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1

Assessing the reliability of linear dynamic transformer thermal modelling  

E-Print Network (OSTI)

Assessing the reliability of linear dynamic transformer thermal modelling X. Mao, D.J. Tylavsky and G.A. McCulla Abstract: Improving the utilisation of transformers requires that the hot-spot and top. An alternative method for assessing transformer model reliability is provided. 1 Introduction The maximally

2

Dynamically Coupled 3D Pollutant Dispersion Model for Assessing Produced Water Discharges in the Canadian Offshore Area  

Science Journals Connector (OSTI)

Dynamically Coupled 3D Pollutant Dispersion Model for Assessing Produced Water Discharges in the Canadian Offshore Area ... The collected samples of produced water and seawater were analyzed by the COOGER (Centre for Offshore Oil and Gas Environmental Research) at the Fisheries and Oceans Canada, Environmental Engineering labrotary at the Concordia University, and the Trace Analysis Facility (TAF) at the University of Regina. ... In Offshore Oil and Gas Environmental Effects Monitoring Approaches and Technologies; Armsworthy, S. L.; Cranford, P. J.; Lee, K., Eds.; Battelle Memorial Institute: Columbus, OH 2005; pp 319– 342. ...

Lin Zhao; Zhi Chen; Kenneth Lee

2012-12-26T23:59:59.000Z

3

Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application to Weapon Systems  

E-Print Network (OSTI)

to Weapon Systems Maxime Monnin, LAMIH, University of Valenciennes Benoit Iung, PhD, CRAN, Nancy University of unavailability. Military weapon systems can become unavailable due to system failures or damage to the system. This paper aims to define principles for weapon systems modeling that integrate both system failure

Paris-Sud XI, Université de

4

AVESTAR® - Dynamic Modeling  

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

Dynamic Modeling Dynamic Modeling The AVESTAR team is pursuing research on the dynamic modeling and simulation of advanced energy systems ranging from power plants to power grids. Dynamic models provide a continuous view of energy systems in action by calculating their transient behavior over time. Plant-wide Models For power plants, dynamic models are used to analyze a wide variety of operating scenarios, including normal base load operation, startup, shutdown, feedstock switchovers, cycling, and load-following. Dynamic process and control models are also essential for analyzing plant responses to setpoint changes and disturbances, as well as malfunctions and abnormal situations. Other applications of plant-wide dynamic models include controllability and operational flexibility analyses, environmental studies, safety evaluations, and risk mitigation.

5

Models of Dynamical Supersymmetry Breaking  

E-Print Network (OSTI)

We review a class of models of dynamical supersymmetry breaking, and give a unified description of these models.

Lisa Randall

1997-06-23T23:59:59.000Z

6

Dynamic Modelling, Measurement and  

E-Print Network (OSTI)

Dynamic Modelling, Measurement and Control of Co-rotating Twin-Screw Extruders Justin Rae Elsey, B;Summary Co-rotating twin-screw extruders are unique and versatile machines that are used widely that these extruders are currently being optimally utilised. The most signi cant improvement to the eld of twin-screw

Fernandez, Thomas

7

Regional Dynamics Model (REDYN) | Open Energy Information  

Open Energy Info (EERE)

Regional Dynamics Model (REDYN) Regional Dynamics Model (REDYN) Jump to: navigation, search Tool Summary Name: REDYN Agency/Company /Organization: Regional Dynamics Inc. Sector: Energy Phase: Determine Baseline, "Evaluate Options and Determine Feasibility" is not in the list of possible values (Bring the Right People Together, Create a Vision, Determine Baseline, Evaluate Options, Develop Goals, Prepare a Plan, Get Feedback, Develop Finance and Implement Projects, Create Early Successes, Evaluate Effectiveness and Revise as Needed) for this property., Develop Goals Topics: Market analysis, Policies/deployment programs, Co-benefits assessment, - Macroeconomic Resource Type: Software/modeling tools User Interface: Desktop Application Website: www.regionaldynamics.com/

8

Dynamic safeguard assessment of terror attacks using system dynamics method for nuclear power plants  

Science Journals Connector (OSTI)

For the minimisation of the damage in possible terror attacks on the nuclear power plants and other nuclear facilities, a dynamic assessment is performed in the aspects of nuclear safeguard. The incidents against nuclear facilities are modelled by the time-step scenario. Several cases are explained for the illicit trafficking of radioactive material. The dynamic simulation is examined by the system dynamics method. In the modelling, there are three major models that include the nuclear insider terror, the reaction control and the nuclear forensic steps. The risk increases slowly and decreases rapidly in the result. This is the similar pattern of the September 2001 terror where many lives were lost.

Tae-Ho Woo; Un-Chul Lee; Yun-Il Kim

2010-01-01T23:59:59.000Z

9

ORISE: Dose modeling and assessments  

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

have participated include: Derivation of DCGLs for the Curtis Bay and Hammond depots Vermont Yankee Nuclear Power Station dose assessment study Radium timepiece dose modeling...

10

Environmental Design Space model assessment  

E-Print Network (OSTI)

The Environmental Design Space (EDS) is a multi-disciplinary design tool used to explore trade-offs among aircraft fuel burn, emissions, and noise. This thesis uses multiple metrics to assess an EDS model of a Boeing 777 ...

Spindler, Phillip Michael

2007-01-01T23:59:59.000Z

11

Dynamical safety assessment of hydrogen production nuclear power plants using system dynamics method  

Science Journals Connector (OSTI)

Nuclear power plants for hydrogen production are investigated in the aspect of nuclear safety. The non-linear dynamical safety assessment is introduced for the analysis of the high temperature gas cooled reactor (HTGR) which is used for hydrogen production as well as electricity generation. The dynamical algorithm is adjusted for the safety assessment with an easier and reliable output. A feedback of power increase affects to the temperature decrease. The top event of the event is power and temperature stable. It is affected by the human factor, poison, and some other physical variables. There are several factors including the economic and safety factors which are considered for the reliability of the modelling simulations. Using the system dynamics (SD) method, the event quantification is performed for the event flows, stocks, and feedback by the single and double arrow lines.

Taeho Woo; Soonho Lee

2013-01-01T23:59:59.000Z

12

Modeling emotional dynamics : currency versus field.  

SciTech Connect

Randall Collins has introduced a simplified model of emotional dynamics in which emotional energy, heightened and focused by interaction rituals, serves as a common denominator for social exchange: a generic form of currency, except that it is active in a far broader range of social transactions. While the scope of this theory is attractive, the specifics of the model remain unconvincing. After a critical assessment of the currency theory of emotion, a field model of emotion is introduced that adds expressiveness by locating emotional valence within its cognitive context, thereby creating an integrated orientation field. The result is a model which claims less in the way of motivational specificity, but is more satisfactory in modeling the dynamic interaction between cognitive and emotional orientations at both individual and social levels.

Sallach, D .L.; Decision and Information Sciences; Univ. of Chicago

2008-08-01T23:59:59.000Z

13

Predictive Models of Forest Dynamics  

Science Journals Connector (OSTI)

...currently highly uncertain (Fig. 1), making vegetation dynamics one of the largest sources of uncertainty in Earth system models. Reducing this uncertainty requires work on several fronts. For example, physiological parameters need to be...

Drew Purves; Stephen Pacala

2008-06-13T23:59:59.000Z

14

Model system for slow dynamics  

Science Journals Connector (OSTI)

Systems whose dynamics are described by a quasilogarithmic or stretched-exponential time dependence are usually fitted by models which use disorder to create a distribution of relaxation times. Here we describe a model which decays slowly towards equilibrium but does not require disorder to provide the slow dynamics. The model consists of a spin system with the spins interacting via the dipole-dipole interaction. The model is able to replicate the more pronounced features observed in the magnetization decay of magnetic systems and high-temperature superconductors.

D. K. Lottis; R. M. White; E. Dan Dahlberg

1991-07-15T23:59:59.000Z

15

DYNAMIC MODELING FUEL PROCESSORS  

E-Print Network (OSTI)

for reusability, rapid development and assessment of complete system, and design improvement from simulation results BACKGROUND · Fuel cell based power systems are becoming increasingly important in aeronautical applications · Reformer based fuel cell systems make the technology amenable to logistic fuels such as diesel

Mease, Kenneth D.

16

Modeling Molecular Dynamics from Simulations  

SciTech Connect

Many important processes in biology occur at the molecular scale. A detailed understanding of these processes can lead to significant advances in the medical and life sciences. For example, many diseases are caused by protein aggregation or misfolding. One approach to studying these systems is to use physically-based computational simulations to model the interactions and movement of the molecules. While molecular simulations are computationally expensive, it is now possible to simulate many independent molecular dynamics trajectories in a parallel fashion by using super- or distributed- computing methods such as Folding@Home or Blue Gene. The analysis of these large, high-dimensional data sets presents new computational challenges. In this seminar, I will discuss a novel approach to analyzing large ensembles of molecular dynamics trajectories to generate a compact model of the dynamics. This model groups conformations into discrete states and describes the dynamics as Markovian, or history-independent, transitions between the states. I will discuss why the Markovian state model (MSM) is suitable for macromolecular dynamics, and how it can be used to answer many interesting and relevant questions about the molecular system. I will also discuss many of the computational and statistical challenges in building such a model, such as how to appropriately cluster conformations, determine the statistical reliability, and efficiently design new simulations.

Hinrichs, Nina Singhal (University of Chicago) [University of Chicago

2009-01-28T23:59:59.000Z

17

Development of a Dynamic DOE Calibration Model  

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

A dynamic heavy duty diesel engine model was developed. The model can be applied for calibration and control system optimization.

18

TEPP Planning Products Model Needs Assessment Self Assessment Document  

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

Planning Products Planning Products Model Needs Assessment Self Assessment Document Prepared for the Department of Energy Office of Transportation and Emergency Management 02B00215-13.p65 1 Model Needs Assessment R E V 8 - 0 7 / 2 0 1 2 T r a n s p o r t a t i o n E m e r g e n c y P r e p a r e d n e s s P r o g r a m PURPOSE The purpose of this Model Needs Assessment is to assist state, tribal, or local officials in determining emergency responder readiness for response to a transportation accident involving radioactive material. 1.0 INTRODUCTION This Model Needs Assessment was developed by the Department of Energy's Transportation Emergency Preparedness Program (TEPP) as a planning and assessment tool for state, tribal, or local government officials. To implement this Model Needs Assessment, a designated official

19

SYSTEM DYNAMICS USE FOR TECHNOLOGIES ASSESSMENT Egils Ginters (a)  

E-Print Network (OSTI)

, and existence of concurrent technologies for sustainability assessment. Keywords: technology assessment, system and sustainability of the new technology in real time. In the framework of FP7-ICT- 2009-5 CHOREOS project No. 257178SYSTEM DYNAMICS USE FOR TECHNOLOGIES ASSESSMENT Egils Ginters (a) , Zane Barkane (b) , Hugues

Boyer, Edmond

20

Dynamical model of Ising spins  

Science Journals Connector (OSTI)

A two-dimensional dynamical model of Ising spins is introduced. Since we were not able to define energy in our system, we introduced an object called the disagreement function. This function controls the dynamics—minimizing it locally we decide upon spin flipping. Amazingly, local minimization of the disagreement function can lead to an increase of its global value. We present the phase diagram of the system and show that exactly the same initial conditions can lead the system to one of several, completely different final steady states.

Katarzyna Sznajd-Weron

2004-09-30T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Trends in Ln(III) Sorption to Quartz Assessed by Molecular Dynamics...  

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

Ln(III) Sorption to Quartz Assessed by Molecular Dynamics Simulations and Laser Induced Flourescence Studies. Trends in Ln(III) Sorption to Quartz Assessed by Molecular Dynamics...

22

Model Fire Protection Assessment Guide  

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

This Assessment guide covers the implementation of the DOE's responsibility of assuring that DOE and the DOE Contractors have established Fire Protection Programs that are at the level required for the area being assessed.

23

Interest of the Theory of Uncertain in the Dynamic LCA- Fire Methodology to Assess Fire Effects  

Science Journals Connector (OSTI)

Abstract Life Cycle Impact Assessment (LCIA) is the third phase of Life Cycle Assessment (LCA) described in ISO 14042. The purpose of LCIA is to assess a product system's life cycle inventory analysis (LCI) in order to better understand its environmental significance. However, LCIA typically excludes spatial, temporal, threshold and dose-response information, and combines emissions or activities over space and/or time. This may diminish the environmental relevance of the indicator result. The methodology, Dynamic LCA -Fire proposed in this paper to complete the International Standard ISO 14042 in the fire field, combines the LCA - Fire method with the Dispersion Numerical Model. It is based on the use of the plume model used to assess pollutant concentrations and thermal effects from fire accident scenarios. In this study, The Dynamic LCA - Fire methodology is applied to a case study for petroleum production process management.

Samia Chettouh; Rachida Hamzi; Fares Innal; Djamel Haddad

2014-01-01T23:59:59.000Z

24

Dynamics of Nucleation in the Ising Model  

Science Journals Connector (OSTI)

Dynamics of Nucleation in the Ising Model† ... Reactive pathways to nucleation in a three-dimensional Ising model at 60% of the critical temperature are studied using transition path sampling of single spin flip Monte Carlo dynamics. ... The application focuses on the simplest example of nucleation, that of a supercooled Ising model. ...

Albert C. Pan; David Chandler

2004-09-28T23:59:59.000Z

25

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements  

E-Print Network (OSTI)

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, respectively--together predicted 94 % of the observed variability in measured total mercury concentra- tion

Boss, Emmanuel S.

26

DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.  

E-Print Network (OSTI)

(thermal, gas, diesel) and renewable (hydro, wind) power units. The objective is to assess the impact - that have a special dynamic behaviour, and the wind turbines. Detailed models for each one of the power system components are developed. Emphasis is given in the representation of different hydro power plant

Paris-Sud XI, Université de

27

Dynamic control of DHM for ergonomic assessments Giovanni De Magistrisa,  

E-Print Network (OSTI)

Dynamic control of DHM for ergonomic assessments Giovanni De Magistrisa, , Alain Micaellia , Paul hamper movement task per- formance. In recent years, it has become possible to study the ergonomic ergonomic aspects, especially when it comes to movement, applied forces and joint torques evaluation

Boyer, Edmond

28

Dynamic competition model for construction contractors  

E-Print Network (OSTI)

competition, a system dynamics model has been developed based on the identified concepts. In this model, there are three managerial areas in which a contractor makes policy: 1) markup; 2) marketing; and 3) capacity. Each firm's backlog level is considered...

Kim, Hyung Jin

2012-06-07T23:59:59.000Z

29

Conceptual aircraft dynamics from inverse aircraft modeling  

E-Print Network (OSTI)

This thesis presents a method of construe' ting a nonlinear dynamics model of a theoretical aircraft from the nonlinear batch simulation of an existing aircrew This method provides control law designers with a method of fabricating nonlinear models...

Ziegler, Gregory E

1999-01-01T23:59:59.000Z

30

A Dynamic Model of Thundercloud Electric Fields  

Science Journals Connector (OSTI)

A dynamic interactive computer model of the electrical behavior of a thundercloud surrounded by the distributed atmosphere, earth, ionosphere circuit is described. The electrification mechanisms in the model are represented by current or voltage ...

John S. Nisbet

1983-12-01T23:59:59.000Z

31

A Robust Model Control for Dynamic Systems  

Science Journals Connector (OSTI)

Analytical methods of polynomial algebra, heuristic techniques, and digital modeling are used to study the robustness domain of linear dynamic systems with model “input–output” controllers as a function of the mutual locations of zeros ...

S. V. Tararykin; V. V. Tyutikov

2002-05-01T23:59:59.000Z

32

Dynamic LES Modeling of a Diurnal Cycle  

Science Journals Connector (OSTI)

The diurnally varying atmospheric boundary layer observed during the Wangara (Australia) case study is simulated using the recently proposed locally averaged scale-dependent dynamic subgrid-scale (SGS) model. This tuning-free SGS model enables ...

Sukanta Basu; Jean-François Vinuesa; Andrew Swift

2008-04-01T23:59:59.000Z

33

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect

Abstract—Model validation has been one of the central topics in power engineering studies for years. As model validation aims at obtaining reasonable models to represent actual behavior of power system components, it has been essential to validate models against actual measurements or known benchmark behavior. System-wide model simulation results can be compared with actual recordings. However, it is difficult to construct a simulation case for a large power system such as the WECC system and to narrow down to problematic models in a large system. Hybrid dynamic simulation with its capability of injecting external signals into dynamic simulation enables rigorous comparison of measurements and simulation in a small subsystem of interest. This paper presents such a model validation methodology with hybrid dynamic simulation. Two application examples on generator and load model validation are presented to show the validity of this model validation methodology. This methodology is further extended for automatic model validation and dichotomous subsystem model validation.

Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.

2006-06-18T23:59:59.000Z

34

Interoperability between a dynamic reliability modeling and a Systems Engineering process Principles and Case Study  

E-Print Network (OSTI)

element for interoperability with the tools and activities required for a dynamic reliability assessment. The case study is the dynamic assessment of availability of a feed-water control system in a power plant steam generator, presented in previous articles. Keywords: Systems engineering, systems modeling, RAMS

Paris-Sud XI, Université de

35

Calcium Dynamics in Large Neuronal Models  

E-Print Network (OSTI)

Chapter 6 Calcium Dynamics in Large Neuronal Models ERIK DE SCHUTTER and PAUL SMOLEN 6.1 Introduction Calcium is an important intracellular signaling molecule with rapid e ect on the kinetics of many active membrane model that includes Ca2+ dynamics, one is faced with a feedback loop: the Ca2+-activated

De Schutter, Erik

36

A Dynamic Waste Isolation Pilot Plant Performance Assessment Tool - 12490  

SciTech Connect

The Waste Isolation Pilot Plant (WIPP) Performance Assessment (PA) methodology comprises a toolbox used to demonstrate regulatory compliance of the repository after facility closure. The PA framework rests upon an extensive suite of computational codes. In some cases, significant alteration of code inputs is a tedious and difficult task. Due to the nature of the application for which they are used, PA codes used in support of WIPP regulatory compliance demonstration must satisfy stringent quality assurance requirements. Consequently, many of the coding practices used during original code development are still implemented today. A more efficient workflow configuration has the potential to alleviate difficulties associated with extensive code input modifications. Here, this potential is assessed via an implementation of a more flexible scientific workflow system for a subset of the codes used in WIPP PA. The scientific workflow approach taken here for a dynamic PA system enables users from disparate backgrounds to dramatically shorten the time between hypothesis and analysis by decreasing the amount of a priori knowledge, from a range of disciplines, needed to execute the code. Having smaller iteration times allows for more ideas to be tested and explored, which leads to safer and more optimized systems. Note that these high-level, dynamic tools are intended only for initial scoping studies on the personal computer of a researcher. Full, regulatory compliance calculations may occur only within a qualified computing environment. However, the WIPP PA tools here may guide future research and indicate regions of the analysis space that are worth further study. This next generation of PA software provides the ability to perform scoping investigations of repository performance quickly and easily, and has an accessible and useful interface to a variety of users, such as fuel cycle systems designers, domain experts such as repository modelers, and policy makers. The purview of this project allows for many opportunities for future work. Foremost among these is the desire to implement the full BRAGFLO suite within the workflow. This will entail porting or wrapping Genmesh, Matset, LHS, and ICSet within Python. Moreover, unifying the two GUIs into a single driver application would be a natural next step. Once the BRAGFLO suite is completed, other portions of WIPP PA could be implemented with corresponding and inter-operable work-flows. Likely first candidates for this are those codes that are similarly computationally intensive, such as the one used to generate complementary cumulative distribution functions used to demonstrate regulatory compliance (code CCDFGF). (authors)

Scopatz, Anthony M.; March, Jonathan; Weckesser, Warren; Jones, Eric [Enthought Inc, Austin, Texas, 78701 (United States); Lee, Moo; Camphouse, Chris [Sandia National Laboratories, Carlsbad, NM, 88220 (United States)

2012-07-01T23:59:59.000Z

37

ASSESSMENT OF ECONOMIC PERFORMANCE OF MODEL PREDICTIVE  

E-Print Network (OSTI)

ASSESSMENT OF ECONOMIC PERFORMANCE OF MODEL PREDICTIVE CONTROL THROUGH VARIANCE/CONSTRAINT TUNING advanced process control (APC) strategies to deal with multivariable constrained control problems with an ultimate objective towards economic optimization. Any attempt to evaluate MPC performance should therefore

Huang, Biao

38

Very Large System Dynamics Models - Lessons Learned  

SciTech Connect

This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

Jacob J. Jacobson; Leonard Malczynski

2008-10-01T23:59:59.000Z

39

Models and parameters for environmental radiological assessments  

SciTech Connect

This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base. (ACR)

Miller, C W [ed.] [ed.

1984-01-01T23:59:59.000Z

40

Simple Dynamic Gasifier Model That Runs in Aspen Dynamics  

SciTech Connect

Gasification (or partial oxidation) is a vital component of 'clean coal' technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased, and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel for driving combustion turbines. Gasification units in a chemical plant generate gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The widely used process simulator Aspen Plus provides a library of models that can be used to develop an overall gasifier model that handles solids. So steady-state design and optimization studies of processes with gasifiers can be undertaken. This paper presents a simple approximate method for achieving the objective of having a gasifier model that can be exported into Aspen Dynamics. The basic idea is to use a high molecular weight hydrocarbon that is present in the Aspen library as a pseudofuel. This component should have the same 1:1 hydrogen-to-carbon ratio that is found in coal and biomass. For many plantwide dynamic studies, a rigorous high-fidelity dynamic model of the gasifier is not needed because its dynamics are very fast and the gasifier gas volume is a relatively small fraction of the total volume of the entire plant. The proposed approximate model captures the essential macroscale thermal, flow, composition, and pressure dynamics. This paper does not attempt to optimize the design or control of gasifiers but merely presents an idea of how to dynamically simulate coal gasification in an approximate way.

Robinson, P.J.; Luyben, W.L. [Lehigh University, Bethlehem, PA (United States). Dept. of Chemical Engineering

2008-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Analysis of Permafrost Thermal Dynamics and Response to Climate Change in the CMIP5 Earth System Models  

Science Journals Connector (OSTI)

The authors analyze global climate model predictions of soil temperature [from the Coupled Model Intercomparison Project phase 5 (CMIP5) database] to assess the models’ representation of current-climate soil thermal dynamics and their predictions ...

Charles D. Koven; William J. Riley; Alex Stern

2013-03-01T23:59:59.000Z

42

Model-based safety assessments  

SciTech Connect

Sandia National Laboratories performs systems analysis of high risk, high consequence systems. In particular, Sandia is responsible for the engineering of nuclear weapons, exclusive of the explosive physics package. In meeting this responsibility, Sandia has developed fundamental approaches to safety and a process for evaluating safety based on modeling and simulation. These approaches provide confidence in the safety of our nuclear weapons. Similar concepts may be applied to improve the safety of other high consequence systems.

Carlson, D.D.; Jones, T.R.

1998-04-01T23:59:59.000Z

43

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect

Abstract—Model validation has been one of the central topics in power engineering studies for years. As model validation aims at obtaining reasonable models to represent actual behavior of power system components, it has been essential to validate models against actual measurements or known benchmark behavior. System-wide model simulation results can be compared with actual recordings. However, it is difficult to construct a simulation case for a large power system such as the WECC system and to narrow down to problematic models in a large system. Hybrid dynamic simulation with its capability of injecting external signals into dynamic simulation enables rigorous comparison of measurements and simulation in a small subsystem of interest. This paper presents such a model validation methodology with hybrid dynamic simulation. Two application examples on generator and load model validation are presented to show the validity of this model validation methodology. This methodology is further extended for automatic model validation and dichotomous subsystem model validation. A few methods to define model quality indices have been proposed to quantify model error for model validation criteria development.

Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.

2006-06-22T23:59:59.000Z

44

Model and Analytic Processes for Export License Assessments  

SciTech Connect

This paper represents the Department of Energy Office of Nonproliferation Research and Development (NA-22) Simulations, Algorithms and Modeling (SAM) Program's first effort to identify and frame analytical methods and tools to aid export control professionals in effectively predicting proliferation intent; a complex, multi-step and multi-agency process. The report focuses on analytical modeling methodologies that alone, or combined, may improve the proliferation export control license approval process. It is a follow-up to an earlier paper describing information sources and environments related to international nuclear technology transfer. This report describes the decision criteria used to evaluate modeling techniques and tools to determine which approaches will be investigated during the final 2 years of the project. The report also details the motivation for why new modeling techniques and tools are needed. The analytical modeling methodologies will enable analysts to evaluate the information environment for relevance to detecting proliferation intent, with specific focus on assessing risks associated with transferring dual-use technologies. Dual-use technologies can be used in both weapons and commercial enterprises. A decision-framework was developed to evaluate which of the different analytical modeling methodologies would be most appropriate conditional on the uniqueness of the approach, data availability, laboratory capabilities, relevance to NA-22 and Office of Arms Control and Nonproliferation (NA-24) research needs and the impact if successful. Modeling methodologies were divided into whether they could help micro-level assessments (e.g., help improve individual license assessments) or macro-level assessment. Macro-level assessment focuses on suppliers, technology, consumers, economies, and proliferation context. Macro-level assessment technologies scored higher in the area of uniqueness because less work has been done at the macro level. An approach to developing testable hypotheses for the macro-level assessment methodologies is provided. The outcome of this works suggests that we should develop a Bayes Net for micro-level analysis and continue to focus on Bayes Net, System Dynamics and Economic Input/Output models for assessing macro-level problems. Simultaneously, we need to develop metrics for assessing intent in export control, including the risks and consequences associated with all aspects of export control.

Thompson, Sandra E.; Whitney, Paul D.; Weimar, Mark R.; Wood, Thomas W.; Daly, Don S.; Brothers, Alan J.; Sanfilippo, Antonio P.; Cook, Diane; Holder, Larry

2011-09-29T23:59:59.000Z

45

A stochastic evolutionary model for survival dynamics  

E-Print Network (OSTI)

The recent interest in human dynamics has led researchers to investigate the stochastic processes that explain human behaviour in different contexts. Here we propose a generative model to capture the essential dynamics of survival analysis, traditionally employed in clinical trials and reliability analysis in engineering. In our model, the only implicit assumption made is that the longer an actor has been in the system, the more likely it is to have failed. We derive a power-law distribution for the process and provide preliminary empirical evidence for the validity of the model from two well-known survival analysis data sets.

Fenner, Trevor; Loizou, George

2014-01-01T23:59:59.000Z

46

Modeling Internet Topology Dynamics Hamed Haddadi  

E-Print Network (OSTI)

graphs. Generation of the topology of the Internet calls for a model that achieves a good balance betweenModeling Internet Topology Dynamics Hamed Haddadi University College London Steve Uhlig Delft and inference, there still exists ambiguity about the real nature of the Internet AS and router level topol- ogy

Haddadi, Hamed

47

Dynamic modeling of IGCC power plants  

Science Journals Connector (OSTI)

Integrated Gasification Combined Cycle (IGCC) power plants are an effective option to reduce emissions and implement carbon-dioxide sequestration. The combination of a very complex fuel-processing plant and a combined cycle power station leads to challenging problems as far as dynamic operation is concerned. Dynamic performance is extremely relevant because recent developments in the electricity market push toward an ever more flexible and varying operation of power plants. A dynamic model of the entire system and models of its sub-systems are indispensable tools in order to perform computer simulations aimed at process and control design. This paper presents the development of the lumped-parameters dynamic model of an entrained-flow gasifier, with special emphasis on the modeling approach. The model is implemented into software by means of the Modelica language and validated by comparison with one set of data related to the steady operation of the gasifier of the Buggenum power station in the Netherlands. Furthermore, in order to demonstrate the potential of the proposed modeling approach and the use of simulation for control design purposes, a complete model of an exemplary IGCC power plant, including its control system, has been developed, by re-using existing models of combined cycle plant components; the results of a load dispatch ramp simulation are presented and shortly discussed.

F. Casella; P. Colonna

2012-01-01T23:59:59.000Z

48

Assessing resilience and state-transition models with historical records of cheatgrass Bromus tectorum  

E-Print Network (OSTI)

Assessing resilience and state-transition models with historical records of cheatgrass Bromus. Bestelmeyer2 and X. Ben Wu1 1 Department of Ecosystem Science and Management, Texas A&M University, 2138 TAMU. This requires management frameworks that can assess ecosystem dynamics, both within and between alternative

49

Assessment of Algal Farm Designs using a Dynamic Modular Approach  

SciTech Connect

The notion of renewable energy provides an importantmechanism for diversifying an energy portfolio,which ultimately would have numerous benefits including increased energy resilience, reduced reliance on foreign energysupplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth,and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associatedwith algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the development and application of the Algae Logistics Model (ALM) which is tailored to help address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments ofmultiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tierwere sub-selected and assessed using daily site-specific algaebiomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass productivity and that integration of novel dewatering equipment, order of operations, and equipment scaling can also have significant impacts on economics.

Jared M. Abodeely; Daniel M. Stevens; Allison E. Ray; Deborah T. Newby; Andre M. Coleman; Kara G. Cafferty

2014-07-01T23:59:59.000Z

50

Assessment of Algal Farm Designs Using a Dynamic Modular Approach  

SciTech Connect

The notion of renewable energy provides an important mechanism for diversifying an energy portfolio, which ultimately would have numerous benefits including increased energy resilience, reduction of foreign energy supplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth, and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associated with algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the Algae Logistics Model (ALM) which helps to address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments of multiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tier were sub-selected and assessed using daily site-specific algae biomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass productivity and that integration of novel dewatering equipment, order of operations, and equipment scaling can also have significant impacts on economics.

Abodeely, Jared; Coleman, Andre M.; Stevens, Daniel M.; Ray, Allison E.; Cafferty, Kara G.; Newby, Deborah T.

2014-05-03T23:59:59.000Z

51

Phenomenological models of socioeconomic network dynamics  

Science Journals Connector (OSTI)

We study a general set of models of social network evolution and dynamics. The models consist of both a dynamics on the network and evolution of the network. Links are formed preferentially between “similar” nodes, where the similarity is defined by the particular process taking place on the network. The interplay between the two processes produces phase transitions and hysteresis, as seen using numerical simulations for three specific processes. We obtain analytic results using mean-field approximations, and for a particular case we derive an exact solution for the network. In common with real-world social networks, we find coexistence of high and low connectivity phases and history dependence.

George C. M. A. Ehrhardt; Matteo Marsili; Fernando Vega-Redondo

2006-09-13T23:59:59.000Z

52

Applied Dynamic Analysis of the Global Economy (ADAGE) Model | Open Energy  

Open Energy Info (EERE)

Applied Dynamic Analysis of the Global Economy (ADAGE) Model Applied Dynamic Analysis of the Global Economy (ADAGE) Model Jump to: navigation, search LEDSGP green logo.png FIND MORE DIA TOOLS This tool is part of the Development Impacts Assessment (DIA) Toolkit from the LEDS Global Partnership. Tool Summary LAUNCH TOOL Name: Applied Dynamic Analysis of the Global Economy (ADAGE) Model Agency/Company /Organization: Research Triangle Institute Sector: Climate, Energy Topics: Co-benefits assessment, - Macroeconomic, Pathways analysis Resource Type: Software/modeling tools User Interface: Desktop Application Complexity/Ease of Use: Advanced Website: www.rti.org/page.cfm?objectid=DDC06637-7973-4B0F-AC46B3C69E09ADA9 RelatedTo: Electricity Markets Analysis (EMA) Model Cost: Paid Applied Dynamic Analysis of the Global Economy (ADAGE) Model Screenshot

53

Modeling of Reactor Kinetics and Dynamics  

SciTech Connect

In order to model a full fuel cycle in a nuclear reactor, it is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by coupling fuel burnup equations with the kinetics equations. When the equations are solved simultaneously with a nonlinear equation solver, the end result is a code with the unique capability of modeling transients at any time during a fuel cycle.

Matthew Johnson; Scott Lucas; Pavel Tsvetkov

2010-09-01T23:59:59.000Z

54

Modeling joint friction in structural dynamics.  

SciTech Connect

The presence of mechanical joints--typified by the lap joint--in otherwise linear structures has been accommodated in structural dynamics via ad hoc methods for a century. The methods range from tuning linear models to approximate non-linear behavior in restricted load ranges to various methods which introduce joint dissipation in a post-processing stage. Other methods, employing constitutive models for the joints are being developed and their routine use is on the horizon.

Segalman, Daniel Joseph

2005-05-01T23:59:59.000Z

55

Computable General Equilibrium Models for Sustainability Impact Assessment:  

Open Energy Info (EERE)

Computable General Equilibrium Models for Sustainability Impact Assessment: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Agency/Company /Organization: DG Joint Research Centre, European Commission, University of Heidelberg Topics: Co-benefits assessment Resource Type: Guide/manual, Publications, Software/modeling tools User Interface: Other Website: iatools.jrc.ec.europa.eu/docs/ecol_econ_2006.pdf Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Screenshot References: Computable general equilibrium models[1] Abstract "Sustainability Impact Assessment (SIA) of economic, environmental, and

56

Considering Time in LCA: Dynamic LCA and Its Application to Global Warming Impact Assessments  

Science Journals Connector (OSTI)

The lack of temporal information is an important limitation of life cycle assessment (LCA). A dynamic LCA approach is proposed to improve the accuracy of LCA by addressing the inconsistency of temporal assessment. This approach consists of first computing ...

Annie Levasseur; Pascal Lesage; Manuele Margni; Louise Deschênes; Réjean Samson

2010-03-19T23:59:59.000Z

57

Dynamic model of hysteretic elastic systems  

Science Journals Connector (OSTI)

A model for the dynamical behavior of a hysteretic elastic system is introduced and studied numerically. This model consists of a chain of hysteretic elastic elements. Each elastic element is a spring with properties that depend on an Ising-like state variable having Brownian dynamics in an energy landscape with structure that is sensitive to the forces which the elastic element must support. A single elastic element is studied carefully, numerically in order to establish its basic behavior. A one dimensional chain of N=500 elastic elements, driven like a resonant bar, is studied numerically. The data from this study are analyzed by the methods employed in analyzing similar experimental data. The behavior of the numerical model compares well with the behavior of physical realizations of hysteretic elastic systems.

Barbara Capogrosso-Sansone and R. A. Guyer

2002-12-05T23:59:59.000Z

58

Assessing Uncertainty in Spatial Exposure Models for Air Pollution Health Effects Assessment  

E-Print Network (OSTI)

Holgate S. 2002. Air pollution and health. Lancet Brunekreef2006. Bayesian modeling of air pollution health effects withExposure Models for Air Pollution Health Effects Assessment

2007-01-01T23:59:59.000Z

59

TEPP Model Needs Assessment Document | Department of Energy  

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

Model Needs Assessment Document Model Needs Assessment Document TEPP Model Needs Assessment Document The purpose of this Model Needs Assessment is to assist state, tribal, or local officials in determining emergency responder readiness for response to a transportation accident involving radioactive material. This Model Needs Assessment was developed by the Department of Energy's Transportation Emergency Preparedness Program (TEPP) as a planning and assessment tool for state, tribal, or local government officials. To implement this Model Needs Assessment, a designated official from the jurisdiction will conduct a self-assessment by answering various questions. By doing so, the official will determine strengths and identify improvement areas. To support the assessment process, and any proposed recommendations for improvement, this document includes

60

Receptor modeling assessment of particle total exposure assessment methodology data  

SciTech Connect

Data from the 1991 Particle Total Exposure Assessment Methodology (PTEAM) study in Riverside, CA, were analyzed using a new receptor modeling method. In this study, ambient (outdoor), indoor, and personal particulate matter (PM) concentrations and elemental concentrations of PM{sub 2.5} and PM{sub 10} were measured for a number of participants. These measurements made is possible to relate the pollution to which people were exposed throughout their daily activities with the outdoor air conditions. Personal daytime concentrations of the PM{sub 10} and majority of elements were significantly higher than outdoor or indoor concentrations, suggesting that a significant part of personal aerosol exposure is the result of personal daily activities. Possible sources of additional particulate mass include resuspension of particles that penetrate from the outdoors and formation of new particles during cooking, smoking, etc. Positive matrix factorization analysis was performed to describe the sources of personal exposure. To identify relative contribution of different sources, regression of the particulate matter mass against the factor contributions was performed. Major sources of PM{sub 2.5} were oil combustion, nonferrous metal operations, and motor vehicles. The mass contributions of particles from these sources were similar for outdoor air and personal exposure. Personal exposure to particles from these sources can be controlled by changing outdoor sources. The primary source of PM{sub 10} was soil.

Yakovleva, E.; Hopke, P.K.; Wallace, L.

1999-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Assessment of Combustion and Turbulence Models for the Simulation...  

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

Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine Assessment of Combustion and Turbulence Models for the Simulation of Combustion...

62

Library for modeling and simulating the thermal dynamics of buildings  

Science Journals Connector (OSTI)

Today's buildings consume more energy than any other sector of the U.S. economy, including transportation and industry; a similar importance can be expected in most European countries. Due to the increased interest in saving energy in buildings, new dynamic thermal models that describe transient response in more flexible modeling languages become necessary. Traditional building simulation software (e.g. TRNSYS or Energy Plus) are based on almost intractable simulation codes, difficult to maintain and modify, that predict system quantities at fixed time intervals. More clear code, properly separated from the simulation environment, with variable time step solvers would be necessary for the assessment of HVAC system performance with quicker dynamics. Following some ideas from a previous building thermal behavior library, a new enhanced Modelica library for modeling buildings is presented. The library basically consists of a combination of lumped parameter models and one-dimensional distributed parameter models that interconnects with each other through a set of common interfaces. Object-oriented features like class parameters and multiple-inheritance are used to improve the library structure making it easy to read and use. Complex building topologies can be built-up from component blocks that result in physically correct compound models that can be efficiently simulated and studied in any Modelica simulation environment.

Juan I. Videla; Bernt Lie

2006-01-01T23:59:59.000Z

63

The dynamic radiation environment assimilation model (DREAM)  

SciTech Connect

The Dynamic Radiation Environment Assimilation Model (DREAM) is a 3-year effort sponsored by the US Department of Energy to provide global, retrospective, or real-time specification of the natural and potential nuclear radiation environments. The DREAM model uses Kalman filtering techniques that combine the strengths of new physical models of the radiation belts with electron observations from long-term satellite systems such as GPS and geosynchronous systems. DREAM includes a physics model for the production and long-term evolution of artificial radiation belts from high altitude nuclear explosions. DREAM has been validated against satellites in arbitrary orbits and consistently produces more accurate results than existing models. Tools for user-specific applications and graphical displays are in beta testing and a real-time version of DREAM has been in continuous operation since November 2009.

Reeves, Geoffrey D [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Tokar, Robert L [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory; Friedel, Reiner H [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

64

DYNAMICAL MODELING OF GALAXY MERGERS USING IDENTIKIT  

SciTech Connect

We present dynamical models of four interacting systems: NGC 5257/8, The Mice, the Antennae, and NGC 2623. The parameter space of the encounters are constrained using the Identikit model-matching and visualization tool. Identikit utilizes hybrid N-body and test particle simulations to enable rapid exploration of the parameter space of galaxy mergers. The Identikit-derived matches of these systems are reproduced with self-consistent collisionless simulations which show very similar results. The models generally reproduce the observed morphology and H I kinematics of the tidal tails in these systems with reasonable properties inferred for the progenitor galaxies. The models presented here are the first to appear in the literature for NGC 5257/8 and NGC 2623, and The Mice and the Antennae are compared with previously published models. Based on the assumed mass model and our derived initial conditions, the models indicate that the four systems are currently being viewed 175-260 Myr after first passage and cover a wide range of merger stages. In some instances there are mismatches between the models and the data (e.g., in the length of a tail); these are likely due to our adoption of a single mass model for all galaxies. Despite the use of a single mass model, these results demonstrate the utility of Identikit in constraining the parameter space for galaxy mergers when applied to real data.

Privon, G. C.; Evans, A. S. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Barnes, J. E. [Institute for Astronomy, University of Hawaii, at Manoa, Honolulu, HI (United States); Hibbard, J. E. [National Radio Astronomy Observatory, Charlottesville, VA 22904 (United States); Yun, M. S. [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Mazzarella, J. M. [NASA Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Armus, L.; Surace, J., E-mail: gcp8y@virginia.edu [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-07-10T23:59:59.000Z

65

Computational battery dynamics (CBD)--electrochemical/thermal coupled modeling and multi-scale modeling  

E-Print Network (OSTI)

Computational battery dynamics (CBD)--electrochemical/thermal coupled modeling and multi the development of first-principles based mathematical models for batteries developed on a framework parallel to computation fluid dynamics (CFD), herein termed computational battery dynamics (CBD). This general

66

Indicators to support the dynamic evaluation of air quality models  

Science Journals Connector (OSTI)

Abstract Air quality models are useful tools for the assessment and forecast of pollutant concentrations in the atmosphere. Most of the evaluation process relies on the “operational phase” or in other words the comparison of model results with available measurements which provides insight on the model capability to reproduce measured concentrations for a given application. But one of the key advantages of air quality models lies in their ability to assess the impact of precursor emission reductions on air quality levels. Models are then used in a dynamic mode (i.e. response to a change in a given model input data) for which evaluation of the model performances becomes a challenge. The objective of this work is to propose common indicators and diagrams to facilitate the understanding of model responses to emission changes when models are to be used for policy support. These indicators are shown to be useful to retrieve information on the magnitude of the locally produced impacts of emission reductions on concentrations with respect to the “external to the domain” contribution but also to identify, distinguish and quantify impacts arising from different factors (different precursors). In addition information about the robustness of the model results is provided. As such these indicators might reveal useful as first screening methodology to identify the feasibility of a given action as well as to prioritize the factors on which to act for an increased efficiency. Finally all indicators are made dimensionless to facilitate the comparison of results obtained with different models, different resolutions, or on different geographical areas.

P. Thunis; A. Clappier

2014-01-01T23:59:59.000Z

67

A Game-Theoretical Dynamic Model for Electricity Markets  

E-Print Network (OSTI)

Oct 6, 2010 ... Abstract: We present a game-theoretical dynamic model for competitive electricity markets.We demonstrate that the model can be used to ...

Aswin Kannan

2010-10-06T23:59:59.000Z

68

Modeling organic matter dynamics in conifer-broadleaf forests in different site types upon fires: A computational experiment  

Science Journals Connector (OSTI)

The effect of forest fires differing in intensity on organic matter dynamics in forest soils has been assessed in different types of forest sites using the EFIMOD system of models. Differences between the patt...

A. S. Komarov; T. S. Kubasova

2007-08-01T23:59:59.000Z

69

MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL  

E-Print Network (OSTI)

MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL David G. Rossiter of Agronomy, Inc. #12;MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL Abstract Modeling inter-species competition is a natural application for dynamic simulation models

Rossiter, D G "David"

70

Financial and Cost Assessment Model (FICAM) | Open Energy Information  

Open Energy Info (EERE)

Financial and Cost Assessment Model (FICAM) Financial and Cost Assessment Model (FICAM) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Financial and Cost Assessment Model (FICAM) Agency/Company /Organization: UNEP-Risoe Centre Sector: Climate Focus Area: Greenhouse Gas Topics: Finance, Baseline projection, GHG inventory Resource Type: Software/modeling tools User Interface: Spreadsheet Website: tech-action.org/models.htm Cost: Free Financial and Cost Assessment Model (FICAM) Screenshot References: FICAM[1] "The Financial and Cost Assessment Model (FICAM) evaluates the contribution of technologies and practices towards mitigation of greenhouse gases, and carries a comprehensive financial analysis." References ↑ "FICAM" Retrieved from "http://en.openei.org/w/index.php?title=Financial_and_Cost_Assessment_Model_(FICAM)&oldid=383091"

71

ESD.864 Modeling and Assessment for Policy, Spring 2011  

E-Print Network (OSTI)

ESD.864 Modeling and Assessment for Policy explores how scientific information and quantitative models can be used to inform policy decision-making. Students will develop an understanding of quantitative modeling techniques ...

Selin, Noelle

72

A Dynamical IS-LM Model Allen Tang  

E-Print Network (OSTI)

A Dynamical IS-LM Model Allen Tang The University of North Carolina the specifications of a discrete dynamical IS-LM model and discuss how this model can of monetary policy, to an economy. The standard static IS-LM model arises

Marzuola, Jeremy

73

Integrated Assessment Modeling of Carbon Sequestration and Land Use Emissions Using Detailed Model Results and Observations  

SciTech Connect

This report outlines the progress on the development and application of Integrated Assessment Modeling of Carbon Sequestrations and Land Use Emissions supported by the DOE Office of Biological and Environmental Research (OBER), U.S. Department of Energy, Grant No. DOE-DE-FG02-01ER63069. The overall objective of this collaborative project between the University of Illinois at Urbana-Champaign (UIUC), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL) was to unite the latest advances in carbon cycle research with scientifically based models and policy-related integrated assessment tools that incorporate computationally efficient representations of the latest knowledge concerning science and emission trajectories, and their policy implications. As part of this research we accomplished the following tasks that we originally proposed: (1) In coordination with LLNL and ORNL, we enhanced the Integrated Science Assessment Model's (ISAM) parametric representation of the ocean and terrestrial carbon cycles that better represent spatial and seasonal variations, which are important to study the mechanisms that influence carbon sequestration in the ocean and terrestrial ecosystems; (2) Using the MiniCAM modeling capability, we revised the SRES (IPCC Special Report on Emission Scenarios; IPCC, 2000) land use emission scenarios; and (3) On the application front, the enhanced version of ISAM modeling capability is applied to understand how short- and long-term natural carbon fluxes, carbon sequestration, and human emissions contribute to the net global emissions (concentrations) trajectories required to reach various concentration (emission) targets. Under this grant, 21 research publications were produced. In addition, this grant supported a number of graduate and undergraduate students whose fundamental research was to learn a disciplinary field in climate change (e.g., ecological dynamics and ocean circulations) and then complete research on how this field could be linked to the other factors we need to consider in its dynamics (e.g., land use, ocean and terrestrial carbon sequestration and climate change).

Dr. Atul Jain

2005-04-17T23:59:59.000Z

74

Towards a Simplified Dynamic Wake Model using POD Analysis  

E-Print Network (OSTI)

We apply the proper orthogonal decomposition (POD) to large eddy simulation data of a wind turbine wake in a turbulent atmospheric boundary layer. The turbine is modeled as an actuator disk. Our analyis mainly focuses on the question whether POD could be a useful tool to develop a simplified dynamic wake model. The extracted POD modes are used to obtain approximate descriptions of the velocity field. To assess the quality of these POD reconstructions, we define simple measures which are believed to be relevant for a sequential turbine in the wake such as the energy flux through a disk in the wake. It is shown that only a few modes are necessary to capture basic dynamical aspects of these measures even though only a small part of the turbulent kinetic energy is restored. Furthermore, we show that the importance of the individual modes depends on the measure chosen. Therefore, the optimal choice of modes for a possible model could in principle depend on the application of interest. We additionally present a pos...

Bastine, David; Wächter, Matthias; Peinke, Joachim

2014-01-01T23:59:59.000Z

75

Censored Glauber Dynamics for the Mean Field Ising Model  

E-Print Network (OSTI)

dynamics for the Mean-?eld Ising Model: cut-off, criticaldynamics for the mean-?eld Ising model. Commun. Math. Phys.to equilibrium of stochastic Ising models in the Dobrushin

Ding, Jian; Lubetzky, Eyal; Peres, Yuval

2009-01-01T23:59:59.000Z

76

Open problem: Dynamic Relational Models for Improved Hazardous Weather Prediction  

E-Print Network (OSTI)

. Current weather radar detection and prediction sys- tems primarily rely on numerical models. We proposeOpen problem: Dynamic Relational Models for Improved Hazardous Weather Prediction Amy McGovern1, #12;Dynamic Relational Models for Improved Hazardous Weather Prediction Radar velocity Radar

McGovern, Amy

77

HOMOGENEOUS MODELS IN GENERAL RELATIVITY AND GAS DYNAMICS  

E-Print Network (OSTI)

HOMOGENEOUS MODELS IN GENERAL RELATIVITY AND GAS DYNAMICS O. I. BOGOYAVLENSKII AND S. P. NOVIKOV analytically) in general relativity and gas dynamics. The investigation of these models is carried out begins with a short survey of results on non-trivial models (that is, those that are not integrable

Novikov, Sergei Petrovich

78

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part II: Mooring line and structural dynamics  

Science Journals Connector (OSTI)

Abstract The need to exploit enhanced wind resources far offshore as well as in deep waters requires the use of floating support structures to become economically viable. The conventional three-bladed horizontal axis wind turbine may not continue to be the optimal design for floating applications. Therefore it is important to assess alternative concepts in this context that may be more suitable. Vertical axis wind turbines (VAWTs) are a promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess their technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This second article focuses on the modelling of mooring systems and structural behaviour of floating VAWTs, discussing various mathematical models and their suitability within the context of developing a model of coupled dynamics. Emphasis is placed on computational aspects of model selection and development as computational efficiency is an important aspect during preliminary design stages. This paper has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu; Athanasios Kolios

2014-01-01T23:59:59.000Z

79

Smoothing in dynamic generalized linear models by Gibbs sampling  

Science Journals Connector (OSTI)

Optimal filtering and smoothing in non-Gaussian dynamic models based on ... approach for obtaining posterior mean smoothers in the exponential family framework. Implementation and performance are investigated...

Ludwig Fahrmeir; Wolfgang Hennevogl…

1992-01-01T23:59:59.000Z

80

Wind Energy Assessment using a Wind Turbine with Dynamic Yaw Control.  

E-Print Network (OSTI)

??The goal of this project was to analyze the wind energy potential over Lake Michigan. For this purpose, a dynamic model of a utility-scale wind… (more)

Pervez, Md Nahid

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Modeling Dynamics and Exploring Control of a Single-Wheeled Dynamically Stable Mobile  

E-Print Network (OSTI)

Modeling Dynamics and Exploring Control of a Single-Wheeled Dynamically Stable Mobile Robot. It actively balances and moves on a single wheel using closed loop feedback, making it dynamically stable it a good candidate for operating in human environments. Balancing on a ball allows Ballbot to be omni

82

A dynamic model for the Lagrangian stochastic dispersion coefficient  

SciTech Connect

A stochastic sub-grid model is often used to accurately represent particle dispersion in turbulent flows using large eddy simulations. Models of this type have a free parameter, the dispersion coefficient, which is not universal and is strongly grid-dependent. In the present paper, a dynamic model for the evaluation of the coefficient is proposed and validated in decaying homogeneous isotropic turbulence. The grid dependence of the static coefficient is investigated in a turbulent mixing layer and compared to the dynamic model. The dynamic model accurately predicts dispersion statistics and resolves the grid-dependence. Dispersion statistics of the dynamically calculated constant are more accurate than any static coefficient choice for a number of grid spacings. Furthermore, the dynamic model produces less numerical artefacts than a static model and exhibits smaller sensitivity in the results predicted for different particle relaxation times.

Pesmazoglou, I.; Navarro-Martinez, S., E-mail: s.navarro@imperial.ac.uk [Department of Mechanical Engineering, Imperial College, London SW7 2AZ (United Kingdom); Kempf, A. M. [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)] [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)

2013-12-15T23:59:59.000Z

83

Event-Based Approach to Modelling Dynamic Architecture  

E-Print Network (OSTI)

Event-Based Approach to Modelling Dynamic Architecture: Application to Mobile Ad-Hoc Network.Attiogbe@univ-nantes.fr Abstract. We describe an event-based approach to specifiy systems with dynamically evolving architecture tools. Keywords: Specification, Verification, Dynamic Architecture, Event B. 1 Introduction Distributed

Paris-Sud XI, Université de

84

Dynamic Modeling of a Two Wheeled Vehicle : Jourdain Formalism  

E-Print Network (OSTI)

This paper presents a motorcycle direct dynamic formulation by the Jourdain's principle approach on the motorcycle's handlebar. Simulation results reveal some dynamics features like load transfer and counter-steering phenomena. keywords Motorcycle modeling, motorcycle control, Jourdain's dynamics principle. 1 Introduction

Paris-Sud XI, Université de

85

A dynamic term structure model of Central Bank policy  

E-Print Network (OSTI)

This thesis investigates the implications of explicitly modeling the monetary policy of the Central Bank within a Dynamic Term Structure Model (DTSM). We follow Piazzesi (2005) and implement monetary policy by including ...

Staker, Shawn W

2009-01-01T23:59:59.000Z

86

The development of an integrated model for assessing sustainability of complex systems  

Science Journals Connector (OSTI)

Currently, there are numerous indicators (single and composite) for measuring impacts in the three pillars, though current thinking emphasises the need for system thinking rather than the reductionist concept of pillars. Most existing indices/methods measure single aspects of sustainability and the more integrated indicators are aimed at national or global level assessments. A review of existing indicators, methods and models within the context of complex system sustainability showed that no single existing index, method or model was able to assess sustainability of complex systems. Most fail to account for complex system characteristics, such as system dynamics, interconnections and interdependencies of system components, a system's ability to learn and remember, emergence of novel behaviours, co-evolution, etc. This paper presents the methodology used to develop a new model for assessing sustainability of complex systems based on risk.

Gayathri Babarenda Gamage; Carol Boyle; Ron McDowall

2013-01-01T23:59:59.000Z

87

A computational fluid dynamics model for wind simulation: model implementation and experimental validation  

Science Journals Connector (OSTI)

To provide physically based wind modelling for wind erosion research at regional scale, a 3D computational fluid dynamics (CFD) wind model was developed. The model was programmed ... analysis and modelling tool (...

Zhuo-dong Zhang; Ralf Wieland; Matthias Reiche…

2012-04-01T23:59:59.000Z

88

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part III: Hydrodynamics and coupled modelling approaches  

Science Journals Connector (OSTI)

Abstract The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative configurations in this context. Vertical axis wind turbines (VAWTs) are one promising configuration, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess the technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This third article focuses on approaches to develop an efficient coupled model of dynamics (considering aerodynamics, hydrodynamics, structural and mooring line dynamics, and control dynamics) for floating VAWTs, as well as suitable ‘semi-analytical’ hydrodynamic models for this type of coupled dynamics models. Emphasis is also placed on utilising computationally efficient models and programming strategies. A comparison of the various forces acting on a floating VAWT with the three main floating support structure (spar, semi-submersible and tension-leg-platform) is also presented to highlight the relative dominant forces and hence importance of model accuracy representing these forces. Lastly a concise summary covering this series of articles is presented to give the reader an overview of this interdisciplinary research area. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu

2014-01-01T23:59:59.000Z

89

Dioxins in San Francisco Conceptual Model/Impairment Assessment  

E-Print Network (OSTI)

FINAL Dioxins in San Francisco Bay Conceptual Model/Impairment Assessment Prepared by Mike Connor Partnership November 12, 2004 SFEI Contribution #309 #12;Dioxins in San Francisco Bay: Impairment Assessment. This CM/IA report examines dioxins in San Francisco Bay. Dioxins comprise a group of several hundred

90

Assessing Carbon Dynamics in Semiarid Ecosystems: Balancing Potential Gains with Potential Large Rapid Losses  

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

Assessing Carbon Dynamics in Semiarid Ecosystems: Assessing Carbon Dynamics in Semiarid Ecosystems: Balancing Potential Gains With Potential Large Rapid Losses David D. Breshears (daveb@lanl.gov; 505-665-2803) Environmental Dynamics and Spatial Analysis Group (EES-10), Mail Stop J495 Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos, NM 87545 Michael H. Ebinger (mhe@lanl.gov, 505-667-4417) Environmental Dynamics and Spatial Analysis Group (EES-10), Mail Stop J495 Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos, NM 87545 Pat J. Unkefer (punkefer@lanl.gov, 505-665-2803) Biosciences Division, BS-1 Los Alamos National Laboratory Los Alamos, NM 87545 Craig D. Allen (craig_allen@usgs.gov, 505-672-3861, Ext. 541) U. S. Geological Survey, Midcontinent Ecological Science Center

91

Learning Usability Assessment Models for Web Sites  

E-Print Network (OSTI)

. Published books in the field include work by Cooper [Cooper et al. 2007], Dix [Dix 1998], Nielsen [Nielsen 2000], Norman [Norman 2002], Shneiderman [Shneiderman and Plaisant 2010], and Tidwell [Tidwell 2006]. Heuristic Evaluation When evaluating a... Web site for usability issues, usability inspection is an approach for evaluating the usability of user interfaces without those for whom the interface is designed being present [Nielsen 1994]. Usability inspection applies methods to assess...

Davis, Paul

2012-02-14T23:59:59.000Z

92

Co-benefits Risk Assessment (COBRA) Screening Model | Open Energy  

Open Energy Info (EERE)

Co-benefits Risk Assessment (COBRA) Screening Model Co-benefits Risk Assessment (COBRA) Screening Model Jump to: navigation, search Tool Summary Name: Co-benefits Risk Assessment (COBRA) Screening Model Agency/Company /Organization: United States Environmental Protection Agency Sector: Climate Complexity/Ease of Use: Moderate Website: www.epa.gov/statelocalclimate/resources/cobra.html Cost: Free Related Tools Tool for Selecting CDM Methods & Technologies Modular Applied General Equilibrium Tool (MAGNET) COMMUTER Model ... further results Find Another Tool FIND DEVELOPMENT IMPACTS ASSESSMENT TOOLS Automated tool that can be downloaded from the website. Converts emissions reductions into air quality improvements, estimates annual adverse health impacts avoided, and monetizes the value of these. Approach COBRA converts emissions reductions into air quality improvements, and

93

MURDAM1.0. Minority Utility Rate Design Assessment Model  

SciTech Connect

Econometric model simulates consumer demand response to various user-supplied, two-part tariff electricity rate designs and assesses their economic welfare impact on black, hispanic, poor and majority households.

Poyer, D.A.; Butler, J.G. [Argonne National Lab., IL (United States)

1993-01-20T23:59:59.000Z

94

Quantitative Adaptation Analytics for Assessing Dynamic Systems of Systems.  

SciTech Connect

Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.

Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.; Le, Hai D.; Kao, Gio K; Melander, Darryl J.; Longsine, Dennis Earl [Sandia National Laboratories, Unknown, Unknown; Vander Meer, Robert Charles,

2015-01-01T23:59:59.000Z

95

RAVEN and Dynamic Probabilistic Risk Assessment: Software overview  

SciTech Connect

RAVEN is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. The initial development was aimed to provide dynamic risk analysis capabilities to the Thermo-Hydraulic code RELAP-7 [], currently under development at the Idaho National Laboratory. Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose probabilistic and uncertainty quantification platform, capable to agnostically communicate with any system code. This agnosticism has been employed by providing Application Programming Interfaces (APIs). These interfaces are used to allow RAVEN to interact with any code as long as all the parameters that need to be perturbed are accessible by inputs files or via python interfaces. RAVEN is capable to investigate the system response, investigating the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. The paper presents an overview of the software capabilities and their implementation schemes followed by some application examples.

Andrea Alfonsi; Cristian Rabiti; Diego Mandelli; Joshua Cogliati; Robert Kinoshita; Antonio Naviglio

2014-06-01T23:59:59.000Z

96

Appendix MASS: Performance Assessment Modeling Assumptions  

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

Rock Units MASS-12.2 Historical Context of the Salado Conceptual Model MASS-12.3 The Fracture Model MASS-12.4 Flow in the DRZ MASS-12.5 Actinide Transport in the Salado MASS-13.0...

97

Modeling dilute sediment suspension using large-eddy simulation with a dynamic mixed model  

E-Print Network (OSTI)

Modeling dilute sediment suspension using large-eddy simulation with a dynamic mixed model Yi Transport of suspended sediment in high Reynolds number channel flows Re=O 600 000 is simulated using large-eddy simulation along with a dynamic-mixed model DMM . Because the modeled sediment concentration is low

Fringer, Oliver B.

98

Subcycled dynamics in the Spectral Community Atmosphere Model, version 4  

SciTech Connect

To gain computational efficiency, a split explicit time integration scheme has been implemented in the CAM spectral Eulerian dynamical core. In this scheme, already present in other dynamical core options within the Community Atmosphere Model, version 4 (CAM), the fluid dynamics portion of the model is subcycled to allow a longer time step for the parameterization schemes. The physics parameterization of CAM is not subject to the stability restrictions of the fluid dynamics, and thus finer spatial resolutions of the model do not require the physics time step to be reduced. A brief outline of the subcycling algorithm implementation and resulting model efficiency improvement is presented. A discussion regarding the effect of the climate statistics derived from short model runs is provided.

Taylor, Mark [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Evans, Katherine J [ORNL] [ORNL; Hack, James J [ORNL] [ORNL; Worley, Patrick H [ORNL] [ORNL

2010-01-01T23:59:59.000Z

99

The Mixing Time Evolution of Glauber Dynamics for the Mean-Field Ising Model  

E-Print Network (OSTI)

dynamics for the mean-?eld Ising model. http://arxiv. org/dynamics for the mean-?eld Ising model: cut-off, criticalDynamics for the Mean-Field Ising Model Jian Ding 1, , Eyal

Ding, Jian; Lubetzky, Eyal; Peres, Yuval

2009-01-01T23:59:59.000Z

100

Fibre Based Modeling of Wood Dynamics and Fracture  

E-Print Network (OSTI)

Fibre Based Modeling of Wood Dynamics and Fracture by Sean Meiji Sutherland B.Sc., The University for the simulation of the dynamics and fracturing char- acteristics of wood, specifically its anisotropic behaviour bundles of fibres. Additionally, we describe the conditions under which fracture occurs in the material

Bridson, Robert

Note: This page contains sample records for the topic "dynamics models assessing" 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

Dynamic Modelling for Control of Fuel Cells Federico Zenith  

E-Print Network (OSTI)

Dynamic Modelling for Control of Fuel Cells Federico Zenith Sigurd Skogestad Department of Chemical Engineering Norwegian University of Science and Technology ( ntnu) Trondheim Abstract Fuel-cell dynamics have been investigated with a variable-resistance board applied to a high temperature polymer fuel cell

Skogestad, Sigurd

102

A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling  

E-Print Network (OSTI)

A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling and Control L. Nehaoua of these techniques to other simulators (cars and motorcycles) is possible but not direct. Indeed, the dynamics motorcycle driving simulators were build. The first prototype was developed by Honda in 1988

Paris-Sud XI, Université de

103

Dynamic energy budget approaches for modelling organismal ageing  

Science Journals Connector (OSTI)

...quantitative approach. New York, NY: Harwood Academic...1928 The rate of living. New York, NY: Knopf. Ricklefs...A. L. M. 2010 Dynamic energy budget theory restores coherence...Nothobranchius furzeri as a new model system for aging studies...

2010-01-01T23:59:59.000Z

104

Applications of axial and radial compressor dynamic system modeling  

E-Print Network (OSTI)

The presented work is a compilation of four different projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. ...

Spakovszky, Zoltán S. (Zoltán Sándor), 1972-

2001-01-01T23:59:59.000Z

105

Assessment of dynamic energy conversion systems for radioisotope heat sources  

SciTech Connect

The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

Thayer, G.R.; Mangeng, C.A.

1985-06-01T23:59:59.000Z

106

Dynamics of Ising models with damping J. M. Deutsch  

E-Print Network (OSTI)

Dynamics of Ising models with damping J. M. Deutsch Department of Physics, University of California Donostia, Spain Received 30 August 2007; published 28 March 2008 We show for the Ising model, both from a theoretical standpoint and for numerical efficiency. Ising models are perhaps the best

Deutsch, Josh

107

Global registration of dynamic range scans for articulated model reconstruction  

Science Journals Connector (OSTI)

We present the articulated global registration algorithm to reconstruct articulated 3D models from dynamic range scan sequences. This new algorithm aligns multiple range scans simultaneously to reconstruct a full 3D model from the geometry of these scans. ... Keywords: Range scanning, animation reconstruction, articulated model, nonrigid registration

Will Chang; Matthias Zwicker

2011-05-01T23:59:59.000Z

108

Cognitive Modeling Carsten Pfeffer Dynamical Systems Approaches to  

E-Print Network (OSTI)

Cognitive Modeling Carsten Pfeffer Dynamical Systems Approaches to Cognition Carsten Pfeffer Universität Bremen December 1st, 2014 December 1st, 2014 1/30 #12;Cognitive Modeling Carsten Pfeffer Introduction Physical Symbol Systems December 1st, 2014 2/30 #12;Cognitive Modeling Carsten Pfeffer

Bremen, Universität

109

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS  

E-Print Network (OSTI)

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS Ugur Pasaogullari and Chao-dimensional model has been developed to simulate solid oxide fuel cells (SOFC). The model fully couples current density operation. INTRODUCTION Solid oxide fuel cells (SOFC) are among possible candidates

110

Dynamic (G2) Model Design Document, 24590-WTP-MDD-PR-01-002, Rev. 12  

SciTech Connect

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) Statement of Work (Department of Energy Contract DE-AC27-01RV14136, Section C) requires the contractor to develop and use process models for flowsheet analyses and pre-operational planning assessments. The Dynamic (G2) Flowsheet is a discrete-time process model that enables the project to evaluate impacts to throughput from eventdriven activities such as pumping, sampling, storage, recycle, separation, and chemical reactions. The model is developed by the Process Engineering (PE) department, and is based on the Flowsheet Bases, Assumptions, and Requirements Document (24590-WTP-RPT-PT-02-005), commonly called the BARD. The terminologies of Dynamic (G2) Flowsheet and Dynamic (G2) Model are interchangeable in this document. The foundation of this model is a dynamic material balance governed by prescribed initial conditions, boundary conditions, and operating logic. The dynamic material balance is achieved by tracking the storage and material flows within the plant as time increments. The initial conditions include a feed vector that represents the waste compositions and delivery sequence of the Tank Farm batches, and volumes and concentrations of solutions in process equipment before startup. The boundary conditions are the physical limits of the flowsheet design, such as piping, volumes, flowrates, operation efficiencies, and physical and chemical environments that impact separations, phase equilibriums, and reaction extents. The operating logic represents the rules and strategies of running the plant.

Deng, Yueying; Kruger, Albert A.

2013-12-16T23:59:59.000Z

111

Real-Time Dynamic Brake Assessment Conduct a proof-of-concept  

E-Print Network (OSTI)

Real-Time Dynamic Brake Assessment Purpose Conduct a proof-of-concept test to examine the Federal Motor Carrier Safety Administration's Vehicle and Roadside Operations Division Concept stemming conducted for the National Highway Transportation Safety Administration. Signals to be collected Real

112

New model describing the dynamical behaviour of penetration rates  

Science Journals Connector (OSTI)

We propose a hierarchical logistic equation as a model to describe the dynamical behaviour of a penetration rate of a prevalent stuff. In this model, a memory, how many people who already possess it a person who does not process it yet met, is considered, which does not exist in the logistic model. As an application, we apply this model to iPod sales data, and find that this model can approximate the data much better than the logistic equation.

Tohru Tashiro; Hiroe Minagawa; Michiko Chiba

2013-01-01T23:59:59.000Z

113

Developing Generic Dynamic Models for the 2030 Eastern Interconnection Grid  

SciTech Connect

The Eastern Interconnection Planning Collaborative (EIPC) has built three major power flow cases for the 2030 Eastern Interconnection (EI) based on various levels of energy/environmental policy conditions, technology advances, and load growth. Using the power flow cases, this report documents the process of developing the generic 2030 dynamic models using typical dynamic parameters. The constructed model was validated indirectly using the synchronized phasor measurements by removing the wind generation temporarily.

Kou, Gefei [ORNL; Hadley, Stanton W [ORNL; Markham, Penn N [ORNL; Liu, Yilu [ORNL

2013-12-01T23:59:59.000Z

114

E-Print Network 3.0 - assessing local model Sample Search Results  

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

OF ENGINEERING CYBERNETICS AND ROBOTICS, 60 Summary: , 60 2009 Sofia Service Oriented Architecture of Assessment Model1 Adelina Aleksieva... Assessment Model. To achieve...

115

Dynamic Analysis and Modeling of Jansen Mechanism  

Science Journals Connector (OSTI)

Abstract Theo Jansen mechanism is gaining wide spread popularity among legged robotics researchers due to its scalable design, energy efficiency, low payload to machine load ratio, bio-inspired locomotion, deterministic foot trajectory among others. In this paper, we present dynamic analysis of a four legged Theo Jansen link mechanism using projection method that results in constraint force and equivalent Lagrange's equation of motion necessary for any meaningful extension and/or optimization of this niche mechanism. Numerical simulations using MaTX is presented in conjunction with the dynamic analysis. This research sets a theoretical basis for future investigation into Theo Jansen mechanism.

Shunsuke Nansai; Mohan Rajesh Elara; Masami Iwase

2013-01-01T23:59:59.000Z

116

Workshop on Carbon Sequestration Science - Modeling and Integrated Assessment  

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

Modeling and Integrated Modeling and Integrated Assessment Howard Herzog MIT Energy Laboratory May 24, 2001 Economic Assessments * Engineering analysis of CO 2 separation and capture * Economic modeling/ integrated assessment of carbon capture and sequestration * Comparison on equal basis of the major sequestration options Economic Modeling Motivation * When might carbon capture and sequestration (CCS) become competitive? * What is its potential scale? * Which technologies look most promising? . . . . And when? * How to see the potential in a general market context? Detailed Reference *Sean Biggs Thesis: S Biggs, S. D., "Sequestering Carbon from Power Plants: The Jury is Still Out," M.I.T. Masters Thesis, (2000). S http://sequestration.mit.edu/pdf/SeanBiggs.pdf What Determines Competitiveness?

117

Modeling System Development for the Evaluation of Dynamic Air Quality  

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

Modeling System Development for the Evaluation of Dynamic Air Quality Modeling System Development for the Evaluation of Dynamic Air Quality Impacts of DER Speaker(s): Robert Van Buskirk Date: January 30, 2003 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Kristina LaCommare A critical challenge for the atmospheric sciences is to understand the anthropogenic impacts on atmospheric chemistry over spatial scales ranging from the urban to the regional, and ultimately to the global, and over corresponding time scales ranging from minutes to weeks and ultimately annual trends. A similar challenge for energy policymakers is to integrate an understanding of impact dynamics into the economic dynamics of energy supply and demand. The challenges of dynamic analysis of emissions impacts from the energy sector have substantially increased with a new

118

Microsoft PowerPoint - Real-Time Dynamic Brake Assessment poster.ppt [Compatibility Mode]  

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

Dynamic Brake Assessment Dynamic Brake Assessment Purpose Conduct a proof-of-concept test to examine the feasibility of developing an on-board system to assess a vehicle's ability to stop based on typical low-pressure in-service braking events. Partnerships H.T. Hackney Company MGM Brakes Overview Funded through the Federal Motor Carrier Safety Administration's Vehicle and Roadside Operations Division Concept stemming from on the Department of Energy's Medium Truck Duty Cycle research as well as previous research conducted for the National Highway Transportation Safety Administration. Signals to be collected Real-time brake application pressure Vehicle speed and acceleration GPS location and grade information Vehicle weight (current load) Engine parameters such as RPM and torque To be conducted October 2010 -

119

Safety assessment document for the Dynamic Test Complex B854  

SciTech Connect

A safety assessment was performed to determine if potential accidents at the 854 Complex at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The credible accidents that might have an effect on these facilities or have off-site consequences were considered. These were earthquake, extreme wind (including missiles), lightning, flood, criticality, high explosive (HE) detonation that disperses uranium and beryllium, spontaneous oxidation of plutonium, explosions due to finely divided particles, and a fire. Seismic and extreme wind (including missiles) analyses indicate that the buildings are basically sound. The lightning protection system is in the process of being upgraded to meet AMCR 385-100. These buildings are located high above the dry creek bed so that a flood is improbable. The probability of high explosive detonation involving plutonium is very remote since the radioactive materials are encased and plutonium and HE are not permitted concurrently in the same area at Site 300. (The exception to this policy is that explosive actuating devices are sometimes located in assemblies containing fissile materials. However, an accidental actuation will not affect the safe containment of the plutonium within the assembly.) There is a remote possibility of an HE explosion involving uranium and beryllium since these are permitted in the same area.The possibility of a criticality accident is very remote since the fissile materials are doubly encased in stout metal containers. All operations involving these materials are independently reviewed and inspected by the Criticality Safety Office. It was determined that a fire was unlikely due to the low fire loading and the absence of ignition sources. It was also determined that the consequences of any accidents were reduced by the remote location of these facilities, their design, and by administrative controls.

Odell, B.N.; Pfeifer, H.E.

1981-12-11T23:59:59.000Z

120

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint  

SciTech Connect

By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.

Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.

2005-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Structure formation: Models, Dynamics and Status  

E-Print Network (OSTI)

The constraints on the models for the structure formation arising from various cosmological observations at different length scales are reviewed. The status of different models for structure formation is examined critically in the light of these observations.

T. Padmanabhan

1995-08-25T23:59:59.000Z

122

More dynamical models of our Galaxy  

Science Journals Connector (OSTI)

......rapidly at z 1kpc. In general sigma mirrors v , rising as v falls. The bottom-left...data have been interpreted with either Schwarzschild models (Cappellari et al. ) or models...with greater ease than is possible with Schwarzschild models and greater rigour than the Jeans......

James Binney

2012-10-21T23:59:59.000Z

123

Bayesian Model Averaging in Proportional Hazard Models: Assessing the Risk of a Stroke  

E-Print Network (OSTI)

Bayesian Model Averaging in Proportional Hazard Models: Assessing the Risk of a Stroke Chris T In the context of the Cardiovascular Health Study, a comprehensive investigation into the risk factors for stroke of assessing who is at high risk for stroke. 1 Introduction Stroke is the third leading cause of death among

Volinsky, Chris

124

Dynamic modelling for thermal micro-actuators using thermal networks  

E-Print Network (OSTI)

Dynamic modelling for thermal micro-actuators using thermal networks Beatriz L´opez-Wallea,1 and analytical calculations. Key words: Micro-actuators, Thermal modelling, Electrical analogy, Thermal network 1 and MicroMechatronic Systems Department (AS2M), 24 rue Alain Savary, 25000 Besan¸con, France Abstract

Paris-Sud XI, Université de

125

Dynamic physiological modeling for functional diffuse optical tomography  

E-Print Network (OSTI)

,c and David A. Boasa a Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging and brain that reflect competing metabolic demands and cardiovascular dynamics. The diffuse nature of near- namic response. In this paper, we present a linear state-space model for DOT analysis that models

126

Computational Modeling of Brain Dynamics during Repetitive Head Motions  

E-Print Network (OSTI)

Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School motions in traumatic scenarios that are as- sociated with severe brain injuries. Our results are based on the linear Kelvin-Voigt brain injury model, which treats the brain matter as a viscoelastic solid, and on our

Burtscher, Martin

127

2 J. MANDEL ET AL. DYNAMIC DATA DRIVEN WILDFIRE MODELING  

E-Print Network (OSTI)

2 J. MANDEL ET AL. DYNAMIC DATA DRIVEN WILDFIRE MODELING J. MANDELa , M. CHENa , J.L. COENb , C of Colorado Denver, Denver, CO 80217-3364, USA b National Center for Atmospheric Research, Boulder, CO 80307. A proposed system for real-time modeling of wildfires is described. The system involves numerical weather

Douglas, Craig C.

128

Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations  

E-Print Network (OSTI)

.S.A. Abstract We numerically model the brain dy- namics during and after impulsive head translations using brain injuries appear among boxers and shaken babies despite minimal rotations of their heads. Modeling head translations also helps understand the brain dynamics during head rotations about an arbitrary

Burtscher, Martin

129

Dynamic model order reduction for shipboard integrated power systems  

Science Journals Connector (OSTI)

The shipboard integrated power system is modeled by a system of differential-algebraic equations with dynamics having time constants varying from fractions of a second to several minutes. Control and simulation of naval shipboard power systems for different ... Keywords: electric ship, integrated power system, model order reduction, shipboard power system, singular perturbation

Sudipta Lahiri; Dagmar Niebur; Harry Kwatny; Gaurav Bajpai

2009-07-01T23:59:59.000Z

130

A new analytic-adaptive model for EGS assessment, development and  

Open Energy Info (EERE)

new analytic-adaptive model for EGS assessment, development and new analytic-adaptive model for EGS assessment, development and management support Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title A new analytic-adaptive model for EGS assessment, development and management support Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Integrated Chemical, Thermal, Mechanical and Hydrological Modeling Project Description The University of Nevada - Reno (UNR), proposes to develop a new, integrated solution technique for simulating the Thermal, Hydrological, Mechanical, and Chemical (THMC) processes relevant to thermal energy extraction from an Enhanced Geothermal System (EGS). UNR defines the great challenges in numerical modeling as to (1) dealing with flows and transport in the stimulated fractures of the EGS of largely unknown geometry and characteristics; and (2) discovering the best possible cooling fluid circulation solution in the EGS by trial-and-error numerical simulations. The new THMC will have an adaptive, Computational Fluid Dynamics (CFD) component, integrated with the THMC rockmass model in order to match field test signatures, or desired outcomes in design hypothesis test. The project's main hypothesis is that there are new solutions to heat extraction from an as-created, enhanced fracture system of EGS. The project will develop a new THMC simulation model with new capabilities and prove the main hypothesis by and applying it to various EGS designs including emerging concepts, two-phase (steam-gas-liquid) coolant flows in the fracture network, and dynamic, huff-puff operations.

131

DYNAMICAL MODEL OF AN EXPANDING SHELL  

SciTech Connect

Expanding blast waves are ubiquitous in many astronomical sources, such as supernova remnants, X-ray emitting binaries, and gamma-ray bursts. I consider here the dynamics of such an expanding blast wave, both in the adiabatic and the radiative regimes. As the blast wave collects material from its surroundings, it decelerates. A full description of the temporal evolution of the blast wave requires consideration of both the energy density and the pressure of the shocked material. The obtained equation is different from earlier works in which only the energy was considered. The solution converges to the familiar results in both the ultrarelativistic and the sub-relativistic (Newtonian) regimes.

Pe'er, Asaf [Harvard-Smithsonian Center for Astrophysics, MS-51, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-06-10T23:59:59.000Z

132

Friction in a Model of Hamiltonian Dynamics  

E-Print Network (OSTI)

We study the motion of a heavy tracer particle weakly coupled to a dense ideal Bose gas exhibiting Bose-Einstein condensation. In the so-called mean-field limit, the dynamics of this system approaches one determined by nonlinear Hamiltonian evolution equations describing a process of emission of Cerenkov radiation of sound waves into the Bose-Einstein condensate along the particle's trajectory. The emission of Cerenkov radiation results in a friction force with memory acting on the tracer particle and causing it to decelerate until it comes to rest.

Juerg Froehlich; Zhou Gang; Avy Soffer

2011-10-29T23:59:59.000Z

133

Modeling of Alpine Atmospheric Dynamics II  

E-Print Network (OSTI)

for large mesh sizes (x 20 km) to vertically redistribute heat and moisture in a grid column when model in a numerical model Convective cloud systems are not resolved if the mesh size of the grid is larger than small to treat convection as sub-grid scale process but too large to treat it explicitly For example

Gohm, Alexander

134

Dynamic force spectroscopy on multiple bonds: experiments and model  

E-Print Network (OSTI)

We probe the dynamic strength of multiple biotin-streptavidin adhesion bonds under linear loading using the biomembrane force probe setup for dynamic force spectroscopy. Measured rupture force histograms are compared to results from a master equation model for the stochastic dynamics of bond rupture under load. This allows us to extract the distribution of the number of initially closed bonds. We also extract the molecular parameters of the adhesion bonds, in good agreement with earlier results from single bond experiments. Our analysis shows that the peaks in the measured histograms are not simple multiples of the single bond values, but follow from a superposition procedure which generates different peak positions.

T. Erdmann; S. Pierrat; P. Nassoy; U. S. Schwarz

2007-12-18T23:59:59.000Z

135

Dynamic modeling of steam power cycles: Part II – Simulation of a small simple Rankine cycle system  

Science Journals Connector (OSTI)

This paper presents the second part of the work concerning the dynamic simulation of small steam cycle plants for power generation. The work is part of the preliminary study for a 600 kWe biomass fired steam power plant for which the complete open-loop, lumped parameter dynamic model of the steam cycle has been developed using the SimECS software described in Part I of this work. For these low-power plants, a dynamic simulation tool is especially useful because these systems must be designed to operate in transient mode for most of the time. The plant model presented here consists of the following components: feedwater pump, economizer, evaporator, superheater, impulse turbine, electrical generator and condenser. The primary heat source is modeled as a flue gas flow and no combustion models are incorporated yet to model the furnace. A description of the various components forming the complete steam cycle is given to illustrate the capabilities and modularity of the developed modeling technique. The model is first validated quantitatively against steady-state values obtained using a well known, reliable steady-state process modeling software. Subsequently, the dynamic validation is presented. Results can only be discussed based on the qualitative assessment of the observed trends because measurements are not available, being the plant in the preliminary design phase. The qualitative validation is based on four dynamic simulations involving three small step disturbances of different magnitude imposed on the pump rotational speed and on the flue gas mass flow and a single large ramp disturbance on the flue gas mass flow.

H. van Putten; P. Colonna

2007-01-01T23:59:59.000Z

136

Contour dynamics model for electric discharges  

Science Journals Connector (OSTI)

We present an effective contour model for electrical discharges deduced as the asymptotic limit of the minimal streamer model for the propagation of electric discharges, in the limit of small electron diffusion. The incorporation of curvature effects to the velocity propagation and not to the boundary conditions is a feature and makes it different from the classical Laplacian growth models. The dispersion relation for a nonplanar two-dimensional discharge is calculated. The development and propagation of fingerlike patterns are studied and their main features quantified.

M. Arrayás, M. A. Fontelos, and C. Jiménez

2010-03-18T23:59:59.000Z

137

Assessing Impacts of Climate Change on Forests: The State of Biological Modeling  

DOE R&D Accomplishments (OSTI)

Models that address the impacts to forests of climate change are reviewed by four levels of biological organization: global, regional or landscape, community, and tree. The models are compared as to their ability to assess changes in greenhouse gas flux, land use, maps of forest type or species composition, forest resource productivity, forest health, biodiversity, and wildlife habitat. No one model can address all of these impacts, but landscape transition models and regional vegetation and land-use models consider the largest number of impacts. Developing landscape vegetation dynamics models of functional groups is suggested as a means to integrate the theory of both landscape ecology and individual tree responses to climate change. Risk assessment methodologies can be adapted to deal with the impacts of climate change at various spatial and temporal scales. Four areas of research development are identified: (1) linking socioeconomic and ecologic models, (2) interfacing forest models at different scales, (3) obtaining data on susceptibility of trees and forest to changes in climate and disturbance regimes, and (4) relating information from different scales.

Dale, V. H.; Rauscher, H. M.

1993-04-06T23:59:59.000Z

138

Assessment of boreal forest historical C dynamics in Yukon River Basin: relative roles of warming and fire regime change  

SciTech Connect

Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites and evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at ;0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink strength of boreal forests. It is also important for large-scale biogeochemical and earth system models to include organic soil dynamics in applications to assess regional C dynamics of boreal forests responding to warming and changes in fire regime.

Yuan, Fengming [ORNL; Yi, Shuhua [Cold and Arid Regions Environmental and Engineering Research Institute, CAS; McGuire, A. David [University of Alaska; Johnson, Kristopher D [University of Alaska, Fairbanks; Liang, Jingjing [University of Alaska, Fairbanks; Harden, Jennifer [USGS, Menlo Park, CA; Kasischke, Eric S. [University of Maryland, College Park; Kurz, Werner [Canadian Forest Service

2012-01-01T23:59:59.000Z

139

Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models  

E-Print Network (OSTI)

Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models J. R. Mc climate policy analysis. This paper examines the representation of carbon capture and storage (CCS carbon capture and storage, 2) a natural gas combined cycle technology with carbon capture and storage 1

140

Multi-attribute Model for Assessment of SMEs adoption of  

E-Print Network (OSTI)

Multi-attribute Model for Assessment of SMEs adoption of High Performance Computing Cloud Services boosters for SMEs, particularly manufacturing. · Huge amount of and $ are currently being spent on simulation experiments through various initiatives. #12;Introduction · Technology adoptance is in its early

Bohanec, Marko

Note: This page contains sample records for the topic "dynamics models assessing" 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

Modeling Infection with Multi-agent Dynamics  

E-Print Network (OSTI)

Developing the ability to comprehensively study infections in small populations enables us to improve epidemic models and better advise individuals about potential risks to their health. We currently have a limited ...

Dong, Wen

2012-01-01T23:59:59.000Z

142

THE WISCONSIN DYNAMICAL/MICROPHYSICAL MODEL  

E-Print Network (OSTI)

, assumed uniform, is dictated by quasi-compressible computational stability requirements. The computational an ellipsoidal warm bubble in the lower central part of the model domain, with the same relative humidities

Wang, Pao K.

143

Abstract--A stochastic dynamic programming hydrothermal dispatch model to simulate a bid-based market is  

E-Print Network (OSTI)

on dynamic programming that optimizes and validates the bid prices strategies for each power plant in a hydro-thermal several plants. Emphasis is given to hydro reservoir modeling and to the assessment of their market power market power is detected, focalized on main reservoir plants and implicating important increases

Catholic University of Chile (Universidad Católica de Chile)

144

Modelling a feed-water control system of a steam generator in the framework of the dynamic reliability  

E-Print Network (OSTI)

Modelling a feed-water control system of a steam generator in the framework of the dynamic with the exploration of an industrial complex system behaviour and its prob- abilistic safety assessment (PSA critical systems), the feed-water control system of a steam generator of a pressurised water nuclear

Paris-Sud XI, Université de

145

Asperity Model of an Earthquake - Dynamic Problem  

SciTech Connect

We develop an earthquake asperity model that explains previously determined empirical scaling relationships for repeating earthquakes along the San Andreas fault in central California. The model assumes that motion on the fault is resisted primarily by a patch of small strong asperities that interact with each other to increase the amount of displacement needed to cause failure. This asperity patch is surrounded by a much weaker fault that continually creeps in response to tectonic stress. Extending outward from the asperity patch into the creeping part of the fault is a shadow region where a displacement deficit exists. Starting with these basic concepts, together with the analytical solution for the exterior crack problem, the consideration of incremental changes in the size of the asperity patch leads to differential equations that can be solved to yield a complete static model of an earthquake. Equations for scalar seismic moment, the radius of the asperity patch, and the radius of the displacement shadow are all specified as functions of the displacement deficit that has accumulated on the asperity patch. The model predicts that the repeat time for earthquakes should be proportional to the scalar moment to the 1/6 power, which is in agreement with empirical results for repeating earthquakes. The model has two free parameters, a critical slip distance dc and a scaled radius of a single asperity. Numerical values of 0.20 and 0.17 cm, respectively, for these two parameters will reproduce the empirical results, but this choice is not unique. Assuming that the asperity patches are distributed on the fault surface in a random fractal manner leads to a frequency size distribution of earthquakes that agrees with the Gutenberg Richter formula and a simple relationship between the b-value and the fractal dimension. We also show that the basic features of the theoretical model can be simulated with numerical calculations employing the boundary integral method.

Johnson, Lane R.; Nadeau, Robert M.

2003-05-02T23:59:59.000Z

146

Integrated science model for assessment of climate change  

SciTech Connect

Integrated assessment models are intended to represent processes that govern physical, ecological, economic and social systems. This report describes a scientific model relating emissions to global temperature and sea level. This model is intended to be one component of an integrated assessment model which is, of course, much more comprehensive. The model is able to reproduce past changes in CO{sub 2} concentration, global temperature, and sea level. The model is used to estimate the emissions rates required to lead to stabilization of CO{sub 2} at various levels. The model is also used to estimate global temperature rise, the rate of temperature change, and sea level rise driven by IPCC emissions scenarios. The emission of fossil fuel CO{sub 2} is modeled to have the largest long term effect on climate. Results do show the importance of expected changes of trace greenhouse gases other than CO{sub 2} in the near future. Because of the importance of these other trace gases, further work is recommended to more accurately estimate their effects.

Jain, A.K.; Wuebbles, D.J. [Lawrence Livermore National Lab., CA (United States); Kheshgi, H.S. [Exxon Research and Engineering Co., Annandale, NJ (United States)

1994-04-01T23:59:59.000Z

147

Dynamics of Ising models with damping  

Science Journals Connector (OSTI)

We show for the Ising model that it is possible to construct a discrete time stochastic model analogous to the Langevin equation that incorporates an arbitrary amount of damping. It is shown to give the correct equilibrium statistics and is then used to investigate nonequilibrium phenomena, in particular, magnetic avalanches. The value of damping can greatly alter the shape of hysteresis loops, and for small damping and high disorder, the morphology of large avalanches can be drastically affected. Small damping also alters the size distribution of avalanches at criticality.

J. M. Deutsch and A. Berger

2008-03-28T23:59:59.000Z

148

CSAW: a dynamical model of protein folding  

E-Print Network (OSTI)

CSAW (conditioned self-avoiding walk) is a model of protein folding that combines SAW (self-avoiding walk) with Monte-Carlo. It simulates the Brownian motion of a chain molecule in the presence of interactions, both among chain residues, and with the environment. In a first model that includes the hydrophobic effect and hydrogen bonding, a chain of 30 residues folds into a native state with stable secondary and tertiary structures. The process starts with a rapid collapse into an intermediate "molten globule", which slowly decays into the native state afer a relatively long quiescent period. The behavior of the radius of gyration mimics experimental data.

Kerson Huang

2006-01-12T23:59:59.000Z

149

Clustering properties of dynamical dark energy models  

SciTech Connect

We provide a generic but physically clear discussion of the clustering properties of dark energy models. We explicitly show that in quintessence-type models the dark energy fluctuations, on scales smaller than the Hubble radius, are of the order of the perturbations to the Newtonian gravitational potential, hence necessarily small on cosmological scales. Moreover, comparable fluctuations are associated with different gauge choices. We also demonstrate that the often used homogeneous approximation is unrealistic, and that the so-called dark energy mutation is a trivial artifact of an effective, single fluid description. Finally, we discuss the particular case where the dark energy fluid is nonminimally coupled to dark matter.

Avelino, P. P.; Beca, L. M. G. [Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Martins, C. J. A. P. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas s/n, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2008-05-15T23:59:59.000Z

150

Radionuclide release rates from spent fuel for performance assessment modeling  

SciTech Connect

In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments.

Curtis, D.B.

1994-11-01T23:59:59.000Z

151

Assessment of traumatic brain injury degree in animal model  

Science Journals Connector (OSTI)

AbstractObjective To establish stable and controllable brain injury with accurate degree and good repeatability in rat model. Methods Controlled cortical impact (CCI) device was used to prepare for the rat brain injury model by the impact head of different model (Group A No. 4, Group B No. 5, Group C No. 6) and the impact depth (Group A: 1.5–2.0 mm, Group B: 2.5–3.0 mm, Group C: 3.5–4.0 mm) with impact time of 0.1 s and impact velocity of 2.5 m/s. Twelve rats with three months of age were used in each group (the impact depth of every two rats was added 1 mm respectively). After modeling for 1 h, magnetic resonance imaging (MRI) was received and brain histopathology was observed to assess degree of injury by model parameters of three groups. Results After modeling of Group A, MRI showed that the cortex structure was damaged with a small amount of bleeding in center and mild edema around, and the total volume of injury was (28.69±4.94) mm3. Pathology revealed the injury was confined to the superficial cortical with mild edema of nerve cell, which was assessed as mild cerebral contusion. While after modeling, MRI of Group B showed that the structure of cortex and medulla were damaged simultaneously and extended to cerebral nuclei zone, with 4 cases of hematoma in the center and larger edema range around, and the total volume of injury was (78.38±9.28) mm3. Pathology revealed the injury range was reached nuclei zone, with swell of nerve cell and mitochondria, which was assessed to moderate cerebral contusion. After modeling of Group C, MRI showed that extensive tissue injury was appeared in cortex and medulla and deep nuclei, with 9 cases of hematoma and large edema signal of surrounding tissue T2WI, while in 5 cases, lateral nucleus of injury signal was increased, and the total volume of injury was (135.89±24.80) mm3. Pathology revealed the deep cerebral nuclei was damaged, with the disappearance of neuronal structure and vacuolization of mitochondria, which was assessed as severe cerebral contusion. MRI changes were consistent with pathological changes in three groups of model, and the injury range was significantly different (Pbrain injury model, which overcomes the randomness in previous injury model and possesses highly unity in iconography and pathology changes. This can provide quantitative modeling reference for clinical research.

Jian-Qiang Chen; Cheng-Cheng Zhang; Hong Lu; Wei Wang

2014-01-01T23:59:59.000Z

152

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-Print Network (OSTI)

In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

Raymond E. Goldstein

2014-09-08T23:59:59.000Z

153

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-Print Network (OSTI)

In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these re...

Goldstein, Raymond E

2014-01-01T23:59:59.000Z

154

The Community Surface Dynamics Modeling System: Experiences on Building a Collaborative Modeling Platform  

E-Print Network (OSTI)

The Community Surface Dynamics Modeling System: Experiences on Building a Collaborative Modeling VOLUNTEERISM MANY DEVELOPERS Grand Challenge: Building a Toolbox of Component Models with guidance and input Members and Governance · Tools for Collaboration 1) CSDMS Wiki 2) CSDMS Modeling Tool · Strategies

Wright, Dawn Jeannine

155

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations  

E-Print Network (OSTI)

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations J 2004) An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation

Brenner, Donald W.

156

E-Print Network 3.0 - assessment modeling productivity Sample...  

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

Summary: models is suggested as a means of improving the impact assessment phase of LCA. Keywords: Life Cycle... assessment methodologies 1. These early inventories would...

157

Solar Resource Assessment: Databases, Measurements, Models, and Information Sources (Fact Sheet)  

SciTech Connect

Fact sheet for Solar Resource Assessment Workshop, Denver CO, Oct 29, 2008: ?Solar Resource Assessment Databases, Measurements, Models, and Information Sources

Not Available

2008-10-01T23:59:59.000Z

158

A Dynamical Model of Plasma Turbulence in the Solar Wind  

E-Print Network (OSTI)

A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfven waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfven waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent casca...

Howes, G G

2015-01-01T23:59:59.000Z

159

Modeling Dynamic Landscapes in Open Source GIS  

E-Print Network (OSTI)

differencing, per-cell statistics: core, envelope, rate of change Space-Time voxel model V o lu m e s S u rf a c e s L in e s 2011 2004 1999 Helena Mitasova, NCSU DEM processing Series of point clouds interpolated to 0.3m-1m DEMs Systematic errors... to Doug Newcomb and Hope Morgan for sharing the data RTKGPS 2001 Lidar 0.2m lower Helena Mitasova, NCSU Nags Head Raster-based analysis Core surface z-min for each cell Envelope surface z-max for each cell Shoreline band: defined by shoreline from core...

Mitasova, Helena

2013-11-20T23:59:59.000Z

160

Wind Energy Applications of Unified and Dynamic Turbulence Models  

E-Print Network (OSTI)

Wind Energy Applications of Unified and Dynamic Turbulence Models Stefan Heinz and Harish Gopalan applicable as a low cost alternative. 1 Introduction There is a growing interest in using wind energy suggests the possibility of providing 20% of the electricity in the U.S. by wind energy in 2030

Heinz, Stefan

Note: This page contains sample records for the topic "dynamics models assessing" 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

A Bayesian Dynamic Model for Influenza Surveillance Paola Sebastiani  

E-Print Network (OSTI)

by the increasing number of outbreaks caused by the H5N1 bird-flu strain [10]. Because influenza viruses changeA Bayesian Dynamic Model for Influenza Surveillance Paola Sebastiani Kenneth D Mandl Peter, the growing fear of an influenza pandemic and the recent shortage of flu vaccine highlight the need

Szolovits, Peter

162

Multiscale modeling of polystyrene dynamics in different environments  

E-Print Network (OSTI)

Multiscale modeling of polystyrene dynamics in different environments Qi Sun1 , Florence Pon1 simulations can address not only the average properties of the system but also the distribution over any component in their neighborhood and vice versa. The simulation temperature of 450 K is chosen to be above

Faller, Roland

163

A Model for Dynamic Reconfiguration in Service-oriented Architectures  

E-Print Network (OSTI)

A Model for Dynamic Reconfiguration in Service-oriented Architectures Jos´e Luiz Fiadeiro1 and Ant of service-oriented applications goes be- yond what is currently addressed by existing architecture of service-oriented applications. 1 Introduction Several architectural aspects arise from service-oriented

Lopes, Antónia

164

Dynamic Modeling and Recipe Optimization of Polyether Polyol Processes  

E-Print Network (OSTI)

Dynamic Modeling and Recipe Optimization of Polyether Polyol Processes Fall 2012 EWO Meeting Yisu Monomer Reactor Basic procedures Starters are first mixed with catalyst in the liquid phase Alkylene oxides in the liquid phase are fed in controlled rates The reactor temperature is controlled by the heat

Grossmann, Ignacio E.

165

FRW Cosmological model with Modified Chaplygin Gas and Dynamical System  

E-Print Network (OSTI)

The Friedmann-Robertson-Walker(FRW) model with dynamical Dark Energy(DE) in the form of modified Chaplygin gas(MCG) has been investigated. The evolution equations are reduced to an autonomous system on the two dimensional phase plane and it can be interpreted as the motion of the particle in an one dimensional potential.

Nairwita Mazumder; Ritabrata Biswas; Subenoy Chakraborty

2011-06-23T23:59:59.000Z

166

Reverse Audio Engineering: Model-Based Inversion of Dynamic Range  

E-Print Network (OSTI)

1 Reverse Audio Engineering: Model-Based Inversion of Dynamic Range Compression Stanislaw Gorlow, Graduate Student Member, IEEE and Joshua D. Reiss, Member, IEEE Abstract--Reverse audio engineering so far, reverse audio engineering. I. INTRODUCTION SOUND or audio engineering is an established discipline

167

Developing a Modeling Framework for Assessing Population Impacts of  

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

Developing a Modeling Framework for Assessing Population Impacts of Developing a Modeling Framework for Assessing Population Impacts of Residential Air Quality Policies Speaker(s): Jennifer Logue Date: November 13, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Brett Singer People spend the majority of their time in residences and the health burden of indoor air is significant. However, the definitions of "acceptable" and "good" indoor air quality (IAQ), and the most effective, energy efficient methods for achieving various levels of IAQ are still matters of research and debate. Current ventilation standards focus on minimum requirements for overall and mechanically provided ventilation rates, and vented combustion equipment, and require only the installation of kitchen and bath exhaust fans for source control. These standards generally are

168

Dynamic volume vs respiratory correlated 4DCT for motion assessment in radiation therapy simulation  

SciTech Connect

Purpose: Conventional (i.e., respiratory-correlated) 4DCT exploits the repetitive nature of breathing to provide an estimate of motion; however, it has limitations due to binning artifacts and irregular breathing in actual patient breathing patterns. The aim of this work was to evaluate the accuracy and image quality of a dynamic volume, CT approach (4D{sub vol}) using a 320-slice CT scanner to minimize these limitations, wherein entire image volumes are acquired dynamically without couch movement. This will be compared to the conventional respiratory-correlated 4DCT approach (RCCT). Methods: 4D{sub vol} CT was performed and characterized on an in-house, programmable respiratory motion phantom containing multiple geometric and morphological ''tumor'' objects over a range of regular and irregular patient breathing traces obtained from 3D fluoroscopy and compared to RCCT. The accuracy of volumetric capture and breathing displacement were evaluated and compared with the ground truth values and with the results reported using RCCT. A motion model was investigated to validate the number of motion samples needed to obtain accurate motion probability density functions (PDF). The impact of 4D image quality on this accuracy was then investigated. Dose measurements using volumetric and conventional scan techniques were also performed and compared. Results: Both conventional and dynamic volume 4DCT methods were capable of estimating the programmed displacement of sinusoidal motion, but patient breathing is known to not be regular, and obvious differences were seen for realistic, irregular motion. The mean RCCT amplitude error averaged at 4 mm (max. 7.8 mm) whereas the 4D{sub vol} CT error stayed below 0.5 mm. Similarly, the average absolute volume error was lower with 4D{sub vol} CT. Under irregular breathing, the 4D{sub vol} CT method provides a close description of the motion PDF (cross-correlation 0.99) and is able to track each object, whereas the RCCT method results in a significantly different PDF from the ground truth, especially for smaller tumors (cross-correlation ranging between 0.04 and 0.69). For the protocols studied, the dose measurements were higher in the 4D{sub vol} CT method (40%), but it was shown that significant mAs reductions can be achieved by a factor of 4-5 while maintaining image quality and accuracy. Conclusions: 4D{sub vol} CT using a scanner with a large cone-angle is a promising alternative for improving the accuracy with which respiration-induced motion can be characterized, particularly for patients with irregular breathing motion. This approach also generates 4DCT image data with a reduced total scan time compared to a RCCT scan, without the need for image binning or external respiration signals within the 16 cm scan length. Scan dose can be made comparable to RCCT by optimization of the scan parameters. In addition, it provides the possibility of measuring breathing motion for more than one breathing cycle to assess stability and obtain a more accurate motion PDF, which is currently not feasible with the conventional RCCT approach.

Coolens, Catherine; Bracken, John; Driscoll, Brandon; Hope, Andrew; Jaffray, David [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada) and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

2012-05-15T23:59:59.000Z

169

A residence-time-based transport approach for the groundwater pathway in performance assessment models  

Science Journals Connector (OSTI)

This paper presents the theoretical development and numerical implementation of a new modeling approach for representing the groundwater pathway in risk assessment or performance assessment model of a contaminant transport system. The model developed ... Keywords: Groundwater pathway, Mixing model, Performance assessment, Residence time distribution

Bruce A. Robinson; Shaoping Chu

2013-03-01T23:59:59.000Z

170

Modeling issues associated with production reactor safety assessment  

SciTech Connect

This paper describes several Probabilistic Safety Assessment (PSA) modeling issues that are related to the unique design and operation of the production reactors. The identification of initiating events and determination of a set of success criteria for the production reactors is of concern because of their unique design. The modeling of accident recovery must take into account the unique operation of these reactors. Finally, a more thorough search and evaluation of common-cause events is required to account for combinations of unique design features and operation that might otherwise not be included in the PSA. It is expected that most of these modeling issues also would be encountered when modeling some of the other more unique reactor and nonreactor facilities that are part of the DOE nuclear materials production complex. 9 refs., 2 figs.

Stack, D.W. (Los Alamos National Lab., NM (USA)); Thomas, W.R. (Science and Engineering Associates, Inc., Albuquerque, NM (USA))

1990-01-01T23:59:59.000Z

171

PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment  

SciTech Connect

Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

2012-08-31T23:59:59.000Z

172

Model equations in rarefied gas dynamics: Viscous-slip and thermal-slip coefficients  

E-Print Network (OSTI)

Model equations in rarefied gas dynamics: Viscous-slip and thermal-slip coefficients C. E. Siewert-slip and the thermal-slip coefficients in rarefied gas dynamics. More specifically, the BGK model, the S model In reviewing numerous papers devoted to model equa- tions in rarefied gas dynamics, we have found no definitive

Siewert, Charles E.

173

Coupling Lattice Boltzmann and Molecular Dynamics models for dense fluids  

E-Print Network (OSTI)

We propose a hybrid model, coupling Lattice Boltzmann and Molecular Dynamics models, for the simulation of dense fluids. Time and length scales are decoupled by using an iterative Schwarz domain decomposition algorithm. The MD and LB formulations communicate via the exchange of velocities and velocity gradients at the interface. We validate the present LB-MD model in simulations of flows of liquid argon past and through a carbon nanotube. Comparisons with existing hybrid algorithms and with reference MD solutions demonstrate the validity of the present approach.

A. Dupuis; E. M. Kotsalis; P. Koumoutsakos

2006-10-27T23:59:59.000Z

174

CliCrop: a Crop Water-Stress and Irrigation Demand Model for an Integrated Global Assessment Model Approach  

E-Print Network (OSTI)

This paper describes the use of the CliCrop model in the context of climate change general assessment

Fant, C.A.

175

Methods for Developing Emissions Scenarios for Integrated Assessment Models  

SciTech Connect

The overall objective of this research was to contribute data and methods to support the future development of new emissions scenarios for integrated assessment of climate change. Specifically, this research had two main objectives: 1. Use historical data on economic growth and energy efficiency changes, and develop probability density functions (PDFs) for the appropriate parameters for two or three commonly used integrated assessment models. 2. Using the parameter distributions developed through the first task and previous work, we will develop methods of designing multi-gas emission scenarios that usefully span the joint uncertainty space in a small number of scenarios. Results on the autonomous energy efficiency improvement (AEEI) parameter are summarized, an uncertainty analysis of elasticities of substitution is described, and the probabilistic emissions scenario approach is presented.

Prinn, Ronald [MIT; Webster, Mort [MIT

2007-08-20T23:59:59.000Z

176

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. part I: Aerodynamics  

Science Journals Connector (OSTI)

Abstract The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative concepts in this context. Vertical axis wind turbines (VAWTs) are one promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess their technical feasibility. A comprehensive review detailing the areas of engineering expertise utilised in developing an understanding of the coupled dynamics of floating \\{VAWTs\\} has been developed through a series of articles. This first article details the aerodynamic modelling of VAWTs, providing a review of available models, discussing their applicability to floating \\{VAWTs\\} and current implementations by researchers in this field. A concise comparison between conventional horizontal axis wind turbines and \\{VAWTs\\} is also presented, outlining the advantages and disadvantages of these technologies for the floating wind industry. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Andrew Shires; Maurizio Collu

2014-01-01T23:59:59.000Z

177

Coping with uncertain dynamics in visual tracking : redundant state models and discrete search methods  

E-Print Network (OSTI)

A model of the world dynamics is a vital part of any tracking algorithm. The observed world can exhibit multiple complex dynamics at different spatio-temporal scales. Faithfully modeling all motion constraints in a ...

Taycher, Leonid

2006-01-01T23:59:59.000Z

178

A Groundwater Dynamic Simulation Model: Application to the Upper San Pedro Basin  

E-Print Network (OSTI)

A Groundwater Dynamic Simulation Model: Application to the Upper San Pedro Basin Report Prepared by using tools such as tracers to determine groundwater travel times and this dynamic simulation modeling

Fay, Noah

179

An Inspector's Assessment of the New Model Safeguards Approach for Enrichment Plants  

SciTech Connect

This conference paper assesses the changes that are being made to the Model Safeguards Approach for Gas Centrifuge Enrichment Plants.

Curtis, Michael M.

2007-07-31T23:59:59.000Z

180

Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Lessons Learned from Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Technical Report NREL/TP-540-39446 February 2006 Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Prepared under Task Nos. HS04.2000 and HS06.1002 Technical Report NREL/TP-540-39446 February 2006 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute * Battelle Contract No. DE-AC36-99-GO10337 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any

Note: This page contains sample records for the topic "dynamics models assessing" 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

Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment  

SciTech Connect

Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application. It is possible to have confidence in the predictions of many of the existing models because of their fundamental physical and chemical mechanistic underpinnings and the extensive work already done to compare model predictions and empirical observations. The working group recommends that modeling tools be applied for benchmarking PBT/POPs according to exposure-to-emissions relationships, and that modeling tools be used to interpret emissions and monitoring data. The further development of models that couple fate, long-range transport, and bioaccumulation should be fostered, especially models that will allow time trends to be scientifically addressed in the risk profile.

Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

2008-11-01T23:59:59.000Z

182

Dynamical Reduction Models: present status and future developments  

E-Print Network (OSTI)

We review the major achievements of the dynamical reduction program, showing why and how it provides a unified, consistent description of physical phenomena, from the microscopic quantum domain to the macroscopic classical one. We discuss the difficulties in generalizing the existing models in order to comprise also relativistic quantum field theories. We point out possible future lines of research, ranging from mathematical physics to phenomenology.

A. Bassi

2007-02-08T23:59:59.000Z

183

Examining emissions policy issues with an integrated assessment model  

SciTech Connect

In the policy analysis process of asking ``What if'' questions, there is considerable advantage in the analyst being able to address the questions directly rather than sending the questions to scientists in particular disciplines and awaiting answers. Obviously the former option is likely to produce speedier results than the latter; in addition, the questions can be easily modified as the issues change or become more focused. The primary potential shortcoming of an analyst addressing questions that may be beyond his or her particular expertise is that the policy analyst may not understand the limitations of the analysis. Here the author briefly describes a peer-reviewed integrated assessment model that can be exercised within minutes in a desktop environment, discuss some of the advantages and limitations of the approach, and exercise portions of the model to compare with observations. Because of the nature of the conference at which this paper is being presented, the discussion focuses on the air pollution modeling components of the integrated assessment.

Shannon, J. D.

1999-10-21T23:59:59.000Z

184

Modeling biofuel expansion effects on land use change dynamics  

Science Journals Connector (OSTI)

Increasing demand for crop-based biofuels, in addition to other human drivers of land use, induces direct and indirect land use changes (LUC). Our system dynamics tool is intended to complement existing LUC modeling approaches and to improve the understanding of global LUC drivers and dynamics by allowing examination of global LUC under diverse scenarios and varying model assumptions. We report on a small subset of such analyses. This model provides insights into the drivers and dynamic interactions of LUC (e.g., dietary choices and biofuel policy) and is not intended to assert improvement in numerical results relative to other works.Demand for food commodities are mostly met in high food and high crop-based biofuel demand scenarios, but cropland must expand substantially. Meeting roughly 25% of global transportation fuel demand by 2050 with biofuels requires >2 times the land used to meet food demands under a presumed 40% increase in per capita food demand. In comparison, the high food demand scenario requires greater pastureland for meat production, leading to larger overall expansion into forest and grassland. Our results indicate that, in all scenarios, there is a potential for supply shortfalls, and associated upward pressure on prices, of food commodities requiring higher land use intensity (e.g., beef) which biofuels could exacerbate.

Ethan Warner; Daniel Inman; Benjamin Kunstman; Brian Bush; Laura Vimmerstedt; Steve Peterson; Jordan Macknick; Yimin Zhang

2013-01-01T23:59:59.000Z

185

Best practices for system dynamics model design and construction with powersim studio.  

SciTech Connect

This guide addresses software quality in the construction of Powersim{reg_sign} Studio 8 system dynamics simulation models. It is the result of almost ten years of experience with the Powersim suite of system dynamics modeling tools (Constructor and earlier Studio versions). It is a guide that proposes a common look and feel for the construction of Powersim Studio system dynamics models.

Malczynski, Leonard A.

2011-06-01T23:59:59.000Z

186

Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models  

E-Print Network (OSTI)

Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models (2004)). Large multi­city studies such as `Air pollution and health: a European approach' (APHEA across a number of US and European cities. Short­term e#ects of air pollution on health are estimated

Bath, University of

187

A preliminary study to Assess Model Uncertainties in Fluid Flows  

SciTech Connect

The goal of this study is to assess the impact of various flow models for a simplified primary coolant loop of a light water nuclear reactor. The various fluid flow models are based on the Euler equations with an additional friction term, gravity term, momentum source, and energy source. The geometric model is purposefully chosen simple and consists of a one-dimensional (1D) loop system in order to focus the study on the validity of various fluid flow approximations. The 1D loop system is represented by a rectangle; the fluid is heated up along one of the vertical legs and cooled down along the opposite leg. A pressurizer and a pump are included in the horizontal legs. The amount of energy transferred and removed from the system is equal in absolute value along the two vertical legs. The various fluid flow approximations are compressible vs. incompressible, and complete momentum equation vs. Darcy’s approximation. The ultimate goal is to compute the fluid flow models’ uncertainties and, if possible, to generate validity ranges for these models when applied to reactor analysis. We also limit this study to single phase flows with low-Mach numbers. As a result, sound waves carry a very small amount of energy in this particular case. A standard finite volume method is used for the spatial discretization of the system.

Marc Oliver Delchini; Jean C. Ragusa

2009-09-01T23:59:59.000Z

188

User Guide for PV Dynamic Model Simulation Written on PSCAD Platform  

SciTech Connect

This document describes the dynamic photovoltaic model developed by the National Renewable Energy Laboratory and is intended as a guide for users of these models.

Muljadi, E.; Singh, M.; Gevorgian, V.

2014-11-01T23:59:59.000Z

189

A Nonlocal Peridynamic Plasticity Model for the Dynamic Flow and Fracture of Concrete.  

SciTech Connect

A nonlocal, ordinary peridynamic constitutive model is formulated to numerically simulate the pressure-dependent flow and fracture of heterogeneous, quasi-brittle ma- terials, such as concrete. Classical mechanics and traditional computational modeling methods do not accurately model the distributed fracture observed within this family of materials. The peridynamic horizon, or range of influence, provides a characteristic length to the continuum and limits localization of fracture. Scaling laws are derived to relate the parameters of peridynamic constitutive model to the parameters of the classical Drucker-Prager plasticity model. Thermodynamic analysis of associated and non-associated plastic flow is performed. An implicit integration algorithm is formu- lated to calculate the accumulated plastic bond extension and force state. The gov- erning equations are linearized and the simulation of the quasi-static compression of a cylinder is compared to the classical theory. A dissipation-based peridynamic bond failure criteria is implemented to model fracture and the splitting of a concrete cylinder is numerically simulated. Finally, calculation of the impact and spallation of a con- crete structure is performed to assess the suitability of the material and failure models for simulating concrete during dynamic loadings. The peridynamic model is found to accurately simulate the inelastic deformation and fracture behavior of concrete during compression, splitting, and dynamically induced spall. The work expands the types of materials that can be modeled using peridynamics. A multi-scale methodology for simulating concrete to be used in conjunction with the plasticity model is presented. The work was funded by LDRD 158806.

Vogler, Tracy; Lammi, Christopher James

2014-10-01T23:59:59.000Z

190

THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL  

SciTech Connect

The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table.

G. Saulnier and W. Statham

2006-04-16T23:59:59.000Z

191

Modeling and Quantification of Team Performance in Human Reliability Analysis for Probabilistic Risk Assessment  

SciTech Connect

Probabilistic Risk Assessment (PRA) and Human Reliability Assessment (HRA) are important technical contributors to the United States (U.S.) Nuclear Regulatory Commission’s (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial NPPs in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. There are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating HEPs. This paper describes research that has the objective to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.

Jeffrey C. JOe; Ronald L. Boring

2014-06-01T23:59:59.000Z

192

Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)  

SciTech Connect

Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into a dynamic extrusion experiment. The dynamic extrusion response of copper (three different grain sizes) and tantalum spheres were simulated with MESA, an explicit, 2-D Eulerian continuum mechanics hydrocode and compared with experimental data. The experimental data consisted of high-speed images of the extrusion process, recovered extruded samples, and post test metallography. The hydrocode was developed to predict large-strain and high-strain-rate loading problems. Some of the features of the features of MESA include a high-order advection algorithm, a material interface tracking scheme and a van Leer monotonic advection-limiting. The Mechanical Threshold Stress (MTS) model was utilized to evolve the flow stress as a function of strain, strain rate and temperature for copper and tantalum. Plastic strains exceeding 300% were predicted in the extrusion of copper at 400 m/s, while plastic strains exceeding 800% were predicted for Ta. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate were made. Additionally, predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the copper during the extrusion process) were compared with the orientation imaging microscopy measurements. Finally, comparisons between the calculated and measured influence of the initial texture on the dynamic extrusion response of tantalum was performed.

Burkett, Michael W [Los Alamos National Laboratory; Clancy, Sean P [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

193

A spectral transform dynamical core option within the Community Atmosphere Model (CAM4)  

SciTech Connect

A spectral transform dynamical core with an 85 spectral truncation resolution (T85) within the Community Atmosphere Model (CAM), version 4, is evaluated within the recently released Community Earth System Model, version 1.0 (CESM) global climate model. The spectral dynamical core option provides a well-known base within the climate model community from which to assess climate behavior and statistics, and its relative computational efficiency for smaller computing platforms allows it to be extended to perform climate length simulations using high-resolution configurations in the near term. To establish the characteristics of the CAM4 T85, an ensemble of simulations covering the present day observational period using forced sea surface temperatures and prescribed sea-ice extent are evaluated. Overall, the T85 ensemble attributes and biases are similar to a companion ensemble of simulations using the one degree finite volume (FV1) dynamical core, relative to observed and model derived datasets. Notable improvements with T85 compared to FV1 include the representation of wintertime Arctic sea level pressure and summer precipitation over the Western Indian subcontinent. The mean and spatial patterns of the land surface temperature trends over the AMIP period are generally well simulated with the T85 ensemble relative to observations, however the model is not able to capture the extent nor magnitude of changes in temperature extremes over the boreal summer, where the changes are most dramatic. Biases in the wintertime Arctic surface temperature and annual mean surface stress fields persist with T85 as with the CAM3 version of T85.

Evans, Katherine J [ORNL; Mahajan, Salil [ORNL; Branstetter, Marcia L [ORNL; McClean, Julie L. [Scripps Institute of Oceanography; Caron, Julie M. [National Center for Atmospheric Research (NCAR); Maltrud, Matthew E. [Los Alamos National Laboratory (LANL); Hack, James J [ORNL; Bader, David C [ORNL; Neale, Rich [National Center for Atmospheric Research (NCAR)

2014-01-01T23:59:59.000Z

194

Dynamic ModelingDynamic Modeling the Electric Power Networkthe Electric Power Network  

E-Print Network (OSTI)

criteria to enter the wholesale market DEREGULATION PROCESS: FERC's Order 888 mandated the wheeling at the National Energy Modeling System/Annual Energy Outlook Conference, Washington, DC, March 10, 2003] #12

Oro, Daniel

195

Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance Models  

E-Print Network (OSTI)

ARTICLES Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance metabolism with dynamic mass balances on key extracellular species. Model-based dynamic optimization concentration profiles, and the final batch time are treated as decision variables in the dynamic optimization

Mountziaris, T. J.

196

Dynamics of popstar record sales on phonographic market -- stochastic model  

E-Print Network (OSTI)

We investigate weekly record sales of the world's most popular 30 artists (2003-2013). Time series of sales have non-trivial kind of memory (anticorrelations, strong seasonality and constant autocorrelation decay within 120 weeks). Amount of artists record sales are usually the highest in the first week after premiere of their brand new records and then decrease to fluctuate around zero till next album release. We model such a behavior by discrete mean-reverting geometric jump diffusion (MRGJD) and Markov regime switching mechanism (MRS) between the base and the promotion regimes. We can built up the evidence through such a toy model that quantifies linear and nonlinear dynamical components (with stationary and nonstationary parameters set), and measure local divergence of the system with collective behavior phenomena. We find special kind of disagreement between model and data for Christmas time due to unusual shopping behavior. Analogies to earthquakes, product life-cycles, and energy markets will also be d...

Jarynowski, Amdrzej

2013-01-01T23:59:59.000Z

197

Dynamic Decision Making for Graphical Models Applied to Oil Exploration  

E-Print Network (OSTI)

We present a framework for sequential decision making in problems described by graphical models. The setting is given by dependent discrete random variables with associated costs or revenues. In our examples, the dependent variables are the potential outcomes (oil, gas or dry) when drilling a petroleum well. The goal is to develop an optimal selection strategy that incorporates a chosen utility function within an approximated dynamic programming scheme. We propose and compare different approximations, from simple heuristics to more complex iterative schemes, and we discuss their computational properties. We apply our strategies to oil exploration over multiple prospects modeled by a directed acyclic graph, and to a reservoir drilling decision problem modeled by a Markov random field. The results show that the suggested strategies clearly improve the simpler intuitive constructions, and this is useful when selecting exploration policies.

Martinelli, Gabriele; Hauge, Ragnar

2012-01-01T23:59:59.000Z

198

Dynamic validated model of a DFIG wind turbine  

Science Journals Connector (OSTI)

This paper presents the development and qualitative validation of a doubly-fed induction generator (DFIG) wind turbine model that is represented in terms of behaviour equations of each of the subsystems, mainly the turbine rotor, the drive train, the induction generator, the power converters and associated control systems and a protection system. Simulation results obtained from the models are compared to the field measurement data in a qualitative manner due to rotor wake and lack of ability of a single anemometer for adequate measurement of wind speed acting on the large surface of the rotor. It is concluded that the model is reasonably accurate and can hence be used for representing wind turbines in power system dynamics simulations.

Md. Ayaz Chowdhury; Nasser Hosseinzadeh; Weixiang Shen

2014-01-01T23:59:59.000Z

199

Explorations in combining cognitive models of individuals and system dynamics models of groups.  

SciTech Connect

This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

Backus, George A.

2008-07-01T23:59:59.000Z

200

An integrated environmental modeling framework for performing Quantitative Microbial Risk Assessments  

Science Journals Connector (OSTI)

Standardized methods are often used to assess the likelihood of a human-health effect from exposure to a specified hazard, and inform opinions and decisions about risk management and communication. A Quantitative Microbial Risk Assessment (QMRA) is specifically ... Keywords: Integrated environmental modeling, Manure, Pathogens, QMRA, Risk assessment, Watershed modeling

Gene Whelan, Keewook Kim, Mitch A. Pelton, Jeffrey A. Soller, Karl J. Castleton, Marirosa Molina, Yakov Pachepsky, Richard Zepp

2014-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Models for source term, flow, transport and dose assessment in NRC`s Iterative Performance Assessment, Phase 2  

SciTech Connect

The core consequence modules for the recently completed Phase 2 Iterative Performance Assessment (IPA) of the Yucca Mountain repository for high-level nuclear waste depend on models for releases from the engineered barrier system (source term), flow of liquid and gas, transport of radionuclides in the geosphere and assessment of dose to target populations. The source term model includes temperature and moisture phenomena in the near-field environment, general, pitting and crevice corrosion, contact of the waste form by water, dissolution and oxidation of the waste form, and transport of dissolved and gaseous radionuclides from the waste package by advection and diffusion. The liquid flow and transport models describe water flow through fractures and matrix in both the unsaturated and saturated zones. Models for flow of gas and transport of {sup 14}CO{sub 2} released from the engineered barrier system to the atmosphere take into account repository heat and the geothermal gradient. The dose assessment model calculates doses to a regional population and a farm family for an assumed reference biosphere in the vicinity of the repository. The Phase 2 IPA led to a number of suggestions for model improvement: (1) improve the ability of the models to include spatial and temporal variability in the parameters; (2) improve the coupling among processes, especially the effects of changing environments in the waste packages; (3) develop more mechanistic models, but abstracted for use in total system performance assessment; and (4) use more site specific parameters, especially for the dose assessments.

McCartin, T.; Codell, R.; Neel, R.; Ford, W.; Wescott, R.; Bradbury, J. [Nuclear Regulatory Commission, Washington, DC (United States); Sagar, B.; Walton, J. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

1994-12-31T23:59:59.000Z

202

Transportation System Risk Assessment (TSRA) bounding release model  

SciTech Connect

Transportation System Risk Assessments (TSRAs) document the compliance of proposed shipments of nuclear components with applicable federal regulations as well as the associated risks involved. If a relatively simple bounding analysis can show that the consequences resulting from a worst case scenario are acceptably low, a more time intensive and costly risk analysis can be avoided. Therefore, a bounding release FORTRAN model has been developed to determine the consequences of a worst case non-criticality transportation accident. The consequences of three conservative bounding accidents are determined by the model: (1) direct radiation exposure, (2) airborne release of radiological and/or hazardous solid material, and (3) release of radiological and/or hazardous solid material into a waterway and subsequent uptake by an individual through drinking water. Program output includes the direct radiation exposure (mrem), maximum downwind concentration (mg/m{sup 3}), radiation dose (mrem) received as a result of the postulated airborne release of radiological material, intake (mg) due to inhalation, radiation dose (mrem) received by an individual resulting from a release of radiological material into a waterway and uptake into drinking water, and uptake (mg) due to ingestion. This report documents the methodologies and correlations used in the numerical model to perform the bounding consequence calculations.

Anderson, J.C.

1997-10-01T23:59:59.000Z

203

Large scale molecular dynamics modeling of materials fabrication processes  

SciTech Connect

An atomistic molecular dynamics model of materials fabrication processes is presented. Several material removal processes are shown to be within the domain of this simulation method. Results are presented for orthogonal cutting of copper and silicon and for crack propagation in silica glass. Both copper and silicon show ductile behavior, but the atomistic mechanisms that allow this behavior are significantly different in the two cases. The copper chip remains crystalline while the silicon chip transforms into an amorphous state. The critical stress for crack propagation in silica glass was found to be in reasonable agreement with experiment and a novel stick-slip phenomenon was observed.

Belak, J.; Glosli, J.N.; Boercker, D.B.; Stowers, I.F.

1994-02-01T23:59:59.000Z

204

Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving on a Slope 1 Dynamic Modeling and Adaptive Neural-Fuzzy Control for  

E-Print Network (OSTI)

robots [7]. A robust fuzzy logic controller was devised for a robotic manipulator with uncertainties [8Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving on a Slope 1 Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving

Li, Yangmin

205

MODELLING RADIOIODINE DYNAMICS Modelling the Dynamics of Radioiodine in Dairy Cows  

E-Print Network (OSTI)

Department of Physiology & Environmental Science University of Nottingham Sutton Bonington LE12 5RD UK G for significant fecal excretion of radioiodine. The5 model is used to consider the effect of dietary stable iodine of iodine, in particular I-131, are important components in fallout from2 nuclear accidents

Crout, Neil

206

Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network  

E-Print Network (OSTI)

DS-06-1351 Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network Tomás dynamics of gasoline engines during transient operation. With a collection of input-output data measured;Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network I. INTRODUCTION

Johansen, Tor Arne

207

Predictive Model for Environmental Assessment in Additive Manufacturing Process  

Science Journals Connector (OSTI)

Abstract Additive Manufacturing is an innovative way to produce parts. However its environmental impact is unknown. To ensure the development of additive manufacturing processes it seems important to develop the concept of DFSAM (Design for Sustainable Additive Manufacturing). In fact, one of the objectives of environmental sustainable manufacturing is to minimize the whole flux consumption (electricity, material and fluids) during manufacturing step. To achieve this goal, it is interesting to get a predictive model of consumptions, integrated in the design step, allowing to evaluate the product's environmental impact during the manufacturing step. This paper presents a new methodology for electric, fluids and raw material consumptions assessment for additive manufacturing processes, in particular for a direct metal deposition process. The methodology will help engineers to design parts optimized for additive manufacturing with an environmental point of view.

Florent Le Bourhis; Olivier Kerbrat; Lucas Dembinski; Jean-Yves Hascoet; Pascal Mognol

2014-01-01T23:59:59.000Z

208

Position Paper: A general framework for Dynamic Emulation Modelling in environmental problems  

Science Journals Connector (OSTI)

Emulation modelling is an effective way of overcoming the large computational burden associated with the process-based models traditionally adopted by the environmental modelling community. An emulator is a low-order, computationally efficient model ... Keywords: Dynamic emulation modelling, Metamodelling, Model complexity, Model reduction, Process-based models, Response surfaces

A. Castelletti; S. Galelli; M. Ratto; R. Soncini-Sessa; P. C. Young

2012-06-01T23:59:59.000Z

209

Designability, thermodynamic stability, and dynamics in protein folding: A lattice model study  

E-Print Network (OSTI)

Designability, thermodynamic stability, and dynamics in protein folding: A lattice model study Re October 1998 In the framework of a lattice-model study of protein folding, we investigate the interplay model. Lattice models have been widely used in the study of protein folding dynamics.2­8 The main

Levine, Alex J.

210

Comparative Studies of Clustering Techniques for Real-Time Dynamic Model Reduction  

E-Print Network (OSTI)

Dynamic model reduction in power systems is necessary for improving computational efficiency. Traditional model reduction using linearized models or offline analysis would not be adequate to capture power system dynamic behaviors, especially the new mix of intermittent generation and intelligent consumption makes the power system more dynamic and non-linear. Real-time dynamic model reduction emerges as an important need. This paper explores the use of clustering techniques to analyze real-time phasor measurements to determine generator groups and representative generators for dynamic model reduction. Two clustering techniques -- graph clustering and evolutionary clustering -- are studied in this paper. Various implementations of these techniques are compared and also compared with a previously developed Singular Value Decomposition (SVD)-based dynamic model reduction approach. Various methods exhibit different levels of accuracy when comparing the reduced model simulation against the original model. But some ...

Hogan, Emilie; Halappanavar, Mahantesh; Huang, Zhenyu; Lin, Guang; Lu, Shuai; Wang, Shaobu

2015-01-01T23:59:59.000Z

211

Dynamic Cost-Loss Ratio Decision-making Model with an Autocorrelated Climate Variable  

Science Journals Connector (OSTI)

A dynamic decision-making problem is considered involving the use of information about the autocorrelation of a climate variable. Specifically, an infinite horizon, discounted version of the dynamic cost-loss ratio model is treated, in which only ...

Richard W. Katz

1993-01-01T23:59:59.000Z

212

Dynamic Model of Hydrogen in GaN  

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

Dynamic Model of Hydrogen in GaN by S. M. Myers and A. F. Wright Motivation-Hydrogen is incorporated into p-type GaN during MOCVD growth, producing highly stable passivation of the Mg acceptors. Complete acceptor activation by thermal H release requires temperatures that threaten material integrity, prompting compromises in device processing. At lower temperatures, forward bias of p-n junctions or electron-beam irradiation produces a metastable, reversible activation without H release. To understand and control such effects, we are developing a mathematical model of H behavior wherein state energies from density-functional theory are employed in diffusion-reaction equations. Previously, we used the greatly simplifying assumptions of local equilibrium among states

213

Quasi-dynamic model for an organic Rankine cycle  

Science Journals Connector (OSTI)

Abstract When considering solar based thermal energy input to an organic Rankine cycle (ORC), intermittent nature of the heat input does not only adversely affect the power output but also it may prevent ORC to operate under steady state conditions. In order to identify reliability and efficiency of such systems, this paper presents a simplified transient modeling approach for an ORC operating under variable heat input. The approach considers that response of the system to heat input variations is mainly dictated by the evaporator. Consequently, overall system is assembled using dynamic models for the heat exchangers (evaporator and condenser) and static models of the pump and the expander. In addition, pressure drop within heat exchangers is neglected. The model is compared to benchmark numerical and experimental data showing that the underlying assumptions are reasonable for cases where thermal input varies in time. Furthermore, the model is studied on another configuration and mass flow rates of both the working fluid and hot water and hot water’s inlet temperature to the ORC unit are shown to have direct influence on the system’s response.

Musbaudeen O. Bamgbopa; Eray Uzgoren

2013-01-01T23:59:59.000Z

214

The Los Alamos dynamic radiation environment assimilation model (DREAM) for space weather specification and forecasting  

SciTech Connect

The Dynamic Radiation Environment Assimilation Model (DREAM) was developed at Los Alamos National Laboratory to assess, quantify, and predict the hazards from the natural space environment and the anthropogenic environment produced by high altitude nuclear explosions (HANE). DREAM was initially developed as a basic research activity to understand and predict the dynamics of the Earth's Van Allen radiation belts. It uses Kalman filter techniques to assimilate data from space environment instruments with a physics-based model of the radiation belts. DREAM can assimilate data from a variety of types of instruments and data with various levels of resolution and fidelity by assigning appropriate uncertainties to the observations. Data from any spacecraft orbit can be assimilated but DREAM was designed to function with as few as two spacecraft inputs: one from geosynchronous orbit and one from GPS orbit. With those inputs, DREAM can be used to predict the environment at any satellite in any orbit whether space environment data are available in those orbits or not. Even with very limited data input and relatively simple physics models, DREAM specifies the space environment in the radiation belts to a high level of accuracy. DREAM has been extensively tested and evaluated as we transition from research to operations. We report here on one set of test results in which we predict the environment in a highly-elliptical polar orbit. We also discuss long-duration reanalysis for spacecraft design, using DREAM for real-time operations, and prospects for 1-week forecasts of the radiation belt environment.

Reeves, Geoffrey D [Los Alamos National Laboratory; Friedel, Reiner H W [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

215

A comparative study of Lotka-Volterra and system dynamics models for simulation of technology industry dynamics  

E-Print Network (OSTI)

Scholars have developed a range of qualitative and quantitative models for generalizing the dynamics of technological innovation and identifying patterns of competition between rivals. This thesis compares two predominant ...

Ünver, Hakk? Özgür

2008-01-01T23:59:59.000Z

216

Ecosystem dynamics at six contrasting sites: a generic modelling study  

Science Journals Connector (OSTI)

A pelagic marine ecosystem simulation model ERSEM-2004, developed from the European Regional Seas Ecosystem Model (ERSEM II), is presented along with a parameter set applicable to six highly contrasting sites, ranging from a temperate mixed shelf station to a permanently stratified tropical deep-ocean station. The physical characteristics are simulated by direct coupling to a 1D vertically resolved turbulence model, parameterised for each site. A mathematical description of the pelagic ecosystem model is presented. Additions to ERSEM II's well resolved community and decoupling of gross production and ambient nutrient concentration include variable carbon to chlorophyll ratios, coupling of bacterial production to nutrient availability, improved resolution of the organic particulate and dissolved fractions and developments to the mesozooplankton description. Comparison of seasonally depth resolved and integrated properties illustrates that the model produces a wide range of community dynamics and structures that can be plausibly related to variations in mixing, temperature, irradiance and nutrient supply. The spatial–temporal variability in key environmental indicators only partially correlates with the spatial–temporal variability in community structure (?0.75) between spatial–temporal variability in community structure (biomass) and function (production). ERSEM-2004 is shown to be a robust model that is capable of representing a range of systems commonly described in the marine system. Consequently, the model is proposed as a potential basis for an ecosystem-based management tool that may, with appropriate physical representation, be applied over large geographic and temporal scales with utility to both heuristic and predictive studies of the marine lower trophic levels.

J.C. Blackford; J.I. Allen; F.J. Gilbert

2004-01-01T23:59:59.000Z

217

Toward a mechanistic modeling of nitrogen limitation on vegetation dynamics  

SciTech Connect

Nitrogen is a dominant regulator of vegetation dynamics, net primary production, and terrestrial carbon cycles; however, most ecosystem models use a rather simplistic relationship between leaf nitrogen content and photosynthetic capacity. Such an approach does not consider how patterns of nitrogen allocation may change with differences in light intensity, growing-season temperature and CO{sub 2} concentration. To account for this known variability in nitrogen-photosynthesis relationships, we develop a mechanistic nitrogen allocation model based on a trade-off of nitrogen allocated between growth and storage, and an optimization of nitrogen allocated among light capture, electron transport, carboxylation, and respiration. The developed model is able to predict the acclimation of photosynthetic capacity to changes in CO{sub 2} concentration, temperature, and radiation when evaluated against published data of V{sub c,max} (maximum carboxylation rate) and J{sub max} (maximum electron transport rate). A sensitivity analysis of the model for herbaceous plants, deciduous and evergreen trees implies that elevated CO{sub 2} concentrations lead to lower allocation of nitrogen to carboxylation but higher allocation to storage. Higher growing-season temperatures cause lower allocation of nitrogen to carboxylation, due to higher nitrogen requirements for light capture pigments and for storage. Lower levels of radiation have a much stronger effect on allocation of nitrogen to carboxylation for herbaceous plants than for trees, resulting from higher nitrogen requirements for light capture for herbaceous plants. As far as we know, this is the first model of complete nitrogen allocation that simultaneously considers nitrogen allocation to light capture, electron transport, carboxylation, respiration and storage, and the responses of each to altered environmental conditions. We expect this model could potentially improve our confidence in simulations of carbon-nitrogen interactions and the vegetation feedbacks to climate in Earth system models.

Xu, Chonggang [Los Alamos National Laboratory (LANL); Fisher, Rosie [National Center for Atmospheric Research (NCAR); Wullschleger, Stan D [ORNL; Wilson, Cathy [Los Alamos National Laboratory (LANL); Cai, Michael [Los Alamos National Laboratory (LANL); McDowell, Nathan [Los Alamos National Laboratory (LANL)

2012-01-01T23:59:59.000Z

218

Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,*  

E-Print Network (OSTI)

1 Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,* , Kisup Leeb building, but cannot provide detailed flow information in a room. The zonal model can be useful when a user ventilation systems for buildings requires a suitable model to assess system performance. The performance can

Chen, Qingyan "Yan"

219

Object-oriented modelling and simulation for the ALFRED dynamics  

Science Journals Connector (OSTI)

Abstract In this paper, a control-oriented modelling and simulation tool for the study of the Advanced Lead-cooled Fast Reactor European Demonstrator (ALFRED) plant dynamics is presented. It has been developed in order to perform design-basis transient analyses aimed at providing essential feedbacks for the system design finalization. The simulator has been meant to be modular, open and efficient. In this perspective, an object-oriented modelling approach has been adopted, by employing the reliable, tested and well-documented Modelica language. Simulation of core behaviour is based on point kinetics for neutronics and one-dimensional heat transfer models for thermal-hydraulics, coherently with ALFRED specifications. An effort has been spent to model the bayonet-tube Steam Generator (SG) foreseen to be installed within the reactor vessel. The primary loop model has been built by connecting the above-mentioned components (taking into account suitable time delays) and by incorporating the cold pool, which has revealed to be fundamental for an accurate definition of the time constants characteristic of the system because of its large thermal inertia. The description of the overall plant has been finalized by connecting standard turbine, condenser and other components of the balance of plant. Afterwards, the reactor responses to three typical transient initiators have been simulated (i.e., reduction of feedwater mass flow rate, variation of the turbine admission valve coefficient and transient of overpower). Simulation outcomes confirm the strong coupling between core and SG, besides showing the characteristic time constants of the various component responses. Results of the present study constitute a starting point in the definition of plant control strategies, laying the basis for investigation and development of a model-based control-system design.

Roberto Ponciroli; Andrea Bigoni; Antonio Cammi; Stefano Lorenzi; Lelio Luzzi

2014-01-01T23:59:59.000Z

220

A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller  

E-Print Network (OSTI)

A Numerical Model for the Dynamic Simulation of a Recirculation Single- Effect Absorption Chiller A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller. Keywords: absorption; chiller; modelling; transient; water-lithium bromide; falling film hal-00713904

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "dynamics models assessing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


221

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances  

E-Print Network (OSTI)

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances C. Canudas we derive a new dynamic friction force model for the longitudinal road/tire interaction for wheeled-point friction problems, called the LuGre model [1]. By assuming a con- tact patch between the tire

Tsiotras, Panagiotis

222

Lateral Dynamics Reconstruction for Sharp'71 Motorcycle Model with P2I Observer  

E-Print Network (OSTI)

Lateral Dynamics Reconstruction for Sharp'71 Motorcycle Model with P2I Observer Chabane Chenane (motorcycle, scooter, etc.). For that purpose, the well-known motorcycle model developed by Sharp in 1971 is used. This model characterizes the lateral dynamics of a motorcycle [16]. The roll angle

Paris-Sud XI, Université de

223

O-regime dynamics and modeling in Tore Supra  

SciTech Connect

The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Equipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r) and the electron temperature T{sub e}(r) where the equation coefficients are functions of j and T{sub e} themselves. Both the integrated modeling code CRONOS[V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Segui, J.-L. [CEA-IRFM, 13108 St. Paul-les-Durance (France)

2009-06-15T23:59:59.000Z

224

THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL  

SciTech Connect

The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 {+-} 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory analysis of the saturated zone water chemistry. The results of the field investigations and laboratory analyses of rock and water samples collected at Nopal I are used to calibrate the Pena Blanca Natural Analogue Model.

G.J. Saulnier Jr; W. Statham

2006-03-10T23:59:59.000Z

225

Modeling Biodiversity Dynamics in Countryside and Native Habitats Henrique M Pereira and Luis Borda-de-Agua, Faculdade de Cie^ncias da Universidade de Lisboa, Lisboa, Portugal  

E-Print Network (OSTI)

Modeling Biodiversity Dynamics in Countryside and Native Habitats Henrique M Pereira and Lui; Pereira et al., 2010). It is therefore es- sential to assess how different patterns of land-use affect at the impacts of climate change (Thuiller et al., 2008; Pereira et al., 2010). However, many of the original

Pereira, Henrique Miguel

226

IN SEARCH OF A PROBABILISTIC MODEL OF PETROLEUM RESOURCE ASSESSMENT  

Science Journals Connector (OSTI)

Publisher Summary This chapter discusses a probabilistic model of petroleum resource assessment. At present, petroleum provides the major driving energy for national economies. The foreseen worldwide depletion of petroleum resources in a few decades, at a time of transition to new energy technologies, imposes hardships on many nations but enhances opportunities for those having a petroleum potential. The petroleum prospective areas of the world consist of sedimentary basins and geosynclines not too intensely deformed tectonically, including the continental shelves down to 200 m depth, with a total area under national jurisdictions of about 26.1 million sq mi. Certain oceanic areas beyond the continental shelves—continental rise and continental slope—have petroleum prospects, but their eventual development may be some 10 to 20 years away. The traditional geologic environment for petroleum has been the geosynclinal belt. The larger the tract of undrilled prospective area, the greater is the chances that thick sedimentary pods may occur here and there. Even when a few scattered pieces of evidence may indicate a thin sedimentary cover, prospects for generation and primary migration of petroleum may be enhanced by the large size of a prospective area. The examination of the distribution of petroleum occurrences throughout the world in basins with a significant amount of exploratory drilling indicates that roughly one-half of the prospective basins and geosynclines do not yield any or much petroleum.

B.F. Grossling

1979-01-01T23:59:59.000Z

227

The Dynamics of Deterministic Chaos in Numerical Weather Prediction Models  

E-Print Network (OSTI)

Atmospheric weather systems are coherent structures consisting of discrete cloud cells forming patterns of rows/streets, mesoscale clusters and spiral bands which maintain their identity for the duration of their appreciable life times in the turbulent shear flow of the planetary Atmospheric Boundary Layer. The existence of coherent structures (seemingly systematic motion) in turbulent flows has been well established during the last 20 years of research in turbulence. Numerical weather prediction models based on the inherently non-linear Navier-Stokes equations do not give realistic forecasts because of the following inherent limitations: (1) the non-linear governing equations for atmospheric flows do not have exact analytic solutions and being sensitive to initial conditions give chaotic solutions characteristic of deterministic chaos (2) the governing equations do not incorporate the dynamical interactions and co-existence of the complete spectrum of turbulent fluctuations which form an integral part of the large coherent weather systems (3) limitations of available computer capacity necessitates severe truncation of the governing equations, thereby generating errors of approximations (4) the computer precision related roundoff errors magnify the earlier mentioned uncertainties exponentially with time and the model predictions become unrealistic. The accurate modelling of weather phenomena therefore requires alternative concepts and computational techniques. In this paper a universal theory of deterministic chaos applicable to the formation of coherent weather structures in the ABL is presented.

A. Mary Selvam

2003-10-07T23:59:59.000Z

228

Emerging disease dynamics in a model coupling within-host and ...  

E-Print Network (OSTI)

Aug 2, 2014 ... Immunological models consider the within-host dynamics independent of the interactions between hosts (e.g., De Leenheer and Smith, 2003;.

Xiuli Cen

2014-08-27T23:59:59.000Z

229

Estimation of Parameterized Spatio-Temporal Dynamic Models Ke Xu and Christopher K. Wikle  

E-Print Network (OSTI)

Estimation of Parameterized Spatio-Temporal Dynamic Models Ke Xu and Christopher K. Wikle: Christopher K. Wikle, Department of Statistics, University of Missouri, 146 Math Science Building, Columbia

230

Dynamic Modeling of Cell Migration and Spreading Behaviors on Fibronectin Coated Planar Substrates and Micropatterned Geometries  

E-Print Network (OSTI)

An integrative cell migration model incorporating focal adhesion (FA) dynamics, cytoskeleton and nucleus remodeling, actin motor activity, and lamellipodia protrusion is developed for predicting cell spreading and migration ...

Kim, Min-Cheol

231

Automated Software Engineering Process Assessment: Supporting Diverse Models using an Ontology  

E-Print Network (OSTI)

, ISO 9001). It also provides an in-the-loop automated process assessment capability that can help, ISO 9001), and suitable performance and scalability. The approach can reduce the effort required assessment while simultaneously supporting diverse process assessment reference models (CMMI, ISO/IEC 15504

Ulm, Universität

232

Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.  

SciTech Connect

Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

2011-06-01T23:59:59.000Z

233

Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment  

E-Print Network (OSTI)

of organohalogen contaminants (dioxins, PCB, PBDE andInvestigation into levels of dioxins, furans, PCBs and PBDEsfor risk assessment of dioxin-contaminated sites. Ambio 36:

Cowan-Ellsberry, Christina E.

2010-01-01T23:59:59.000Z

234

Ensemble operational air quality assessments in Europe Improving modeling platforms with statistical analysis  

E-Print Network (OSTI)

Ensemble operational air quality assessments in Europe ­ Improving modeling platforms. For regional air quality, seven regional modeling teams combine state-of-the-art atmospheric modeling the ensemble or a unique model. Keywords: Air quality, modeling system, ensemble approach, validation

Paris-Sud XI, Université de

235

Assessment of Modes of Interannual Variability of Southern Hemisphere Atmospheric Circulation in CMIP5 Models  

Science Journals Connector (OSTI)

An assessment is made of the modes of interannual variability in the seasonal mean summer and winter Southern Hemisphere (SH) 500-hPa geopotential height in the twentieth century in models from the Coupled Model Intercomparison Project (CMIP) ...

Simon Grainger; Carsten S. Frederiksen; Xiaogu Zheng

2014-11-01T23:59:59.000Z

236

Skill assessment of three earth system models with common marine biogeochemistry  

Science Journals Connector (OSTI)

We have assessed the ability of a common ocean biogeochemical model, PISCES, to match relevant modern data fields across a range of ocean circulation fields from three distinct Earth system models: IPSL-CM4-LOOP,...

Roland Séférian; Laurent Bopp; Marion Gehlen; James C. Orr…

2013-05-01T23:59:59.000Z

237

Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global climate model  

Science Journals Connector (OSTI)

...Sciences Enhancing the Capability of Computational Earth System Models and Using NASA Data for Operation and Assessment...Science, Decadal and Regional Climate Prediction using Earth System Models program (M.W. and S.J.G.). PNNL is operated...

Yuan Wang; Minghuai Wang; Renyi Zhang; Steven J. Ghan; Yun Lin; Jiaxi Hu; Bowen Pan; Misti Levy; Jonathan H. Jiang; Mario J. Molina

2014-01-01T23:59:59.000Z

238

An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC-  

E-Print Network (OSTI)

An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC- HVDC, especially in case of connection of offshore wind power plants (OWPPs). Modelling challenges are faced

Bak, Claus Leth

239

A phenomenological muscle model to assess history dependent effects in human movement  

E-Print Network (OSTI)

A phenomenological muscle model to assess history dependent effects in human movement C.P. Mc of the history dependent effects. The phenomenological model of stretch-induced force enhancement was dependent

Ben-Yakar, Adela

240

Assessing the Potential of Using Traffic Simulation Model Results for Evaluating Automatic Incident Detection Algorithms  

E-Print Network (OSTI)

Assessing the Potential of Using Traffic Simulation Model Results for Evaluating Automatic Incident of such a test-bed would be the ability to incorporate synthetic data produced by a simulation model since

Hellinga, Bruce

Note: This page contains sample records for the topic "dynamics models assessing" 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

Simulation of systems with dynamically varying model structure  

Science Journals Connector (OSTI)

Hybrid systems are dynamical systems composed of components with discrete and continuous behavior. Some systems change their structure during simulation, or their components behavior is essentially changing. This ''structural dynamics'' can be described ... Keywords: Discrete-continuous simulation, Hybrid systems, Modelica, Structural dynamics, VHDL-AMS

Peter Schwarz

2008-12-01T23:59:59.000Z

242

Reduced-Reference Image Quality Assessment Using A Wavelet-Domain Natural Image Statistic Model  

E-Print Network (OSTI)

Reduced-Reference Image Quality Assessment Using A Wavelet-Domain Natural Image Statistic Model information about the reference images. In this paper, we propose an RR image quality assessment method based on a natural image statistic model in the wavelet transform domain. We use the Kullback-Leibler distance

Wang, Zhou

243

Impact Assessment of Abiotic Resources in LCA: Quantitative Comparison of Selected Characterization Models  

Science Journals Connector (OSTI)

Impact Assessment of Abiotic Resources in LCA: Quantitative Comparison of Selected Characterization Models ... Resources have received significant attention in recent years resulting in development of a wide range of resource depletion indicators within life cycle assessment (LCA). ... Finally, we classify the existing methods into three groups, according to method focus and modeling approach, to aid method selection within LCA. ...

Jakob T. Rørbech; Carl Vadenbo; Stefanie Hellweg; Thomas F. Astrup

2014-09-10T23:59:59.000Z

244

Assessing nitrogen losses after sewage sludge spreading: A method based on simulation models and spreader  

E-Print Network (OSTI)

1 Assessing nitrogen losses after sewage sludge spreading: A method based on simulation models performances. We define 45 sewage sludge spreading scenarios covering a wide range of situations in France. Several models are used to (i) assess nitrogen losses due to sewage sludge spreading and (ii) calculate

Paris-Sud XI, Université de

245

Pion photoproduction in a dynamical coupled-channels model  

E-Print Network (OSTI)

The charged and neutral pion photoproduction reactions are investigated in a dynamical coupled-channels approach based on the formulation of Haberzettl, Huang, and Nakayama [Phys. Rev. C 83, 065502 (2011)]. The hadronic final-state interaction is provided by the Juelich pi-N model, which includes the channels pi-N and eta-N comprising stable hadrons as well as the effective pi-pi-N channels pi-Delta, sigma-N, and rho-N. This hadronic model has been quite successful in describing pi-N to pi-N scattering for center-of-mass energies up to 1.9 GeV. By construction, the full pion photoproduction current satisfies the generalized Ward-Takahashi identity and thus is gauge invariant as a matter of course. The calculated differential cross sections and photon spin asymmetries up to 1.65 GeV center-of-mass energy for the reactions gamma p to pi+ n, gamma p to pi0 p, gamma n to pi- p and gamma n to pi0 n are in good agreement with the experimental data.

Huang, F; Haberzettl, H; Haidenbauer, J; Hanhart, C; Krewald, S; ner, U -G Meiß; Nakayama, K

2011-01-01T23:59:59.000Z

246

Pion photoproduction in a dynamical coupled-channels model  

E-Print Network (OSTI)

The charged and neutral pion photoproduction reactions are investigated in a dynamical coupled-channels approach based on the formulation of Haberzettl, Huang, and Nakayama [Phys. Rev. C 83, 065502 (2011)]. The hadronic final-state interaction is provided by the Juelich pi-N model, which includes the channels pi-N and eta-N comprising stable hadrons as well as the effective pi-pi-N channels pi-Delta, sigma-N, and rho-N. This hadronic model has been quite successful in describing pi-N to pi-N scattering for center-of-mass energies up to 1.9 GeV. By construction, the full pion photoproduction current satisfies the generalized Ward-Takahashi identity and thus is gauge invariant as a matter of course. The calculated differential cross sections and photon spin asymmetries up to 1.65 GeV center-of-mass energy for the reactions gamma p to pi+ n, gamma p to pi0 p, gamma n to pi- p and gamma n to pi0 n are in good agreement with the experimental data.

F. Huang; M. Döring; H. Haberzettl; J. Haidenbauer; C. Hanhart; S. Krewald; U. -G. Meiß ner; K. Nakayama

2011-10-17T23:59:59.000Z

247

Ultrafast Structural Dynamics in Combustion Relevant Model Systems  

SciTech Connect

The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the molecule’s structure. Building on this insight, we have developed a structurally sensitive spectroscopy: the molecule is first elevated to the Rydberg state, and the binding energy is then measured using photoelectron spectroscopy. The molecule’s structure is read out as the binding energy spectrum. Since the photoionization can be done with ultrafast laser pulses, the technique is inherently capable of a time resolution in the femtosecond regime. For the purpose of identifying the structures of molecules during chemical reactions, and for the analysis of molecular species in the hot environments of combustion processes, there are several features that make the Rydberg ionization spectroscopy uniquely useful. First, the Rydberg electron’s orbit is quite large and covers the entire molecule for most molecular structures of combustion interest. Secondly, the ionization does not change vibrational quantum numbers, so that even complicated and large molecules can be observed with fairly well resolved spectra. In fact, the spectroscopy is blind to vibrational excitation of the molecule. This has the interesting consequence for the study of chemical dynamics, where the molecules are invariably very energetic, that the molecular structures are observed unobstructed by the vibrational congestion that dominates other spectroscopies. This implies also that, as a tool to probe the time-dependent structural dynamics of chemically interesting molecules, Rydberg spectroscopy may well be better suited than electron or x-ray diffraction. With recent progress in calculating Rydberg binding energy spectra, we are approaching the point where the method can be evolved into a structure determination method. To implement the Rydberg ionization spectroscopy we use a molecular beam based, time-resolved pump-probe multi-photon ionization/photoelectron scheme in which a first laser pulse excites the molecule to a Rydberg state, and a probe pulse ionizes the molecule. A time-of-flight detector measures the kinetic energy spectrum of the photoelectrons. The photoelectron spectrum directly provides the binding energy of the electron, and thereby reveals the molecule’s time-dependent structural fingerprint. Only the duration of the laser pulses limits the time resolution. With a new laser system, we have now reached time resolutions better than 100 fs, although very deep UV wavelengths (down to 190 nm) have slightly longer instrument functions. The structural dynamics of molecules in Rydberg-excited states is obtained by delaying the probe ionization photon from the pump photon; the structural dynamics of molecules in their ground state or e

Weber, Peter M. [Brown University

2014-03-31T23:59:59.000Z

248

Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment  

E-Print Network (OSTI)

LS I +61 303 is a puzzling Be/X-ray binary with variable gamma-ray emission at up TeV energies. The nature of the compact object and the origin of the high-energy emission are unclear. One family of models invokes particle acceleration in shocks from the collision between the B-star wind and a relativistic pulsar wind, while another centers on a relativistic jet powered by accretion. Recent high-resolution radio observations showing a putative "cometary tail" pointing away from the Be star near periastron have been cited as support for the pulsar-wind model. We wish here to carry out a quantitative assessment of these competing models for this extraordinary source. We apply a 3D SPH code for dynamical simulations of both the pulsar-wind-interaction and accretion-jet models. The former yields a description of the shape of the wind-wind interaction surface. The latter provides an estimation of the accretion rate. The results allow critical evaluation of how the two distinct models confront the data in various wavebands under a range of conditions. When one accounts for the 3D dynamical wind interaction under realistic constraints for the relative strength of the B-star and pulsar winds, the resulting form of the interaction front does not match the putative "cometary tail" claimed from radio observations. On the other hand, dynamical simulations of the accretion-jet model indicate that the orbital phase variation of accretion power includes a secondary broad peak well away from periastron, thus providing a plausible way to explain the observed TeV gamma ray emission toward apastron. We conclude that the colliding-wind model is not clearly established for LS I +61 303, while the accretion-jet model can reproduce many key characteristics of the observed TeV gamma-ray emission.

G. E. Romero; A. T. Okazaki; M. Orellana; S. P. Owocki

2007-06-09T23:59:59.000Z

249

Networking technology adoption : system dynamics modeling of fiber-to-the-home  

E-Print Network (OSTI)

A system dynamics model is developed and run to study the adoption of fiber-to-the-home as a residential broadband technology. Communities that currently do not have broadband in the United States are modeled. This case ...

Kelic, Andjelka, 1972-

2005-01-01T23:59:59.000Z

250

A comparison of Bayesian versus deterministic formulation for dynamic data integration into reservoir models  

E-Print Network (OSTI)

Into Reservoir Models. (Decmnber 200 I) Danny LL Rojas Paico, B. S. , Universidad Nacional de Ingenieria, Peru Chair of Advisory Committee: Dr. Akhil Datta-Gupta The integration of dynamic data into reservoir models is known as automatic history matching...

Rojas Paico, Danny H.

2001-01-01T23:59:59.000Z

251

Evolutionary Processes in Economics: Multi-agent Model of Macrogenerations Dynamics  

E-Print Network (OSTI)

Evolutionary Processes in Economics: Multi-agent Model of Macrogenerations Dynamics Kateryna macroeconomic growth as an evolutionary process. Keywords. Economic growth, evolutionary theory, multi]. Our study models the economic growth as an evolutionary process, where the term `macrogeneration

López-Sánchez, Maite

252

A Blended Soundproof-to-Compressible Numerical Model for Small- to Mesoscale Atmospheric Dynamics  

Science Journals Connector (OSTI)

A blended model for atmospheric flow simulations is introduced that enables seamless transition from fully compressible to pseudo-incompressible dynamics. The model equations are written in nonperturbation form and integrated using a well-balanced ...

Tommaso Benacchio; Warren P. O’Neill; Rupert Klein

2014-12-01T23:59:59.000Z

253

STOCHASTIC COMPUTATIONAL DYNAMICAL MODEL OF UNCERTAIN STRUCTURE COUPLED WITH AN INSULATION LAYER  

E-Print Network (OSTI)

STOCHASTIC COMPUTATIONAL DYNAMICAL MODEL OF UNCERTAIN STRUCTURE COUPLED WITH AN INSULATION LAYER the effect of insulation layers in complex dynamical systems for low- and medium-frequency ranges such as car booming noise analysis, one introduces a sim- plified stochastic model of insulation layers based

Boyer, Edmond

254

A stochastic agent-based model of pathogen propagation in dynamic multi-relational social networks  

Science Journals Connector (OSTI)

We describe a general framework for modeling and stochastic simulation of epidemics in realistic dynamic social networks, which incorporates heterogeneity in the types of individuals, types of interconnecting risk-bearing relationships, and types of ... Keywords: Agent-based systems, Social Factors for HIV Risk, modeling and simulation environments, network-based simulation, risk network, system dynamics

Bilal Khan, Kirk Dombrowski, Mohamed Saad

2014-04-01T23:59:59.000Z

255

A DYNAMICAL MODEL OF TERRORISM FIRDAUS UDWADIA, GEORGE LEITMANN, AND LUCA LAMBERTINI  

E-Print Network (OSTI)

A DYNAMICAL MODEL OF TERRORISM FIRDAUS UDWADIA, GEORGE LEITMANN, AND LUCA LAMBERTINI Received 25 April 2006; Accepted 10 May 2006 This paper develops a dynamical model of terrorism. We consider the susceptibles to become pacifists. The paper proposes a new paradigm for studying terrorism, and looks

Udwadia, Firdaus E.

256

The living cell as a multi-agent organisation: a compositional organisation model of intracellular dynamics  

Science Journals Connector (OSTI)

Within the areas of Computational Organisation Theory and Artificial Intelligence, techniques have been developed to simulate and analyse dynamics within organisations in society. Usually these modelling techniques are applied to factories and to the ... Keywords: dynamics, intracellular, modular control analysis, organisational modeling, regulation and control

C. M. Jonker; J. L. Snoep; J. Treur; H. V. Westerhoff; W. C. A. Wijngaards

2010-01-01T23:59:59.000Z

257

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results  

E-Print Network (OSTI)

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results C. Canudas dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles is val- idated via experiments with an actual passenger vehicle. Contrary to common static friction/slip maps

Tsiotras, Panagiotis

258

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle  

E-Print Network (OSTI)

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle Haider N. Arafat-- A dynamic model is developed for a small, high- speed autonomous underwater vehicle. The vehicle has manner: 1) Wind angle and angle : From u = V cos , v = V sin sin , and w = V sin cos , we have tan

Virginia Tech

259

Filtering Noisy ECG Signals Using the Extended Kalman Filter Based on a Modified Dynamic ECG Model  

E-Print Network (OSTI)

Filtering Noisy ECG Signals Using the Extended Kalman Filter Based on a Modified Dynamic ECG Model for the filtering of noisy ECG signals. The method is based on a modified nonlinear dynamic model, previously introduced for the generation of synthetic ECG signals. An automatic parameter selection method has also been

Paris-Sud XI, Université de

260

ECG Denoising Using a Dynamical Model and a Marginalized Particle Filter  

E-Print Network (OSTI)

ECG Denoising Using a Dynamical Model and a Marginalized Particle Filter Chao Lin1,3, M of robust ECG denoising tech- niques is important for automatic diagnoses of cardiac diseases. Based on a previously suggested nonlinear dynamic model for the generation of realistic synthetic ECG, we introduce

Tourneret, Jean-Yves

Note: This page contains sample records for the topic "dynamics models assessing" 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

Model for a web based medical technology assessment system  

E-Print Network (OSTI)

will form the backbone of this system. Various queries can be run to produce the desired results. This system will provide a means for assessing the currently available medical technology. Based on the information present in the system clinical engineers...

Prabhu, Gopal

1999-01-01T23:59:59.000Z

262

System dynamics-based modelling and analysis of greening the construction industry supply chain  

Science Journals Connector (OSTI)

Increasing concern on global warming and corporate social responsibility have made environmental issues an area of importance to address for governments and businesses across the world. Among the Middle East countries, the United Arab Emirates (UAE) tops the list in terms of per capita energy spending and per capita carbon footprints. The construction industry is the major contributor to environmental pollution due to its size and nature of activity. The rapid growth of construction sector has a significant environmental impact with increase in carbon footprints. This paper analyses the environmental implications of the rapidly growing construction industry in UAE using system dynamics approach. Quantitative modelling of the construction industry supply chain helps to measure the dynamic interaction between its various factors under multiple realistic scenarios. The potential carbon savings and the impact of each factor are calculated using scenario development analysis. The paper has addressed in detail the various drivers and inhibitors of carbon emission in the construction industry supply chain and ways to evaluate the carbon savings. The paper provides an analytical decision framework to assess emissions of all stages applicable to the construction industry supply chain.

Balan Sundarakani; Arijit Sikdar; Sreejith Balasubramanian

2014-01-01T23:59:59.000Z

263

[10-386] Assessing and Improving the Scale Dependence of Ecosystem Processes in Earth System Models  

E-Print Network (OSTI)

. Goodale Cornell U. *Overall Project Lead *Lead Institution Intellectual Merit: Earth system models include policies. Our research assesses and improves Earth system model simulations of the carbon cycle, ecosystem of the Community Climate System Model/Community Earth System Model, which includes statistical meteorological

264

Coupled thermodynamic-dynamic semi-analytical model of Free Piston Stirling engines  

E-Print Network (OSTI)

The study of free piston Stirling engine (FPSE) requires both accurate thermodynamic and dynamic modelling to predict its performances. The steady state behaviour of the engine partly relies on non linear dissipative phenomena such as pressure drop loss within heat exchangers which is dependant on the temperature within the associated components. An analytical thermodynamic model which encompasses the effectiveness and the flaws of the heat exchangers and the regenerator has been previously developed and validated. A semi-analytical dynamic model of FPSE is developed and presented in this paper. The thermodynamic model is used to define the thermal variables that are used in the dynamic model which evaluates the kinematic results. Thus, a coupled iterative strategy has been used to perform a global simulation. The global modelling approach has been validated using the experimental data available from the NASA RE-1000 Stirling engine prototype. The resulting coupled thermodynamic-dynamic model using a standard...

Formosa, Fabien

2013-01-01T23:59:59.000Z

265

Dynamic models towards operator and engineer training: Virtual environment  

Science Journals Connector (OSTI)

The simulation of chemical processes is an important tool for solving problems in Computer Aided Process Engineering (CAPE) and the use of commercial simulators is essential for this task. In this work, the intention is to create a virtual environment for industrial process and data representations for operator and engineer training. The applications focus on the separation process dynamic and control. The first case is an azeotropic distillation process. It was used an industrial plant data to illustrate the importance of reliable thermodynamic data to the process simulation. The system studied is the ethanol/water separation using cyclohexane as mass separating agent. As the second case, it was used a refinery data to simulate the debutanizer column of a fluid catalytic cracking unit in order to make this complex problem understandable, well represented and easily reproducible in a simulation framework. In this case, optimization, regulatory control, PID tuning and model predictive control were considered. The energy consumption was minimized using the SQP method. Simulations were performed using HYSYS. Plant process simulator.

Claudia J.G. Vasconcelos; Rubens Maciel Filho; Renato Spandri; Maria R. Wolf-Maciel

2005-01-01T23:59:59.000Z

266

Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT  

Science Journals Connector (OSTI)

Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)?1, cardiac output = 3, 5, 8 L min?1). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This suggests that there is no particular advantage between quantitative estimation methods nor to performing dose reduction via tube current reduction compared to temporal sampling reduction. These data are important for optimizing implementation of cardiac dynamic CT in clinical practice and in prospective CT MBF trials.

Michael Bindschadler; Dimple Modgil; Kelley R Branch; Patrick J La Riviere; Adam M Alessio

2014-01-01T23:59:59.000Z

267

Modeling Thermodynamics and Dynamics of MixtureModeling Thermodynamics and Dynamics of Mixture Adsorption in Porous MaterialsAdsorption in Porous Materials  

E-Print Network (OSTI)

models to describe adsorption dynamics · Apply to case of Enhanced Coalbed Methane Extraction ­ Trillions of cubic meters of methane and carbon dioxide can be extracted and stored in unusable coal seams Models temperature, adsorption increases with pressure. Carbon Dioxide interacts more strongly with coal than methane

Mountziaris, T. J.

268

Dynamic energy budget approaches for modelling organismal ageing  

Science Journals Connector (OSTI)

...12 November 2010 research-article Articles...Developments in dynamic energy budget theory and...metabolism. The Dynamic Energy Budgets (DEB...uptake and use of energy by living organisms...fate. From a more abstract and generic point...efforts, several research groups have used...

2010-01-01T23:59:59.000Z

269

A Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei  

Open Energy Info (EERE)

Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Details Activities (0) Areas (0) Regions (0) Abstract: We present here a consistent model, which explains the mechanisms of unrest phenomena at Campi Flegrei (Italy), both at short-term (years) and at secular scales. The model consists basically of two effects: the first one is related to the elastic response of the shallow crust to increasing pressure within a shallow magma chamber; the second involves the fluid-dynamics of shallow aquifers in response to increasing pressure and/or temperature at depth. The most important roles in the proposed model

270

Fire dynamics during the 20th century simulated by the Community Land Model  

E-Print Network (OSTI)

Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce ...

Kloster, S.; Mahowald, N. M.; Randerson, J. T.; Thornton, P. E.; Hoffman, F. M.; Levis, Samuel; Lawrence, P. J.; Feddema, Johannes J.; Oleson, Keith W.; Lawrence, D. M.

2010-01-01T23:59:59.000Z

271

Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models  

E-Print Network (OSTI)

1 Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models distilled from measure data, rather than models derived from transformer heat for measuring the acceptability of transformer thermal models. For a model to be acceptable, it must have

272

The Niobrara River Basin Study: Using Various Models to Assess  

E-Print Network (OSTI)

Seminar Series Brandi Flyr, Ph.D. Integrated Water Management Division Nebraska Department of Natural;#12;Integrated Water Management Identify Management Setting Assess Water Resources Understand & Predict Set effects of various water management strategies in order to develop water management tools #12;Goals

Farritor, Shane

273

A new analytic-adaptive model for EGS assessment, development...  

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

Categorical Exclusion Determination Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Predicting Stimulation Response...

274

Modeling and Algorithm for DynamicModeling and Algorithm for Dynamic Multi-Objective Max-CSPsMulti-Objective Max-CSPs  

E-Print Network (OSTI)

_n is blow m. ­ e.g. m=5 : No (3,3) / Yes (4,1) #12;Multi-Objective Max-CSP (Properties) For a cost vector RModeling and Algorithm for DynamicModeling and Algorithm for Dynamic Multi-Objective Max-CSPsMulti-Objective Max-CSPs Tenda Okimoto ¹², Tony Rebeiro ³, Maxime Clement and Katsumi Inoue ² ¹ Transdisciplinary

Banbara, Mutsunori

275

Models used to assess the performance of photovoltaic systems.  

SciTech Connect

This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

Stein, Joshua S.; Klise, Geoffrey T.

2009-12-01T23:59:59.000Z

276

COMPUTATIONAL FLUID DYNAMICS MODELING OF SCALED HANFORD DOUBLE SHELL TANK MIXING - CFD MODELING SENSITIVITY STUDY RESULTS  

SciTech Connect

The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.

JACKSON VL

2011-08-31T23:59:59.000Z

277

Predictions from an Ising-like Statistical Mechanical Model on the Dynamic and Thermodynamic Effects of Protein Surface Electrostatics  

Science Journals Connector (OSTI)

Predictions from an Ising-like Statistical Mechanical Model on the Dynamic and Thermodynamic Effects of Protein Surface Electrostatics ...

Athi N. Naganathan

2012-10-05T23:59:59.000Z

278

Assessing the protective effect of mountain forests against rockfall using a 3D simulation model  

E-Print Network (OSTI)

Assessing the protective effect of mountain forests against rockfall using a 3D simulation model and compared the results obtained with the 3D simulation model RockyFor with empirical data on tree impacts; Rockfall; 3D simulation model; Swiss Alps 1. Introduction Many mountain forests effectively protect people

Stoffel, Markus

279

Sub-AQUA: real-value quality assessment of protein structure models  

E-Print Network (OSTI)

Sub-AQUA: real-value quality assessment of protein structure models Yifeng David Yang1, Preston of Natural Science, Chung-Ang University, Seoul, Korea, 3 Department of Computer Science, College of Science developed quality assessment methods, which predict real value of the global and local quality of protein

Kihara, Daisuke

280

U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS, AND NGL  

E-Print Network (OSTI)

AM-i Chapter AM U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS Survey (USGS) periodically conducts assessments of the oil, gas, and natural-gas liquids (NGL) resources by the USGS in1998 for undiscovered oil, gas, and NGL resources that reside in conventional accumulations

Laughlin, Robert B.

Note: This page contains sample records for the topic "dynamics models assessing" 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

Dynamics of the Structural Glass Transition and the p-Spin—Interaction Spin-Glass Model  

Science Journals Connector (OSTI)

The mathematical structure of the dynamical theory for the soft-spin version of the p-spin-interaction (p>2) spin-glass model is related to that for the dynamical theories of the structural glass transition. The phase transitions predicted by both theories are discussed. The spin-glass transition predicted by the dynamical theory is related to a broken-replica-symmetry equilibrium calculation.

T. R. Kirkpatrick and D. Thirumalai

1987-05-18T23:59:59.000Z

282

DYNAMICAL MODEL FOR THE ZODIACAL CLOUD AND SPORADIC METEORS  

SciTech Connect

The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter, thermally destroyed near the Sun, or physically disrupted by collisions. Also, some are swept by the Earth (and other planets), producing meteors. Here we develop a dynamical model for the solar system meteoroids and use it to explain meteor radar observations. We find that the Jupiter Family Comets (JFCs) are the main source of the prominent concentrations of meteors arriving at the Earth from the helion and antihelion directions. To match the radiant and orbit distributions, as measured by the Canadian Meteor Orbit Radar (CMOR) and Advanced Meteor Orbit Radar (AMOR), our model implies that comets, and JFCs in particular, must frequently disintegrate when reaching orbits with low perihelion distance. Also, the collisional lifetimes of millimeter particles may be longer ({approx}> 10{sup 5} yr at 1 AU) than postulated in the standard collisional models ({approx}10{sup 4} yr at 1 AU), perhaps because these chondrule-sized meteoroids are stronger than thought before. Using observations of the Infrared Astronomical Satellite to calibrate the model, we find that the total cross section and mass of small meteoroids in the inner solar system are (1.7-3.5) Multiplication-Sign 10{sup 11} km{sup 2} and {approx}4 Multiplication-Sign 10{sup 19} g, respectively, in a good agreement with previous studies. The mass input required to keep the zodiacal cloud in a steady state is estimated to be {approx}10{sup 4}-10{sup 5} kg s{sup -1}. The input is up to {approx}10 times larger than found previously, mainly because particles released closer to the Sun have shorter collisional lifetimes and need to be supplied at a faster rate. The total mass accreted by the Earth in particles between diameters D = 5 {mu}m and 1 cm is found to be {approx}15,000 tons yr{sup -1} (factor of two uncertainty), which is a large share of the accretion flux measured by the Long Term Duration Facility. The majority of JFC particles plunge into the upper atmosphere at <15 km s{sup -1} speeds, should survive the atmospheric entry, and can produce micrometeorite falls. This could explain the compositional similarity of samples collected in the Antarctic ice and stratosphere, and those brought from comet Wild 2 by the Stardust spacecraft. Meteor radars such as CMOR and AMOR see only a fraction of the accretion flux ({approx}1%-10% and {approx}10%-50%, respectively), because small particles impacting at low speeds produce ionization levels that are below these radars' detection capabilities.

Nesvorny, David; Vokrouhlicky, David; Pokorny, Petr; Bottke, William F. [Department of Space Studies, Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States); Janches, Diego [Space Weather Laboratory, Code 674, GSFC/NASA, Greenbelt, MD 20771 (United States); Jenniskens, Peter [Carl Sagan Center, SETI Institute, 515 N. Whisman Road, Mountain View, CA 94043 (United States)

2011-12-20T23:59:59.000Z

283

On the use of fuzzy inference techniques in assessment models: part II: industrial applications  

Science Journals Connector (OSTI)

In this paper, we study the applicability of the monotone output property and the output resolution property in fuzzy assessment models to two industrial Failure Mode and Effect Analysis (FMEA) problems. First, t...

Kai Meng Tay; Chee Peng Lim

2008-09-01T23:59:59.000Z

284

A Statistical Model to Assess Indirect CO2 Emissions of the UAE Residential Sector  

E-Print Network (OSTI)

. Determination of household energy using ?fingerprints? from energy billing data. Energy Research 10(4), pp: 393?405. [5] Snakin JPA, 2000. An engineering model for heating energy and emission assessment The case of North Karelia, Finland. Applied Energy...

Radhi, H.; Fikry, F.

2010-01-01T23:59:59.000Z

285

Integrated modelling and assessment of regional groundwater resources in Germany and Benin, West Africa  

E-Print Network (OSTI)

1 Integrated modelling and assessment of regional groundwater resources in Germany and Benin, West.J.S. SONNEVELD [1] Institute of Hydraulic Engineering, Universitaet Stuttgart, Germany (Roland Conservation University of Bonn, Germany [3] Institute of Landscape Planning and Ecology, University

Cirpka, Olaf Arie

286

A Model for Fuzzy Logic Assessment of Real Estate Investment Risks  

Science Journals Connector (OSTI)

Assessing the real estate investment risks is a major issue for the responsible management and the sustainable regional development. The paper proposes a fuzzy logic model for complex estimation of the real estate

Plamena Zlateva; Dimiter Velev…

2011-01-01T23:59:59.000Z

287

Using Noncompensatory Models in Cognitive Diagnostic Mathematics Assessments: An Evaluation Based on Empirical Data  

E-Print Network (OSTI)

The present study evaluates the performance of four noncompensatory cognitive diagnostic models -- AHM, DINA, Fusion, and Bayesian Networks -- using both formative and large-scale mathematics assessments (Fraction dataset, ...

Zhao, Fei

2013-08-31T23:59:59.000Z

288

METHODOLOGY ARTICLE Open Access Quality assessment of protein model-structures  

E-Print Network (OSTI)

similar to proteins functionally similar to the prediction target. Whereas DALI is used to measure structure similarity, protein functional similarity is quantified using standardized and hierarchical model quality assessment method, the other is its modification, which provides a relative measure

Nebel, Jean-Christophe

289

Models Used to Assess the Performance of Photovoltaic Systems  

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

This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization.

290

Assessment  

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

Assessment of the Surveillance Program of the High-Level Waste Storage Tanks at Hanford :.I LALI iE REJ 163 ROOM 1t 4 F77L. -77 .:earmn OfEeg Asitn Sertr fo niomn 4 z. r...

291

Towards Modeling Dynamic Behavior with Integrated Qualitative Spatial Relations  

Science Journals Connector (OSTI)

Situation awareness and geographic information systems in dynamic spatial systems such as road traffic management (RTM) aim to detect and predict critical situations on the basis of relations between entities....

Stefan Mitsch; Werner Retschitzegger…

2011-01-01T23:59:59.000Z

292

Dynamic reduced order modeling of entrained flow gasifiers  

E-Print Network (OSTI)

Gasification-based energy systems coupled with carbon dioxide capture and storage technologies have the potential to reduce greenhouse gas emissions from continued use of abundant and secure fossil fuels. Dynamic reduced ...

Monaghan, Rory F. D. (Rory Francis Desmond)

2010-01-01T23:59:59.000Z

293

Dynamical Modeling of Economy in Global Nuclear Energy Market  

Science Journals Connector (OSTI)

Non-linear dynamical analysis for the global nuclear energy market is investigated. Currently, the market means a different characteristics comparing to the ... between two countries, which depends on the energy ...

Taeho Woo

2012-01-01T23:59:59.000Z

294

Structural models of bioactive glasses from molecular dynamics simulations  

Science Journals Connector (OSTI)

...to adsorb and dissociate a water molecule (Tilocca Cormack 2008...the available computational power steadily grows, it will become...surface of bioactive glasses: water adsorption and reactivity...soda-lime silicate glasses by Car-Parrinello molecular dynamics...

2009-01-01T23:59:59.000Z

295

Predicting and understanding forest dynamics using a simple tractable model  

E-Print Network (OSTI)

the dynamics of size distributions and wood volume and, hence, carbon in even-aged plantation monocul- tures patterns in the biomass, structure, and species composition of forests (4). This problem limits our ability

Lichstein, Jeremy W.

296

A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano,  

Open Energy Info (EERE)

For The Dynamics Of Pyroclastic Flows At Galeras Volcano, For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a two-dimensional model for dilute pyroclastic flow dynamics that uses the compressible Navier-Stokes equation coupled with the Diffusion-Convection equation to take into account sedimentation. The model is applied to one of the slopes of Galeras Volcano to show: (1) the temperature evolution with the time; (2) dynamic pressure change; and (3) particle concentration along the computer domain from the eruption to the impact with a topographic barrier located more than 16 km

297

An investigation into the use of biokinetic models when assessing intakes of plutonium  

E-Print Network (OSTI)

AN INVESTIGATION INTO THE USE OF BIOKINETIC MODELS WHEN ASSESSING INTAKES OF PLUTONIUM A Thesis by BRIAN ANDREW HRYCUSHKO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 2008 Major Subject: Health Physics AN INVESTIGATION INTO THE USE OF BIOKINETIC MODELS WHEN ASSESSING INTAKES OF PLUTONIUM A Thesis by BRIAN ANDREW HRYCUSHKO Submitted...

Hrycushko, Brian Andrew

2008-10-10T23:59:59.000Z

298

Assessment of impact of dynamic route guidance through variable message signs  

E-Print Network (OSTI)

Integration of Intelligent Transportation Systems (ITS) technologies with traffic surveillance has the potential of reducing the delays and costs incurred due to non-recurrent congestion through the dissemination of dynamic ...

Rathi, Vaibhav

2007-01-01T23:59:59.000Z

299

Assessing dynamics, spatial scale, and uncertainty in task-related brain network analyses  

E-Print Network (OSTI)

The brain is a complex network of interconnected elements, whose interactions evolve dynamically in time to cooperatively perform specific functions. A common technique to probe these interactions involves multi-sensor ...

Stephen, Emily P.; Lepage, Kyle Q.; Eden, Uri T.; Brunner, Peter; Schalk, Gerwin; Brumberg, Jonathan S.; Guenther, Frank H.; Kramer, Mark A.

2014-03-19T23:59:59.000Z

300

Statewide and Electricity-Sector Models for Economic Assessments of  

E-Print Network (OSTI)

economic models applied to such diverse fields as climate change policy, alternative- fueled vehicles, fuel Economic Research Organization and Affiliate Faculty with the Public Policy Center UHM. Paul Bernstein, Ph....................................................................................................................... 6 2. The Hawaii Computable General Equilibrium Model (H-CGE)............................ 8 2.a. Data

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to obtain the most current and comprehensive results.


301

Modeling DNA in Confinement: A Comparison between the Brownian Dynamics and Lattice Boltzmann Method  

E-Print Network (OSTI)

Modeling DNA in Confinement: A Comparison between the Brownian Dynamics and Lattice Boltzmann from both the lattice Boltzmann method (LBM) and the Brownian dynamics simulations with fluctuating. We find that the lattice Boltzmann method is well-suited for long polymer chains as well

302

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model  

E-Print Network (OSTI)

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model 1 dynamics, lIre performed at four diameters behind a 95 kW wind turbine. The wake 111eaeasurement technique allows esti111ation of qUClsiinstantancou~ two dimensional wind fields in an area

303

An Energy-Aware Simulation Model and Transaction Protocol for Dynamic Workload Distribution in Mobile Ad Hoc Networks1  

E-Print Network (OSTI)

An Energy-Aware Simulation Model and Transaction Protocol for Dynamic Workload Distribution California {tari, prong, pedram}@usc.edu Abstract This paper introduces a network simulation model

Pedram, Massoud

304

Utility of Social Modeling in Assessment of a State’s Propensity for Nuclear Proliferation  

SciTech Connect

This report is the third and final report out of a set of three reports documenting research for the U.S. Department of Energy (DOE) National Security Administration (NASA) Office of Nonproliferation Research and Development NA-22 Simulations, Algorithms, and Modeling program that investigates how social modeling can be used to improve proliferation assessment for informing nuclear security, policy, safeguards, design of nuclear systems and research decisions. Social modeling has not to have been used to any significant extent in a proliferation studies. This report focuses on the utility of social modeling as applied to the assessment of a State's propensity to develop a nuclear weapons program.

Coles, Garill A.; Brothers, Alan J.; Whitney, Paul D.; Dalton, Angela C.; Olson, Jarrod; White, Amanda M.; Cooley, Scott K.; Youchak, Paul M.; Stafford, Samuel V.

2011-06-01T23:59:59.000Z

305

Biological assessment of robust noise models in microarray data analysis  

Science Journals Connector (OSTI)

......Compatibility with our ANOVA model suggests applying a Kruskal-Wallis permutation test (cf. Lee et al., 2005) and...under KW perm. illustrate the agreements of the Kruskal-Wallis permutation test with the robust parametric method......

A. Posekany; K. Felsenstein; P. Sykacek

2011-03-15T23:59:59.000Z

306

A new analytic-adaptive model for EGS assessment, development...  

Open Energy Info (EERE)

is that there are new solutions to heat extraction from an as-created, enhanced fracture system of EGS. The project will develop a new THMC simulation model with new...

307

GIS and plume dispersion modeling for population exposure assessment  

E-Print Network (OSTI)

. Traditional methods of dispersion modeling for the permitting of new sources and the monitoring of existing sources have allowed much room for error in terms of the effect of the pollutants on nearby populations (Hardikar, 1995). The capabilities of GIS...

Archer, Jeffrey Keith

2012-06-07T23:59:59.000Z

308

Ensemble regression : using ensemble model output for atmospheric dynamics and prediction  

E-Print Network (OSTI)

Ensemble regression (ER) is a linear inversion technique that uses ensemble statistics from atmospheric model output to make dynamical inferences and forecasts. ER defines a multivariate regression operator using ensemble ...

Gombos, Daniel (Daniel Lawrence)

2009-01-01T23:59:59.000Z

309

Dynamic soil-structure interaction-comparison of FEM model with experimental results  

E-Print Network (OSTI)

to represent twenty different laboratory experiments. The results of these models are compared with results available from extensive experimental dynamic testing on a geotechnical centrifuge. Though the various results from the finite element analysis...

Srinivasan, Palanivel Rajan

2012-06-07T23:59:59.000Z

310

Finite Element Modelling and Molecular Dynamic Simulations of Carbon nanotubes/ Polymer Composites  

E-Print Network (OSTI)

Modeling of single-walled carbon nanotubes, multi-walled nanotubes and nanotube reinforced polymer composites using both the Finite Element method and the Molecular Dynamic simulation technique is presented. Nanotubes subjected to mechanical loading...

Gaddamanugu, Dhatri

2010-07-14T23:59:59.000Z

311

A dynamic model of a self-vibration cycle in a stirling engine with opposed cylinders  

Science Journals Connector (OSTI)

A dynamic model of the self-vibration cycle in an engine with opposed cylinders and two pistons located on a common guide bar is studied. To each cylinder containing a working liquid, a pair of hydraulic accum...

M. Ya. Izrailovich; A. V. Sinev…

2007-06-01T23:59:59.000Z

312

Constraining dynamical dark energy models through the abundance of high-redshift supermassive black holes  

Science Journals Connector (OSTI)

......Constraining dynamical dark energy models through the abundance...its contribution to the energy density would become rapidly...provided by the NASA Joint Dark Energy Mission (JDEM) -Wide-Field Infrared Survey Telescope (WFIRST) space......

A. Lamastra; N. Menci; F. Fiore; C. Di Porto; L. Amendola

2012-03-01T23:59:59.000Z

313

Model predictive controller design for the dynamic positioning system of a semi-submersible platform  

Science Journals Connector (OSTI)

This paper researches how to apply the advanced control technology of model predictive control (MPC) to the design of the dynamic positioning system (DPS) of a semi-submersible platform. First, a linear low-frequ...

Hongli Chen; Lei Wan; Fang Wang…

2012-09-01T23:59:59.000Z

314

A Mechanical Fluid-Dynamical Model For Ground Movements At Campi...  

Open Energy Info (EERE)

Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Mechanical...

315

A Dynamic household Alternative-fuel Vehicle Demand Model Using Stated and Revealed Transaction Information  

E-Print Network (OSTI)

market share for alternative-fuel vehicles drop from thePreferences for Alternative-Fuel Vehicles”, Brownstone DavidA Dynamic Household Alternative-fuel Vehicle Demand Model

Sheng, Hongyan

1999-01-01T23:59:59.000Z

316

Groundwater pollution from agrochemicals — A dynamic model of externalities and policy options  

Science Journals Connector (OSTI)

A dynamic model of groundwater pollution from intensive agrochemical use is developed in this paper to capture the possible externalities and analyze various policy options in protecting groundwater resources. Fo...

Suresh Chandra Babu; B. Thirumalai Nivas; B. Rajasekaran

1992-01-01T23:59:59.000Z

317

Modeling the Complex Dynamics of Distributed Communities of the Web with Pretopology  

E-Print Network (OSTI)

Modeling the Complex Dynamics of Distributed Communities of the Web with Pretopology Vincent analysis of web communities. This approach is based upon the pretopological concepts of pseudoclosure through the actual limits of graph theory modeling. The problem of modeling and understanding web

318

Pseudo Dynamic Transitional Modeling of Building Heating Energy Demand Using Artificial1 Neural Network2  

E-Print Network (OSTI)

Transitional Modeling of Building Heating Energy Demand Using Artificial1 Neural Network2 Subodh Paudel a.Lecorre@mines-nantes.fr9 Abstract10 This paper presents the building heating demand prediction model with occupancy profile Institution15 building and compared its results with static and other pseudo dynamic neural network models

Paris-Sud XI, Université de

319

Model-based control strategies in the dynamic interaction of air supply and fuel cell  

E-Print Network (OSTI)

Model-based control strategies in the dynamic interaction of air supply and fuel cell M Grujicic1Ã? fuel cell temperature. The model is used to analyse the control of the fuel cell system with respect, University of Michigan, Ann Arbor, Michigan, USA Abstract: Model-based control strategies are utilized

Grujicic, Mica

320

Small-signal dynamic model of a micro-grid including conventional and electronically  

E-Print Network (OSTI)

Small-signal dynamic model of a micro-grid including conventional and electronically interfaced-signal modelling of a micro-grid system that includes conventional (rotating machine) and electronically interfaced deviations in the overall system model and provides a methodology for the analysis of autonomous micro-grid

Lehn, Peter W.

Note: This page contains sample records for the topic "dynamics models assessing" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


321

Transmission Dynamics of an Influenza Model with Age of Infection ...  

E-Print Network (OSTI)

viral treatment and drug-resistance. In this paper, we consider an influenza model which includes an age of infection. The model includes partial differential ...

2010-07-20T23:59:59.000Z

322

Quantification of model mismatch errors of the dynamic energy distribution in a stirred-tank reactor  

E-Print Network (OSTI)

QUANTIFICATION OF MODEL MISMATCH ERRORS OF THE DYNAMIC ENERGY DISTRIBUTION IN A STIRRED- TANK REACTOR A Thesis by MARK RAYMOND KIMMICH Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 198i Major Subject: Chemical Engineering QUANTIFICATION OF MODEL MISMATCH ERRORS OF THE DYNAMIC ENERGY DISTRIBUTION IN A STIRRED-TANK REACTOR A Thesis by MARK RAYMOND KIMMICH Approved as to style and content by...

Kimmich, Mark Raymond

1987-01-01T23:59:59.000Z

323

Generator Dynamic Model Validation and Parameter Calibration Using Phasor Measurements at the Point of Connection  

SciTech Connect

Disturbance data recorded by phasor measurement units (PMU) offers opportunities to improve the integrity of dynamic models. However, manually tuning parameters through play-back events demands significant efforts and engineering experiences. In this paper, a calibration method using the extended Kalman filter (EKF) technique is proposed. The formulation of EKF with parameter calibration is discussed. Case studies are presented to demonstrate its validity. The proposed calibration method is cost-effective, complementary to traditional equipment testing for improving dynamic model quality.

Huang, Zhenyu; Du, Pengwei; Kosterev, Dmitry; Yang, Steve

2013-05-01T23:59:59.000Z

324

Dynamic modeling and simulation of a solar-assisted multi-effect distillation plant  

Science Journals Connector (OSTI)

Abstract This paper presents a dynamic model of a solar-assisted multi-effect distillation (MED) plant, carrying on with the previous work “Dynamic modeling and performance of the first cell of a multi-effect distillation plant” (de la Calle et al., 2014). The dynamic model has been designed according to the experience with an experimental solar thermal desalination system erected at CIEMAT-Plataforma Solar de Almería (PSA). The mathematical formulation based on physical principles describes the main heat and mass transfer phenomena in this kind of facilities. The model was implemented using the equation-based object-oriented Modelica modeling language. Based on a modular and hierarchical modeling, different specific-phenomenon submodels have been developed. They have been interconnected between them, thus making a three level deep hierarchy. All the submodels have been calibrated and validated with experimental data. The numerical predictions show a good agreement with measured data.

Alberto de la Calle; Javier Bonilla; Lidia Roca; Patricia Palenzuela

2015-01-01T23:59:59.000Z

325

Characteristics of identifying linear dynamic models from impulse response data using Prony analysis  

SciTech Connect

The purpose of the study was to investigate the characteristics of fitting linear dynamic models to the impulse response of oscillatory dynamic systems using Prony analysis. Many dynamic systems exhibit oscillatory responses with multiple modes of oscillations. Although the underlying dynamics of such systems are often nonlinear, it is frequently possible and very useful to represent the system operating about some set point with a linear model. Derivation of such linear models can be done using two basic approaches: model the system using theoretical derivations and some linearization method such as a Taylor series expansion; or use a curve-fitting technique to optimally fit a linear model to specified system response data. Prony analysis belongs to the second class of system modeling because it is a method of fitting a linear model to the impulse response of a dynamic system. Its parallel formulation inherently makes it well suited for fitting models to oscillatory system data. Such oscillatory dynamic effects occur in large synchronous-generator-based power systems in the form of electromechanical oscillations. To study and characterize these oscillatory dynamics, BPA has developed computer codes to analyze system data using Prony analysis. The objective of this study was to develop a highly detailed understanding of the properties of using Prony analysis to fit models to systems with characteristics often encountered in power systems. This understanding was then extended to develop general rules-of-thumb'' for using Prony analysis. The general characteristics were investigated by performing fits to data from known linear models under controlled conditions. The conditions studied include various mathematical solution techniques; different parent system configurations; and a large variety of underlying noise characteristics.

Trudnowski, D.J.

1992-12-01T23:59:59.000Z

326

Characteristics of identifying linear dynamic models from impulse response data using Prony analysis  

SciTech Connect

The purpose of the study was to investigate the characteristics of fitting linear dynamic models to the impulse response of oscillatory dynamic systems using Prony analysis. Many dynamic systems exhibit oscillatory responses with multiple modes of oscillations. Although the underlying dynamics of such systems are often nonlinear, it is frequently possible and very useful to represent the system operating about some set point with a linear model. Derivation of such linear models can be done using two basic approaches: model the system using theoretical derivations and some linearization method such as a Taylor series expansion; or use a curve-fitting technique to optimally fit a linear model to specified system response data. Prony analysis belongs to the second class of system modeling because it is a method of fitting a linear model to the impulse response of a dynamic system. Its parallel formulation inherently makes it well suited for fitting models to oscillatory system data. Such oscillatory dynamic effects occur in large synchronous-generator-based power systems in the form of electromechanical oscillations. To study and characterize these oscillatory dynamics, BPA has developed computer codes to analyze system data using Prony analysis. The objective of this study was to develop a highly detailed understanding of the properties of using Prony analysis to fit models to systems with characteristics often encountered in power systems. This understanding was then extended to develop general ``rules-of-thumb`` for using Prony analysis. The general characteristics were investigated by performing fits to data from known linear models under controlled conditions. The conditions studied include various mathematical solution techniques; different parent system configurations; and a large variety of underlying noise characteristics.

Trudnowski, D.J.

1992-12-01T23:59:59.000Z

327

Assessment of solution uncertainties in single-column modeling frameworks  

SciTech Connect

Single-column models (SCMs) have been extensively promoted in recent years as an effective means to develop and test physical parameterizations targeted for more complex three-dimensional climate models. Although there are some clear advantages associated with single-column modeling, there are also some significant disadvantages, including the absence of large-scale feedbacks. Basic limitations of an SCM framework can make it difficult to interpret solutions, and at times contribute to rather striking failures to identify even first-order sensitivities as they would be observed in a global climate simulation. This manuscript will focus on one of the basic experimental approaches currently exploited by the single-column modeling community, with an emphasis on establishing the inherent uncertainties in the numerical solutions. The analysis will employ the standard physics package from the NCAR CCM3 and will illustrate the nature of solution uncertainties that arise from nonlinearities in parameterized physics. The results of this study suggest the need to make use of an ensemble methodology when conducting single-column modeling investigations.

Hack, J.J.; Pedretti, J.A.

2000-01-15T23:59:59.000Z

328

Dynamic Models for Liquid Rocket Engines with Health Monitoring Application  

E-Print Network (OSTI)

) is considered and reviewed, taking as a reference the thermodynamic model introduced by Rocketdyne

329

Dynamically dimensioned search algorithm for computationally efficient watershed model calibration  

E-Print Network (OSTI)

search (DDS), is introduced for automatic calibration of watershed simulation models. DDS is designed. Introduction [2] Almost all watershed simulation models contain effective physical and/or conceptual model. This study will focus on the automatic calibration of watershed simulation models. The results of this study

Hutter, Frank

330

Assessing the consistency between short-term global temperature trends in observations and climate model projections  

E-Print Network (OSTI)

Assessing the consistency between short-term global temperature trends in observations and climate model projections is a challenging problem. While climate models capture many processes governing short-term climate fluctuations, they are not expected to simulate the specific timing of these somewhat random phenomena - the occurrence of which may impact the realized trend. Therefore, to assess model performance, we develop distributions of projected temperature trends from a collection of climate models running the IPCC A1B emissions scenario. We evaluate where observed trends of length 5 to 15 years fall within the distribution of model trends of the same length. We find that current trends lie near the lower limits of the model distributions, with cumulative probability-of-occurrence values typically between 5 percent and 20 percent, and probabilities below 5 percent not uncommon. Our results indicate cause for concern regarding the consistency between climate model projections and observed climate behavior...

Michaels, Patrick J; Christy, John R; Herman, Chad S; Liljegren, Lucia M; Annan, James D

2013-01-01T23:59:59.000Z

331

Assessing security threat scenarios for utility-based reputation model in grids  

Science Journals Connector (OSTI)

Trust and reputation models play an important role in enabling trusted computations over large-scale distributed grids. Many models have been recently proposed and implemented within trust management systems. Nevertheless, the existing approaches usually assess performance of models in terms of resource management while less attention is paid to the analysis of security threat scenarios for such models. In this paper, we assess the most important and critical security threats for a utility-based reputation model in grids. The existing model is extended to address these threat scenarios. With simulations that were run using data collected from the EGEE Grid-Observatory project, we analyse efficiency of the utility-based reputation model against these threats.

Olga Kussul; Nataliia Kussul; Sergii Skakun

2013-01-01T23:59:59.000Z

332

Building a comprehensive quantitative risk assessment model for lung cancer  

Science Journals Connector (OSTI)

...Res, Volume 46, 2005 Building a comprehensive quantitative...including identification of multi-collinearities and...and resulted in model multi-collinearities. When...asbestos exposure, family history of LC and years...factors of emphysema, family history of LC, years...

Carol J. Etzel; Qing Zhang; Matthew Schabath; Qiong Dong; Xifeng Wu; Qingyi Wei; Margaret Spitz; and Christopher I. Amos

2005-05-01T23:59:59.000Z

333

Assessing certainty and uncertainty in riparian habitat suitability models by identifying parameters with extreme outputs  

Science Journals Connector (OSTI)

The aim of this paper is to introduce a computationally efficient uncertainty assessment approach using an index-based habitat suitability model. The approach focuses on uncertainty in ecological knowledge regarding parameters of index curves and weights. ... Keywords: Habitat model, Riparian vegetation, Suitability index, Uncertainty

Baihua Fu, Joseph H. A. Guillaume

2014-10-01T23:59:59.000Z

334

A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering  

E-Print Network (OSTI)

1 A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering Brunswick, NJ. 5 Canadian Centre for Climate Modeling and Analysis, Environment Canada, Toronto, Ontario, Canada. 6 School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada

Robock, Alan

335

Update and assessment of geothermal economic models, geothermal fluid flow and heat distribution models, and geothermal data bases  

SciTech Connect

Numerical simulation models and data bases that were developed for DOE as part of a number of geothermal programs have been assessed with respect to their overall stage of development and usefulness. This report combines three separate studies that focus attention upon: (1) economic models related to geothermal energy; (2) physical geothermal system models pertaining to thermal energy and the fluid medium; and (3) geothermal energy data bases. Computerized numerical models pertaining to the economics of extracting and utilizing geothermal energy have been summarized and catalogued with respect to their availability, utility and function. The 19 models that are discussed in detail were developed for use by geothermal operators, public utilities, and lending institutions who require a means to estimate the value of a given resource, total project costs, and the sensitivity of these values to specific variables. A number of the models are capable of economically assessing engineering aspects of geothermal projects. Computerized simulations of heat distribution and fluid flow have been assessed and are presented for ten models. Five of the models are identified as wellbore simulators and five are described as reservoir simulators. Each model is described in terms of its operational characteristics, input, output, and other pertinent attributes. Geothermal energy data bases are reviewed with respect to their current usefulness and availability. Summaries of eight data bases are provided in catalogue format, and an overall comparison of the elements of each data base is included.

Kenkeremath, D. (ed.)

1985-05-01T23:59:59.000Z

336

A Comparative Assessment of Malware Classification using Binary Texture Analysis and Dynamic Analysis  

E-Print Network (OSTI)

.ucsb.edu Vinod Yegneswaran SRI International Menlo Park, USA vinod@csl.sri.com Phillip Porras SRI International features. Further, feature extraction requires a time investment per binary that does not scale well and efficient complement to dynamic analysis. Categories and Subject Descriptors D.4.6 [Security and Protection

California at Santa Barbara, University of

337

Small-Signal Stability Assessment of Active Distribution Networks with Dynamic Loads  

E-Print Network (OSTI)

. Index Terms-- Distributed generation, eigenvalue, induction motor, small-signal stability, voltage mode-- This paper investigates small-signal stability of a distribution system with distributed generator and induction motor load, as a dynamic element. The analysis is carried out over a distribution test system

Pota, Himanshu Roy

338

Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models  

SciTech Connect

This final report summarizes research undertaken collaboratively between Princeton University, the NOAA Geophysical Fluid Dynamics Laboratory on the Princeton University campus, the State University of New York at Stony Brook, and the University of California, Los Angeles between September 1, 2000, and November 30, 2006, to do fundamental research on ocean iron fertilization as a means to enhance the net oceanic uptake of CO2 from the atmosphere. The approach we proposed was to develop and apply a suite of coupled physical-ecological-biogeochemical models in order to (i) determine to what extent enhanced carbon fixation from iron fertilization will lead to an increase in the oceanic uptake of atmospheric CO2 and how long this carbon will remain sequestered (efficiency), and (ii) examine the changes in ocean ecology and natural biogeochemical cycles resulting from iron fertilization (consequences). The award was funded in two separate three-year installments: • September 1, 2000 to November 30, 2003, for a project entitled “Ocean carbon sequestration by fertilization: An integrated biogeochemical assessment.” A final report was submitted for this at the end of 2003 and is included here as Appendix 1. • December 1, 2003 to November 30, 2006, for a follow-on project under the same grant number entitled “Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models.” This report focuses primarily on the progress we made during the second period of funding subsequent to the work reported on in Appendix 1. When we began this project, we were thinking almost exclusively in terms of long-term fertilization over large regions of the ocean such as the Southern Ocean, with much of our focus being on how ocean circulation and biogeochemical cycling would interact to control the response to a given fertilization scenario. Our research on these types of scenarios, which was carried out largely during the first three years of our project, led to several major new insights on the interaction between ocean biogeochemistry and circulation. This work, which is described in the following Section II on “Large scale fertilization,” has continued to appear in the literature over the past few years, including two high visibility papers in Nature. Early on in the first three years of our project, it became clear that small "patch-scale" fertilizations over limited regions of order 100 km diameter were much more likely than large scale fertilization, and we carried out a series of idealized patch fertilization simulations reported on in Gnanadesikan et al. (2003). Based on this paper and other results we had obtained by the end of our first three-year grant, we identified a number of important issues that needed to be addressed in the second three-year period of this grant. Section III on “patch fertilization” discusses the major findings of this phase of our research, which is described in two major manuscripts that will be submitted for publication in the near future. This research makes use of new more realistic ocean ecosystem and iron cycling models than our first paper on this topic. We have several major new insights into what controls the efficiency of iron fertilization in the ocean. Section IV on “model development” summarizes a set of papers describing the progress that we made on improving the ecosystem models we use for our iron fertilization simulations.

Jorge L. Sarmiento - Princeton PI, Anand Gnanadesikan - Princeton Co-I, Nicolas Gruber - UCLA PI, Xin Jin - UCLA PostDoc, Robert Armstrong - SUNY /Stony Brook Consultant

2007-06-21T23:59:59.000Z

339

Assessment  

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

Genetic Genetic Variability of Cell Wall Degradability for the Selection of Alfalfa with Improved Saccharification Efficiency Marc-Olivier Duceppe & Annick Bertrand & Sivakumar Pattathil & Jeffrey Miller & Yves Castonguay & Michael G. Hahn & Réal Michaud & Marie-Pier Dubé # Her Majesty the Queen in Right of Canada 2012 Abstract Alfalfa (Medicago sativa L.) has a high potential for sustainable bioethanol production, particularly because of its low reliance on N fertilizer. We assessed near-infrared reflec- tance spectroscopy (NIRS) as a high-throughput technique to measure cell wall (CW) degradability in a large number of lignified alfalfa stem samples. We also used a powerful immu- nological approach, glycome profiling, and chemical analyses to increase our knowledge of the composition of CW poly- saccharides of alfalfa stems with various levels

340

Variational Inference in Stochastic Dynamic Environmental Models Dan Cornford1  

E-Print Network (OSTI)

on related phenomena, such as flooding and storm damage, and on the spread of pollutants. The models needed of the atmosphere even at the resolution of the model. This is especially problematic if the simulation

Roulstone, Ian

Note: This page contains sample records for the topic "dynamics models assessing" 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

A dynamic process model of a natural gas combined cycle -- Model development with startup and shutdown simulations  

SciTech Connect

Research in dynamic process simulation for integrated gasification combined cycles (IGCC) with carbon capture has been ongoing at the National Energy Technology Laboratory (NETL), culminating in a full operator training simulator (OTS) and immersive training simulator (ITS) for use in both operator training and research. A derivative work of the IGCC dynamic simulator has been a modification of the combined cycle section to more closely represent a typical natural gas fired combined cycle (NGCC). This paper describes the NGCC dynamic process model and highlights some of the simulator’s current capabilities through a particular startup and shutdown scenario.

Liese, Eric [U.S. DOE; Zitney, Stephen E. [U.S. DOE

2013-01-01T23:59:59.000Z

342

Control Oriented Dynamic Modeling of a Turbocharged Diesel Engine  

Science Journals Connector (OSTI)

To build a precise model is a key issue in fulfilling on optimal control of the turbocharged diesel engine. Meanvalue model has been extensively used for engine control, but neglects the scavenging efficiency. On the basis of carefully considering air-fuel ... Keywords: Diesel engine, mean-value model, AFR

Haiyan Wang; Jundong Zhang

2006-10-01T23:59:59.000Z

343

Model for quantitative risk assessment on naturally ventilated metering-regulation stations for natural gas  

Science Journals Connector (OSTI)

Abstract The paper presents a model for quantitative risk assessment on metering stations and metering-regulation stations for natural gas with natural ventilation. The model enables the assessment of risk for people who live in the vicinity of these stations and complements the existing models for risk assessment on natural gas pipelines. It is based on risk assessment methods suggested in relevant guides, recommendations and standards. Explosion and jet fire are considered as major hazardous events and are modelled according to analytical models and empirical data. Local or other accessible databases are used for modelling of event frequencies and ignition probabilities. A case study on a sample station is carried out. For each hazardous event, fault tree and event tree analysis is performed. Results show influence of each hazardous event on the whole risk relative to the distance from the hazardous source. Ventilation is found to be a significant factor in determination of risk magnitude; its influence on individual risk is presented in a quantitative way. The model should be of use for pipeline operators as well as for environmental- and urban planners.

Tom Bajcar; Franc Cimerman; Brane Širok

2014-01-01T23:59:59.000Z

344

Improvement of modelling capabilities for assessing urban contamination : The EMRAS Urban Remediation Working Group.  

SciTech Connect

The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modeling for Radiation Safety (EMRAS) programme was established to improve modeling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.

Thiessen, K. M.; Batandjieva, B.; Andersson, K. G.; Arkhipov, A.; Charnock, T. W.; Gallay, F.; Gaschak, S.; Golikov, V.; Hwang, W. T.; Kaiser, J. C.; Kamboj, S.; Steiner, M.; Tomas, J.; Trifunovic, D.; Yu, C.; Ziemer, R. L.; Zlobenko, B.; Environmental Science Division; SENES Oak Ridge; IAEA; Riso National Lab.; Chernobyl Center for Nuclear Safety; Health Protection Agency; IRSN; Inst. of Radiation Hygene of the Ministry of Public Health, Russian Federation; KAERI, Republic of Korea; GSF, Germany; BfS, Germany; CPHR, Cuba; State Office for Radiation Protection, Croatia; AECL, Canada; National Academy of Science, Ukraine

2008-01-01T23:59:59.000Z

345

Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty  

SciTech Connect

We propose an approach for imaging the dynamics of complex hydrological processes. The evolution of electrically conductive fluids in porous media is imaged using time-lapse electrical resistance tomography. The related dynamic inversion problem is solved using Bayesian filtering techniques, that is, it is formulated as a sequential state estimation problem in which the target is an evolving posterior probability density of the system state. The dynamical inversion framework is based on the state space representation of the system, which involves the construction of a stochastic evolution model and an observation model. The observation model used in this paper consists of the complete electrode model for ERT, with Archie's law relating saturations to electrical conductivity. The evolution model is an approximate model for simulating flow through partially saturated porous media. Unavoidable modeling and approximation errors in both the observation and evolution models are considered by computing approximate statistics for these errors. These models are then included in the construction of the posterior probability density of the estimated system state. This approximation error method allows the use of approximate - and therefore computationally efficient - observation and evolution models in the Bayesian filtering. We consider a synthetic example and show that the incorporation of an explicit model for the model uncertainties in the state space representation can yield better estimates than a frame-by-frame imaging approach.

Lehikoinen, A.; Huttunen, J.M.J.; Finsterle, S.; Kowalsky, M.B.; Kaipio, J.P.

2009-08-01T23:59:59.000Z

346

CFD modeling of two-stage ignition in a rapid compression machine: Assessment of zero-dimensional approach  

SciTech Connect

In modeling rapid compression machine (RCM) experiments, zero-dimensional approach is commonly used along with an associated heat loss model. The adequacy of such approach has not been validated for hydrocarbon fuels. The existence of multi-dimensional effects inside an RCM due to the boundary layer, roll-up vortex, non-uniform heat release, and piston crevice could result in deviation from the zero-dimensional assumption, particularly for hydrocarbons exhibiting two-stage ignition and strong thermokinetic interactions. The objective of this investigation is to assess the adequacy of zero-dimensional approach in modeling RCM experiments under conditions of two-stage ignition and negative temperature coefficient (NTC) response. Computational fluid dynamics simulations are conducted for n-heptane ignition in an RCM and the validity of zero-dimensional approach is assessed through comparisons over the entire NTC region. Results show that the zero-dimensional model based on the approach of 'adiabatic volume expansion' performs very well in adequately predicting the first-stage ignition delays, although quantitative discrepancy for the prediction of the total ignition delays and pressure rise in the first-stage ignition is noted even when the roll-up vortex is suppressed and a well-defined homogeneous core is retained within an RCM. Furthermore, the discrepancy is pressure dependent and decreases as compressed pressure is increased. Also, as ignition response becomes single-stage at higher compressed temperatures, discrepancy from the zero-dimensional simulations reduces. Despite of some quantitative discrepancy, the zero-dimensional modeling approach is deemed satisfactory from the viewpoint of the ignition delay simulation. (author)

Mittal, Gaurav [Department of Mechanical Engineering, The University of Akron, Akron, OH 44325 (United States); Raju, Mandhapati P. [General Motor R and D Tech Center, Warren, MI 48090 (United States); Sung, Chih-Jen [Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269 (United States)

2010-07-15T23:59:59.000Z

347

Dynamical System Approach to Cosmological Models with a Varying Speed of Light  

E-Print Network (OSTI)

Methods of dynamical systems have been used to study homogeneous and isotropic cosmological models with a varying speed of light (VSL). We propose two methods of reduction of dynamics to the form of planar Hamiltonian dynamical systems for models with a time dependent equation of state. The solutions are analyzed on two-dimensional phase space in the variables $(x, \\dot{x})$ where $x$ is a function of a scale factor $a$. Then we show how the horizon problem may be solved on some evolutional paths. It is shown that the models with negative curvature overcome the horizon and flatness problems. The presented method of reduction can be adopted to the analysis of dynamics of the universe with the general form of the equation of state $p=\\gamma(a)\\epsilon$. This is demonstrated using as an example the dynamics of VSL models filled with a non-interacting fluid. We demonstrate a new type of evolution near the initial singularity caused by a varying speed of light. The singularity-free oscillating universes are also admitted for positive cosmological constant. We consider a quantum VSL FRW closed model with radiation and show that the highest tunnelling rate occurs for a constant velocity of light if $c(a) \\propto a^n$ and $-1 < n \\le 0$. It is also proved that the considered class of models is structurally unstable for the case of $n < 0$.

Marek Szydlowski; Adam Krawiec

2002-12-16T23:59:59.000Z

348

Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model  

SciTech Connect

Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People's Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

2012-01-15T23:59:59.000Z

349

Synchronized Phasor Data for Analyzing Wind Power Plant Dynamic Behavior and Model Validation  

SciTech Connect

The U.S. power industry is undertaking several initiatives that will improve the operations of the power grid. One of those is the implementation of 'wide area measurements' using phasor measurement units (PMUs) to dynamically monitor the operations and the status of the network and provide advanced situational awareness and stability assessment. This project seeks to obtain PMU data from wind power plants and grid reference points and develop software tools to analyze and visualize synchrophasor data for the purpose of better understanding wind power plant dynamic behaviors under normal and contingency conditions.

Wan, Y. H.

2013-01-01T23:59:59.000Z

350

Advances in National Capabilities for Consequence Assessment Modeling of Airborne Hazards  

SciTech Connect

This paper describes ongoing advancement of airborne hazard modeling capabilities in support of multiple agencies through the National Atmospheric Release Advisory Center (NARAC) and the Interagency Atmospheric Modeling and Atmospheric Assessment Center (IMAAC). A suite of software tools developed by Lawrence Livermore National Laboratory (LLNL) and collaborating organizations includes simple stand-alone, local-scale plume modeling tools for end user's computers, Web- and Internet-based software to access advanced 3-D flow and atmospheric dispersion modeling tools and expert analysis from the national center at LLNL, and state-of-the-science high-resolution urban models and event reconstruction capabilities.

Nasstrom, J; Sugiyama, G; Foster, K; Larsen, S; Kosovic, B; Eme, B; Walker, H; Goldstein, P; Lundquist, J; Pobanz, B; Fulton, J

2007-11-26T23:59:59.000Z

351

Mathematical modeling of irreversible dynamic deformation, micro- and macrofracture of materials and structures  

National Nuclear Security Administration (NNSA)

7: Material Phase Transition, Modeling, and Others 7: Material Phase Transition, Modeling, and Others Mathematical Modeling of Irreversible Dynamic Deformation, Micro- and Macrofracture of Materials and Structures P. P. Zakharov and A. B. Kiselev All-Russia Research Institute of Automatics, Moscow 125412, Russia Thermomechanical processes, which proceed in deformable solids under intensive dynamic loading, consist of mechanical, thermal and structural ones, which correlate themselves. The structural processes involve the formation, motion and interaction of defects in metallic crystals, phase transitions, the breaking of bonds between molecules in polymers, the accumulation of microstructural damages (pores, cracks), etc. Irreversible deformations, zones of adiabatic shear and microfractures are caused by these

352

Dynamic behavior of the monomermonomer surface reaction model with adsorbate interactions  

E-Print Network (OSTI)

Dynamic behavior of the monomer­monomer surface reaction model with adsorbate interactions model with an adsorbate interaction term is studied. An epidemic analysis of the poisoning times (tp between the concentration of molecules adsorbed on the surface and the rate of adsorp- tion

Voigt, Chris

353

A. Ford and H. Flynn: Statistical Screening of Models 273 Statistical screening of system dynamics  

E-Print Network (OSTI)

in the information spectrum in Figure 1. Hard sources include physical laws and the results of controlled experimentsA. Ford and H. Flynn: Statistical Screening of Models 273 Statistical screening of system dynamics models Andrew Forda * and Hilary Flynnb Abstract This paper describes a pragmatic method of searching

Ford, Andrew

354

Modeling a Continuous Dynamic Task Wayne D. Gray, Michael J. Schoelles, & Wai-Tat Fu  

E-Print Network (OSTI)

Modeling a Continuous Dynamic Task Wayne D. Gray, Michael J. Schoelles, & Wai-Tat Fu Human Factors in several ways. Modeling the impact of one such difference raised theoretical issues in motor movement and attention. For motor movement, the issue concerned the functional shape and size of a target

Gray, Wayne

355

A simple Markov model of sodium channels with a dynamic threshold  

Science Journals Connector (OSTI)

Characteristics of action potential generation are important to understanding brain functioning and, thus, must be understood and modeled. It is still an open question what model can describe concurrently the phenomena of sharp spike shape, the spike ... Keywords: Conductance-based neurons, Divisive effect, Dynamic patch-clamp, Sodium channels, Spike shape, Spike threshold

A. V. Chizhov; E. Yu. Smirnova; K. Kh. Kim; A. V. Zaitsev

2014-08-01T23:59:59.000Z

356

FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY  

E-Print Network (OSTI)

FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY Prabir Daripa. Relevance of this HS model based result to EOR is established by performing direct numerical simulations of fully developed tertiary displacement in porous media. Results of direct numer- ical simulation

Daripa, Prabir

357

Protecting the African elephant: A dynamic bioeconomic model of ivory trade  

E-Print Network (OSTI)

Protecting the African elephant: A dynamic bioeconomic model of ivory trade G. Cornelis van Kooten Accepted 25 May 2008 Available online 7 July 2008 Keywords: Economics Elephant conservation Ivory trade ban on the protection of the African elephant (Laxadonta africana). The model consists of four ivory exporting regions

358

A model of sediment resuspension and transport dynamics in southern Lake Michigan  

E-Print Network (OSTI)

A model of sediment resuspension and transport dynamics in southern Lake Michigan Jing Lou-three-dimensional suspended sediment transport model was developed and generalized to include combined wave-current effects to study bottom sediment resuspension and transport in southern Lake Michigan. The results from a three

359

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel  

E-Print Network (OSTI)

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller Bachelors of Engineering, University in a polymer electrolyte fuel cell is a critical issue in ensuring high cell performance. The water production

Victoria, University of

360

Modeling of quasistatic and dynamic load responses of filled viscoelastic materials  

E-Print Network (OSTI)

are typically used for static finite element analysis (see [9]). The CRSC/Lord team worked, both theoreticallyModeling of quasi­static and dynamic load responses of filled viscoelastic materials H.T. Banks factors to the complications arising in the process of formulating models. Damping is highly complex

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361

Transient dynamics and food–web complexity in the Lotka–Volterra cascade model  

Science Journals Connector (OSTI)

...research-article Transient dynamics and food-web complexity in the Lotka-Volterra cascade...behaviour near equilibrium of model food webs correlate with their short-term transient...Lotka-Volterra cascade model of food webs provide the first evidence to answer this...

2001-01-01T23:59:59.000Z

362

Towards a Formal Semantics for a Structurally Dynamic Noncausal Modelling Language  

E-Print Network (OSTI)

, many of these languages are referred to as object-oriented mod- elling languages. Modelica [23] is oneTowards a Formal Semantics for a Structurally Dynamic Noncausal Modelling Language John Capper, UK nhn@cs.nott.ac.uk Abstract Modelling and simulation languages are evolving rapidly to sup- port

Nilsson, Henrik

363

Integrating Models and Simulations of Continuous Dynamics into SysML  

E-Print Network (OSTI)

and the corresponding Modelica models; and the integration of simulation experiments with other SysML constructsIntegrating Models and Simulations of Continuous Dynamics into SysML Thomas Johnson1 Christiaan J.J. Paredis1 Roger Burkhart2 1 Systems Realization Laboratory The G. W. Woodruff School of Mechanical

364

Dynamic Models for Wind Turbines and Wind Power Plants  

SciTech Connect

The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

Singh, M.; Santoso, S.

2011-10-01T23:59:59.000Z

365

Patch Occupancy Models of Metapopulation Dynamics: Ef?cient ...  

E-Print Network (OSTI)

with spatial data on patch occupancyv The latter data are more readily available. ... and it can be adapted to any stochastic patch occupancy model of ...

366

Transmission Dynamics of an Influenza Model with Vaccination and ...  

E-Print Network (OSTI)

Jun 30, 2009 ... promised if drug-resistant strains arise. In this paper, we develop a mathematical model to explore the impact of vaccination and antiviral ...

2010-01-15T23:59:59.000Z

367

Dynamic reliability and risk assessment of the accident localization system of the Ignalina NPP RBMK-1500 reactor  

Science Journals Connector (OSTI)

The paper presents reliability and risk analysis of the RBMK-1500 reactor accident localization system (ALS) (confinement), which prevents radioactive releases to the environment. Reliability of the system was estimated and compared by two methods: the conventional fault tree method and an innovative dynamic reliability model, based on stochastic differential equations. Frequency of radioactive release through ALS was also estimated. The results of the study indicate that conventional fault tree modeling techniques in this case apply high degree of conservatism in the system reliability estimates. One of the purposes of the ALS reliability study was to demonstrate advantages of the dynamic reliability analysis against the conventional fault/event tree methods. The Markovian framework to deal with dynamic aspects of system behavior is presented. Although not analyzed in detail, the framework is also capable of accounting for non-constant component failure rates. Computational methods are proposed to solve stochastic differential equations, including analytical solution, which is possible only for relatively small and simple systems. Other numerical methods, like Monte Carlo and numerical schemes of differential equations are analyzed and compared. The study is finalized with concluding remarks regarding both the studied system reliability and computational methods used.

V. Kopustinskas; J. Augutis; S. Rimkevi?ius

2005-01-01T23:59:59.000Z

368

Dynamic model of anisotropic x-ray refraction  

Science Journals Connector (OSTI)

General mechanisms of anisotropic x-ray refraction at the resonance energy are investigated on the basis of dynamic-scattering theory. The deductions show that x rays within the crystals that have anisotropic susceptibility are completely polarized and have two elliptical polarization states. Analytical expressions of the elliptical axes, refractive indices, and absorption coefficients for these two types of polarized waves are obtained in terms of the anisotropic components of the susceptibility tensor. Anisotropic birefringence and dichroism effects associated with the polarization properties of the x-ray waves are also illustrated theoretically.

X. R. Huang, Yong Li, W. J. Liu, and S. S. Jiang

1997-11-01T23:59:59.000Z

369

Relativistic Dynamical Collapse Model for a Scalar Field  

E-Print Network (OSTI)

A natural generalization of the CSL (Continuous Spontaneous Localization) theory of dynamical collapse is applied to a relativistic quantum scalar field $\\phi({\\bf x},t)$. It is shown that the modified Schr\\"odinger equation is relativistically invariant, that the probabilities associated to all possible values of the classical scalar random field $w({\\bf x},t)$ (which determines the eventual state of collapse) add up to 1, that there is no energy production out of the vacuum and, in the limit of large time, the collapse is toward eigenstates of $\\phi({\\bf x},0)$.

Philip Pearle

2014-04-26T23:59:59.000Z

370

Dynamical instabilities in density-dependent hadronic relativistic models  

SciTech Connect

Unstable modes in asymmetric nuclear matter (ANM) at subsaturation densities are studied in the framework of relativistic mean-field density-dependent hadron models. The size of the instabilities that drive the system are calculated and a comparison with results obtained within the nonlinear Walecka model is presented. The distillation and antidistillation effects are discussed.

Santos, A. M.; Brito, L.; Providencia, C. [Centro de Fisica Teorica, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

2008-04-15T23:59:59.000Z

371

Modeling dynamic conditional correlations in WTI oil forward and futures returns  

Science Journals Connector (OSTI)

This paper estimates the dynamic conditional correlations in the daily returns on West Texas Intermediate (WTI) oil forward and futures prices from 3 January 1985 to 16 January 2004, using recently developed multivariate conditional volatility models. We find that the dynamic conditional correlations can vary dramatically, being negative in four of ten cases and being close to zero in another five cases. Only in the case of the dynamic volatilities of the three-month and six-month futures returns is the range of variation relatively narrow, namely (0.832, 0.996).

Alessandro Lanza; Matteo Manera; Michael McAleer

2006-01-01T23:59:59.000Z

372

Dynamic modeling of an integrated air-to-air heat pump using Modelica  

Science Journals Connector (OSTI)

Heat pump systems have gained significant market shares in Europe recently. The control strategy is an asset for the efficient operation of these thermodynamic systems; especially with compact integrated components. The predictive control, which allows fast system stabilization, is based on the description of the system physical behavior. Thus, dynamic modeling is needed for the development of such control. The model has to represent the system response to usual external perturbations met during current operation such as the variation of air temperature and air mass flow rate. The aim of this paper is to present a dynamic model of a thermodynamic system developed in the Dymola environment, which is an object-oriented modeling environment. The heat-pump components are created separately as individual objects, and then connected to form the system. The model of each component is described and the responses to different perturbations are detailed. Simulation results are compared to test results in order to validate the model.

S. Mortada; A. Zoughaib; D. Clodic; C. Arzano-Daurelle

2012-01-01T23:59:59.000Z

373

A hybrid dynamic and fuzzy time series model for mid-term power load forecasting  

Science Journals Connector (OSTI)

Abstract A new hybrid model for forecasting the electric power load several months ahead is proposed. To allow for distinct responses from individual load sectors, this hybrid model, which combines dynamic (i.e., air temperature dependency of power load) and fuzzy time series approaches, is applied separately to the household, public, service, and industrial sectors. The hybrid model is tested using actual load data from the Seoul metropolitan area, and its predictions are compared with those from two typical dynamic models. Our investigation shows that, in the case of four-month forecasting, the proposed model gives the actual monthly power load of every sector with only less than 3% absolute error and satisfactory reduction of forecasting errors compared to other models from previous studies.

Woo-Joo Lee; Jinkyu Hong

2015-01-01T23:59:59.000Z

374

Dynamical phase space from a SO(d,d) matrix model  

E-Print Network (OSTI)

It is shown that a matrix model with SO($d,d$) global symmetry is derived from a generalized Yang-Mills theory on the standard Courant algebroid. This model keeps all the positive features of the well-studied type IIB matrix model, and it has many additional welcome properties. We show that it does not only capture the dynamics of spacetime, but it should be associated with the dynamics of phase space. This is supported by a large set of classical solutions of its equations of motion, which corresponds to phase spaces of noncommutative curved manifolds and points to a new mechanism of emergent gravity. The model possesses an additional symmetry that exchanges positions and momenta, in analogy to quantum mechanics. It is argued that the emergence of phase space in the model is an essential feature for the investigation of the precise relation of matrix models to string theory and quantum gravity.

Athanasios Chatzistavrakidis

2014-07-25T23:59:59.000Z

375

Dynamic modeling of a single-stage downward firing, entrained flow gasifier  

SciTech Connect

The gasifier is the heart of the integrated gasification combined cycle (IGCC), a technology that has emerged as an attractive alternative to conventional coal-fired power plant technology due to its higher efficiency and cleaner environmental performance especially with the option of CO{sub 2} capture and sequestration. Understanding the optimal performance of the gasifier is therefore paramount for the efficient operation of IGCC power plants. Numerous gasifier models of varying complexity have been developed to study the various aspects of gasifier performance. These range from simple one-dimensional (1D) process-type models to rigorous higher order 2-3D models based on computational fluid dynamics (CFD). Whereas high-fidelity CFD models can accurately predict most key aspects of gasifier performance, they are computationally expensive and typically take hours to days to execute on high-performance computers. Therefore, faster 1D partial differential equation (PDE)-based models are required for use in dynamic simulation studies, control system analysis, and training applications. A number of 1D gasifier models can be found in the literature, but most are steady-state models that have limited application in the practical operation of the gasifier. As a result, 1D PDE-based dynamic models are needed to further study and predict gasifier performance under a wide variety of process conditions and disturbances. In the current study, a 1D transient model of a single-stage downward-fired GE/Texaco-type entrained-flow gasifier has been developed. The model comprises mass, momentum and energy balances for the gas and solid phases. The model considers the initial gasification processes of water evaporation and coal devolatilization. In addition, the key heterogeneous and homogeneous chemical reactions have been modeled. The resulting time-dependent PDE model is solved using the well-known method of lines approach in Aspen Custom Modeler®, whereby the PDEs in the spatial domain are discretized and the resulting differential algebraic equations (DAEs) are then integrated over time using a dynamic integrator. The dynamic response results of the gasifier performance parameters to certain disturbances commonly encountered during practical operation are presented. These disturbances include ramp and step changes to input variables such as coal flow rate, oxygen-to-coal ratio and water-to-coal ratio among others. Comparison of model predictions to available dynamic data will also be discussed.

Kasule, J., Turton, R., Bhattacharyya, D., Zitney, S.

2012-01-01T23:59:59.000Z

376

Dynamic  

Office of Legacy Management (LM)

Dynamic Dynamic , and Static , Res.ponse of the Government Oil Shale Mine at ' , . , Rifle, Colorado, to the Rulison Event. , . ; . . DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. p ( y c - - a 2-1 0 -4- REPORT AT (29-2) 914 USBM 1 0 0 1 UNITED STATES DEPARTMENT O F THE I NTERIOR BUREAU OF MINES e s.09 P. L. R U S S E L L RESEARCH D l RECTOR Februory 2, lB7O DYNAMIC AND STATIC RESPONSE 'OF THE GOVERNMENT OIL SHALE MINE A T RIFLE, COLORADO, T O THE, RULISON EVENT ORDER FROM CFSTl A S ~ B ~ &J C / This page intentionally left blank CONTENTS Page . . . . . . . . . . . . . . . . . . . . . . . . . H i s t o r i c . a l Des c r i p t i o n 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3

377

Development of microbial-enzyme-mediated decomposition model parameters through steady-state and dynamic analyses  

SciTech Connect

We developed a Microbial-ENzyme-mediated Decomposition (MEND) model, based on the Michaelis-Menten kinetics, that describes the dynamics of physically defined pools of soil organic matter (SOC). These include particulate, mineral-associated, dissolved organic matter (POC, MOC, and DOC, respectively), microbial biomass, and associated exoenzymes. The ranges and/or distributions of parameters were determined by both analytical steady-state and dynamic analyses with SOC data from the literature. We used an improved multi-objective parameter sensitivity analysis (MOPSA) to identify the most important parameters for the full model: maintenance of microbial biomass, turnover and synthesis of enzymes, and carbon use efficiency (CUE). The model predicted an increase of 2 C (baseline temperature =12 C) caused the pools of POC-Cellulose, MOC, and total SOC to increase with dynamic CUE and decrease with constant CUE, as indicated by the 50% confidence intervals. Regardless of dynamic or constant CUE, the pool sizes of POC, MOC, and total SOC varied from 8% to 8% under +2 C. The scenario analysis using a single parameter set indicates that higher temperature with dynamic CUE might result in greater net increases in both POC-Cellulose and MOC pools. Different dynamics of various SOC pools reflected the catalytic functions of specific enzymes targeting specific substrates and the interactions between microbes, enzymes, and SOC. With the feasible parameter values estimated in this study, models incorporating fundamental principles of microbial-enzyme dynamics can lead to simulation results qualitatively different from traditional models with fast/slow/passive pools.

Wang, Gangsheng [ORNL; Post, Wilfred M [ORNL; Mayes, Melanie [ORNL

2013-01-01T23:59:59.000Z

378

Modeling Equilibrium Dynamics of the Benguela Current System  

Science Journals Connector (OSTI)

The Regional Ocean Modeling System (ROMS) is used to systematically investigate equilibrium conditions and seasonal variations of the Benguela system at a resolution of 9 km, including both the large-scale offshore flow regime and the ...

Jennifer Veitch; Pierrick Penven; Frank Shillington

2010-09-01T23:59:59.000Z

379

Investigating the dynamic behavior of biochemical networks using model families  

Science Journals Connector (OSTI)

......computing technology, a high performance computing environment is achieved...the models, the usage of high performance computing is mandatory (see Section...development of MMT2 is high performance computing. On the other hand, MMT2......

Marc Daniel Haunschild; Bernd Freisleben; Ralf Takors; Wolfgang Wiechert

2005-04-01T23:59:59.000Z

380

Final Environmental Assessment for the Proposed Consolidation of Certain Dynamic Experimentation Activities at the Two-Mile Mesa Complex Los Alamos National Laboratory, Los Alamos, New Mexico  

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

47 47 Final Environmental Assessment for the Proposed Consolidation of Certain Dynamic Experimentation Activities at the Two-Mile Mesa Complex Los Alamos National Laboratory, Los Alamos, New Mexico November 3, 2003 Department of Energy National Nuclear Security Administration Los Alamos Site Office Environmental Assessment for the Proposed DX Division Strategic Facility Plan at LANL DOE LASO November 3, 2003 iii Contents Acronyms and Terms................................................................................................................................vii Executive Summary ...................................................................................................................................xi 1.0 Purpose and Need

Note: This page contains sample records for the topic "dynamics models assessing" 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

A computer-aided modelling analogue for lattice dynamics  

Science Journals Connector (OSTI)

A useful methodology to study lattice dynamics is presented in this paper. Our method is based on the analogous behaviour of electromagnetic waves in transmission lines. The parameters analysed include the optical and acoustical branches and the frequency gap. The electrical circuit is solved using commercial software (MicroCap ); therefore, our methodology would be easily implemented on different systems. Resumen. En este trabajo se presenta una metodología útil para estudiar dinámica de redes. Nuestro método se basa en el comportamiento análogo de las ondas electromagnéticas en las líneas de transmición. Los parámetros analizados incluyen las ramas óptica y acústica y el gap de frecuencia. El circuito eléctrico es resuelto utlizando un software comercial (MicroCap ); por lo que nuestra metodologiá puede ser fácilmente implementada en diferentes sistemas.

Daniel Vega; Sergio Vera; Alfredo Juan

1997-01-01T23:59:59.000Z

382

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine  

E-Print Network (OSTI)

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine Abstract-- The LuGre dynamic point contact friction model for the two-dimensional translation of a body on a surface has been used in the past to derive a model for the friction forces

Tsiotras, Panagiotis

383

Dynamic modelling of MSF plants for automatic control and simulation purposes: a survey  

Science Journals Connector (OSTI)

The successful development of a control system requires an appropriate definition of the control structure (i.e., selection of output, input and disturbance variables) and an efficient dynamical model on which the design, analysis and evaluation can be carried out. Thus, the confidence in the obtained results depends on the validity of the control structure and of the model used. For multistage flash (MSF) desalination processes, several dynamical models can be found in the literature. However, most of them are not suitable for analysis and control design purposes because they bring too many variables into play. The variables, which are sharing in the control system, normally constitute a reduced subset of the total variables that can be defined in the process. Moreover, a dynamical model suitable for control is simpler than the model derived from the physics of the underlying process. Hence, the selection of variables and the model building from the point of view of control design presents a compromise between the indispensable information contained in the model and the mathematical complexity proper of the design. In this paper, different models from the literature are analysed. Their advantages and drawbacks are described taking into account simulation and automatic control purposes. Moreover, a set of wished modelling facilities from the control engineer point of view is highlighted. Finally, a block-oriented library for Matlab/Simulink is presented, so that different plant configurations can be implemented as block diagram to simulate the system and to test control algorithms.

Adrian Gambler; Essameddin Badreddin

2004-01-01T23:59:59.000Z

384

Modeling and dynamic performance evaluation of target capture in robotic systems  

SciTech Connect

In this paper, a dynamic system consisting of a robot manipulator and a target is analyzed. The target is considered in a general way as a dynamic subsystem having finite mass and moments of inertia (e.g., a rigid body or a second robot). The situation investigated is when the robot establishes interaction with the target in such a way that it intercepts and captures a reference element of the target. The analysis of target capture is divided into three phases in terms of time: the precapture, free motion (finite motion); the transition from free to constrained motion in the vicinity of interception and capture (impulsive motion); and the postcapture, constrained motion (finite motion). The greatest attention is paid to the analysis of the phase of transition, the impulsive motion, and dynamics of the system. Based on the use of impulsive constraints and the Jourdainian formulation of analytical dynamics, a novel approach is proposed for the dynamic modeling of target capture by a robot manipulator. The proposed approach is suitable to handle both finite and impulsive motions in a common analytical framework. Based on the dynamic model developed and using a geometric representation of the system's dynamics, a detailed analysis and a performance evaluation framework are presented for the phase of transition. Both rigid and structurally flexible models of robots are considered. For the performance evaluation analyses, two main concepts are proposed and corresponding performance measures are derived. These tools may be used in the analysis, design, and control of time-varying robotic systems. The dynamic system of a three-link robot arm capturing a rigid body is used to illustrate the material presented.

Koevecses, J.; Cleghorn, W.L.; Fenton, R.G.

2000-04-01T23:59:59.000Z

385

Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment  

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

LTR-2012/390 LTR-2012/390 Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment R. E. Stoller, A. V. Barashev, and S. I. Golubov Materials Science and Technology Division Oak Ridge National Laboratory Prepared for: Light Water Reactor Sustainability Program Office of Nuclear Energy, Science and Technology U.S. Department of Energy September 2012 ORNL/LTR-2012/390 1 Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment Abstract Recent experimental observations have made it clear that cavity formation can occur in light-water reactor internal components fabricated from austenitic stainless during the course of their service life. In order to assess the potential for cavity swelling

386

Validation of a Cognitive Diagnostic Model Across Multiple Forms of a Reading Comprehension Assessment  

E-Print Network (OSTI)

VALIDATION OF A COGNITIVE DIAGNOSTIC MODEL ACROSS MULTIPLE FORMS OF A READING COMPREHENSION ASSESSMENT by Amy K. Clark Submitted to the graduate degree... program in the Department of Psychology and Research in Education and the Graduate Faculty of the University of Kansas in partial fulfillment of the requirements for the...

Clark, Amy K

2013-12-31T23:59:59.000Z

387

Assessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using Positive and  

E-Print Network (OSTI)

July 15, 1999 #12;Abstract Much of the evidence for health e ects of particulate air pollution has come. We thus refer to the `air pollution hypothesis' to describe increased risk of health outcomes dueAssessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using

Washington at Seattle, University of

388

Ex-plant consequence assessment for NUREG-1150: Models, typical results, uncertainties  

SciTech Connect

The assessment of ex-plant consequences for NUREG-1150 source terms was performed using the MELCOR Accident Consequence Code System (MACCS). This paper will briefly discuss the following elements of MACCS consequence calculations: input data, phenomena modeled, computational framework, typical results, controlling phenomena, and uncertainties. Wherever possible, NUREG-1150 results will be used to illustrate the discussion. 28 refs., 14 figs., 6 tabs.

Sprung, J.L.

1987-01-01T23:59:59.000Z

389

Cognitive Assessment Models with Few Assumptions, and Connections with Nonparametric IRT  

E-Print Network (OSTI)

Cognitive Assessment Models with Few Assumptions, and Connections with Nonparametric IRT Brian of the monotonicity conditions discussed in Section 4. #12;Abstract In recent years, as cognitive theories of learning" on student achievement relative to theory-driven lists of examinee skills, beliefs and other cognitive

Junker, Brian

390

Refinement of weed risk assessments for biofuels using Camelina sativa as a model species  

E-Print Network (OSTI)

Refinement of weed risk assessments for biofuels using Camelina sativa as a model species Philip B and Environmental Sciences, Montana State University, PO Box 173120, Bozeman, MT 59717-3120, USA Summary 1. Biofuel. However, concerns have been raised on the invasiveness of biofuel feedstocks. Estimating invasion

Peterson, Robert K. D.

391

Uncertainty Analysis of the Adequacy Assessment Model of a Distributed Generation System  

E-Print Network (OSTI)

of evidence theory, the hybrid propagation approach is introduced. A demonstration is given on a DG system enables end-users to install renewable generators (e.g. solar generators and wind turbines) on1 Uncertainty Analysis of the Adequacy Assessment Model of a Distributed Generation System Yanfu Li

Paris-Sud XI, Université de

392

Dynamic measurement and modeling of the Casimir force at the nanometer scale  

SciTech Connect

We present a dynamic method for measurement of the Casimir force with an atomic force microscope (AFM) with a conventional AFM tip. With this method, originally based on the phase of vibration of the AFM tip, we are able to verify the Casimir force at distances of nearly 6 nm with an AFM tip that has a radius of curvature of nearly 100 nm. Until now dynamic methods have been done using large metal spheres at greater distances. Also presented is a theoretical model based on the harmonic oscillator, including nonidealities. This model accurately predicts the experimental data.

Kohoutek, John; Wan, Ivy Yoke Leng; Mohseni, Hooman [Bio-Inspired Sensors and Optoelectronics Laboratory (BISOL), EECS, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States)

2010-02-08T23:59:59.000Z

393

Lurking Pathway Prediction And Pathway ODE Model Dynamic Analysis  

E-Print Network (OSTI)

regulated proteins in the transduction pro- cess. And by modeling the CCL2 pathway in MTB infected cells, J N K , cM Y C and P LC showed as the most significant modules. Hence, the drug treatments inhibit- ing J N K , cM Y C and P LC would effectively...

Zhang, Rengjing

2013-11-18T23:59:59.000Z

394

Isotope uptake dynamics in the Ostwald ripening model of recrystallization  

E-Print Network (OSTI)

The article is withdrawn since we decided not to publish it in the present form but to divide it in two parts. One of these parts concerns the mathematical aspects of Return Radius calculation and the rewritten article is already available arXiv:1201.4492 The second part will discuss the modelling of the Isotope Uptake and is still in preparation

Evgeny Lakshtanov; Leonid Lakshtanov

2011-05-07T23:59:59.000Z

395

DYNAMIC PHASORS IN MODELING, ANALYSIS AND CONTROL OF ENERGY  

E-Print Network (OSTI)

in: power electronics, electric drives and power systems. NEU Energy Processing Laboratory (1994) is a confluence of research and educational efforts: 1. Areas: power electronics, electric drives and power (ONR YIP) Systems Power Drives Electric Electronics Adaptive Converters Resonant Modeling Load

Stankoviæ, Aleksandar

396

Modelling the dynamical evolution of the Bootes dwarf spheroidal galaxy  

E-Print Network (OSTI)

We investigate a wide range of possible evolutionary histories for the recently discovered Bootes dwarf spheroidal galaxy, a Milky Way satellite. By means of N-body simulations we follow the evolution of possible progenitor galaxies of Bootes for a variety of orbits in the gravitational potential of the Milky Way. The progenitors considered cover the range from dark-matter-free star clusters to massive, dark-matter dominated outcomes of cosmological simulations. For each type of progenitor and orbit we compare the observable properties of the remnant after 10 Gyr with those of Bootes observed today. Our study suggests that the progenitor of Bootes must have been, and remains now, dark matter dominated. In general our models are unable to reproduce the observed high velocity dispersion in Bootes without dark matter. Our models do not support time-dependent tidal effects as a mechanism able to inflate significantly the internal velocity dispersion. As none of our initially spherical models is able to reproduce the elongation of Bootes, our results suggest that the progenitor of Bootes may have had some intrinsic flattening. Although the focus of the present paper is the Bootes dwarf spheroidal, these models may be of general relevance to understanding the structure, stability and dark matter content of all dwarf spheroidal galaxies.

M. Fellhauer; M. I. Wilkinson; N. W. Evans; V. Belokurov; M. J. Irwin; G. Gilmore; D. B. Zucker; J. T. Kleyna

2008-01-17T23:59:59.000Z

397

Static and Dynamic Debugging of Modelica Models Adrian Pop1  

E-Print Network (OSTI)

, Peter Fritzson1 , Francesco Casella2 1 Programming Environments Laboratory Department of Computer@elet.polimi.it Abstract The high abstraction level of equation-based object- oriented languages (EOO) such as Modelica has and algorithmic code debugging. Keywords: Modelica, Debugging, Modeling and Simulation, Transformations, Equations

Zhao, Yuxiao

398

Modeling the dynamics of tidally-interacting binary neutron stars up to merger  

E-Print Network (OSTI)

We propose an effective-one-body (EOB) model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to merger. Our EOB model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model dynamics (described by the gauge invariant relation between binding energy and orbital angular momentum), and the gravitational wave phasing, with new high-resolution multi-orbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement essentially within the uncertainty of the numerical data for all the configurations. Our model is the first semi-analytical model which captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

2014-12-15T23:59:59.000Z

399

Multiple higher-order singularities and iso-dynamics in a simple glass-former model  

E-Print Network (OSTI)

We investigate the slow dynamics of a colloidal model with two repulsive length scales, whose interaction potential is the sum of a hard-core and a square shoulder. Despite the simplicity of the interactions, Mode-Coupling theory predicts a complex dynamic scenario: a fluid-glass line with two reentrances and a glass-glass line ending with multiple higher-order ($A_3$ or $A_4$) singularities. In this work we verify the existence of the two $A_4$ points by numerical simulations, observing subdiffusive behaviour of the mean-square displacement and logarithmic decay of the density correlators. Surprisingly, we also discover a novel dynamic behaviour generated by the competition between the two higher-order singularities. This results in the presence of special loci along which the dynamics is identical \\textit{at all} length and time scales.

Nicoletta Gnan; Gayatri Das; Matthias Sperl; Francesco Sciortino; Emanuela Zaccarelli

2014-07-15T23:59:59.000Z

400

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Jeff Tappen; M.A. Wasiolek; D.W. Wu; J.F. Schmitt

2001-12-06T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Tappen, J. J.; Wasiolek, M. A.; Wu, D. W.; Schmitt, J. F.; Smith, A. J.

2002-02-26T23:59:59.000Z

402

Annual report, October 1980-September 1981 Multimedia radionuclide exposure assessment modeling.  

SciTech Connect

Pacific Northwest Laboratory (PNL) and Los Alamos National Laboratory (LANL) are jointly developing a methodology for assessing exposures of the air, water, and plants to radionuclides as part of an overall development effort of a radionuclide disposal site evaluation methodology. Work in FY-1981 continued the development of the Multimedia Contaminant Environmental Exposure Assessment (MCEA) methodology and initiated an assessment of radionuclide migration in Los Alamos and Pueblo Canyons, New Mexico, using the methodology. The AIRTRAN model was completed, briefly tested, and documented. In addition, a literature search for existing validation data for AIRTRAN was performed. The feasibility and advisability of including the UNSAT moisture flow model as a submodel of the terrestrial code BIOTRAN was assessed. A preliminary application of the proposed MCEA methodology, as it related to the Mortandad-South Mortandad Canyon site in New Mexico is discussed. This preliminary application represented a scaled-down version of the methodology in which only the terrestrial, overland, and surface water components were used. An update describing the progress in the assessment of radionuclide migration in Los Alamos and Pueblo Canyons is presented. 38 references, 47 figures, 11 tables.

Whelan, G.; Onishi, Y.; Simmons, C.S.; Horst, T.W.; Gupta, S.K.; Orgill, M.M.; Newbill, C.A.

1982-12-01T23:59:59.000Z

403

Dynamics  

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

Hydration Hydration Water on Rutile Studied by Backscattering Neutron Spectroscopy and Molecular Dynamics Simulation E. Mamontov,* ,† D. J. Wesolowski, ‡ L. Vlcek, § P. T. Cummings, §,| J. Rosenqvist, ‡ W. Wang, ⊥ and D. R. Cole ‡ Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6473, Chemical Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, Department of Chemical Engineering, Vanderbilt UniVersity, NashVille, Tennessee 37235-1604, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6496, and EnVironmental Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6036 ReceiVed: December 20, 2007; ReVised Manuscript ReceiVed: June 4, 2008 The high energy resolution, coupled with the wide dynamic range, of the new backscattering

404

Estimation of aerial deposition and foliar uptake of xenobiotics: Assessment of current models  

SciTech Connect

This report reviews existing mathematical and/or computer simulation models that estimate xenobiotic deposition to and transport through (both curricular and stomatal) vegetative surfaces. The report evaluates the potential for coupling the best of those models to the existing Uptake, Translocation, Accumulation, and Biodegradation model to be used for future xenobiotic exposure assessments. Here xenobiotic compounds are defined as airborne contaminants, both organic and gaseous pollutants, that are introduced into the environment by man. Specifically this document provides a detailed review of the state-of-the-art models that addressed aerial deposition of particles and gases to foliage; foliar and cuticular transport, metabolism, and uptake of organic xenobiotics; and stomatal transport of gaseous and volatile organic xenobiotic pollutants. Where detailed information was available, parameters for each model are provided on a chemical by chemical as well as species by species basis. Sufficient detail is provided on each model to assess the potential for adapting or coupling the model to the existing UTAB plant exposure model. 126 refs., 6 figs., 10 tabs.

Link, S.O.; Fellows, R.J.; Cataldo, D.A.; Droppo, J.G.; Van Voris, P.

1987-10-01T23:59:59.000Z

405

Application of a SeaWinds/QuikSCAT sea ice melt algorithm for assessing melt dynamics in the Canadian Arctic Archipelago  

E-Print Network (OSTI)

Application of a SeaWinds/QuikSCAT sea ice melt algorithm for assessing melt dynamics] A remotely sensed sea ice melt algorithm utilizing SeaWinds/QuikSCAT (QuikSCAT) data is developed and applied resolution radiometer Polar Pathfinder (APP-x) data set is used to identify spatially coupled relationships

406

An international land-biosphere model benchmarking activity for the IPCC Fifth Assessment Report (AR5)  

SciTech Connect

The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Project (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.

Hoffman, Forrest M [ORNL; Randerson, James T [ORNL; Thornton, Peter E [ORNL; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Erickson III, David J [ORNL; Fung, Inez [University of California, Berkeley

2009-12-01T23:59:59.000Z

407

Dynamics of strong-coupling models for cuprate superconductors: Exact results on finite lattices  

SciTech Connect

We discuss recent applications of exact numerical continued fraction expansion (CFE) techniques to calculate dynamical correlation functions of various strong-coupling models related to the high-temperature cuprate superconductors. For the two-dimensional square-lattice spin-1/2 Heisenberg antiferromagnet, we present exact results for the zero-temperature dynamical structure factor on finite-sized lattices and compare them to approximate results from a Schwinger boson mean-field theory, recently proposed by Arovas and Auerbach. We find that the mean-field theory represents a very good approximation to the exact spin excitation spectra and to the static spin correlations. We then investigation the dynamical spin-spin structure factor and the single-particle spectral function for finite model clusters with dopant induced hole-type charge carriers, in the strong-coupling limit of both the single-band Hubbard model (t-J-model) and the three-band Hubbard model (Kondo-Heisenberg model). Our results are consistent with the physical picture recently proposed by Zhang and Rice which implies an approximate mapping of the low-energy states in the three-band model onto an effective single-band theory. 33 refs., 4 figs.

Schuettler, H.B.; Chen, C.-X. (Georgia Univ., Athens, GA (USA). Center for Simulational Physics); Fedro, A.J. (Argonne National Lab., IL (USA) Northern Illinois Univ., Dekalb, IL (USA). Dept. of Physics)

1989-01-01T23:59:59.000Z

408

CB17: Inferring the dynamical history of a prestellar core with chemo-dynamical models  

E-Print Network (OSTI)

We present a detailed theoretical study of the isolated Bok globule CB17 (L1389) based on spectral maps of CS, HCO$^+$, C$^{18}$O, C$^{34}$S, and H$^{13}$CO$^+$ lines. A phenomenological model of prestellar core evolution, a time-dependent chemical model, and a radiative transfer simulation for molecular lines are combined to reconstruct the chemical and kinematical structure of this core. We developed a general criterion that allows to quantify the difference between observed and simulated spectral maps. By minimizing this difference, we find that very high and very low values of the effective sticking probability $S$ are not appropriate for the studied prestellar core. The most probable $S$ value for CB17 is 0.3--0.5. The spatial distribution of the intensities and self-absorption features of optically thick lines is indicative of UV irradiation of the core. By fitting simultaneously optically thin and optically thick transitions, we isolate the model that reproduces all the available spectral maps to a reasonable accuracy. The line asymmetry pattern in CB17 is reproduced by a combination of infall, rotation, and turbulent motions with velocities $\\sim0.05$ km s$^{-1}$, $\\sim0.1$ km s$^{-1}$, and $\\sim0.1$ km s$^{-1}$, respectively. These parameters corresponds to energy ratios $E_{\\rm rot}/E_{\\rm grav}\\approx0.03$, $E_{\\rm therm}/E_{\\rm grav}\\approx0.8$, and $E_{\\rm turb}/E_{\\rm grav}\\approx0.05$ (the rotation parameters are determined for $i=90^\\circ$). The chemical age of the core is about 2 Myrs. In particular, this is indicated by the central depletion of CO, CS, and HCO$^+$. Based on the angular momentum value, we argue that the core is going to fragment, i.e., to form a binary (multiple) star. (abridged)

Ya. Pavlyuchenkov; D. Wiebe; R. Launhardt; Th. Henning

2006-03-22T23:59:59.000Z

409

Detonating Failed Deflagration Model of Thermonuclear Supernovae I. Explosion Dynamics  

E-Print Network (OSTI)

We present a detonating failed deflagration model of Type Ia supernovae. In this model, the thermonuclear explosion of a massive white dwarf follows an off-center deflagration. We conduct a survey of asymmetric ignition configurations initiated at various distances from the stellar center. In all cases studied, we find that only a small amount of stellar fuel is consumed during deflagration phase, no explosion is obtained, and the released energy is mostly wasted on expanding the progenitor. Products of the failed deflagration quickly reach the stellar surface, polluting and strongly disturbing it. These disturbances eventually evolve into small and isolated shock-dominated regions which are rich in fuel. We consider these regions as seeds capable of forming self-sustained detonations that, ultimately, result in the thermonuclear supernova explosion. Preliminary nucleosynthesis results indicate the model supernova ejecta are typically composed of about 0.1-0.25 Msun of silicon group elements, 0.9-1.2 Msun of iron group elements, and are essentially carbon-free. The ejecta have a composite morphology, are chemically stratified, and display a modest amount of intrinsic asymmetry. The innermost layers are slightly egg-shaped with the axis ratio ~1.2-1.3 and dominated by the products of silicon burning. This central region is surrounded by a shell of silicon-group elements. The outermost layers of ejecta are highly inhomogeneous and contain products of incomplete oxygen burning with only small admixture of unburned stellar material. The explosion energies are ~1.3-1.5 10^51 erg.

Tomasz Plewa

2006-11-24T23:59:59.000Z

410

Research priorities in land use and land-cover change for the Earth system and integrated assessment modelling  

E-Print Network (OSTI)

). Copyright ? 2010 Royal Meteorological Society and Crown Copyright. KEY WORDS land use; land cover; Earth system models; integrated assessment models; research priorities Received 12 January 2009; Revised 9 March 2010; Accepted 14 March 2010 1. Introduction 1... biogeophysical, socio- economic and human decision-making perspectives. The Earth System Modeling (ESM) and the Integrated Assessment Modeling (IAM) communities play an impor- tant role in understanding and quantifying Earth system analysis and, specifically...

Hibbard, Kathy; Janetos, Anthony; van Vuuren, Detlef P.; Pongtatz, Julia; Rose, Steven K.; Betts, Richard; Herold, Martin; Feddema, Johannes J.

2010-01-01T23:59:59.000Z

411

IMA Journal of Applied Mathematics (2002) 67, 419439 Modelling thermal front dynamics in microwave heating  

E-Print Network (OSTI)

an electric field is applied to materials with high resistivity, the dipole moments of the molecules alignIMA Journal of Applied Mathematics (2002) 67, 419­439 Modelling thermal front dynamics in microwave July 2000; revised on 6 December 2001] The formation and propagation of thermal fronts in a cylindrical

Xin, Jack

412

Proper Orthogonal Decomposition-Based Modeling, Analysis, and Simulation of Dynamic Wind Load  

E-Print Network (OSTI)

Proper Orthogonal Decomposition-Based Modeling, Analysis, and Simulation of Dynamic Wind Load.1061/ ASCE 0733-9399 2005 131:4 325 CE Database subject headings: Simulation; Wind loads; Buildings; Random on the decomposition of the covariance and XPSD matrices is presented. A physically meaningful linkage between the wind

Chen, Xinzhong

413

Time Series Prediction by Chaotic Modeling of Nonlinear Dynamical Systems Arslan Basharat+  

E-Print Network (OSTI)

Inc. Clifton Park, NY, USA arslan.basharat@kitware.com Mubarak Shah+ + University of Central Florida Orlando, FL, USA shah@cs.ucf.edu Abstract We use concepts from chaos theory in order to model nonlinear dynamical systems that exhibit deterministic be- havior. Observed time series from such a system can be em

Central Florida, University of

414

Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits  

E-Print Network (OSTI)

. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control robots is still a challenge. For a given gait pattern, landing time and point of each leg are prescribed, i.e. they depend on parameters. The trajectory of each joint between lift-off and landing

Stryk, Oskar von

415

On the self-similarity assumption in dynamic models for large eddy simulations  

E-Print Network (OSTI)

that the present formulation of the DP is usually incompatible with its under- lying self-similarity assumption SSAOn the self-similarity assumption in dynamic models for large eddy simulations Daniele Carati eddy simulations and their underlying self-similarity assumption is discussed. The interpretation

Van Den Eijnden, Eric

416

Radiated seismic energy based on dynamic rupture models of faulting and Ralph J. Archuleta1  

E-Print Network (OSTI)

Radiated seismic energy based on dynamic rupture models of faulting Shuo Ma1 and Ralph J. Archuleta energy from three hypothetical crustal events, 30° dipping reverse fault, 60° dipping normal fault, and 0.34 MPa for the reverse, normal, and strike-slip faults, respectively. The energy distribution

Archuleta, Ralph

417

Modeling Malware Propagation in Networks of Smart Cell Phones with Spatial Dynamics  

E-Print Network (OSTI)

Modeling Malware Propagation in Networks of Smart Cell Phones with Spatial Dynamics Krishna and worm attacks tar- geted at cell phones have have bought to the forefront the seriousness of the security threat to this increasingly popular means of communication. The ability of smart cell phones

Sikdar, Biplab

418

Condensation of helium in aerogels and athermal dynamics of the Random Field Ising Model  

E-Print Network (OSTI)

Condensation of helium in aerogels and athermal dynamics of the Random Field Ising Model Geoffroy J isotherms of 4He in a silica aerogel be- come discontinuous below a critical temperature. We show by the aerogel structure, but to the disorder-driven critical point predicted for the athermal out

Boyer, Edmond

419

Modelling of pH dynamics in brain cells after stroke  

Science Journals Connector (OSTI)

...pH increases their production [21-23]. Ca2...responsible for the production and consumption of hydrogen ions and hence the...clinical practice. 2. Methods The pH dynamics model...metabolism including H+ production and consumption...

2011-01-01T23:59:59.000Z

420

EMULATING A GRAVITY MODEL TO INFER THE SPATIOTEMPORAL DYNAMICS OF AN INFECTIOUS DISEASE  

E-Print Network (OSTI)

EMULATING A GRAVITY MODEL TO INFER THE SPATIOTEMPORAL DYNAMICS OF AN INFECTIOUS DISEASE Roman grid. · Use pre-calculated matrices {Mtk}. GP-EMULATOR - BASED APPROACH · Based on constructing a new (proportions of zeros) on a pre-selected grid of parameters. · Second stage: We make inference based

Bjørnstad, Ottar Nordal

Note: This page contains sample records for the topic "dynamics models assessing" 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

Effects of Dynamic Forcing on Hillslope Water Balance Models , L.E. Band  

E-Print Network (OSTI)

simulations of the hillslope. In this work we focus specifically on closure relations for hillslope water]. Briefly stated, our objective in this work is to study the effect of system transience on hillslope waterEffects of Dynamic Forcing on Hillslope Water Balance Models C. E. Kees , L.E. Band , and M

422

Nonlinear dynamical systems with data and model uncertainties subjected to seismic loads  

E-Print Network (OSTI)

Nonlinear dynamical systems with data and model uncertainties subjected to seismic loads Christophe loads with data uncertainties for the nonlinearities. An application to a multisupported reactor coolant and Acoustics Dpt., 92141, Clamart cedex, France ABSTRACT This paper deals with data uncertainties

Paris-Sud XI, Université de

423

Modeling of impact dynamics of tennis ball with a flat surface  

E-Print Network (OSTI)

A two-mass model with a spring and a damper in the vertical direction, accounting for vertical translational motion and a torsional spring and a damper connecting the rotational motion of two masses is used to simulate the dynamics of a tennis ball...

Jafri, Syed M.

2005-08-29T23:59:59.000Z

424

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics  

E-Print Network (OSTI)

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics problems, particularly for high-speed Surface Effect Ships (SES) such as the recently proposed Harley FastShip and/or a surface-piercing body (ship), within the framework of potential flow theory. The three

Grilli, Stéphan T.

425

DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT  

E-Print Network (OSTI)

1 DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT CHAMOUN MARWAN to improve industrial energy efficiency, the development of a high temperature heat pump using water vapor as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump

Paris-Sud XI, Université de

426

Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua)  

E-Print Network (OSTI)

uniformity) to variations in input parameters (such as radio-frequency (rf) power, flow rate, dc bias, and energy balance equations inside a high-frequency, high-intensity electric field. Realistic simulation91 Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua

Nikolaou, Michael

427

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows  

E-Print Network (OSTI)

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows K Magnetic fields a b s t r a c t The ice giant planets, Uranus and Neptune, have magnetic fields to yield small-scale and disorganized turbulence. In agreement with ice giant observations, both

428

Global dynamics of a vector disease model with saturation incidence and time delay  

Science Journals Connector (OSTI)

......Journal of Applied Mathematics (2011) 76, 919-937 doi:10.1093/imamat/hxr013 Advance Access publication on March 17, 2011 Global dynamics of a vector disease model with saturation incidence and time delay RUI XU Institute of Applied Mathematics......

Rui Xu; Zhien Ma

2011-12-01T23:59:59.000Z

429

Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds  

E-Print Network (OSTI)

85 Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds Stephen T controls on supply and transport of sediment and wood in a small (approximately two square kilometers) basin in the Oregon Coast Range, typical of streams at the interface between episodic sediment and wood

430

Simplified dynamic models for control of riser slugging in offshore oil production  

E-Print Network (OSTI)

ForReview Only Simplified dynamic models for control of riser slugging in offshore oil production, Department of Chemical Engineering Keywords: oil production, two-phase flow, severe slugging, riser slugging for control of riser slugging in offshore oil production Esmaeil Jahanshahi, Sigurd Skogestad Department

Skogestad, Sigurd

431

Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink Arenas  

E-Print Network (OSTI)

1 Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink, USA, Fax: 617-432-4122, Abstract Many ice rink arenas have ice resurfacing equipment that uses fossil temperature distributions in ice rinks. The numerical results agree reasonably with the corresponding

Chen, Qingyan "Yan"

432

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS  

E-Print Network (OSTI)

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS by Chang Liu B) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) February 2010 © Chang Liu, 2010 #12;ii Abstract Nanoscale beam of nanoscale beams. The objective is to provide NEMS designers with an efficient set of tools that can predict

Phani, A. Srikantha

433

A simplified model of thin layer static/flowing dynamics for granular materials with yield  

E-Print Network (OSTI)

/deposition processes when a layer of particles is flowing over a static layer or near the destabilization and arrestA simplified model of thin layer static/flowing dynamics for granular materials with yield, 75005 Paris, France, 4 ANGE team, INRIA, CETMEF, Lab. J.-L. Lions, Paris, France Abstract We introduce

Paris-Sud XI, Université de

434

Modeling aspects of the ecological and evolutionary dynamics of the endangered Houston toad  

E-Print Network (OSTI)

-recapture techniques to estimate survivorship, and simulation modeling to explore the impacts of the difference in age at first reproduction and to project the future dynamics of the population at the GLR. From 2001 – 2005, 225 individual Houston toads (199 M : 26 F...

Swannack, Todd Michael

2009-05-15T23:59:59.000Z

435

Modeling the Dynamics of Desakota Regions: Global - Local Nexus in the Taipei Metropolitan Area  

E-Print Network (OSTI)

develops a GIS-based CA framework based on the desakota model to not only simulate the unique urbanization processes in Asia but also integrate the influence of globalization into Asian urban dynamics. Three approaches are developed in the CA simulation: 1...

Wu, Bing-Sheng

2010-10-12T23:59:59.000Z

436

Ecological Modelling 180 (2004) 135151 Simulating forest fuel and fire risk dynamics across  

E-Print Network (OSTI)

fuel module tracks fine fuel, coarse fuel and live fuel for each cell on a landscape. Fine fuel age (the oldest age cohorts) in combination with disturbance history. Live fuels, also called canopyEcological Modelling 180 (2004) 135­151 Simulating forest fuel and fire risk dynamics across

He, Hong S.

437

Simulation of ultrafast heating induced structural dynamics using a one-dimensional spring model  

Science Journals Connector (OSTI)

We developed a one-dimensional spring model to study the dynamics of lattice motion upon ultrafast laser heating. Using this model, we simulated atomic positions as a function of time in a free-standing thin monoatomic metal film as well as in a thin film on a substrate. In particular, we studied how the electronic thermal stress influences lattice expansion after the ultrafast laser heating. The simulation results agree very well with experimental data obtained with femtosecond electron diffraction.

Junjie Li; Rick Clinite; Xuan Wang; Jianming Cao

2009-07-22T23:59:59.000Z

438

Stochastic Dynamic Demand Inventory Models with Explicit Transportation Costs and Decisions  

E-Print Network (OSTI)

is the policy where several small loads will be dispatched as a single, combined load. From an inventory-modeling perspec- tive, the integrated inventory-transportation problems add dispatch quantities as decision variables to the stochastic dynamic inventory...): The vendor makes the inventory replen- ishment decisions on how much to order from the outside supplier. 2. Pure Outbound Transportation Models (PO): The collection depot makes the delivery schedules of order dispatches to the buyer(s). 3. Integrated...

Zhang, Liqing

2011-07-01T23:59:59.000Z

439

Computational fluid dynamics combustion modelling--A comparison of secondary air system designs  

SciTech Connect

A newly developed computer simulation of the combustion process in a kraft recovery furnace uses computational fluid dynamics to model the processes of mass, momentum, and energy transport. This paper describes two models and a presentation of the flow fields obtained. The results predict a dramatic improvement in combustion behavior using a refined secondary air system with reduction in particulate carryover, enhanced operating temperatures, more uniform gas flow, and less carbon monoxide at the furnace exit.

Jones, A.K. (ABB Combustion Engineering Systems, Ottawa, Ontario (Canada)); Chapman, P.J. (ABB Combustion Engineering Systems, Windsor, CT (United States))

1993-07-01T23:59:59.000Z

440

On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry  

E-Print Network (OSTI)

On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry Effective, economic extraction of ocean wave energy requires an intimate under- standing of the ocean wave

Victoria, University of

Note: This page contains sample records for the topic "dynamics models assessing" 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

Simulation of polar stratospheric clouds in the specified dynamics version of the whole atmosphere community climate model  

E-Print Network (OSTI)

We evaluate the simulation of polar stratospheric clouds (PSCs) in the Specified Dynamics version of the Whole Atmosphere Community Climate Model for the Antarctic winter 2005. In this model, PSCs are assumed to form ...

Wegner, T.

442

Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model  

E-Print Network (OSTI)

with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

Schuh, Harald

443

Quantum Quenches and Off-Equilibrium Dynamical Transition in the Infinite-Dimensional Bose-Hubbard Model  

SciTech Connect

We study the off-equilibrium dynamics of the infinite-dimensional Bose-Hubbard model after a quantum quench. The dynamics can be analyzed exactly by mapping it to an effective Newtonian evolution. For integer filling, we find a dynamical transition separating regimes of small and large quantum quenches starting from the superfluid state. This transition is very similar to the one found for the fermionic Hubbard model by mean field approximations.

Sciolla, Bruno; Biroli, Giulio [Institut de Physique Theorique, CEA/DSM/IPhT-CNRS/URA 2306 CEA-Saclay, F-91191 Gif-sur-Yvette (France)

2010-11-26T23:59:59.000Z

444

Discrete Fracture Network Models for Risk Assessment of Carbon Sequestration in Coal  

SciTech Connect

A software package called DFNModeler has been developed to assess the potential risks associated with carbon sequestration in coal. Natural fractures provide the principal conduits for fluid flow in coal-bearing strata, and these fractures present the most tangible risks for the leakage of injected carbon dioxide. The objectives of this study were to develop discrete fracture network (DFN) modeling tools for risk assessment and to use these tools to assess risks in the Black Warrior Basin of Alabama, where coal-bearing strata have high potential for carbon sequestration and enhanced coalbed methane recovery. DFNModeler provides a user-friendly interface for the construction, visualization, and analysis of DFN models. DFNModeler employs an OpenGL graphics engine that enables real-time manipulation of DFN models. Analytical capabilities in DFNModeler include display of structural and hydrologic parameters, compartmentalization analysis, and fluid pathways analysis. DFN models can be exported to third-party software packages for flow modeling. DFN models were constructed to simulate fracturing in coal-bearing strata of the upper Pottsville Formation in the Black Warrior Basin. Outcrops and wireline cores were used to characterize fracture systems, which include joint systems, cleat systems, and fault-related shear fractures. DFN models were constructed to simulate jointing, cleating, faulting, and hydraulic fracturing. Analysis of DFN models indicates that strata-bound jointing compartmentalizes the Pottsville hydrologic system and helps protect shallow aquifers from injection operations at reservoir depth. Analysis of fault zones, however, suggests that faulting can facilitate cross-formational flow. For this reason, faults should be avoided when siting injection wells. DFN-based flow models constructed in TOUGH2 indicate that fracture aperture and connectivity are critical variables affecting the leakage of injected CO{sub 2} from coal. Highly transmissive joints near an injection well have potential to divert a large percentage of an injected CO{sub 2} stream away from a target coal seam. However, the strata-bound nature of Pottsville fracture systems is a natural factor that mitigates the risk of long-range leakage and surface seepage. Flow models indicate that cross-formational flow in strata-bound joint networks is low and is dissipated by about an order of magnitude at each successive bedding contact. These models help confirm that strata-bound joint networks are self-compartmentalizing and that the thick successions of interbedded shale and sandstone separating the Pottsville coal zones are confining units that protect shallow aquifers from injection operations at reservoir depth. DFN models are powerful tools for the simulation and analysis of fracture networks and can play an important role in the assessment of risks associated with carbon sequestration and enhanced coalbed methane recovery. Importantly, the stochastic nature DFN models dictates that they cannot be used to precisely reproduce reservoir conditions in a specific field area. Rather, these models are most useful for simulating the fundamental geometric and statistical properties of fracture networks. Because the specifics of fracture architecture in a given area can be uncertain, multiple realizations of DFN models and DFN-based flow models can help define variability that may be encountered during field operations. Using this type of approach, modelers can inform the risk assessment process by characterizing the types and variability of fracture architecture that may exist in geologic carbon sinks containing natural fractures.

Jack Pashin; Guohai Jin; Chunmiao Zheng; Song Chen; Marcella McIntyre

2008-07-01T23:59:59.000Z

445

Dynamic electro-thermal modeling of all-vanadium redox flow battery with forced cooling strategies  

Science Journals Connector (OSTI)

Abstract The present study focuses on the dynamic electro-thermal modeling for the all-vanadium redox flow battery (VRB) with forced cooling strategies. The Foster network is adopted to dynamically model the heat dissipation of VRB with heat exchangers. The parameters of Foster network are extracted by fitting the step response of it to the results of linearized CFD model. Then a complete electro-thermal model is proposed by coupling the heat generation model, Foster network and electrical model. Results show that the established model has nearly the same accuracy with the nonlinear CFD model in electrolyte temperature prediction but drastically improves the computational efficiency. The modeled terminal voltage is also benchmarked with the experimental data under different current densities. The electrolyte temperature is found to be significantly influenced by the flow rate of coolant. As compared, although the electrolyte flow rate has unremarkable impact on electrolyte temperature, its effect on system pressure drop and battery efficiency is significant. Increasing the electrolyte flow rate improves the coulombic efficiency, voltage efficiency and energy efficiency simultaneously but at the expense of higher pump power demanded. An optimal flow rate exists for each operating condition to maximize the system efficiency.

Zhongbao Wei; Jiyun Zhao; Binyu Xiong

2014-01-01T23:59:59.000Z

446

Fault detection and isolation of a dual spool gas turbine engine using dynamic neural networks and multiple model approach  

Science Journals Connector (OSTI)

In this paper, a fault detection and isolation (FDI) scheme for an aircraft jet engine is developed. The proposed FDI system is based on the multiple model approach and utilizes dynamic neural networks (DNNs) to accomplish this goal. Towards this end, ... Keywords: Bank of detection and isolation filters, Dual spool gas turbine engine, Dynamic neural networks, Fault diagnosis, Multiple model scheme

Z. N. Sadough Vanini; K. Khorasani; N. Meskin

2014-02-01T23:59:59.000Z

447

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai, Dongmei Chen, Tess J. Moon  

E-Print Network (OSTI)

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai to improve the performance of a PEM fuel cell Simulation Results Advanced Power Systems and Controls (GDL) to reduce water saturation · Model water transport in PEM fuel cell Contribution: · Dynamic

Ben-Yakar, Adela

448

Technical Review of the CENWP Computational Fluid Dynamics Model of the John Day Dam Forebay  

SciTech Connect

The US Army Corps of Engineers Portland District (CENWP) has developed a computational fluid dynamics (CFD) model of the John Day forebay on the Columbia River to aid in the development and design of alternatives to improve juvenile salmon passage at the John Day Project. At the request of CENWP, Pacific Northwest National Laboratory (PNNL) Hydrology Group has conducted a technical review of CENWP's CFD model run in CFD solver software, STAR-CD. PNNL has extensive experience developing and applying 3D CFD models run in STAR-CD for Columbia River hydroelectric projects. The John Day forebay model developed by CENWP is adequately configured and validated. The model is ready for use simulating forebay hydraulics for structural and operational alternatives. The approach and method are sound, however CENWP has identified some improvements that need to be made for future models and for modifications to this existing model.

Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.

2010-12-01T23:59:59.000Z

449

RAVEN AS A TOOL FOR DYNAMIC PROBABILISTIC RISK ASSESSMENT: SOFTWARE OVERVIEW  

SciTech Connect

RAVEN is a software tool under development at the Idaho National Laboratory (INL) that acts as the control logic driver and post-processing tool for the newly developed Thermo-Hydraylic code RELAP- 7. The scope of this paper is to show the software structure of RAVEN and its utilization in connection with RELAP-7. A short overview of the mathematical framework behind the code is presented along with its main capabilities such as on-line controlling/monitoring and Monte-Carlo sampling. A demo of a Station Black Out PRA analysis of a simplified Pressurized Water Reactor (PWR) model is shown in order to demonstrate the Monte-Carlo and clustering capabilities.

Alfonsi Andrea; Mandelli Diego; Rabiti Cristian; Joshua Cogliati; Robert Kinoshita

2013-05-01T23:59:59.000Z

450

DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS  

SciTech Connect

In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do not exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in which flow regime transition occurs.

X. Wang; X. Sun; H. Zhao

2011-09-01T23:59:59.000Z

451

Fuzzy integrated vulnerability assessment model for critical facilities in combating the terrorism  

Science Journals Connector (OSTI)

Critical facility vulnerability assessment is a highly complex strategic activity in combating the terrorism and necessitates a structured quantified methodology to support the decision-making process in defense planning. In the system perspective, the critical facility, such as airport, dam, governmental facility, harbor, nuclear power plant, oil plant etc., can be defined as a system that relies on a group of different interdependent logical and physical entities as system functions and system components. The aim of this paper is to present a realistic approach to determine the vulnerability of such a system defended against the terrorist attack under multiple criteria which can be both qualitative and quantitative by considering these interdependencies. The proposed approach, called fuzzy integrated vulnerability assessment model (FIVAM), is based on fuzzy set theory, Simple Multi-Attribute Rating Technique (SMART) and Fuzzy Cognitive Maps (FCM) methodology in a group decision-making environment. The FIVAM approach is presented step-by-step and applied to a simple case study on airport vulnerability assessment. The results of the application are compared to those observed through a classical vulnerability assessment model to illustrate the effectiveness of the FIVAM. Furthermore, FIVAM provides a framework to identify the hidden vulnerabilities caused by the functional interdependencies within the system. The results also show that FIVAM quantifies the vulnerability of the system, system functions and system components, and determines the most critical functions and components by simulating the system behavior.

Ilker Akgun; Ahmet Kandakoglu; Ahmet Fahri Ozok

2010-01-01T23:59:59.000Z

452

Modelling risk and risking models: the diffusive boundary between science and policy in volcanic risk assessment  

E-Print Network (OSTI)

to the appreciation that the eruptions may continue for 282 decades and should be regarded as a “chronic” problem for planning purposes (Donovan and 283 Oppenheimer, 2014). Managing this transition has required consistent yet innovative 284 approaches to scientific... to their advice. 524 There is abundant evidence of the political challenges of risk assessment and management on 525 Montserrat, and the complex boundaries and connectivities involved (Aspinall et al., 2002; 526 Haynes et al., 2007; Donovan and Oppenheimer...

Donovan, Amy R.; Oppenheimer, Clive

2014-11-27T23:59:59.000Z

453

Standardised and transparent model descriptions for agent-based models: Current status and prospects  

Science Journals Connector (OSTI)

Agent-based models are helpful to investigate complex dynamics in coupled human-natural systems. However, model assessment, model comparison and replication are hampered to a large extent by a lack of transparency and comprehensibility in model descriptions. ... Keywords: Agent-based modelling, Domain specific languages, Graphical representations, Model communication, Model comparison, Model design, Model development, Model replication, Standardised protocols

Birgit Müller, Stefano Balbi, Carsten M. Buchmann, Luís De Sousa, Gunnar Dressler, Jürgen Groeneveld, Christian J. Klassert, Quang Bao Le, James D. A. Millington, Henning Nolzen, Dawn C. Parker, J. Gary Polhill, Maja Schlüter, Jule Schulze, Nina Schwarz, Zhanli Sun, Patrick Taillandier, Hanna Weise

2014-05-01T23:59:59.000Z

454

Short-time dynamics of Fe{sub 2}/V{sub 13} magnetic superlattice models  

SciTech Connect

Critical relaxation from a low-temperature fully ordered state of Fe{sub 2}/V{sub 13} iron-vanadium magnetic superlattice models has been studied using the method of short-time dynamics. Systems with three variants of the ratio R of inter-to intralayer exchange coupling have been considered. Particles with N = 262144 spins have been simulated with periodic boundary conditions. Calculations have been performed using the standard Metropolis algorithm of the Monte Carlo method. The static critical exponents of magnetization and correlation radius, as well as the dynamic critical exponent, have been calculated for three R values. It is established that a small decrease in the exchange ratio (from R = 1.0 to 0.8) does not significantly influence the character of the short-time dynamics in the models studied. A further significant decrease in this ratio (to R = 0.01), for which a transition from three-dimensional to quasi-two-dimensional magnetism is possible, leads to significant changes in the dynamic behavior of iron-vanadium magnetic superlattice models.

Murtazaev, A. K.; Mutailamov, V. A., E-mail: vadim.mut@mail.ru [Russian Academy of Sciences, Amirkhanov Institute of Physics, Daghestan Scientific Center (Russian Federation)

2013-04-15T23:59:59.000Z

455

Dispersion models and air quality data for population exposure assessment to air pollution  

Science Journals Connector (OSTI)

Evaluating the extent of exposure to chemicals in absence of continuous measurements of their concentration in air and direct measures of personal exposure is crucial for epidemiological studies. Dispersion models can be a useful tool for reproducing spatio-temporal distribution of contaminants emitted by a specific source. However, they cannot easily be applied to short-term epidemiological studies because they require precise information on daily emission scenarios for a long time, which are generally not available. The aim of this study was to better assess the exposure in the industrial area of Brindisi, which suffers from various critical epidemiological situations, by integrating air pollution concentration data, emissions and model simulations concerning a specific point source. The results suggest that in the absence of direct exposure data and detailed information on specific pollutants associated to an emission, population exposure may be better assessed by taking into account proxy pollutants and the wind (direction and speed) as a potential health effects modifier.

Cristina Mangia; Marco Cervino; Emilio Antonio Luca Gianicolo

2014-01-01T23:59:59.000Z

456

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates  

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

Earthquake simulations help scientists understand the hazards posed by Earthquake simulations help scientists understand the hazards posed by future earthquakes. Earthquake computational models are validated by simulating well-recorded historical earthquakes and comparing simulation results to observational data. The purple border shows the extent of the 3-D structural model in the 3-D inversion. Events in red, with stations in blue. En-Jui Lee, University of Wyoming Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI Name: Thomas Jordan PI Email: tjordan@usc.edu Institution: USC Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Earth Science Researchers will use Southern California Earthquake Center (SCEC) dynamic rupture simulation software to investigate high-frequency seismic energy

457

Dynamic modeling and optimal control strategy of waste heat recovery Organic Rankine Cycles  

Science Journals Connector (OSTI)

Organic Rankine Cycles (ORCs) are particularly suitable for recovering energy from low-grade heat sources. This paper describes the behavior of a small-scale ORC used to recover energy from a variable flow rate and temperature waste heat source. A traditional static model is unable to predict transient behavior in a cycle with a varying thermal source, whereas this capability is essential for simulating an appropriate cycle control strategy during part-load operation and start and stop procedures. A dynamic model of the ORC is therefore proposed focusing specifically on the time-varying performance of the heat exchangers, the dynamics of the other components being of minor importance. Three different control strategies are proposed and compared. The simulation results show that a model predictive control strategy based on the steady-state optimization of the cycle under various conditions is the one showing the best results.

Sylvain Quoilin; Richard Aumann; Andreas Grill; Andreas Schuster; Vincent Lemort; Hartmut Spliethoff

2011-01-01T23:59:59.000Z

458

Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts.  

SciTech Connect

directly, rather than through simplified abstractions. It also a llows for complex representations of the source term, e.g., the explicit representation of many individual waste packages (i.e., meter - scale detail of an entire waste emplacement drift). This report fulfills the Generic Disposal System Analysis Work Packa ge Level 3 Milestone - Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts (M 3 FT - 1 4 SN08080 3 2 ).

Sevougian, S. David; Freeze, Geoffrey A. [Sandia National Laboratories, Albuquerque, NM; Gardner, William Payton [Sandia National Laboratories, Albuquerque, NM; Hammond, Glenn Edward [Sandia National Laboratories, Albuquerque, NM; Mariner, Paul [Sandia National Laboratories, Albuquerque, NM

2014-09-01T23:59:59.000Z

459

An application of probabilistic safety assessment methods to model aircraft systems and accidents  

SciTech Connect

A case study modeling the thrust reverser system (TRS) in the context of the fatal accident of a Boeing 767 is presented to illustrate the application of Probabilistic Safety Assessment methods. A simplified risk model consisting of an event tree with supporting fault trees was developed to represent the progression of the accident, taking into account the interaction between the TRS and the operating crew during the accident, and the findings of the accident investigation. A feasible sequence of events leading to the fatal accident was identified. Several insights about the TRS and the accident were obtained by applying PSA methods. Changes proposed for the TRS also are discussed.

Martinez-Guridi, G.; Hall, R.E.; Fullwood, R.R.

1998-08-01T23:59:59.000Z

460

Dynamic customisation, validation and integration of product data models using semantic web tools  

Science Journals Connector (OSTI)

Standard product data models enable information exchange across different organisations, actors, processes and stages in the product lifecycle. These standard models need to support diverse domain-specific requirements from the multitude of disciplines involved during a product's lifecycle. Due to this diversity, challenges are to: 1) develop multidisciplinary models; 2) extend them to support new requirements over time; 3) implement the resulting gigantic information models. ISO 10303, the reference standard for PLM-related data models provides mechanisms to enable specialisation of generic product data to address some of these challenges. In this paper, we introduce the need for dynamic product data models, detail the ISO method and identify its limitations. We present enhancements to that methodology using ontologies and the SPARQL Inference Notation (SPIN) for validating product data. To conclude, we show how these ontologies can be leveraged to ease and strengthen PLM data integration through the use of Linked Data.

Sylvere Krima; Allison Barnard Feeney; Sebti Foufou

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics models assessing" 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

A finite-patch model of a flexible plate via Kane's dynamics  

Science Journals Connector (OSTI)

Military hardware must undergo extensive shock-response analysis to predict survivability to mechanical shock. Although finite element modelling is commonly used to model such hardware, alternative methods which offer the possibility of shorter modelling, modification, or simulation times continue to be desirable. This research effort applies Kane's dynamics to the problem of plate modelling, toward shock-response analysis of homogeneous plates having various geometries and boundary conditions. Analytical equations of motion are found for a continuous flexible plate that is discretised in checkerboard fashion as a patchwork of rigid rectangular patches connected by flexible springs and damped modally. A MATLAB implementation is used to validate the model against pertinent analytical and numerical benchmark analyses, for a variety of boundary conditions. The model is then reduced by applying non-holonomic constraints directly using Kane's method, and revalidated via MATLAB for a rectangular plate in simple support.

R. David Hampton

2012-01-01T23:59:59.000Z

462

Modeling the Gila-San Francisco Basin using system dynamics in support of the 2004 Arizona Water Settlement Act.  

SciTech Connect

Water resource management requires collaborative solutions that cross institutional and political boundaries. This work describes the development and use of a computer-based tool for assessing the impact of additional water allocation from the Gila River and the San Francisco River prescribed in the 2004 Arizona Water Settlements Act. Between 2005 and 2010, Sandia National Laboratories engaged concerned citizens, local water stakeholders, and key federal and state agencies to collaboratively create the Gila-San Francisco Decision Support Tool. Based on principles of system dynamics, the tool is founded on a hydrologic balance of surface water, groundwater, and their associated coupling between water resources and demands. The tool is fitted with a user interface to facilitate sensitivity studies of various water supply and demand scenarios. The model also projects the consumptive use of water in the region as well as the potential CUFA (Consumptive Use and Forbearance Agreement which stipulates when and where Arizona Water Settlements Act diversions can be made) diversion over a 26-year horizon. Scenarios are selected to enhance our understanding of the potential human impacts on the rivers ecological health in New Mexico; in particular, different case studies thematic to water conservation, water rights, and minimum flow are tested using the model. The impact on potential CUFA diversions, agricultural consumptive use, and surface water availability are assessed relative to the changes imposed in the scenarios. While it has been difficult to gage the acceptance level from the stakeholders, the technical information that the model provides are valuable for facilitating dialogues in the context of the new settlement.

Tidwell, Vincent Carroll; Sun, Amy Cha-Tien; Peplinski, William J.; Klise, Geoffrey Taylor

2012-04-01T23:59:59.000Z

463

Development of Simplified Probabilistic Risk Assessment Model for Seismic Initiating Event  

SciTech Connect

ABSTRACT This paper discusses a simplified method to evaluate seismic risk using a methodology built on dividing the seismic intensity spectrum into multiple discrete bins. The seismic probabilistic risk assessment model uses Nuclear Regulatory Commission’s (NRC’s) full power Standardized Plant Analysis Risk (SPAR) model as the starting point for development. The seismic PRA models are integrated with their respective internal events at-power SPAR model. This is accomplished by combining the modified system fault trees from the full power SPAR model with seismic event tree logic. The peak ground acceleration is divided into five bins. The g-value for each bin is estimated using the geometric mean of lower and upper values of that particular bin and the associated frequency for each bin is estimated by taking the difference between upper and lower values of that bin. The component’s fragilities are calculated for each bin using the plant data, if available, or generic values of median peak ground acceleration and uncertainty values for the components. For human reliability analysis (HRA), the SPAR HRA (SPAR-H) method is used which requires the analysts to complete relatively straight forward worksheets that include the performance shaping factors (PSFs). The results are then used to estimate human error probabilities (HEPs) of interest. This work is expected to improve the NRC’s ability to include seismic hazards in risk assessments for operational events in support of the reactor oversight program (e.g., significance determination process).

S. Khericha; R. Buell; S. Sancaktar; M. Gonzalez; F. Ferrante

2012-06-01T23:59:59.000Z

464

Renormalization of lattice-regularized quantum gravity models II. The case of causal dynamical triangulations  

E-Print Network (OSTI)

The causal dynamical triangulations approach aims to construct a quantum theory of gravity as the continuum limit of a lattice-regularized model of dynamical geometry. A renormalization group scheme--in concert with finite size scaling analysis--is essential to this aim. Formulating and implementing such a scheme in the present context raises novel and notable conceptual and technical problems. I explored these problems, and, building on standard techniques, suggested potential solutions in the first paper of this two-part series. As an application of these solutions, I now propose a renormalization group scheme for causal dynamical triangulations. This scheme differs significantly from that studied recently by Ambjorn, Gorlich, Jurkiewicz, Kreienbuehl, and Loll.

Joshua H. Cooperman

2014-06-17T23:59:59.000Z

465

Introduction to the application of the dynamical systems theory in the study of the dynamics of cosmological models of dark energy  

E-Print Network (OSTI)

The theory of the dynamical systems is a very complex subject which has brought several surprises in the recent past in connection with the theory of chaos and fractals. The application of the tools of the dynamical systems in cosmological settings is less known in spite of the amount of published scientific papers on this subject. In this paper a -- mostly pedagogical -- introduction to the application in cosmology of the basic tools of the dynamical systems theory is presented. It is shown that, in spite of their amazing simplicity, these allow to extract essential information on the asymptotic dynamics of a wide variety of cosmological models. The power of these tools is illustrated within the context of the so called $\\Lambda$CDM and scalar field models of dark energy. This paper is suitable for teachers, undergraduate and postgraduate students from physics and mathematics disciplines.

García-Salcedo, Ricardo; Horta-Rangel, Francisco A; Quiros, Israel; Sanchez-Guzmán, Daniel

2015-01-01T23:59:59.000Z

466

Helicon thruster plasma modeling: Two-dimensional fluid-dynamics and propulsive performances  

SciTech Connect

An axisymmetric macroscopic model of the magnetized plasma flow inside the helicon thruster chamber is derived, assuming that the power absorbed from the helicon antenna emission is known. Ionization, confinement, subsonic flows, and production efficiency are discussed in terms of design and operation parameters. Analytical solutions and simple scaling laws for ideal plasma conditions are obtained. The chamber model is then matched with a model of the external magnetic nozzle in order to characterize the whole plasma flow and assess thruster performances. Thermal, electric, and magnetic contributions to thrust are evaluated. The energy balance provides the power conversion between ions and electrons in chamber and nozzle, and the power distribution among beam power, ionization losses, and wall losses. Thruster efficiency is assessed, and the main causes of inefficiency are identified. The thermodynamic behavior of the collisionless electron population in the nozzle is acknowledged to be poorly known and crucial for a complete plasma expansion and good thrust efficiency.

Ahedo, Eduardo; Navarro-Cavalle, Jaume [ETS Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)

2013-04-15T23:59:59.000Z

467

Control method and system for hydraulic machines employing a dynamic joint motion model  

DOE Patents (OSTI)

A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

Danko, George (Reno, NV)

2011-11-22T23:59:59.000Z

468

Assessment of Food Chain Pathway Parameters in Biosphere Models: Annual Progress Report for Fiscal Year 2004  

SciTech Connect

This Annual Progress Report describes the work performed and summarizes some of the key observations to date on the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report describes activities undertaken to collect samples of soils from three regions of the United States, the Southeast, Northwest, and Southwest, and perform analyses to characterize their physical and chemical properties. Section 3 summarizes information gathered regarding agricultural practices and common and unusual crops grown in each of these three areas. Section 4 describes progress in studying radionuclide uptake in several representative crops from the three soil types in controlled laboratory conditions. Section 5 describes a range of international coordination activities undertaken by Project staff in order to support the underlying data needs of the Project. Section 6 provides a very brief summary of the status of the GENII Version 2 computer program, which is a “client” of the types of data being generated by the Project, and for which the Project will be providing training to the US NRC staff in the coming Fiscal Year. Several appendices provide additional supporting information.

Napier, Bruce A.; Krupka, Kenneth M.; Fellows, Robert J.; Cataldo, Dominic A.; Valenta, Michelle M.; Gilmore, Tyler J.

2004-12-02T23:59:59.000Z

469

Modeling gas and brine migration for assessing compliance of the Waste Isolation Pilot Plant  

SciTech Connect

At the request of the WIPP Project Integration Office (WPIO) of the DOE, the WIPP Performance Assessment (PA) Department of Sandia National Laboratories (SNL) has completed preliminary uncertainty and sensitivity analyses of gas and brine migration away from the undisturbed repository. This paper contains descriptions of the numerical model and simulations, including model geometries and parameter values, and a summary of major conclusions from sensitivity analyses. Because significant transport of contaminants can only occur in a fluid (gas or brine) medium, two-phase flow modeling can provide an estimate of the distance to which contaminants can migrate. Migration of gas or brine beyond the RCRA ``disposal-unit boundary`` or the Standard`s accessible environment constitutes a potential, but not certain, violation and may require additional evaluations of contaminant concentrations.

Vaughn, P. [Applied Physics, Inc., Albuquerque, NM (United States); Butcher, B. [Sandia National Labs., Albuquerque, NM (United States); Helton, J. [Arizona State Univ., Tempe, AZ (United States); Swift, P. [Tech. Reps., Inc., Albuquerque, NM (United States)

1993-10-01T23:59:59.000Z

470

Generalized spherically symmetric gravitational model: Hamiltonian dynamics in extended phase space and BRST charge  

E-Print Network (OSTI)

We construct Hamiltonian dynamics of the generalized spherically symmetric gravitational model in extended phase space. We start from the Faddeev - Popov effective action with gauge-fixing and ghost terms, making use of gauge conditions in differential form. It enables us to introduce missing velocities into the Lagrangian and then construct a Hamiltonian function according a usual rule which is applied for systems without constraints. The main feature of Hamiltonian dynamics in extended phase space is that it can be proved to be completely equivalent to Lagrangian dynamics derived from the effective action. We find a BRST invariant form of the effective action by adding terms not affecting Lagrangian equations. After all, we construct the BRST charge according to the Noether theorem. Our algorithm differs from that by Batalin, Fradkin and Vilkovisky, but the resulting BRST charge generates correct transformations for all gravitational degrees of freedom including gauge ones. Generalized spherically symmetric model imitates the full gravitational theory much better then models with finite number of degrees of freedom, so that one can expect appropriate results in the case of the full theory.

T. P. Shestakova

2014-06-12T23:59:59.000Z

471

Detuning Induced Effects: Symmetry-Breaking Bifurcations in Dynamic Model of One-Mode Laser  

E-Print Network (OSTI)

The concept of broken symmetry is used to study bifurcations of equilibria and dynamical instabilities in dynamic model of one-mode laser (nonresonant complex Lorenz model) on the basis of modified Hopf theory. It is shown that an invariant set of stationary points bifurcates into an invariant torus (doubly-periodic branching solution). Influence of the symmetry breaking on stability of branching solutions is investigated as a function of detuning. The invariant torus is found to be stable under the detuning exceeds its critical value, so that dynamically broken symmetry results in the apprearance of low-frequency Goldstone-type mode. If the detuning then goes downward and pumping is kept above the threshold, numerical analysis reveals that after a cascade of period-doublings the strange Lorenz attractor is formed at small values of detuning. It is found that there are three types of the system behavior as pumping increases depending on the detuning. Quantum counterpart of the complex Lorenz model is discussed.

Alexei D. Kiselev

1998-01-15T23:59:59.000Z

472

Critical region for an Ising model coupled to causal dynamical triangulations  

E-Print Network (OSTI)

A lower and an upper bound are established upon a critical curve for the (annealed) Ising model coupled to two-dimensional causal dynamical triangulations. Using the Fortuin-Kasteleyn (FK) representation of quantum Ising models via path integrals, we determine a region in the quadrant of parameters $\\beta, \\mu>0$ where the critical curve can be located. Moreover, this approach serves to outline a region where the infinite-volume Gibbs measure exist and is unique and a region where the finite-volume Gibbs measure has no weak limit. We also provide lower and upper bounds for the infinite-volume free energy.

José Cerda Hernández

2014-02-13T23:59:59.000Z

473

The microenvironmental modelling approach to assess children's exposure to air pollution – A review  

Science Journals Connector (OSTI)

Abstract Exposures to a wide spectrum of air pollutants were associated to several effects on children's health. Exposure assessment can be used to establish where and how air pollutants' exposures occur. However, a realistic estimation of children's exposures to air pollution is usually a great ethics challenge, especially for young children, because they cannot intentionally be exposed to contaminants and according to Helsinki declaration, they are not old enough to make a decision on their participation. Additionally, using adult surrogates introduces bias, since time–space–activity patterns are different from those of children. From all the different available approaches for exposure assessment, the microenvironmental (ME) modelling (indirect approach, where personal exposures are estimated or predicted from microenvironment measurements combined with time–activity data) seemed to be the best to assess children's exposure to air pollution as it takes into account the varying levels of pollution to which an individual is exposed during the course of the day, it is faster and less expensive. Thus, this review aimed to explore the use of the ME modelling approach methodology to assess children's exposure to air pollution. To meet this goal, a total of 152 articles, published since 2002, were identified and titles and abstracts were scanned for relevance. After exclusions, 26 articles were fully reviewed and main characteristics were detailed, namely: (i) study design and outcomes, including location, study population, calendar time, pollutants analysed and purpose; and (ii) data collection, including time–activity patterns (methods of collection, record time and key elements) and pollution measurements (microenvironments, methods of collection and duration and time resolution). The reviewed studies were from different parts of the world, confirming the worldwide application, and mostly cross-sectional. Longitudinal studies were also found enhancing the applicability of this approach. The application of this methodology on children is different from that on adults because of data collection, namely the methods used for collecting time–activity patterns must be different and the time–activity patterns are itself different, which leads to select different microenvironments to the data collection of pollutants' concentrations. The most used methods to gather information on time–activity patterns were questionnaires and diaries, and the main microenvironments considered were home and school (indoors and outdoors). Although the ME modelling approach in studies to assess children’s exposure to air pollution is highly encouraged, a validation process is needed, due to the uncertainties associated with the application of this approach.

P.T.B.S. Branco; M.C.M. Alvim-Ferraz; F.G. Martins; S.I.V. Sousa

2014-01-01T23:59:59.000Z

474

Modeling the dynamic response of pressures in a distributed helium refrigeration system  

SciTech Connect

A mathematical model is created of the dynamic response of pressures caused by flow inputs to an existing distributed helium refrigeration system. The dynamic system studied consists of the suction and discharge pressure headers and compressor portions of the refrigeration system used to cool the superconducting magnets of the Tevatron accelerator at the Fermi National Accelerator Laboratory. The modeling method involves identifying the system from data recorded during a series of controlled tests, with effort made to detect locational differences in pressure response around the four mile accelerator circumference. A review of the fluid mechanics associated with the system indicates linear time invariant models are suitable for the identification, particularly since the governing equations of one dimensional fluid flow are approximated by linear differential equations. An outline of the experimental design and the data acquisition system are given, followed by a detailed description of the modeling, which utilized the Matlab programming language and associated System Identification Toolbox. Two representations of the system are presented. One, a black box model, provides a multi-input, multi-output description assembled from the results of single input step function testing. This description indicates definite variation in pressure response with distance from the flow input location, and also suggests subtle differences in response with the input location itself. A second system representation is proposed which details the relation between continuous flow changes and pressure response, and provides explanation of a previously unappreciated pressure feedback internal to the system.

Brubaker, J.C.

1997-12-01T23:59:59.000Z

475

A Home Ignition Assessment Model Applied to Structures in the Wildland-Urban Interface  

SciTech Connect

The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structure fires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. The WIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to their homes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reduce the threat. The inputs include the structural and material features of the home and information about any ignition sources or flammable objects in its immediate vicinity, known as the home ignition zone. The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heating of the building envelope from the potential ignition sources. This article describes a series of material ignition and flammability tests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls with different external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determine the conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify the model predictions of temperature rises and ignition times of the test walls.

Biswas, Kaushik [ORNL; Werth, David [Savannah River National Laboratory, Aiken, SC; Gupta, Narendra [Savannah River National Laboratory, Aiken, SC

2013-01-01T23:59:59.000Z

476

Implementation of Localized Corrosion in the Performance Assessment Model for Yucca Mountain  

SciTech Connect

A total system performance assessment (TSPA) model has been developed to analyze the ability of the natural and engineered barriers of the Yucca Mountain repository to isolate nuclear waste over the 10,000-year period following repository closure. The principal features of the engineered barrier system (EBS) are emplacement tunnels (or ''drifts'') containing a two-layer waste package (WP) for waste containment and a titanium drip shield to protect the waste package from seeping water and falling rock, The 20-mm-thick outer shell of the WP is composed of Alloy 22, a highly corrosion-resistant nickel-based alloy. The barrier function of the EBS is to isolate the waste from migrating water. The water and its associated chemical conditions eventually lead to degradation of the waste packages and mobilization of the radionuclides within the packages. There are five possible waste package degradation modes of the Alloy 22: general corrosion, microbially influenced corrosion, stress corrosion cracking, early failure due to manufacturing defects, and localized corrosion. This paper specifically examines the incorporation of the Alloy-22 localized corrosion model into the Yucca Mountain TSPA model, particularly the abstraction and modeling methodology, as well as issues dealing with scaling, spatial variability, uncertainty, and coupling to other sub-models that are part of the total system model.

Vivek Jain, S. David Sevougian, Patrick D. Mattie, Kevin G. Mon, and Robert J. Mackinnon

2006-04-30T23:59:59.000Z

477

Utilizing geographic information systems technology in the Wyoming cumulative hydrologic impact assessment modeling process  

SciTech Connect

The coal-permitting process places heavy demands on both permit applicants and regulatory authorities with respect to the management and analysis of hydrologic data. Currently, this correlation is being addressed for the Powder River Basin, Wyoming by the ongoing Cumulative Hydrologic Impact Assessment (CHIA) efforts at the University of Wyoming. One critical component of the CHIA is the use of a Geographic Information System (GIS) for support, management, manipulation, pre-analysis, and display of data associated with the chosen groundwater and surface water models. This paper will discuss the methodology in using of GIS technology as an integrated tool with the MODFLOW and HEC-1 hydrologic models. Pre-existing GIS links associated with these two models served as a foundation for this effort. However, due to established standards and site specific factors, substantial modifications were performed on existing tools to obtain adequate results. The groundwater-modeling effort required the use of a refined grid in which cell sizes varied based on the relative locations of ongoing mining activities. Surface water modeling was performed in a semi-arid region with very limited topographic relief and predominantly ephemeral stream channels. These were substantial issues that presented challenges for effective GIS/model integration.

Hamerlinck, J.D.; Oakleaf, J.R. [Univ. of Wyoming, Laramie, WY (United States)

1997-12-31T23:59:59.000Z

478

Multi-State Physics Models of Aging Passive Components in Probabilistic Risk Assessment  

SciTech Connect

Multi-state Markov modeling has proved to be a promising approach to estimating the reliability of passive components - particularly metallic pipe components - in the context of probabilistic risk assessment (PRA). These models consider the progressive degradation of a component through a series of observable discrete states, such as detectable flaw, leak and rupture. Service data then generally provides the basis for estimating the state transition rates. Research in materials science is producing a growing understanding of the physical phenomena that govern the aging degradation of passive pipe components. As a result, there is an emerging opportunity to incorporate these insights into PRA. This paper describes research conducted under the Risk-Informed Safety Margin Characterization Pathway of the Department of Energy’s Light Water Reactor Sustainability Program. A state transition model is described that addresses aging behavior associated with stress corrosion cracking in ASME Class 1 dissimilar metal welds – a component type relevant to LOCA analysis. The state transition rate estimates are based on physics models of weld degradation rather than service data. The resultant model is found to be non-Markov in that the transition rates are time-inhomogeneous and stochastic. Numerical solutions to the model provide insight into the effect of aging on component reliability.

Unwin, Stephen D.; Lowry, Peter P.; Layton, Robert F.; Heasler, Patrick G.; Toloczko, Mychailo B.

2011-03-13T23:59:59.000Z

479

Economic analysis and assessment of syngas production using a modeling approach  

SciTech Connect

Economic analysis and modeling are essential and important issues for the development of current feedstock and process technology for bio-gasification. The objective of this study was to develop an economic model and apply to predict the unit cost of syngas production from a micro-scale bio-gasification facility. An economic model was programmed in C++ computer programming language and developed using a parametric cost approach, which included processes to calculate the total capital costs and the total operating costs. The model used measured economic data from the bio-gasification facility at Mississippi State University. The modeling results showed that the unit cost of syngas production was $1.217 for a 60 Nm-3 h-1 capacity bio-gasifier. The operating cost was the major part of the total production cost. The equipment purchase cost and the labor cost were the largest part of the total capital cost and the total operating cost, respectively. Sensitivity analysis indicated that labor costs rank the top as followed by equipment cost, loan life, feedstock cost, interest rate, utility cost, and waste treatment cost. The unit cost of syngas production increased with the increase of all parameters with exception of loan life. The annual cost regarding equipment, labor, feedstock, waste treatment, and utility cost showed a linear relationship with percent changes, while loan life and annual interest rate showed a non-linear relationship. This study provides the useful information for economic analysis and assessment of the syngas production using a modeling approach.

Kim, Hakkwan; Parajuli, Prem B.; Yu, Fei; Columbus, Eugene P.

2011-08-10T23:59:59.000Z

480

Parametric modeling of transitioning cyclone’s wind fields for risk assessment studies in the western North Pacific  

Science Journals Connector (OSTI)

Probabilistic risk assessment systems for tropical cyclone hazard rely on large ensembles of model simulations to characterize cyclones tracks, intensities and the extent of the associated damaging winds. Given computational costs the wind field ...

T. Loridan; S. Khare; E. Scherer; M. Dixon; E. Bellone

Note: This page contains sample records for the topic "dynamics models assessing" 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

Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.113  

SciTech Connect

Preliminary results for Version 4.113 of the Nevada National Security Site Area 5 Radioactive Waste Management Site performance assessment model are summarized. Version 4.113 includes the Fiscal Year 2011 inventory estimate.

Shott, G. J.

2012-04-15T23:59:59.000Z

482

A validated dynamic model of the first marine molten carbonate fuel cell  

Science Journals Connector (OSTI)

In this work we present a modular, dynamic and multi-dimensional model of a molten carbonate fuel cell (MCFC) onboard the offshore supply vessel “Viking Lady” serving as an auxiliary power unit. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the vessel. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the offshore supply vessel. The calibration process included parameter identification, sensitivity analysis to identify the critical model parameters, and iterative calibration of these to minimize the overall prediction error. The calibrated model has a low prediction error of 4% for the operating range of the cell, exhibiting at the same time a physically sound qualitative behavior in terms of thermodynamic heat transfer and electrochemical phenomena, both on steady-state and transient operation. The developed model is suitable for a wide range of studies covering the aspects of thermal efficiency, performance, operability, safety and endurance/degradation, which are necessary to introduce fuel cells in ships. The aim of this MCFC model is to aid to the introduction, design, concept approval and verification of environmentally friendly marine applications such as fuel cells, in a cost-effective, fast and safe manner.

E. Ovrum; G. Dimopoulos

2012-01-01T23:59:59.000Z