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


1

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.

2

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.

3

Modeling and optimization with Optimica and JModelica.org—Languages and tools for solving large-scale dynamic optimization problems  

Science Journals Connector (OSTI)

The Modelica language, targeted at modeling of complex physical systems, has gained increased attention during the last decade. Modelica is about to establish itself as a de facto standard in the modeling community with strong support both within academia and industry. While there are several tools, both commercial and free, supporting simulation of Modelica models few efforts have been made in the area of dynamic optimization of Modelica models. In this paper, an extension to the Modelica language, entitled Optimica, is reported. Optimica enables compact and intuitive formulations of optimization problems, static and dynamic, based on Modelica models. The paper also reports a novel Modelica-based open source project, JModelica.org, specifically targeted at dynamic optimization. JModelica.org supports the Optimica extension and offers an open platform based on established technologies, including Python, C, Java and XML. Examples are provided to demonstrate the capabilities of Optimica and JModelica.org.

J. Åkesson; K.-E. Årzén; M. Gäfvert; T. Bergdahl; H. Tummescheit

2010-01-01T23:59:59.000Z

4

Optimization Online - Multilevel Optimization Modeling for Risk ...  

E-Print Network [OSTI]

Abstract: Coherent risk measures have become a popular tool for incorporating risk aversion into stochastic optimization models. For dynamic models in which ...

Jonathan Eckstein

5

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

6

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

7

A dynamic model for optimally phasing in CO2 capture and storage infrastructure  

Science Journals Connector (OSTI)

CO"2 capture and storage (CCS) is a climate-change mitigation strategy that requires an investment of many billions of dollars and tens of thousands of miles of dedicated CO"2 pipelines. To be effective, scientists, stakeholders, and policy makers will ... Keywords: CO2 capture and storage, Climate-change policy, Infrastructure modeling, Pipeline modeling, SimCCS, Spatiotemporal optimization

Richard S. Middleton; Michael J. Kuby; Ran Wei; Gordon N. Keating; Rajesh J. Pawar

2012-11-01T23:59:59.000Z

8

Dynamic modeling and optimal control of DFIG wind energy systems using DFT and NSGA-II  

Science Journals Connector (OSTI)

Abstract Once a doubly-fed induction generator (DFIG) is subjected to a disturbance by a change in the wind speed, the stator flux cannot change instantly. Under this condition, rotor back-EMF voltages reflect the effects of stator dynamics on rotor current dynamics, and have an important role on the oscillations of the rotor current. These oscillations decrease the DFIG system reliability and gear lifetime. Moreover, by focusing only on small signal analysis, the dynamic damping performance immediately following such disturbances is often degraded. Additional improvement in performance will be achieved if discrete Fourier transform (DFT) is used to quantify damping characteristic of the rotor current during changes of the operating points. This paper introduces an optimization technique based on non-dominated sorting genetic algorithm-II (NSGA-II) incorporating DFT analysis to achieve better control performance for DFIG system stability. Considering small signal stability, the main purpose of the control system in the present paper is to increase the system damping ratio as well as to guarantee enough stability margin. Eigenvalue analysis and time-domain simulations have been presented to demonstrate that the proposed optimizing method yields better control performance in comparison with one designed using mere eigenvalue relocation.

M. Zamanifar; B. Fani; M.E.H. Golshan; H.R. Karshenas

2014-01-01T23:59:59.000Z

9

Development of a Dynamic DOE Calibration Model  

Broader source: Energy.gov [DOE]

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

10

Optimization models in finance Ma 450 Darinka Dentcheva Fall 2012 darinka.dentcheva@stevens.edu  

E-Print Network [OSTI]

Optimization models in finance Ma 450 Darinka Dentcheva Fall 2012 darinka and dynamic optimization problems occurring in finance. We shall discuss linear and non-linear optimization models of finance, dynamic (se- quential) optimization, optimization under uncertainty, mathematical

Dentcheva, Darinka

11

Robust optimization of the rate of penetration of a drill-string using a stochastic nonlinear dynamical model  

Science Journals Connector (OSTI)

This work proposes a strategy for the robust optimization of the nonlinear dynamics of a drill-string, which is a structure that rotates and digs into the rock to search for oil. The nonparametric probabilistic a...

T. G. Ritto; Christian Soize; R. Sampaio

2010-04-01T23:59:59.000Z

12

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

13

Optimization Online - Python Optimization Modeling Objects (Pyomo)  

E-Print Network [OSTI]

Dec 30, 2009 ... Abstract: We describe Pyomo, an open source tool for modeling optimization applications in Python. Pyomo can be used to de fine symbolic ...

William Hart

2009-12-30T23:59:59.000Z

14

Optimization Online - Dynamic Generation of Scenario Trees  

E-Print Network [OSTI]

Sep 3, 2014 ... Abstract: We present new algorithms for the dynamic generation of scenario trees for multistage stochastic optimization. The different methods ...

G. Ch. Pflug

2014-09-03T23:59:59.000Z

15

HOMER® Micropower Optimization Model  

SciTech Connect (OSTI)

NREL has developed the HOMER micropower optimization model. The model can analyze all of the available small power technologies individually and in hybrid configurations to identify least-cost solutions to energy requirements. This capability is valuable to a diverse set of energy professionals and applications. NREL has actively supported its growing user base and developed training programs around the model. These activities are helping to grow the global market for solar technologies.

Lilienthal, P.

2005-01-01T23:59:59.000Z

16

Optimization of Variational Boussinesq Models  

E-Print Network [OSTI]

Optimization of Variational Boussinesq Models 2 4 6 8 10 2 4 6 8 10 0 0.5 1 1.5 2 1 2 Kapp -Kex 0 of Arts and Sciences). Ivan Lakhturov: Optimization of Variational Boussinesq Models c 2012 Printed Boussinesq Model (VBM). The VBM is a model for waves above a layer of ideal fluid, which conserves mass

Al Hanbali, Ahmad

17

Optimization Models in Finance (26:711:564) Andrzej Ruszczynski  

E-Print Network [OSTI]

Optimization Models in Finance (26:711:564) Andrzej Ruszczynski Objectives The objective of this course is to introduce models and computational methods for static and dynamic optimization problems occurring in finance. Special attention will be devoted to portfolio optimization and to risk management

Lin, Xiaodong

18

Energy systems planning and GHG-emission control under uncertainty in the province of Liaoning, China – A dynamic inexact energy systems optimization model  

Science Journals Connector (OSTI)

Abstract In this study, a dynamic interval-parameter optimization model (DIP-REM) has been developed for supporting long-term energy systems planning in association with GHG mitigation in the region of Liaoning province. The model can describe Liaoning province energy planning systems as networks of a series of energy flows, transferring extracted/imported energy resources to end users through a variety of conversion and transmission technologies over a number of periods and address the problem of GHG-emission reduction within a general energy planning systems framework under uncertainty. Two scenarios (including a reference case) are considered corresponding to different GHG-emission mitigation levels for in-depth analysis of interactions existing among energy, socio-economy and environment in the Liaoning province. Useful solutions for Liaoning province energy planning systems have been generated, reflecting trade-offs among energy-related, environmental and economic considerations. The results can not only provide optimal energy resource/service allocation and capacity-expansion plans, but also help decision-makers identify desired policies for GHG mitigation with a cost-effective manner in the region of Liaoning province. Thus, it can be used by decision makers as an effective technique in examining and visualizing impacts of energy and environmental policies, regional development strategies and emission reduction measures within an integrated and dynamic framework.

J. Liu; Q.G. Lin; G.H. Huang; Q. Wu; H.P. Li

2013-01-01T23:59:59.000Z

19

Chaotic Dynamics in Optimal Monetary Policy  

E-Print Network [OSTI]

There is by now a large consensus in modern monetary policy. This consensus has been built upon a dynamic general equilibrium model of optimal monetary policy as developed by, e.g., Goodfriend and King (1997), Clarida et al. (1999), Svensson (1999) and Woodford (2003). In this paper we extend the standard optimal monetary policy model by introducing nonlinearity into the Phillips curve. Under the specific form of nonlinearity proposed in our paper (which allows for convexity and concavity and secures closed form solutions), we show that the introduction of a nonlinear Phillips curve into the structure of the standard model in a discrete time and deterministic framework produces radical changes to the major conclusions regarding stability and the efficiency of monetary policy. We emphasize the following main results: (i) instead of a unique fixed point we end up with multiple equilibria; (ii) instead of saddle--path stability, for different sets of parameter values we may have saddle stability, totally unstable equilibria and chaotic attractors; (iii) for certain degrees of convexity and/or concavity of the Phillips curve, where endogenous fluctuations arise, one is able to encounter various results that seem intuitively correct. Firstly, when the Central Bank pays attention essentially to inflation targeting, the inflation rate has a lower mean and is less volatile; secondly, when the degree of price stickiness is high, the inflation rate displays a larger mean and higher volatility (but this is sensitive to the values given to the parameters of the model); and thirdly, the higher the target value of the output gap chosen by the Central Bank, the higher is the inflation rate and its volatility.

Orlando Gomes; Vivaldo M. Mendes; Diana A. Mendes; J. Sousa Ramos

2006-07-28T23:59:59.000Z

20

DYNAMIC PROGRAMMING ALGORITHM FOR RATE-DISTORTION OPTIMIZED MEDIA STREAMING  

E-Print Network [OSTI]

a dynamic programming algorithm for finding optimal transmission policies for a single packet in rate the assumption as a heuris- tic principle. Simulations show that for realistic channel models, the algorithm multimedia services over the Internet [1]. In contrast to traditional video transmission systems, a video

Reiterer, Harald

Note: This page contains sample records for the topic "dynamic optimization model" 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

AVESTAR® - Dynamic Modeling  

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

22

Optimized dynamic semantic composition of services  

Science Journals Connector (OSTI)

This paper proposes a design for the optimized dynamic (re)composition of services that supports various user requests and accounts for changes in user's context. The composition mechanism relies on semantic descriptions of services' functionality to ... Keywords: context-awareness, domain ontology, semantic similarity, service composition, services

Sorin M. Iacob; João Paulo A. Almeida; Maria E. Iacob

2008-03-01T23:59:59.000Z

23

Toward optimized code generation through model-based optimization  

E-Print Network [OSTI]

Toward optimized code generation through model- based optimization Asma Charfi, Chokri Mraidha with in RTES development is linked to the optimization of their software part. Although automatic code generation and the use of optimizing compilers bring some answers to application optimization issue, we

Paris-Sud XI, Université de

24

Set Covering and Network Optimization: Dynamic and Approximation Algorithms  

E-Print Network [OSTI]

Set Covering and Network Optimization: Dynamic and Approximation Algorithms Orestis A. Telelis summarize our results on development and analysis of approximation and dynamic algorithms for set covering and network optimization problems. The results include probabilistic analysis of set covering algorithms

Kouroupetroglou, Georgios

25

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

26

Optimization of Modelica Models with JModelica.org and Optimica  

E-Print Network [OSTI]

-based modeling ­ Text book style equations · Multi-domain modeling ­ Heterogeneous modeling · Object orientedOptimization of Modelica Models with JModelica.org and Optimica #12;Outline · Modelica · Dynamic's next? #12;What is Modelica? · A language for modeling of complex heterogeneous physical systems · Open

27

Luo and Zhang: DSM and Optimization 1 Dynamic Spectrum Management  

E-Print Network [OSTI]

Luo and Zhang: DSM and Optimization 1 Dynamic Spectrum Management: Complexity, Duality and Zhang: DSM and Optimization 2 Dynamic Spectrum Management (DSM) Multiuser communication system: · K interferences. Shuzhong Zhang, The Chinese University of Hong Kong #12;Luo and Zhang: DSM and Optimization 3

Zhang, Shuzhong

28

Optimal consumption strategies under model uncertainty  

E-Print Network [OSTI]

Optimal consumption strategies under model uncertainty Christian Burgert, Ludger R of finding optimal consumption strategies in an incomplete semimartingale market model under model uncertainty. The quality of a consumption strategy is measured by not only one probability measure

Rüschendorf, Ludger

29

Biotrans: Cost Optimization Model | Open Energy Information  

Open Energy Info (EERE)

Biotrans: Cost Optimization Model Biotrans: Cost Optimization Model Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Biotrans: Cost Optimization Model Focus Area: Ethanol Topics: Market Analysis Website: www.ecn.nl/units/ps/models-and-tools/biotrans/ Equivalent URI: cleanenergysolutions.org/content/biotrans-cost-optimization-model,http Language: English Policies: Deployment Programs DeploymentPrograms: Demonstration & Implementation BIOTRANS optimizes the biofuel supply chain allocation by finding the least-cost configuration of resources and trade to meet a specified biofuel demand in the European transportation sector. The user can constrain the optimization by inputting a number of economic and technological assumptions for a specific target year. References Retrieved from

30

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

31

Optimization Modeling Languages Emmanuel Fragni`ere  

E-Print Network [OSTI]

Optimization Modeling Languages Emmanuel Fragni`ere HEC, Department of Management, University, 1999 1 #12;Abstract The access to advanced optimization software needs more and more sophisticated modeling tools. Optimization modeling languages are tools that facilitate the decision making process based

Gondzio, Jacek

32

Optimization of Structural Dynamic Behaviour Based on Effective Modal Parameters  

E-Print Network [OSTI]

Optimization of Structural Dynamic Behaviour Based on Effective Modal Parameters S. Besset, L. J Optimization of complex structures often leads to high calculation costs. In- deed, the structure has to be frequently reanalysed in order to update the opti- mization criteriums. We propose an optimization method

Paris-Sud XI, Université de

33

Optimized Uncertainty Quantification Algorithm Within a Dynamic Event Tree Framework  

SciTech Connect (OSTI)

Methods for developing Phenomenological Identification and Ranking Tables (PIRT) for nuclear power plants have been a useful tool in providing insight into modelling aspects that are important to safety. These methods have involved expert knowledge with regards to reactor plant transients and thermal-hydraulic codes to identify are of highest importance. Quantified PIRT provides for rigorous method for quantifying the phenomena that can have the greatest impact. The transients that are evaluated and the timing of those events are typically developed in collaboration with the Probabilistic Risk Analysis. Though quite effective in evaluating risk, traditional PRA methods lack the capability to evaluate complex dynamic systems where end states may vary as a function of transition time from physical state to physical state . Dynamic PRA (DPRA) methods provide a more rigorous analysis of complex dynamic systems. A limitation of DPRA is its potential for state or combinatorial explosion that grows as a function of the number of components; as well as, the sampling of transition times from state-to-state of the entire system. This paper presents a method for performing QPIRT within a dynamic event tree framework such that timing events which result in the highest probabilities of failure are captured and a QPIRT is performed simultaneously while performing a discrete dynamic event tree evaluation. The resulting simulation results in a formal QPIRT for each end state. The use of dynamic event trees results in state explosion as the number of possible component states increases. This paper utilizes a branch and bound algorithm to optimize the solution of the dynamic event trees. The paper summarizes the methods used to implement the branch-and-bound algorithm in solving the discrete dynamic event trees.

J. W. Nielsen; Akira Tokuhiro; Robert Hiromoto

2014-06-01T23:59:59.000Z

34

Optimization of naïve dynamic binary instrumentation Tools/  

E-Print Network [OSTI]

The proliferation of dynamic program analysis tools has done much to ease the burden of developing complex software. However, creating such tools remains a challenge. Dynamic binary instrumentation frameworks such as ...

Kleckner, Reid (Reid N.)

2011-01-01T23:59:59.000Z

35

First principles molecular dynamics without self-consistent field optimization  

SciTech Connect (OSTI)

We present a first principles molecular dynamics approach that is based on time-reversible extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] in the limit of vanishing self-consistent field optimization. The optimization-free dynamics keeps the computational cost to a minimum and typically provides molecular trajectories that closely follow the exact Born-Oppenheimer potential energy surface. Only one single diagonalization and Hamiltonian (or Fockian) construction are required in each integration time step. The proposed dynamics is derived for a general free-energy potential surface valid at finite electronic temperatures within hybrid density functional theory. Even in the event of irregular functional behavior that may cause a dynamical instability, the optimization-free limit represents a natural starting guess for force calculations that may require a more elaborate iterative electronic ground state optimization. Our optimization-free dynamics thus represents a flexible theoretical framework for a broad and general class of ab initio molecular dynamics simulations.

Souvatzis, Petros, E-mail: petros.souvatsiz@fysik.uu.se [Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)] [Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Niklasson, Anders M. N., E-mail: amn@lanl.gov [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-01-28T23:59:59.000Z

36

Modeling and optimization of building HVAC systems.  

E-Print Network [OSTI]

??This thesis presents the development of hybrid modeling methodologies for HVAC component static/steady-state models and dynamic/transient models, and the development and implementation of a model-based… (more)

Jin, Guang Yu.

2012-01-01T23:59:59.000Z

37

Simple Dynamic Gasifier Model That Runs in Aspen Dynamics  

SciTech Connect (OSTI)

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

38

Optimal Shipboard Power System Management via Mixed Integer Dynamic Programming  

E-Print Network [OSTI]

Optimal Shipboard Power System Management via Mixed Integer Dynamic Programming Harry G. Kwatny' power systems using a logical specification to define the transition dynamics of the discrete subsystem following component failure(s) is a central goal of power system management including electric shipboard

Kwatny, Harry G.

39

Optimizing MATLAB feval with Dynamic Techniques Nurudeen Lameed Laurie Hendren  

E-Print Network [OSTI]

Optimizing MATLAB feval with Dynamic Techniques Nurudeen Lameed Laurie Hendren Sable Research Group,hendren}@cs.mcgill.ca, http://www.sable.mcgill.ca/mclab Abstract MATLAB is a popular dynamic array-based language used by en- gineers, scientists and students worldwide. The built-in function feval is an important MATLAB feature

40

An Infrastructure for Adaptive Dynamic Optimization  

E-Print Network [OSTI]

Amarasinghe Laboratory for Computer Science Massachusetts Institute of Technology Cambridge, MA 02139 {iye and can be used for instru- mentation, profiling, dynamic translation, etc. To demonstrate the usefulness, which heavily utilizes dynamic class loading, shared libraries, and runtime binding. Not only

Amarasinghe, Saman

Note: This page contains sample records for the topic "dynamic optimization model" 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

Python Optimization Modeling Objects (Pyomo)  

E-Print Network [OSTI]

Dec 29, 2009 ... The introduction of Pyomo was motivated by a variety of factors that have impacted ..... detection of available optimizers, conversion to file formats needed by ..... Company, for the United States Department of Energy's National.

2009-12-29T23:59:59.000Z

42

Optimizing Probabilistic Models for Relational Sequence Learning  

E-Print Network [OSTI]

Optimizing Probabilistic Models for Relational Sequence Learning Nicola Di Mauro, Teresa M features, a feature #12;2 Nicola Di Mauro, Teresa M.A. Basile, Stefano Ferilli, and Floriana Esposito

Di Mauro, Nicola

43

Nonlinear Optimization in Modeling Environments  

E-Print Network [OSTI]

Dec 16, 2004 ... processes, including also living organisms of all scales. .... of a complex system of program code, stochastic simulation, .... Maple (Maplesoft, 2004), Mathematica (Wolfram Research, 2004), and MATLAB (The ..... Edgar, T.F., Himmelblau, D.M., and Lasdon, L.S. (2001) Optimization of Chemical Processes.

Administrator

2005-01-26T23:59:59.000Z

44

Study on Revolving Reserve Optimization Model Considering Demand Response  

Science Journals Connector (OSTI)

Traditional dispatching model could not suit the requirement in power market, optimal dispatching model considering demand response has been established by using optimal theories...

Na Yu; Guoqing Li

2013-01-01T23:59:59.000Z

45

Modeling and optimization of HVAC energy consumption  

Science Journals Connector (OSTI)

A data-driven approach for minimization of the energy to air condition a typical office-type facility is presented. Eight data-mining algorithms are applied to model the nonlinear relationship among energy consumption, control settings (supply air temperature and supply air static pressure), and a set of uncontrollable parameters. The multiple-linear perceptron (MLP) ensemble outperforms other models tested in this research, and therefore it is selected to model a chiller, a pump, a fan, and a reheat device. These four models are integrated into an energy optimization model with two decision variables, the setpoint of the supply air temperature and the static pressure in the air handling unit. The model is solved with a particle swarm optimization algorithm. The optimization results have demonstrated the total energy consumed by the heating, ventilation, and air-conditioning system is reduced by over 7%.

Andrew Kusiak; Mingyang Li; Fan Tang

2010-01-01T23:59:59.000Z

46

Optimization of flagellar swimming by a model sperm  

E-Print Network [OSTI]

The swimming of a bead-spring chain in a viscous incompressible fluid as a model of a sperm is studied in the framework of low Reynolds number hydrodynamics. The optimal mode in the class of planar flagellar strokes of small amplitude is determined on the basis of a generalized eigenvalue problem involving two matrices which can be evaluated from the mobility matrix of the set of spheres constituting the chain. For an elastic chain with a cargo constraint for its spherical head, the actuating forces yielding a nearly optimal stroke can be determined. These can be used in a Stokesian dynamics simulation of large amplitude swimming.

B. U. Felderhof

2014-12-12T23:59:59.000Z

47

Optimal PMU Placement Evaluation for Power System Dynamic State Estimation  

E-Print Network [OSTI]

Optimal PMU Placement Evaluation for Power System Dynamic State Estimation Jinghe Zhang, Student--The synchronized phasor measurement unit (PMU), developed in the 1980s, is considered to be one of the most important devices in the future of power systems. The recent development of PMU technology provides high

Bishop, Gary

48

A Dynamic Programming Framework for Combinatorial Optimization ...  

E-Print Network [OSTI]

responding graph model can be used in order to define effec- tive network .... meaning that there exists (does not exist) a coloring of the ver- tices in UDi, such

Mugurel

2008-05-20T23:59:59.000Z

49

Fuel Optimal Thrust Allocation in Dynamic Positioning  

E-Print Network [OSTI]

vessels with diesel-electric power system. In this paper the focus is on using the thrust allocation to make the diesel generators on board the vessel work more fuel efficiently, by reducing the total fuel consumption of all online diesel generators. A static model for the fuel consumption of a diesel generator

Johansen, Tor Arne

50

Modeling and Optimization of SemiModeling and Optimization of SemiModeling and Optimization of SemiModeling and Optimization of Semi----Interpenetrating Polymer Network (SIPN)Interpenetrating Polymer Network (SIPN)Interpenetrating Polymer Network (SIPN)In  

E-Print Network [OSTI]

Modeling and Optimization of SemiModeling and Optimization of SemiModeling and Optimization of SemiModeling and Optimization of Semi---- Interpenetrating Polymer Network (SIPN)Interpenetrating Polymer Network (SIPN suspension polymerization -- In situ reaction Monomer Initiator Polymerization reactor Project Overview 4

Grossmann, Ignacio E.

51

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

52

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

53

Wind-Wave Model with an Optimized Source Function  

E-Print Network [OSTI]

On the basis of the author's earlier results, a new source function for a numerical wind-wave model optimized by the criterion of accuracy and speed of calculation is substantiated. The proposed source function includes (a) an optimized version of the discrete interaction approximation for parametrization of the nonlinear evolution mechanism, (b) a generalized empirical form of the input term modified by adding a special block of the dynamic boundary layer of the atmosphere, and (c) a dissipation term quadratic in the wave spectrum. Particular attention is given to a theoretical substantiation of the least investigated dissipation term. The advantages of the proposed source function are discussed by its comparison to the analogues used in the widespread models of the third generation WAM and WAVEWATCH. At the initial stage of assessing the merits of the proposed model, the results of its testing by the system of academic tests are presented. In the course of testing, some principals of this procedure are form...

Polnikov, Vladislav

2010-01-01T23:59:59.000Z

54

Dynamic Response Optimization of Complex Multibody Systems in a Penalty Formulation using Adjoint Sensitivity  

E-Print Network [OSTI]

Multibody dynamics simulations are currently widely accepted as valuable means for dynamic performance analysis of mechanical systems. The evolution of theoretical and computational aspects of the multibody dynamics discipline make it conducive these days for other types of applications, in addition to pure simulations. One very important such application is design optimization. A very important first step towards design optimization is sensitivity analysis of multibody system dynamics. Dynamic sensitivities are often calculated by means of finite differences. Depending of the number of parameters involved, this procedure can be computationally expensive. Moreover, in many cases, the results suffer from low accuracy when real perturbations are used. The main contribution to the state-of-the-art brought by this study is the development of the adjoint sensitivity approach of multibody systems in the context of the penalty formulation. The theory developed is demonstrated on one academic case study, a five-bar mechanism, and on one real-life system, a 14-DOF vehicle model. The five-bar mechanism is used to illustrate the sensitivity approach derived in this paper. The full vehicle model is used to demonstrate the capability of the new approach developed to perform sensitivity analysis and gradient-based optimization for large and complex multibody systems with respect to multiple design parameters.

Yitao Zhu; Daniel Dopico; Corina Sandu; Adrian Sandu

2014-10-30T23:59:59.000Z

55

Dynamic optimization of heated oil pipeline operation using PSO–DE algorithm  

Science Journals Connector (OSTI)

Abstract Crude oil, with relatively high viscosity, freezing-point and content of wax, is usually transported by heated oil pipelines (HOP) containing many pumping and heating stations. There are many different selections of operation parameters or values of pumps and heating furnaces, but all these different “selections” can satisfy output task and safety requirements. The power and fuel cost of pumping and heating account for 1–3% of the total energy consumption. For the energy saving purpose, it is necessary to optimize the HOP operations. In this paper a dynamic model of HOP was proposed and used to calculate the soil temperature field outside HOP, and then both the spatial and temporal distributions of pressure and temperature of field inside HOP. Using this calculation method and its results, an optimization model is established aiming at minimizing energy cost of running HOP, with outlet temperatures of each heating station, on–off states of each pump, and their head matrix of delivery as the optimization variables. Then a mixed algorithm combining differential evolution algorithm with particle swarm optimization algorithm is used to solve this model. The optimization results are applied to Rizhao–Yizheng digital long distance HOP (375 km). Research shows that: verified by real time data acquired by the SCADA, the relative error of the dynamic model’s result is 4.042%, much less than that of the steady-state model’s result (22.67%). The optimized operation scheme can save 17.59% of energy cost for oil transportation task of 2640 m3/h. Energy saving effect is remarkable.

Ming Zhou; Yu Zhang; Shijiu Jin

2015-01-01T23:59:59.000Z

56

Dynamic optimization of a plate reactor start-up  

E-Print Network [OSTI]

Dynamic optimization of a plate reactor start-up Staffan Haugwitz, Per Hagander and John Bagterp Jørgensen Lund-Lyngby-�lborg-dagen 061101 Staffan Haugwitz et al Control of a plate reactor #12;Process configurations : 2 inj. / 1 cool zone T T T T T T T T T T Reactor outletReactant A Reactant B Cooling water uB1 u

57

Gas Network Optimization: A comparison of Piecewise Linear Models  

E-Print Network [OSTI]

Oct 4, 2014 ... ... and advanced MILP formulations for the gas network optimization in dynamic or in steady-state conditions. ... Search, Browse the Repository.

CARLOS M. CORREA-POSADA

2014-10-04T23:59:59.000Z

58

Topology optimization of piezoelectric energy harvesting devices considering static and harmonic dynamic loads  

Science Journals Connector (OSTI)

A topology optimization (TO) procedure is developed to design optimal layouts for piezoelectric energy harvesting devices (EHDs) by considering the effect of static and harmonic dynamic mechanical loads. To determine the optimal material distributions ... Keywords: Energy harvesting device, Harmonic load, Piezoelectric material with penalization, Static load, Structural optimization, Topology optimization

Jin Yee Noh; Gil Ho Yoon

2012-11-01T23:59:59.000Z

59

Modeling Molecular Dynamics from Simulations  

SciTech Connect (OSTI)

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

60

Optimal Structural Nested Models for Optimal Sequential Decisions  

Science Journals Connector (OSTI)

I describe two new methods for estimating the optimal treatment regime (equivalently, protocol, plan or strategy) from very high dimesional observational and experimental data: (i) g-estimation of an optimal doub...

James M. Robins

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic optimization model" 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

Development of a Laboratory Verified Single-Duct VAV System Model with Fan Powered Terminal Units Optimized Using Computational Fluid Dynamics  

E-Print Network [OSTI]

model identified key parameters required to conduct numerical simulations of FPTU and some of the internal components used to manufacture the units. One key internal component was a porous baffle used to enhance mixing when primary air and induced air...

Davis, Michael A.

2011-10-21T23:59:59.000Z

62

Chapter Four - Model Transformation Using Multiobjective Optimization  

Science Journals Connector (OSTI)

Abstract The evolution of languages and software architectures provides a strong motivation to migrate/transform existing software systems. Thus, more attention is paid to the transformation aspects in model-driven engineering (MDE) along with the growing importance of modeling in software development. However, a major concern in MDE is how to ensure the quality of the model transformation mechanisms. Most of existing work in model transformation has relied on defining languages to express transformation rules. The main goal of existing transformation approaches is to provide rules generating target models, from source models, without errors. However, other important objective is how to minimize the complexity of transformation rules (e.g., the number of rules and number of matching in the same rule) while maximizing the quality of target models. In fact, reducing rule complexity and improving target model quality are important to (1) make rules and target models easy to understand and evolve, (2) find transformation errors easily, and (3) generate optimal target models. In this chapter, we consider the transformation mechanism as a multiobjective problem where the goal is to find the best rules maximizing target model quality and minimizing rule complexity. Our approach starts by randomly generating a set of rules, executing them to generate some target models. Of course, only solutions ensuring full correctness are considered during the optimization process. Then, the quality of the proposed solution (rules) is evaluated by (1) calculating the number of rules and matching metamodels in each rule and (2) assessing the quality of generated target models using a set of quality metrics. To this end, we use the nondominated sorting genetic algorithm (NSGA-II) to automatically generate the best transformation rules satisfying the two conflicting criteria. We report the results of our validation using three different transformation mechanisms. The best solutions provided well-designed target models with a minimal set of rules.

Mohamed Wiem Mkaouer; Marouane Kessentini

2014-01-01T23:59:59.000Z

63

OPTIMAL TRANSPORTATION AND DYNAMICS OF MAPS ACTING ON  

E-Print Network [OSTI]

CIRCLE MAPS by Beno^it Kloeckner Abstract. -- Given a map that acts on a compact polish space, one on a concrete example what one can expect from optimal transport in this context, we are interested in arguably.1.1. An important model example. -- Let us first consider the usual degree 2 self-covering map of the circle S1 = R

64

Dynamic online optimization of a house heating system in a fluctuating energy price  

E-Print Network [OSTI]

Dynamic online optimization of a house heating system in a fluctuating energy price scenario University of Science and Technology (NTNU), Trondheim, Norway Abstract: We consider dynamic optimization of the energy consumption in a building with energy storage capabilities. The goal is to find optimal policies

Skogestad, Sigurd

65

Mathematical Modeling for CostMathematical Modeling for Cost Optimization of PV RecyclingOptimization of PV Recycling  

E-Print Network [OSTI]

Mathematical Modeling for CostMathematical Modeling for Cost Optimization of PV RecyclingOptimization of PV Recycling InfrastructureInfrastructure JunJun--Ki ChoiKi Choi & Vasilis Fthenakis& Vasilis Recycling ­Cost Optimization 1. Where is the optimized location? · Centralized/decentralized collection

66

Tax policy can change the production path: A model of optimal oil extraction in Alaska  

Science Journals Connector (OSTI)

We model the economically optimal dynamic oil production decisions for seven production units (fields) on Alaska's North Slope. We use adjustment cost and discount rate to calibrate the model against historical production data, and use the calibrated model to simulate the impact of tax policy on production rate. We construct field-specific cost functions from average cost data and an estimated inverse production function, which incorporates engineering aspects of oil production into our economic modeling. Producers appear to have approximated dynamic optimality. Consistent with prior research, we find that changing the tax rate alone does not change the economically optimal oil production path, except for marginal fields that may cease production. Contrary to prior research, we find that the structure of tax policy can be designed to affect the economically optimal production path, but at a cost in net social benefit.

Wayne Leighty; C.-Y. Cynthia Lin

2012-01-01T23:59:59.000Z

67

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

68

Integrated Dynamic Simulation for Process Optimization and Control  

E-Print Network [OSTI]

wherever possible ­ Radiative heat transfer ­ Mass balance ­ Boundary layer transport ­ Surface adsorption;Schematics of Polysilicon RT-CVD Reactor MFC gas cylinder heating lamps RTP reactor RTP pumps 1st stage 2nd-level description ­ Reduced-order models to represent high complexity (e.g., reactor fluid dynamics, heat transfer

Rubloff, Gary W.

69

Inverse modeling of large-scale spatially distributed vadose zone properties using global optimization  

E-Print Network [OSTI]

optimization Jasper A. Vrugt Institute for Biodiversity and Ecosystem Dynamics, Faculty of Science, University

Vrugt, Jasper A.

70

Polymer Reaction Engineering Laboratory -University of Maryland at College Park Reactor Dynamics, Control, Optimization  

E-Print Network [OSTI]

, Control, Optimization Exothermic polymerization reactions in continuous flow reactors may cause complexPolymer Reaction Engineering Laboratory - University of Maryland at College Park Reactor Dynamics nonlinear steady state and transient behaviors. The topic of reactor dynamics has been the subject

Rubloff, Gary W.

71

Reactor Modeling and Recipe Optimization of Polyether Polyol Processes  

E-Print Network [OSTI]

Reactor Modeling and Recipe Optimization of Polyether Polyol Processes Spring 2013 EWO Meeting Yisu.M. Wassick. Reactor Modeling and Recipe Optimization of Polyether Polyol Processes: Polypropylene Glycol Project timeline Development of systematic optimization methods of batch processes Nov. 2009 - Dec. 2011

Grossmann, Ignacio E.

72

Finding Benefits by Modeling and Optimizing Steam and Power Systems  

E-Print Network [OSTI]

A site-wide steam modeling and optimization program (Visual MESA) was implemented at the INEOS Chocolate Bayou site. This program optimizes steam production, compressor turbine extraction, pump operation (turbine/motor) operation, as well...

Jones, B.; Nelson, D.

2007-01-01T23:59:59.000Z

73

15.094 Systems Optimization: Models and Computation, Spring 2002  

E-Print Network [OSTI]

A computational and application-oriented introduction to the modeling of large-scale systems in a wide variety of decision-making domains and the optimization of such systems using state-of-the-art optimization software. ...

Freund, Robert Michael

74

Ergonomic Modelling and Optimization of the Keyboard Arrangement with an Ant Colony Optimization  

E-Print Network [OSTI]

Ergonomic Modelling and Optimization of the Keyboard Arrangement with an Ant Colony Optimization justified the choice of heuristic ergonomic criteria, a mathematical function for the ergonomic eval- uation the arrangement have any alphanumeric logical order nor is it optimized according to a high hit rate or ergonomic

Paris-Sud XI, Université de

75

Adaptive and Dynamic Ant Colony Search Algorithm for Optimal Distribution Systems Reinforcement Strategy  

Science Journals Connector (OSTI)

The metaheuristic technique of Ant Colony Search has been revised here in order to deal with dynamic search optimization problems having a large search space and mixed integer variables. The problem to which it has been applied is an electrical distribution ... Keywords: ant colony search, dynamic optimization problems, electrical distribution systems

S. Favuzza; G. Graditi; E. Riva Sanseverino

2006-02-01T23:59:59.000Z

76

On Using Complex Event Processing for Dynamic Demand Response Optimization in Microgrid  

E-Print Network [OSTI]

On Using Complex Event Processing for Dynamic Demand Response Optimization in Microgrid Qunzhi Zhou is a key benefit of Smart Grids. However, existing demand response optimization (DR) programs fail. Demand response optimization (DR) is a cornerstone com- ponent of Smart Grids, and deals with managing

Prasanna, Viktor K.

77

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture  

E-Print Network [OSTI]

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture Stefano Accepted 26 September 2013 Available online 9 October 2013 Keywords: Optimization Photosynthesis Soil moisture Stomatal conductance Transpiration a b s t r a c t Optimization theories explain a variety

Katul, Gabriel

78

Multiobjective Dynamic Optimization of an Industrial Nylon 6 Semibatch Reactor Using Genetic Algorithm  

E-Print Network [OSTI]

Multiobjective Dynamic Optimization of an Industrial Nylon 6 Semibatch Reactor Using Genetic optimization, nylon 6, genetic algorithm, polymer reactor, polymerization, Pareto sets trial nylon 6 reactor for use in the optimal design and operation of these reactors. Some stud- ies4­9 have already been

Coello, Carlos A. Coello

79

Model Identification for Optimal Diesel Emissions Control  

SciTech Connect (OSTI)

In this paper we develop a model based con- troller for diesel emission reduction using system identification methods. Specifically, our method minimizes the downstream readings from a production NOx sensor while injecting a minimal amount of urea upstream. Based on the linear quadratic estimator we derive the closed form solution to a cost function that accounts for the case some of the system inputs are not controllable. Our cost function can also be tuned to trade-off between input usage and output optimization. Our approach performs better than a production controller in simulation. Our NOx conversion efficiency was 92.7% while the production controller achieved 92.4%. For NH3 conversion, our efficiency was 98.7% compared to 88.5% for the production controller.

Stevens, Andrew J.; Sun, Yannan; Song, Xiaobo; Parker, Gordon

2013-06-20T23:59:59.000Z

80

RISK SENSITIVE CONTROL AND AN OPTIMAL INVESTMENT MODEL (II)  

E-Print Network [OSTI]

RISK SENSITIVE CONTROL AND AN OPTIMAL INVESTMENT MODEL (II) W. H. Fleming1 and S. J. Sheu2 Brown University and Academia Sinica Abstract. We consider an optimal investment problem proposed by Bielecki and Pliska. The goal of the investment problem is to optimize the long term growth of expected utility

Sheu, Shuenn-Jyi

Note: This page contains sample records for the topic "dynamic optimization model" 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

Numerica: a Modeling Language for Global Optimization Pascal Van Hentenryck  

E-Print Network [OSTI]

equilibrium problems, and design problems (e.g., nu­ clear reactor design). The field of global optimizationNumerica: a Modeling Language for Global Optimization Pascal Van Hentenryck Brown University Box or to optimize a nonlinear function subject to nonlinear constraints. This includes appli­ cations

Neumaier, Arnold

82

Optimizing the dynamic range extension of a radiochromic film dosimetry system  

SciTech Connect (OSTI)

The authors present a radiochromic film dosimetry protocol for a multicolor channel radiochromic film dosimetry system consisting of the external beam therapy (EBT) model GAFCHROMIC film and the Epson Expression 1680 flat-bed document scanner. Instead of extracting only the red color channel, the authors are using all three color channels in the absorption spectrum of the EBT film to extend the dynamic dose range of the radiochromic film dosimetry system. By optimizing the dose range for each color channel, they obtained a system that has both precision and accuracy below 1.5%, and the optimized ranges are 0-4 Gy for the red channel, 4-50 Gy for the green channel, and above 50 Gy for the blue channel.

Devic, Slobodan; Tomic, Nada; Soares, Christopher G.; Podgorsak, Ervin B. [Medical Physics Department, McGill University Health Centre, Montreal, Quebec H3G 1A4 (Canada); Department of Radiation Oncology, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2 (Canada); Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Medical Physics Department, McGill University Health Centre, Montreal, Quebec H3G 1A4 (Canada)

2009-02-15T23:59:59.000Z

83

Applying the Battery Ownership Model in Pursuit of Optimal Battery...  

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

Ownership Model in Pursuit of Optimal Battery Use Strategies 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer...

84

Stochastic Modeling of a Power-Managed System: Construction and Optimization  

E-Print Network [OSTI]

1 Stochastic Modeling of a Power-Managed System: Construction and Optimization Qinru Qiu, Qing Wu of a power-managed electronic system. We formulate the problem of system-level power management-digital components. Dynamic power management ­ which refers to a selective shut-off or slow-down of system components

Pedram, Massoud

85

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

86

Sensitivity of Optimal Operation of an Activated Sludge Process Model  

E-Print Network [OSTI]

Sensitivity of Optimal Operation of an Activated Sludge Process Model Antonio Araujo, Simone sensitivity analysis of optimal operation conducted on an activated sludge process model based on the test.[7] applied a systematic procedure for control structure design of an activated sludge process

Skogestad, Sigurd

87

Utility system integration and optimization models for nuclear power management  

E-Print Network [OSTI]

A nuclear power management model suitable for nuclear utility systems optimization has been developed for use in multi-reactor fuel management planning over periods of up to ten years. The overall utility planning model ...

Deaton, Paul Ferris

1973-01-01T23:59:59.000Z

88

Local energy management through mathematical modeling and optimization  

E-Print Network [OSTI]

(cont.) Extensions to the core TOTEM model include a demand charge model, used for making daily optimal control decisions when the electric bill includes a charge based on the monthly maximum power draw. The problem of ...

Craft David (David Loren), 1973-

2004-01-01T23:59:59.000Z

89

DYNAMIC EMBEDDED OPTIMIZATION AND SHOOTING METHODS FOR POWER  

E-Print Network [OSTI]

example of hybrid systems, with in- teractions between continuous dynamics and discrete events playing

90

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

91

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

92

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

93

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

94

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

95

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect (OSTI)

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

96

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

97

Dynamical Arrest, Structural Disorder, and Optimization of Organic Photovoltaic Devices  

SciTech Connect (OSTI)

This project describes fundamental experimental and theoretical work that relates to charge separation and migration in the solid, heterogeneous or aggregated state. Marcus theory assumes a system in equilibrium with all possible solvent (dipolar) configurations, with rapid interconversion among these on the ET timescale. This project has addressed the more general situation where the medium is at least partially frozen on the ET timescale, i.e. under conditions of dynamical arrest. The approach combined theory and experiment and includes: (1) Computer simulations of model systems, (2) Development of analytical procedures consistent with computer experiment and (3) Experimental studies and testing of the formal theories on this data. Electron transfer processes are unique as a consequence of the close connection between kinetics, spectroscopy and theory, which is an essential component of this work.

Gould, Ian; Dmitry, Matyushov

2014-09-11T23:59:59.000Z

98

Study on optimization model of energy collection efficiency and its power generation benefit evaluation of landfill gas  

Science Journals Connector (OSTI)

An optimization model for joint biogas energy collection efficiency that targets the prediction model for landfill gas output dynamics and the optimization model for gas well output has been established. The model was used to comprehensively analyze and evaluate the collection efficiency of a landfill gas well together with the long-term monitoring the gas output of the gas well within Chenjiachong Landfill. The collection efficiency increased by more than 50% than the original collection of landfill biogas and the power generation efficiency increased more than two times after the reservoir area of the landfill was optimized and regulated.

Xue Qiang

2013-01-01T23:59:59.000Z

99

Optimized nuclear and solar dynamic organic Rankine cycles for Space Station applications  

E-Print Network [OSTI]

OPTIMIZED NUCLEAR AND SOLAR DYNAMIC ORGANIC RANKINE CYCLES FOR SPACE STATION A. PPLICATIONS A Thesis by DANA LEN EUBANKS Submitted to the Office of Graduate Studies of Texas AkM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1988 Major Subject: Nuclear Engineering OPTIMIZED NUCLEAR AND SOLAR DYNAMIC ORGANIC RANKINE CYCLES FOR SPACE STATION APPLICATIONS A Thesis by DANA LEN EUBANKS Approved as to style and content by: Frederick R...

Eubanks, Dana Len

2012-06-07T23:59:59.000Z

100

Optimization Models for Optimal Investment, Drilling, and Water Management in Shale Gas Supply Chains  

Science Journals Connector (OSTI)

Abstract This paper provides an overview of recent optimization models for shale gas production. We first describe a new mixed-integer optimization model for the design of shale gas infrastructures. It is aimed at optimizing the number of wells to drill, size and location of new gas processing plants, section and length of pipelines for gathering raw gas, delivering dry gas and natural gas liquids, power of gas compressors, and planning of freshwater consumption for well drilling and fracturing. We also describe a detailed operational mixed-integer linear model to optimize life cycle water use for well pads. The objective of the model is to determine the fracturing schedule that minimizes costs for freshwater consumption, transportation, treatment, storage, and disposal.

Ignacio E. Grossmann; Diego C. Cafaro; Linlin Yang

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic optimization model" 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

Computation of optimal policies in replacement models  

Science Journals Connector (OSTI)

......the level of metal particles in an engine oil, or a vibration monitoring...Optimal replacement times--a general set-up J. Appl. Prob. 23...Proportional hazards analysis of diesel engine failure data. Quality & Reliab......

V. MAKIS; A. K. S. JARDINE

1991-01-01T23:59:59.000Z

102

Energy and cost optimization in industrial models  

Science Journals Connector (OSTI)

A program for Linear Energy Optimization (LEO...) which was used to investigate thermodynamical and technical options of reducing the energy-consumption of industrialized countries is extended to handle the cost ...

H. -M. Groscurth; R. Kümmel

1990-01-01T23:59:59.000Z

103

Hybrid fuzzy and optimal modeling for water quality evaluation  

E-Print Network [OSTI]

Hybrid fuzzy and optimal modeling for water quality evaluation Dong Wang, 1 Vijay P. Singh, 2 and Yuansheng Zhu 3 Received 1 September 2006; revised 16 December 2006; accepted 19 January 2007; published 8 May 2007. [1] Water quality evaluation... evaluation issues. In addition, the proposed models are flexible and adaptable for diagnosing the eutrophic status. Citation: Wang, D., V. P. Singh, and Y. Zhu (2007), Hybrid fuzzy and optimal modeling for water quality evaluation, Water Resour. Res., 43, W...

Wang, Dong; Singh, Vijay P.; Zhu, Yuansheng

2007-05-08T23:59:59.000Z

104

Finding Benefits by Modeling and Optimizing Steam and Power Systems  

E-Print Network [OSTI]

A site-wide steam modeling and optimization program (Visual Mesa) was implemented at the Bayou Cogen plant in Bayport, Texas in 1997 and has been in use continuously since that time. This program optimizes steam production among four cogen units...

Harper, C.; Nelson, D. A.

2008-01-01T23:59:59.000Z

105

Very Large System Dynamics Models - Lessons Learned  

SciTech Connect (OSTI)

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

106

A new hybrid model optimized by an intelligent optimization algorithm for wind speed forecasting  

Science Journals Connector (OSTI)

Abstract Forecasting the wind speed is indispensable in wind-related engineering studies and is important in the management of wind farms. As a technique essential for the future of clean energy systems, reducing the forecasting errors related to wind speed has always been an important research subject. In this paper, an optimized hybrid method based on the Autoregressive Integrated Moving Average (ARIMA) and Kalman filter is proposed to forecast the daily mean wind speed in western China. This approach employs Particle Swarm Optimization (PSO) as an intelligent optimization algorithm to optimize the parameters of the ARIMA model, which develops a hybrid model that is best adapted to the data set, increasing the fitting accuracy and avoiding over-fitting. The proposed method is subsequently examined on the wind farms of western China, where the proposed hybrid model is shown to perform effectively and steadily.

Zhongyue Su; Jianzhou Wang; Haiyan Lu; Ge Zhao

2014-01-01T23:59:59.000Z

107

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

108

Gain-scheduled `1 -optimal control for boiler-turbine dynamics  

E-Print Network [OSTI]

Gain-scheduled `1 -optimal control for boiler-turbine dynamics with actuator saturation Pang; accepted 2 June 2003 Abstract This paper presents a gain-scheduled approach for boiler-turbine controller the magnitude and rate saturation constraints on actuators. The nonlinear boiler-turbine dynamics is brought

Shamma, Jeff S.

109

Optimal Myopic Sensing and Dynamic Spectrum Access in Cognitive Radio Networks with  

E-Print Network [OSTI]

1 Optimal Myopic Sensing and Dynamic Spectrum Access in Cognitive Radio Networks with Low primary channels that are licensed to primary users. We consider a group of SU's with limited spectrum. Index Terms--Cognitive radios, dynamic spectrum access (DSA), Markov chains, partially observable Markov

Jayaweera, Sudharman K.

110

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/

111

An Optimization Model for Eco-Driving at Signalized Intersection  

E-Print Network [OSTI]

This research develops an optimization model for eco-driving at signalized intersection. In urban areas, signalized intersections are the “hot spots” of air emissions and have significant negative environmental and health impacts. Eco-driving is a...

Chen, Zhi

2013-07-15T23:59:59.000Z

112

Online Modeling in the Process Industry for Energy Optimization  

E-Print Network [OSTI]

"This paper discusses how steady state models are being used in the process industry to perform online energy optimization of steam and electrical systems. It presents process demands commonly found in the processing industry in terms of steam...

Alexander, J.

113

Computation of optimal policies in replacement models  

Science Journals Connector (OSTI)

......in a given replacement cycle, and let Zk be the value of...properties, and the replacement cycles are repeated indefini- tely...Optimal replacement times--a general set-up J. Appl. Prob. 23...Proportional hazards analysis of diesel engine failure data. Quality......

V. MAKIS; A. K. S. JARDINE

1991-01-01T23:59:59.000Z

114

Optimization Online - On the Dynamic Stability of Electricity Markets  

E-Print Network [OSTI]

Jan 31, 2011 ... On the Dynamic Stability of Electricity Markets. Victor M. Zavala (vzavala ***at*** mcs.anl.gov) Mihai Anitescu (anitescu ***at*** mcs.anl.gov).

Victor M. Zavala

2011-01-31T23:59:59.000Z

115

Performance and Optimization of Network Building Evacuation Models  

E-Print Network [OSTI]

Performance and Optimization of Network Building Evacuation Models Andrea Weiss, Dr. Jim Mac/G/C/C queues, a simulation program was used to model two buildings on the Umass Amherst campus: Machmer Hall expedient paths are taken. Research Objectives · Create a realistic model of buildings with large

Mountziaris, T. J.

116

Modeling and Optimizing Ergonomic Activities in Automobile Product Development  

E-Print Network [OSTI]

Modeling and Optimizing Ergonomic Activities in Automobile Product Development João Ferreira Anna.silva@acm.org Abstract We collect ergonomic rules and normative rules considerations for automobile business and modeled these activities with a special UML language created for automobile business, VDML (Vehicle Development Modeling

da Silva, Alberto Rodrigues

117

Multi-objective optimization of GENIE Earth system models  

Science Journals Connector (OSTI)

...Multi-objective optimization of GENIE Earth system models Andrew R. Price 1 * Richard...execution and management of Earth system models (ESMs) capable of simulation...Multiobjective tuning of Grid-enabled Earth system models using a non-dominated sorting...

2009-01-01T23:59:59.000Z

118

Modeling and Multi-objective Optimization of Refinery Hydrogen Network  

Science Journals Connector (OSTI)

The demand of hydrogen in oil refinery is increasing as market forces and environmental legislation, so hydrogen network management is becoming increasingly important in refineries. Most studies focused on single- objective optimization problem for the hydrogen network, but few account for the multi-objective optimization problem. This paper presents a novel approach for modeling and multi-objective optimization for hydrogen network in refineries. An improved multi-objective optimization model is proposed based on the concept of superstructure. The optimization includes minimization of operating cost and minimization of investment cost of equipment. The proposed methodology for the multi-objective optimization of hydrogen network takes into account flow rate constraints, pressure constraints, purity constraints, impurity constraints, payback period, etc. The method considers all the feasible connections and subjects this to mixed-integer nonlinear programming (MINLP). A deterministic optimization method is applied to solve this multi-objective optimization problem. Finally, a real case study is introduced to illustrate the applicability of the approach.

Yunqiang JIAO; Hongye SU; Zuwei LIAO; Weifeng HOU

2011-01-01T23:59:59.000Z

119

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect (OSTI)

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

120

Heterogeneous nuclear reactor models for optimal xenon control  

SciTech Connect (OSTI)

In this study a thermal nuclear reactor is modeled as a two-dimensional lattice of fuel and control rods placed in an infinite-moderator in plane geometry. The two-group diffusion theory approximation is used for neutron transport. Space-time neutron balance equations are written for two groups and reduced to one space-time algebraic equation by using the two-dimensional Fourier transform. This equation is written at all fuel and control rod locations. Iodine-xenon and promethium-samarium dynamic equations are also written at fuel rod locations only. These equations are then linearized about an equilibrium point which is determined from the steady-state form of the original nonlinear system equations. After studying poisonless criticality, with and without control, and the stability of the open-loop system and after checking its controllability, a performance criterion is defined for the xenon-induced spatial flux oscillation problem in the form of a functional to be minimized. Linear-quadratic optimal control theory is then applied to solve the problem.

Gondal, I.A.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic optimization model" 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

New Models Help Optimize Development of Bakken Shale Resources | Department  

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

Models Help Optimize Development of Bakken Shale Resources Models Help Optimize Development of Bakken Shale Resources New Models Help Optimize Development of Bakken Shale Resources February 7, 2012 - 12:00pm Addthis Washington, DC - Exploration and field development in the largest continuous oil play in the lower 48 states, located in North Dakota and eastern Montana, will be guided by new geo-models developed with funding from the Department of Energy's (DOE) Office of Fossil Energy (FE). The three-year project to develop exploration and reservoir models for the Bakken Shale resource play was conducted by the Colorado School of Mines (CSM), through research funded by FE's Oil and Natural Gas Program. A "play" is a shale formation containing significant accumulations of natural gas or oil. The U.S. Geological Survey estimates the Bakken Shale

122

New Models Help Optimize Development of Bakken Shale Resources | Department  

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

New Models Help Optimize Development of Bakken Shale Resources New Models Help Optimize Development of Bakken Shale Resources New Models Help Optimize Development of Bakken Shale Resources February 7, 2012 - 12:00pm Addthis Washington, DC - Exploration and field development in the largest continuous oil play in the lower 48 states, located in North Dakota and eastern Montana, will be guided by new geo-models developed with funding from the Department of Energy's (DOE) Office of Fossil Energy (FE). The three-year project to develop exploration and reservoir models for the Bakken Shale resource play was conducted by the Colorado School of Mines (CSM), through research funded by FE's Oil and Natural Gas Program. A "play" is a shale formation containing significant accumulations of natural gas or oil. The U.S. Geological Survey estimates the Bakken Shale

123

System Modeling, Analysis, and Optimization Methodology for Diesel Exhaust After-treatment Technologies  

E-Print Network [OSTI]

System Modeling, Analysis, and Optimization Methodology for Diesel Exhaust After;System Modeling, Analysis, and Optimization Methodology for Diesel Exhaust After-treatment Technologies, analyzing, and optimizing of complex diesel exhaust after-treatment systems. The methodology presented

de Weck, Olivier L.

124

NETL: Gasification Systems - Model Based Optimal Sensor Network Design for  

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

Model Based Optimal Sensor Network Design for Condition Monitoring Model Based Optimal Sensor Network Design for Condition Monitoring Project Number: FE0005712 General Electric (GE) Global Research is developing an advanced model-based optimal sensor network to monitor the condition of the gasification section in an integrated gasification combined cycle (IGCC) plant. The work builds on model-based controls aimed at enhancing efficiency and operational flexibility through increased automation. Within an overall strategy of employing model-based online monitoring and predictive controls, GE Global Research is extending existing models for the gasifier and radiant syngas cooler to include the effects of degradation and fouling on the sensed variables like temperature etc., and will implement an estimation algorithm to assess the extent of gasifier refractory degradation and radiant syngas cooler fouling. An optimization-based solution will be employed to optimally place the hardware sensors utilized in the estimation algorithm in order to achieve the monitoring requirements at the lowest cost. The performance of the sensor placement algorithm and resulting monitoring solution will be demonstrated through simulations using representative test cases. The overall approach is one of the first to be applicable to condition monitoring of critical components in IGCC plants.

125

Integrating multi-objective optimization with computational fluid dynamics to optimize boiler combustion process of a coal fired power plant  

Science Journals Connector (OSTI)

Abstract The dominant role of electricity generation and environment consideration have placed strong requirements on coal fired power plants, requiring them to improve boiler combustion efficiency and decrease carbon emission. Although neural network based optimization strategies are often applied to improve the coal fired power plant boiler efficiency, they are limited by some combustion related problems such as slagging. Slagging can seriously influence heat transfer rate and decrease the boiler efficiency. In addition, it is difficult to measure slag build-up. The lack of measurement for slagging can restrict conventional neural network based coal fired boiler optimization, because no data can be used to train the neural network. This paper proposes a novel method of integrating non-dominated sorting genetic algorithm (NSGA II) based multi-objective optimization with computational fluid dynamics (CFD) to decrease or even avoid slagging inside a coal fired boiler furnace and improve boiler combustion efficiency. Compared with conventional neural network based boiler optimization methods, the method developed in the work can control and optimize the fields of flue gas properties such as temperature field inside a boiler by adjusting the temperature and velocity of primary and secondary air in coal fired power plant boiler control systems. The temperature in the vicinity of water wall tubes of a boiler can be maintained within the ash melting temperature limit. The incoming ash particles cannot melt and bond to surface of heat transfer equipment of a boiler. So the trend of slagging inside furnace is controlled. Furthermore, the optimized boiler combustion can keep higher heat transfer efficiency than that of the non-optimized boiler combustion. The software is developed to realize the proposed method and obtain the encouraging results through combining ANSYS 14.5, ANSYS Fluent 14.5 and CORBA C++.

Xingrang Liu; R.C. Bansal

2014-01-01T23:59:59.000Z

126

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

127

INDDGO: Integrated Network Decomposition & Dynamic programming for Graph Optimization  

SciTech Connect (OSTI)

It is well-known that dynamic programming algorithms can utilize tree decompositions to provide a way to solve some \\emph{NP}-hard problems on graphs where the complexity is polynomial in the number of nodes and edges in the graph, but exponential in the width of the underlying tree decomposition. However, there has been relatively little computational work done to determine the practical utility of such dynamic programming algorithms. We have developed software to construct tree decompositions using various heuristics and have created a fast, memory-efficient dynamic programming implementation for solving maximum weighted independent set. We describe our software and the algorithms we have implemented, focusing on memory saving techniques for the dynamic programming. We compare the running time and memory usage of our implementation with other techniques for solving maximum weighted independent set, including a commercial integer programming solver and a semi-definite programming solver. Our results indicate that it is possible to solve some instances where the underlying decomposition has width much larger than suggested by the literature. For certain types of problems, our dynamic programming code runs several times faster than these other methods.

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

2012-10-01T23:59:59.000Z

128

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

129

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

130

Dynamic Scheduling of a Parallel Server System in Heavy Traffic with Complete Resource Pooling: Asymptotic Optimality of a  

E-Print Network [OSTI]

as the optimal cost in the Brownian control problem. Short title: Dynamic Scheduling of Parallel Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Scheduling Control and Performance Measures . . . . . . . . . . . . . . . . . . . . . . . . 7Dynamic Scheduling of a Parallel Server System in Heavy Traffic with Complete Resource Pooling

131

"Performance and Optimization of Building Evacuation Models" Andrea Weiss  

E-Print Network [OSTI]

"Performance and Optimization of Building Evacuation Models" Andrea Weiss Faculty Mentor: Dr. James in ensuring safety of individuals inside a building. In order to determine the most efficient paths, models that can be made when representing a building. By breaking the rooms and hallways into smaller sections

Mountziaris, T. J.

132

Multiperiod Multiproduct Advertising Budgeting. Part II: Stochastic Optimization Modeling  

E-Print Network [OSTI]

Multiperiod Multiproduct Advertising Budgeting. Part II: Stochastic Optimization Modeling C for the Multiperiod Multiproduct Advertising Budgeting problem, so that the expected profit of the advertising of standard opti- mization software. The model has been tested for planning a realistic advertising campaign

Beltran-Royo, Cesar

133

Global and Convex Optimization in Modeling Environments ...  

E-Print Network [OSTI]

Aug 12, 2002 ... In this study, a bipolar transistor is modeled by an electrical circuit. .... power, delivered to the radiation resistance Rr, to input electric power.

Administrator

2002-08-16T23:59:59.000Z

134

Optimal economy-based battery degradation management dynamics for fuel-cell plug-in hybrid electric vehicles  

Science Journals Connector (OSTI)

Abstract This work analyses the economical dynamics of an optimized battery degradation management strategy intended for plug-in hybrid electric vehicles (PHEVs) with consideration given to low-cost technologies, such as lead-acid batteries. The optimal management algorithm described herein is based on discrete dynamic programming theory (DDP) and was designed for the purpose of PHEV battery degradation management; its operation relies on simulation models using data obtained experimentally on a physical PHEV platform. These tools are first used to define an optimal management strategy according to the economical weights of PHEV battery degradation and the secondary energy carriers spent to manage its deleterious effects. We then conduct a sensitivity study of the proposed optimization process to the fluctuating economic parameters associated with the fuel and energy costs involved in the degradation management process. Results demonstrate the influence of each parameter on the process's response, including daily total operating costs and expected battery lifetime, as well as establish boundaries for useful application of the method; in addition, they provide a case for the relevance of inexpensive battery technologies, such as lead-acid batteries, for economy-centric PHEV applications where battery degradation is a major concern.

François Martel; Sousso Kelouwani; Yves Dubé; Kodjo Agbossou

2015-01-01T23:59:59.000Z

135

IMPACT OF DYNAMIC VOLTAGE SCALING (DVS) ON CIRCUIT OPTIMIZATION  

E-Print Network [OSTI]

and dynamic power, respectively. Both gate sizing and Dual-VT are design-time techniques, which are applied to the circuit at a fixed voltage. On the other hand, DVS is a run-time technique and implies that the circuit will be operating at a different voltage...

Esquit Hernandez, Carlos A.

2010-01-16T23:59:59.000Z

136

Dynamic Optimization of IA-32 Applications Under DynamoRIO  

E-Print Network [OSTI]

programs statically is diminishing. The advent and increased use of shared libraries, dynamic class loading, and runtime binding means that the compiler has, even with difficult to accurately obtain profiling data, less is known and very accurate profiling data can be obtained. This thesis presents two uses of the Dynamo

Amarasinghe, Saman

137

A joint optimal pricing, rebate value, and lot sizing model  

Science Journals Connector (OSTI)

Delayed incentives in the form of mail-in cash rebates are very popular among manufacturers, and more recently, among retailers. One of the main advantages of rebates is that while they increase demand, a small proportion of consumers redeem them. In this paper, we formulate and solve models for jointly determining the optimal price, rebate face value, and the optimal order quantity for a price and rebate sensitive deterministic demand. The models show that under realistic conditions, offering rebates can have significant pricing and inventory policy implications and can lead to a significant increase in profit.

Moutaz Khouja

2006-01-01T23:59:59.000Z

138

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

139

Modeling emotional dynamics : currency versus field.  

SciTech Connect (OSTI)

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

140

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

Risk-based Multiobjective Optimization Model for Bridge Maintenance Planning  

SciTech Connect (OSTI)

Determining the optimal maintenance plan is essential for successful bridge management. The optimization objectives are defined in the forms of minimizing life-cycle cost and maximizing performance indicators. Previous bridge maintenance models assumed the process of bridge deterioration and the estimate of maintenance cost are deterministic, i.e., known with certainty. This assumption, however, is invalid especially with estimates over a long time horizon of bridge life. In this study, we consider the risks associated with bridge deterioration and maintenance cost in determining the optimal maintenance plan. The decisions variables include the strategic choice of essential maintenance (such as silane treatment and cathodic protection), and the intervals between periodic maintenance. A epsilon-constrained Particle Swarm Optimization algorithm is used to approximate the tradeoff between life-cycle cost and performance indicators. During stochastic search for optimal solutions, Monte-Carlo simulation is used to evaluate the impact of risks on the objective values, at an acceptance level of reliability. The proposed model can facilitate decision makers to select the compromised maintenance plan with a group of alternative choices, each of which leads to a different level of performance and life-cycle cost. A numerical example is used to illustrate the proposed model.

Yang, I-T. [Associate Professor, National Taiwan University of Science and Technology (China); Hsu, Y.-S.

2010-05-21T23:59:59.000Z

142

Dynamic forecasting and adaptation for demand optimization in the smart grid  

Science Journals Connector (OSTI)

The daily peaks and valleys in energy demand create inefficiencies and expense in the operation of the electricity grid. Valley periods force utilities to curtail renewable energy sources such as wind as their unpredictable nature makes it difficult ... Keywords: cross-layer, demand optimization, dynamic adaptation, prediction, smart grid

Eamonn O'Toole, Siobhán Clarke

2012-06-01T23:59:59.000Z

143

Short Paper: On Optimal Sensing and Transmission Strategies for Dynamic Spectrum Access  

E-Print Network [OSTI]

-Before-Talk (LBT) principle, according to which the SU senses the channel before transmission. While this principleShort Paper: On Optimal Sensing and Transmission Strategies for Dynamic Spectrum Access Senhua reduce the secondary transmission opportunities. In this paper, we generalize the packet-level LBT

Liu, Xin

144

Optimization Online - On Ants, Bacteria and Dynamic Environments  

E-Print Network [OSTI]

Dec 2, 2005 ... Then, for the purpose of comparison, a recent model of artificial ... Final results indicate that the SSA collective intelligence is able to cope and ...

Vitorino Ramos

2005-12-02T23:59:59.000Z

145

Predicting and optimization of energy consumption using system dynamics-fuzzy multiple objective programming in world heritage areas  

Science Journals Connector (OSTI)

Energy consumption and efficiency are important in regional low-carbon economic development and environmental protection. This paper provides a system dynamics and fuzzy multi-objective programming integrated approach for the prediction of energy consumption and CO2 emissions at a regional level. First, a general system dynamics model is constructed to analyze an economy-energy system. To deal with the uncertainties and optimize the parameters in the system, a fuzzy multiple objective programming model is used. This decision support model is then applied to predict the energy consumption of a world heritage area in China during 2010–2020. The results reveal that the energy consumption and CO2 emissions increase dramatically with rapid economic growth. In the scenario herein considered, which is based on the proposed optimization model, a 19.32% reduction was found in the energy intensity decreases from 0.88 tce/104 RMB to 0.71 tce/104 RMB, and a 23.26% reduction in the CO2 emission intensity, from 2.15 t/104 RMB to 1.65 t/104 RMB. Policy suggestions such as adjusting the industrial structure, enhancing local hydro-power and renewable energy and increasing investment in energy technology and efficiency are indicated for the promotion of a low-carbon oriented economy in world heritage areas.

Zhibin Wu; Jiuping Xu

2013-01-01T23:59:59.000Z

146

Stochastic Modeling of a Power-Managed System: Construction and Optimization Qinru Qiu, Qing Wu and Massoud Pedram  

E-Print Network [OSTI]

1 Stochastic Modeling of a Power-Managed System: Construction and Optimization Qinru Qiu, Qing Wu of a power-managed electronic system. We formulate the problem of system-level power management-digital components. Dynamic power management ­ which refers to selective shut-off or slow-down of system components

Qiu, Qinru

147

Modeling of Reactor Kinetics and Dynamics  

SciTech Connect (OSTI)

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

148

Modeling joint friction in structural dynamics.  

SciTech Connect (OSTI)

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

149

Stochastic dynamic optimization of consumption and the induced price elasticity of demand in smart grids .  

E-Print Network [OSTI]

??This thesis presents a mathematical model of consumer behavior in response to stochastically-varying electricity prices, and a characterization of price-elasticity of demand created by optimal… (more)

Faghih, Ali

2011-01-01T23:59:59.000Z

150

Stochastic dynamic optimization of consumption and the induced price elasticity of demand in smart grids  

E-Print Network [OSTI]

This thesis presents a mathematical model of consumer behavior in response to stochastically-varying electricity prices, and a characterization of price-elasticity of demand created by optimal utilization of storage and ...

Faghih, Ali

2011-01-01T23:59:59.000Z

151

Managing Approximate Models in Evolutionary Aerodynamic Design Optimization  

E-Print Network [OSTI]

Managing Approximate Models in Evolutionary Aerodynamic Design Optimization Yaochu Jin yaochu jin­ mization problems that are discontinuous, multi­modal and multi­objective [1, 2]. Aerodynamic structural to high complexity of the aerodynamic analysis and large number of evaluations needed in the evolutionary

Coello, Carlos A. Coello

152

The PDB_REDO server for macromolecular structure model optimization  

Science Journals Connector (OSTI)

The PDB_REDO pipeline aims to improve macromolecular structures by optimizing the crystallographic refinement parameters and performing partial model building. Here, algorithms are presented that allowed a web-server implementation of PDB_REDO, and the first user results are discussed.

Joosten, R.P.

2014-05-30T23:59:59.000Z

153

An Operational Model for Optimal NonDispatchable Demand Response  

E-Print Network [OSTI]

An Operational Model for Optimal NonDispatchable Demand Response for Continuous PowerintensiveFACTS, $ Demand Response Energy Storage HVDC Industrial Customer PEV Renewable Energy Source: U.S.-Canada Power: To balance supply and demand of a power system, one can manipulate both: supply and demand demand response

Grossmann, Ignacio E.

154

Modeling and Computational Strategies for Optimal Development Planning of Offshore  

E-Print Network [OSTI]

1 Modeling and Computational Strategies for Optimal Development Planning of Offshore Oilfields for offshore oil and gas fields as a basis to include the generic fiscal rules with ringfencing provisions-integer programming. 1 Introduction Offshore oil and gas field development planning has received significant attention

Grossmann, Ignacio E.

155

Utility functions and optimal investment in non-dominated models  

E-Print Network [OSTI]

Utility functions and optimal investment in non-dominated models Laurent DENIS Département de@univ-evry.fr Abstract: In this paper, we provide a framework in which we can set the problem of maximization of utility establish a duality theory for robust utility maximization in this framework. AMS 2000 subject

Paris-Sud XI, Université de

156

Operational Model for C3 Feedstock Optimization on a  

E-Print Network [OSTI]

Chemical and refinery grade feedstocks with different prices and propylene purities. Best operationOperational Model for C3 Feedstock Optimization on a Polypropylene Production Facility Pablo A Polypropylene production facility Chemical and refinery grade feedstocks with different prices and propylene

Grossmann, Ignacio E.

157

Extended Lagrangian Born-Oppenheimer molecular dynamics in the limit of vanishing self-consistent field optimization  

SciTech Connect (OSTI)

We present an efficient general approach to first principles molecular dynamics simulations based on extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] in the limit of vanishing self-consistent field optimization. The reduction of the optimization requirement reduces the computational cost to a minimum, but without causing any significant loss of accuracy or long-term energy drift. The optimization-free first principles molecular dynamics requires only one single diagonalization per time step, but is still able to provide trajectories at the same level of accuracy as “exact,” fully converged, Born-Oppenheimer molecular dynamics simulations. The optimization-free limit of extended Lagrangian Born-Oppenheimer molecular dynamics therefore represents an ideal starting point for robust and efficient first principles quantum mechanical molecular dynamics simulations.

Souvatzis, Petros, E-mail: petros.souvatsiz@fysik.uu.se [Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Box 516, SE-75120, Uppsala (Sweden)] [Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Box 516, SE-75120, Uppsala (Sweden); Niklasson, Anders M. N., E-mail: amn@lanl.gov [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-12-07T23:59:59.000Z

158

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

159

Design method of dynamical decoupling sequences integrated with optimal control theory  

E-Print Network [OSTI]

A method for synthesizing dynamical decoupling (DD) sequences is presented, which can tailor these sequences to a given set of qubits, environments, instruments, and available resources using partial information of the system. The key concept behind the generation of the DD sequences involves not only extricating the strong dependence on the coupling strengths according to the "optimal control," but also exploiting the "refocus" technique used conventionally to obtain DD sequences. The concept is a generalized one that integrates optimal control and designing of DD sequences.

Yutaka Tabuchi; Masahiro Kitagawa

2012-08-26T23:59:59.000Z

160

The dynamic radiation environment assimilation model (DREAM)  

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

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

162

DYNAMICAL MODELING OF GALAXY MERGERS USING IDENTIKIT  

SciTech Connect (OSTI)

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

163

Simulation Models to Optimize the Energy Consumption of Buildings  

E-Print Network [OSTI]

Page 1 of paper submitted to ICEBO 2008 Berlin SIMULATION MODELS TO OPTIMIZE THE ENERGY CONSUMPTION OF BUILDINGS Sebastian Burhenne Fraunhofer-Institute for Solar Energy Systems Freiburg, Germany Dirk Jacob Fraunhofer...-Institute for Solar Energy Systems Freiburg, Germany ABSTRACT In practice, building operation systems are only adjusted during commissioning. This is done manually and leads to failure-free but often inefficient operation. This work deals...

Burhenne, S.; Jacob, D.

164

Life Cycle Optimization of Automobile Replacement:? Model and Application  

Science Journals Connector (OSTI)

Life Cycle Optimization of Automobile Replacement:? Model and Application ... Moreover, manufacturers have been exploring new propulsion systems and fuels, such as hybrid electric vehicles and hydrogen fuel cell vehicles. ... The catalytic activity of samples taken from an oxidation catalyst mounted on diesel-driven automobiles and aged under road conditions was recovered to a significant extent by washing with a dilute solution of citric acid. ...

Hyung Chul Kim; Gregory A. Keoleian; Darby E. Grande; James C. Bean

2003-11-01T23:59:59.000Z

165

Hour-by-Hour Cost Modeling of Optimized Central Wind-Based Water...  

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

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

166

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

167

Performance monitoring for new phase dynamic optimization of instruction dispatch cluster configuration  

DOE Patents [OSTI]

In a processor having multiple clusters which operate in parallel, the number of clusters in use can be varied dynamically. At the start of each program phase, the configuration option for an interval is run to determine the optimal configuration, which is used until the next phase change is detected. The optimum instruction interval is determined by starting with a minimum interval and doubling it until a low stability factor is reached.

Balasubramonian, Rajeev (Sandy, UT); Dwarkadas, Sandhya (Rochester, NY); Albonesi, David (Ithaca, NY)

2012-01-24T23:59:59.000Z

168

Radiation field modeling and optimization of a compact and modular  

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

Radiation field modeling and optimization of a compact and modular Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Title Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Publication Type Journal Article Year of Publication 2013 Authors Zazueta, Ana Luisa Loo, Hugo Destaillats, and Gianluca Li Puma Journal Chemical Engineering Journal Volume 217 Pagination 475-485 Date Published 02/01/2013 Abstract The radiation field in a multi-plate photocatalytic reactor (MPPR) for air or water purification was modeled and optimized using a Monte Carlo stochastic method. The MPPR consists of parallel photocatalytic plates irradiated by cylindrical UV lamps orthogonal to the plates. The photocatalyst titanium dioxide (TiO2) is supported on the plates as a thin film. The photoreactor design is compact and offers a large irradiated photocatalytic surface area, a high degree of photon utilization, low pressure drop and a modular design which can facilitate scale-up. These features are desirable for the decontamination of indoor air in ventilation ducts or for water detoxification. The Monte Carlo method was applied to determine three dimensionless reactor performance parameters: the photon absorption efficiency (Φ), the uniformity of the distribution of the dimensionless radiation intensity (η) and the overall photonic efficiency (Φ). The emission of photons from the light sources was simulated by the extensive source with superficial emission (ESSE) model. Simulations were performed by varying the catalyst reflectivity albedo, the number and the diameter of lamps, and the dimensions and spacing of the photocatalytic plates. Optimal design for a basic reactor module with one lamp was accomplished for lamp-diameter-to-plate-height ratio (β) of 0.7, while the plate-spacing-to-plate-height ratio (α) was correlated by [αoptimum = 0.191 β2 - 0.5597 β + 0.3854]. A multilamp arrangement leads to a feasible increase in the size and number of the plates and the irradiated photocatalytic surface area. The optimum design was validated by measuring the apparent quantum yield of the oxidation of toluene (7 ppmv) in a humidified air stream using immobilized TiO2 (Degussa P25). Experiments performed varying the geometrical parameter α correlated well with the model calculations, with maximum apparent quantum yield for α = 0.137. The results are directly transferable to the treatment of water by photocatalysis.

169

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

170

Renewable Energy Sources Optimization: A Micro-Grid Model Design  

Science Journals Connector (OSTI)

Abstract This paper analyzes the possibility to develop the simple micro-grid model in optimizing the utilization of local renewable energy for on-grid area. The proposed micro-grid model integrates the power plants driven by renewable energy sources employing micro hydro (MHP) and photovoltaic system (PV) which is connected to grid system. This model is analyzed using HOMER and MATLAB software. Based on the load profiles and the availability of water resources, the HOMER simulates the proposed micro-grid model with three options of MHP capacity. The simulation results show that the micro-grid model with the largest capacity MHP produced the lowest energy cost, greatest reduction of CO2 emission, and largest fraction of renewable energy. However, these result required the expensive initial capital cost. In addition, the PV power generation was always recommended with a minimum capacity. Hence, MATLAB results show the performances of the power plants with renewable energy sources were used maximally.

R. Nazir; H.D. Laksono; E.P. Waldi; E. Ekaputra; P. Coveria

2014-01-01T23:59:59.000Z

171

COAL: a generic modelling and prototyping framework for convex optimization problems of variational image analysis  

Science Journals Connector (OSTI)

We present the Convex Optimization Algorithms Library COAL, a flexible C++framework for modelling and solving convex optimization problems in connection with variational problems of image analysis. COAL connects solver implementations with specific models ... Keywords: convex optimization, image processing, sparse large-scale programming, variational modelling

Dirk Breitenreicher; Jan Lellmann; Christoph Schnörr

2013-10-01T23:59:59.000Z

172

An Optimization Approach for Effective Formalized fUML Model Checking  

E-Print Network [OSTI]

An Optimization Approach for Effective Formalized fUML Model Checking Islam Abdelhalim, Steve that makes use of a restricted CSP model (because it follows certain formalization rules) to optimize; the first one provides optimization advice to the modeller, while the second one au- tomatically applies

Doran, Simon J.

173

DYNAMIC RIDE-SHARING AND OPTIMAL FLEET SIZING FOR A SYSTEM OF1 SHARED AUTONOMOUS VEHICLES2  

E-Print Network [OSTI]

DYNAMIC RIDE-SHARING AND OPTIMAL FLEET SIZING FOR A SYSTEM OF1 SHARED AUTONOMOUS VEHICLES2 3 4 and for publication in Transportation21 22 23 ABSTRACT24 25 Shared autonomous (fully-automated) vehicles (SAVs

Kockelman, Kara M.

174

With faster processors and better numerical techniques, computational fluid dynamics (CFD) tools have revolutionized engineering design and optimization--  

E-Print Network [OSTI]

With faster processors and better numerical techniques, computational fluid dynamics (CFD) tools have revolutionized engineering design and optimization-- limiting expensive experimentation and Engineering Division (GED) at Southwest Research Institute® (SwRI®) has extensive experience and capabilities

Chapman, Clark R.

175

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"

176

Optimal investment, consumption and proportional reinsurance under model uncertainty  

Science Journals Connector (OSTI)

Abstract This paper considers the optimal investment, consumption and proportional reinsurance strategies for an insurer under model uncertainty. The surplus process of the insurer before investment and consumption is assumed to be a general jump–diffusion process. The financial market consists of one risk-free asset and one risky asset whose price process is also a general jump–diffusion process. We transform the problem equivalently into a two-person zero-sum forward–backward stochastic differential game driven by two-dimensional Lévy noises. The maximum principles for a general form of this game are established to solve our problem. Some special interesting cases are studied by using Malliavin calculus so as to give explicit expressions of the optimal strategies.

Xingchun Peng; Fenge Chen; Yijun Hu

2014-01-01T23:59:59.000Z

177

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

178

The Trucking Sector Optimization Model: A tool for predicting carrier and shipper responses to policies aiming to reduce GHG emissions  

Science Journals Connector (OSTI)

Abstract In response to the growing Climate Change problem, governments around the world are seeking to reduce the greenhouse gas (GHG) emissions of trucking. The Trucking Sector Optimization (TSO) model is introduced as a tool for studying the decisions that shippers and carriers make throughout time (focusing on investments in Fuel Saving Technologies), and for evaluating their impact on life-cycle GHG emissions. A case study of fuel taxation in California is used to highlight the importance of (1) modeling the trucking sector comprehensively, (2) modeling the dynamics of the stock of vehicles, and (3) modeling different sources of emissions.

Sebastian E. Guerrero; Samer M. Madanat; Robert C. Leachman

2013-01-01T23:59:59.000Z

179

Optimal dynamics for quantum-state and entanglement transfer through homogeneous quantum systems  

SciTech Connect (OSTI)

The capability of faithfully transmit quantum states and entanglement through quantum channels is one of the key requirements for the development of quantum devices. Different solutions have been proposed to accomplish such a challenging task, which, however, require either an ad hoc engineering of the internal interactions of the physical system acting as the channel or specific initialization procedures. Here we show that optimal dynamics for efficient quantum-state and entanglement transfer can be attained in generic quantum systems with homogeneous interactions by tuning the coupling between the system and the two attached qubits. We devise a general procedure to determine the optimal coupling, and we explicitly implement it in the case of a channel consisting of a spin-(1/2)XY chain. The quality of quantum-state and entanglement transfer is found to be very good and, remarkably, almost independent of the channel length.

Banchi, L. [Dipartimento di Fisica e Astronomia, Universita di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Apollaro, T. J. G. [Dipartimento di Fisica e Astronomia, Universita di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Istituto dei Sistemi Complessi, C.N.R., via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Cuccoli, A. [Dipartimento di Fisica e Astronomia, Universita di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); INFN, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Vaia, R. [Istituto dei Sistemi Complessi, C.N.R., via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Verrucchi, P. [Istituto dei Sistemi Complessi, C.N.R., via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Dipartimento di Fisica e Astronomia, Universita di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); INFN, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy)

2010-11-15T23:59:59.000Z

180

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

Evaluating and developing parameter optimization and uncertainty analysis methods for a computationally intensive distributed hydrological model  

E-Print Network [OSTI]

This study focuses on developing and evaluating efficient and effective parameter calibration and uncertainty methods for hydrologic modeling. Five single objective optimization algorithms and six multi-objective optimization algorithms were tested...

Zhang, Xuesong

2009-05-15T23:59:59.000Z

182

Toward a mechanistic modeling of nitrogen limitation on vegetation dynamics  

SciTech Connect (OSTI)

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

183

Dynamical symmetry breaking with optimal control: reducing the number of pieces  

E-Print Network [OSTI]

We analyse the production of defects during the dynamical crossing of a mean-field phase transition with a real order parameter. When the parameter that brings the system across the critical point changes in time according to a power-law schedule, we recover the predictions dictated by the well-known Kibble-Zurek theory. For a fixed duration of the evolution, we show that the average number of defects can be drastically reduced for a very large but finite system, by optimising the time dependence of the driving using optimal control techniques. Furthermore, the optimised protocol is robust against small fluctuations.

Matthew J. M. Power; Gabriele De Chiara

2014-04-01T23:59:59.000Z

184

Modeling and design optimization of switched reluctance machine by boundary element analysis and simulation  

SciTech Connect (OSTI)

Nonlinear boundary element analysis provides a more accurate and detailing tool for the design of switched reluctance machines, than the conventional equivalent-circuit methods. Design optimization through more detailed analysis and simulation can reduce development and prototyping costs and time to market. Firstly, magnetic field modeling of an industrial switched reluctance machine by boundary element method is reported in this paper. Secondly, performance prediction and dynamic simulation of motor and control design are presented. Thirdly, magnetic forces that cause noise and vibration are studied, to include the effects of motor and control design variations on noise in the design process. Testing of the motor in NEMA 215-Frame size is carried out to verify the accuracy of modeling and simulation.

Tang, Y.; Kline, J.A. Sr. [Emerson Motor Technology Center, St. Louis, MO (United States). U.S. Electrical Motors Div.] [Emerson Motor Technology Center, St. Louis, MO (United States). U.S. Electrical Motors Div.

1996-12-01T23:59:59.000Z

185

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

186

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

187

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

SciTech Connect (OSTI)

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

188

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

SciTech Connect (OSTI)

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

189

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

190

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

191

A dynamic model for the Lagrangian stochastic dispersion coefficient  

SciTech Connect (OSTI)

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

192

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

193

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

194

Test cell modeling and optimization for FPD-II  

SciTech Connect (OSTI)

The Fusion Power Demonstration, Configuration II (FPD-II), will ba a DT burning tandem mirror facility with thermal barriers, designed as the next step engineering test reactor (ETR) to follow the tandem mirror ignition test machines. Current plans call for FPD-II to be a multi-purpose device. For approximately the first half of its lifetime, it will operate as a high-Q ignition machine designed to reach or exceed engineering break-even and to demonstrate the technological feasibility of tandem mirror fusion. The second half of its operation will focus on the evaluation of candidate reactor blanket designs using a neutral beam driven test cell inserted at the midplane of the 90 m long cell. This machine called FPD-II+T, uses an insert configuration similar to that used in the MFTF-..cap alpha..+T study. The modeling and optimization of FPD-II+T are the topic of the present paper.

Haney, S.W.; Fenstermacher, M.E.

1985-04-10T23:59:59.000Z

195

Optimal consumption in a growth model with the Cobb-Douglas production function  

E-Print Network [OSTI]

Optimal consumption in a growth model with the Cobb-Douglas production function Hiroaki Morimoto Management, The Chinese University of Hong Kong, Shatin, Hong Kong Abstract An optimal consumption problem, and a synthesis of the optimal consumption policy is presented in the feedback form. Key words. Economic growth

196

Optimization of the structural Gabor functions in a homogeneous velocity model  

E-Print Network [OSTI]

Optimization of the structural Gabor functions in a homogeneous velocity model for a zero-o#11;set functions should be optimized, and the Gabor functions should form a frame. We present a simple attempt functions and the space{wavenumber lattice of their central points are optimized analytically

Cerveny, Vlastislav

197

Chemical reactor models of optimal digestion efficiency with constant foraging costs  

E-Print Network [OSTI]

Chemical reactor models of optimal digestion efficiency with constant foraging costs J. David Logan-batch reactor or plug flow reactor. Specifically, we determine the residence time that optimizes the average net , Anthony Joern , & William Wolesensky January 24, 2003 Abstract We develop quantitative optimization

Logan, David

198

Macroscopic Mechanistic Modeling and Optimization of a Self-Initiated High-Temperature Polymerization Reactor  

E-Print Network [OSTI]

and optimization study of a batch polymerization reactor in which self-initiated free-radical poly- merization of n to calculate an optimal batch-reactor temperature profile that yields an end-batch polymer product with desiredMacroscopic Mechanistic Modeling and Optimization of a Self-Initiated High

Rappe, Andrew M.

199

Economic Nonlinear Model Predictive Control for the Optimization of Gas Pipeline Networks  

E-Print Network [OSTI]

Economic Nonlinear Model Predictive Control for the Optimization of Gas Pipeline Networks EWO University Oct 12, 2011 Ajit Gopalakrishnan (CMU) Economic NMPC for gas pipeline optimization Oct 12, 2011 1 Gopalakrishnan (CMU) Economic NMPC for gas pipeline optimization Oct 12, 2011 4 / 24 #12;Natural Gas Industry

Grossmann, Ignacio E.

200

Optimization of BEM-based Cooling Channels Injection Moulding Using Model Reduction  

E-Print Network [OSTI]

of optimization variables). However, thermal models involved in the numerical modelling in injection mouldingOptimization of BEM-based Cooling Channels Injection Moulding Using Model Reduction N. Pirc1 , F: Today, around 30% of manufactured plastic goods rely on injection moulding. The cooling time can

Mongeau, Marcel

Note: This page contains sample records for the topic "dynamic optimization model" 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

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic Controlled Variable Selection  

E-Print Network [OSTI]

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no structure that leads to optimal economic operation, while promptly rejecting disturbances at lower layers

Skogestad, Sigurd

202

Heliostat Field Optimization: A New Computationally Efficient Model and Biomimetic Layout  

E-Print Network [OSTI]

Heliostat Field Optimization: A New Computationally Efficient Model and Biomimetic Layout Corey J for heliostat field layout optimization are introduced. The model, described and validated herein, includes & blocking, aberration and atmospheric attenuation. The model is based on a discretization of the heliostats

203

20.18 Optimization Problems in Air Pollution Modeling Ivan Dimov, and Zahari Zlatev  

E-Print Network [OSTI]

20.18 Optimization Problems in Air Pollution Modeling Ivan Dimov, and Zahari Zlatev ABSTRACT. The appearance of optimization problems in the field of air pollution modeling and their importance arising in air pollution modeling will be considered. We shall present a review of some approaches

Dimov, Ivan

204

The d-Level Nested Logit Model: Assortment and Price Optimization Problems  

E-Print Network [OSTI]

The d-Level Nested Logit Model: Assortment and Price Optimization Problems Guang Li Paat, 2013 @ 2:27pm Abstract We provide a new formulation of the d-level nested logit model using a tree the optimal assort- ment. For a d-level nested logit model with n products, the running time of the algorithm

Topaloglu, Huseyin

205

A Novel Adaptive Web Service Selection Algorithm Based on Ant Colony Optimization for Dynamic Web Service Composition  

Science Journals Connector (OSTI)

Trust degree and quality of service are nonfunctional properties of component service. In dynamic web service composition, trust degree is variable. ... paper we establish a novel model of dynamic web service com...

Denghui Wang; Hao Huang; Changsheng Xie

2014-01-01T23:59:59.000Z

206

Modeling and Optimization of the Condensing Steam Turbine Network of a Chemical Plant  

Science Journals Connector (OSTI)

The model manager implements the thermodynamic and empirical modeling structure shown in Figure 3. Two models are newly built or rebuilt for each steam turbine on an offline basis. ... If the RMSE is beyond the predefined threshold, the model manager is used to rebuild the models, to remove the process-model mismatch. ... The optimization client serves to show the current and optimal operating values and the performance indicators on the process flow diagrams wherever the intranet is available. ...

In-Su Han; Young-Hak Lee; Chonghun Han

2005-12-13T23:59:59.000Z

207

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

208

Optimization of Switched Reluctance Motor for Efficiency Improvement Using Response Surface Model and Kriging Model  

Science Journals Connector (OSTI)

This paper presented an optimization of switched reluctance motor for higher efficiency. The motor in this study was designed based on the magnetic energy conversion loop according to the power requirements of application system. It's found that besides ... Keywords: switched reluctance motor, optimziation, RSM, Kriging Model

Xueguan Song; Youngchul Park; Jian Li; Joonho Lee

2011-04-01T23:59:59.000Z

209

Advances in Mathematical Programming ModelsAdvances in Mathematical Programming Models for Enterprise-wide Optimization  

E-Print Network [OSTI]

(EWO) EWO involves optimizing the operations of R&D, material supply, manufacturing, distribution of Crude Transfer of Crude Refinery Processing Refinery Processing Schedule Products Schedule ProductsModeling Systems OperationalOperational AnalysisAnalysis Materials RequirementMaterials Requirement Planning

Grossmann, Ignacio E.

210

Multi-model Simulation for Optimal Control of Aeroacoustics.  

SciTech Connect (OSTI)

Flow-generated noise, especially rotorcraft noise has been a serious concern for bothcommercial and military applications. A particular important noise source for rotor-craft is Blade-Vortex-Interaction (BVI)noise, a high amplitude, impulsive sound thatoften dominates other rotorcraft noise sources. Usually BVI noise is caused by theunsteady flow changes around various rotor blades due to interactions with vorticespreviously shed by the blades. A promising approach for reducing the BVI noise isto use on-blade controls, such as suction/blowing, micro-flaps/jets, and smart struc-tures. Because the design and implementation of such experiments to evaluate suchsystems are very expensive, efficient computational tools coupled with optimal con-trol systems are required to explore the relevant physics and evaluate the feasibilityof using various micro-fluidic devices before committing to hardware.In this thesis the research is to formulate and implement efficient computationaltools for the development and study of optimal control and design strategies for com-plex flow and acoustic systems with emphasis on rotorcraft applications, especiallyBVI noise control problem. The main purpose of aeroacoustic computations is todetermine the sound intensity and directivity far away from the noise source. How-ever, the computational cost of using a high-fidelity flow-physics model across thefull domain is usually prohibitive and itmight also be less accurate because of thenumerical diffusion and other problems. Taking advantage of the multi-physics andmulti-scale structure of this aeroacoustic problem, we develop a multi-model, multi-domain (near-field/far-field) method based on a discontinuous Galerkin discretiza-tion. In this approach the coupling of multi-domains and multi-models is achievedby weakly enforcing continuity of normal fluxes across a coupling surface. For ourinterested aeroacoustics control problem, the adjoint equations that determine thesensitivity of the cost functional to changes in control are also solved with same ap-proach by weakly enforcing continuity ofnormal fluxes across a coupling surface.Such formulations have been validated extensively for several aeroacoustics state andcontrol problems.A multi-model based optimal control framework has been constructed and ap-plied to our interested BVI noise control problem. This model problem consists ofthe interaction of a compressible vortex with Bell AH-1 rotor blade with wall-normal3 velocity used as control on the rotor blade surface. The computational domain isdecomposed into the near-field and far-field. The near-field is obtained by numericalsolution of the Navier-Stokes equations while far away from the noise source, wherethe effect of nonlinearities is negligible, the linearized Euler equations are used tomodel the acoustic wave propagation. The BVI wave packet is targeted by definingan objective function that measures the square amplitude of pressure fluctuations inan observation region, at a time interval encompassing the dominant leading edgecompressibility waves. Our control results show that a 12dB reduction in the ob-servation region is obtained. Interestingly, the control mechanism focuses on theobservation region and only minimize the sound level in that region at the expense ofother regions. The vortex strength and trajectory get barely changed. However, theoptimal control does alter the interaction of the vortical and potential fields, whichis the source of BVI noise. While this results in a slight increase in drag, there is asignificant reduction in the temporal gradient of lift leading to a reduction in BVIsound levels.4

Collis, Samuel Scott; Chen, Guoquan

2005-05-01T23:59:59.000Z

211

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

212

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)

213

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

SciTech Connect (OSTI)

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

214

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

215

Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) into the Blast Furnace  

SciTech Connect (OSTI)

Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process.

Dr. Chenn Zhou

2008-10-15T23:59:59.000Z

216

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

217

Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model  

E-Print Network [OSTI]

Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model):355-377. Please consult that version for citations #12;2 Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model Abstract: In this paper we define fisheries management as sustainable

Woodward, Richard T.

218

Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines  

E-Print Network [OSTI]

Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Jair was coupled to the floating wind turbine simulator FAST. The results of the comparison study indicate the need

Victoria, University of

219

OPTIMAL INVESTMENT POLICIES FOR THE HORSE RACE MODEL Thomas S. Ferguson and C. Zachary Gilstein  

E-Print Network [OSTI]

OPTIMAL INVESTMENT POLICIES FOR THE HORSE RACE MODEL Thomas S. Ferguson and C. Zachary Gilstein UCLA and Bell Communications May 1985, revised 2004 Abstract. Optimal investment policies for maximizing the expected value of the utility of an investor's fortune are presented for investment models

Ferguson, Thomas S.

220

Parameter optimization for the Gaussian model of protein foldingq Albert Erkipa  

E-Print Network [OSTI]

of protein folding and ligand docking are large and complex. Few systematic methods have yet been developed apply this parameter optimization method to the recently developed Gaussian model of protein folding Science Ltd. All rights reserved. Keywords: Gaussian model; Protein folding; Parameter optimization 1

Seok, Chaok

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


221

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

222

Reliability-yield allocation for semiconductor integrated circuits: modeling and optimization  

E-Print Network [OSTI]

This research develops yield and reliability models for fault-tolerant semiconductor integrated circuits and develops optimization algorithms that can be directly applied to these models. Since defects cause failures in microelectronics systems...

Ha, Chunghun

2005-11-01T23:59:59.000Z

223

Parameter Optimization in an Intermediate Coupled Climate Model with Biased Physics  

Science Journals Connector (OSTI)

Imperfect physical parameterization schemes in a coupled climate model are an important source of model biases that adversely impact climate prediction. However, how observational information should be used to optimize physical parameterizations ...

Xuefeng Zhang; Shaoqing Zhang; Zhengyu Liu; Xinrong Wu; Guijun Han

224

OLAF _ A General Modeling System to Evaluate and Optimize the Location of an Air  

E-Print Network [OSTI]

OLAF _ A General Modeling System to Evaluate and Optimize the Location of an Air Polluting Facility Project Report J"org Fliege 13 2.1The Meteorological Preprocessor ..................13 2.2The Air Dispersion Model

Fliege, Jörg

225

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.

226

Subcycled dynamics in the Spectral Community Atmosphere Model, version 4  

SciTech Connect (OSTI)

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

227

Optimal SCR Control Using Data-Driven Models  

SciTech Connect (OSTI)

We present an optimal control solution for the urea injection for a heavy-duty diesel (HDD) selective catalytic reduction (SCR). The approach taken here is useful beyond SCR and could be applied to any system where a control strategy is desired and input-output data is available. For example, the strategy could also be used for the diesel oxidation catalyst (DOC) system. In this paper, we identify and validate a one-step ahead Kalman state-space estimator for downstream NOx using the bench reactor data of an SCR core sample. The test data was acquired using a 2010 Cummins 6.7L ISB production engine with a 2010 Cummins production aftertreatment system. We used a surrogate HDD federal test procedure (FTP), developed at Michigan Technological University (MTU), which simulates the representative transients of the standard FTP cycle, but has less engine speed/load points. The identified state-space model is then used to develop a tunable cost function that simultaneously minimizes NOx emissions and urea usage. The cost function is quadratic and univariate, thus the minimum can be computed analytically. We show the performance of the closed-loop controller in using a reduced-order discrete SCR simulator developed at MTU. Our experiments with the surrogate HDD-FTP data show that the strategy developed in this paper can be used to identify performance bounds for urea dose controllers.

Stevens, Andrew J.; Sun, Yannan; Lian, Jianming; Devarakonda, Maruthi N.; Parker, Gordon

2013-04-16T23:59:59.000Z

228

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

229

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

230

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

231

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

232

Operational Model forOperational Model forOperational Model forOperational Model for C3 Feedstock Optimization on aC3 Feedstock Optimization on app  

E-Print Network [OSTI]

Optimization on aC3 Feedstock Optimization on app Polypropylene Production FacilityPolypropylene Production for Advanced Process Decision-making Enterprise-Wide Optimization (EWO) Meeting ­ March 13-14, 2012 #12;Project ~95% propylene Refinery PolypropylenePropylene (91%) Grade (RG) Reactor effluent Distillation ~79

Grossmann, Ignacio E.

233

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

234

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

235

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

236

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

237

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

238

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

239

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

240

Developing Generic Dynamic Models for the 2030 Eastern Interconnection Grid  

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

Oneida Tribe of Indians of Wisconsin Energy Optimization Model  

SciTech Connect (OSTI)

Oneida Nation is located in Northeast Wisconsin. The reservation is approximately 96 square miles (8 miles x 12 miles), or 65,000 acres. The greater Green Bay area is east and adjacent to the reservation. A county line roughly splits the reservation in half; the west half is in Outagamie County and the east half is in Brown County. Land use is predominantly agriculture on the west 2/3 and suburban on the east 1/3 of the reservation. Nearly 5,000 tribally enrolled members live in the reservation with a total population of about 21,000. Tribal ownership is scattered across the reservation and is about 23,000 acres. Currently, the Oneida Tribe of Indians of Wisconsin (OTIW) community members and facilities receive the vast majority of electrical and natural gas services from two of the largest investor-owned utilities in the state, WE Energies and Wisconsin Public Service. All urban and suburban buildings have access to natural gas. About 15% of the population and five Tribal facilities are in rural locations and therefore use propane as a primary heating fuel. Wood and oil are also used as primary or supplemental heat sources for a small percent of the population. Very few renewable energy systems, used to generate electricity and heat, have been installed on the Oneida Reservation. This project was an effort to develop a reasonable renewable energy portfolio that will help Oneida to provide a leadership role in developing a clean energy economy. The Energy Optimization Model (EOM) is an exploration of energy opportunities available to the Tribe and it is intended to provide a decision framework to allow the Tribe to make the wisest choices in energy investment with an organizational desire to establish a renewable portfolio standard (RPS).

Troge, Michael [Project Manager

2014-12-30T23:59:59.000Z

242

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

SciTech Connect (OSTI)

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

243

Modeling System Development for the Evaluation of Dynamic Air Quality  

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

244

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint  

SciTech Connect (OSTI)

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

245

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

246

Multi-objective stochastic dynamic economic emission dispatch enhancement by fuzzy adaptive modified theta particle swarm optimization  

Science Journals Connector (OSTI)

This paper presents a new method based on fuzzy adaptive modified theta particle swarm optimization to investigate the multiobjective day-ahead dynamic economic emission dispatch (DEED) problem considering the effect of wind power generators. The proposed algorithm concurrently reduces the total fuel cost as well as the total emission during the optimization process. Besides by considering the uncertainty of hourly load/wind forecast a scenario-based approach has been implemented such that the DEED problem would be studied in a stochastic environment referred to as stochastic DEED. In order to see the efficiency and feasibility of the proposed method two standard test systems are employed as the case studies.

Bahman Bahmanifirouzi; Ebrahim Farjah; Taher Niknam

2012-01-01T23:59:59.000Z

247

Modeling Zero Energy Building: technical and economical optimization Maria Ferrara1-2  

E-Print Network [OSTI]

1 Modeling Zero Energy Building: technical and economical optimization Maria Ferrara1-2 , Joseph by the recast of Energy Performance of Buildings. The aim of this work is to provide a useful method to deal combines the use of TRNSYS, building energy simulation program, with GenOpt, Generic Optimization program

Paris-Sud XI, Université de

248

RANS-based Aerodynamic Shape Optimization Investigations of the Common Research Model Wing  

E-Print Network [OSTI]

RANS-based Aerodynamic Shape Optimization Investigations of the Common Research Model Wing Zhoujie of Michigan, Ann Arbor, MI The aerodynamic shape optimization of transonic wings requires Reynolds, and viscous effects. While there has been some research dedicated to RANS-based aerodynamic shape optimiza

Papalambros, Panos

249

Chemical-equilibrium model of optimal a-Si:H growth from SiH4  

Science Journals Connector (OSTI)

A model of optimal hydrogenated-amorphous-silicon growth based on bulk chemical reactions involving Si-Si and Si-H bonds is proposed. The optimal growth temperature is determined by the balance between the rate of hydrogen diffusion and the rate of film growth.

K. Winer

1990-04-15T23:59:59.000Z

250

A Network Modeling Approach Optimization of Internet-Based Advertising Strategies and Pricing  

E-Print Network [OSTI]

A Network Modeling Approach for the Optimization of Internet-Based Advertising Strategies and evaluation of optimal Internet mar- keting strategies when a firm is advertising on multiple websites examples are constructed that demonstrate two paradoxes: (1). that advertising on more websites may reduce

Nagurney, Anna

251

Power system analysis project Modeling and Sizing optimization of Stand-alone  

E-Print Network [OSTI]

Power system analysis project Modeling and Sizing optimization of Stand-alone photovoltaic/wind-in, cut-out wind speed and rated power, into the optimization based on the real load of the site and write wind turbine is used to adopt its advantage of low noise and relatively low requirement of the quality

Lavaei, Javad

252

Implementation aspects of interactive multiobjective optimization for modeling environments: the case of GAMS-NIMBUS  

Science Journals Connector (OSTI)

Interactive multiobjective optimization methods have provided promising results in the literature but still their implementations are rare. Here we introduce a core structure of interactive methods to enable their convenient implementation. We also demonstrate ... Keywords: Interactive methods, Modeling languages, Multiple objective programming, NIMBUS method, Pareto optimality

Vesa Ojalehto, Kaisa Miettinen, Timo Laukkanen

2014-07-01T23:59:59.000Z

253

Capacity Constraints Across Nests in Assortment Optimization Under the Nested Logit Model  

E-Print Network [OSTI]

Capacity Constraints Across Nests in Assortment Optimization Under the Nested Logit Model Jacob B Abstract We consider assortment optimization problems when customers choose according to the nested logit in all nests. When each product consumes one unit of capacity, our capacity constraint limits

Topaloglu, Huseyin

254

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

255

A novel optimization sizing model for hybrid solar-wind power generation system  

Science Journals Connector (OSTI)

This paper develops the Hybrid Solar-Wind System Optimization Sizing (HSWSO) model, to optimize the capacity sizes of different components of hybrid solar-wind power generation systems employing a battery bank. The HSWSO model consists of three parts: the model of the hybrid system, the model of Loss of Power Supply Probability (LPSP) and the model of the Levelised Cost of Energy (LCE). The flow chart of the HSWSO model is also illustrated. With the incorporated HSWSO model, the sizing optimization of hybrid solar-wind power generation systems can be achieved technically and economically according to the system reliability requirements. A case study is reported to show the importance of the HSWSO model for sizing the capacities of wind turbines, PV panel and battery banks of a hybrid solar-wind renewable energy system.

Hongxing Yang; Lin Lu; Wei Zhou

2007-01-01T23:59:59.000Z

256

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

257

Optimization of hybrid dynamic/steady-state processes using process integration  

E-Print Network [OSTI]

-batch water purification system was optimized. This problem showed how process integration could be used to optimize a hybrid system and gain insights into the process under many different operating conditions....

Grooms, Daniel Douglas

2009-06-02T23:59:59.000Z

258

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

259

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

260

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

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.

262

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

263

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

264

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

265

Optimal power grid protection through a defender–attacker–defender model  

Science Journals Connector (OSTI)

Abstract Power grid vulnerability is a major concern of our society, and its protection problem is often formulated as a tri-level defender–attacker–defender model. However, this tri-level problem is computationally challenging. In this paper, we design and implement a Column-and-Constraint Generation algorithm to derive its optimal solutions. Numerical results on an IEEE system show that: (i) the developed algorithm identifies optimal solutions in a reasonable time, which significantly outperforms the existing exact algorithm; (ii) the attack solution obtained through solving the attacker–defender model does not lead to the optimal protection plan in general; and (iii) protection using the optimal solution from the defender–attacker–defender model always improves the grid survivability under contingencies. The proposed model and algorithm can be easily modified to accommodate for other critical infrastructure network protection problems.

Wei Yuan; Long Zhao; Bo Zeng

2014-01-01T23:59:59.000Z

266

Geometric modeling and optimization in 3D solar cells : implementation and algorithms  

E-Print Network [OSTI]

Conversion of solar energy in three-dimensional (3D) devices has been essentially untapped. In this thesis, I design and implement a C++ program that models and optimizes a 3D solar cell ensemble embedded in a given ...

Wan, Jin Hao, M. Eng. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

267

Applying methods of numerical modeling to optimize a plasma burner of atmospheric pressure  

Science Journals Connector (OSTI)

The shape of a plasma burner is optimized by the methods of numerical modeling. Vortex-free flow is created in the burner merely at the expense of selecting the external tube profile rather than by introductio...

S. M. Perminov; V. N. Perminova…

1993-09-01T23:59:59.000Z

268

New methodologies for top-down statistical modeling and optimization of integrated circuits  

E-Print Network [OSTI]

New methodologies intended to facilitate system level design and optimization are developed. Specifically, these methodologies allow: (1) development of system level models for the purpose of gathering statistical data on the performance of large...

Alexander, Daniel D.

2012-06-07T23:59:59.000Z

269

Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed  

SciTech Connect (OSTI)

Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.

Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li [Southeast University, Nanjing (China). Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education

2008-05-15T23:59:59.000Z

270

Architecture-driven reliability optimization with uncertain model parameters  

Science Journals Connector (OSTI)

It is currently considered good software engineering practice to decide between design alternatives based on quantitative architecture evaluations for different quality attributes, such as reliability and performance. However, the results of these quantitative ... Keywords: Architecture optimization, Monte-Carlo simulation, Parameter uncertainty, Probabilistic quality prediction, Reliability

Indika Meedeniya; Aldeida Aleti; Lars Grunske

2012-10-01T23:59:59.000Z

271

DYNAMICAL MODEL OF AN EXPANDING SHELL  

SciTech Connect (OSTI)

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

272

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

273

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

274

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

275

Latitude Based Model for Tilt Angle Optimization for Solar Collectors in the Mediterranean Region  

Science Journals Connector (OSTI)

Abstract This paper inspects the different parameters that intervene in the determination of the optimal tilt angle for maximum solar energy collection. It proposes a method for calculating the optimal tilt angle based upon the values of the daily global solar radiation on a horizontal surface. A computer program using the mathematical model to calculate the solar radiation incident on an inclined surface as a function of the tilt angle is implemented. Four years data of daily global solar radiation on a horizontal surface in 35 sites in different countries of the Mediterranean region is used. The program assumes a due south orientation of the collectors and it determines the optimal tilt angle for maximum solar radiation collection for sites in the Mediterranean region. A regression analysis using the results of the computer simulation is conducted to develop a latitude based tilt angle optimization mathematical model for maximum solar radiation collection for the sites. We tested both a linear and a quadratic model (of the form ax2+bx) for representing the relationship between the annual optimal tilt angle and the site's latitude. The quadratic model is better; it provides very high prediction accuracy. 99.87% of the variation in the annual optimal tilt angle is explained by the variability in site's latitude with an average residual angle of only 0.96° for all 35 sites studied. It also gives an average percentage decrease in the annual solar radiation of only 0.016% when compared with actual optimal tilt angles.

Hassane Darhmaoui; Driss Lahjouji

2013-01-01T23:59:59.000Z

276

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

277

Optimizing Large Scale Chemical Transport Models for Multicore Platforms John C. Linford and Adrian Sandu  

E-Print Network [OSTI]

Optimizing Large Scale Chemical Transport Models for Multicore Platforms John C. Linford and Adrian: Chemical Transport Model, Domain Decom- position, Time Splitting, Multicore, Scalability, IBM Cell Broadband Engine, Intel Quad-Core Xeon. Abstract The performance of a typical chemical transport model

Sandu, Adrian

278

International Conference of Modeling, Optimization and Simulation -MOSIM'12 June 06-08, 2012 Bordeaux -France  

E-Print Network [OSTI]

9th International Conference of Modeling, Optimization and Simulation - MOSIM'12 June 06-08, 2012 Physical Systems (CPS), has arisen. In terms of modeling and simulation, CPS--like many technical systems-oriented Modeling and Simulation, Causality, Cyber-Physical System (CPS), algorithmic loop, instantaneous multiple

Boyer, Edmond

279

Optimal Location of Compressed Natural Gas (CNG) Refueling Station Using the Arc Demand Coverage Model  

Science Journals Connector (OSTI)

In this paper a model that locates Compressed Natural Gas (CNG) refueling stations to cover the full volume of vehicle flows is developed and applied. The model inputs consist of a road network include nodes and arcs, the volume of vehicle flows between ... Keywords: Compressed Natural Gas, Arc Demand Coverage Model, Optimal Location, Network

Abtin Boostani; Reza Ghodsi; Ali Kamali Miab

2010-05-01T23:59:59.000Z

280

Optimizing a physical security configuration using a highly detailed simulation model  

E-Print Network [OSTI]

Optimizing a physical security configuration using a highly detailed simulation model Marechal, T. Email: tommarechal@hotmail.com Abstract This chapter focuses on using a highly detailed simulation model. In this chapter describes the use of a highly detailed simulation model to find a superior security configuration

Smith, Alice E.

Note: This page contains sample records for the topic "dynamic optimization model" 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

Shared memory optimizations for distributed memory programming models  

Science Journals Connector (OSTI)

In the world of parallel programming, there are two major classes of programming models: shared memory and distributed memory. Shared memory models share all memory by default, and are most effective on multi-processor systems. Distributed memory models ...

Andrew Friedley / Andrew Lumsdaine

2013-01-01T23:59:59.000Z

282

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

283

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.

284

Optimization of the GB/SA Solvation Model for Predicting the Structure of Surface Loops in Proteins  

E-Print Network [OSTI]

Optimization of the GB/SA Solvation Model for Predicting the Structure of Surface Loops in ProteinsVed: October 10, 2005; In Final Form: December 1, 2005 Implicit solvation models are commonly optimized the force field is sometimes not considered. In previous studies, we have developed an optimization

Meirovitch, Hagai

285

Optimization of global model composed of radial basis functions using the term-ranking approach  

SciTech Connect (OSTI)

A term-ranking method is put forward to optimize the global model composed of radial basis functions to improve the predictability of the model. The effectiveness of the proposed method is examined by numerical simulation and experimental data. Numerical simulations indicate that this method can significantly lengthen the prediction time and decrease the Bayesian information criterion of the model. The application to real voice signal shows that the optimized global model can capture more predictable component in chaos-like voice data and simultaneously reduce the predictable component (periodic pitch) in the residual signal.

Cai, Peng; Tao, Chao, E-mail: taochao@nju.edu.cn; Liu, Xiao-Jun [Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China)] [Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China)

2014-03-15T23:59:59.000Z

286

Asperity Model of an Earthquake - Dynamic Problem  

SciTech Connect (OSTI)

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

287

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

288

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

289

Clustering properties of dynamical dark energy models  

SciTech Connect (OSTI)

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

290

Mixed integer model for optimizing equipment scheduling and overburden transport in a surface coal mining operation  

SciTech Connect (OSTI)

The lack of available techniques prompted the development of a mixed integer model to optimize the scheduling of equipment and the distribution of overburden in a typical mountaintop removal operation. Using this format, a (0-1) integer model and transportation model were constructed to determine the optimal equipment schedule and optimal overburden distribution, respectively. To solve this mixed integer program, the model was partitioned into its binary and real-valued components. Each problem was successively solved and their values added to form estimates of the value of the mixed integer program. Optimal convergence was indicated when the difference between two successive estimates satisfied some pre-specific accuracy value. The performance of the mixed integer model was tested against actual field data to determine its practical applications. To provide the necessary input information, production data was obtained from a single seam, mountaintop removal operation located in the Appalachian coal field. As a means of analyzing the resultant equipment schedule, the total idle time was calculated for each machine type and each lift location. Also, the final overburden assignments were analyzed by determining the distribution of spoil material for various overburden removal productivities. Subsequent validation of the mixed integer model was conducted in two distinct areas. The first dealt with changes in algorithmic data and their effects on the optimality of the model. The second area concerned variations in problem structure, specifically those dealing with changes in problem size and other user-inputed values such as equipment productivities or required reclamation.

Goodman, G.V.R.

1987-01-01T23:59:59.000Z

291

Empirical Performance Model-Driven Data Layout Optimization and Library Call Selection for Tensor Contraction Expressions  

SciTech Connect (OSTI)

Empirical optimizers like ATLAS have been very effective in optimizing computational kernels in libraries. The best choice of parameters such as tile size and degree of loop unrolling is determined by executing different versions of the computation. In contrast, optimizing compilers use a model-driven approach to program transformation. While the model-driven approach of optimizing compilers is generally orders of magnitude faster than ATLAS-like library generators, its effectiveness can be limited by the accuracy of the performance models used. In this paper, we describe an approach where a class of computations is modeled in terms of constituent operations that are empirically measured, thereby allowing modeling of the overall execution time. The performance model with empirically determined cost components is used to perform data layout optimization together with the selection of library calls and layout transformations in the context of the Tensor Contraction Engine, a compiler for a high-level domain-specific language for expressing computational models in quantum chemistry. The effectiveness of the approach is demonstrated through experimental measurements on representative computations from quantum chemistry.

Lu, Qingda; Gao, Xiaoyang; Krishnamoorthy, Sriram; Baumgartner, Gerald; Ramanujam, J.; Sadayappan, Ponnuswamy

2012-03-01T23:59:59.000Z

292

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

293

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

294

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

295

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.

296

Optimization Model for Energy Planning with CO2 Emission Considerations  

Science Journals Connector (OSTI)

This paper considers the problem of reducing CO2 emissions from a power grid consisting of a variety of power-generating plants:? coal, natural gas, nuclear, hydroelectric, and alternative energy. ... Approximately 28.5% of OPG electricity is produced through the combustion of fossil fuels, 27% through hydroelectricity, and 44% through nuclear energy, and the remaining 0.5% comes from renewable or other energy sources, such as wind turbines. ... A sensitivity analysis was also performed to evaluate the impact of natural gas prices, coal prices, and retrofit costs on the optimal configuration of the OPG fleet of electricity-generating stations. ...

Haslenda Hashim; Peter Douglas; Ali Elkamel; Eric Croiset

2005-01-12T23:59:59.000Z

297

Capacity analysis, cycle time optimization, and supply chain strategy in multi-product biopharmaceutical manufacturing operations  

E-Print Network [OSTI]

Application of system optimization theory, supply chain principles, and capacity modeling are increasingly valuable tools for use in pharmaceutical manufacturing facilities. The dynamics of the pharmaceutical industry - ...

Fetcho-Phillips, Kacey L. (Kacey Lynn)

2011-01-01T23:59:59.000Z

298

Optimization Online - A Non-Parametric Structural Hybrid Modeling ...  

E-Print Network [OSTI]

Jun 30, 2014 ... Keywords: Electricity market; Electricity price modeling; Energy trading; Supply stack. Category 1: Applications -- OR and Management ...

Somayeh Moazeni

2014-06-30T23:59:59.000Z

299

A system-level cost-of-energy wind farm layout optimization with landowner modeling  

SciTech Connect (OSTI)

This work applies an enhanced levelized wind farm cost model, including landowner remittance fees, to determine optimal turbine placements under three landowner participation scenarios and two land-plot shapes. Instead of assuming a continuous piece of land is available for the wind farm construction, as in most layout optimizations, the problem formulation represents landowner participation scenarios as a binary string variable, along with the number of turbines. The cost parameters and model are a combination of models from the National Renewable Energy Laboratory (NREL), Lawrence Berkeley National Laboratory, and Windustiy. The system-level cost-of-energy (COE) optimization model is also tested under two land-plot shapes: equally-sized square land plots and unequal rectangle land plots. The optimal COEs results are compared to actual COE data and found to be realistic. The results show that landowner remittances account for approximately 10% of farm operating costs across all cases. Irregular land-plot shapes are easily handled by the model. We find that larger land plots do not necessarily receive higher remittance fees. The model can help site developers identify the most crucial land plots for project success and the optimal positions of turbines, with realistic estimates of costs and profitability. (C) 2013 Elsevier Ltd. All rights reserved.

Chen, Le [Ames Laboratory; MacDonald, Erin [Ames Laboratory

2013-10-01T23:59:59.000Z

300

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

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


301

NOVEL APROACH TO PROCESS SYNTHESIS BASED ON DYNAMIC OPTIMIZATION AND EXPLOITION OF PROCESS  

E-Print Network [OSTI]

is industrially relevant gas phase catalytic reaction ­ methane steam reforming accompanied with water gas shift the interaction of design and control and therefore it is usually suboptimal from both economic and control operation, design and control. Optimization objectives are economical and optimization results provide

Van den Hof, Paul

302

An Optimization Model for Plug-In Hybrid Electric Vehicles  

SciTech Connect (OSTI)

The necessity for environmentally conscious vehicle designs in conjunction with increasing concerns regarding U.S. dependency on foreign oil and climate change have induced significant investment towards enhancing the propulsion portfolio with new technologies. More recently, plug-in hybrid electric vehicles (PHEVs) have held great intuitive appeal and have attracted considerable attention. PHEVs have the potential to reduce petroleum consumption and greenhouse gas (GHG) emissions in the commercial transportation sector. They are especially appealing in situations where daily commuting is within a small amount of miles with excessive stop-and-go driving. The research effort outlined in this paper aims to investigate the implications of motor/generator and battery size on fuel economy and GHG emissions in a medium-duty PHEV. An optimization framework is developed and applied to two different parallel powertrain configurations, e.g., pre-transmission and post-transmission, to derive the optimal design with respect to motor/generator and battery size. A comparison between the conventional and PHEV configurations with equivalent size and performance under the same driving conditions is conducted, thus allowing an assessment of the fuel economy and GHG emissions potential improvement. The post-transmission parallel configuration yields higher fuel economy and less GHG emissions compared to pre-transmission configuration partly attributable to the enhanced regenerative braking efficiency.

Malikopoulos, Andreas [ORNL] [ORNL; Smith, David E [ORNL] [ORNL

2011-01-01T23:59:59.000Z

303

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

304

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

305

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

306

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

307

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

308

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

309

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

310

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

311

Green Petroleum Refining -Mathematical Models for Optimizing Petroleum Refining Under Emission Constraints  

E-Print Network [OSTI]

Green Petroleum Refining - Mathematical Models for Optimizing Petroleum Refining Under Emission understand that my thesis may be made electronically available to the public. #12;iii Abstract Petroleum and treating options for petroleum refinery waste streams. The performance of the developed model

Anderson, Charles H.

312

The Need for a Full-Chip and Package Thermal Model for Thermally Optimized IC Designs  

E-Print Network [OSTI]

ceramic ball-grid array (CBGA) pack- age consisting of the chip (die), thermal interface material, heatThe Need for a Full-Chip and Package Thermal Model for Thermally Optimized IC Designs Wei Huang detailed die temperature with a full-chip thermal model at early design stages is important to discover

Skadron, Kevin

313

Identification of Bouc-Wen type models using multi-objective optimization algorithms  

Science Journals Connector (OSTI)

Most of the published literature concerned with the parameter estimation of the Bouc-Wen model of hysteresis via evolutionary algorithms uses a single objective function (the mean square error between the known displacements and the estimated ones) and ... Keywords: Bouc-Wen-Baber-Noori model, Hysteresis, Multi-objective optimization, NSGA-II, System identification

Gilberto A. Ortiz; Diego A. Alvarez; Daniel Bedoya-RuíZ

2013-01-01T23:59:59.000Z

314

Modeling and Computational Strategies for Optimal Development Planning of Offshore Oilfields under Complex Fiscal Rules  

Science Journals Connector (OSTI)

Modeling and Computational Strategies for Optimal Development Planning of Offshore Oilfields under Complex Fiscal Rules ... In particular, we consider a recently proposed multifield site strategic planning model for offshore oil and gas fields as a basis to include the generic fiscal rules with ringfencing provisions. ...

Vijay Gupta; Ignacio E. Grossmann

2012-09-29T23:59:59.000Z

315

Longitudinal Data Analysis Using Multilevel Linear Modeling (MLM): Fitting an Optimal Variance-Covariance Structure  

E-Print Network [OSTI]

LONGITUDINAL DATA ANALYSIS USING MULTILEVEL LINEAR MODELING (MLM): FITTING AN OPTIMAL VARIANCE-COVARIANCE STRUCTURE A Dissertation by YUAN-HSUAN LEE Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY August 2010 Major Subject: Educational Psychology Longitudinal Data Analysis Using Multilevel Linear Modeling (MLM...

Lee, Yuan-Hsuan

2011-10-21T23:59:59.000Z

316

Modeling of switched reluctance motors based on optimized BP neural networks with parallel chaotic search  

Science Journals Connector (OSTI)

Precise modeling of switched reluctant motor (SRM) is important of switched reluctant motor driving system. In the article, modeling of SRM by a BP neural network with parallel chaotic search (PCS) is presented firstly. Here parallel chaotic search is ... Keywords: BP neural network, optimize, parallel chaotic search, switched reluctant motor

Yong Cheng; Hui Lin

2010-03-01T23:59:59.000Z

317

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model  

E-Print Network [OSTI]

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model Zhendong Luoa) for the tropical Pacific Ocean reduced gravity model. Ensembles of data are compiled from transient solutions computed from the discrete equation system derived by FDS for the tropical Pacific Ocean reduced gravity

Aluffi, Paolo

318

Models for Optimization of Energy Consumption of Pumps in a Wastewater Processing Plant  

E-Print Network [OSTI]

Models for Optimization of Energy Consumption of Pumps in a Wastewater Processing Plant Zijun Zhang in the wastewater preliminary treatment process is discussed. Data- mining algorithms are utilized to develop pump performance models based on industrial data collected at a municipal wastewater processing plant

Kusiak, Andrew

319

Modeling, Optimization, and Experimentation with a Two Stage Mixed Gas Cascaded Joule Thomson Cryoprobe  

E-Print Network [OSTI]

Modeling, Optimization, and Experimentation with a Two Stage Mixed Gas Cascaded Joule Thomson-stage Mixed Gas Joule Thomson (MGJT) cycle is capable of providing compact cooling for cryoprobes". A computational model of a commercially available two stage MGJT cryoprobe donated by American Medical Systems

Wisconsin at Madison, University of

320

Short-term production optimization of offshore oil and gas production using nonlinear model predictive control  

Science Journals Connector (OSTI)

The topic of this paper is the application of nonlinear model predictive control (NMPC) for optimizing control of an offshore oil and gas production facility. Of particular interest is the use of NMPC for direct short-term production optimization, where two methods for (one-layer) production optimization in NMPC are investigated. The first method is the unreachable setpoints method where an unreachable setpoint is used in order to maximize oil production. The ideas from this method are combined with the exact penalty function for soft constraints in a second method, named infeasible soft-constraints. Both methods can be implemented within standard NMPC software tools. The case-study first looks into the use of NMPC for ‘conventional’ pressure control, where disturbance rejection of time-varying disturbances (caused, e.g., by the ‘slugging’ phenomenon) is an issue. Then the above two methods for production optimization are employed, where both methods find the economically optimal operating point. Two different types of reservoir models are studied, using rate-independent and rate-dependent gas/oil ratios. These models lead to different types of optimums. The relative merits of the two methods for production optimization, and advantages of the two one-layer approaches compared to a two-layer structure, are discussed.

Anders Willersrud; Lars Imsland; Svein Olav Hauger; Pål Kittilsen

2013-01-01T23:59:59.000Z

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


321

Optimization Online - Robustified Reserve Modelling for Wind Power ...  

E-Print Network [OSTI]

Jul 8, 2014 ... Robustified Reserve Modelling for Wind Power Integration in Ramp-Based Unit Commitment. German Morales-España(gmorales ***at*** ...

German Morales-España

2014-07-08T23:59:59.000Z

322

A nonlinear binary programming model for electric distribution systems reliability optimization  

Science Journals Connector (OSTI)

This paper presents a new nonlinear binary programming model aiming to minimize the SAIDI and SAIFI reliability indices of a distribution feeder. Graph theory and a contingency simulation-based technique are used in the explicit formulation of the objective functions to accurately model the protection system response to faults and system reconfiguration practices. To ensure the solution’s feasibility both technical and economic constraints are considered. An alternative economic constraint is proposed, taking into account the current locations of the protective devices and sectionalizing switches, which directly affect the utility costs for reliability improvement. To solve the proposed model, an optimization technique based on the branch-and-bound algorithm is used in this paper. Hence, this technique enables deterministic optimization of distribution feeder reliability by identifying types and locations of protection devices and sectionalizing switches, so that SAIDI and SAIFI reliability indices are minimized. Test cases are presented to illustrate the reliability optimization of a test feeder considering the use of different protection schemes and cost constraints. A value-based reliability optimization formulation is derived from the proposed model and its application to the test feeder is also illustrated. Additionally, the solutions obtained from the proposed model are compared with the solutions obtained from two other state-of-the-art models found in the literature. A comparative study is also carried out to evaluate the efficiency of the genetic algorithm in solving the proposed models.

G.D. Ferreira; A.S. Bretas

2012-01-01T23:59:59.000Z

323

Optimal Futures Market Strategies for Energy Service Providers  

Science Journals Connector (OSTI)

The previous chapter focused on developing a stochastic model for the dynamics of electricity prices. Here we show how the bid-based model can be applied to help market participants optimize their decision making...

Petter L. Skantze; Marija D. Ilic

2001-01-01T23:59:59.000Z

324

Stable nonlinear identification from noisy repeated experiments via convex optimization  

E-Print Network [OSTI]

This paper introduces new techniques for using convex optimization to fit input-output data to a class of stable nonlinear dynamical models. We present an algorithm that guarantees consistent estimates of models in this ...

Tobenkin, Mark M.

325

Variational assimilation for xenon dynamical forecasts in neutronic using advanced background error covariance matrix modelling  

Science Journals Connector (OSTI)

Abstract Data assimilation method consists in combining all available pieces of information about a system to obtain optimal estimates of initial states. The different sources of information are weighted according to their accuracy by the means of error covariance matrices. Our purpose here is to evaluate the efficiency of variational data assimilation for the xenon induced oscillations forecasts in nuclear cores. In this paper we focus on the comparison between 3DVAR schemes with optimised background error covariance matrix B and a 4DVAR scheme. Tests were made in twin experiments using a simulation code which implements a mono-dimensional coupled model of xenon dynamics, thermal, and thermal–hydraulic processes. We enlighten the very good efficiency of the 4DVAR scheme as well as good results with the 3DVAR one using a careful multivariate modelling of B.

Angélique Ponçot; Jean-Philippe Argaud; Bertrand Bouriquet; Patrick Erhard; Serge Gratton; Olivier Thual

2013-01-01T23:59:59.000Z

326

Evolutionary dynamic optimization: A survey of the state of the art  

E-Print Network [OSTI]

needs to take into account changes during the optimization process as time goes ...... some bias so that individuals' exploration is directed toward the predicted region ..... production according to their distance from the core in Ptrack rather than ...

2012-04-09T23:59:59.000Z

327

Surgical design for the Fontan procedure using computational fluid dynamics and derivative-free optimization  

E-Print Network [OSTI]

optimal design for improved hepatic ?ow distribution 5.1hepatic ?ow distribution than other designs overall), andY-graft Design for Improved Hepatic Flow Distribution in the

Yang, Weiguang

2012-01-01T23:59:59.000Z

328

Optimal Energy Management of Automotive Battery Systems Including Thermal Dynamics and Aging  

Science Journals Connector (OSTI)

Hybrid-electric vehicles (HEV) has been the subject of intensive research as a field of application of optimal control in the past decade. In particular, researchers have proven that energy management (or supe...

Antonio Sciarretta; Domenico di Domenico…

2014-01-01T23:59:59.000Z

329

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.

330

Assimilation of satellite reflecance dataa into a dynamical leaf model to infer seasonally varying leaf area for climate and carbon models  

SciTech Connect (OSTI)

Leaf area index is an important input for many climate and carbon models. The widely used leaf area products derived from satellite-observed surface reflectances contain substantial erratic fluctuations in time due to inadequate atmospheric corrections and observational and retrieval uncertainties. These fluctuations are inconsistent with the seasonal dynamics of leaf area, known to be gradual. Their use in process-based terrestrial carbon models corrupts model behavior, making diagnosis of model performance difficult. We propose a data assimilation approach that combines the satellite observations of Moderate Resolution Imaging Spectroradiometer (MODIS) albedo with a dynamical leaf model. Its novelty is that the seasonal cycle of the directly retrieved leaf areas is smooth and consistent with both observations and current understandings of processes controlling leaf area dynamics. The approach optimizes the dynamical model parameters such that the difference between the estimated surface reflectances based on the modeled leaf area and those of satellite observations is minimized. We demonstrate the usefulness and advantage of our new approach at multiple deciduous forest sites in the United States.

Liu, Qing [Georgia Institute of Technology; Gu, Lianhong [ORNL; Dickinson, Robert E. [Georgia Institute of Technology; Tian, Y [Georgia Institute of Technology; Zhou, L [Georgia Institute of Technology; Post, Wilfred M [ORNL

2007-01-01T23:59:59.000Z

331

HEURISTIC APPROACH FOR OPTIMAL PARAMETER ESTIMATION OF ELECTRIC LOAD FORECAST MODEL  

Science Journals Connector (OSTI)

Load forecasting is a crucial aspect of electric power system planning and operation. This paper presents a heuristic approach for optimal parameter estimation of long term load forecast models. The problem is viewed as an optimization one in which the goal is to minimize the total estimation error by properly adjusting the model coefficients. A particle swarm optimization algorithm is developed to minimize the error associated with the estimated model parameters. Real data of Egyptian network is used to perform this study. Results are reported and compared to those obtained using the well known least error squares estimation technique. Comparison results are in favor of the proposed approach which signifies its potential as a promising estimation tool.

M. R. AlRashidi; K. M. EL?Naggar

2009-01-01T23:59:59.000Z

332

Optimizing the Ptolemaic Model of Planetary and Solar Motion  

E-Print Network [OSTI]

Ptolemy-s planetary model is an ancient geocentric astronomical model, describing the observed motion of the Sun and the planets. Ptolemy accounted for the deviations of planetary orbits from perfect circles by introducing two small and equal shifts into his model. We show that Ptolemy-s choice of shifts allowed him to approximate the true eccentricity of planetary orbits only in the first order, linear in eccentricity. We show that, if the shifts were tuned in the ratio 5/3, the model precision could be improved substantially, perhaps delaying its rejection. The best achievable precision is quadratic in eccentricities. Although, to achieve it fully, one would have to introduce Ptolemaic shifts in the epicycles as well as in deferents the planets.

Rushkin, Ilia

2015-01-01T23:59:59.000Z

333

Interconnect modeling and optimization in deep sub-micron technologies  

E-Print Network [OSTI]

Interconnect will be a major bottleneck for deep sub-micron technologies in the years to come. This dissertation addresses the communication aspect from a power consumption and transmission speed perspective. A model for ...

Sotiriadis, Paul Peter P. (Paul Peter Peter-Paul), 1973-

2002-01-01T23:59:59.000Z

334

An optimisation model for optimal and sustainable distribution  

Science Journals Connector (OSTI)

In many companies, a large share of costs in value chains is due to the distribution logistics. The problem is known as the vehicle routing problem (VRP) and many different algorithms are used for approximate solutions. The main point of the problem is to carry out deliveries from the central storage facility to all customers incurring minimal costs. This paper aims to present development and implementation of such a model and its application for a special distribution and customer network. Although the conceptual idea of the model is primarily based on the economical cost optimisation and consequentially on as much profit as possible, the model can simply be upgraded with ecological or environmentally friendly aspects. So the aim of the model is an optimisation tool upgraded by sustainable development of logistics and distribution.

Rok Strašek

2013-01-01T23:59:59.000Z

335

Hybrid Model for Building Performance Diagnosis and Optimal Control  

E-Print Network [OSTI]

and two capacitances, is used to simulate building envelope whose parameters are determined in frequency domain using the theoretical frequency characteristics of the envelope. Internal mass is represented by a 2R2C thermal network model, which consists...

Wang, S.; Xu, X.

2003-01-01T23:59:59.000Z

336

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

337

Accounting for the effects of rehabilitation actions on the reliability of flexible pavements: performance modeling and optimization  

E-Print Network [OSTI]

A performance model and a reliability-based optimization model for flexible pavements that accounts for the effects of rehabilitation actions are developed. The developed performance model can be effectively implemented in all the applications...

Deshpande, Vighnesh Prakash

2009-05-15T23:59:59.000Z

338

Multidisciplinary Modeling, Control, and Optimization of a Solid Oxide Fuel Cell/Gas Turbine Hybrid Power System.  

E-Print Network [OSTI]

??This thesis describes a systematical study, including multidisciplinary modeling, simulation, control, and optimization, of a fuel cell - gas turbine hybrid power system that aims… (more)

Abbassi Baharanchi, Atid

2009-01-01T23:59:59.000Z

339

Neuro-genetic approach to optimize parameter design of dynamic multiresponse experiments  

Science Journals Connector (OSTI)

Engineers have widely applied the Taguchi method, a traditional approach for robust experimental design, to a variety of quality engineering problems for enhancing system robustness. However, the Taguchi method is unable to deal with dynamic multiresponse ... Keywords: Dynamic multiresponse, Experimental design, Exponential desirability functions, Genetic algorithms, Neural networks, Taguchi method

Hsu-Hwa Chang; Yan-Kwang Chen

2011-01-01T23:59:59.000Z

340

Design of an Electron Gun using Computer Optimization  

E-Print Network [OSTI]

Design of an Electron Gun using Computer Optimization B. M. Lewis H. T. Tran Department geometry of the system. This optimization framework, to be considered in the context of electron guns the methods of shape optimization to design the cathode of an electron gun. The dynamical equations modeling

Note: This page contains sample records for the topic "dynamic optimization model" 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 continuous model for open pit mine planning? - Optimization Online  

E-Print Network [OSTI]

Sep 15, 2009 ... The model introduced here is posed in a suitable functional space, ... are described by a possibly discontinuous effort density, a scalar function defined on the three- ... Our goal here is to develop a complete existence theory and investigate some qualitative proper- ...... gence, Book Series, Springer Verlag.

2009-09-15T23:59:59.000Z

342

Modeling and optimization of a chiller plant Xiupeng Wei*  

E-Print Network [OSTI]

based on a simulation program [9]. Optimum set point of condensing water temperature for chillers to model a chiller plant that has four chillers, four cooling towers, and two chilled water storage tanks of chillers, cooling towers, pumps and chilled water storage tanks. It is frequently used to air conditioning

Kusiak, Andrew

343

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

344

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

345

Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics  

Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (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

346

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

347

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

348

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

349

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

350

Modelling of networks of production and logistics and analysis of their nonlinear dynamics  

Science Journals Connector (OSTI)

Present networks of production and logistics are characterised by increasing dynamical and structural complexity. Along with the nonlinear dynamics of such networks, an efficient planning and control can typically not be guaranteed and economic risks ... Keywords: operation and production management, optimization, supply chain management

Bernd Scholz-Reiter; Uwe Hinrichs; Reik Donner; Annette Witt

2006-05-01T23:59:59.000Z

351

Integrated method to create optimal dynamic strategic plans for corporate technology start-ups  

E-Print Network [OSTI]

This thesis presents an innovative method for evaluating and dynamically planning the development of uncertain technology investments. Its crux centers on a paradigm shift in the way managers assess investments, toward an ...

Mikati, Samir Omar

2009-01-01T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

353

Stochastic Modeling and Optimization for Robust Power Management in a Partially Observable System  

E-Print Network [OSTI]

or hard disk. The power management hardware/software monitors the state transition in the systemStochastic Modeling and Optimization for Robust Power Management in a Partially Observable System As the hardware and software complexity grows, it is unlikely for the power management hardware/software to have

Qiu, Qinru

354

Performance Optimization by Wire and Buffer Sizing Under the Transmission Line Model \\Lambda  

E-Print Network [OSTI]

Performance Optimization by Wire and Buffer Sizing Under the Transmission Line Model \\Lambda Tai to the time­of­flight delay of a line, it is necessary to consider the transmission line behavior for de­ lay on this formula, we show the property that the minimum delay for a transmission line with reflection occurs when

Chen, Tai-Chen

355

Towards optimal allocation of computer resources: Trade-offs between uncertainty quantification, discretization and model reduction  

Science Journals Connector (OSTI)

The computational complexity of numerical models can be broken down into contributions ranging from spatial, temporal and stochastic resolution, e.g., spatial grid resolution, time step size and number of repeated simulations dedicated to quantify uncertainty. ... Keywords: Computational costs, Optimal design, Stochastic hydrology, Uncertainty quantification

Philipp C. Leube; Felipe P. J. De Barros; Wolfgang Nowak; Ram Rajagopal

2013-12-01T23:59:59.000Z

356

Modeling and Optimizing Hypertextual Search Engines Based on the Reasearch of Larry Page and Sergey Brin  

E-Print Network [OSTI]

Engines April 15, 2009 7 / 57 #12;Introduction - Section II - Outline Terms and Definitions Brief Search' or displayed back to the user in hypertextual format. mek (UVM) Search Engines April 15, 2009 9 / 57 #12;TermsModeling and Optimizing Hypertextual Search Engines Based on the Reasearch of Larry Page and Sergey

Wu, Xindong

357

A Model of Optimal Portfolio Selection under Liquidity Risk and Price Impact  

E-Print Network [OSTI]

A Model of Optimal Portfolio Selection under Liquidity Risk and Price Impact Vathana LY VATH risky asset subject to liquidity risk and price impact. In this market, an investor may transfer funds between the two assets at any discrete time. Each purchase or sale policy decision affects the price

Paris-Sud XI, Université de

358

Optimized regional and interannual variability of lightning in a global chemical transport model constrained  

E-Print Network [OSTI]

to remove their diurnal sampling bias, we construct a monthly time series of lightning flash rates for 1998, D20307, doi:10.1029/2012JD017934. 1. Introduction [2] The extreme heat in a lightning flash channelOptimized regional and interannual variability of lightning in a global chemical transport model

Jacob, Daniel J.

359

Lumped thermal model for switched reluctance motor applied to mechanical design optimization  

Science Journals Connector (OSTI)

Switched reluctance motors (SRM) are attracting much attention because of their special advantages. Generated heat, due to losses, can reduce the life time of SRMs. Therefore, taking into account thermal modeling helps to improve their performance and ... Keywords: Conduction, Convection, Motor losses, Optimal design, Switched reluctance motor, Thermal equivalent circuit

Hossein Rouhani; Jawad Faiz; Caro Lucas

2007-03-01T23:59:59.000Z

360

Optimal Production Planning Models for Parallel Batch Reactors with Sequence-dependent Changeovers  

E-Print Network [OSTI]

1 Optimal Production Planning Models for Parallel Batch Reactors with Sequence planning of parallel multi-product batch reactors with sequence-dependent changeovers, a challenging of number of products, reactors or length of the time horizon, we propose a decomposition technique based

Grossmann, Ignacio E.

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


361

PASI 2011: Process Modeling and Optimization for Energy and Sustainability Mineral Process Design for  

E-Print Network [OSTI]

PASI 2011 PASI 2011: Process Modeling and Optimization for Energy and Sustainability Mineral, high population growth and urbanization, both key metals consumption and GDP are expected to grow the environmental impact, both in per tonne of product and on total amount of emissions and reduction. #12

Grossmann, Ignacio E.

362

Modeling and Optimization of Membrane Reactors for Carbon Capture in Integrated Gasification Combined Cycle Units  

Science Journals Connector (OSTI)

Modeling and Optimization of Membrane Reactors for Carbon Capture in Integrated Gasification Combined Cycle Units ... This paper investigates the alternative of precombustion capture of carbon dioxide from integrated gasification combined cycle (IGCC) plants using membrane reactors equipped with H2-selective zeolite membranes for the water gas shift reaction. ...

Fernando V. Lima; Prodromos Daoutidis; Michael Tsapatsis; John J. Marano

2012-03-08T23:59:59.000Z

363

Modeling and Optimization of the Turbo-Compression Chiller Systems in the LCD Process  

Science Journals Connector (OSTI)

Modeling and Optimization of the Turbo-Compression Chiller Systems in the LCD Process ... The refrigerator can be divided into two parts, as shown in Figure 2: the mechanical part, consisting of a compressor, an expander or a valve, and two heat exchangers (e.g., an evaporator and a condenser); and the chemical-material part of the refrigerant cycle. ...

Changhyun Jeong; Kiwook Song; Jiyeon Nam; Chonghun Han

2012-01-16T23:59:59.000Z

364

Prerequisites: Engine Systems, Dynamic Programming and Optimal Control, MATLAB/Simulink  

E-Print Network [OSTI]

of Nonroad Diesel Engines with SCR Systems Description: To fulfill the emission legislation, modern nonroad Diesel engines are equipped with selective catalytic reduction (SCR) systems. These systems reduce NOx" in order to achieve minimal urea and fuel consumptions. The optimization problem needs to be solved

Lygeros, John

365

Concurrent Optimization of Consumer's Electrical Energy Bill and Producer's Power Generation Cost under a Dynamic Pricing  

E-Print Network [OSTI]

Concurrent Optimization of Consumer's Electrical Energy Bill and Producer's Power Generation Cost lower cost. I. INTRODUCTION There is no substitute for the status of electrical energy, which. Availability of affordable and sustainable electrical energy has been the key to prosperity and continued socio

Pedram, Massoud

366

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

367

User Guide for PV Dynamic Model Simulation Written on PSCAD Platform  

SciTech Connect (OSTI)

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

368

An Efficient Multiperiod MINLP Model for Optimal Planning of Offshore Oil and Gas Field Infrastructure  

Science Journals Connector (OSTI)

An Efficient Multiperiod MINLP Model for Optimal Planning of Offshore Oil and Gas Field Infrastructure ... Offshore oil and gas field development represents a very complex problem and involves multibillion dollar investments and profits (Babusiaux et al.(1)). ... This paper focuses on a nonconvex MINLP model for the strategic/tactical planning of the offshore oil and gas fields, which includes sufficient details to make it useful for realistic oilfield development projects, as well as for extensions to include fiscal and uncertainty considerations. ...

Vijay Gupta; Ignacio E. Grossmann

2012-04-07T23:59:59.000Z

369

Reference Model MHK Turbine Array Optimization Study within a Generic River System.  

SciTech Connect (OSTI)

Increasing interest in marine hydrokinetic (MHK) energy has spurred to significant research on optimal placement of emerging technologies to maximize energy conversion and minimize potential effects on the environment. However, these devices will be deployed as an array in order to reduce the cost of energy and little work has been done to understand the impact these arrays will have on the flow dynamics, sediment-bed transport and benthic habitats and how best to optimize these arrays for both performance and environmental considerations. An %22MHK-friendly%22 routine has been developed and implemented by Sandia National Laboratories (SNL) into the flow, sediment dynamics and water-quality code, SNL-EFDC. This routine has been verified and validated against three separate sets of experimental data. With SNL-EFDC, water quality and array optimization studies can be carried out to optimize an MHK array in a resource and study its effects on the environment. The present study examines the effect streamwise and spanwise spacing has on the array performance. Various hypothetical MHK array configurations are simulated within a trapezoidal river channel. Results show a non-linear increase in array-power efficiency as turbine spacing is increased in each direction, which matches the trends seen experimentally. While the sediment transport routines were not used in these simulations, the flow acceleration seen around the MHK arrays has the potential to significantly affect the sediment transport characteristics and benthic habitat of a resource. Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd

Johnson, Erick; Barco Mugg, Janet; James, Scott; Roberts, Jesse D.

2011-12-01T23:59:59.000Z

370

Optimizing fracture stimulation using treatment-well tiltmeters and integrated fracture modeling  

SciTech Connect (OSTI)

This paper covers the optimization of hydraulic fracture treatments in a new coalbed methane (CBM) reservoir in Wyoming. A multiwell pilot project was conducted in the Copper Ridge (CR) field to assess future development potential. Hydraulic fracture mapping was successfully performed with treatment-well tiltmeters on six wells including the first-ever used on propped treatments. The mapped fracture height was then used to calibrate the fracture model, perform on-site fracture-design changes, and optimize future fracture treatments. This paper shows how early use of fracture diagnostics can assist in the development of a new reservoir.

Mayerhofer, M.; Stutz, L.; Davis, E.; Wolhart, S. [Pinnacle Technology Houston, Houston, TX (United States)

2006-05-15T23:59:59.000Z

371

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

SciTech Connect (OSTI)

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

372

A multi-objective evolutionary algorithm-based ensemble optimizer for feature selection and classification with neural network models  

Science Journals Connector (OSTI)

In this paper, we propose a new multi-objective evolutionary algorithm-based ensemble optimizer coupled with neural network models for undertaking feature selection and classification problems. Specifically, the Modified micro Genetic Algorithm (MmGA) ... Keywords: Ensemble models, Evolutionary algorithm, Feature selection, Multi-objective optimization, Neural network classifiers

Choo Jun Tan; Chee Peng Lim; Yu-N Cheah

2014-02-01T23:59:59.000Z

373

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

374

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

375

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

376

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

377

Industrial Optimization Compact Course  

E-Print Network [OSTI]

Industrial Optimization Compact Course and Challenge Workshop Optimization plays a crucial role of the processes are typically nonlinear and dyna- mic. Thus, complex dynamic optimization or optimal control in industrial optimization. February 17­20, 2014 ·9.00­17.00 IWR ·Im Neuenheimer Feld 368 ·69120 Heidelberg www

Kirches, Christian

378

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

SciTech Connect (OSTI)

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

379

On the Design of Diploid Genetic Algorithms for Problem Optimization in Dynamic Environments  

E-Print Network [OSTI]

in a dynamic environment in nature. However, when solving DOPs, traditional GAs face a big problem design factors: the cardinality of genotypic alleles and the uncertainty in the dominance scheme. This paper investigates the effect of these two factors on the performance of diploidy genetic algorithms

Yang, Shengxiang

380

The Optimal Golf Swing An exercise in simulation of dynamic systems  

E-Print Network [OSTI]

correct handling is critical. Examples are flight-simulators and the training of operators in large power Dynamic systems have many applications, and simulators may be used for training personnel in cases where of true feeling the operators experience during the simulator training d the efficiency and accuracy

Mosegaard, Klaus

Note: This page contains sample records for the topic "dynamic optimization model" 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

IFDM modelling for optimal siting of air quality monitoring stations around five oil refineries  

Science Journals Connector (OSTI)

An IFDM modelling study has been conducted to determine the optimal siting of air quality monitoring stations around five oil refineries. The purpose of this immission monitoring network is specified in environmental legislation. The most appropriate output parameter of the IFDM model for this study is the 98th percentile of the moving 24 h averages, P98,m24h. Modelling for the optimal siting of air quality monitoring stations turned out to be different from modelling for permit granting. Of interest is not the peak value of a relevant immission parameter, but the places where this parameter is most likely to have a higher peak value compared with neighbouring places. For this study, modelling has been done for eleven years of hourly meteorological data. The eleven yearly immission fields obtained by modelling are synthesized using the minimum, median and maximum values of the P98,m24h values obtained for each receptor point. This synthesis of the modelling results was complemented with an analysis of the available immission data for the region, so that the resulting air quality monitoring network is expected to monitor the impact of all emissions, not only those emissions that are in the emission inventory used for modelling.

G. Cosemans; G. Dumont; E. Roekens; J.G. Kretzschmar

1997-01-01T23:59:59.000Z

382

Large scale molecular dynamics modeling of materials fabrication processes  

SciTech Connect (OSTI)

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

383

An API for dynamic partial evaluation under DynamoRIO  

E-Print Network [OSTI]

Dynamic optimization systems have available runtime (dynamic) data and can cross more boundaries than traditional static optimization systems in the pursuit of program transformations. However, dynamic optimization systems ...

Leger, Christopher, 1981-

2004-01-01T23:59:59.000Z

384

Observations on the Optimality Tolerance in the CAISO 33% RPS Model  

SciTech Connect (OSTI)

In 2008 Governor Schwarzenegger of California issued an executive order requiring that 33 percent of all electricity in the state in the year 2020 should come from renewable resources such as wind, solar, geothermal, biomass, and small hydroelectric facilities. This 33% renewable portfolio standard (RPS) was further codified and signed into law by Governor Brown in 2011. To assess the market impacts of such a requirement, the California Public Utilities Commission (CPUC) initiated a study to quantify the cost, risk, and timing of achieving a 33% RPS by 2020. The California Independent System Operator (CAISO) was contracted to manage this study. The production simulation model used in this study was developed using the PLEXOS software package, which allows energy planners to optimize long-term system planning decisions under a wide variety of system constraints. In this note we describe our observations on varying the optimality tolerance in the CAISO 33% RPS model. In particular, we observe that changing the optimality tolerance from .05% to .5% leads to solutions over 5 times faster, on average, producing very similar solutions with a negligible difference in overall distance from optimality.

Yao, Y; Meyers, C; Schmidt, A; Smith, S; Streitz, F

2011-09-22T23:59:59.000Z

385

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

386

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

387

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

388

Combining multi-objective optimization and bayesian model averaging to calibrate forecast ensembles of soil hydraulic models  

SciTech Connect (OSTI)

Most studies in vadose zone hydrology use a single conceptual model for predictive inference and analysis. Focusing on the outcome of a single model is prone to statistical bias and underestimation of uncertainty. In this study, we combine multi-objective optimization and Bayesian Model Averaging (BMA) to generate forecast ensembles of soil hydraulic models. To illustrate our method, we use observed tensiometric pressure head data at three different depths in a layered vadose zone of volcanic origin in New Zealand. A set of seven different soil hydraulic models is calibrated using a multi-objective formulation with three different objective functions that each measure the mismatch between observed and predicted soil water pressure head at one specific depth. The Pareto solution space corresponding to these three objectives is estimated with AMALGAM, and used to generate four different model ensembles. These ensembles are post-processed with BMA and used for predictive analysis and uncertainty estimation. Our most important conclusions for the vadose zone under consideration are: (1) the mean BMA forecast exhibits similar predictive capabilities as the best individual performing soil hydraulic model, (2) the size of the BMA uncertainty ranges increase with increasing depth and dryness in the soil profile, (3) the best performing ensemble corresponds to the compromise (or balanced) solution of the three-objective Pareto surface, and (4) the combined multi-objective optimization and BMA framework proposed in this paper is very useful to generate forecast ensembles of soil hydraulic models.

Vrugt, Jasper A [Los Alamos National Laboratory; Wohling, Thomas [NON LANL

2008-01-01T23:59:59.000Z

389

COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT  

SciTech Connect (OSTI)

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the "physics" of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited. 3a. EULAG Advances EULAG is a non-hydrostatic, parallel computational model for all-scale geophysical flows. EULAG's name derives from its two computational options: EULerian (flux form) or semi-LAGrangian (advective form). The model combines nonoscillatory forward-in-time (NFT) numerical algorithms with a robust elliptic Krylov solver. A signature feature of EULAG is that it is formulated in generalized time-dependent curvilinear coordinates. In particular, this enables grid adaptivity. In total, these features give EULAG novel advantages over many existing dynamical cores. For EULAG itself, numerical advances included refining boundary conditions and filters for optimizing model performance in polar regions. We also added flexibility to the model's underlying formulation, allowing it to work with the pseudo-compressible equation set of Durran in addition to EULAG's standard anelastic formulation. Work in collaboration with others also extended the demonstrated range of validity of soundproof models, showing that they are more broadly applicable than some had previously thought. Substantial testing of EULAG included application and extension of the Jablonowski-Williamson baroclinic wave test - an archetype of planetary weather - and further analysis of multi-scale interactions arising from collapse of temperature fronts in both the baroclinic wave test and simulations of the Held-Suarez idealized climate. These analyses revealed properties of atmospheric gravity waves not seen in previous work and further demonstrated the ability of EULAG to simulate realistic behavior over several orders of magnitude of length scales. Additional collaborative work enhanced capability for modeling atmospheric flows with adaptive moving meshes and demonstrated the ability of EULAG to move into petascale computing. 3b. CAM-EULAG Advances We have developed CAM-EULAG in collaboration with former project postdoc, now University of Cape Town Assistant Professor, Babatunde Abiodun. Initial study documented good model performance in aqua-planet simulations. In particular, we showed that the grid adaptivity (stretching) implemented in CAM-EULAG allows higher resolution in selected regions without causing anomalous behavior such as spurious wave reflection. We then used the stretched-grid version to analyze simulated extreme precipitation events in West Africa, comparing the precipitation and event environment with observed behavior. The model simulates fairly well the spatial scale and the interannual and intraseasonal variability of the extreme events, although its extreme precipitation intensity is weaker than observed. In addition, both observations and the simulations show possible forcing of extreme events by African easterly waves. 3c. Other Contributions Through our collaborations, we have made contributions to a wide range of outcomes. For research focused on terrestrial behavior, these have included (1) upwind schemes for gas dynamics, (2) a nonlinear perspective on the dynamics of the Madden-Julian Oscillation, (3) numerical realism of thermal co

Gutowski, William J.; Prusa, Joseph M.; Smolarkiewicz, Piotr K.

2012-05-08T23:59:59.000Z

390

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

391

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.

392

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

393

Lumped thermal model for switched reluctance motor applied to mechanical design optimization  

Science Journals Connector (OSTI)

Switched reluctance motors (SRM) are attracting much attention because of their special advantages. Generated heat, due to losses, can reduce the life time of SRMs. Therefore, taking into account thermal modeling helps to improve their performance and increase their life time. In this paper, a lumped thermal model of SRM based on the analogue circuit of conductive and convective thermal resistances is proposed. First the heat transfer equations were applied for modeling of each motor part as a thermal equivalent circuit. Then, the thermal modeling of whole SRM was done via assembling all these sub-circuits. For validity of the obtained model on a wide range of geometrical and structural properties of motor, apt heat transfer relations have been used. This comprehensive model is used to investigate the influence of dimensions on heat transfer in SRM. Finally, an optimal design of the stator yoke dimensions has been reached concerning the mechanical aspects without degrading electromagnetic characteristics of SRM.

Hossein Rouhani; Jawad Faiz; Caro Lucas

2007-01-01T23:59:59.000Z

394

Grey-box modeling of an ocean vessel for operational optimization  

Science Journals Connector (OSTI)

Operational optimization of ocean vessels, both off-line and in real-time, is becoming increasingly important due to rising fuel cost and added environmental constraints. Accurate and efficient simulation models are needed to achieve maximum energy efficiency. In this paper a grey-box modeling approach for the simulation of ocean vessels is presented. The modeling approach combines conventional analysis models based on physical principles (a white-box model) with a feed forward neural-network (a black-box model). Two different ways of combining these models are presented, in series and in parallel. The results of simulating several trips of a medium sized container vessel show that the grey-box modeling approach, both serial and parallel approaches, can improve the prediction of the vessel fuel consumption significantly compared to a white-box model. However, a prediction of the vessel speed is only improved slightly. Furthermore, the results give an indication of the potential advantages of grey-box models, which is extrapolation beyond a given training data set and the incorporation of physical phenomena which are not modeled in the white-box models. Finally, included is a discussion on how to enhance the predictability of the grey-box models as well as updating the neural-network in real-time.

Leifur Þ. Leifsson; Hildur Sævarsdóttir; Sven Þ. Sigurðsson; Ari Vésteinsson

2008-01-01T23:59:59.000Z

395

From the Optimizing Thermostat to a Smart Energy Management System: Models,  

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

From the Optimizing Thermostat to a Smart Energy Management System: Models, From the Optimizing Thermostat to a Smart Energy Management System: Models, Benchmark, and Insights Speaker(s): Yong Liang Date: May 1, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Janie Page Nowadays, users in the retail electricity market only need to pay a fixed rate for electricity. This strategy results in lack of coordination between demand and supply and costs significant waste. A shift from fixed rate pricing in retail markets could potentially yield many benefits. Time-varying pricing promotes the substitution of off-peak consumption for peak consumption, reducing strain on the electrical system, the need for costly and inefficient "peaker" plants, and waste in electricity delivery. However, existing research supports what common sense suggests:

396

Mathematical modelling approach for determining optimal machining parameters in turning with computer numerical control (CNC) machines  

Science Journals Connector (OSTI)

Due to advancement in the manufacturing technology the application of computer numerical control (CNC) machines have increased manifolds. The determination of machining parameters for optimal results in machining is a part of computer aided process planning. In computer numerical control (CNC) machining, determining optimum or appropriate cutting parameters can minimise machining errors such as tool breakage, tool deflection and tool wear, thus yielding a high productivity or minimum cost. Different mathematical models have been proposed by various researchers in the past for the determination of optimal machining parameters. The present paper attempt's to review the literature regarding 'machining parameter optimisation' for turning operation in CNC machines. Diverse contributing and important factors in mathematical modelling like, the economic criteria's, single and multi-pass turning, optimisation techniques and practical constraints deployed have been considered. A detailed discussion is presented regarding the topic and in the end conclusions are drawn.

Bhaskar Naithani; Santram Chauhan

2012-01-01T23:59:59.000Z

397

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

398

Dynamic Model of Hydrogen in GaN  

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

399

Impacts of Optimized Cold & Hot Deck Reset Schedules on Dual Duct VAV Systems - Theory and Model Simulation  

E-Print Network [OSTI]

Impacts of Optimized Cold & Hot Deck Reset Schedules on Dual Duct VAV Systems - Theory and Model Simulation Mingsheng Liu, Ph.D., P.E. Energy Systems Laboratory Texas A&M University College Station, Texas Abstract Optimal hot and cold deck... rate increased from 30% to 70% of the maximum flow. Introduction Simultaneous heating and cooling can be reduced sigmficantly by optimizing cold and hot deck reset schedules in dual duct constant volume systems [Liu et. a1 1994, 1995, 19961...

Liu, M.; Claridge, D. E.

1998-01-01T23:59:59.000Z

400

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

Data Warehouse Model to Support Optimized Operation and Energy Savings in Buildings  

E-Print Network [OSTI]

University College Cork (Ireland) Department of Civil and Environmental Engineering Data Warehouse Model to support Optimized Operation and Energy Savings in Buildings Paul Stack, Brian Cahill, Farhan Manzoor, Prof. Karsten Menzel 20... October 2011 page 1ICEBO 2011 Session 10 - Brian Cahill University College Cork (Ireland) Department of Civil and Environmental Engineering ICT for Optimised Building Operation (ITOBO) 20 October 2011 ICEBO 2011 Session 10 - Brian Cahill page 2...

Stack, P.; Cahill, B.; Manzoor, F.; Menzel, K.

2011-01-01T23:59:59.000Z

402

Optimization of a Chilled Water Plant Using a Forward Plant Model  

E-Print Network [OSTI]

Optimization of a chilled water plant without storage using a forward plant model Zhiqin Zhanga, PhD William D. Turnera, PhD, PE Qiang Chena, PE Chen Xub, PE Song Denga, PE... at a given setpoint. This setpoint is manually adjusted to be between 25 psid (172 kPa) and 48 psid (331 kPa) all year round to ensure there are no hot complaints from terminals. The cooling tower staging control in place is to stage the number...

Zhang, Z.; Turner, W. D.; Chen, Q.; Xu, C.; Deng, S.

2010-01-01T23:59:59.000Z

403

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

404

Optimal Velocity Profile Generation for given Acceleration Limits; The Half-Car Model Case  

E-Print Network [OSTI]

average curvature, or a path of minimum combined cost. Since the dynamics of the vehicle are not included. Velenis and P. Tsiotras Georgia Institute of Technology School of Aerospace Engineering, Atlanta, GA, USA is an extension of [1] where a point-mass model of the vehicle was used. The acceleration envelope of the vehicle

Tsiotras, Panagiotis

405

Utility Accrual Real-Time Scheduling with Energy Bounds In this paper, we consider timeliness and energy optimization in battery-powered, dynamic  

E-Print Network [OSTI]

. An important technique used for optimizing the energy consumption of real-time embedded systems is dynamic in the physical world). Further, they are energy-critical, as they must operate on battery, with finite energy and minimizing the system's energy consumption, and not just the CPU's energy consumption. Moreover, such systems

Ravindran, Binoy

406

Optimizing Higher-Order Lagrangian Perturbation Theory for Standard CDM and BSI models  

E-Print Network [OSTI]

We investigate the performance of Lagrangian perturbation theory up to the second order for two scenarios of cosmological large-scale structure formation, SCDM (standard cold dark matter) and BSI (broken scale invariance). The latter model we study as a representative of COBE-normalized CDM models which fit the small-scale power of galaxy surveys. In this context we optimize the performance of the Lagrangian perturbation schemes by smoothing the small-scale fluctuations in the initial data. The results of the so obtained Lagrangian mappings are computed for a set of COBE-normalized SCDM and BSI initial data of different sizes and at different times. We compare these results against those obtained with a numerical PM-code. We find an excellent performance of the optimized Lagrangian schemes down to scales close to the correlation length. This is explained by the counterintuitive fact that nonlinearities in the model can produce more small-scale power, if initially such power is removed. The optimization scheme can be expressed in a way which is independent of the type of fluctuation spectrum and of the size of the simulations.

Arno G. Weiss; Stefan Gottloeber; Thomas Buchert

1995-05-24T23:59:59.000Z

407

FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture  

SciTech Connect (OSTI)

A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and pre-damping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

Sun, Yipeng; /SLAC

2012-05-11T23:59:59.000Z

408

An optimized model and test of the China's first high temperature parabolic trough solar receiver  

SciTech Connect (OSTI)

The vacuum solar receiver is the key component of a parabolic trough solar plant, which plays a prominent role in the gross system efficiency. Recently, China's first high temperature vacuum receiver, Sanle-3 HCE, has been developed and produced by Southeast University and Sanle Electronic Group. Before being utilized in China's first parabolic trough solar plant, accurately estimating the thermal properties of this new receiver is important. This paper first establishes and optimizes a 1-D theoretical model at Matlab program to compute the receiver's major heat loss through glass envelope, and then systematically analyzes the major influence factors of heat loss. With the laboratorial steady state test stand, the heat losses of both good vacuum and non-vacuum Sanle-3 receivers were surveyed. Comparison shows the original 1-D model agrees with the ends covered test while remarkably deviating from end exposed test. For the purpose of identifying the influence of receiver's end to total heat loss, an additional 3-D model is built by CFD software to further investigate the different heat transfer processes of receiver's end components. The 3-D end model is verified by heating power and IR temperature distribution images in the test. Combining the optimized 1-D model with the new 3-D end model, the comparison with test data shows a good accordance. At the same time the heat loss curve and emittance curve of this new receiver are given and compared with those of several other existing receivers as references. (author)

Gong, Guangjie; Huang, Xinyan; Wang, Jun; Hao, Menglong [Southeast University, Nanjing (China)

2010-12-15T23:59:59.000Z

409

On the determination of single-crystal plasticity parameters by diffraction: optimization of a polycrystalline plasticity model using a genetic algorithm  

Science Journals Connector (OSTI)

A genetic algorithm was used to successfully optimize the work hardening coefficients of a polycrystalline plasticity model.

Skippon, T.

2012-07-14T23:59:59.000Z

410

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

411

An Optimal Solution to a General Dynamic Jet Fuel Hedging Problem  

E-Print Network [OSTI]

hedging against jumps in the price of jet fuel and placing bets that the price will rise, lowering the overall cost of jet fuel. We model the commodity price using an unobservable two-factor model that allows for a large portion of an airline's operating expenses and when fuel prices rise dramatically, airlines cannot

Powell, Warren B.

412

Optimization Online - Topology optimization of a mechanical ...  

E-Print Network [OSTI]

Aug 26, 2005 ... Topology optimization of a mechanical component subject to dynamical constraints. Sonia Calvel (sonia.calvel ***at*** voila.fr)

Sonia Calvel

2005-08-26T23:59:59.000Z

413

Intensity-Modulated Radiotherapy Optimization in a Quasi-Periodically Deforming Patient Model  

SciTech Connect (OSTI)

Purpose: To present the implementation of a probability-based, four-dimensional (4D) intensity-modulated radiotherapy (IMRT) planning approach that explicitly optimizes the accumulated dose to moving tissue, estimated using the patient's probability density function (pdf) of respiratory motion. This is termed 'optimization in tissue's-eye-view'. Methods and Materials: The method incorporates 4D Monte Carlo dose calculation in multiple geometries of a respiratory-correlated CT dataset. The instance doses are weighted according to the breathing pdf and accumulated in a common reference geometry, which involves dose warping based on deformable registration. The algorithm produces deliverable multileaf collimator segments and was tested on a sample lung cancer patient dataset with large target excursion. Accumulated doses of the moving target and organs at risk of this plan were compared with those of corresponding margin-based static IMRT plans for free-breathing and gated treatment, as well as target tracking. Results: Target tracking provided best target coverage. Both the presented 4D IMRT approach for free-breathing treatment and gated treatment gave similar results for target coverage and lung dose, with significantly better target coverage than the margin-based static IMRT plan for free-breathing treatment. Conclusions: The presented 4D planning concept offers an alternative to gating by providing the optimal dose for free-breathing IMRT treatment. Although the focus of this study was 4D lung planning, the approach can be generally applied for IMRT optimization in randomly deforming patient models.

Soehn, Matthias, E-mail: Matthias.Soehn@med.uni-tuebingen.d [Section for Biomedical Physics, University Hospital for Radiation Oncology, Tuebingen (Germany); Weinmann, Martin [Department of Radiotherapy, University Hospital for Radiation Oncology, Tuebingen (Germany); Alber, Markus [Section for Biomedical Physics, University Hospital for Radiation Oncology, Tuebingen (Germany)

2009-11-01T23:59:59.000Z

414

Fast Protein Folding in the Hydrophobic-hydrophilic Model Within Three-eights of Optimal (Extended Abstract)  

E-Print Network [OSTI]

Fast Protein Folding in the Hydrophobic-hydrophilic Model Within Three-eights of Optimal (Extended for the protein folding problem in the hydrophobic- hydrophilic model, Dill (1985). To our knowledge, our al for this model, Dill (1994). The hydrophobic-hydrophilic model abstracts the dominant force of protein folding

Istrail, Sorin

415

Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant  

SciTech Connect (OSTI)

This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve these two formulations were developed and validated. For a given OSP problem the computation efficiency largely depends on the “size” of the problem. Initially a simplified 1-D gasifier model assuming axial and azimuthal symmetry was used to test out various OSP algorithms. Finally these algorithms were used to design the optimal sensor network for condition monitoring of IGCC gasifier refractory wear and RSC fouling. The sensors type and locations obtained as solution to the OSP problem were validated using model based sensing approach. The OSP algorithm has been developed in a modular form and has been packaged as a software tool for OSP design where a designer can explore various OSP design algorithm is a user friendly way. The OSP software tool is implemented in Matlab/Simulink© in-house. The tool also uses few optimization routines that are freely available on World Wide Web. In addition a modular Extended Kalman Filter (EKF) block has also been developed in Matlab/Simulink© which can be utilized for model based sensing of important process variables that are not directly measured through combining the online sensors with model based estimation once the hardware sensor and their locations has been finalized. The OSP algorithm details and the results of applying these algorithms to obtain optimal sensor location for condition monitoring of gasifier refractory wear and RSC fouling profile are summarized in this final report.

Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo

2012-12-31T23:59:59.000Z

416

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

417

MINLP model for optimal biocide dosing and maintenance scheduling of seawater cooled plants  

Science Journals Connector (OSTI)

Abstract Nowadays many countries in arid regions around the world suffer from severe water shortages; this situation is steadily becoming a global concern as water resources are being depleted. In this regard, strategies that a few decades ago were not feasible are becoming interesting alternatives; one of them is the use of seawater as cooling fluid in chemical plants. This alternative, however, presents problems in the plant operation, including a rapid biofilm growth (biofouling) that reduces the heat transfer efficiency. To control the biofouling, the use of biocides (usually chlorine) and periodical mechanical maintenances are implemented. In this work a mathematical programming model is presented for the optimal planning of biocide dosing and mechanical maintenance scheduling. The model considers the biocide kinetics along the network, its dependence with temperature and its interaction with the biofilm thickness. The model uses disjunctive programming to select the optimal maintenance scenario, allowing for different levels of biofilm thickness that depend on the plant schedule. The model also includes environmental constraints to prevent the discharge of streams with potentially dangerous loads of chemicals. These constraints include a limit for the concentration of biocide and the end of pipe chemical treatment. The objective function is to minimize the total annual cost, including the cost for the biocide, chemicals used for end of pipe treatment and maintenance. To show the model applicability, a case study for an integrated power/desalination plant cooled with seawater is solved. Several scenarios were tested including daily, biweekly, monthly and bimonthly biocide and end of pipe treatment chemical dosing, and mechanical maintenances from one to up to six times per year. The results indicate that recurrent dosing policies, either biweekly or monthly for operational simplicity, along with a maximum of three treatments per year provide an optimal scenario.

Fabricio Nápoles-Rivera; Abdullah Bin Mahfouz; Arturo Jiménez-Gutiérrez; Mahmoud M. El-Halwagi; José María Ponce-Ortega

2012-01-01T23:59:59.000Z

418

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

419

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

420

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

O-regime dynamics and modeling in Tore Supra  

SciTech Connect (OSTI)

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

422

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

423

E-AMOM: An Energy-Aware Modeling and Optimization Methodology for Scientific Applications on Multicore Systems  

E-Print Network [OSTI]

power consumption of the scientific applications. Further, we optimize our applications based upon insights provided by the performance models to reduce runtime of the applications. Our methods and techniques are able to save up to 18% in energy...

Lively, Charles

2012-07-16T23:59:59.000Z

424

Optimal Evolutionary Wind Turbine Placement in Wind Farms Considering New Models of Shape, Orography and Wind Speed Simulation  

Science Journals Connector (OSTI)

In this paper we present a novel evolutionary algorithm for optimal positioning of wind turbines in wind farms. We consider a realistic model for the wind farm, which includes orography, shape of the wind farm, s...

B. Saavedra-Moreno; S. Salcedo-Sanz…

2011-01-01T23:59:59.000Z

425

Transmission Line Structure Spotting and Optimization within a Defined Transmission Line Routing Centerline Using Non-Linear Programming Models  

E-Print Network [OSTI]

and optimize structure heights for overhead transmission lines. The modeling tool will address common problems in determining overhead transmission line structure heights and locations. Some of the common problems consist of structure locations often having...

Cockrum, Joshua W.

2010-05-14T23:59:59.000Z

426

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

427

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

428

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

429

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

SciTech Connect (OSTI)

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

430

An agent based modeling approach for determining optimal price-rebate schemes  

Science Journals Connector (OSTI)

Delayed incentives in the form of cash mail-in rebates have become very popular. While some research has been conducted on consumer perception and behavior toward rebates, little research has been undertaken with respect to a seller’s optimal rebate strategy. We use an agent-based modeling approach for jointly determining optimal price and rebate value. This approach has been previously applied to pricing and can capture some aspects of the problem which are difficult to analyze using traditional mathematical modeling. The model indicates that rebates are much more profitable when their values are jointly determined with price. In addition, the profitability of rebates at a given time depends on past consumers’ experience with rebates and that consumers’ memory of their past rebate redemption behavior plays an important role in determining the profitability of rebates. Also, the analysis shows that agent-based modeling may provide an alternative method for analyzing problems in which interactions between participants in the systems, i.e. consumers, sellers, and regulating agencies, are important in determining the overall behavior of the system.

Moutaz Khouja; Mirsad Hadzikadic; Muhammad Adeel Zaffar

2008-01-01T23:59:59.000Z

431

EXTENDING THE REALM OF OPTIMIZATION FOR COMPLEX SYSTEMS: UNCERTAINTY, COMPETITION, AND DYNAMICS  

SciTech Connect (OSTI)

Research reported addressed these topics: the development of analytical and algorithmic tools for distributed computation of Nash equilibria; synchronization in mean-field oscillator games, with an emphasis on learning and efficiency analysis; questions that combine learning and computation; questions including stochastic and mean-field games; modeling and control in the context of power markets.

Shanbhag, Uday V; Basar, Tamer; Meyn, Sean; Mehta, Prashant

2013-10-08T23:59:59.000Z

432

Global Optimization of Chemical Reactors and Kinetic Optimization  

E-Print Network [OSTI]

Model; 3-D; Monolith; Reactor; Optimization Introduction TheAngeles Global Optimization of Chemical Reactors and KineticGlobal Optimization of Chemical Reactors and Kinetic

ALHUSSEINI, ZAYNA ISHAQ

2013-01-01T23:59:59.000Z

433

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

434

Wireless Sensor Technology to Optimize the Occupant's Dynamic Demand Pattern Within the Building  

E-Print Network [OSTI]

). It is necessary to come with new application of WSN, therefore a close look was needed into possible additional functionality of WSN in regards to human behaviour. Arens (Arens et al. 2005) proposed a distributed sensor network for office rooms. At room scale... using a whole building model programmed in the Simulink HAMBase environment. In contrary to earlier research by (Zhang et al. 2009), this study takes into account the real occupancy profiles, the appliances use, lighting profiles and the energy needed...

Zeiler, W.; Boxem, G.; Maaijen, R.

2012-01-01T23:59:59.000Z

435

Development of an entrained flow gasifier model for process optimization study  

SciTech Connect (OSTI)

Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.

Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L. [Consorzio Pisa Ric, Pisa (Italy). Div Energia Ambiente

2009-10-15T23:59:59.000Z

436

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

437

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

438

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

439

Ultrafast Structural Dynamics in Combustion Relevant Model Systems  

SciTech Connect (OSTI)

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

440

A Technical Review on Biomass Processing: Densification, Preprocessing, Modeling and Optimization  

SciTech Connect (OSTI)

It is now a well-acclaimed fact that burning fossil fuels and deforestation are major contributors to climate change. Biomass from plants can serve as an alternative renewable and carbon-neutral raw material for the production of bioenergy. Low densities of 40–60 kg/m3 for lignocellulosic and 200–400 kg/m3 for woody biomass limits their application for energy purposes. Prior to use in energy applications these materials need to be densified. The densified biomass can have bulk densities over 10 times the raw material helping to significantly reduce technical limitations associated with storage, loading and transportation. Pelleting, briquetting, or extrusion processing are commonly used methods for densification. The aim of the present research is to develop a comprehensive review of biomass processing that includes densification, preprocessing, modeling and optimization. The specific objective include carrying out a technical review on (a) mechanisms of particle bonding during densification; (b) methods of densification including extrusion, briquetting, pelleting, and agglomeration; (c) effects of process and feedstock variables and biomass biochemical composition on the densification (d) effects of preprocessing such as grinding, preheating, steam explosion, and torrefaction on biomass quality and binding characteristics; (e) models for understanding the compression characteristics; and (f) procedures for response surface modeling and optimization.

Jaya Shankar Tumuluru; Christopher T. Wright

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic optimization model" 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

Modeling Resource, Infrastructure, and Policy Cost Layers for Optimizing Renewable Energy Investment and Deployment  

SciTech Connect (OSTI)

This paper presents a framework for creating a common spatial canvass that can bring together considerations of resource availability, infrastructure reliability, and development costs while strategizing renewable energy investment. We describe the underlying models and methodologies that annotate an investment plan for potential sites over a time-period with costs and constraints which may be imposed on distance from infrastructure, system impact on infrastructure, and policy incentives. The framework is intended as an enabler for visualization, optimization and decision making across diverse dimensions while searching for lucrative investment-plans.

Sukumar, Sreenivas R [ORNL] [ORNL; Olama, Mohammed M [ORNL] [ORNL; Shankar, Mallikarjun [ORNL] [ORNL; Hadley, Stanton W [ORNL] [ORNL; Nutaro, James J [ORNL] [ORNL; Protopopescu, Vladimir A [ORNL] [ORNL; Malinchik, Sergey [Lockheed Martin Corporation] [Lockheed Martin Corporation; Ives, Barry [Lockheed Martin Corporation] [Lockheed Martin Corporation

2010-01-01T23:59:59.000Z

442

Optimization and modeling studies for obtaining high injection efficiency at the Advanced Photon Source.  

SciTech Connect (OSTI)

In recent years, the optics of the Advanced Photon Source storage ring has evolved to a lower equilibrium emittance (2.5 nm-rad) at the cost of stronger sextupoles and stronger nonlinearities, which have reduced the injection efficiency from the virtual 100% of the high emittance mode. Over the years we have developed a series of optimizations, measurements, and modeling studies of the injection process, which allows us to obtain or maintain low injection losses. The above will be described along with the injection configuration.

Emery, L.; APS Operations Division

2005-01-01T23:59:59.000Z

443

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

444

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

445

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

446

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

447

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

448

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

449

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.

450

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

451

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

452

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

453

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

454

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

455

Dynamic modelling and simulation of a polymer electrolyte membrane fuel cell used in vehicle considering heat transfer effects  

Science Journals Connector (OSTI)

Fuel cell technology is recently becoming one of the most interesting fields for the car companies to invest in. This interest is because of their high efficiency and zero environmental pollution. Polymer electrolyte membrane fuel cells are the most appropriate type of fuel cells for use in vehicles due to their low performance temperature and high power density. Air and fuel mass flow rate and partial pressure fuel cell stack temperature relative humidity of fuel cellmembrane and heat and water management are the effective parameters of fuel cellpower systems. Good transient behavior is one of the important factors that affect the success of fuel cell vehicles. In order to avoid stack voltage drop during transient condition the control system of fuel cell vehicle is required to preserve optimal temperature membrane hydration and partial pressure of reactants across the membrane. In this paper we developed a dynamic model for fuel cellpower system. The compressor dynamic supply and return manifold filling dynamics (anode and cathode) cooling system dynamic membrane hydration and time-evolving reactant partial pressure are the most significant parameters in transient and steady state of system. The effects of membrane humidity varying inlet air pressure and compressor performance condition on the generated power are studied in this paper.

S. M. Hosseini; A. H. Shamekhi; A. Yazdani

2012-01-01T23:59:59.000Z

456

Stochastic Dynamic Programming and Stochastic Fluid-Flow Models in the Design and Analysis of Web-Server Farms  

E-Print Network [OSTI]

A Web-server farm is a specialized facility designed specifically for housing Web servers catering to one or more Internet facing Web sites. In this dissertation, stochastic dynamic programming technique is used to obtain the optimal admission...

Goel, Piyush

2010-10-12T23:59:59.000Z

457

A computer model for optimizing the location of natural gas fueling stations  

Science Journals Connector (OSTI)

Abstract High levels of fine particulate matter and ozone in many major cities are causing increased respiratory problems, increased asthma attacks and premature death. Natural gas vehicles have been reported to emit up to 95% less particulate matter than diesel powered vehicles and up to 90% less ozone-producing carbon monoxide and reactive hydrocarbons. The adoption of natural gas vehicles, therefore, could play a large role in improving air quality in many cities. Because of the many costs associated with the introduction of a new fueling infrastructure, optimum distribution of fueling stations will play a major role in widespread use of natural gas vehicles, especially in the early stages of market penetration. A model was developed that can be used to optimize fueling station placement-based on traffic volume using a Monte Carlo algorithm. In particular, the Monte Carlo method allows for the placement of the fueling stations based upon their proximity to high volume traffic flow and the placement of all the fueling stations are optimized simultaneously. Traffic volume data from Pittsburgh, PA was used in the model simulations.

T.L. Kerzmann; G.A. Buxton; J. Preisser

2014-01-01T23:59:59.000Z

458

DHV water pumping optimization Simon van Mourik1  

E-Print Network [OSTI]

Chapter 6 DHV water pumping optimization Simon van Mourik1 Joris Bierkens2 Hans Stigter1 Martijn for optimizing a drinking water network over a horizon of 48 hours, given variable water demands, energy prices and constraints on the pumping strategy and water levels in the reservoirs. Both the dynamic model and goal

Rottschäfer, Vivi

459

Optimization For Grade Transitions In Polyethylene Solution Polymerization  

E-Print Network [OSTI]

Optimization For Grade Transitions In Polyethylene Solution Polymerization Jun Shi1, Intan Hamdan2 Engineering Carnegie Mellon University 2The Dow Chemical Company #12;Dynamic Optimization Models Grade Transition for LLDPE · Continuous Stirred-Tank Reactor (CSTR) (represents two actual processes) · Assume

Grossmann, Ignacio E.

460

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

Note: This page contains sample records for the topic "dynamic optimization model" 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

Mothproofing of wool fabric utilizing ZnO nanoparticles optimized by statistical models  

Science Journals Connector (OSTI)

Abstract Wool with high strength, elasticity, and resiliency has good dye-ability and comfort however could be digested by keratinolytic enzymes. In this research, wool fabric pre-treated with BTCA and then treated with nano ZnO. The treated fabrics showed mothproofing activity against the larvae of carpet beetle, Anthrenus verbasci, as feeding protein fibers. The role of both BTCA and nano ZnO concentrations on mothproofing properties of the wool fabric were optimized using statistical model of response surface methodology (RSM). Mothproofing was investigated through assessing wool weight loss during feeding by A. verbasci. The analysis of variance (ANOVA) was utilized to obtain the optimum models for wool with mothproofing properties. The damages on the wool surface confirmed with scanning electron microscopy and digital camera images. Further transmission and absorbance spectra approved the UV protection properties of the nano ZnO treated wool in both UVA and UVB.

Ali Nazari; Majid Montazer; Mehdi Dehghani-Zahedani

2014-01-01T23:59:59.000Z

462

Model-based optimization of economical grade changes for the Borealis Borstar® polyethylene plant  

Science Journals Connector (OSTI)

Economical grade changes are considered for a Borealis Borstar® polyethylene plant model, incorporating two slurry-phase reactors, one gas-phase reactor and a recycle area with three distillation columns. The model is constructed in the Modelica language and the JModelica.org platform is used for optimization. The cost function expresses the economical profit during a grade change and is formulated using on-grade intervals for seven polymer quality variables such as melt index, density and reactor split factors. Additionally, incentives to produce polymer with quality variables on grade target values, not only inside grade intervals, are added. Twelve inflows and three purge flows are used as decision variables. Two grade changes are thoroughly reviewed, showing the effect of using a cost function that regards plant economy. Resulting trajectories can be divided into three phases with distinguishing features, and the synchronization of inflows and usage of recycle area off-gas flows are important in the grade changes.

Per-Ola Larsson; Johan Åkesson; Niclas Carlsson; Niklas Andersson

2012-01-01T23:59:59.000Z

463

Optimal control theory with arbitrary superpositions of waveforms  

E-Print Network [OSTI]

Standard optimal control methods perform optimization in the time domain. However, many experimental settings demand the expression of the control signal as a superposition of given waveforms. Since this type of constraint is not time-local, Optimal Control Theory cannot be used without modifications. Simplex methods, used as a substitute in this case, tend to be less efficient and less reliable than Optimal Control Theory. In this paper, we present an extension to Optimal Control Theory which allows gradient-based optimization for superpositions of arbitrary waveforms. Its key is the use of the Moore-Penrose pseudoinverse as an efficient means of transforming from a time-local to a waveform-based description. To illustrate this optimization technique, we study the parametrically driven harmonic oscillator as model system and reduce its energy, considering both Hamiltonian dynamics and open-system dynamics. We demonstrate the viability and efficiency of the method for these test cases.

Selina Meister; Jürgen T. Stockburger; Rebecca Schmidt; Joachim Ankerhold

2014-08-27T23:59:59.000Z

464

Optimized multicomponent vs. classical geothermometry: Insights from modeling studies at the Dixie Valley geothermal area  

Science Journals Connector (OSTI)

Abstract A new geothermometry approach is explored, incorporating multicomponent geothermometry coupled with numerical optimization to provide more confident estimates of geothermal reservoir temperatures when results of classical geothermometers are inconsistent. This approach is applied to geothermal well and spring waters from the Dixie Valley geothermal area (Nevada), to evaluate the influence of salt brines mixing and dilution of geothermal fluids on calculated temperatures. The main advantage of the optimized multicomponent method over classical geothermometers is its ability to quantify the extent of dilution and gas loss experienced by a geothermal fluid, and to optimize other poorly constrained or unknown parameters (such as Al and Mg concentrations), allowing the reconstruction of the deep reservoir fluid composition and therefore gaining confidence in reservoir temperatures estimations. Because the chemical evolution of deep geothermal fluids is a combination of multiple time-dependent processes that take place when these fluids ascend to the surface, reactive transport modeling is used to assess constraints on the application of solute geothermometers. Simulation results reveal that Al and Mg concentrations of ascending fluids are sensitive to mineral precipitation–dissolution affecting reservoir temperatures inferred with multicomponent geothermometry. In contrast, simulations show that the concentrations of major elements such as Na, K, and SiO2 are less sensitive to re-equilibration. Geothermometers based on these elements give reasonable reservoir temperatures in many cases, except when dilution or mixing with saline waters has taken place. Optimized multicomponent geothermometry yields more representative temperatures for such cases. Taking into account differences in estimated temperatures, and chemical compositions of the Dixie Valley thermal waters, a conceptual model of two main geothermal reservoirs is proposed. The first reservoir is located along the Stillwater range normal fault system and has an estimated temperature of 240–260 °C. It covers the area corresponding to the geothermal field but could extend towards the south-west where deep temperatures of 200–225 °C are estimated. The second reservoir has an estimated temperature of 175–190 °C and extends from well 62-21 to northeastern Hyder, Lower Ranch, Fault Line, and Jersey springs.

L. Peiffer; C. Wanner; N. Spycher; E.L. Sonnenthal; B.M. Kennedy; J. Iovenitti

2014-01-01T23:59:59.000Z

465

Performance Modeling and Optimization of a High Energy CollidingBeam Simulation Code  

SciTech Connect (OSTI)

An accurate modeling of the beam-beam interaction is essential to maximizing the luminosity in existing and future colliders. BeamBeam3D was the first parallel code that can be used to study this interaction fully self-consistently on high-performance computing platforms. Various all-to-all personalized communication (AAPC) algorithms dominate its communication patterns, for which we developed a sequence of performance models using a series of micro-benchmarks. We find that for SMP based systems the most important performance constraint is node-adapter contention, while for 3D-Torus topologies good performance models are not possible without considering link contention. The best average model prediction error is very low on SMP based systems with of 3% to 7%. On torus based systems errors of 29% are higher but optimized performance can again be predicted within 8% in some cases. These excellent results across five different systems indicate that this methodology for performance modeling can be applied to a large class of algorithms.

Shan, Hongzhang; Strohmaier, Erich; Qiang, Ji; Bailey, David H.; Yelick, Kathy

2006-06-01T23:59:59.000Z

466

A detailed MILP optimization model for combined cooling, heat and power system operation planning  

Science Journals Connector (OSTI)

Abstract A detailed optimization model is presented for planning the short-term operation of combined cooling, heat and power (CCHP) energy systems. The purpose is, given the design of a cogeneration system, to determine an operating schedule that minimizes the total operating and maintenance costs minus the revenue due to the electricity sold to the grid, while taking into account time-varying loads, tariffs and ambient conditions. The model considers the simultaneous use of different prime movers (generating electricity and heat), boilers, compression heat pumps and chillers, and absorption chillers to satisfy given electricity, heat and cooling demands. Heat and cooling load can be stored in storage tanks. Units can have one or two operative variables, highly nonlinear performance curves describing their off-design behavior, and limitations or penalizations affecting their start-up/shut-down operations. To exploit the effectiveness of state-of-the-art Mixed Integer Linear Program (MILP) solvers, the resulting Mixed Integer Nonlinear Programming (MINLP) model is converted into a MILP by appropriate piecewise linear approximation of the nonlinear performance curves. The model, written in the AMPL modeling language, has been tested on several plant test cases. The computational results are discussed in terms of the quality of the solutions, the linearization accuracy and the computational time.

Aldo Bischi; Leonardo Taccari; Emanuele Martelli; Edoardo Amaldi; Giampaolo Manzolini; Paolo Silva; Stefano Campanari; Ennio Macchi

2014-01-01T23:59:59.000Z

467

Optimization of a Sea Ice Model Using Basinwide Observations of Arctic Sea Ice Thickness, Extent, and Velocity  

E-Print Network [OSTI]

datasets. 1. Introduction Sea ice is important to the climate system because it insulates the cold polarOptimization of a Sea Ice Model Using Basinwide Observations of Arctic Sea Ice Thickness, Extent 2004, in final form 27 June 2005) ABSTRACT A stand-alone sea ice model is tuned and validated using

Feltham, Daniel

468

Multi-objective optimization for bus body with strength and rollover safety constraints based on surrogate models  

Science Journals Connector (OSTI)

It is important to consider the performances of lightweight, stiffness, strength and rollover safety when designing a bus body. In this paper, the finite element (FE) analysis models including strength, stiffness and rollover crashworthiness of a bus ... Keywords: Bus body, Finite element analysis, Multi-objective optimization, Surrogate model

Ruiyi Su; Liangjin Gui; Zijie Fan

2011-09-01T23:59:59.000Z

469

Systems Modeling and Analysis Industrial Engineers are interested in optimizing the design and operation of complex systems  

E-Print Network [OSTI]

and operation of complex systems composed of people and machines using information, materials and energySystems Modeling and Analysis Industrial Engineers are interested in optimizing the design to produce goods and services. Analyzing such systems with information-driven models is an essential step

Dyer, Bill

470

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.

471

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

472

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

473

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

474

Optimization of numerical weather/wave prediction models based on information geometry and computational techniques  

Science Journals Connector (OSTI)

The last years a new highly demanding framework has been set for environmental sciences and applied mathematics as a result of the needs posed by issues that are of interest not only of the scientific community but of today's society in general: global warming renewable resources of energy natural hazards can be listed among them. Two are the main directions that the research community follows today in order to address the above problems: The utilization of environmental observations obtained from in situ or remote sensing sources and the meteorological-oceanographic simulations based on physical-mathematical models. In particular trying to reach credible local forecasts the two previous data sources are combined by algorithms that are essentially based on optimization processes. The conventional approaches in this framework usually neglect the topological-geometrical properties of the space of the data under study by adopting least square methods based on classical Euclidean geometry tools. In the present work new optimization techniques are discussed making use of methodologies from a rapidly advancing branch of applied Mathematics the Information Geometry. The latter prove that the distributions of data sets are elements of non-Euclidean structures in which the underlying geometry may differ significantly from the classical one. Geometrical entities like Riemannian metrics distances curvature and affine connections are utilized in order to define the optimum distributions fitting to the environmental data at specific areas and to form differential systems that describes the optimization procedures. The methodology proposed is clarified by an application for wind speed forecasts in the Kefaloniaisland Greece.

2014-01-01T23:59:59.000Z

475

The use of least squares methods in functional optimization of energy use prediction models  

Science Journals Connector (OSTI)

The least squares method (LSM) is used to optimize the coefficients of a closed-form correlation that predicts the annual energy use of buildings based on key envelope design and thermal parameters. Specifically annual energy use is related to a number parameters like the overall heat transfer coefficients of the wall roof and glazing glazing percentage and building surface area. The building used as a case study is a previously energy-audited mosque in a suburb of Kuwait City Kuwait. Energy audit results are used to fine-tune the base case mosque model in the VisualDOE{trade mark serif} software. Subsequently 1625 different cases of mosques with varying parameters were developed and simulated in order to provide the training data sets for the LSM optimizer. Coefficients of the proposed correlation are then optimized using multivariate least squares analysis. The objective is to minimize the difference between the correlation-predicted results and the VisualDOE-simulation results. It was found that the resulting correlation is able to come up with coefficients for the proposed correlation that reduce the difference between the simulated and predicted results to about 0.81%. In terms of the effects of the various parameters the newly-defined weighted surface area parameter was found to have the greatest effect on the normalized annual energy use. Insulating the roofs and walls also had a major effect on the building energy use. The proposed correlation and methodology can be used during preliminary design stages to inexpensively assess the impacts of various design variables on the expected energy use. On the other hand the method can also be used by municipality officials and planners as a tool for recommending energy conservation measures and fine-tuning energy codes.

2012-01-01T23:59:59.000Z

476

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

477

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

478

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

SciTech Connect (OSTI)

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

479

Optimal Boussinesq model for shallow-water waves interacting with a microstructure  

Science Journals Connector (OSTI)

In this paper, we consider the propagation of water waves in a long-wave asymptotic regime, when the bottom topography is periodic on a short length scale. We perform a multiscale asymptotic analysis of the full potential theory model and of a family of reduced Boussinesq systems parametrized by a free parameter that is the depth at which the velocity is evaluated. We obtain explicit expressions for the coefficients of the resulting effective Korteweg–de Vries (KdV) equations. We show that it is possible to choose the free parameter of the reduced model so as to match the KdV limits of the full and reduced models. Hence the reduced model is optimal regarding the embedded linear weakly dispersive and weakly nonlinear characteristics of the underlying physical problem, which has a microstructure. We also discuss the impact of the rough bottom on the effective wave propagation. In particular, nonlinearity is enhanced and we can distinguish two regimes depending on the period of the bottom where the dispersion is either enhanced or reduced compared to the flat bottom case.

Josselin Garnier; Roberto A. Kraenkel; André Nachbin

2007-10-12T23:59:59.000Z

480

Stochastic Modeling for Uncertainty Analysis and Multiobjective Optimization of IGCC System with Single-Stage Coal Gasification  

Science Journals Connector (OSTI)

The work initially focuses on developing a computational fluid dynamics (CFD) model for the single-stage coal gasifier, which is a part of the IGCC system. ... Medium pressure (MP) steam is produced from the heat liberated from this reaction. ...

Yogendra Shastri; Urmila Diwekar

2010-11-22T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic optimization model" 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

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

482

Low Rank Coal Optimization  

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

Low Rank Coal Optimization Low Rank Coal Optimization NETL Office of Research and Development Project Number: FWP-2012.03.03 Task 4 Project Description NETL's in-house research team is using an integrated approach to combine theory, computational modeling, experiment, and industrial input to develop physics-based methods, models, and tools to support the development and deployment of advanced gasification based devices and systems. The activities in this effort include developing and applying computational and modeling tools to simulate complex flows in applications such as transport or entrained flow gasifiers. TRIG Model Development - The primary objective of this work is to develop a hierarchy of models for numerical simulations of TRIG co-feed conditions that span fast running reduced order models (ROM's) to high fidelity multiphase computational fluid dynamics (CFD) models. Each model will have uncertainty quantification associated with its predictions to allow a user to choose a model based on the trade-offs between computational speed and uncertainty in the predictions.

483

Dynamic optimization with CasADi* Joel Andersson1 and Johan Akesson2 and Moritz Diehl1  

E-Print Network [OSTI]

models formulated in the algebraic modeling language AMPL or the physical modeling language Modelica

484

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

485

DYNAMICAL MODEL FOR THE ZODIACAL CLOUD AND SPORADIC METEORS  

SciTech Connect (OSTI)

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

486

Modeling and optimization of single-pass laser amplifiers for high-repetition-rate laser pulses  

SciTech Connect (OSTI)

We propose a model for a continuously pumped single-pass amplifier for continuous and pulsed laser beams. The model takes into account Gaussian shape and focusing geometry of pump and seed beam. As the full-wave simulation is complex we have developed a largely simplified numerical method that can be applied to rotationally symmetric geometries. With the tapered-shell model we treat (focused) propagation and amplification of an initially Gaussian beam in a gain crystal. The implementation can be done with a few lines of code that are given in this paper. With this code, a numerical parameter optimization is straightforward and example results are shown. We compare the results of our simple model with those of a full-wave simulation and show that they agree well. A comparison of model and experimental data also shows good agreement. We investigate in detail different regimes of amplification, namely the unsaturated, the fully saturated, and the intermediate regime. Because the amplification process is affected by spatially varying saturation and exhibits a nonlinear response against pump and seed power, no analytical expression for the expected output is available. For modeling of the amplification we employ a four-level system and show that if the fluorescence lifetime of the gain medium is larger than the inverse repetition rate of the seed beam, continuous-wave amplification can be employed to describe the amplification process of ultrashort pulse trains. We limit ourselves to this regime, which implies that if titanium:sapphire is chosen as gain medium the laser repetition rate has to be larger than a few megahertz. We show detailed simulation results for titanium:sapphire for a large parameter set.

Ozawa, Akira; Udem, Thomas; Zeitner, Uwe D.; Haensch, Theodor W.; Hommelhoff, Peter [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Fraunhofer-Institut fuer Angewandte Optik und Feinmechanik IOF, Albert-Einstein-Strasse 7, D-07745 Jena (Germany); Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany)

2010-09-15T23:59:59.000Z

487

Water Transport in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization  

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

in PEM Fuel Cells: in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization J. Vernon Cole and Ashok Gidwani CFDRC Prepared for: DOE Hydrogen Fuel Cell Kickoff Meeting February 13, 2007 This presentation does not contain any proprietary or confidential information. Background Water Management Issues Arise From: ƒ Generation of water by cathodic reaction ƒ Membrane humidification requirements ƒ Capillary pressure driven transport through porous MEA and GDL materials ƒ Scaling bipolar plate channel dimensions J.H. Nam and M. Kaviany, Int. J. Heat Mass Transfer, 46, pp. 4595-4611 (2003) Relevant Barriers and Targets ƒ Improved Gas Diffusion Layer, Flow Fields, Membrane Electrode Assemblies Needed to Improve Water Management: * Flooding blocks reactant transport

488

L3 Milestone Use Computational Model to Design and Optimize Welding Conditions to Suppress Helium  

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

L3 Milestone L3 Milestone Use Computational Model to Design and Optimize Welding Conditions to Suppress Helium Cracking during Welding June 2012 Wei Zhang and Zhili Feng, ORNL Eric Willis, EPRI Background and Objectives Today, welding is widely used for repair, maintenance and upgrade of nuclear reactor components. As a critical technology to extend the service life of nuclear power plants beyond 60 years, weld technology must be further developed to meet new challenges associated with the aging of the plants, such as control and mitigation of the detrimental effects of weld residual stresses and repair of highly irradiated materials. To meet this goal, fundamental understanding of the "welding" effect is necessary for development of new and improved welding technologies.

489

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

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

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

490

Online Robot Dead Reckoning Localization Using Maximum Relative Entropy Optimization With Model Constraints  

SciTech Connect (OSTI)

The principle of Maximum relative Entropy optimization was analyzed for dead reckoning localization of a rigid body when observation data of two attached accelerometers was collected. Model constraints were derived from the relationships between the sensors. The experiment's results confirmed that accelerometers each axis' noise can be successfully filtered utilizing dependency between channels and the dependency between time series data. Dependency between channels was used for a priori calculation, and a posteriori distribution was derived utilizing dependency between time series data. There was revisited data of autocalibration experiment by removing the initial assumption that instantaneous rotation axis of a rigid body was known. Performance results confirmed that such an approach could be used for online dead reckoning localization.

Urniezius, Renaldas [Kaunas University of Technology, Kaunas (Lithuania)

2011-03-14T23:59:59.000Z

491

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

492

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

493

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

494

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

495

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.

496

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

497

Optimizing future imaging survey of galaxies to confront dark energy and modified gravity models  

Science Journals Connector (OSTI)

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as models of modified gravity, yet predict different growth of structure histories. We parametrize the cosmic expansion by the two parameters, w0 and wa, and the linear growth rate of density fluctuations by Linder’s ?, independently. Dark energy models generically predict ??0.55, while the Dvali-Gabadadze-Porrati (DGP) model ??0.68. To determine if future imaging surveys can constrain ? within 20% (or ??survey such as the ongoing Hyper Suprime-Cam (HSC) project. Under the condition that the total observation time is fixed, we compute the figure of merit (FoM) as a function of the exposure time texp. We find that the tomography technique effectively improves the FoM, which has a broad peak around texp?several?10??min; a shallow and wide survey is preferred to constrain the ? parameter. While ??survey alone, one can improve the constraints by combining with a follow-up spectroscopic survey like Wide-field Fiber-fed Multi-Object Spectrograph (WFMOS) and/or future cosmic microwave background (CMB) observations.

Kazuhiro Yamamoto; David Parkinson; Takashi Hamana; Robert C. Nichol; Yasushi Suto

2007-07-09T23:59:59.000Z

498

Optimizing future imaging survey of galaxies to confront dark energy and modified gravity models  

E-Print Network [OSTI]

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as models of modified gravity, yet predict different growth of structure histories. We parameterize the cosmic expansion by the two parameters, $w_0$ and $w_a$, and the linear growth rate of density fluctuations by Linder's $\\gamma$, independently. Dark energy models generically predict $\\gamma \\approx 0.55$, while the DGP model $\\gamma \\approx 0.68$. To determine if future imaging surveys can constrain $\\gamma$ within 20 percent (or $\\Delta\\gammasurvey such as the on-going Hyper Suprime-Cam (HSC) project. Under the condition that the total observation time is fixed, we compute the Figure of Merit (FoM) as a function of the exposure time $\\texp$. We find that the tomography technique effectively improves the FoM, which has a broad peak around $\\texp\\simeq {\\rm several}\\sim 10$ minutes; a shallow and wide survey is preferred to constrain the $\\gamma$ parameter. While $\\Delta\\gamma survey alone, one can improve the constraints by combining with a follow-up spectroscopic survey like WFMOS and/or future CMB observations.

Kazuhiro Yamamoto; David Parkinson; Takashi Hamana; Robert C. Nichol; Yasushi Suto

2007-04-23T23:59:59.000Z

499

Improved treatment of uncertainty in hydrologic modeling: Combining the strengths of global optimization and data  

E-Print Network [OSTI]

optimization and data assimilation Jasper A. Vrugt,1 Cees G. H. Diks,2 Hoshin V. Gupta,3 Willem Bouten,1

Vrugt, Jasper A.

500

Modeling Bacterial Population Growth from Stochastic Single-Cell Dynamics  

Science Journals Connector (OSTI)

...from the Matlab optimization...problem (equation 7), leading...and 32C. Simulation of bacterial...division. The process is then repeated...2004. Simulation of distributed...systems using a Matlab-based method...numerical simulation of stochastic differential equations. SIAM Rev...Appendix. PDF, 45K Supplemental...

Antonio A. Alonso; Ignacio Molina; Constantinos Theodoropoulos

2014-06-13T23:59:59.000Z