energy savings can be communicated in terms of kilowatt hours (energy), carbon (climate change) or pounds (cost).  

E-Print Network (OSTI)

AIM Energy savings can be communicated in terms of kilowatt hours (energy), carbon (climate change for saving energy and impact subsequent perceptions and behaviour. A particular focus here is behaviour beyond immediate energy consumption behaviour, i.e., more general environmental behaviours. SOCIAL VALUES

McAuley, Derek

329

Evaluation of Cold-Season Precipitation Forecasts Generated by the Hourly Updating High-Resolution Rapid Refresh Model  

Science Conference Proceedings (OSTI)

The hourly updating High-Resolution Rapid Refresh (HRRR) model is evaluated with regard to its ability to predict the areal extent of cold-season precipitation and accurately depict the timing and location of regions of snow, rain, and mixed-phase ...

Kyoko Ikeda; Matthias Steiner; James Pinto; Curtis Alexander

2013-08-01T23:59:59.000Z

330

Comparison of Daily Averaged Reflection, Transmission, and Absorption for Selected Radiative Flux Transfer Approximations  

Science Conference Proceedings (OSTI)

This paper compares accuracy for the daily averaged reflection, transmission, and absorption of solar flux derived from the delta-four-stream approximation and a few selected two-stream approximations. In the chosen variety of two-stream ...

Xun Zhu; Albert Arking

1994-12-01T23:59:59.000Z

331

Numerical Approximations Can Create Chaos-related Errors in Blocking Forecasts  

Science Conference Proceedings (OSTI)

The chaotic structure of two-dimensional atmospheric flow is illustrated. It is shown that certain errors in numerical approximations can Prevent the correct prediction of chaotic processes. This is the case when the numerical approximations do ...

Juhani Rinne; Heikki Järvinen

1992-05-01T23:59:59.000Z

332

CLUSTER-VARIATION METHOD FOR THE TRIANGULAR LATTICE GAS II. TRIANGLE APPROXIMATION  

E-Print Network (OSTI)

with the zero~field lattice gas can be identified IsingFOR THE TRIANGULAR LATTICE GAS II. TRIANGLE APPROXIMATION R.method for the triangular lattice gas Triangle approximation

Osorio, R.

2013-01-01T23:59:59.000Z

333

An improved procedure for developing a calibrated hourly simulation model of an electrically heated and cooled commercial building  

E-Print Network (OSTI)

With the increased use of building energy simulation programs, calibration of simulated data to measured data has been recognized as an important factor in substantiating how well the model fits a real building. Model calibration to measured monthly utility data has been utilized for many years. Recently, efforts have reported calibrated models at the hourly level. Most of the previous methods have relied on very simple comparisons including bar charts, monthly percent difference time-series graphs, and x-y scatter plots. A few advanced methods have been proposed as well which include carpet plots and comparative 3-D time-series plots. Unfortunately, at hourly levels of calibration, many of the traditional graphical calibration techniques become overwhelmed with data and suffer from data overlap. In order to improve upon previously established techniques, this thesis presents new calibration methods including temperature binned box-whisker-mean analysis to improve x-y scatter plots, 24-hour weather-daytype box-whisker-mean graphs to show hourly temperature-dependent energy use profiles, and 52-week box-whisker-mean plots to display long-term trends. In addition to the graphical calibration techniques, other methods are also used including indoor temperature calibration to improve thermostat schedules and architectural rendering as a means of verifying the building envelope dimensions and shading placement. Several statistical methods are also reviewed for their appropriateness including percent difference, mean bias error (MBE), and the coefficient of variation of the root mean squared error. Results are presented using a case study building located in Washington, D.C. In the case study building, nine months of hourly whole-building electricity data and site-specific weather data were measured and used with the DOE-2. 1D building simulation program to test the new techniques. Use of the new calibration procedures were able to produce a MBE of-0.7% and a CV(RMSE) of 23. 1 % which compare favorably with the most accurate hourly neural network models.

Bou-Saada, Tarek Edmond

1994-01-01T23:59:59.000Z

334

Handbook of solar energy data for south-facing surfaces in the United States. Volume II. Average hourly and total daily insolation data for 235 localities (Alaska - Montana)  

DOE Green Energy (OSTI)

Average hourly and daily total insolaion estimates are given for 235 US sites at a variety of array tilt angles. (MHR)

Smith, J.H.

1980-01-15T23:59:59.000Z

335

A Study on How the Electricity Market as a Whole and Consumers in Particular Could Benefit if More Consumers were to buy Electricity on Hourly Metering.  

E-Print Network (OSTI)

?? When consumers are able to buy electricity on an hourly instead of monthly basis, the demand side flexibility is likely to increase. One way… (more)

Lundström, Fredrik

2010-01-01T23:59:59.000Z

336

Extension of the weak-line approximation and application to correlated-k methods  

Science Conference Proceedings (OSTI)

Global climate models require accurate and rapid computation of the radiative transfer through the atmosphere. Correlated-k methods are often used. One of the approximations used in correlated-k models is the weakline approximation. We introduce an approximation T/sub g/ which reduces to the weak-line limit when optical depths are small, and captures the deviation from the weak-line limit as the extinction deviates from the weak-line limit. This approximation is constructed to match the first two moments of the gamma distribution to the k-distribution of the transmission. We compare the errors of the weak-line approximation with T/sub g/ in the context of a water vapor spectrum. The extension T/sub g/ is more accurate and converges more rapidly than the weak-line approximation.

Conley, A.J.; Collins, W.D.

2011-03-15T23:59:59.000Z

337

Table A6. Approximate Heat Rates for Electricity, and Heat Content ...  

U.S. Energy Information Administration (EIA)

State energy information, detailed and overviews. Maps. ... Table A6. Approximate Heat Rates for Electricity, and Heat Content of Electricity, 1949-2011

338

OpenEI - hourly  

Open Energy Info (EERE)

are given by a location defined by the Typical Meteorological Year (TMY) for which the weather data was collected. Commercial load data is sorted by the (TMY) site as a...

339

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to {approximately}178 dpa at {approximately}400{degrees}C  

Science Conference Proceedings (OSTI)

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and {approximately}400{degrees}C, the irradiation creep of 20% cold-worked PCA has become dominated by the {open_quotes}creep disappearance{close_quotes} phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from {approximately}20 to {approximately}40%.

Toloczko, M.B. [Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering; Garner, F.A. [Pacific Northwest Lab., Richland, WA (United States)

1993-09-01T23:59:59.000Z

340

PDSF Office Hours 9/5/13 from 2:00 to 4:00 pm at LBNL  

NLE Websites -- All DOE Office Websites (Extended Search)

9/5/13 from 9/5/13 from 2:00 to 4:00 pm at LBNL PDSF Office Hours 9/5/13 from 2:00 to 4:00 pm at LBNL September 5, 2013 (0 Comments) I have biweekly office hours on Thursdays at LBNL. The next one is Thursday 9/5/13 from 2:00 - 4:00 pm in the NERSC drop in office at 050A-0143A (in the basement by the bus offices). Please feel free to stop by if you have any questions or want some hands on help with PDSF issues. Post your comment You cannot post comments until you have logged in. Login Here. Comments No one has commented on this page yet. RSS feed for comments on this page | RSS feed for all comments User Announcements Email announcement archive Subscribe via RSS Subscribe Browse by Date November 2013 October 2013 September 2013 August 2013 March 2012 February 2012 January 2012

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Observed Temperature Effects on Hourly Residential Electric LoadReduction in Response to an Experimental Critical Peak PricingTariff  

SciTech Connect

The goal of this investigation was to characterize themanual and automated response of residential customers to high-price"critical" events dispatched under critical peak pricing tariffs testedin the 2003-2004 California Statewide Pricing Pilot. The 15-monthexperimental tariff gave customers a discounted two-price time-of-userate on 430 days in exchange for 27 critical days, during which the peakperiod price (2 p.m. to 7 p.m.) was increased to about three times thenormal time-of-use peak price. We calculated response by five-degreetemperature bins as the difference between peak usage on normal andcritical weekdays. Results indicatedthat manual response to criticalperiods reached -0.23 kW per home (-13 percent) in hot weather(95-104.9oF), -0.03 kW per home (-4 percent) in mild weather (60-94.9oF),and -0.07 kW per home (-9 percent) during cold weather (50-59.9oF).Separately, we analyzed response enhanced by programmable communicatingthermostats in high-use homes with air-conditioning. Between 90oF and94.9oF, the response of this group reached -0.56 kW per home (-25percent) for five-hour critical periods and -0.89 kW/home (-41 percent)for two-hour critical periods.

Herter, Karen B.; McAuliffe, Patrick K.; Rosenfeld, Arthur H.

2005-11-14T23:59:59.000Z

342

PDSF Office Hours 10/17/13 from 2:00 to 4:00 pm at LBNL  

NLE Websites -- All DOE Office Websites (Extended Search)

10/17/13 from 10/17/13 from 2:00 to 4:00 pm at LBNL PDSF Office Hours 10/17/13 from 2:00 to 4:00 pm at LBNL October 7, 2013 (0 Comments) I have biweekly office hours on Thursdays at LBNL. The next one is Thursday 10/17/13 from 2:00 - 4:00 pm in the NERSC drop in office at 050A-0143A (in the basement by the bus offices). Please feel free to stop by if you have any questions or want some hands on help with PDSF issues. Post your comment You cannot post comments until you have logged in. Login Here. Comments No one has commented on this page yet. RSS feed for comments on this page | RSS feed for all comments User Announcements Email announcement archive Subscribe via RSS Subscribe Browse by Date November 2013 October 2013 September 2013 August 2013 March 2012 February 2012 January 2012

343

Low complexity channel models for approximating flat Rayleigh fading in network simulations  

E-Print Network (OSTI)

The intricate dependency of networking protocols upon the performance of the wireless channel motivates the investigation of network channel approximations for fading channels. Wireless networking protocols are increasingly being designed and evaluated with the assistance of networking simulators. While evaluating networking protocols such as medium access control, routing, and reliable transport, the network channel model, and its associated capacity, will drastically impact the achievable network throughput. Researcher relying upon simulation results must therefore use extreme caution to ensure the use of similar channel models when performing protocol comparisons. Some channel approximations have been created to mimic the behavior of a fading environment, however there exists little to no justification for these channel approximations. This dissertation addresses the need for a computationally efficient fading channel approximation for use in network simulations. A rigorous flat fading channel model was developed for use in accuracy measurements of channel approximations. The popular two-state Markov model channel approximation is analyzed and shown to perform poorly for low to moderate signal-to-noise ratios (SNR). Three novel channel approximations are derived, with multiple methods of parameter estimation. Each model is analyzed for both statistical performance and network performance. The final model is shown to achieve very accurate network throughput performance by achieving a very close matching of the frame run distributions. This work provides a rigorous evaluation of the popular two-state Markov model, and three novel low complexity channel models in both statistical accuracy and network throughput performance. The novel models are formed through attempts to match key statistical parameters of frame error run and good frame run statistics. It is shown that only matching key parameters is insufficient to achieve an acceptable channel approximation and that it is necessary to approximate the distribution of frame error duration and good frame run duration. The final novel channel approximation, the three-state run-length model, is shown to achieve a good approximation of the desired distributions when some key statistical parameters are matched.

McDougall, Jeffrey Michael

2003-08-01T23:59:59.000Z

344

An accurate approximation to the average error probability of cooperative diversity in Nakagami-m fading  

Science Conference Proceedings (OSTI)

A new approximation to the average symbol error rate of cooperative diversity is derived for independent and non-identically distributed Nakagami-m fading channels. The new approximation has the same computational complexity as previous lower bounds ... Keywords: Nakagami, cooperative diversity, fading channels, symbol error rate

Norman C. Beaulieu; Yunfei Chen

2010-09-01T23:59:59.000Z

345

On spectral approximation of static and dynamical problems for elastic multistructures  

Science Conference Proceedings (OSTI)

The present paper is devoted to the construction and investigation of algorithms of spectral approximation of three-dimensional problems for nonhomogeneous anisotropic elastic multistructures in curvilinear coordinates, which are junctions of three-dimensional ... Keywords: elastic multistructures, error bounds, spectral approximation

Gia Avalishvili; Mariam Avalishvili

2009-06-01T23:59:59.000Z

346

Optimal approximations for risk measures of sums of lognormals based on conditional expectations  

Science Conference Proceedings (OSTI)

In this paper we investigate the approximations for the distribution function of a sum S of lognormal random variables. These approximations are obtained by considering the conditional expectation E[S|@L] of S with respect to a conditioning random variable ... Keywords: Comonotonicity, Conditional expectation, Jensen's inequality, Lognormal, Maximal variance

S. Vanduffel; X. Chen; J. Dhaene; M. Goovaerts; L. Henrard; R. Kaas

2008-11-01T23:59:59.000Z

347

Shock-compressible-vortex interactions: Computing approximate post-shock fields  

E-Print Network (OSTI)

Shock-compressible-vortex interactions: Computing approximate post-shock fields G.K. O'Reilly and D of the passage of a planar shock through a steady compressible vortex is developed. To compute the approximate post-shock fields, the steady pre-shock vortex is decomposed into a sum of frozen sinusoidal modes

Barr, Al

348

Certified Approximation of Parametric Space Curves with Cubic B-spline Curves  

E-Print Network (OSTI)

Approximating complex curves with simple parametric curves is widely used in CAGD, CG, and CNC. This paper presents an algorithm to compute a certified approximation to a given parametric space curve with cubic B-spline curves. By certified, we mean that the approximation can approximate the given curve to any given precision and preserve the geometric features of the given curve such as the topology, singular points, etc. The approximated curve is divided into segments called quasi-cubic B\\'{e}zier curve segments which have properties similar to a cubic rational B\\'{e}zier curve. And the approximate curve is naturally constructed as the associated cubic rational B\\'{e}zier curve of the control tetrahedron of a quasi-cubic curve. A novel optimization method is proposed to select proper weights in the cubic rational B\\'{e}zier curve to approximate the given curve. The error of the approximation is controlled by the size of its tetrahedron, which converges to zero by subdividing the curve segments. As an applic...

Shen, Liyong; Gao, Xiao-Shan

2012-01-01T23:59:59.000Z

349

A scaling approximation for structure factors in the integral equation theory of polydisperse nonionic colloidal fluids  

E-Print Network (OSTI)

Integral equation of pure liquids, combined with a new "scaling approximation" based on a corresponding states treatment of pair correlation functions, is used to evaluate approximate structure factors for colloidal fluids constituted of uncharged particles with polydispersity in size and energy parameters. Both hard spheres and Lennard-Jones interactions are considered. For polydisperse hard spheres, the scaling approximation is compared to theories utilized by small angle scattering experimentalists (decoupling approximation, local monodisperse approximation)and to the van der Waals one-fluid theory. The results are tested against predictions from analytical expressions, exact within the Percus-Yevick approximation. For polydisperse Lennard-Jones particles, the scaling approximation combined with a "modified hypernetted chain" integral equation, is tested against molecular dynamics data generated for the present work. Despite ist simplicity, the scaling approximation exhibits a satisfactory performance for both potentials and represents a considerable improvement over the above mentioned theories. Shortcomings of the proposed theory, its applicability to the analysis of experimental scattering data, and its possible extensions to different potentials are finally discussed.

Domenico Gazzillo; Achille Giacometti; Raffaele G. Della Valle; Elisabetta Venuti; Flavio Carsughi

1999-07-23T23:59:59.000Z

350

Hardness of approximation and integer programming frameworks for searching for caterpillar trees  

Science Conference Proceedings (OSTI)

We consider the problems of finding a caterpillar tree in a graph. We first prove that, unless P=NP, there is no approximation algorithms for finding a minimum spanning caterpillar in a graph within a factor of f(n); where f(n) ... Keywords: approximation algorithm, caterpillar trees, integer programming, optimization, semidefinite programming

Micheal J. Dinneen, Masoud Khosravani

2011-01-01T23:59:59.000Z

351

Approximate deconvolution large eddy simulation of a barotropic ocean circulation model  

E-Print Network (OSTI)

This paper puts forth a new large eddy simulation closure modeling strategy for two-dimensional turbulent geophysical flows. This closure modeling approach utilizes approximate deconvolution, which is based solely on mathematical approximations and does not employ phenomenological arguments, such as the concept of an energy cascade. The new approximate deconvolution model is tested in the numerical simulation of the wind-driven circulation in a shallow ocean basin, a standard prototype of more realistic ocean dynamics. The model employs the barotropic vorticity equation driven by a symmetric double-gyre wind forcing, which yields a four-gyre circulation in the time mean. The approximate deconvolution model yields the correct four-gyre circulation structure predicted by a direct numerical simulation, on a much coarser mesh but at a fraction of the computational cost. This first step in the numerical assessment of the new model shows that approximate deconvolution could represent a viable alternative to standar...

San, Omer; Wang, Zhu; Iliescu, Traian

2011-01-01T23:59:59.000Z

352

Approximate treatment of electron Coulomb distortion in quasielastic (e,e') reactions  

E-Print Network (OSTI)

In this paper we address the adequacy of various approximate methods of including Coulomb distortion effects in (e,e') reactions by comparing to an exact treatment using Dirac-Coulomb distorted waves. In particular, we examine approximate methods and analyses of (e,e') reactions developed by Traini et al. using a high energy approximation of the distorted waves and phase shifts due to Lenz and Rosenfelder. This approximation has been used in the separation of longitudinal and transverse structure functions in a number of (e,e') experiments including the newly published 208Pb(e,e') data from Saclay. We find that the assumptions used by Traini and others are not valid for typical (e,e') experiments on medium and heavy nuclei, and hence the extracted structure functions based on this formalism are not reliable. We describe an improved approximation which is also based on the high energy approximation of Lenz and Rosenfelder and the analyses of Knoll and compare our results to the Saclay data. At each step of our analyses we compare our approximate results to the exact distorted wave results and can therefore quantify the errors made by our approximations. We find that for light nuclei, we can get an excellent treatment of Coulomb distortion effects on (e,e') reactions just by using a good approximation to the distorted waves, but for medium and heavy nuclei simple additional ad hoc factors need to be included. We describe an explicit procedure for using our approximate analyses to extract so-called longitudinal and transverse structure functions from (e,e') reactions in the quasielastic region.

K. S. Kim; L. E. Wright; Yanhe Jin; D. W. Kosik

2005-03-30T23:59:59.000Z

353

The distribution of cloud cover over the former USSR as derived from the RIHMI 223-Station 3-hourly meteorological database  

SciTech Connect

In recent years a great deal of meteorological and climatological data has been exchanged between the two principal climate data centers of the United States and the former Soviet Union: the National Climatic Data Center (NCDC), in Asheville, North Carolina, and the Research Institute of Hydrometeorological Information (RIHMI) in Obninsk, Russia. This was accomplished via Working Group VIB (Influence of Environmental Changes on Climate) of the bilateral initiative known as the Agreement on Protection of the Environment, established on May 23, 1972 by the United States and the USSR. One of the key datasets compiled by RIHMI includes 3-hourly meteorological observations from 223 USSR stations for the period 1966-83. RIHMI has chosen to use daily and hourly data from these stations as the basis for considerable climate research efforts. These data (hereafter referred to as the RIHMI database) will soon be made available by both NCDC and the Department of Energy`s Carbon Dioxide Information Analysis Center (CDIAC) in Oak Ridge, Tennessee. The data have undergone extensive quality assurance checks at RIHMI, NCDC, and CDIAC. The data contain observations of some 22 meteorological variables, including near-surface air temperature, sea level pressure, precipitation amount, weather type, and total cloud cover. This study uses the RIHMI database to examine the spatial distribution of total cloud cover over the former USSR (hereafter referred to as the USSR). In this initial assessment, we focus on comparing our results with total cloud cover data presented in the atlas: Global Distribution of Total Cloud Cover and Cloud Type Amounts Over Land for the common data period 1971-81.

Kaiser, D.P.; Vose, R.S. [Oak Ridge National Lab., TN (United States); Karl, T.R. [National Climatic Data Center, Asheville, NC (United States); Razuvaev, V.N. [Research Institute of Hydrometeorological Information, Obninsk (Russian Federation)

1995-02-01T23:59:59.000Z

354

Optimal Constant-Time Approximation Algorithms and (Unconditional) Inapproximability Results for Every Bounded-Degree CSP  

E-Print Network (OSTI)

Raghavendra (STOC 2008) gave an elegant and surprising result: if Khot's Unique Games Conjecture (STOC 2002) is true, then for every constraint satisfaction problem (CSP), the best approximation ratio is attained by a certain simple semidefinite programming and a rounding scheme for it. In this paper, we show that a similar result holds for constant-time approximation algorithms in the bounded-degree model. Specifically, we present the followings: (i) For every CSP, we construct an oracle that serves an access, in constant time, to a nearly optimal solution of a basic LP relaxation of the CSP. (ii) Using the oracle, we present a constant-time rounding scheme that achieves an approximation ratio coincident with the integrality gap of the basic LP. (iii) We give a generic conversion from integrality gaps of basic LPs to hardness results. All of those results are ``unconditional.'' Therefore, for every bounded-degree CSP, we give the best constant-time approximation algorithm among all.

Yoshida, Yuichi

2010-01-01T23:59:59.000Z

355

Longwave 3D Benchmarks for Inhomogeneous Clouds and Comparisons with Approximate Methods  

Science Conference Proceedings (OSTI)

The purpose of this study is twofold: to (i) establish three-dimensional (3D) longwave radiative transfer benchmarks for inhomogeneous cloud fields and (ii) compare the results with three approximate, 1D methods. The benchmark results are ...

George P. Kablick III; Robert G. Ellingson; Ezra E. Takara; Jlujing Gu

2011-04-01T23:59:59.000Z

356

Approximation fixpoint theory and the semantics of logic and answers set programs  

Science Conference Proceedings (OSTI)

Approximation Fixpoint Theory was developed as a fixpoint theory of lattice operators that provides a uniform formalization of four main semantics of three major nonmonotonic reasoning formalisms. This paper clarifies how this fixpoint theory can define ...

Marc Denecker; Maurice Bruynooghe; Joost Vennekens

2012-01-01T23:59:59.000Z

357

EA-1915: Conveyance of Approximately 1,641 Acres of Unimproved Land to the  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

5: Conveyance of Approximately 1,641 Acres of Unimproved Land 5: Conveyance of Approximately 1,641 Acres of Unimproved Land to the Tri-City Development Council, the Local Community Reuse Organization, Richland, WA EA-1915: Conveyance of Approximately 1,641 Acres of Unimproved Land to the Tri-City Development Council, the Local Community Reuse Organization, Richland, WA Summary This EA will evaluate the environmental impacts of conveyance of approximately 1,641 acres of unimproved land at DOE's Hanford Site, Richland, Washington to the Tri-City Development Council, the local community reuse organization. Public Comment Opportunities None available at this time. Documents Available for Download September 19, 2012 EA-1915: Notice of Intent to Prepare an Environmental Assessment and Notice of Potential Floodplain and Wetland Involvement

358

Approximate analysis of the temperature induced stresses and deformations of composite shells  

Science Conference Proceedings (OSTI)

In this paper simple formulas are presented which can be used to estimate the response of composite plates and shells to hygrothermal loads. The layup of the shell can be arbitrary (i.e., it can be symmetric or unsymmetric, balanced or unbalanced). The formulas serve two purposes. First, they can be used to calculate directly the stresses, strains, and displacements caused by a temperature and a moisture gradient. Second, the formulas can be used to determine the 'effective' thermal and moisture expansion coefficients which are the parameters needed in more accurate numerical (FEM) calculations. The accuracies of the approximate formulas were assessed by sample problems. In these problems the hygrothermal deformations of cylinders and cylindrical segments were calculated by the present approximate formulas and by an exact, three-dimensional analysis. The results of the exact and approximate methods were compared. These comparisons showed that the approximate formulas yield the deformations with a high degree of accuracy. 18 refs.

Kollar, L.P. (Stanford Univ., Stanford, CA (United States))

1994-01-01T23:59:59.000Z

359

Approximating game-theoretic optimal strategies for full-scale poker  

Science Conference Proceedings (OSTI)

The computation of the first complete approximations of game-theoretic optimal strategies for full-scale poker is addressed. Several abstraction techniques are combined to represent the game of 2-player Texas Hold'em, having size O(1018), ...

D. Billings; N. Burch; A. Davidson; R. Holte; J. Schaeffer; T. Schauenberg; D. Szafron

2003-08-01T23:59:59.000Z

360

Analytic Approximation of Discrete Field Samples with Weighted Sums and the Gridless Computation of Field Derivatives  

Science Conference Proceedings (OSTI)

Objective analysis by weighted sums of discrete observations is equivalent to the approximation of the distribution of an observed parameter by a function which is also analytic, provided that the weighting function is both analytic and positive ...

F. Caracena

1987-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Base-state Substitution: An Idealized Modeling Technique for Approximating Environmental Variability  

Science Conference Proceedings (OSTI)

Base-state substitution (BSS) is a novel modeling technique for approximating environmental heterogeneity in idealized simulations. After a certain amount of model run time, base-state substitution replaces the original horizontally homogeneous ...

Casey E. Letkewicz; Adam J. French; Matthew D. Parker

362

Bounds and Approximations for Sums of Dependent Log-Elliptical Random Variables  

E-Print Network (OSTI)

Dhaene, Denuit, Goovaerts, Kaas & Vyncke (2002a,b) have studied convex bounds for a sum of dependent random variables and applied these to sums of log-normal random variables. In particular, they have shown how these convex bounds can be used to derive closed-form approximations for several of the risk measures of such a sum. In this paper we investigate to which extent their general results on convex bounds can also be applied to sums of log-elliptical random variables which incorporate sums of log-normals as a special case. Firstly, we show that unlike the log-normal case, for general sums of log-ellipticals the convex lower bound does no longer result in closed form approximations for the different risk measures. Secondly, we demonstrate how instead the weaker stop-loss order can be used to derive such closed form approximations. We also present numerical examples to show the accuracy of the proposed approximations.

unknown authors

2008-01-01T23:59:59.000Z

363

Modified Delta-Eddington Approximation for Solar Reflection, Transmission, and Absorption Calculations  

Science Conference Proceedings (OSTI)

The fractional factor f of ?-function scaling in the ?-Eddington approximation modifies the fractional scattering into the forward peak. As shown in this paper, reasonably choosing the factor f can yield a great improvement of transmission, ...

Jinhuan Qiu

1999-08-01T23:59:59.000Z

364

A New Approximate Solution of the Optimal Nonlinear Filter for Data Assimilation in Meteorology and Oceanography  

Science Conference Proceedings (OSTI)

This paper introduces a new approximate solution of the optimal nonlinear filter suitable for nonlinear oceanic and atmospheric data assimilation problems. The method is based on a local linearization in a low-rank kernel representation of the ...

I. Hoteit; D-T. Pham; G. Triantafyllou; G. Korres

2008-01-01T23:59:59.000Z

365

Medial Spheres for Shape Approximation Svetlana Stolpner, Paul Kry, Kaleem Siddiqi  

E-Print Network (OSTI)

distance tests than the state-of-the-art method for sphere set approximation for the class of (, )-fat-of-detail rendering [4], shape matching [5], and shape deformation [6]. In the above applications, it is desirable

Dudek, Gregory

366

Monotone Finite-Difference Approximations to the Advection-Condensation Problem  

Science Conference Proceedings (OSTI)

We discuss herein numerical difficulties with finite-difference approximations to the thermodynamic conservation laws near sharp, cloud-environment interfaces. The Conservation laws for entropy and water substance variables are coupled through ...

Wojciech W. Grabowski; Piotr K. Smolarkiewicz

1990-10-01T23:59:59.000Z

367

A Comparison of Ekman Pumping in Approximate Models of the Accelerating Planetary Boundary Layer  

Science Conference Proceedings (OSTI)

Several theories of the planetary boundary layer that retain the flow accelerations in approximate form are compared. Two special test cases focus on the role of either local or convective accelerations. The semigeotriptic theory of Cullen ...

Peter R. Bannon

1998-04-01T23:59:59.000Z

368

Base-State Substitution: An Idealized Modeling Technique for Approximating Environmental Variability  

Science Conference Proceedings (OSTI)

Base-state substitution (BSS) is a novel modeling technique for approximating environmental heterogeneity in idealized simulations. After a certain amount of model run time, base-state substitution replaces the original horizontally homogeneous ...

Casey E. Letkewicz; Adam J. French; Matthew D. Parker

2013-09-01T23:59:59.000Z

369

Four-Stream Spherical Harmonic Expansion Approximation for Solar Radiative Transfer  

Science Conference Proceedings (OSTI)

This paper presents a four-stream extension of the ?-Eddington approximation by considering the higher-order spherical harmonic expansion in radiative intensity. By using the orthogonality relation of the spherical harmonic functions, the ...

J. Li; V. Ramaswamy

1996-04-01T23:59:59.000Z

370

Effects of the Boussinesq Approximation on the Results of Strongly-Buoyant Plume Calculations  

Science Conference Proceedings (OSTI)

Nearly all mathematical models which are commonly used to predict the dispersion of chimney gases in the atmosphere or heated water discharges in the aquatic environment employ the so-called Boussinesq approximation. It is part of this ...

M. Schatzmann; A. J. Policastro

1984-01-01T23:59:59.000Z

371

A Coupled Atmosphere–Ocean Radiative Transfer System Using the Analytic Four-Stream Approximation  

Science Conference Proceedings (OSTI)

A coupled atmosphere–ocean radiative transfer model based on the analytic four-stream approximation has been developed. It is shown that this radiation model is computationally efficient and at the same time can achieve acceptable accuracy for ...

Wei-Liang Lee; K. N. Liou

2007-10-01T23:59:59.000Z

372

An Approximation to Multiple Scattering in the Earth's Atmosphere: Almucantar Radiance Formulation  

Science Conference Proceedings (OSTI)

The retrieval of aerosol size distributions from solar aureole measurements, in the past, have been made tractable by assuming the single-scattering approximation, since the inclusion of multiple scattering by solving the complete radiative ...

M. A. Box; A. Deepak

1981-05-01T23:59:59.000Z

373

Table A6. Approximate Heat Rates for Electricity, and Heat Content ...  

U.S. Energy Information Administration (EIA)

Total Fossil Fuels 6,7: ... 7 The fossil-fuels heat rate is used as the thermal conversion factor for ... approximate the quantity of fossil fuels replaced by these ...

374

A Simple Model of a Convectively Coupled Walker Circulation Using the Weak Temperature Gradient Approximation  

Science Conference Proceedings (OSTI)

An idealized model of a Walker circulation based on the weak temperature gradient (WTG) approximation and a single baroclinic vertical mode for all fields is analyzed. The circulation is forced by a sinusoidal variation of sea surface temperature ...

Christopher S. Bretherton; Adam H. Sobel

2002-10-01T23:59:59.000Z

375

Approximate consensus in the dynamic stochastic network with incomplete information and measurement delays  

Science Conference Proceedings (OSTI)

Consideration was given to the problem of achieving an approximate consensus in the decentralized stochastic dynamic network under incomplete information about the current states of the nodes, measurement delay, and variable structure of links. Solution ...

N. O. Amelina; A. L. Fradkov

2012-11-01T23:59:59.000Z

376

Few body impulse and fixed scatterer approximations for high energy scattering  

E-Print Network (OSTI)

The elastic scattering differential cross section is calculated for proton scattering from $^6$He at 717 MeV, using single scattering terms of the multiple scattering expansion of the total transition amplitude (MST). We analyse the effects of different scattering frameworks, specifically the Factorized Impulse Approximation (FIA) and the Fixed Scatterer (adiabatic) Approximation (FSA) and the uncertainties associated with the use different structure models.

R. Crespo; A. M. Moro; I. J. Thompson

2006-03-02T23:59:59.000Z

377

Estimating the Bias of Local Polynomial Approximations Using the Peano Kernel  

SciTech Connect

These presentation visuals define local polynomial approximations, give formulas for bias and random components of the error, and express bias error in terms of the Peano kernel. They further derive constants that give figures of merit, and show the figures of merit for 3 common weighting functions. The Peano kernel theorem yields estimates for the bias error for local-polynomial-approximation smoothing that are superior in several ways to the error estimates in the current literature.

Blair, J., and Machorro, E.

2012-03-22T23:59:59.000Z

378

Development of iteration strategies for a practical implementation of a higher order transverse leakage approximation  

Science Conference Proceedings (OSTI)

Transverse integrated nodal diffusion methods currently represent the standard in full core neutronic simulation. The primary shortcoming in this approach is the utilization of the quadratic transverse leakage approximation. This approach, although proven to work well for typical LWR problems, is not consistent with the formulation of nodal methods and can cause accuracy and convergence problems. In previous work, an improved, consistent quadratic leakage approximation was formulated, which derived from the class of higher order nodal methods developed some years ago. In this paper a number of iteration schemes are developed around this consistent quadratic leakage approximation which yield accurate node average results in much improved calculational times. The developed consistent leakage approximation is extended in this work via a number of numerical schemes, the most promising of which results from utilizing the consistent leakage approximation as a correction method to the standard quadratic leakage approximation. Numerical results are demonstrated on a set of benchmark problems, such as the 3D IAEA LWR and MOX C5 problems. (authors)

Prinsloo, R. H.; Tomasevic, D. I. [Necsa, PO Box 582, Pretoria, 0001 (South Africa)

2012-07-01T23:59:59.000Z

379

Forecasting Techniques The Use of Hourly Model-Generated Soundings to Forecast Mesoscale Phenomena. Part I: Initial Assessment in Forecasting Warm-Season Phenomena  

Science Conference Proceedings (OSTI)

Since late 1995, NCEP has made available to forecasters hourly model guidance at selected sites in the form of vertical profiles of various forecast fields. These profiles provide forecasters with increased temporal resolution and greater ...

Robert E. Hart; Gregory S. Forbes; Richard H. Grumm

1998-12-01T23:59:59.000Z

380

Noise kernel for a quantum field in Schwarzschild spacetime under the Gaussian approximation  

E-Print Network (OSTI)

A method is given to compute an approximation to the noise kernel, defined as the symmetrized connected 2-point function of the stress tensor, for the conformally invariant scalar field in any spacetime conformal to an ultra-static spacetime for the case in which the field is in a thermal state at an arbitrary temperature. The most useful applications of the method are flat space where the approximation is exact and Schwarzschild spacetime where the approximation is better than it is in most other spacetimes. The two points are assumed to be separated in a timelike or spacelike direction. The method involves the use of a Gaussian approximation which is of the same type as that used by Page to compute an approximate form of the stress tensor for this field in Schwarzschild spacetime. All components of the noise kernel have been computed exactly for hot flat space and one component is explicitly displayed. Several components have also been computed for Schwarzschild spacetime and again one component is explicitly displayed.

A. Eftekharzadeh; Jason D. Bates; Albert Roura; Paul R. Anderson; B. L. Hu

2010-11-22T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Exact and approximate solutions for the quantum minimum-Kullback-entropy estimation problem  

E-Print Network (OSTI)

The minimum Kullback entropy principle (mKE) is a useful tool to estimate quantum states and operations from incomplete data and prior information. In general, the solution of a mKE problem is analytically challenging and an approximate solution has been proposed and employed in different context. Recently, the form and a way to compute the exact solution for finite dimensional systems has been found, and a question naturally arises on whether the approximate solution could be an effective substitute for the exact solution, and in which regimes this substitution can be performed. Here, we provide a systematic comparison between the exact and the approximate mKE solutions for a qubit system when average data from a single observable are available. We address both mKE estimation of states and weak Hamiltonians, and compare the two solutions in terms of state fidelity and operator distance. We find that the approximate solution is generally close to the exact one unless the initial state is near an eigenstate of the measured observable. Our results provide a rigorous justification for the use of the approximate solution whenever the above condition does not occur, and extend its range of application beyond those situations satisfying the assumptions used for its derivation.

Carlo Sparaciari; Stefano Olivares; Francesco Ticozzi; Matteo G. A. Paris

2013-11-23T23:59:59.000Z

382

The Complexity of Approximating Bounded-Degree Boolean #CSP (Extended Abstract)  

E-Print Network (OSTI)

The degree of a CSP instance is the maximum number of times that a variable may appear in the scope of constraints. We consider the approximate counting problem for Boolean CSPs with bounded-degree instances, for constraint languages containing the two unary constant relations {0} and {1}. When the maximum degree is at least 25 we obtain a complete classification of the complexity of this problem. It is exactly solvable in polynomial-time if every relation in the constraint language is affine. It is equivalent to the problem of approximately counting independent sets in bipartite graphs if every relation can be expressed as conjunctions of {0}, {1} and binary implication. Otherwise, there is no FPRAS unless NP=RP. For lower degree bounds, additional cases arise in which the complexity is related to the complexity of approximately counting independent sets in hypergraphs.

Dyer, Martin E; Jalsenius, Markus; Richerby, David

2010-01-01T23:59:59.000Z

383

Tests of Monte Carlo Independent Column Approximation in the ECHAM5  

NLE Websites -- All DOE Office Websites (Extended Search)

Tests of Monte Carlo Independent Column Approximation in the ECHAM5 Tests of Monte Carlo Independent Column Approximation in the ECHAM5 Atmospheric GCM Raisanen, Petri Finnish Meteoroligical Institute Jarvenoja, Simo Finnish Meteorological Institute Jarvinen, Heikki Finnish Meteorological Institute Category: Modeling The Monte Carlo Independent Column Approximation (McICA) was recently introduced as a new approach for parametrizing broadband radiative fluxes in global climate models (GCMs). The McICA allows a flexible description of unresolved cloud structure, and it is unbiased with respect to the full ICA, but its results contain conditional random errors (i.e., noise). In this work, McICA and a stochastic cloud generator have been implemented to the Max Planck Institute for Meteorology's ECHAM5 atmospheric GCM. The

384

DOE Seeks to Invest Approximately $1.3 Billion to Commercialize CCS  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Invest Approximately $1.3 Billion to Commercialize CCS to Invest Approximately $1.3 Billion to Commercialize CCS Technology DOE Seeks to Invest Approximately $1.3 Billion to Commercialize CCS Technology June 24, 2008 - 2:15pm Addthis Funding Opportunity Announcement Solicits Applications for Restructured FutureGen Program WASHINGTON, DC - The U.S. Department of Energy (DOE) today issued a Funding Opportunity Announcement (FOA) to invest in multiple commercial-scale Integrated Gasification Combined Cycle (IGCC) or other clean coal power plants with cutting-edge carbon capture and storage (CCS) technology under the Department's restructured FutureGen program. The solicitation is seeking multiple cost-shared projects to advance coal-based power generation technologies that capture and store the greenhouse gas carbon

385

Controlled Nonlinear Stochastic Delay Equations: Part II: Approximations and Pipe-Flow Representations  

SciTech Connect

This is the second part of a work dealing with key issues that have not been addressed in the modeling and numerical optimization of nonlinear stochastic delay systems. We consider new classes of models, such as those with nonlinear functions of several controls (such as products), each with is own delay, controlled random Poisson measure driving terms, admissions control with delayed retrials, and others. Part I was concerned with issues concerning the class of admissible controls and their approximations, since the classical definitions are inadequate for our models. This part is concerned with transportation equation representations and their approximations. Such representations of nonlinear stochastic delay models have been crucial in the development of numerical algorithms with much reduced memory and computational requirements. The representations for the new models are not obvious and are developed. They also provide a template for the adaptation of the Markov chain approximation numerical methods.

Kushner, Harold J., E-mail: hjk@dam.brown.edu [Brown University, Applied Math (United States)

2012-08-15T23:59:59.000Z

386

Stabilizing control of parallel AC-DC power transmission systems by approximate switching curve  

SciTech Connect

A method to improve the transient stability of bulk power transmission system is presented. The method stabilizes the control of parallel ac-dc transmission systems using an approximate switching curve. The optimal switching curve is approximated by a power series and the resulting switching curve is determined independent of type and duration of faults that occur to the system. In addition, coefficients of the switching curve can be calculated on a off-line basis which allows use of simple on-line algebraic calculations in emergency conditions.

Ichiyanagi, K.; Kobayashi, H.; Kakehu, H.

1980-01-01T23:59:59.000Z

387

Scalar O(N) Model at Finite Temperature -- 2PI Effective Potential in Different Approximations  

E-Print Network (OSTI)

We calculate the two-particle irreducible (2PI) effective potential of the O(N) linear sigma model in 1+1 dimensions. The approximations we use are the next-to-leading order of a 1/N expansion (for arbitrary N) and a kind of "resummed loop approximation" for N=1. We show that the effective potential of the 1/N expansion is convex for N=4 and N=10 whereas it is not for the "loop" expansion and the case N=1 of the 1/N expansion.

Jurgen Baacke; Stefan Michalski

2004-09-14T23:59:59.000Z

388

High performance steam cogeneration (proof-of-concept phases). Phase 2, HRSG 500-hour test report: Final report  

SciTech Connect

Recent advances in small once-through Alloy 800 steam generators, improved materials technology, and application of small industrial gas turbine technology to steam turbine cogeneration offers the potential to make a step increase in steam temperature from around 1000{degree}F, where industry has been for almost fifty years, to 1500{degree}F. In small cogeneration systems, it is economically practical to introduce new technology and make a step change in temperature where it may not be possible (given the regulatory environment and economic risk) for a major change in steam temperature to be introduced in the hundreds of megawatt size of an electric utility. Increasing the peak steam temperature in a steam turbine cycle allows more work to be extracted or electrical power to be generated from a given quantity of heat input. Figure 1 plots steam efficiency as a function of superheat steam temperature and pressure for a turbine-back pressure of 166 psia. This figure clearly shows that increasing the steam conditions from the typical current practice of 900{degree}F and 900 psia to 1500{degree}F and 1500 psia will increase the steam cycle efficiency by 53%. The combination of higher cycle efficiency with an advanced high efficiency steam turbine design provides a substantial increase in turbine output power for a given steam flowrate. The output of this advanced high temperature steam turbine is approximately twice that of a current industrial practive turbine for the same turbine flowrate as seen in Figure 2.

Campbell, A.H.

1992-12-01T23:59:59.000Z

389

After-hours power status of office equipment and energy use of miscellaneous plug-load equipment  

Science Conference Proceedings (OSTI)

This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the after-hours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of miscellaneous plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers. For most types of miscellaneous equipment, we also estimated typical unit energy consumption in order to estimate total energy consumption of the miscellaneous devices within our sample. This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings. The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential. This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from sixteen commercial buildings in California, Georgia, and Pennsylvania: four education buildings, two medical buildings, two large offices (> 500 employees each), three medium offices (50-500 employees each), and five small business offices (< 50 employees each). Two buildings are in the San Francisco Bay are a of California, nine (including the five small businesses) are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.

Roberson, Judy A.; Webber, Carrie A.; McWhinney, Marla C.; Brown, Richard E.; Pinckard, Marageret J.; Busch, John F.

2004-05-27T23:59:59.000Z

390

Buffer sizing for minimum energy-delay product by using an approximating polynomial  

Science Conference Proceedings (OSTI)

This paper first presents an accurate and efficient method of estimating the short circuit energy dissipation and the output transition time of CMOS buffers. Next, the paper describes a sizing method for tapered buffer chains. It is shown that the first-order ... Keywords: buffer sizing, polynomial approximation, short circuit energy

Chang Woo Kang; Soroush Abbaspour; Massoud Pedram

2003-04-01T23:59:59.000Z

391

Use of symbolic and numeric methods in an algorithm for the approximation of multivariate functions  

Science Conference Proceedings (OSTI)

In this paper, we discuss aspects of a particular algorithm, namely that of finding an approximation to a real function of n variables, that uses both symbolic and numeric manipulations. Development of this algorithm was motivated in part by an actual ...

David K. Kahaner; Mark B. Wells

1976-08-01T23:59:59.000Z

392

Approximate k-NN delta test minimization method using genetic algorithms: Application to time series  

Science Conference Proceedings (OSTI)

In many real world problems, the existence of irrelevant input variables (features) hinders the predictive quality of the models used to estimate the output variables. In particular, time series prediction often involves building large regressors of ... Keywords: Approximate k-nearest neighbors, Delta test, Genetic algorithm, Time series, Variable projection, Variable scaling, Variable selection

Fernando Mateo; Dušan Sovilj; Rafael Gadea

2010-06-01T23:59:59.000Z

393

The estimates of approximation by using a new type of weighted modulus of continuity  

Science Conference Proceedings (OSTI)

In this paper, we introduce a new type modulus of continuity for function f belonging to a particular weighted subspace of C[0,~) and show that it has some properties of ordinary modulus of continuity. We obtain some estimates of approximation of functions ... Keywords: Beurling classes, Modulus of continuity, Positive linear operators, Weighted spaces

A. D. Gadjiev; A. Aral

2007-07-01T23:59:59.000Z

394

Approximation of optimal moving paths of huge robot reclaimer with a 3d range finder  

Science Conference Proceedings (OSTI)

This paper proposes a simple method for approximating the optimal moving paths of a huge robot reclaimer located in the outdoor material stock yard with emphasis on safety, energy consumption, and transfer time. The reclaimer is equipped with a 3D range ...

Kwan-Hee Lee; Hyo-Jung Bae; Sung-Je Hong

2006-05-01T23:59:59.000Z

395

An approximate algorithm for the flux from a rectangular volume source  

SciTech Connect

An exact semi-analytic formula for the flux from a rectangular surface source with a slab shield has been derived and the required function table has been calculated. This formula is the basis for an algorithm which gives a good approximation for the flux from a rectangular volume source. No other hand calculation method for this source geometry is available in the literature.

Wallace, O.J.

1994-11-09T23:59:59.000Z

396

A O(1/?2)n-time sieving algorithm for approximate integer programming  

Science Conference Proceedings (OSTI)

The Integer Programming Problem (IP) for a polytope P??n is to find an integer point in P or decide that P is integer free. We give a randomized algorithm for an approximate version of this problem, ... Keywords: closest vector problem, integer programming, shortest vector problem

Daniel Dadush

2012-04-01T23:59:59.000Z

397

Approximate Equations of Motion for Compact Spinning Bodies in General Relativity  

E-Print Network (OSTI)

Approximate equations are derived for the motion of a gyroscope on the earth's gravitational field using the Einstein, Infeld, Hoffmann surface integral method. This method does not require a knowledge of the energy-momentum-stress tensor associated with the gyroscope and uses only its exterior field for its characterization. The resulting equations of motion differ from those of previous derivations.

James L. Anderson

2005-11-16T23:59:59.000Z

398

Approximation and error estimation in high dimensional space for stochastic collocation methods on arbitrary sparse samples  

Science Conference Proceedings (OSTI)

We have develop a fast method that can capture piecewise smooth functions in high dimensions with high order and low computational cost. This method can be used for both approximation and error estimation of stochastic simulations where the computations can either be guided or come from a legacy database.

Archibald, Richard K [ORNL; Deiterding, Ralf [ORNL; Hauck, Cory D [ORNL; Jakeman, John D [ORNL; Xiu, Dongbin [ORNL

2012-01-01T23:59:59.000Z

399

Approximate posterior distributions for convolutional two-level hidden Markov models  

Science Conference Proceedings (OSTI)

A convolutional two-level hidden Markov model is defined and evaluated. The bottom level contains an unobserved categorical Markov chain, and given the variables in this level the middle level contains unobserved conditionally independent Gaussian variables. ... Keywords: Approximation, Convolution, Forward-backward algorithm, Hidden Markov model, Seismic inversion

Kjartan Rimstad; Henning Omre

2013-02-01T23:59:59.000Z

400

Approximate forward-backward algorithm for a switching linear Gaussian model  

Science Conference Proceedings (OSTI)

A hidden Markov model with two hidden layers is considered. The bottom layer is a Markov chain and given this the variables in the second hidden layer are assumed conditionally independent and Gaussian distributed. The observation process is Gaussian ... Keywords: Approximation, Forward-backward algorithm, Hidden Markov model, Metropolis-Hastings algorithm, Seismic inversion

Hugo Hammer; Håkon Tjelmeland

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Two approximations of the present value distribution of a disability annuity  

Science Conference Proceedings (OSTI)

The distribution function of the present value of a cash flow can be approximated by means of a distribution function of a random variable, which is also the present value of a sequence of payments, but with a simpler structure. The corresponding random ... Keywords: Comonotonic joint distribution, Convex order, Multistate life insurance contracts, Present value distributions

Jaap Spreeuw

2006-02-01T23:59:59.000Z

402

Two approximations of the present value distribution of a disability annuity  

Science Conference Proceedings (OSTI)

The distribution function of the present value of a cash flow can be approximated by means of a distribution function of a random variable, which is also the present value of a sequence of payments, but with a simpler structure. The corresponding random ... Keywords: comonotonic joint distribution, convex order, multistate life insurance contracts, present value distributions

Jaap Spreeuw

2006-02-01T23:59:59.000Z

403

Optimal Policies and Approximations for a Bayesian Linear Regression Inventory Model  

Science Conference Proceedings (OSTI)

In this paper, we consider a periodic review inventory problem where demand in each period is modeled by linear regression. We use a Bayesian formulation to update the regression parameters as new information becomes available. We find that a state-dependent ... Keywords: Bayesian regression, approximations heuristics, inventory production, stochastic models

Katy S. Azoury; Julia Miyaoka

2009-05-01T23:59:59.000Z

404

Programs in Mathematica relevant to Phase Integral Approximation for coupled ODEs of the Schrödinger type  

E-Print Network (OSTI)

Three programs in Mathematica are presented, which produce expressions for the lowest order and the higher order corrections of the Phase Integral Approximation. First program is pertinent to one ordinary differential equation of the Schr\\"odinger type. The remaining two refer to a set of two such equations.

Andrzej A. Skorupski

2007-10-29T23:59:59.000Z

405

Algorithm for stochastic approximation with trial input perturbation in the nonstationary problem of optimization  

Science Conference Proceedings (OSTI)

Consideration was given to the randomized stochastic approximation algorithm with simultaneous trial input perturbation and two measurements used to optimize the unconstrained nonstationary functional. The upper boundary of the mean-square residual was ... Keywords: 02.50.Sk, 02.60.Pn

A. T. Vakhitov; O. N. Granichin; L. S. Gurevich

2009-11-01T23:59:59.000Z

406

Tensor Product Approximation (DMRG) and Coupled Cluster method in Quantum Chemistry  

E-Print Network (OSTI)

We present the Copupled Cluster (CC) method and the Density matrix Renormalization Grooup (DMRG) method in a unified way, from the perspective of recent developments in tensor product approximation. We present an introduction into recently developed hierarchical tensor representations, in particular tensor trains which are matrix product states in physics language. The discrete equations of full CI approximation applied to the electronic Schr\\"odinger equation is casted into a tensorial framework in form of the second quantization. A further approximation is performed afterwards by tensor approximation within a hierarchical format or equivalently a tree tensor network. We establish the (differential) geometry of low rank hierarchical tensors and apply the Driac Frenkel principle to reduce the original high-dimensional problem to low dimensions. The DMRG algorithm is established as an optimization method in this format with alternating directional search. We briefly introduce the CC method and refer to our theoretical results. We compare this approach in the present discrete formulation with the CC method and its underlying exponential parametrization.

Örs Legeza; Thorsten Rohwedder; Reinhold Schneider; Szilárd Szalay

2013-10-10T23:59:59.000Z

407

A New 2D-Transport, 1D-Diffusion Approximation of the Boltzmann Transport equation  

Science Conference Proceedings (OSTI)

The work performed in this project consisted of the derivation, implementation, and testing of a new, computationally advantageous approximation to the 3D Boltz- mann transport equation. The solution of the Boltzmann equation is the neutron flux in nuclear reactor cores and shields, but solving this equation is difficult and costly. The new “2D/1D” approximation takes advantage of a special geometric feature of typical 3D reactors to approximate the neutron transport physics in a specific (ax- ial) direction, but not in the other two (radial) directions. The resulting equation is much less expensive to solve computationally, and its solutions are expected to be sufficiently accurate for many practical problems. In this project we formulated the new equation, discretized it using standard methods, developed a stable itera- tion scheme for solving the equation, implemented the new numerical scheme in the MPACT code, and tested the method on several realistic problems. All the hoped- for features of this new approximation were seen. For large, difficult problems, the resulting 2D/1D solution is highly accurate, and is calculated about 100 times faster than a 3D discrete ordinates simulation.

Larsen, Edward

2013-06-17T23:59:59.000Z

408

FilMINT: An Outer Approximation-Based Solver for Convex Mixed-Integer Nonlinear Programs  

Science Conference Proceedings (OSTI)

We describe a new solver for convex mixed-integer nonlinear programs (MINLPs) that implements a linearization-based algorithm. The solver is based on an algorithm of Quesada and Grossmann [Quesada, I., I. E. Grossmann. 1992. An LP/NLP based branch-and-bound ... Keywords: LP/NLP-based branch and bound, mixed-integer nonlinear programming, outer approximation

Kumar Abhishek; Sven Leyffer; Jeff Linderoth

2010-10-01T23:59:59.000Z

409

Optimal approximation of linear systems using Taguchi-sliding-based differential evolution algorithm  

Science Conference Proceedings (OSTI)

A Taguchi-sliding-based differential evolution algorithm (TSBDEA) is proposed in this study to solve the problem of optimally approximating linear systems. The TSBDEA is an approach of combining the differential evolution algorithm (DEA) with the Taguchi-sliding-level-method ... Keywords: Differential evolution algorithm, Model reduction, Taguchi sliding level method

Jinn-Tsong Tsai; Wen-Hsien Ho; Jyh-Horng Chou; Ching-Yi Guo

2011-03-01T23:59:59.000Z

410

Approximation algorithm for minimal convergecast time problem in wireless sensor networks  

Science Conference Proceedings (OSTI)

In this paper we consider how to collect data from sensors deployed in the Euclidean plane in a time-efficient way. We assume that all sensors could adjust their transmission ranges and aggregate data received from other sensors. We adopt a collision-free ... Keywords: Approximation algorithm, Convergecast, Latency, Wireless sensor networks

Weiping Shang; Pengjun Wan; Xiaodong Hu

2010-07-01T23:59:59.000Z

411

An approximate two-dimensional Riemann solver for hyperbolic systems of conservation laws  

Science Conference Proceedings (OSTI)

A two-dimensional Riemann solver is proposed for the solution of hyperbolic systems of conservation laws in two dimensions of space. The solver approximates the solution of a so-called angular two-dimensional Riemann problem as the weighted sum of the ... Keywords: Conservation laws, Godunov-type schemes, Riemann solver, Shallow-water equations, Shock waves, Source term discretization

Vincent Guinot

2005-05-01T23:59:59.000Z

412

Definition of Systematic, Approximately Separable and Modular Internal Coordinates (SASMIC) for macromolecular simulation  

E-Print Network (OSTI)

A set of rules is defined to systematically number the groups and the atoms of organic molecules and, particularly, of polypeptides in a modular manner. Supported by this numeration, a set of internal coordinates is defined. These coordinates (termed Systematic, Approximately Separable and Modular Internal Coordinates, SASMIC) are straightforwardly written in Z-matrix form and may be directly implemented in typical Quantum Chemistry packages. A number of Perl scripts that automatically generate the Z-matrix files for polypeptides are provided as supplementary material. The main difference with other Z-matrix-like coordinates normally used in the literature is that normal dihedral angles (``principal dihedrals'' in this work) are only used to fix the orientation of whole groups and a somewhat non-standard type of dihedrals, termed ``phase dihedrals'', are used to describe the covalent structure inside the groups. This physical approach allows to approximately separate soft and hard movements of the molecule using only topological information and to directly implement constraints. As an application, we use the coordinates defined and ab initio quantum mechanical calculations to assess the commonly assumed approximation of the free energy, obtained from ``integrating out'' the side chain degree of freedom chi, by the Potential Energy Surface (PES) in the protected dipeptide HCO-L-Ala-NH2. We also present a sub-box of the Hessian matrix in two different sets of coordinates to illustrate the approximate separation of soft and hard movements when the coordinates defined in this work are used.

Pablo Echenique; J. L. Alonso

2005-11-03T23:59:59.000Z

413

A two-phase approximation for model checking probabilistic unbounded until properties of probabilistic systems  

Science Conference Proceedings (OSTI)

We have developed a new approximate probabilistic model-checking method for untimed properties in probabilistic systems, expressed in a probabilistic temporal logic (PCTL, CSL). This method, in contrast to the existing ones, does not require the ... Keywords: CSL, CTMC, DTMC, PCTL

Paul Jennings; Arka P. Ghosh; Samik Basu

2012-06-01T23:59:59.000Z

414

On the applicability of the minimal configured hierarchical fuzzy control and its relevance to function approximation  

Science Conference Proceedings (OSTI)

This paper presents an approach to minimal hierarchical fuzzy control systems design. It maintains the idea of distributing behaviors inside a fuzzy structure, while the minimal hierarchical fuzzy control is an effective procedure for dealing with systems ... Keywords: ANFIS, Behavioral decomposition, Control, Design, FIS, FLU, Function approximation, Hierarchical fuzzy systems, MCANHFLS, Methodology, RMSE, TSK

Taher M. Jelleli; Adel M. Alimi

2009-09-01T23:59:59.000Z

415

On the Approximation of the Coriolis Terms in C-Grid Models  

Science Conference Proceedings (OSTI)

A new representation of the Coriolis terms on the Arakawa C grid is proposed. The approximation dumps the grid-scale noise that arises because of spatial averaging of the Coriolis terms when the grid spacing is larger than the deformation radius. ...

Dmitri Nechaev; Max Yaremchuk

2004-09-01T23:59:59.000Z

416

Entanglement in GaAs and CdSe quantum dots: Exact calculations and DFT approximations  

Science Conference Proceedings (OSTI)

We consider two electrons confined in spherical GaAs and CdSe quantum dots and calculate their ground-state spatial entanglement exactly within a parabolic confinement model. We propose a perturbative scheme to approximate the above entanglement within ... Keywords: Density-functional theory, Entanglement, Quantum dots, Quantum information, Semiconductors

J. P. Coe; A. Sudbery; I. D'Amico

2009-03-01T23:59:59.000Z

417

An Approximate Dynamic Programming Algorithm for Large-Scale Fleet Management: A Case Application  

Science Conference Proceedings (OSTI)

We addressed the problem of developing a model to simulate at a high level of detail the movements of over 6,000 drivers for Schneider National, the largest truckload motor carrier in the United States. The goal of the model was not to obtain a better ... Keywords: approximate dynamic programming, driver management, fleet management, truckload trucking

Hugo P. Simão; Jeff Day; Abraham P. George; Ted Gifford; John Nienow; Warren B. Powell

2009-05-01T23:59:59.000Z

418

Preprint of the paper: "Stability analysis of BEM approximate solutions in grounding analysis"  

E-Print Network (OSTI)

the grounding grid its main element. In general, most of grounding grids of electrical substations consist thrusted ground rods in certain places of the substation site. The most important parametersPreprint of the paper: "Stability analysis of BEM approximate solutions in grounding analysis" J

Colominas, Ignasi

419

Pseudo-Linear Approximations for ARX Ciphers With Application to Threefish  

E-Print Network (OSTI)

Kay and Poorvi L. Vora The George Washington University, Washington DC 20052, USA kerry@gwu.edu and poorvi examine a window (grouping of contiguous bits) of size w for w observations. First, addition modulo 2n on the window can be approximated by addition modulo 2w . Second

International Association for Cryptologic Research (IACR)

420

Approximation Algorithms for Deadline-TSP and Vehicle Routing with Time-Windows  

E-Print Network (OSTI)

Approximation Algorithms for Deadline-TSP and Vehicle Routing with Time-Windows Nikhil Bansal by their deadlines. We also consider the more general Vehicle Routing with Time- Windows problem, in which each node their "time-windows" [R(v), D(v)]. No good ap- proximations were known previously for these problems

Sheridan, Jennifer

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Approximate eigensolutions of the deformed Woods-Saxon potential via AIM  

E-Print Network (OSTI)

By using the Pekeris approximation, the Schr\\"{o}dinger equation is solved for the nuclear deformed Woods-Saxon potential within the framework of the asymptotic iteration method (AIM). The energy levels are worked out and the corresponding normalized eigenfunctions are obtained in terms of hypergeometric function.

Sameer M. Ikhdair; Babatunde James Falaye; Majid Hamzavi

2013-07-31T23:59:59.000Z

422

On the angular defect of triangulations and the pointwise approximation of curvatures  

Science Conference Proceedings (OSTI)

Let S be a smooth surface of E3, p a point on S, km, kM, kG and kH the maximum, minimum, Gauss and mean curvatures of S at p. Consider a set {pippi+1}i ... Keywords: approximations, curvatures, differential geometry, meshes, smooth surfaces

V. Borrelli; F. Cazals; J.-M. Morvan

2003-09-01T23:59:59.000Z

423

tribution and abundance. In analysis of survey data, these results are a first approximation of correction  

E-Print Network (OSTI)

variables affecting aerial surveys, but the effects of glare on shipboard surveys and observer variabilitytribution and abundance. In analysis of survey data, these results are a first approximation conditions or animal behavior. Further work on survey methodology should examine the effect of eye height

424

Physics 116C Fall 2012 The Normal Approximation to the Binomial Distribution  

E-Print Network (OSTI)

Physics 116C Fall 2012 The Normal Approximation to the Binomial Distribution 1. Properties of the binomial distribution Consider a the binomial distribution, f(x) = C(n, x)px qn-x , where C(n, x) n! x of the binomial distribution can be computed using the follow- ing trick. Consider the binomial expansion (p + q

California at Santa Cruz, University of

425

Physics 116C Fall 2012 The Normal Approximation to the Binomial Distribution  

E-Print Network (OSTI)

Physics 116C Fall 2012 The Normal Approximation to the Binomial Distribution 1. Properties of the binomial distribution Consider a the binomial distribution, f(x) = C(n, x)p x q n-x , where C(n, x) # n! x. The expectation value of the binomial distribution can be computed using the follow­ ing trick. Consider

California at Santa Cruz, University of

426

Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model  

NLE Websites -- All DOE Office Websites (Extended Search)

Tests of Monte Carlo Independent Column Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model Petri Simo Järvenoja Heikki Järvinen Räisänen Finnish Meteorological Institute Figure 1. Root-mean-square sampling errors in local instant- aneous total (LW+SW) net flux at the surface and total radiative heating rate for the 1COL, CLDS, and REF approaches. Global rms values are given at the upper right hand corner of the plots. 1. Introduction The Monte Carlo Independent Column Approximation (McICA) separates the description of unresolved cloud structure from the radiative transfer solver very flexible ! unbiased with respect to ICA ! However, the radiative fluxes and heating rates contain conditional random errors ("McICA noise"). ? The topic of this poster: All previous tests of McICA

427

Low-frequency plasma conductivity in the average-atom approximation  

E-Print Network (OSTI)

Low-frequency properties of a plasma are examined within the average-atom approximation, which presumes that scattering of a conducting electron on each atom takes place independently of other atoms. The relaxation time tau distinguishes a high-frequency region omega tau > 1, where the single-atom approximation is applicable explicitly, from extreme low frequencies omega tau 1, reproducing the Ziman formula in the static limit, results based on the Kubo-Greenwood formula for high frequencies, and satisfying the conductivity sum-rule precisely. The correspondence between physical processes leading to the conventional Ohm's law and the infrared properties of QED is discussed. The suggested average-atom approach to frequency-dependent conductivity is illustrated by numerical calculations for the an aluminum plasma in the temperature range 2--10 eV.

Kuchiev, M Yu

2008-01-01T23:59:59.000Z

428

Probing the nonlocal approximation to resonant collisions ofelectrons with diatomic molecules  

SciTech Connect

A numerically solvable two-dimensional model introduced bythe authors [Phys. Rev. A 73, 032721 (2006)]is used to investigate thevalidity of the nonlocal approximation to the dynamics of resonantcollisions of electrons with diatomic molecules. The nonlocalapproximation to this model is derived in detail, all underlyingassumptions are specified and explicit expressions for the resonant andnon-resonant (background) T matrix for the studied processes are given.Different choices of the so-called discrete state, which fully determinesthe nonlocal approximation, are discussedand it is shown that a physicalchoice of this state can in general give poorer results than otherchoices that minimize the non-adiabatic effects and/or the backgroundterms of the T matrix. The background contributions to the crosssections, which are usually not considered in the resonant theory ofelectron-molecule collisions, can be significant not only for elasticscattering but also for the inelastic process of vibrationalexcitation.

Houfek, Karel; Rescigno, Thomas N.; McCurdy, C. William

2007-09-07T23:59:59.000Z

429

B-Spline Surface Approximation to Cross-Sections Using Distance Maps  

E-Print Network (OSTI)

this paper, we present a method of surface approximation to cross-sections with multiple branching problems. In this method, we first decompose each multiple branching problem into a set of single branching problems by providing a set of intermediate contours using distance maps. For each single branching region, a procedure then performs the skinning of contour curves represented by cubic B-spline curves on a common knot vector, each of which is fitted to its contour points within a given accuracy. In order to acquire a more compact representation for the surface, the method includes an algorithm for reducing the number of knots in the common knot vector. The approximation surface to the crosssections is represented by a set of bicubic B-spline surfaces. This method provides a smooth surface model, yet realises efficient data reduction.

J. Jeong; K. Kim; H. Park; H. Cho; M. Jung

1999-01-01T23:59:59.000Z

430

LinguisticBelief: a java application for linguistic evaluation using belief, fuzzy sets, and approximate reasoning.  

Science Conference Proceedings (OSTI)

LinguisticBelief is a Java computer code that evaluates combinations of linguistic variables using an approximate reasoning rule base. Each variable is comprised of fuzzy sets, and a rule base describes the reasoning on combinations of variables fuzzy sets. Uncertainty is considered and propagated through the rule base using the belief/plausibility measure. The mathematics of fuzzy sets, approximate reasoning, and belief/ plausibility are complex. Without an automated tool, this complexity precludes their application to all but the simplest of problems. LinguisticBelief automates the use of these techniques, allowing complex problems to be evaluated easily. LinguisticBelief can be used free of charge on any Windows XP machine. This report documents the use and structure of the LinguisticBelief code, and the deployment package for installation client machines.

Darby, John L.

2007-03-01T23:59:59.000Z

431

Coupled-cluster method: A lattice-path-based subsystem approximation scheme for quantum lattice models  

Science Conference Proceedings (OSTI)

An approximation hierarchy, called the lattice-path-based subsystem (LPSUBm) approximation scheme, is described for the coupled-cluster method (CCM). It is applicable to systems defined on a regular spatial lattice. We then apply it to two well-studied prototypical (spin-(1/2) Heisenberg antiferromagnetic) spin-lattice models, namely, the XXZ and the XY models on the square lattice in two dimensions. Results are obtained in each case for the ground-state energy, the ground-state sublattice magnetization, and the quantum critical point. They are all in good agreement with those from such alternative methods as spin-wave theory, series expansions, quantum Monte Carlo methods, and the CCM using the alternative lattice-animal-based subsystem (LSUBm) and the distance-based subsystem (DSUBm) schemes. Each of the three CCM schemes (LSUBm, DSUBm, and LPSUBm) for use with systems defined on a regular spatial lattice is shown to have its own advantages in particular applications.

Bishop, R. F.; Li, P. H. Y. [School of Physics and Astronomy, Schuster Building, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-04-15T23:59:59.000Z

432

Stat 503-1 Lecture 1 Mon. Aug. 22, 2011 Course Information and Policies [go over, office hours and midterm dates  

E-Print Network (OSTI)

.1.6) Study the relationships of body size and energy expenditure. Researchers measured fat-free body mass and 24-hour energy expenditure (repeated twice) for seven men. #12;2 Subject Energy- expenditure (in Kcal consumption and cholesterol levels (mg/dl). #12;3 - Study 2: Match subjects with gender, similar age

Xie, Jun

433

Campus Crusade for Christ sponsors the nationally-financed PORN NATION, a one-hour multimedia event of faith-based testimony by  

E-Print Network (OSTI)

Campus Crusade for Christ sponsors the nationally-financed PORN NATION, a one-hour multimedia event of the American media. Leahy supplements this PORN NATION show with lectures at Baptist churches on the "maintenance of sexual purity and integrity." PORN and the Chris ian NATION Wedge Is sex inherently SINFUL

Gleeson, Joseph G.

434

The Influence of Variations in Surface Treatment on 24-Hour Forecasts with a Limited Area Model, Including a Comparison of Modeled and Satellite-Measured Surface Temperatures  

Science Conference Proceedings (OSTI)

The effect of variations in surface parameters on 24-hour limited area forecasts has been examined on a day in July 1981. The vehicle for the study is a ten-level primitive equation model covering most of the continental United States. Variations ...

George Diak; Stacey Heikkinen; John Rates

1986-01-01T23:59:59.000Z

435

Instructor's Name Email Address Office Hours Alvarado, Jimena jimena@pdx.edu W 9:00-10:00am CH 368  

E-Print Network (OSTI)

:00-5:30pm CH 366 Olmsted, John (TA - Chris Harper) olmstedj@pdx.edu M 4:30-5:30pm CH 311 Spring 2011 Instructor Office Hours #12;Patka, Mazna (TA - Colleen Kidney) mpatka@pdx.edu TR 10:00-11:00am CH 367 Pickett

436

A Neural Networks–Based Fusion Technique to Estimate Half-Hourly Rainfall Estimates at 0.1° Resolution from Satellite Passive Microwave and Infrared Data  

Science Conference Proceedings (OSTI)

The purpose of this paper is to evaluate a new operational procedure to produce half-hourly rainfall estimates at 0.1° spatial resolution. Rainfall is estimated using a neural networks (NN)–based approach utilizing passive microwave (PMW) and ...

Francisco J. Tapiador; Chris Kidd; Vincenzo Levizzani; Frank S. Marzano

2004-04-01T23:59:59.000Z

437

Time-dependent Generalized SIC-OEP formalism and Generalized SIC-Slater approximation  

E-Print Network (OSTI)

We propose a simplification of the full "2 sets" Time dependent Self Interaction Correction (TD-SIC) method, applying the Optimized Effective Potential (OEP) method. The new resulting scheme is called time-dependent "Generalized SIC-OEP". A straightforward approximation, using the spatial localization of one set of orbitals, leads to the "Generalized SIC-Slater" formalism. We show that it represents a great improvement compared to the traditional SIC-Slater/KLI formalisms.

Messud, J; Reinhard, P -G; Suraud, E

2009-01-01T23:59:59.000Z

438

Time-dependent Generalized SIC-OEP formalism and Generalized SIC-Slater approximation  

E-Print Network (OSTI)

We propose a simplification of the full "2 sets" Time dependent Self Interaction Correction (TD-SIC) method, applying the Optimized Effective Potential (OEP) method. The new resulting scheme is called time-dependent "Generalized SIC-OEP". A straightforward approximation, using the spatial localization of one set of orbitals, leads to the "Generalized SIC-Slater" formalism. We show that it represents a great improvement compared to the traditional SIC-Slater/KLI formalisms.

J. Messud; P. M. Dinh; P. -G. Reinhard; E. Suraud

2009-08-06T23:59:59.000Z

439

Two-photon approximation in the theory of electron recombination in hydrogen  

Science Conference Proceedings (OSTI)

A rigorous quantum electrodynamics theory of the multiphoton decay of excited states in a hydrogen atom is presented. The ''two-photon'' approximation is formulated which is limited by the one- and two-photon transitions including cascade transitions with two-photon links. This may be helpful for the strict description of the recombination process in a hydrogen atom and, in principle, for the history of hydrogen recombination in the early universe.

Solovyev, D. [V. A. Fock Institute of Physics, St. Petersburg State University, Petrodvorets, Oulianovskaya 1, 198504 St. Petersburg (Russian Federation); Labzowsky, L. [V. A. Fock Institute of Physics, St. Petersburg State University, Petrodvorets, Oulianovskaya 1, 198504 St. Petersburg (Russian Federation); Petersburg Nuclear Physics Institute, Gatchina, 188300 St. Petersburg (Russian Federation)

2010-06-15T23:59:59.000Z

440

Geophysical imaging method utilizing backpropagation and zeroth-order phase approximation  

DOE Patents (OSTI)

A method is provided for determining, under field conditions and in near-real time, an image of a geophysical objective under the ground in a geophysical medium, utilizing a zeroth order phase approximation implemented with first signal-to-detector arrival times for a plurality of signal transmitters transmitting signals through the geologic medium and the geologic objective to a plurality of signal receivers, disposed adjacent to the geologic objective in a predetermined manner. 9 figs.

Witten, A.J.

1989-09-12T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Approximations of the operator exponential in a periodic diffusion problem with drift  

SciTech Connect

A Cauchy problem for a parabolic diffusion equation with 1-periodic coefficients containing first order terms is studied. For the corresponding semigroup we construct approximations in the L{sup 2}-operator norm on sections t=const of order O(t{sup -m/2}) as t{yields}{infinity} for m=1 or m=2. The spectral method based on the Bloch representation of an operator with periodic coefficients is used. Bibliography: 25 titles.

Pastukhova, Svetlana E [Moscow State Institute of Radio-Engineering, Electronics and Automation (Technical University), Moscow (Russian Federation)] [Moscow State Institute of Radio-Engineering, Electronics and Automation (Technical University), Moscow (Russian Federation)

2013-02-28T23:59:59.000Z

442

Approximate analytical solutions for nonlinear Emden-Fowler type equations by differential transform method  

E-Print Network (OSTI)

In this paper, approximate analytical solutions of nonlinear Emden-Fowler type equations are obtained by the differential transform method (DTM). The DTM is a numerical as well as analytical method for solving integral equations, ordinary and partial diferential equations. To show the efficiency of the DTM, some examples are presented. Comparisons with exact solution show that the DTM is a powerful method for the solution of the nonlinear Emden-Fowler type equations.

Birol Ibis

2012-11-15T23:59:59.000Z

443

The development of an approximate dynamic analysis of insulating glass units  

E-Print Network (OSTI)

The goal of this thesis is to develop an approximate dynamic analysis of sealed insulating glass (IG) units subject to uniform blast loads, the formulation of which will be incorporated into a computer program that will be used as a tool to estimate their dynamic response. The formulation of this approximate dynamic analysis of IG units is achieved by modeling the unit with two equivalent single degree of freedom systems consisting of equivalent masses, equivalent structural stiffnesses, equivalent forces, and by incorporating air space compatibility relationships into this model. The equations of motion which define the behavior of this dynamic model are incorporated into a computer program that computes the dynamic response of an IG unit subjected to a prescribed blast loading. This response includes the displacements, velocities, and accelerations of the glass plates of the IG unit. The blast loading will be idealized in order to simplify the analysis. The program will approximate the positive pressure phase of a blast load with an equivalent triangular loading. IG units designed by existing methods will be analyzed using the program, and their performance evaluated. This analysis will not only provide valuable data on the behavior of the IG units to blast loadings, but will lend insight into the acceptability of the existing design approach. The results will also indicate the acceptability of the technique developed in this thesis as a tool in the design and analysis of IG units subject to blast loads.

Sequeira, Miguel Angel

1995-01-01T23:59:59.000Z

444

The InterHourly-Variability (IHV) Index of Geomagnetic Activity and its Use in Deriving the Long-term Variation of Solar Wind Speed  

E-Print Network (OSTI)

We describe the derivation of the InterHourly Variability (IHV) index of geomagnetic activity. The IHV-index for a geomagnetic element is mechanically derived from hourly values as the sum of the unsigned differences between adjacent hours over a seven-hour interval centered on local midnight. The index is derived separately for stations in both hemispheres within six longitude sectors using only local night hours. It is intended as a long-term index. Available data allows derivation of the index back well into the 19th century. On a time scale of a 27-day Bartels rotation, IHV averages for stations with corrected geomagnetic latitude less than 55 degrees are strongly correlated with midlatitude range indices. Assuming a constant calibration of the aa-index we find that observed yearly values of aa before the year 1957 are 2.9 nT too small compared to values calculated from IHV using the regression constants based on 1980-2004. We interpret this discrepancy as an indication that the calibration of the aa index is in error before 1957. There is no such problem with the ap index. Rotation averages of IHV are also strongly correlated with solar wind parameters (BV^2). On a time scale of a year combining the IHV-index and the recently-developed Inter-Diurnal Variability (IDV) index (giving B) allows determination of solar wind speed, V, from 1890-present. Over the ~120-year series, the yearly mean solar wind speed varied from a low of 303 km/s in 1902 to a high value of 545 km/s in 2003. The calculated yearly values of the product BV using B and V separately derived from IDV and IHV agree quantitatively with (completely independent) BV derived from the amplitude of the diurnal variation of the H component in the polar caps since 1926 and sporadically beyond.

Leif Svalgaard; Edward W. Cliver

2007-06-07T23:59:59.000Z

445

AN EFFICIENT APPROXIMATION OF THE CORONAL HEATING RATE FOR USE IN GLOBAL SUN–HELIOSPHERE SIMULATIONS  

E-Print Network (OSTI)

The origins of the hot solar corona and the supersonically expanding solar wind are still the subject of debate. A key obstacle in the way of producing realistic simulations of the Sun–heliosphere system is the lack of a physically motivated way of specifying the coronal heating rate. Recent one-dimensional models have been found to reproduce many observed features of the solar wind by assuming the energy comes from Alfvén waves that are partially reflected, then dissipated by magnetohydrodynamic turbulence. However, the nonlocal physics of wave reflection has made it difficult to apply these processes to more sophisticated (three-dimensional) models. This paper presents a set of robust approximations to the solutions of the linear Alfvén wave reflection equations. A key ingredient of the turbulent heating rate is the ratio of inward-to-outward wave power, and the approximations developed here allow this to be written explicitly in terms of local plasma properties at any given location. The coronal heating also depends on the frequency spectrum of Alfvén waves in the open-field corona, which has not yet been measured directly. A modelbased assumption is used here for the spectrum, but the results of future measurements can be incorporated easily. The resulting expression for the coronal heating rate is self-contained, computationally efficient, and applicable directly to global models of the corona and heliosphere. This paper tests and validates the approximations by comparing the results to exact solutions of the wave transport equations in several cases relevant to the fast and slow solar wind. Key words: interplanetary medium – magnetohydrodynamics (MHD) – solar wind – Sun: corona – turbulence – waves Online-only material: tar file of source code 1.

Steven R. Cranmer

2010-01-01T23:59:59.000Z

446

When is the two-level approximation untenable in issues of Decoherence?  

E-Print Network (OSTI)

We examine the conditions in favor and necessity of a realistic multileveled description of a decohering quantum system. Under these conditions approximate techniques to simplify a multileveled system by its first two levels is unreliable and a realistic multilevel description in the formulation of decoherence is unavoidable. In this regard, our first crucial observation is that, the validity of the two level approximation of a multileveled system is not controlled purely by {\\it sufficiently low temperatures}. We demonstrate using three different environmental spectral models that the type of system-environment coupling and the environmental spectrum have a dominant role over the temperature. Particularly, zero temperature quantum fluctuations induced by the Caldeira-Leggett type linear coordinate coupling can be influential in a wide energy range in the systems allowed transitions. The second crucial observation against the validity of the two level approximation is that the decoherence times being among the system's short time scales are found to be dominated not by the resonant but {\\it non-resonant} processes. We demonstrate this in three stages. Firstly, our zero temperature numerical calculations reveal that, the calculated decoherence rates including relaxation, dephasing and leakage phenomena show, a linear dependence on the spectral area for all spectral models used, independent from the spectral shape within a large environmental spectral range compared to the quantum system's energies. Secondly, within the same range, the decoherence times only have a marginal dependence on the translations of the entire frequency spectrum. Finally, the same decoherence rates show strong dependence on the number of coupled levels by the system-environment coupling.

Kerim Savran; Tugrul Hakioglu; Emine Mese

2004-06-22T23:59:59.000Z

447

Parallel FE Approximation of the Even/Odd Parity Form of the Linear Boltzmann Equation  

Science Conference Proceedings (OSTI)

A novel solution method has been developed to solve the linear Boltzmann equation on an unstructured triangular mesh. Instead of tackling the first-order form of the equation, this approach is based on the even/odd-parity form in conjunction with the conventional mdtigroup discrete-ordinates approximation. The finite element method is used to treat the spatial dependence. The solution method is unique in that the space-direction dependence is solved simultaneously, eliminating the need for the conventional inner iterations, and the method is well suited for massively parallel computers.

Drumm, Clifton R.; Lorenz, Jens

1999-07-21T23:59:59.000Z

448

Post-quasistatic approximation as a test bed for numerical relativity  

Science Conference Proceedings (OSTI)

It is shown that observers in the standard ADM 3+1 treatment of matter are the same as the observers used in the matter treatment of Bondi: they are comoving and local Minkowskian. Bondi's observers are the basis of the post-quasistatic approximation (PQSA) to study a contracting distribution of matter. This correspondence suggests the possibility of using the PQSA as a test bed for numerical relativity. The treatment of matter by the PQSA and its connection with the ADM 3+1 treatment are presented, for its practical use as a calibration tool and as a test bed for numerical relativistic hydrodynamic codes.

Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

2009-05-15T23:59:59.000Z

449

p-barp-Annihilation processes in the tree approximation of SU(3) chiral effective theory  

Science Conference Proceedings (OSTI)

The p-barp-annihilation reactions p-barp {yields} {eta}{eta} {eta} and p-barp {yields} {eta}KK-bar at rest are considered in the tree approximation in the framework of SU(3) chiral effective theory at leading order. The calculated branchings are compared with the data. The results for neutral ({eta}{eta}{eta}, K{sup 0}K-bar{sup 0}{sub {eta}}) and charged (K{sup +}K{sup -}{sub {eta}}) channels are essentially different.

Tarasov, V. E.; Kudryavtsev, A. E., E-mail: kudryavt@itep.ru; Romanov, A. I.; Weinberg, V. M. [Institute of Theoretical and Experimental Physics (Russian Federation)

2012-12-15T23:59:59.000Z

450

Shock wave collisions in AdS5: approximate numerical solutions  

E-Print Network (OSTI)

We numerically study the evolution of a boost-invariant N=4 SYM medium using AdS/CFT. We consider a toy model for the collision of gravitational shock waves, finding that the energy density first increases, reaches a maximum and then starts to decrease, matching hydrodynamics for late times. For the initial conditions we consider, the hydrodynamic scale governing the late time behaviour is to very good approximation determined by the area of the black hole horizon at initial times. Our results provide a toy model for the early time evolution of the bulk system in heavy-ion collisions at RHIC and the LHC.

Bin Wu; Paul Romatschke

2011-08-18T23:59:59.000Z

451

Approximate Integrals of rf-driven Particle Motion in Magnetic Field  

DOE Green Energy (OSTI)

For a particle moving in nonuniform magnetic field under the action of an rf wave, ponderomotive effects result from rf-driven oscillations nonlinearly coupled with Larmor rotation. Using Lagrangian and Hamiltonian formalism, we show how, despite this coupling, two independent integrals of the particle motion are approximately conserved. Those are the magnetic moment of free Larmor rotation and the quasi-energy of the guiding center motion parallel to the magnetic field. Under the assumption of non-resonant interaction of the particle with the rf field, these integrals represent adiabatic invariants of the particle motion.

I.Y. Dodin; N.J. Fisch

2004-04-26T23:59:59.000Z

452

The low-energy nuclear density of states and the saddle point approximation  

E-Print Network (OSTI)

The nuclear density of states plays an important role in nuclear reactions. At high energies, above a few MeV, the nuclear density of states is well described by a formula that depends on the smooth single particle density of states at the Fermi surface, the nuclear shell correction and the pairing energy. In this paper we present an analysis of the low energy behaviour of the nuclear density of states using the saddle point approximation and extensions to it. Furthermore, we prescribe a simple parabolic form for excitation energy, in the low energy limit, which may facilitate an easy computation of level densities.

Sanjay K. Ghosh; Byron K. Jennings

2001-07-30T23:59:59.000Z

453

Optimal Design of Transonic Fan Blade Leading Edge Shape Using CFD and Simultaneous Perturbation Stochastic Approximation Method  

E-Print Network (OSTI)

Simultaneous Perturbation Stochastic Approximation method has attracted considerable application in many different areas such as statistical parameter estimation, feedback control, simulation-based optimization, signal & ...

Xing, X.Q.

454

Some numerical reslts on best uniform polynomial approximation of. chi. sup. alpha. on (0,1)  

Science Conference Proceedings (OSTI)

Let {alpha} be a positive number, and let E{sub n}(chi{sup {alpha}}; (0,1)) denote the error of best uniform approximation to {chi}{sup {alpha}}, by polynomials of degree at most n, on the interval (0,1). The Russian mathematician S.N. Bernstein established the existence of a nonnegative constant {Beta}({alpha}) such that {Beta}({alpha}):= {sub n{yields}{infinity}lim(2n){sup 2{alpha}}E{sub n}({chi}{sup {alpha}};(0.1)). In addition, Bernstein showed that {Beta}{alpha} 0) and that {Gamma}(2{alpha}){vert bar}sin({pi}{alpha}){vert bar}/{pi} (1{minus}1/2{alpha}{minus}1) {1/2}), so that the asymptotic behavior of {Beta}({alpha}) is known when {alpha}{yields}{infinity}. Still, the problem of trying to determine {Beta}({alpha}) more precisely, for all {alpha} > 0, is intriguing. To this end, we have rigorously determined the numbers for thirteen values of {alpha}, where these numbers were calculated with a precision of at least 200 significant digits. For each of these thirteen values of {alpha}, Richardson's extrapolation was applied to the products to obtain estimates of {Beta}({alpha}) to approximately 40 decimal places. Included are graphs of the points ({alpha},{Beta}({alpha})) for the thirteen values of {alpha} that we considered.

Carpenter, A.J.; Varga, R.S.

1992-01-01T23:59:59.000Z

455

Some numerical reslts on best uniform polynomial approximation of. chi. sup. alpha. on (0,1)  

SciTech Connect

Let {alpha} be a positive number, and let E{sub n}(chi{sup {alpha}}; (0,1)) denote the error of best uniform approximation to {chi}{sup {alpha}}, by polynomials of degree at most n, on the interval (0,1). The Russian mathematician S.N. Bernstein established the existence of a nonnegative constant {Beta}({alpha}) such that {Beta}({alpha}):= {sub n{yields}{infinity}lim(2n){sup 2{alpha}}E{sub n}({chi}{sup {alpha}};(0.1)). In addition, Bernstein showed that {Beta}{alpha} < {Gamma}(2{alpha}){vert bar}sin(pi}{alpha}){vert bar}/{pi} ({alpha} > 0) and that {Gamma}(2{alpha}){vert bar}sin({pi}{alpha}){vert bar}/{pi} (1{minus}1/2{alpha}{minus}1) < {Beta}({alpha}) ({alpha} > {1/2}), so that the asymptotic behavior of {Beta}({alpha}) is known when {alpha}{yields}{infinity}. Still, the problem of trying to determine {Beta}({alpha}) more precisely, for all {alpha} > 0, is intriguing. To this end, we have rigorously determined the numbers for thirteen values of {alpha}, where these numbers were calculated with a precision of at least 200 significant digits. For each of these thirteen values of {alpha}, Richardson's extrapolation was applied to the products to obtain estimates of {Beta}({alpha}) to approximately 40 decimal places. Included are graphs of the points ({alpha},{Beta}({alpha})) for the thirteen values of {alpha} that we considered.

Carpenter, A.J.; Varga, R.S.

1992-01-01T23:59:59.000Z

456

An application of distributed approximating functional-wavelets to reactive scattering  

SciTech Connect

A newly developed distributed approximating functional (DAF)-wavelet, the Dirichlet{endash}Gabor DAF-wavelet (DGDW), is applied in a calculation of the state-to-state reaction probabilities for the three-dimensional (3-D) (J=0)H+H{sub 2} reaction, using the time-independent wave-packet reactant-product decoupling (TIWRPD) method. The DGDWs are reconstructed from a rigorous mathematical sampling theorem, and are shown to be DAF-wavelet generalizations of both the sine discrete variable representation (sinc-DVR) and the Fourier distributed approximating functionals (DAFs). An important feature of the generalized sinc-DVR representation is that the grid points are distributed at equally spaced intervals and the kinetic energy matrix has a banded, Toeplitz structure. Test calculations show that, in accordance with mathematical sampling theory, the DAF-windowed sinc-DVR converges much more rapidly and to higher accuracy with bandwidth, 2W+1. The results of the H+H{sub 2} calculation are in very close agreement with the results of previous TIWRPD calculations, demonstrating that the DGDW representation is an accurate and efficient representation for use in FFT wave-packet propagation methods, and that, more generally, the theory of wavelets and related techniques have great potential for the study of molecular dynamics. {copyright} {ital 1998 American Institute of Physics.}

Wei, G.W.; Althorpe, S.C.; Kouri, D.J. [Department of Chemistry and Department of Physics, University of Houston, Houston, Texas77204-5641 (United States); Hoffman, D.K. [Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa50011 (United States)

1998-05-01T23:59:59.000Z

457

On the Elimination of Reactive Element Loops and the Useof Special Approximations in the Design of OTA-C Filters  

Science Conference Proceedings (OSTI)

Loops of reactive elements in passive filters cause a series of problems in OTA-C simulations of these structures. These loops can be eliminated in a systematic way by the procedures described in the paper. The use of special approximations in the ... Keywords: OTA-C filters, approximation, filters

Antonio Carlos M. De Queiroz; Luiz P. Caloba

1997-07-01T23:59:59.000Z

458

Determination of a control parameter in a one-dimensional parabolic equation using the moving least-square approximation  

Science Conference Proceedings (OSTI)

In this paper the approximation of moving least-square (MLS) is used for finding the solution of a one-dimensional parabolic inverse problem with source control parameter. Comparing with other numerical methods based on meshes such as finite difference ... Keywords: inverse problem, meshless method, moving least-square approximation, overspecification, parabolic equation

Rongjun Cheng

2008-09-01T23:59:59.000Z

459

Estimation of a new stochastic transform for solving the complex exponentials approximation problem: Computational aspects and applications  

Science Conference Proceedings (OSTI)

Many real life problems can be reduced to the solution of a complex exponentials approximation problem which is usually ill-posed. Recently a new transform for solving this problem, formulated as a specific moments problem in the plane, has been proposed ... Keywords: Complex moments problem, Logarithmic potentials, Padé approximants, Pencils of matrices, Random determinants

Piero Barone

2010-05-01T23:59:59.000Z

460

A scattered data approximation tool to map single-walled carbon nanotube dispersion to the processing parameters in polymer nanocomposites  

Science Conference Proceedings (OSTI)

The relationship of nanocomposite dispersion to dispersion techniques and other processing parameters was studied. Examining all permutations of the various factors in the laboratory is a challenging task. In this paper, we propose to map a correlation ... Keywords: CNTs, RBF, carbon nanotubes, classification, dispersion, feature selection, functional mapping, greedy algorithms, nanotechnology, polymer nanocomposites, polymer processing, radial basis function, scattered data approximation, sequential function approximation

Jonathan W. Lee; Andrew J. Meade; Enrique V. Barrera

2010-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

The d-bar approach to approximate inverse scattering at fixed energy in three dimensions  

E-Print Network (OSTI)

We develop the d-bar approach to inverse scattering at fixed energy in dimensions $d\\ge 3$ of [Beals, Coifman 1985] and [Henkin, Novikov 1987]. As a result we propose a stable method for nonlinear approximate finding a potential $v$ from its scattering amplitude $f$ at fixed energy $E>0$ in dimension $d=3$. In particular, in three dimensions we stably reconstruct n-times smooth potential $v$ with sufficient decay at infinity, $n>3$, from its scattering amplitude $f$ at fixed energy $E$ up to $O(E^{-(n-3-\\epsilon)/2})$ in the uniform norm as $E\\to +\\infty$ for any fixed arbitrary small $\\epsilon >0$ (that is with almost the same decay rate of the error for $E\\to +\\infty$ as in the linearized case near zero potential).

Roman Novikov

2005-05-10T23:59:59.000Z

462

Approximate Bregman near neighbors in sublinear time: Beyond the triangle inequality  

E-Print Network (OSTI)

Bregman divergences are important distance measures that are used extensively in data-driven applications such as computer vision, text mining, and speech processing, and are a key focus of interest in machine learning. Answering nearest neighbor (NN) queries under these measures very important in these applications and has been the subject of extensive study, but is problematic because these distance measures lack metric properties like symmetry and the triangle inequality. In this paper, we present the first approximate nearest-neighbor (ANN) algorithms, which run in polylog(n) time for Bregman divergences of fixed dimension. To do so, we explore two properties of Bregman divergences that are vital to the analysis: a reverse triangle inequality (RTI) and a relaxed triangle inequality called mu-defectiveness. We show that even though Bregman divergences do not satisfy the triangle inequality, the above properties can be utilized to design an efficient search data structure that follows the general two-stage ...

Abdullah, Amirali; Venkatasubramanian, Suresh

2011-01-01T23:59:59.000Z

463

Skyrme-Random-Phase-Approximation description of spin-flip and orbital giant resonances  

E-Print Network (OSTI)

The self-consistent separable random-phase approximation (SRPA) model with Skyrme forces is extended to the case of magnetic excitations and applied to the description of spin-flip and orbital M1 giant resonances in the isotopic chain $^{142-152}$Nd. The Skyrme forces SkT6, SkM*, SLy6 and SkI3 are used. The calculations show the onset of the scissors mode with increasing deformation. A specific three-peak structure of the spin-flip response is found and explained by particular neutron and proton spin-flip transitions. Although the employed forces provide an acceptable qualitative description, the Skyrme functional still needs further improvement to reproduce quantitatively the experimental data.

V. O. Nesterenko; J. Kvasil; P. Vesely; W. Kleinig; P. -G. Reinhard

2009-11-12T23:59:59.000Z

464

Applicability of Boussinesq approximation in a turbulent fluid with constant properties  

E-Print Network (OSTI)

The equations of motion describing buoyant fluids are often simplified using a set of approximations proposed by J. Boussinesq one century ago. To resume, they consist in assuming constant fluid properties, incompressibility and conservation of calories during heat transport. Assuming fulfilment of the first requirement (constant fluid properties), we derive a set of 4 criteria for assessing the validity of the two other requirements in turbulent Rayleigh-B\\'enard convection. The first criterion $\\alpha \\Delta \\ll 1 $ simply results from the incompressibility condition in the thermal boundary layer ($\\alpha$ and $\\Delta$ are the thermal expansion coefficient and the temperature difference driving the flow). The 3 other criteria are proportional or quadratic with the density stratification or, equivalently with the temperature difference resulting from the adiabatic gradient across the cell $\\Delta_{h}$. Numerical evaluations with air, water and cryogenic helium show that most laboratory experiments are free f...

Roche, Philippe-Emmanuel P -E

2007-01-01T23:59:59.000Z

465

Nuclear matter EOS with light clusters within the mean-field approximation  

E-Print Network (OSTI)

The crust of a neutron star is essentially determined by the low-density region ($\\rholight clusters in nuclear matter will be energetically favorable at finite temperature. At very low densities and moderate temperatures, the few body correlations are expected to become important and light nuclei like deuterons, tritons, helions and $\\alpha$-particles will form. Due to Pauli blocking, these clusters will dissolve at higher densities $\\rho\\gtrsim 0.1\\rho_0$. The presence of these clusters influences the cooling process and quantities, such as the neutrino emissivity and gravitational waves emission. The dissolution density of these light clusters, treated as point-like particles, will be studied within the Relativistic Mean Field approximation. In particular, the dependence of the dissolution density on the clusters-meson couplings is studied.

Márcio Ferreira; Constança Providência

2013-07-09T23:59:59.000Z

466

Low-lying states of heavy nuclei within the nucleon pair approximation  

Science Conference Proceedings (OSTI)

In this article we perform systematic calculations on low-lying states of 33 nuclei with A=202-212, using the nucleon pair approximation of the shell model. We use a phenomenological shell-model Hamiltonian that includes single-particle energies, monopole and quadrupole pairing interactions, and quadrupole-quadrupole interactions. The building blocks of our model space include one J=4 valence neutron pair, and one J=4,6,8 valence proton pair, in addition to the usual S and D pairs. We calculate binding energies, excitation energies, electric quadrupole and magnetic dipole moments of low-lying states, and E2 transition rates between low-lying states. Our calculated results are reasonably consistent with available experimental data. The calculated quadrupole moments and magnetic moments, many of which have not yet been measured for these nuclei, are useful for future experimental measurements.

Xu, Z. Y.; Lei, Y. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhao, Y. M. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); CCAST, World Laboratory, P.O. Box 8730, Beijing 100080 (China); Xu, S. W.; Xie, Y. X. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Arima, A. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Science Museum, Japan Science Foundation, 2-1 Kitanomaru-koen, Chiyoda-ku, Tokyo 102-0091 (Japan)

2009-05-15T23:59:59.000Z

467

Bayesian inference of solar and stellar magnetic fields in the weak-field approximation  

E-Print Network (OSTI)

The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for diagnosing magnetic fields in the solar and stellar atmospheres. A fully Bayesian approach to the inference of magnetic properties in unresolved structures is presented. The analytical expression for the marginal posterior distribution is obtained, from which we can obtain statistically relevant information about the model parameters. The role of a-priori information is discussed and a hierarchical procedure is presented that gives robust results that are almost insensitive to the precise election of the prior. The strength of the formalism is demonstrated through an application to IMaX data. Bayesian methods can optimally exploit data from filter-polarimeters given the scarcity of spectral information as compared with spectro-polarimeters. The effect of noise and how it degrades ou...

Ramos, A Asensio

2011-01-01T23:59:59.000Z

468

Handbook of solar energy data for south-facing surfaces in the United States. Volume III. Average hourly and total daily insolation data for 235 localities (North Carolina - Wyoming)  

DOE Green Energy (OSTI)

Average hourly and daily total insolation estimates are given for 235 US sites at a variety of array tilt angles. (MHR)

Smith, J.H.

1980-01-15T23:59:59.000Z

469

Use of periodic approximants in a dynamical LEED study of the quasicrystalline tenfold surface of decagonal Al-Ni-Co  

SciTech Connect

The determination of quasicrystal (QC) surface structures is a challenge to current surface structure techniques. Low-energy electron diffraction (LEED) is the primary technique for the determination of periodic surface structures, but application of dynamical LEED to quasicrystals requires the use of many approximations. In this study, two different approaches were used to apply dynamical LEED to the structure of the tenfold surface of decagonal Al{sub 73}Ni{sub 10}Co{sub 17}. One method (method 1) involves the use of a quasicrystalline model along with approximations that average over the composition and local geometries. The other method (method 2) uses periodic models that approximate the actual local QC structure (approximants) in more exact, atomistic calculations. Although the results using the two methods were consistent, the results of the approximant analysis (method 2) suggested a different way to apply the approximations in method 1, resulting in a better fit between experimental and calculated beams. Thus, periodic approximant structure models can provide a simpler and more efficient method for the determination of local geometries in QC surfaces, and may also facilitate analyses using quasicrystal models.

Pussi, K.; Ferralis, N.; Mihalkovic, M.; Widom, M.; Curtarolo, S.; Gierer, M.; Jenks, C. J.; Canfield, P.; Fisher, I. R.; Diehl, R. D. [Department of Electrical Engineering, Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland); Physics Department and Materials Research Institute, Penn State University, University Park, Pennsylvania 16802 (United States); Slovak Academy of Sciences, Dubravska Cesta 9, Bratislava 84228 (Slovakia); Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Materials Science and Mechanical Engineering, Duke University, Durham, North Carolina 27708 (United States); Institute for Crystallography and Applied Mineralogy, Theresienstrasse 41, 80333 Muenchen (Germany); Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Physics Department and Materials Research Institute, Penn State University, University Park, Pennsylvania 16802 (United States)

2006-05-01T23:59:59.000Z

470

Discretization and Approximation Methods for Reinforcement Learning of Highly Reconfigurable Systems  

E-Print Network (OSTI)

There are a number of techniques that are used to solve reinforcement learning problems, but very few that have been developed for and tested on highly reconfigurable systems cast as reinforcement learning problems. Reconfigurable systems refers to a vehicle (air, ground, or water) or collection of vehicles that can change its geometrical features, i.e. shape or formation, to perform tasks that the vehicle could not otherwise accomplish. These systems tend to be optimized for several operating conditions, and then controllers are designed to reconfigure the system from one operating condition to another. Q-learning, an unsupervised episodic learning technique that solves the reinforcement learning problem, is an attractive control methodology for reconfigurable systems. It has been successfully applied to a myriad of control problems, and there are a number of variations that were developed to avoid or alleviate some limitations in earlier version of this approach. This dissertation describes the development of three modular enhancements to the Q-learning algorithm that solve some of the unique problems that arise when working with this class of systems, such as the complex interaction of reconfigurable parameters and computationally intensive models of the systems. A multi-resolution state-space discretization method is developed that adaptively rediscretizes the state-space by progressively finer grids around one or more distinct Regions Of Interest within the state or learning space. A genetic algorithm that autonomously selects the basis functions to be used in the approximation of the action-value function is applied periodically throughout the learning process. Policy comparison is added to monitor the state of the policy encoded in the action-value function to prevent unnecessary episodes at each level of discretization. This approach is validated on several problems including an inverted pendulum, reconfigurable airfoil, and reconfigurable wing. Results show that the multi-resolution state-space discretization method reduces the number of state-action pairs, often by an order of magnitude, required to achieve a specific goal and the policy comparison prevents unnecessary episodes once the policy has converged to a usable policy. Results also show that the genetic algorithm is a promising candidate for the selection of basis functions for function approximation of the action-value function.

Lampton, Amanda K.

2009-12-01T23:59:59.000Z

471

NERSC Hopper Hours Used Report  

NLE Websites -- All DOE Office Websites (Extended Search)

72.3 04012013 3.520 95.6 03312013 3.613 98.1 03302013 3.242 88.1 03292013 3.456 93.9 03282013 3.562 96.7 03272013 3.519 95.6 03262013 3.449 93.7 03252013 3.370...

472

Material characterization of the clay bonded silicon carbide candle filters and ash formations in the W-APF system after 500 hours of hot gas filtration at AEP. Appendix to Advanced Particle Filter: Technical progress report No. 11, January--March 1993  

SciTech Connect

(1) After 500 hours of operation in the pressurized fluidized-bed combustion gas environment, the fibrous outer membrane along the clay bonded silicon carbide Schumacher Dia Schumalith candles remained intact. The fibrous outer membrane did not permit penetration of fines through the filter wall. (2) An approximate 10-15% loss of material strength occurred within the intact candle clay bonded silicon carbide matrix after 500 hours of exposure to the PFBC gas environment. A relatively uniform strength change resulted within the intact candles throughout the vessel (i.e., top to bottom plenums), as well as within the various cluster ring positions (i.e., outer versus inner ring candle filters). A somewhat higher loss of material strength, i.e., 25% was detected in fractured candle segments removed from the W-APF ash hopper. (3) Sulfur which is present in the pressurized fluidized-bed combustion gas system induced phase changes along the surface of the binder which coats the silicon carbide grains in the Schumacher Dia Schumalith candle filter matrix.

Alvin, M.A.

1993-04-05T23:59:59.000Z

473

An approximate-reasoning-based method for screening high-level waste tanks for flammable gas  

DOE Green Energy (OSTI)

The in situ retention of flammable gas produced by radiolysis and thermal decomposition in high-level waste can pose a safety problem if the gases are released episodically into the dome space of a storage tank. Screening efforts at Hanford have been directed at identifying tanks in which this situation could exist. Problems encountered in screening motivated an effort to develop an improved screening methodology. Approximate reasoning (AR) is a formalism designed to emulate the kinds of complex judgments made by subject matter experts. It uses inductive logic structures to build a sequence of forward-chaining inferences about a subject. AR models incorporate natural language expressions known as linguistic variables to represent evidence. The use of fuzzy sets to represent these variables mathematically makes it practical to evaluate quantitative and qualitative information consistently. The authors performed a pilot study to investigate the utility of AR for flammable gas screening. They found that the effort to implement such a model was acceptable and that computational requirements were reasonable. The preliminary results showed that important judgments about the validity of observational data and the predictive power of models could be made. These results give new insights into the problems observed in previous screening efforts.

Eisenhawer, S.W.; Bott, T.F.; Smith, R.E.

1998-07-01T23:59:59.000Z

474

Discrete Dipole Approximation for Low-Energy Photoelectron Emission from NaCl Nanoparticles  

SciTech Connect

This work presents a model for the photoemission of electrons from sodium chloride nanoparticles 50-500 nm in size, illuminated by vacuum ultraviolet light with energy ranging from 9.4-10.9 eV. The discrete dipole approximation is used to calculate the electromagnetic field inside the particles, from which the two-dimensional angular distribution of emitted electrons is simulated. The emission is found to favor the particle?s geometrically illuminated side, and this asymmetry is compared to previous measurements performed at the Lawrence Berkeley National Laboratory. By modeling the nanoparticles as spheres, the Berkeley group is able to semi-quantitatively account for the observed asymmetry. Here however, the particles are modeled as cubes, which is closer to their actual shape, and the interaction of an emitted electron with the particle surface is also considered. The end result shows that the emission asymmetry for these low-energy electrons is more sensitive to the particle-surface interaction than to the specific particle shape, i.e., a sphere or cube.

Berg, Matthew J.; Wilson, Kevin R.; Sorensen, Chris; Chakrabarti, Amit; Ahmed, Musahid

2011-09-22T23:59:59.000Z

475

Born-Oppenheimer-type Approximations for Degenerate Potentials: Recent Results and a Survey on the area  

E-Print Network (OSTI)

This paper is devoted to the asymptotics of eigenvalues for a Schr\\"o-dinger operator in the case when the potential V does not tend to infinity at infinity. Such a potential is called degenerate. The point is that the set in the phase space where the associated hamiltonian is smaller than a fixed energy E may have an infinite volume, so that the Weyl formula which gives the behaviour of the counting function has to be revisited. We recall various results in this area, in the classical context as well as in the semi-classical one and comment the different methods. In sections 3, 4 we present our joint works with A Morame, (Universit\\'e de Nantes),concerning a degenerate potential V(x) =f(y) g(z), where g is assumed to be a homogeneous positive function of m variables, and f is a smooth and strictly positive function of n variables, with a minimum in 0. In the case where f tends to infinity at infinity, we give the semi-classical asymptotic behaviour of the number of eigenvalues less than a fixed energy . Then we give a sharp estimate of the low eigenvalues, using a Born Oppenheimer approximation. With a refined approach we localize also higher energies . Finally we apply the previous methods to a class of potentials which vanish on a regular hypersurface.

Francoise Truc

2009-01-05T23:59:59.000Z

476

Prioritizing the purchase of spare parts using an approximate reasoning models.  

SciTech Connect

The complexity of a spare parts prioritization model should be consonant with the amount and quality of data available to populate it. When production processes are new and the reliability database is sparse and represents primarily expert knowledge, an approximate reasoning (AR) based model is appropriate. AR models are designed to emulate the inferential processes used by experts in making judgments. We have designed and tested such a model for the planned component production process for nuclear weapons at Los Alamos National Laboratory. The model successfully represents the experts knowledge concerning the frequency and consequences of a part failure. The use of linguistic variables provides an adaptable format for eliciting this knowledge and providing a consistent brisis for valuing the effect on production of different parts. Ranking the parts for inclusion in a spare parts inventory is a straightforward transformation of the AR output. The basis for this ranking is directly traceable to the elicitation results. AR-based models are well-suited to prioritization problems with these characteristics.

Eisenhawer, S. W. (Stephen W.); Bott, T. F. (Terrence F.); Jackson, J. W. (Joseph W.)

2001-01-01T23:59:59.000Z

477

Strong-field approximation for ionization of a diatomic molecule by a strong laser field  

Science Conference Proceedings (OSTI)

We present a theory of ionization of diatomic molecules by a strong laser field. A diatomic molecule is considered as a three-particle system, which consists of two heavy atomic (ionic) centers and an electron. After the separation of the center-of-mass coordinate, the dynamics of this system is reduced to the relative electronic and nuclear coordinates. The exact S-matrix element for ionization is presented in a form in which the laser-molecule interaction is emphasized. This form is useful for application of the molecular strong-field approximation (SFA). We introduced two forms of the molecular SFA, one with the field-free and the other with the field-dressed initial molecular bound state. We relate these two forms of our modified molecular SFA to the standard molecular SFAs, introduced previously using the length gauge and the velocity gauge. Numerical examples of the ionization rates of N{sub 2} and O{sub 2} molecules are shown and compared for all four versions of the molecular SFA and we suggest that our modified molecular SFA should be used instead of the standard molecular SFA.

Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina and Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

2006-12-15T23:59:59.000Z

478

A correlated-polaron electronic propagator: open electronic dynamics beyond the Born-Oppenheimer approximation  

E-Print Network (OSTI)

In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing this model we have also applied the time-convolutionless perturbation theory to correlated molecular excitations for the first time. Resonant response properties are given by the formalism without phenomenological parameters. Example propagations with a developmental code are given demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system.

John A. Parkhill; Thomas Markovich; David G. Tempel; Alan Aspuru-Guzik

2012-06-12T23:59:59.000Z

479

A correlated-polaron electronic propagator: open electronic dynamics beyond the Born-Oppenheimer approximation  

E-Print Network (OSTI)

In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing th...

Parkhill, John A; Tempel, David G; Aspuru-Guzik, Alan

2012-01-01T23:59:59.000Z

480

Existence of Ground State of an Electron in the BDF Approximation  

E-Print Network (OSTI)

The Bogoliubov-Dirac-Fock (BDF) model allows to describe relativistic elec- trons interacting with the Dirac sea. It can be seen as a mean-field approximation of Quantum Electro-dynamics (QED) where photons are neglected. This paper treats the case of an electron together with the Dirac sea in absence of any external field. Such a system is described by its one-body density matrix, an infinite rank, self-adjoint operator which is a compact pertubation of the negative spectral projector of the free Dirac operator. We prove the existence of minimizers of the BDF-energy under the charge constraint of one electron assuming that the coupling constant {\\alpha} and the quantity L = \\alpha log(\\Lambda) are small where \\Lambda > 0 is the ultraviolet cut-off and chosen very large. We then study the non-relativistic limit of such a system in which the speed of light c tends to infinity (or equivalently \\alpha tends to zero) with L fixed: after rescaling the electronic solution tends to the Choquard-Pekar ground state.

Jérémy Sok

2012-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "approximately one-half hour" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Beyond the born approximation: Measuring the two-photon exchange effect at CLAS  

Science Conference Proceedings (OSTI)

Recent results from experiments at Jefferson Laboratory, Newport News VA, which measured the ratio of the electric to magnetic form factors of the proton, G{sub E}/G{sub M}, have forced us to reexamine the single photon exchange approximation in lepton-proton elastic scattering. Discrepancies between the ratio obtained via the time-tested Rosenbluth separation method and newer polarization transfer measurements, which differ by as much as a factor of three, may be resolved by considering the effect of two photon exchange (TPE) processes. The CLAS TPE experiment at Jefferson Laboratory, will determine the effect of two-photon exchange in elastic lepton-proton scattering by precisely measuring the ratio of positron-proton to electron-proton elastic cross sections over a large kinematic range (0.1 CEBAF), onto a set of radiators and converters to produce simultaneous and identical beams of electron and positrons which collide with our proton target. Acceptance and efficiency concerns are minimized by only considering the ratios of the elastic cross sections and by switching polarity of magnets in the beamline and the spectrometer. Guided by the results of a short 2006 test run and extensive GEANT based modeling, new shielding and beamline components were designed to maximize luminosity. We took data from November 2010 - February 2011. The unique experimental design and challenges of the TPE experiment and the current analysis status will be presented.

Robert Paul Bennett

2012-04-01T23:59:59.000Z

482

Skyrme random-phase-approximation description of spin-flip M1 giant resonance  

SciTech Connect

The spin-flip M1 giant resonance is explored in the framework of the random-phase-approximation (RPA) on the basis of the Skyrme energy functional. A representative set of eight Skyrme parametrizations (SkT6, SkM*, SLy6, SG2, SkO, SkO', SkI4, and SV-bas) is used. Light and heavy, spherical and deformed nuclei ({sup 48}Ca, {sup 158}Gd, {sup 208}Pb, and {sup 238}U) are considered. The calculations show that spin densities play a crucial role in forming the collective shift in the spectrum. The interplay of the collective shift and spin-orbit splitting determines the quality of the description. None of the considered Skyrme parametrizations is able to describe simultaneously the M1 strength distribution in closed-shell and open-shell nuclei. It is found that the problem lies in the relative positions of proton and neutron spin-orbit splitting. This calls for a better modeling of the tensor and isovector spin-orbit interaction.

Vesely, P.; Kvasil, J. [Institute of Particle and Nuclear Physics, Charles University, CZ-18000, Praha 8 (Czech Republic); Nesterenko, V. O. [Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Moscow region, RU-141980 (Russian Federation); Kleinig, W. [Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Moscow region, RU-141980 (Russian Federation); Technische Universitaet Dresden, Inst. fuer Analysis, D-0106 Dresden (Germany); Reinhard, P.-G. [Institut fuer Theoretische Physik II, Universitaet Erlangen, D-91058 Erlangen (Germany); Ponomarev, V. Yu. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)

2009-09-15T23:59:59.000Z

483

BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION  

SciTech Connect

The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for diagnosing magnetic fields in the solar and stellar atmospheres. A fully Bayesian approach to the inference of magnetic properties in unresolved structures is presented. The analytical expression for the marginal posterior distribution is obtained, from which we can obtain statistically relevant information about the model parameters. The role of a priori information is discussed and a hierarchical procedure is presented that gives robust results that are almost insensitive to the precise election of the prior. The strength of the formalism is demonstrated through an application to IMaX data. Bayesian methods can optimally exploit data from filter polarimeters given the scarcity of spectral information as compared with spectro-polarimeters. The effect of noise and how it degrades our ability to extract information from the Stokes profiles is analyzed in detail.

Asensio Ramos, A., E-mail: aasensio@iac.es [Instituto de Astrofisica de Canarias, 38205, La Laguna, Tenerife (Spain); Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain)

2011-04-10T23:59:59.000Z

484

Radioactive waste management integrated data base: a bibliography. [Approximately 1100 references  

Science Conference Proceedings (OSTI)

The purpose of this indexed bibliography is to organize and collect the literature references on waste generation and treatment, characteristics, inventories, and costs. The references were captured into a searchable information file, and the information file was sorted, indexed, and printed for this bibliography. A completion of approximately 1100 references to nuclear waste management, the first of a series, is completed. Each reference is categorized by waste origin (commercial, defense, institutional, and foreign) and by subject area: (1) high-level wastes, (2) low-level wastes, (3) TRU wastes, (4) airborne wastes, (5) remedial action (formerly utilized sites, surplus facilities, and mill tailings), (6) isolation, (7) transportation, (8) spent fuel, (9) fuel cycle centers, and (10) a general category that covers nonspecific wastes. Five indexes are provided to assist the user in locating documents of interest: author, author affiliation (corporate authority), subject category, keyword, and permuted title. Machine (computer) searches of these indexes can be made specifying multiple constraints if so desired. This bibliography will be periodically updated as new information becomes available. In addition to being used in searches for specific data, the information file can also be used for resource document collection, names and addresses of contacts, and identification of potential sources of data.

Johnson, C.A.; Garland, P.A.

1980-09-01T23:59:59.000Z

485

BILAM: a composite laminate failure-analysis code using bilinear stress-strain approximations  

DOE Green Energy (OSTI)

The BILAM code which uses constant strain laminate analysis to generate in-plane load/deformation or stress/strain history of composite laminates to the point of laminate failure is described. The program uses bilinear stress-strain curves to model layer stress-strain behavior. Composite laminates are used for flywheels. The use of this computer code will help to develop data on the behavior of fiber composite materials which can be used by flywheel designers. In this program the stress-strain curves are modelled by assuming linear response in axial tension while using bilinear approximations (2 linear segments) for stress-strain response to axial compressive, transverse tensile, transverse compressive and axial shear loadings. It should be noted that the program attempts to empirically simulate the effects of the phenomena which cause nonlinear stress-strain behavior, instead of mathematically modelling the micromechanics involved. This code, therefore, performs a bilinear laminate analysis, and, in conjunction with several user-defined failure interaction criteria, is designed to provide sequential information on all layer failures up to and including the first fiber failure. The modus operandi is described. Code BILAM can be used to: predict the load-deformation/stress-strain behavior of a composite laminate subjected to a given combination of in-plane loads, and make analytical predictions of laminate strength.

McLaughlin, P.V. Jr.; Dasgupta, A.; Chun, Y.W.

1980-10-01T23:59:59.000Z

486

Coarse-Graining Can Beat the Rotating Wave Approximation in Quantum Markovian Master Equations  

E-Print Network (OSTI)

We present a first-principles derivation of the Markovian semi-group master equation without invoking the rotating wave approximation (RWA). Instead we use a time coarse-graining approach which leaves us with a free timescale parameter, which we can optimize. Comparing this approach to the standard RWA-based Markovian master equation, we find that significantly better agreement is possible using the coarse-graining approach, for a three-level model coupled to a bath of oscillators, whose exact dynamics we can solve for at zero temperature. The model has the important feature that the RWA has a non-trivial effect on the dynamics of the populations. We show that the two different master equations can exhibit strong qualitative differences for the population of the energy eigenstates even for such a simple model. The RWA-based master equation misses an important feature which the coarse-graining based scheme does not. By optimizing the coarse-graining timescale the latter scheme can be made to approach the exact solution much more closely than the RWA-based master equation.

Christian Majenz; Tameem Albash; Heinz-Peter Breuer; Daniel A. Lidar

2013-03-26T23:59:59.000Z

487

Regional load-curve models: QUERI's model long-run forecasts and sensitivity analysis. Volume 4. Final report. [Hourly demand in 32 US regions  

SciTech Connect

This report presents detailed forecasts of the hourly demand for electricity in 32 regions of the US through the year 2000. The forecasts are generated by a load curve model estimated by QUERI and described in Volume II of this report. Two primary sets of input assumptions for this model are utilized: one based on DRI's macro, regional and sectoral models is called the Baseline Scenario while the other, which is a projection of historical trends, is the Extrapolation Scenario. Under both assumptions, the growth rates of electricity are forecast to slow from historical levels. Load factors are generally projected to continue to decline; most regions are forecast to remain Summer peaking but this is rather sensitive to the choice of scenario. By considering other scenarios which are small perturbations of the Baseline assumptions, elasticities of average, peak and hourly loads are calculated. Different weather assumptions are also examined for the sensitivity of the load shapes to changes in the weather.

Engle, R.F.; Granger, C.W.J.; Ramanathan, R.

1981-09-01T23:59:59.000Z

488

Alterations of the Climate of a Primitive Equation Model produced by Filtering Approximations and Subsequent Tuning and Stochastic Forcing  

Science Conference Proceedings (OSTI)

The simulated climates of highly truncated nonlinear models based on the primitive equations (PE), balance equations (BE) and quasi-geostrophic (QG) equations are compared, in order to determine the effects of the filtering approximations. The ...

Ross N. Hoffman

1981-03-01T23:59:59.000Z

489

Two-Stream Approximations to Radiative Transfer in Planetary Atmospheres: A Unified Description of Existing Methods and a New Improvement  

Science Conference Proceedings (OSTI)

Existing two-stream approximations to radiative transfer theory for particulate media are shown to be represented by identical forms of coupled differential equations if the intensity is replaced by integrals of the intensity over hemispheres. ...

W. E. Meador; W. R. Weaver

1980-03-01T23:59:59.000Z

490

Implementing the Delta-Four-Stream Approximation for Solar Radiation Computations in an Atmosphere General Circulation Model  

Science Conference Proceedings (OSTI)

Proper quantification of the solar radiation budget and its transfer within the atmosphere is of utmost importance in climate modeling. The delta-four-stream (DFS) approximation has been demonstrated to offer a more accurate computational method ...

Tarek Ayash; Sunling Gong; Charles Q. Jia

2008-07-01T23:59:59.000Z

491

Evaluation of Various Approximations in Atmosphere and Ocean Modeling based on an Exact Treatment of Gravity Wave Dispersion  

Science Conference Proceedings (OSTI)

Various approximations of the governing equations of compressible fluid dynamics are commonly used in both atmospheric and ocean modeling. Their main purpose is to eliminate the acoustic waves that are potentially responsible for inefficiency in ...

John K. Dukowicz

492

Analytical Solutions to the Collection Growth Equation: Comparison with Approximate Methods and Application to Cloud Microphysics Parameterization Schemes  

Science Conference Proceedings (OSTI)

A closed form solution for the collection growth equation as used in bulk microphysical parameterizations is derived. Although the general form is mathematically complex, it can serve as a benchmark for testing a variety of approximations. Two ...

Johannes Verlinde; Piotr J. Flatau; William R. Cotton

1990-12-01T23:59:59.000Z

493

Approximation of Ocean Heat Storage by Ocean–Atmosphere Energy Exchange: Implications for Seasonal Cycle Mixed Layer Ocean Formulations  

Science Conference Proceedings (OSTI)

The approximation of ocean heat storage by the net surface energy flux and the implications for zonal mean SST simulation using mixed layer ocean formulation are examined. The analysis considers both constant and variable depth mixed layers. ...

Robert G. Gallimore; David D. Houghton

1987-08-01T23:59:59.000Z

494

Methods, systems and apparatus for approximation of peak summed fundamental and third harmonic voltages in a multi-phase machine  

DOE Patents (OSTI)

Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.

Ransom, Ray M. (Big Bear City, CA); Gallegos-Lopez, Gabriel (Torrance, CA); Kinoshita, Michael H. (Redondo Beach, CA)

2012-07-31T23:59:59.000Z

495

Redundant operators in the exact renormalisation group and in the f(R) approximation to asymptotic safety  

E-Print Network (OSTI)

In this paper we review the definition and properties of redundant operators in the exact renormalisation group. We explain why it is important to require them to be eigenoperators and why generically they appear only as a consequence of symmetries of the particular choice of renormalisation group equations. This clarifies when Newton's constant and or the cosmological constant can be considered inessential. We then apply these ideas to the Local Potential Approximation and approximations of a similar spirit such as the f(R) approximation in the asymptotic safety programme in quantum gravity. We show that these approximations can break down if the fixed point does not support a `vacuum' solution in the appropriate domain: all eigenoperators become redundant and the physical space of perturbations collapses to a point. We show that this is the case for the recently discovered lines of fixed points in the f(R) flow equations.

Juergen A. Dietz; Tim R. Morris

2013-06-05T23:59:59.000Z

496

Improved Normalization of the Size Distribution of Atmospheric Particles Retrieved from Aureole Measurements Using the Diffraction Approximation  

Science Conference Proceedings (OSTI)

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the ...

J. G. DeVore

2011-08-01T23:59:59.000Z

497

An Approximate Dynamic Programming Approach to Benchmark Practice-based Heuristics for Natural Gas Storage Valuation  

E-Print Network (OSTI)

The valuation of the real option to store natural gas is a practically important problem that entails dynamic optimization of inventory trading decisions with capacity constraints in the face of uncertain natural gas price dynamics. Stochastic dynamic programming is a natural approach to this valuation problem, but it does not seem to be widely used in practice because it is at odds with the high-dimensional naturalgas price evolution models that are widespread among traders. According to the practice-based literature, practitioners typically value natural gas storage heuristically. The effectiveness of the heuristics discussed in this literature is currently unknown, because good upper bounds on the value of storage are not available. We develop a novel and tractable approximate dynamic programming method that coupled with Monte Carlo simulation computes lower and upper bounds on the value of storage, which we use to benchmark these heuristics on a set of realistic instances. We find that these heuristics are extremely fast but significantly suboptimal as compared to our upper bound, which appears to be fairly tight and much tighter than a simpler perfect information upper bound; our lower bound is slower to compute than these heuristics but substantially outperforms them in terms of valuation. Moreover, with periodic reoptimizations embedded in Monte Carlo simulation, the practice-based heuristics become nearly optimal, with one exception, at the expense of higher computational effort. Our lower bound with reoptimization is also nearly optimal, but exhibits a higher computational requirement than these heuristics. Besides natural gas storage, our results are potentially relevant for the