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1

Regional Dynamics Model (REDYN) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to: navigation, searchVirginia Blue Ridge And Piedmont Provinces | Open EnergyDynamics Model

2

Queuing models System dynamics models  

E-Print Network [OSTI]

models Value chain models Business Model / Organizational Perspective Process Perspective Information#12;#12;#12;#12;Queuing models System dynamics models #12;#12;#12;#12;Blueprint or touchpoint

Glushko, Robert J.

3

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

4

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

5

Modal aerosol dynamics modeling  

SciTech Connect (OSTI)

The report presents the governing equations for representing aerosol dynamics, based on several different representations of the aerosol size distribution. Analytical and numerical solution techniques for these governing equations are also reviewed. Described in detail is a computationally efficient numerical technique for simulating aerosol behavior in systems undergoing simultaneous heat transfer, fluid flow, and mass transfer in and between the gas and condensed phases. The technique belongs to a general class of models known as modal aerosol dynamics (MAD) models. These models solve for the temporal and spatial evolution of the particle size distribution function. Computational efficiency is achieved by representing the complete aerosol population as a sum of additive overlapping populations (modes), and solving for the time rate of change of integral moments of each mode. Applications of MAD models for simulating aerosol dynamics in continuous stirred tank aerosol reactors and flow aerosol reactors are provided. For the application to flow aerosol reactors, the discussion is developed in terms of considerations for merging a MAD model with the SIMPLER routine described by Patankar (1980). Considerations for incorporating a MAD model into the U.S. Environmental Protection Agency's Regional Particulate Model are also described. Numerical and analytical techniques for evaluating the size-space integrals of the modal dynamics equations (MDEs) are described. For multimodal logonormal distributions, an analytical expression for the coagulation integrals of the MDEs, applicable for all size regimes, is derived, and is within 20% of accurate numerical evaluation of the same moment coagulation integrals. A computationally efficient integration technique, based on Gauss-Hermite numerical integration, is also derived.

Whitby, E.R.; McMurry, P.H.; Shankar, U.; Binkowski, F.S.

1991-02-01T23:59:59.000Z

6

Tools for dynamic model development  

E-Print Network [OSTI]

For this thesis, several tools for dynamic model development were developed and analyzed. Dynamic models can be used to simulate and optimize the behavior of a great number of natural and engineered systems, from the ...

Schaber, Spencer Daniel

2014-01-01T23:59:59.000Z

7

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

8

A Relativistic Dynamical Collapse Model  

E-Print Network [OSTI]

A model is discussed where all operators are constructed from a quantum scalar field whose energy spectrum takes on all real values. The Schr\\"odinger picture wave function depends upon space and time coordinates for each particle, as well as an inexorably increasing evolution parameter $s$ which labels a foliation of space-like hypersurfaces. The model is constructed to be manifestly Lorentz invariant in the interaction picture. Free particle states and interactions are discussed in this framework. Then, the formalism of the CSL (Continuous Spontaneous Localization) theory of dynamical collapse is applied. The collapse-generating operator is chosen to to be the particle number space-time density. Unlike previous relativistically invariant models, the vacuum state is not excited. The collapse dynamics depends upon two parameters, a parameter $\\Lambda$ which represents the collapse rate/volume and a scale factor $\\ell$. A common example of collapse dynamics, involving a clump of matter in a superposition of two locations, is analyzed. The collapse rate is shown to be identical to that of non-relativistic CSL when the GRW-CSL choice of $\\ell=a=10^{-5}$cm, is made, along with $\\Lambda=\\lambda/a^{3}$ (GRW-CSL choice $\\lambda=10^{-16}s^{-1}$). However, it is also shown that the change of mass of a nucleon over the age of the universe is then unacceptably large. The case where $\\ell$ is the size of the universe is then considered. It is shown that the collapse behavior is satisfactory and the change of mass over the age of the universe is acceptably small, when $\\Lambda= \\lambda/\\ell a^{2}$.

Philip Pearle

2014-12-21T23:59:59.000Z

9

Quantitative Modeling of High Temperature Magnetization Dynamics  

SciTech Connect (OSTI)

Final Technical Report Project title: Quantitative Modeling of High Temperature Magnetization Dynamics DOE/Office of Science Program Manager Contact: Dr. James Davenport

Zhang, Shufeng

2009-03-01T23:59:59.000Z

10

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

11

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

12

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

13

Benchmarking of Planning Models Using Recorded Dynamics  

SciTech Connect (OSTI)

Power system planning extensively uses model simulation to understand the dynamic behaviors and determine the operating limits of a power system. Model quality is key to the safety and reliability of electricity delivery. Planning model benchmarking, or 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 dynamic behavior of power system components, it has been essential to validate models against actual measurements. The development of phasor technology provides such measurements and represents a new opportunity for model validation as phasor measurements can capture power system dynamics with high-speed, time-synchronized data. Previously, methods for rigorous comparison of model simulation and recorded dynamics have been developed and applied to quantify model quality of power plants in the Western Electricity Coordinating Council (WECC). These methods can locate model components which need improvement. Recent work continues this effort and focuses on how model parameters may be calibrated to match recorded dynamics after the problematic model components are identified. A calibration method using Extended Kalman Filter technique is being developed. This paper provides an overview of prior work on model validation and presents new development on the calibration method and initial results of model parameter calibration.

Huang, Zhenyu; Yang, Bo; Kosterev, Dmitry

2009-03-15T23:59:59.000Z

14

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

15

Dynamics Modelling of Biolistic Gene Guns  

SciTech Connect (OSTI)

The gene transfer process using biolistic gene guns is a highly dynamic process. To achieve good performance, the process needs to be well understood and controlled. Unfortunately, no dynamic model is available in the open literature for analysing and controlling the process. This paper proposes such a model. Relationships of the penetration depth with the helium pressure, the penetration depth with the acceleration distance, and the penetration depth with the micro-carrier radius are presented. Simulations have also been conducted. The results agree well with experimental results in the open literature. The contribution of this paper includes a dynamic model for improving and manipulating performance of the biolistic gene gun.

Zhang, M.; Tao, W.; Pianetta, P.A.

2009-06-04T23:59:59.000Z

16

DYNAMIC MODELING PROTON EXCHANGE MEMBRANE FUEL CELL  

E-Print Network [OSTI]

DYNAMIC MODELING PROTON EXCHANGE MEMBRANE FUEL CELL OVERVIEW Current/Completed Plug Power reformer from GE · Use of GenCore to investigate effects of fuel quality and dynamic changes in fuel to garner SCAQMD funding for fuel cell testing GenCore system is sensitive to diluents · As built design

Mease, Kenneth D.

17

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

18

Modeling Dynamics of Post Disaster Recovery  

E-Print Network [OSTI]

Subject: Civil Engineering iii ABSTRACT Modeling Dynamics of Post Disaster Recovery. (August 2011) Ali Nejat, B.S., Zanjan University, Zanjan, Iran; M.S., Islamic Azad University, Tehran, Iran Chair of Advisory Committee: Dr. Ivan Damnjanovic... MODELING DYNAMICS OF POST DISASTER RECOVERY A Dissertation by ALI NEJAT 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...

Nejat, Ali

2012-10-19T23:59:59.000Z

19

Protein viscoelastic dynamics: a model system  

E-Print Network [OSTI]

A model system inspired by recent experiments on the dynamics of a folded protein under the influence of a sinusoidal force is investigated and found to replicate many of the response characteristics of such a system. The essence of the model is a strongly over-damped oscillator described by a harmonic restoring force for small displacements that reversibly yields to stress under sufficiently large displacement. This simple dynamical system also reveals unexpectedly rich behavior, exhibiting a series of dynamical transitions and analogies with equilibrium thermodynamic phase transitions. The effects of noise and of inertia are briefly considered and described.

Craig Fogle; Joseph Rudnick; David Jasnow

2015-02-02T23:59:59.000Z

20

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

Consistent nonlinear dynamics: identifying model inadequacy  

E-Print Network [OSTI]

Empirical modelling often aims for the simplest model consistent with the data. A new technique is presented which quantifies the consistency of the model dynamics as a function of location in state space. As is well-known, traditional statistics of nonlinear models like root-mean-square (RMS) forecast error can prove misleading. Testing consistency is shown to overcome some of the deficiencies of RMS error, both within the perfect model scenario and when applied to data from several physical systems using previously published models. In particular, testing for consistent nonlinear dynamics provides insight towards (i) identifying when a delay reconstruction fails to be an embedding, (ii) allowing state dependent model selection and (iii) optimising local neighbourhood size. It also provides a more relevant (state dependent) threshold for identifying false nearest neighbours.

Patrick E. McSharry; Leonard A. Smith

2004-03-09T23:59:59.000Z

22

Human Muscle Fatigue Model in Dynamic Motions  

E-Print Network [OSTI]

Human Muscle Fatigue Model in Dynamic Motions Ruina Ma, Damien Chablat, Fouad Bennis, and Liang Ma Abstract Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main

Boyer, Edmond

23

Modeling dynamic swarms q Bernard Ghanem a,  

E-Print Network [OSTI]

a c t This paper proposes the problem of modeling video sequences of dynamic swarms (DSs). We define of our method by conducting experiments on real and synthetic video sequences. Real sequences of birds Elsevier Inc. All rights reserved. 1. Introduction This paper is about modeling video sequences of a dense

Ahuja, Narendra

24

Modeling the Dynamics of Compromised Networks  

SciTech Connect (OSTI)

Accurate predictive models of compromised networks would contribute greatly to improving the effectiveness and efficiency of the detection and control of network attacks. Compartmental epidemiological models have been applied to modeling attack vectors such as viruses and worms. We extend the application of these models to capture a wider class of dynamics applicable to cyber security. By making basic assumptions regarding network topology we use multi-group epidemiological models and reaction rate kinetics to model the stochastic evolution of a compromised network. The Gillespie Algorithm is used to run simulations under a worst case scenario in which the intruder follows the basic connection rates of network traffic as a method of obfuscation.

Soper, B; Merl, D M

2011-09-12T23:59:59.000Z

25

Dynamical System Analysis for a phantom model  

E-Print Network [OSTI]

The paper deals with a dynamical system analysis related to phantom cosmological model . Here gravity is coupled to phantom scalar field having scalar coupling function and a potential. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables and assuming some suitable form of the potential function. Finally, critical points are evaluated, their nature have been analyzed and corresponding cosmological scenario has been discussed.

Nilanjana Mahata; Subenoy Chakraborty

2014-04-24T23:59:59.000Z

26

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

27

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

28

Modeling the Dynamics of Fermentation and Respiratory  

E-Print Network [OSTI]

, denitrification, and SO4-reduction). The accumulation of acetate as a fermentation product within the plume species, e.g., H2(aq) or acetate, followed by respiration by other groups of organisms where fermentationModeling the Dynamics of Fermentation and Respiratory Processes in a Groundwater Plume of Phenolic

Sheffield, University of

29

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

30

Feature extraction for structural dynamics model validation  

SciTech Connect (OSTI)

This study focuses on defining and comparing response features that can be used for structural dynamics model validation studies. Features extracted from dynamic responses obtained analytically or experimentally, such as basic signal statistics, frequency spectra, and estimated time-series models, can be used to compare characteristics of structural system dynamics. By comparing those response features extracted from experimental data and numerical outputs, validation and uncertainty quantification of numerical model containing uncertain parameters can be realized. In this study, the applicability of some response features to model validation is first discussed using measured data from a simple test-bed structure and the associated numerical simulations of these experiments. issues that must be considered were sensitivity, dimensionality, type of response, and presence or absence of measurement noise in the response. Furthermore, we illustrate a comparison method of multivariate feature vectors for statistical model validation. Results show that the outlier detection technique using the Mahalanobis distance metric can be used as an effective and quantifiable technique for selecting appropriate model parameters. However, in this process, one must not only consider the sensitivity of the features being used, but also correlation of the parameters being compared.

Hemez, Francois [Los Alamos National Laboratory; Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Nishio, Mayuko [UNIV OF TOKYO; Worden, Keith [UNIV OF SHEFFIELD; Takeda, Nobuo [UNIV OF TOKYO

2010-11-08T23:59:59.000Z

31

Structural system identification: Structural dynamics model validation  

SciTech Connect (OSTI)

Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

Red-Horse, J.R.

1997-04-01T23:59:59.000Z

32

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

33

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

34

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

35

Dynamical Models for the Milky Way  

E-Print Network [OSTI]

The only way to map the Galaxy's gravitational potential $\\Phi({\\bf x})$ and the distribution of matter that produces it is by modelling the dynamics of stars and gas. Observations of the kinematics of gas provide key information about gradients of $\\Phi$ within the plane, but little information about the structure of $\\Phi$ out of the plane. Traditional Galaxy models {\\em assume}, for each of the Galaxy's components, arbitrary flattenings, which together with the components' relative masses yield the model's equipotentials. However, the Galaxy's isopotential surfaces should be {\\em determined\\/} directly from the motions of stars that move far from the plane. Moreover, from the kinematics of samples of such stars that have well defined selection criteria, one should be able not only to map $\\Phi$ at all positions, but to determine the distribution function $f_i({\\bf x},{\\bf v})$ of each stellar population $i$ studied. These distribution functions will contain a wealth of information relevant to the formation and evolution of the Galaxy. An approach to fitting a wide class of dynamical models to the very heterogeneous body of available data is described and illustrated.

Walter Dehnen; James Binney

1996-01-10T23:59:59.000Z

36

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"

37

Gradient Navigation Model for Pedestrian Dynamics  

E-Print Network [OSTI]

We present a new microscopic ODE-based model for pedestrian dynamics: the Gradient Navigation Model. The model uses a superposition of gradients of distance functions to directly change the direction of the velocity vector. The velocity is then integrated to obtain the location. The approach differs fundamentally from force based models needing only three equations to derive the ODE system, as opposed to four in, e.g., the Social Force Model. Also, as a result, pedestrians are no longer subject to inertia. Several other advantages ensue: Model induced oscillations are avoided completely since no actual forces are present. The derivatives in the equations of motion are smooth and therefore allow the use of fast and accurate high order numerical integrators. At the same time, existence and uniqueness of the solution to the ODE system follow almost directly from the smoothness properties. In addition, we introduce a method to calibrate parameters by theoretical arguments based on empirically validated assumptions rather than by numerical tests. These parameters, combined with the accurate integration, yield simulation results with no collisions of pedestrians. Several empirically observed system phenomena emerge without the need to recalibrate the parameter set for each scenario: obstacle avoidance, lane formation, stop-and-go waves and congestion at bottlenecks. The density evolution in the latter is shown to be quantitatively close to controlled experiments. Likewise, we observe a dependence of the crowd velocity on the local density that compares well with benchmark fundamental diagrams.

Felix Dietrich; Gerta Köster

2014-05-14T23:59:59.000Z

38

ONGOING RESEARCH PROJECTS Model of tropical forest structure and dynamics  

E-Print Network [OSTI]

ONGOING RESEARCH PROJECTS Model of tropical forest structure and dynamics There is a need canopy structure and partitions dynamic rates for a tropical forest on Barro Colorado Island (BCI structure and partitions dynamic rates in a tropical forest. In Review. Journal of Ecology. #12;PPA model

Hill, Jeffrey E.

39

Unbounded dynamics in dissipative flows: Rössler model  

SciTech Connect (OSTI)

Transient chaos and unbounded dynamics are two outstanding phenomena that dominate in chaotic systems with large regions of positive and negative divergences. Here, we investigate the mechanism that leads the unbounded dynamics to be the dominant behavior in a dissipative flow. We describe in detail the particular case of boundary crisis related to the generation of unbounded dynamics. The mechanism of the creation of this crisis in flows is related to the existence of an unstable focus-node (or a saddle-focus) equilibrium point and the crossing of a chaotic invariant set of the system with the weak-(un)stable manifold of the equilibrium point. This behavior is illustrated in the well-known Rössler model. The numerical analysis of the system combines different techniques as chaos indicators, the numerical computation of the bounded regions, and bifurcation analysis. For large values of the parameters, the system is studied by means of Fenichel's theory, providing formulas for computing the slow manifold which influences the evolution of the first stages of the orbit.

Barrio, Roberto, E-mail: rbarrio@unizar.es; Serrano, Sergio, E-mail: sserrano@unizar.es [Computational Dynamics Group, Dpto. Matemática Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)] [Computational Dynamics Group, Dpto. Matemática Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Blesa, Fernando, E-mail: fblesa@unizar.es [Computational Dynamics Group, Dpto. Física Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)] [Computational Dynamics Group, Dpto. Física Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)

2014-06-15T23:59:59.000Z

40

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

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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

Dynamics of an Economics Model for Generation Coupled to the OPA Power Transmission Model  

E-Print Network [OSTI]

Dynamics of an Economics Model for Generation Coupled to the OPA Power Transmission Model B. A a dynamic model of the power transmission system (OPA) and a simple economic model of power generation development. Despite the simplicity of this economic model, complex dynamics both in the economics (prices

Dobson, Ian

42

A lattice mesoscopic model of dynamically heterogeneous fluids  

E-Print Network [OSTI]

We introduce a mesoscopic three-dimensional Lattice Boltzmann Model which attempts to mimick the physical features associated with cage effects in dynamically heterogeneous fluids. To this purpose, we extend the standard Lattice Boltzmann dynamics with self-consistent constraints based on the non-local density of the surrounding fluid. The resulting dynamics exhibits typical features of dynamic heterogeneous fluids, such as non-Gaussian density distributions and long-time relaxation. Due to its intrinsically parallel dynamics, and absence of statistical noise, the method is expected to compute significantly faster than molecular dynamics, Monte Carlo and lattice glass models.

A. Lamura; S. Succi

2005-10-04T23:59:59.000Z

43

Solid Oxide Fuel Cell: Perspective of Dynamic Modeling and Control  

E-Print Network [OSTI]

Solid Oxide Fuel Cell: Perspective of Dynamic Modeling and Control Biao Huang Yutong Qi Monjur: This paper presents a review of state-of-the-art solid oxide fuel cells (SOFC), from perspective of dynamic. Keywords: Solid Oxide Fuel Cell, Control Relevant Model, Model Predictive Control 1. INTRODUCTION Today

Huang, Biao

44

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

45

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

46

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

47

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

48

Stochastic modeling of lift and drag dynamics under turbulent conditions  

E-Print Network [OSTI]

measurement. The model is being developed with the aim to integrate it into a general wind energy converter dynamics, drag dynamics. 1 Introduction Wind energy converters (WECs) are permanently exposed to turbulent.peinke@forwind.de in every second, which imposes different risks. The dynamical nature of the wind has a significant impact

Peinke, Joachim

49

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

50

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

51

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

52

A Qualitative Simulation Approach for Fuzzy Dynamical Models  

E-Print Network [OSTI]

.g., a nuclear power plant in unexpected emergency situations) or because if does not yet exist (eA Qualitative Simulation Approach for Fuzzy Dynamical Models ANDREA BONARINI and GIANLUCA BONTEMPI Politecnico di Milano This article deal with simulation of approximate models of dynamic systems. We propose

Bontempi, Gianluca

53

Direct modelling of envelope dynamics in resonant inverters  

E-Print Network [OSTI]

Direct modelling of envelope dynamics in resonant inverters Y. Yin, R. Zane, R. Erickson and J. Glaser A direct dynamic modelling approach is proposed for envelope signals in resonant inverters tank and simplify analysis and controller design. Introduction: High-frequency DC-AC inverters

54

Static and Dynamic Debugging of Modelica Models Adrian Pop1  

E-Print Network [OSTI]

Static and Dynamic Debugging of Modelica Models Adrian Pop1 , Martin Sjölund1 , Adeel Asghar1@elet.polimi.it Abstract The high abstraction level of equation-based object- oriented languages (EOO) such as Modelica has and dynamic debugging methods for Modelica models and a debugger prototype that addresses several of those

Zhao, Yuxiao

55

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.

56

Generic solar photovoltaic system dynamic simulation model specification.  

SciTech Connect (OSTI)

This document is intended to serve as a specification for generic solar photovoltaic (PV) system positive-sequence dynamic models to be implemented by software developers and approved by the WECC MVWG for use in bulk system dynamic simulations in accordance with NERC MOD standards. Two specific dynamic models are included in the scope of this document. The first, a Central Station PV System model, is intended to capture the most important dynamic characteristics of large scale (> 10 MW) PV systems with a central Point of Interconnection (POI) at the transmission level. The second, a Distributed PV System model, is intended to represent an aggregation of smaller, distribution-connected systems that comprise a portion of a composite load that might be modeled at a transmission load bus.

Ellis, Abraham; Behnke, Michael Robert; Elliott, Ryan Thomas

2013-10-01T23:59:59.000Z

57

FORMAL SEMANTICS AND VERIFICATION OF DYNAMIC RELIABILITY BLOCK DIAGRAMS FOR SYSTEM RELIABILITY MODELING  

E-Print Network [OSTI]

FORMAL SEMANTICS AND VERIFICATION OF DYNAMIC RELIABILITY BLOCK DIAGRAMS FOR SYSTEM RELIABILITY captured by existing reliability modeling tools. In this paper, we introduce a new reliability modeling tool, called dynamic reliability block diagrams (DRBD), for modeling dynamic relationships between

Xu, Haiping

58

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

59

Dynamic wind turbine models in power system simulation tool  

E-Print Network [OSTI]

Dynamic wind turbine models in power system simulation tool DIgSILENT Anca D. Hansen, Florin Iov Iov, Poul Sørensen, Nicolaos Cutululis, Clemens Jauch, Frede Blaabjerg Title: Dynamic wind turbine system simulation tool PowerFactory DIgSILENT for different wind turbine concepts. It is the second

60

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

REGULAR ARTICLE A Simple Dynamic Model of Respiratory Pump  

E-Print Network [OSTI]

). Mathematical models are used to understand these interactions and the mechanics of respiratory system better) and introduce some dynamic properties of the respiratory system. The passive elements (rib cage and abdomen not take into account the dynamic component of the system, it appears valid for different respiratory

Fontecave-Jallon, Julie

62

Modeling and Management of Nonlinear Dependencies Copulas in Dynamic Financial  

E-Print Network [OSTI]

an important tool for decision making and an essential part of enterprise risk management (ERM), particularly. Keywords: Non-Life Insurance, Risk Management, Dynamic Financial Analysis, Co- pulas, PerformanceModeling and Management of Nonlinear Dependencies ­ Copulas in Dynamic Financial Analysis Martin

Ulm, Universität

63

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

64

Symbolic Dynamics in a Matching Labour Market Model  

E-Print Network [OSTI]

In this paper we apply the techniques of symbolic dynamics to the analysis of a labor market which shows large volatility in employment flows. In a recent paper, Bhattacharya and Bunzel \\cite{BB} have found that the discrete time version of the Pissarides-Mortensen matching model can easily lead to chaotic dynamics under standard sets of parameter values. To conclude about the existence of chaotic dynamics in the numerical examples presented in the paper, the Li-Yorke theorem or the Mitra sufficient condition were applied which seems questionable because they may lead to misleading conclusions. Moreover, in a more recent version of the paper, Bhattacharya and Bunzel \\cite{BB1} present new results in which chaos is completely removed from the dynamics of the model. Our paper explores the matching model so interestingly developed by the authors with the following objectives in mind: (i) to show that chaotic dynamics may still be present in the model for standard parameter values; (ii) to clarify some open questions raised by the authors in \\cite{BB}, by providing a rigorous proof of the existence of chaotic dynamics in the model through the computation of topological entropy in a symbolic dynamics setting.

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

2006-08-01T23:59:59.000Z

65

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

66

Human Growth and Body Weight Dynamics: An Integrative Systems Model  

E-Print Network [OSTI]

Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and ...

Rahmandad, Hazhir

67

Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion  

E-Print Network [OSTI]

. Lozano June 2010 SSL # 6-10 #12;#12;Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion Nanako Takahashi, Paulo C. Lozano June 2010 SSL # 6-10 This work is based on the unaltered text

68

2.003 Modeling Dynamics and Control I, Spring 2002  

E-Print Network [OSTI]

First of two-term sequence on modeling, analysis and control of dynamic systems. Mechanical translation, uniaxial rotation, electrical circuits and their coupling via levers, gears and electro-mechanical devices. Analytical ...

Trumper, David L.

69

Modeling and control of undesirable dynamics in atomic force microscopes  

E-Print Network [OSTI]

The phenomenal resolution and versatility of the atomic force microscope (AFM), has made it a widely-used instrument in nanotechnology. In this thesis, a detailed model of AFM dynamics has been developed. It includes a new ...

El Rifai, Osamah M

2002-01-01T23:59:59.000Z

70

Models of dynamic RNA regulation in mammalian cells  

E-Print Network [OSTI]

Complex molecular circuits, consisting of multiple intertwined feedback loops and non-linear interactions, are a hallmark of every living cell, and a model of a dynamic complex network. Here, I systematically study the ...

Rabani, Michal

2013-01-01T23:59:59.000Z

71

Modeling exchange rate dependence dynamics at different time horizons  

E-Print Network [OSTI]

, Copula-GARCH, Conditional dependence, Dynamic copula Corresponding author. Tel.: +44(0) 247 657 4297. Financial time-series are often modeled with GARCH type models. In the multivariate GARCH literature there exist several models, like CCC- GARCH, DVEC, matrix-diagonal GARCH, BEKK and principal components GARCH

Embrechts, Paul

72

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

73

RESEARCH ARTICLE Modelling multi-species response to landscape dynamics  

E-Print Network [OSTI]

and to the spatio-temporal configuration of urban brownfield habitats in a multi-species approach (37 plant and 43- sion time of brownfield habitats required to support all and especially regionally rare species Dynamic landscape Á Species distribution model Á Habitat model Á Urban brownfields Á Model averaging Á

Kleyer, Michael

74

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

75

Dynamic reactor modeling with applications to SPR and ZEDNA.  

SciTech Connect (OSTI)

A dynamic reactor model has been developed for pulse-type reactor applications. The model predicts reactor power, axial and radial fuel expansion, prompt and delayed neutron population, and prompt and delayed gamma population. All model predictions are made as a function of time. The model includes the reactivity effect of fuel expansion on a dynamic timescale as a feedback mechanism for reactor power. All inputs to the model are calculated from first principles, either directly by solving systems of equations, or indirectly from Monte Carlo N-Particle Transport Code (MCNP) derived results. The model does not include any empirical parameters that can be adjusted to match experimental data. Comparisons of model predictions to actual Sandia Pulse Reactor SPR-III pulses show very good agreement for a full range of pulse magnitudes. The model is also applied to Z-pinch externally driven neutron assembly (ZEDNA) type reactor designs to model both normal and off-normal ZEDNA operations.

Suo-Anttila, Ahti Jorma

2011-12-01T23:59:59.000Z

76

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

77

A stochastic evolutionary model for capturing human dynamics  

E-Print Network [OSTI]

The recent interest in human dynamics has led researchers to investigate the stochastic processes that explain human behaviour in various contexts. Here we propose a generative model to capture the dynamics of survival analysis, traditionally employed in clinical trials and reliability analysis in engineering. We derive a general solution for the model in the form of a product, and then a continuous approximation to the solution via the renewal equation describing age-structured population dynamics. This enables us to model a wide rage of survival distributions, according to the choice of the mortality distribution. We provide empirical evidence for the validity of the model from a longitudinal data set of popular search engine queries over 114 months, showing that the survival function of these queries is closely matched by the solution for our model with power-law mortality.

Fenner, Trevor; Loizou, George

2015-01-01T23:59:59.000Z

78

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

79

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

80

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

A Dynamic Model coupling Photoacclimation and Photoinhibition in Microalgae  

E-Print Network [OSTI]

A Dynamic Model coupling Photoacclimation and Photoinhibition in Microalgae Philipp Hartmann1, Andreas Nikolaou2, Beno^it Chachuat2, Olivier Bernard1 Abstract-- Microalgae are often considered in microalgae, thereby spanning multiple time scales. The properties of the model are investigated under quasi

Boyer, Edmond

82

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

83

Passive dynamic walking with knees : a point foot model  

E-Print Network [OSTI]

In this thesis, a hybrid model for a passive 2D walker with knees and point feet is presented. The step cycle of the model has two phases of continuous dynamics: one with an unlocked knee configuration and a second one ...

Hsu Chen, Vanessa F. (Vanessa Fang)

2007-01-01T23:59:59.000Z

84

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

85

Long-wave models of thin film fluid dynamics  

E-Print Network [OSTI]

Centre manifold techniques are used to derive rationally a description of the dynamics of thin films of fluid. The derived model is based on the free-surface $\\eta(x,t)$ and the vertically averaged horizontal velocity $\\avu(x,t)$. The approach appears to converge well and has significant differences from conventional depth-averaged models.

A. J. Roberts

1994-11-04T23:59:59.000Z

86

Modeling Lake Erie ice dynamics: Process studies , Haoguo Hu2  

E-Print Network [OSTI]

Modeling Lake Erie ice dynamics: Process studies Jia Wang1 , Haoguo Hu2 , and Xuezhi Bai2 1 NOAA of Michigan 4840 S. State Road, Ann Arbor, MI 48108 Abstract. A Great Lakes Ice-circulation Model (GLIM derived from meteorological measurements. After the seasonal cycles of ice concentration, thickness

87

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

88

Variational Inference in Stochastic Dynamic Environmental Models Dan Cornford1  

E-Print Network [OSTI]

Variational Inference in Stochastic Dynamic Environmental Models Dan Cornford1 , Manfred Opper2 number of degrees of freedom. Environmental forecasting centres have taken strategic decisions to develop on related phenomena, such as flooding and storm damage, and on the spread of pollutants. The models needed

Roulstone, Ian

89

Modeling and simulation of consumer response to dynamic pricing.  

SciTech Connect (OSTI)

Assessing the impacts of dynamic-pricing under the smart grid concept is becoming extremely important for deciding its full deployment. In this paper, we develop a model that represents the response of consumers to dynamic pricing. In the model, consumers use forecasted day-ahead prices to shift daily energy consumption from hours when the price is expected to be high to hours when the price is expected to be low while maintaining the total energy consumption as unchanged. We integrate the consumer response model into the Electricity Market Complex Adaptive System (EMCAS). EMCAS is an agent-based model that simulates restructured electricity markets. We explore the impacts of dynamic-pricing on price spikes, peak demand, consumer energy bills, power supplier profits, and congestion costs. A simulation of an 11-node test network that includes eight generation companies and five aggregated consumers is performed for a period of 1 month. In addition, we simulate the Korean power system.

Valenzuela, J.; Thimmapuram, P.; Kim, J (Decision and Information Sciences); (Auburn Univ.)

2012-08-01T23:59:59.000Z

90

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

91

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

92

Wind turbine control systems: Dynamic model development using system identification and the fast structural dynamics code  

SciTech Connect (OSTI)

Mitigating the effects of damaging wind turbine loads and responses extends the lifetime of the turbine and, consequently, reduces the associated Cost of Energy (COE). Active control of aerodynamic devices is one option for achieving wind turbine load mitigation. Generally speaking, control system design and analysis requires a reasonable dynamic model of {open_quotes}plant,{close_quotes} (i.e., the system being controlled). This paper extends the wind turbine aileron control research, previously conducted at the National Wind Technology Center (NWTC), by presenting a more detailed development of the wind turbine dynamic model. In prior research, active aileron control designs were implemented in an existing wind turbine structural dynamics code, FAST (Fatigue, Aerodynamics, Structures, and Turbulence). In this paper, the FAST code is used, in conjunction with system identification, to generate a wind turbine dynamic model for use in active aileron control system design. The FAST code is described and an overview of the system identification technique is presented. An aileron control case study is used to demonstrate this modeling technique. The results of the case study are then used to propose ideas for generalizing this technique for creating dynamic models for other wind turbine control applications.

Stuart, J.G.; Wright, A.D.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

93

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

94

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

95

A Markov model of land use dynamics  

E-Print Network [OSTI]

The application of the Markov chain to modeling agricultural succession is well known. In most cases, the main problem is the inference of the model, i.e. the estimation of the transition matrix. In this work we present methods to estimate the transition matrix from historical observations. In addition to the estimator of maximum likelihood (MLE), we also consider the Bayes estimator associated with the Jeffreys prior. This Bayes estimator will be approximated by a Markov chain Monte Carlo (MCMC) method. We also propose a method based on the sojourn time to test the adequation of Markov chain model to the dataset.

Campillo, Fabien; Raherinirina, Angelo; Rakotozafy, Rivo

2011-01-01T23:59:59.000Z

96

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

97

A dynamic model of industrial energy demand in Kenya  

SciTech Connect (OSTI)

This paper analyses the effects of input price movements, technology changes, capacity utilization and dynamic mechanisms on energy demand structures in the Kenyan industry. This is done with the help of a variant of the second generation dynamic factor demand (econometric) model. This interrelated disequilibrium dynamic input demand econometric model is based on a long-term cost function representing production function possibilities and takes into account the asymmetry between variable inputs (electricity, other-fuels and Tabour) and quasi-fixed input (capital) by imposing restrictions on the adjustment process. Variations in capacity utilization and slow substitution process invoked by the relative input price movement justifies the nature of input demand disequilibrium. The model is estimated on two ISIS digit Kenyan industry time series data (1961 - 1988) using the Iterative Zellner generalized least square method. 31 refs., 8 tabs.

Haji, S.H.H. [Gothenburg Univ. (Sweden)

1994-12-31T23:59:59.000Z

98

Clustering Properties of Dynamical Dark Energy Models  

E-Print Network [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 coupled to dark matter.

P. P. Avelino; L. M. G. Beca; C. J. A. P. Martins

2008-02-01T23:59:59.000Z

99

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

100

Models of Receptive Field Dynamics in Visual Cortex  

E-Print Network [OSTI]

The position, size, and shape of the receptive field (RF) of some cortical neurons change dynamically, in response to artificial scotoma conditioning (Pettet & Gilbert, 1992) and to retinal lesions (Chino et al., 1992; Darian-Smith & Gilbert, 1995) in adult animals. The RF dynamics are of interest because they show how visual systems may adaptively overcome damage (from lesions, scotomas, or other failures), may enhance processing efficiency by altering RF coverage in response to visual demand, and may perform perceptual learning. This paper presents an afferent excitatory synaptic plasticity rule and a lateral inhibitory synaptic plasticity rule -- the EXIN rules (Marshall, 1995a) -- to model persistent RF changes after artificial scotoma conditioning and retinal lesions. The EXIN model is compared to the LISSOM model (Sirosh et al., 1996) and to a neuronal adaptation model (Xing & Gerstein, 1994). The rules within each model are isolated and are analyzed independently, to elucidate t...

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

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

102

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

103

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.

104

Modeling Dynamic Landscapes in Open Source GIS  

E-Print Network [OSTI]

is free online • message board discussion, help • Google sites: post HW, get feedback • register to get credit Solar radiation modeling: monthly totals Applications in urban areas: solar panels, building design, thermal conditions,… Helena Mitasova, NCSU... that is free to run, study, modify and distribute Free means freedom: free is a matter of liberty not price It can be commercial (Red Hat Linux) but not proprietary OSGeo foundation supports the development of open source geospatial software and promotes its...

Mitasova, Helena

2013-11-20T23:59:59.000Z

105

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

106

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

107

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

108

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

109

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.

110

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

111

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

112

Fitting Dynamical Models to Observations of Globular Clusters  

E-Print Network [OSTI]

The basic ingredients of models for the internal dynamics of globular clusters are reviewed, with an emphasis on the description of equilibrium configurations. The development of progressive complexity in the models is traced, concentrating on the inclusion of velocity anisotropy, rotation, and integrals of motion other than energy. Applications to observations of extragalactic globulars and to combined radial-velocity and proper-motion datasets are discussed.

Dean E. McLaughlin

2003-02-14T23:59:59.000Z

113

The Dynamics of Brane-World Cosmological Models  

E-Print Network [OSTI]

Brane-world cosmology is motivated by recent developments in string/M-theory and offers a new perspective on the hierarchy problem. In the brane-world scenario, our Universe is a four-dimensional subspace or {\\em brane} embedded in a higher-dimensional {\\em bulk} spacetime. Ordinary matter fields are confined to the brane while the gravitational field can also propagate in the bulk, leading to modifications of Einstein's theory of general relativity at high energies. In particular, the Randall-Sundrum-type models are self-consistent and simple and allow for an investigation of the essential non-linear gravitational dynamics. The governing field equations induced on the brane differ from the general relativistic equations in that there are nonlocal effects from the free gravitational field in the bulk, transmitted via the projection of the bulk Weyl tensor, and the local quadratic energy-momentum corrections, which are significant in the high-energy regime close to the initial singularity. In this review we discuss the asymptotic dynamical evolution of spatially homogeneous brane-world cosmological models containing both a perfect fluid and a scalar field close to the initial singularity. Using dynamical systems techniques it is found that, for models with a physically relevant equation of state, an isotropic singularity is a past-attractor in all orthogonal spatially homogeneous models (including Bianchi type IX models). In addition, we describe the dynamics in a class of inhomogeneous brane-world models, and show that these models also have an isotropic initial singularity. These results provide support for the conjecture that typically the initial cosmological singularity is isotropic in brane-world cosmology.

A. A. Coley

2005-04-09T23:59:59.000Z

114

Mathematical Modeling of Microbial Community Dynamics: A Methodological Review  

SciTech Connect (OSTI)

Microorganisms in nature form diverse communities that dynamically change in structure and function in response to environmental variations. As a complex adaptive system, microbial communities show higher-order properties that are not present in individual microbes, but arise from their interactions. Predictive mathematical models not only help to understand the underlying principles of the dynamics and emergent properties of natural and synthetic microbial communities, but also provide key knowledge required for engineering them. In this article, we provide an overview of mathematical tools that include not only current mainstream approaches, but also less traditional approaches that, in our opinion, can be potentially useful. We discuss a broad range of methods ranging from low-resolution supra-organismal to high-resolution individual-based modeling. Particularly, we highlight the integrative approaches that synergistically combine disparate methods. In conclusion, we provide our outlook for the key aspects that should be further developed to move microbial community modeling towards greater predictive power.

Song, Hyun-Seob; Cannon, William R.; Beliaev, Alex S.; Konopka, Allan

2014-10-17T23:59:59.000Z

115

Gaussian Process Model for Collision Dynamics of Complex Molecules  

E-Print Network [OSTI]

We show that a Gaussian Process model can be combined with a small number of scattering calculations to provide an accurate multi-dimensional dependence of scattering observables on the experimentally controllable parameters (such as the collision energy, temperature or external fields) as well as the potential energy surface parameters. This can be used for solving the inverse scattering problem, the prediction of collision properties of a specific molecular system based on the information for another molecule, the efficient calculation of thermally averaged observables and for reducing the error of the molecular dynamics calculations by averaging over the potential energy surface variations. We show that, trained by a combination of classical and quantum dynamics calculations, the model provides an accurate description of the scattering cross sections, even near scattering resonances. In this case, the classical calculations stabilize the model against uncertainties arising from wildly varying correlations ...

Cui, Jie

2015-01-01T23:59:59.000Z

116

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.

117

A Dynamic Energy Budget (DEB) model for the energy usage and reproduction of the Icelandic capelin (Mallotus villosus)  

E-Print Network [OSTI]

S.A.L.M. , 2010. Dynamic Energy Budget Theory For Metabolicthe use of dynamic energy budget theory. Biological Reviewsthrough dynamic energy budget models. Jour- nal of Animal

Einarsson, Baldvin; Birnir, Bjorn; Sigurðsson, Sven Þ.

2010-01-01T23:59:59.000Z

118

Dynamics of Matter in a Compactified Kaluza-Klein Model  

E-Print Network [OSTI]

A longstanding problem in Kaluza-Klein models is the description of matter dynamics. Within the 5D model, the dimensional reduction of the geodesic motion for a 5D free test particle formally restores electrodynamics, but the reduced 4D particle shows a charge-mass ratio that is upper bounded, such that it cannot fit to any kind of elementary particle. At the same time, from the quantum dynamics viewpoint, there is the problem of the huge massive modes generation. We present a criticism against the 5D geodesic approach and face the hypothesis that in Kaluza-Klein space the geodesic motion does not deal with the real dynamics of test particle. We propose a new approach: starting from the conservation equation for the 5D matter tensor, within the Papapetrou multipole expansion, we prove that the 5D dynamical equation differs from the 5D geodesic one. Our new equation provides right coupling terms without bounding and in such a scheme the tower of massive modes is removed.

Valentino Lacquaniti; Giovanni Montani

2009-02-10T23:59:59.000Z

119

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

120

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

Dynamical Wave Function Collapse Models in Quantum Measure Theory  

E-Print Network [OSTI]

The structure of Collapse Models is investigated in the framework of Quantum Measure Theory, a histories-based approach to quantum mechanics. The underlying structure of coupled classical and quantum systems is elucidated in this approach which puts both systems on a spacetime footing. The nature of the coupling is exposed: the classical histories have no dynamics of their own but are simply tied, more or less closely, to the quantum histories.

Fay Dowker; Yousef Ghazi-Tabatabai

2008-05-15T23:59:59.000Z

122

Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities  

SciTech Connect (OSTI)

The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

2012-09-01T23:59:59.000Z

123

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

124

Code description: A dynamic modelling strategy for Bayesian computer model emulation  

E-Print Network [OSTI]

Code description: A dynamic modelling strategy for Bayesian computer model emulation 1 Example data and code directory The example data is provided under the directory "mydata": · "design1.dat": this file2.dat": this file contains the 60 validation runs. The Matlab code is provided under the directory

West, Mike

125

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

126

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

127

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

128

Computational fluid dynamic modeling of fluidized-bed polymerization reactors  

SciTech Connect (OSTI)

Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

Rokkam, Ram [Ames Laboratory

2012-11-02T23:59:59.000Z

129

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

130

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.

131

Ultrafast Structural Dynamics Inside Planar Phospholipid Multibilayer Model Cell Membranes Measured with 2D IR  

E-Print Network [OSTI]

Ultrafast Structural Dynamics Inside Planar Phospholipid Multibilayer Model Cell Membranes Measured diffusion caused by the structural dynamics of the membrane from 200 fs to 200 ps as a function structure and an abrupt change in dynamics at 35% cholesterol. The dynamics are independent of cholesterol

Fayer, Michael D.

132

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

133

The Third State of the Schelling Model of Residential Dynamics  

E-Print Network [OSTI]

The Schelling model of segregation between two groups of residential agents (Schelling 1971; Schelling 1978) reflects the most abstract view of the non-economic forces of residential migrations: be close to people of 'your own'. The model assumes that the residential agent, located in the neighborhood where the fraction of 'friends' is less than a predefined threshold value F, tries to relocate to a neighborhood for which this fraction is above F. It is well known that for the equal groups, depending on F, Schelling's residential pattern converges either to complete integration (random pattern) or segregation. We investigate Schelling model pattern dynamics as dependent on F, the ratio of the group numbers and the size of the neighborhood and demonstrate that the traditional integrate-segregate dichotomy is incomplete. In case of unequal groups, there exists the wide interval of the F-values that entails the third persistent residential pattern, in which part of the majority population segregates, while the r...

Benenson, Itzhak

2009-01-01T23:59:59.000Z

134

Mechanical reaction-diffusion model for bacterial population dynamics  

E-Print Network [OSTI]

The effect of mechanical interaction between cells on the spreading of bacterial population was investigated in one-dimensional space. A nonlinear reaction-diffusion equation has been formulated as a model for this dynamics. In this model, the bacterial cells are treated as the rod-like particles that interact, when contacting each other, through the hard-core repulsion. The repulsion introduces the exclusion process that causes the fast diffusion in bacterial population at high density. The propagation of the bacterial density as the traveling wave front in long time behavior has been analyzed. The analytical result reveals that the front speed is enhanced by the exclusion process---and its value depends on the packing fraction of cell. The numerical solutions of the model have been solved to confirm this prediction.

Ngamsaad, Waipot

2015-01-01T23:59:59.000Z

135

A model of riots dynamics: shocks, diffusion and thresholds  

E-Print Network [OSTI]

We introduce and analyze several variants of a system of differential equations which model the dynamics of social outbursts, such as riots. The systems involve the coupling of an explicit variable representing the intensity of rioting activity and an underlying (implicit) field of social tension. Our models include the effects of exogenous and endogenous factors as well as various propagation mechanisms. From numerical and mathematical analysis of these models we show that the assumptions made on how different locations influence one another and how the tension in the system disperses play a major role on the qualitative behavior of bursts of social unrest. Furthermore, we analyze here various properties of these systems, such as the existence of traveling wave solutions, and formulate some new open mathematical problems which arise from our work.

Berestycki, Henri; Rodriguez, Nancy

2015-01-01T23:59:59.000Z

136

Model for Aggregated Water Heater Load Using Dynamic Bayesian Networks  

SciTech Connect (OSTI)

The transition to the new generation power grid, or “smart grid”, requires novel ways of using and analyzing data collected from the grid infrastructure. Fundamental functionalities like demand response (DR), that the smart grid needs, rely heavily on the ability of the energy providers and distributors to forecast the load behavior of appliances under different DR strategies. This paper presents a new model of aggregated water heater load, based on dynamic Bayesian networks (DBNs). The model has been validated against simulated data from an open source distribution simulation software (GridLAB-D). The results presented in this paper demonstrate that the DBN model accurately tracks the load profile curves of aggregated water heaters under different testing scenarios.

Vlachopoulou, Maria; Chin, George; Fuller, Jason C.; Lu, Shuai; Kalsi, Karanjit

2012-07-19T23:59:59.000Z

137

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

138

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

139

Dynamic water wave pressures on a recurved model seawall  

E-Print Network [OSTI]

: Dr. Jerry L. Machemehl The dynamic pressures acting on a I:5 scale recurved model seawall caused by breaking water waves were investigated. The magnitude, location and distribution of the shock and secondary pressures were determined from physical... and incident wave height increased, the magnitude of the shock and secondary pressure increased. Shock pressures as great as 3. 72 kN/m~ were recorded, while a change in water depth of 0. 01m caused a mean pressure increase of approximately 0. 09 k...

Rismiller, Gregory Ross

1989-01-01T23:59:59.000Z

140

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

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

142

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

143

Ice sheets and their dynamics Continuum thermo-mechanical model of a glacier  

E-Print Network [OSTI]

Ice sheets and their dynamics Continuum thermo-mechanical model of a glacier Shallow Ice Approximation (SIA) SIA-I Iterative Improvement Technique Benchmarks Numerical modeling of ice-sheet dynamics and Cartography, Zdiby 1.6.2010 Ondej Soucek Ph.D. defense #12;Ice sheets and their dynamics Continuum thermo

Cerveny, Vlastislav

144

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

145

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.

146

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

147

Modeling Temporal Behavior in Large Networks: A Dynamic Mixed-Membership Model  

SciTech Connect (OSTI)

Given a large time-evolving network, how can we model and characterize the temporal behaviors of individual nodes (and network states)? How can we model the behavioral transition patterns of nodes? We propose a temporal behavior model that captures the 'roles' of nodes in the graph and how they evolve over time. The proposed dynamic behavioral mixed-membership model (DBMM) is scalable, fully automatic (no user-defined parameters), non-parametric/data-driven (no specific functional form or parameterization), interpretable (identifies explainable patterns), and flexible (applicable to dynamic and streaming networks). Moreover, the interpretable behavioral roles are generalizable, computationally efficient, and natively supports attributes. We applied our model for (a) identifying patterns and trends of nodes and network states based on the temporal behavior, (b) predicting future structural changes, and (c) detecting unusual temporal behavior transitions. We use eight large real-world datasets from different time-evolving settings (dynamic and streaming). In particular, we model the evolving mixed-memberships and the corresponding behavioral transitions of Twitter, Facebook, IP-Traces, Email (University), Internet AS, Enron, Reality, and IMDB. The experiments demonstrate the scalability, flexibility, and effectiveness of our model for identifying interesting patterns, detecting unusual structural transitions, and predicting the future structural changes of the network and individual nodes.

Rossi, R; Gallagher, B; Neville, J; Henderson, K

2011-11-11T23:59:59.000Z

148

Quantum Dynamics of the Driven and Dissipative Rabi Model  

E-Print Network [OSTI]

The Rabi model considers a two-level system (or spin-1/2) coupled to a quantized harmonic oscillator and describes the simplest interaction between matter and light. The recent experimental progress in solid-state circuit quantum electrodynamics has engendered theoretical efforts to quantitatively describe the mathematical and physical aspects of the light-matter interaction beyond the rotating wave approximation. We develop a stochastic Schr\\"{o}dinger equation approach which enables us to access the strong-coupling limit of the Rabi model and study the effects of dissipation, and AC drive in an exact manner. We include the effect of ohmic noise on the non-Markovian spin dynamics resulting in Kondo-type correlations, as well as cavity losses. We compute the time evolution of spin variables in various conditions. As a consideration for future work, we discuss the possibility to reach a steady state with one polariton in realistic experimental conditions.

Loïc Henriet; Zoran Ristivojevic; Peter P. Orth; Karyn Le Hur

2014-08-15T23:59:59.000Z

149

Examination of temporal DDT trends in Lake Erie fish communities using dynamic linear modeling  

E-Print Network [OSTI]

Examination of temporal DDT trends in Lake Erie fish communities using dynamic linear modeling 25 July 2013 Communicated by Dr. Erik Christensen Keywords: DDT Bayesian inference Dynamic linear (DDT) was initially heralded for its effectiveness against malaria and agricultural pests

Arhonditsis, George B.

150

Model Studies of the Dynamics of Bacterial Flagellar Motors  

SciTech Connect (OSTI)

The Bacterial Flagellar Motor is a rotary molecular machine that rotates the helical filaments which propel swimming bacteria. Extensive experimental and theoretical studies exist on the structure, assembly, energy input, power generation and switching mechanism of the motor. In our previous paper, we explained the general physics underneath the observed torque-speed curves with a simple two-state Fokker-Planck model. Here we further analyze this model. In this paper we show (1) the model predicts that the two components of the ion motive force can affect the motor dynamics differently, in agreement with the latest experiment by Lo et al.; (2) with explicit consideration of the stator spring, the model also explains the lack of dependence of the zero-load speed on stator number in the proton motor, recently observed by Yuan and Berg; (3) the model reproduces the stepping behavior of the motor even with the existence of the stator springs and predicts the dwelling time distribution. Predicted stepping behavior of motors with two stators is discussed, and we suggest future experimental verification.

Bai, F; Lo, C; Berry, R; Xing, J

2009-03-19T23:59:59.000Z

151

The Dynamically Extended Mind -- A Minimal Modeling Case Study  

E-Print Network [OSTI]

The extended mind hypothesis has stimulated much interest in cognitive science. However, its core claim, i.e. that the process of cognition can extend beyond the brain via the body and into the environment, has been heavily criticized. A prominent critique of this claim holds that when some part of the world is coupled to a cognitive system this does not necessarily entail that the part is also constitutive of that cognitive system. This critique is known as the "coupling-constitution fallacy". In this paper we respond to this reductionist challenge by using an evolutionary robotics approach to create a minimal model of two acoustically coupled agents. We demonstrate how the interaction process as a whole has properties that cannot be reduced to the contributions of the isolated agents. We also show that the neural dynamics of the coupled agents has formal properties that are inherently impossible for those neural networks in isolation. By keeping the complexity of the model to an absolute minimum, we are able to illustrate how the coupling-constitution fallacy is in fact based on an inadequate understanding of the constitutive role of nonlinear interactions in dynamical systems theory.

Tom Froese; Carlos Gershenson; David A. Rosenblueth

2013-05-08T23:59:59.000Z

152

Can a more realistic model error structure improve the parameter estimation in modelling the dynamics of sh populations?  

E-Print Network [OSTI]

or applying an estimation method that is robust to the error structure assumption in modelling the dynamicsCan a more realistic model error structure improve the parameter estimation in modelling the dynamics of ®sh populations? Y. Chena,* , J.E. Paloheimob a Fisheries Conservation Chair Program, Fisheries

Chen, Yong

153

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

154

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

155

Dynamic first-order phase transition in kinetically constrained models of glasses  

E-Print Network [OSTI]

We show that the dynamics of kinetically constrained models of glass formers takes place at a first-order coexistence line between active and inactive dynamical phases. We prove this by computing the large-deviation functions of suitable space-time observables, such as the number of configuration changes in a trajectory. We present analytic results for dynamic facilitated models in a mean-field approximation, and numerical results for the Fredrickson-Andersen model, the East model, and constrained lattice gases, in various dimensions. This dynamical first-order transition is generic in kinetically constrained models, and we expect it to be present in systems with fully jammed states.

J. P. Garrahan; R. L. Jack; V. Lecomte; E. Pitard; K. van Duijvendijk; F. van Wijland

2007-05-22T23:59:59.000Z

156

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

157

Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems  

E-Print Network [OSTI]

Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems Hae-woo Park Kyoungjoo Oh of synchronous data-flow (SDF) ­modeled program for low-end embedded systems which lack MMU- support-program code, dynamic loader and linker script files from the given SDF- modeled blocks and schematic, so we

Ha, Soonhoi

158

Capacitive effect of cavitation in xylem conduits: results from a dynamic model  

E-Print Network [OSTI]

Capacitive effect of cavitation in xylem conduits: results from a dynamic model TEEMU HÃ?LTTÃ?1. A dynamic model is presented that models xylem water potential, xylem sap flow and cavitation, taking; xylem transport. INTRODUCTION Xylem embolism formation by cavitation causes a decrease in plant

Mencuccini, Maurizio

159

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

160

Tyre modelling for use in vehicle dynamics studies  

SciTech Connect (OSTI)

A new way of representing tyre data obtained from measurements in pure cornering and pure braking conditions has been developed in order to further improve the Dynamic Safety of vehicles. The method makes use of a formula with coefficients which describe some of the typifying quantities of a tyre, such as slip stiffnesses at zero slip and force and torque peak values. The formula is capable of describing the characteristics of side force, brake force and self aligning torque with great accuracy. This mathematical representation is limited to steady-state conditions during either pure cornering or pure braking and forms the basis for a model describing tyre behaviour during combined braking and cornering.

Bakker, E.; Nyborg, L.; Pacejka, H.B.

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Hydro-dynamical models for the chaotic dripping faucet  

E-Print Network [OSTI]

We give a hydrodynamical explanation for the chaotic behaviour of a dripping faucet using the results of the stability analysis of a static pendant drop and a proper orthogonal decomposition (POD) of the complete dynamics. We find that the only relevant modes are the two classical normal forms associated with a Saddle-Node-Andronov bifurcation and a Shilnikov homoclinic bifurcation. This allows us to construct a hierarchy of reduced order models including maps and ordinary differential equations which are able to qualitatively explain prior experiments and numerical simulations of the governing partial differential equations and provide an explanation for the complexity in dripping. We also provide a new mechanical analogue for the dripping faucet and a simple rationale for the transition from dripping to jetting modes in the flow from a faucet.

P. Coullet; L. Mahadevan; C. S. Riera

2004-08-20T23:59:59.000Z

162

Dynamic Markov bridges motivated by models of insider trading  

E-Print Network [OSTI]

Given a Markovian Brownian martingale $Z$, we build a process $X$ which is a martingale in its own filtration and satisfies $X_1 = Z_1$. We call $X$ a dynamic bridge, because its terminal value $Z_1$ is not known in advance. We compute explicitly its semimartingale decomposition under both its own filtration $\\cF^X$ and the filtration $\\cF^{X,Z}$ jointly generated by $X$ and $Z$. Our construction is heavily based on parabolic PDE's and filtering techniques. As an application, we explicitly solve an equilibrium model with insider trading, that can be viewed as a non-Gaussian generalization of Back and Pedersen's \\cite{BP}, where insider's additional information evolves over time.

Campi, Luciano; Danilova, Albina

2012-01-01T23:59:59.000Z

163

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

164

Shear band dynamics from a mesoscopic modeling of plasticity  

E-Print Network [OSTI]

The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.

E. A. Jagla

2010-06-07T23:59:59.000Z

165

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

166

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

167

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

168

Calibration of Reduced Dynamic Models of Power Systems using Phasor Measurement Unit (PMU) Data  

SciTech Connect (OSTI)

Accuracy of a power system dynamic model is essential to the secure and efficient operation of the system. Lower confidence on model accuracy usually leads to conservative operation and lowers asset usage. To improve model accuracy, identification algorithms have been developed to calibrate parameters of individual components using measurement data from staged tests. To facilitate online dynamic studies for large power system interconnections, this paper proposes a model reduction and calibration approach using phasor measurement unit (PMU) data. First, a model reduction method is used to reduce the number of dynamic components. Then, a calibration algorithm is developed to estimate parameters of the reduced model. This approach will help to maintain an accurate dynamic model suitable for online dynamic studies. The performance of the proposed method is verified through simulation studies.

Zhou, Ning; Lu, Shuai; Singh, Ruchi; Elizondo, Marcelo A.

2011-09-23T23:59:59.000Z

169

Shell Model Dynamics of HCl on the MgO(001) Surface Terrace Andreas Markmann,1  

E-Print Network [OSTI]

are then used to aid the analysis of MD calculations. After equilibrium dynamics, a sudden excitation of the OH of molecular dynamics using specially tailored laser fields. The reaction of hydrogen chloride moleculesShell Model Dynamics of HCl on the MgO(001) Surface Terrace Andreas Markmann,1 Jacob L. Gavartin,2

Markmann, Andreas

170

Idealized test cases for the dynamical cores of Atmospheric General Circulation Models  

E-Print Network [OSTI]

Idealized test cases for the dynamical cores of Atmospheric General Circulation Models: A proposal) Ram Nair (NCAR) Mark Taylor (Sandia National Laboratory) May/29/2008 1 Idealized test cases for 3D dynamical cores This document describes the idealized dynamical core test cases that are proposed

Jablonowski, Christiane

171

Physica D 159 (2001) 3557 Wave group dynamics in weakly nonlinear long-wave models  

E-Print Network [OSTI]

Physica D 159 (2001) 35­57 Wave group dynamics in weakly nonlinear long-wave models Roger Grimshawa Communicated by A.C. Newell Abstract The dynamics of wave groups is studied for long waves, using the framework reserved. Keywords: Wave group dynamics; Korteweg­de Vries equation; Nonlinear Schr¨odinger equation 1

Pelinovsky, Dmitry

172

109J.D. Westervelt and G.L. Cohen (eds.), Ecologist-Developed Spatially Explicit Dynamic Landscape Models, Modeling Dynamic Systems,  

E-Print Network [OSTI]

Models, Modeling Dynamic Systems, DOI 10.1007/978-1-4614-1257-1_7, © Springer Science+Business Media, LLC, these targets should represent the most efficient use of limited resources, especially given that resource managers need to balance multiple, often complex issues (Reed et al. 2009). Population models can often aid

Georgia, University of

173

A spatially structured metapopulation model with patch dynamics  

E-Print Network [OSTI]

Sep 30, 2005 ... creation) and metapopulation dynamics (patch colonization and extinction). ... genetic structure (Gaines and Lyons, 1997), and commu-.

2007-08-22T23:59:59.000Z

174

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

175

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

176

Dynamic Transitions in a Two Dimensional Associating Lattice Gas Model  

E-Print Network [OSTI]

Using Monte Carlo simulations we investigate some new aspects of the phase diagram and the behavior of the diffusion coefficient in an associating lattice gas (ALG) model on different regions of the phase diagram. The ALG model combines a two dimensional lattice gas where particles interact through a soft core potential and orientational degrees of freedom. The competition between soft core potential and directional attractive forces results in a high density liquid phase, a low density liquid phase, and a gas phase. Besides anomalies in the behavior of the density with the temperature at constant pressure and of the diffusion coefficient with density at constant temperature are also found. The two liquid phases are separated by a coexistence line that ends in a bicritical point. The low density liquid phase is separated from the gas phase by a coexistence line that ends in tricritical point. The bicritical and tricritical points are linked by a critical $\\lambda$-line. The high density liquid phase and the fluid phases are separated by a second $\\tau$ critical line. We then investigate how the diffusion coefficient behaves on different regions of the chemical potential-temperature phase diagram. We find that diffusivity undergoes two types of dynamic transitions: a fragile-to-strong trans ition when the critical $\\lambda$-line is crossed by decreasing the temperature at a constant chemical potential; and a strong-to-strong transition when the $\\tau$-critical line is crossed by decreasing the temperature at a constant chemical potential.

Marcia M. Szortyka; Vera Henriques; Mauricio Girardi; Marcia C. Barbosa

2009-02-10T23:59:59.000Z

177

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

178

Optimal foreign borrowing in a multisector dynamic equilibrium model for Brazil  

E-Print Network [OSTI]

This paper shows how a dynamic multisector equilibrium model can be formulated to be able to analyze the optimal borrowing policy of a developing country. It also describes how a non-linear programming model with the ...

Tourinho, Octv?io A. F.

1985-01-01T23:59:59.000Z

179

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

180

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

Note: This page contains sample records for the topic "dynamics model redyn" 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

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

182

age-structured dynamical models: Topics by E-print Network  

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

does not migrate. Le, Thuc Manh; Van Minh, Nguyen 2010-01-01 36 Galactic Nonlinear Dynamic Model Mathematical Physics (arXiv) Summary: We develop a model for spiral galaxies...

183

New methods for estimation, modeling and validation of dynamical systems using automatic differentiation  

E-Print Network [OSTI]

equations, for a class of nonlinear dynamical systems. In the area of trajectory optimization some new ideas are presented for automating the process of deriving co- state differential equations. Additionally, higher-order algorithms for computing... midcourse corrections are introduced. In Chapter IV, some new insights into modeling of dynamical systems are presented. Producing dynamical models in the form of coupled nonlinear differential equations is a frequent first step for analysis, estimation...

Griffith, Daniel Todd

2005-02-17T23:59:59.000Z

184

Currents and turbulence within a kelp forest (Macrocystis pyrifera): Insights from a dynamically scaled laboratory model  

E-Print Network [OSTI]

Currents and turbulence within a kelp forest (Macrocystis pyrifera): Insights from a dynamically a dynamically matched 1/25-scale model. Two kelp configurations with surface canopies and one without a surface acoustic Doppler velocimeters. Since flow within the model kelp forest was very heterogeneous, spatially

Denny, Mark

185

NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING  

E-Print Network [OSTI]

NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING H. A. Ai1 , T. J beneath impact crater in granite. Model constants are determined either directly from static uniaxial from Century Dynamics to simulate the shock-induced damage in granite targets impacted by projectiles

Stewart, Sarah T.

186

Dynamic Versus Steady-State Modeling of FACTS Controllers in Transmission Congestion  

E-Print Network [OSTI]

benchmark system is used to illustrate and compare the effect on locational marginal prices and transmission marginal prices obtained from stability-constrained auction models when dynamic and steady state FACTS discusses the effect on transmission congestion management and pricing of dynamic and steady- state models

Cañizares, Claudio A.

187

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

188

A model for dynamic chance constraints in hydro power reservoir management  

E-Print Network [OSTI]

A model for dynamic chance constraints in hydro power reservoir management L. Andrieu , R. Henrion In this paper, a model for (joint) dynamic chance constraints is proposed and ap- plied to an optimization for two and three stages. 1 Introduction A conventional optimization problem under chance constraints

Römisch, Werner

189

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

190

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 is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film

Paris-Sud XI, Université de

191

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

192

Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed)  

E-Print Network [OSTI]

Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed) Maurice, continuous-time modeling allows application of a powerful mathematical tool, the theory of optimal dynamic control. The basic idea of optimal control theory is easy to grasp-- indeed it follows from elementary

Sadoulet, Elisabeth

193

A differentiable dynamic network loading model that yields queue length distributions and accounts for spillback  

E-Print Network [OSTI]

A differentiable dynamic network loading model that yields queue length distributions and accounts, this is so because the kinematic wave model (KWM), the mainstay of traffic flow theory, only applies for spillback Carolina Osorio Gunnar Fl¨otter¨od Michel Bierlaire Abstract We derive a dynamic network

Bierlaire, Michel

194

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

195

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

196

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

197

Integrated dynamic landscape analysis and modeling system (IDLAMS) : installation manual.  

SciTech Connect (OSTI)

The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) is a prototype, integrated land management technology developed through a joint effort between Argonne National Laboratory (ANL) and the US Army Corps of Engineers Construction Engineering Research Laboratories (USACERL). Dr. Ronald C. Sundell, Ms. Pamela J. Sydelko, and Ms. Kimberly A. Majerus were the principal investigators (PIs) for this project. Dr. Zhian Li was the primary software developer. Dr. Jeffrey M. Keisler, Mr. Christopher M. Klaus, and Mr. Michael C. Vogt developed the decision analysis component of this project. It was developed with funding support from the Strategic Environmental Research and Development Program (SERDP), a land/environmental stewardship research program with participation from the US Department of Defense (DoD), the US Department of Energy (DOE), and the US Environmental Protection Agency (EPA). IDLAMS predicts land conditions (e.g., vegetation, wildlife habitats, and erosion status) by simulating changes in military land ecosystems for given training intensities and land management practices. It can be used by military land managers to help predict the future ecological condition for a given land use based on land management scenarios of various levels of training intensity. It also can be used as a tool to help land managers compare different land management practices and further determine a set of land management activities and prescriptions that best suit the needs of a specific military installation.

Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.

1999-02-24T23:59:59.000Z

198

Integrated dynamic landscape analysis and modeling system (IDLAMS) : programmer's manual.  

SciTech Connect (OSTI)

The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) is a prototype, integrated land management technology developed through a joint effort between Argonne National Laboratory (ANL) and the US Army Corps of Engineers Construction Engineering Research Laboratories (USACERL). Dr. Ronald C. Sundell, Ms. Pamela J. Sydelko, and Ms. Kimberly A. Majerus were the principal investigators (PIs) for this project. Dr. Zhian Li was the primary software developer. Dr. Jeffrey M. Keisler, Mr. Christopher M. Klaus, and Mr. Michael C. Vogt developed the decision analysis component of this project. It was developed with funding support from the Strategic Environmental Research and Development Program (SERDP), a land/environmental stewardship research program with participation from the US Department of Defense (DoD), the US Department of Energy (DOE), and the US Environmental Protection Agency (EPA). IDLAMS predicts land conditions (e.g., vegetation, wildlife habitats, and erosion status) by simulating changes in military land ecosystems for given training intensities and land management practices. It can be used by military land managers to help predict the future ecological condition for a given land use based on land management scenarios of various levels of training intensity. It also can be used as a tool to help land managers compare different land management practices and further determine a set of land management activities and prescriptions that best suit the needs of a specific military installation.

Klaus, C. M.; Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.

1999-02-24T23:59:59.000Z

199

The modeling of aerosol dynamics during degraded core events  

SciTech Connect (OSTI)

There is substantial interest in developing simple, yet accurate, models for the prediction of aerosol dynamics during degraded core events. The exact aerosol transport equation is given by {partial derivative}n(v,t)/{partial derivative}t = 1/2 {integral}{sub 0}{sup {infinity}} K(u,v {minus} u)n(u,t)n(v {minus} u,t)du {minus} {integral}{sub 0}{sup {infinity}} K(u,v)n(v,t)n(u,t)du {minus} n(v,t)c(v)/h + n{sub p}(v), where n(v,t) is the particle size density distribution function. The kernel, K(v,u), is related to the frequency of coagulation between aerosol particles of volume u and v, and the quantity c(v) is the deposition velocity. The quantity h is the effective height for deposition of aerosol; it is the volume of the aerosol cloud divided by the projected horizontal area A. Finally, the term n{sub p} (v) is the source rate of aerosol. Evaluation of the above equation is discussed.

Clausse, A.; Lahey, R.T. Jr.

1989-01-01T23:59:59.000Z

200

Dynamics of an age-structured metapopulation model  

E-Print Network [OSTI]

address the temporal dynamics that characterize local popu- lations in ... this metapopulation framework, two structures have emerged as being critical in the ...

2005-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

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.

202

A Business Model Framework for Dynamic Spectrum Access in Cognitive Networks  

E-Print Network [OSTI]

A Business Model Framework for Dynamic Spectrum Access in Cognitive Networks Nikhil Kelkar, Dr implement these technologies and still profit from them? III. FUNDAMENTAL MODEL The business model which we a multi-parameter approach by defining four levels on which everyday business models operate. Value

Ha, Dong S.

203

BIOMECHANICAL ANALYSIS OF TWO SIMPLE DYNAMICAL MODELS FOR THE HUMAN GAIT  

E-Print Network [OSTI]

and expenditure energy for the human body in normal walking models. Both models allow us to adapt a vector the adaptability of the subject to the environment in a reactive way . The high complexity of biomechanical modelsBIOMECHANICAL ANALYSIS OF TWO SIMPLE DYNAMICAL MODELS FOR THE HUMAN GAIT J.Finat1 , F.Montoya2

Llanos, Diego R.

204

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

205

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-Print Network [OSTI]

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic of multi-megawatt turbines requires a new generation of modeling capability to assess individual turbine. Key Result The work is generating several models, including actuator line models of several wind

206

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

207

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

208

Nonlinear Modeling of the Dynamic Effects of Infused Insulin on Glucose: Comparison of Compartmental With Volterra Models  

E-Print Network [OSTI]

This paper presents the results of a computational study that compares simulated compartmental (differential equation) and Volterra models of the dynamic effects of insulin on blood glucose concentration in humans. In the ...

Markakis, Michail

209

Comparing partial-wave amplitude parametrization with dynamical models of meson-nucleon scattering  

E-Print Network [OSTI]

Relationships between partial-wave amplitude parametrizations, in particular the Chew-Mandelstam approach, and dynamical coupled-channel models are established and investigated. A bare pole corresponding to the Delta(1232) resonance, found in a recent dynamical-model fit to pion- and omega-meson production reactions, compares closely to one found in a unitary multichannel partial-wave amplitude parametrization of SAID. The model dependence of the bare pole precludes a direct connection between the approaches but is suggestive that the dynamical description and the phenomenological parametrization are closely related.

Mark W. Paris; Ron L. Workman

2011-02-28T23:59:59.000Z

210

Modeling the dynamics and depositional patterns of sandy rivers  

E-Print Network [OSTI]

This thesis seeks to advance our understanding of the dynamic nature, spatial organization and depositional record of topography in sand-bedded rivers. I examine patterns and processes over a wide range of scales, on Earth ...

Jerolmack, Douglas J

2006-01-01T23:59:59.000Z

211

SIMULATING MARKET TRANSFORMATION DYNAMICS USING A HYBRID ENERGY ECONOMY MODEL  

E-Print Network [OSTI]

AT THE ADOPTION OF HYDROGEN FUEL CELL VEHICLES by Jimena Eyzaguirre M.Sc. Geology, University of Western Ontario, to develop policy-relevant information about dynamics in consumer preferences for hydrogen fuel cell vehicles

212

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

213

Isomorphic classical molecular dynamics model for an excess electronin a supercritical fluid  

SciTech Connect (OSTI)

Ring polymer molecular dynamics (RPMD) is used to directly simulate the dynamics of an excess electron in a supercritical fluid over a broad range of densities. The accuracy of the RPMD model is tested against numerically exact path integral statistics through the use of analytical continuation techniques. At low fluid densities, the RPMD model substantially underestimates the contribution of delocalized states to the dynamics of the excess electron. However, with increasing solvent density, the RPMD model improves, nearly satisfying analytical continuation constraints at densities approaching those of typical liquids. In the high density regime, quantum dispersion substantially decreases the self-diffusion of the solvated electron. In this regime where the dynamics of the electron is strongly coupled to the dynamics of the atoms in the fluid, trajectories that can reveal diffusive motion of the electron are long in comparison to {beta}{h_bar}.

Miller III, Thomas F.

2008-08-04T23:59:59.000Z

214

Dynamics of the UK Natural Gas Industry: System Dynamics Modelling and Long-Term Energy Policy Analysis  

E-Print Network [OSTI]

www.eprg.group.cam.ac.uk E P R G W O R K IN G P A P E R N O N -T E C H N IC A L S U M M A R Y DYNAMICS OF THE UK NATURAL GAS INDUSTRY: SYSTEM DYNAMICS MODELLING AND LONG-TERM ENERGY POLICY ANALYSIS EPRG Working Paper 0913... Cambridge Working Paper in Economics 0922 Kong Chyong Chi , David M. Reiner and William J. Nuttall The UK offshore natural gas and oil industry has a long and successful history and has been said to represent the pride of UK...

Chi, K C; Reiner, David; Nuttall, William J

215

Brownian Dynamics Model of Excited-State Relaxation in Solutions of Conjugated Oligomers  

E-Print Network [OSTI]

1 Brownian Dynamics Model of Excited-State Relaxation in Solutions of Conjugated Oligomers Nicolae, Pittsburgh, Pennsylvania 15213. Excited state relaxation, conjugated polymers, Brownian dynamics. The effects, of the oligomer. A simple molecular mechanical form is used for the ground electronic state. The excitation energy

Yaron, David

216

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

E-Print Network [OSTI]

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

217

Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow  

E-Print Network [OSTI]

Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow W.B. Gu and C.Y. Wang GATE Center of Excellence for Advanced Energy Storage Department of Mechanical are performed using a finite volume method of computational fluid dynamics. The predicted discharge curves

Wang, Chao-Yang

218

Dynamic Phasor Modeling of the Doubly-Fed Induction Machine in Generator Operation Emmanuel Delaleau*  

E-Print Network [OSTI]

Dynamic Phasor Modeling of the Doubly-Fed Induction Machine in Generator Operation Emmanuel at variable speed; second, the excitation power electronics converter feeding the rotor windings needs of the doubly- fed induction machine in generator operation using dynamic phasors. This concept is coming from

Stankoviæ, Aleksandar

219

Gurson's plasticity coupled to damage as a CAP model for concrete compaction in dynamics  

E-Print Network [OSTI]

1 Gurson's plasticity coupled to damage as a CAP model for concrete compaction in dynamics Fabrice (compaction) but also the plastic strains in compression and cracking in tension. Recently, new dynamic is generally described by means of the plasticity theory where the spherical and the deviatoric responses

220

Integrated Dynamic Optimization and Control in Reservoir Engineering using Locally Identified Linear Models  

E-Print Network [OSTI]

on dynamic real-time optimization (D- RTO) of waterflooding strategies in petroleum reservoirs haveIntegrated Dynamic Optimization and Control in Reservoir Engineering using Locally Identified, the used large-scale, nonlinear, physics-based reservoir models suffer from vast parametric uncertainty

Van den Hof, Paul

Note: This page contains sample records for the topic "dynamics model redyn" 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

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

E-Print Network [OSTI]

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

Pedram, Massoud

222

From Structure to Dynamics: Modeling Exciton Dynamics in the Photosynthetic Antenna B. Bru1ggemann, K. Sznee, V. Novoderezhkin, R. van Grondelle, and V. May*,  

E-Print Network [OSTI]

complemented by various experiments focusing on the dynamics of excitation energy transfer and relaxation afterFrom Structure to Dynamics: Modeling Exciton Dynamics in the Photosynthetic Antenna PS1 B. Bru1 of Sciences and Institute of Molecular Biological Sciences, Vrije UniVersiteit, De Boelelaan 1081, 1081 HV

Röder, Beate

223

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

E-Print Network [OSTI]

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

Gaddamanugu, Dhatri

2010-07-14T23:59:59.000Z

224

Optimal motion planning with the half-car dynamical model for autonomous high-speed driving  

E-Print Network [OSTI]

We discuss an implementation of the RRT* optimal motion planning algorithm for the half-car dynamical model to enable autonomous high-speed driving. To develop fast solutions of the associated local steering problem, we ...

Jeon, Jeong hwan

225

Critical enhancements of a dynamic traffic assignment model for highly congested, complex urban network  

E-Print Network [OSTI]

To accurately replicate the highly congested traffic situation of a complex urban network, significant challenges are posed to current simulation-based dynamic traffic assignment (DTA) models. This thesis discusses these ...

Wei, Zheng, S.M. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

226

Branching patterns emerge in a mathematical model of the dynamics of lung development  

E-Print Network [OSTI]

fluid pressure and fluid–mechanical interactions. Lubarsky &The absence of fluid or mechanical effects may also ex-model to the mechanical and fluid dynamical factors in lung

2014-01-01T23:59:59.000Z

227

The Effect of Model Parameters on the Simulation of Fire Dynamics   

E-Print Network [OSTI]

The sensitivity of computer fire modelling using results from NIST’s Fire Dynamics Simulator (FDS) to a set of input parameters related to fire growth has been analyzed. The scenario simulated is the real-scale Dalmarnock ...

Jahn, Wolfram; Rein, Guillermo; Torero, Jose L

2008-01-01T23:59:59.000Z

228

Coupled Modeling of Dynamic Reservoir/Well Interactions under Liquid-loading Conditions  

E-Print Network [OSTI]

backpressure on the formation, which decreases the gas production rate and may stop the well from flowing. To model these phenomena, the dynamic interaction between the reservoir and the wellbore must be characterized. Due to wellbore phase re...

Limpasurat, Akkharachai

2013-10-23T23:59:59.000Z

229

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

Open Energy Info (EERE)

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

230

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

E-Print Network [OSTI]

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

Sheng, Hongyan

1999-01-01T23:59:59.000Z

231

A scalable computational approach for modeling dynamic fracture of brittle solids in three dimensions  

E-Print Network [OSTI]

In this thesis a new parallel computational method is proposed for modeling threedimensional dynamic fracture of brittle solids. The method is based on a combination of the discontinuous Galerkin (DG) formulation of the ...

Seagraves, Andrew Nathan

2010-01-01T23:59:59.000Z

232

Building Dynamic Models of Service Compositions with Simulation of Provision Resources  

E-Print Network [OSTI]

Building Dynamic Models of Service Compositions with Simulation of Provision Resources Dragan compositions depends both on the composition structure, and on planning and management of compu- tational resources necessary for provision. Resource constraints on the service provider side have impact

Dustdar, Schahram

233

Learning Dynamic Models of Compartment Systems by Combining Symbolic Regression with Fuzzy Vector  

E-Print Network [OSTI]

. Categories and Subject Descriptors I.2.1 [Pattern Recognition]: Models--Fuzzy Set; I.2.6 [ArtificialLearning Dynamic Models of Compartment Systems by Combining Symbolic Regression with Fuzzy Vector and fuzzy represen- tation. We need differential capabilities because, in a dy- namic environment, models

Fernandez, Thomas

234

From "Stages" of Business Growth to a Dynamic States Model of Entrepreneurial Growth and Change  

E-Print Network [OSTI]

From "Stages" of Business Growth to a Dynamic States Model of Entrepreneurial Growth and Change and Gumpert, 1985), and virtually all economic models of business creation follow firm birth with firm growth models of new business growth assume a limited number of distinct stages through #12;3 which businesses

Mottram, Nigel

235

Dynamics of the Oil Transition: Modeling Capacity, Costs, and Emissions  

E-Print Network [OSTI]

market, allowing our model to focus on the supply of crude oil andterms of the model equations [7]). The oil market in ROMEO

Brandt, Adam R.; Farrell, Alexander E.

2008-01-01T23:59:59.000Z

236

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

SciTech Connect (OSTI)

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

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

2013-05-01T23:59:59.000Z

237

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

E-Print Network [OSTI]

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

Kimmich, Mark Raymond

1987-01-01T23:59:59.000Z

238

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

239

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

240

Prof. Alessandro De Luca Dynamic model of robots  

E-Print Network [OSTI]

, identification, uses #12;Analysis of inertial couplings ! Cartesian robot ! Cartesian "skew" robot ! PR robot ! 2 advantage for the design of a motion control law! (*) structural condition in mechanical design Robotics 2 8 in the mechanical design lead to g(q) 0!! Robotics 2 9 #12;Adding dynamic terms ... ! dissipative phenomena due

De Luca, Alessandro

Note: This page contains sample records for the topic "dynamics model redyn" 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

Chapter 18: Understanding the Developing Cellulosic Biofuels Industry through Dynamic Modeling  

SciTech Connect (OSTI)

The purpose of this chapter is to discuss a system dynamics model called the Biomass Scenario Model (BSM), which is being developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the burgeoning cellulosic biofuels industry in the United States. The model has also recently been expanded to include advanced conversion technologies and biofuels (i.e., conversion pathways that yield biomass-based gasoline, diesel, jet fuel, and butanol), but we focus on cellulosic ethanol conversion pathways here. The BSM uses a system dynamics modeling approach (Bush et al., 2008) built on the STELLA software platform.

Newes, E.; Inman, D.; Bush, B.

2011-01-01T23:59:59.000Z

242

Modeling Spike Trains from Area This chapter describes the application of a motion energy model to the dynamic dot  

E-Print Network [OSTI]

74 Chapter 6 Modeling Spike Trains from Area MT This chapter describes the application of a motion energy model to the dynamic dot stimulus. We wanted to know whether the precise temporal modulation widely compared to electrophysiological data from both area MT and its V1 inputs (Heeger, 1987; Grzywacz

Bair, Wyeth

243

Dynamic Model Validation of PV Inverters Under Short-Circuit Conditions: Preprint  

SciTech Connect (OSTI)

Photovoltaic (PV) modules have dramatically decreased in price in the past few years, spurring the expansion of photovoltaic deployment. Residential and commercial rooftop installations are connected to the distribution network; large-scale installation PV power plants (PVPs) have benefited from tax incentives and the low cost of PV modules. As the level penetration of PV generation increases, the impact on power system reliability will also be greater. Utility power system planners must consider the role of PV generation in power systems more realistically by representing PV generation in dynamic stability analyses. Dynamic models of PV inverters have been developed in the positive sequence representation. NREL has developed a PV inverter dynamic model in PSCAD/EMTDC. This paper validates the dynamic model with an actual hardware bench test conducted by Southern California Edison's Distributed Energy Resources laboratory. All the fault combinations -- symmetrical and unsymmetrical -- were performed in the laboratory. We compare the simulation results with the bench test results.

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

2013-03-01T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

245

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

SciTech Connect (OSTI)

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

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

2009-08-01T23:59:59.000Z

246

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

247

Pricing Bivariate Option under GARCH-GH Model with Dynamic Copula: Application for  

E-Print Network [OSTI]

Pricing Bivariate Option under GARCH-GH Model with Dynamic Copula: Application for Chinese Market D Heteroskedastic (GARCH) process. In order to provide a general framework being able to accommodate skewness by the GARCH-GH model with time-varying copula differ substantially from the prices implied by the GARCH

Paris-Sud XI, Université de

248

Modelling propagation of sinkhole, in both slow and dynamic modes, using the UDEC computer code.  

E-Print Network [OSTI]

Modelling propagation of sinkhole, in both slow and dynamic modes, using the UDEC computer code RISques) : Adresse* : Ecole des mines de Nancy, Parc de Saurupt, 54042 Nancy-Cedex, France ; Adresse sinkhole forms and to propose a prediction model. The UDEC code is used. An actual case of sinkhole

Paris-Sud XI, Université de

249

Generalized models as a universal approach to the analysis of nonlinear dynamical systems  

E-Print Network [OSTI]

We present a universal approach to the investigation of the dynamics in generalized models. In these models the processes that are taken into account are not restricted to specific functional forms. Therefore a single generalized models can describe a class of systems which share a similar structure. Despite this generality, the proposed approach allows us to study the dynamical properties of generalized models efficiently in the framework of local bifurcation theory. The approach is based on a normalization procedure that is used to identify natural parameters of the system. The Jacobian in a steady state is then derived as a function of these parameters. The analytical computation of local bifurcations using computer algebra reveals conditions for the local asymptotic stability of steady states and provides certain insights on the global dynamics of the system. The proposed approach yields a close connection between modelling and nonlinear dynamics. We illustrate the investigation of generalized models by considering examples from three different disciplines of science: a socio-economic model of dynastic cycles in china, a model for a coupled laser system and a general ecological food web.

Thilo Gross; Ulrike Feudel

2006-01-29T23:59:59.000Z

250

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

E-Print Network [OSTI]

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

Victoria, University of

251

A Dynamic Supply-Demand Model for Electricity Prices Manuela Buzoianu  

E-Print Network [OSTI]

A Dynamic Supply-Demand Model for Electricity Prices Manuela Buzoianu , Anthony E. Brockwell, and Duane J. Seppi Abstract We introduce a new model for electricity prices, based on the principle in a study of Californian wholesale electricity prices over a three-year period including the crisis period

252

Affinely-rigid body and oscillatory dynamical models on GL(2,R)  

E-Print Network [OSTI]

Discussed is a model of the two-dimensional affinely-rigid body with the double dynamical isotropy. We investigate the systems with potential energies for which the variables can be separated. The special stress is laid on the model of the harmonic oscillator potential and certain anharmonic alternatives. Some explicit solutions are found on the classical, quasiclassical (Bohr-Sommerfeld) and quantum level.

Agnieszka Martens; Jan J. S?awianowski

2010-11-23T23:59:59.000Z

253

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

E-Print Network [OSTI]

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics Hong Gun Sung½ and Stephan T. Grilli¾ ½ Korea Ocean Research and Development Institute, Daejeon model fully nonlinear free surface waves caused by a translating dis- turbance made of a pressure patch

Grilli, Stéphan T.

254

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

E-Print Network [OSTI]

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

255

Dynamic Modeling by Usage Data for Personalization Systems Saeed R. Aghabozorgi1  

E-Print Network [OSTI]

Dynamic Modeling by Usage Data for Personalization Systems Saeed R. Aghabozorgi1 , Teh Ying Wah2 Department of Information Science, Faculty of Computer Science and Information Technology, University mining algorithms to personalize web sites' usage data. This paper proposes an off-line model based web

Hammerton, James

256

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

E-Print Network [OSTI]

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

257

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

E-Print Network [OSTI]

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

Gray, Wayne

258

A climate model intercomparison at the dynamics level Karsten Steinhaeuser Anastasios A. Tsonis  

E-Print Network [OSTI]

A climate model intercomparison at the dynamics level Karsten Steinhaeuser · Anastasios A. Tsonis-Verlag Berlin Heidelberg 2013 Abstract Until now, climate model intercomparison has focused primarily on annual they generate, we have adopted a new approach based on climate networks. We have considered 28 pre

Minnesota, University of

259

A climate model intercomparison at the dynamics level Karsten Steinhaeuser Anastasios A. Tsonis  

E-Print Network [OSTI]

A climate model intercomparison at the dynamics level Karsten Steinhaeuser · Anastasios A. Tsonis Until now, climate model intercomparison has focused primarily on annual and global averages of various adopted a new approach based on climate networks. We have considered 28 pre-industrial control runs

Minnesota, University of

260

A Fiber Tracking Method for Building Patient Specific Dynamic Musculoskeletal Models from  

E-Print Network [OSTI]

A Fiber Tracking Method for Building Patient Specific Dynamic Musculoskeletal Models from Diffusion tracking algorithm based on an energy minimizing active curve that is well suited for building these strand and FEM models are complex to construct and time intensive to simulate. Recently a new simulation

Gilles, Benjamin

Note: This page contains sample records for the topic "dynamics model redyn" 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

Modeling of quasistatic and dynamic load responses of filled viscoelastic materials  

E-Print Network [OSTI]

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

262

Simulation of aerosol dynamics: a comparative review of mathematical models  

SciTech Connect (OSTI)

Three modeling approaches used are based-continuous, discrete (sectional), and parameterized representations of the aerosol size distribution. Simulations of coagulation and condensation are performed with the three models for clear, hazy, and urban atmospheric conditions. Relative accuracies and computational costs are compared. Reference for the comparison is the continuous approach. The results of the study provide useful information for the selection of an aerosol model, depending on the accuracy requirements and computational constraints associated with a specific application.

Seigneur, C.; Hudischewskyj, A.B.; Seinfeld, J.H.; Whitby, K.T.; Whitby, E.R.

1986-01-01T23:59:59.000Z

263

Dynamic Conditional Correlation - A Simple Class of Multivariate GARCH Models  

E-Print Network [OSTI]

Multivariate Simultaneous GARCH," Econometric Theory 11,and Joseph Mezrich, (1996) "GARCH for Groups," Risk August,SIMPLE CLASS OF MULTIVARIATE GARCH MODELS BY ROBERT F. ENGLE

Engle, Robert F

2000-01-01T23:59:59.000Z

264

advanced dynamic models: Topics by E-print Network  

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

. . . . 18 3.4.1 Heat Exchanger - Code description . . . . . . . . . . . . . . . 18 3.4.2 Simulation ResultsADVANCED POWER PLANT MODELING WITH APPLICATIONS TO THE ADVANCED BOILING...

265

Dynamic Models for Wind Turbines and Wind Power Plants  

SciTech Connect (OSTI)

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

Singh, M.; Santoso, S.

2011-10-01T23:59:59.000Z

266

Representation of Dormant and Active Microbial Dynamics for Ecosystem Modeling  

SciTech Connect (OSTI)

Dormancy is an essential strategy for microorganisms to cope with environmental stress. However, global ecosystem models typically ignore microbial dormancy, resulting in notable model uncertainties. To facilitate the consideration of dormancy in these large-scale models, we propose a new microbial physiology component that works for a wide range of substrate availabilities. This new model is based on microbial physiological states and the major parameters are the maximum specific growth and maintenance rates of active microbes and the ratio of dormant to active maintenance rates. A major improvement of our model over extant models is that it can explain the low active microbial fractions commonly observed in undisturbed soils. Our new model shows that the exponentially-increasing respiration from substrate-induced respiration experiments can only be used to determine the maximum specific growth rate and initial active microbial biomass, while the respiration data representing both exponentially-increasing and non-exponentially-increasing phases can robustly determine a range of key parameters including the initial total live biomass, initial active fraction, the maximum specific growth and maintenance rates, and the half-saturation constant. Our new model can be incorporated into existing ecosystem models to account for dormancy in microbially-driven processes and to provide improved estimates of microbial activities.

Wang, Gangsheng [ORNL; Mayes, Melanie [ORNL; Gu, Lianhong [ORNL; Schadt, Christopher Warren [ORNL

2014-01-01T23:59:59.000Z

267

Relativistic Dynamical Collapse Model for a Scalar Field  

E-Print Network [OSTI]

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

Philip Pearle

2014-04-26T23:59:59.000Z

268

Sandia National Laboratories: structural-dynamics modeling capability  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbineredox-activeNational Solar Thermalssls exhibitstructural-dynamics

269

Dynamical Models Explaining Social Balance and Evolution of Cooperation  

E-Print Network [OSTI]

factions. Examples of such a split abound: revolutionaries versus an old regime, Republicans versus such factions emerge. An earlier model could explain the formation of such factions if reputations were assumed to split into two factions. In addition, the alternative model may lead to cooperation when faced

De Leenheer, Patrick

270

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

SciTech Connect (OSTI)

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

Deng, Yueying; Kruger, Albert A.

2013-12-16T23:59:59.000Z

271

Modeling Dynamic Receptive Field Changes in Primary Visual Cortex Using Inhibitory Learning  

E-Print Network [OSTI]

The position, size, and shape of the visual receptive field (RF) of some primary visual cortical neurons change dynamically, in response to artificial scotoma conditioning in cats (Pettet & Gilbert, 1992) and to retinal lesions in cats and monkeys (DarianSmith & Gilbert, 1995). The "EXIN" learning rules (Marshall, 1995) are used to model dynamic RF changes. The EXIN model is compared with an adaptation model (Xing & Gerstein, 1994) and the LISSOM model (Sirosh & Miikkulainen, 1994; Sirosh et al., 1996). To emphasize the role of the lateral inhibitory learning rules, the EXIN and the LISSOM simulations were done with only lateral inhibitory learning. During scotoma conditioning, the EXIN model without feedforward learning produces centrifugal expansion of RFs initially inside the scotoma region, accompanied by increased responsiveness, without changes in spontaneous activation. The EXIN model without feedforward learning is more consistent with the neurophysiological data than are the a...

1997-01-01T23:59:59.000Z

272

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

E-Print Network [OSTI]

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

Athanasios Chatzistavrakidis

2014-07-25T23:59:59.000Z

273

Advanced Modeling of Renewable Energy Market Dynamics: May 2006  

SciTech Connect (OSTI)

This report documents a year-long academic project, presenting selected techniques for analysis of market growth, penetration, and forecasting applicable to renewable energy technologies. Existing mathematical models were modified to incorporate the effects of fiscal policies and were evaluated using available data. The modifications were made based on research and classification of current mathematical models used for predicting market penetration. An analysis of the results was carried out, based on available data. MATLAB versions of existing and new models were developed for research and policy analysis.

Evans, M.; Little, R.; Lloyd, K.; Malikov, G.; Passolt, G.; Arent, D.; Swezey, B.; Mosey, G.

2007-08-01T23:59:59.000Z

274

Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint  

SciTech Connect (OSTI)

This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts was also performed. Key cost components included the material and construction costs of the buoy; material and installation costs of the tethers, mooring lines, and anchor technologies; costs of transporting and installing the system at the chosen site; and the cost of mounting the wind turbine to the platform. The two systems were evaluated based on their static and dynamic performance and the total system installed cost. Both systems demonstrated acceptable motions, and have estimated costs of $1.4-$1.8 million, not including the cost of the wind turbine, the power electronics, or the electrical transmission.

Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.

2006-03-01T23:59:59.000Z

275

Ris-R-1400(EN) Dynamic wind turbine models in power  

E-Print Network [OSTI]

Risø-R-1400(EN) Dynamic wind turbine models in power system simulation tool DIgSILENT Anca D December 2003 #12;#12;Contents Preface 5 1 Introduction 6 2 Wind turbine modelling in DIgSILENT 7 2.1 Power converters 14 2.2.3 Transformer 16 2.3 DSL models of wind turbine in DIgSILENT 18 2.3.1 Initialisation issues

276

Dynamics of holographic vacuum energy in the DGP model  

E-Print Network [OSTI]

We consider the evolution of the vacuum energy in the DGP model according to the holographic principle under the assumption that the relation linking the IR and UV cut-offs still holds in this scenario. The model is studied when the IR cut-off is chosen to be the Hubble scale $H^{-1}$, the particle horizon $R_{\\rm ph}$ and the future event horizon $R_{\\rm eh}$, respectively. And the two branches of the DGP model are also taken into account. Through numerical analysis, we find that in the cases of $H^{-1}$ in the (+) branch and $R_{\\rm eh}$ in both branches, the vacuum energy can play the role of dark energy. Moreover, when considering the combination of the vacuum energy and the 5D gravity effect in both branches, the equation of state of the effective dark energy may cross -1, which may lead to the Big Rip singularity. Besides, we constrain the model with the Type Ia supernovae and baryon oscillation data and find that our model is consistent with current data within $1\\sigma$, and that the observations prefer either a pure holographic dark energy or a pure DGP model

Xing Wu; Rong-Gen Cai; Zong-Hong Zhu

2007-12-21T23:59:59.000Z

277

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

E-Print Network [OSTI]

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

Tsiotras, Panagiotis

278

Interaction of waves and currents with kelp forests (Macrocystis pyrifera): Insights from a dynamically scaled laboratory model  

E-Print Network [OSTI]

a dynamically matched 1/25-scale physical model in a laboratory flume. In experiments with kelp mimics, waves a dynamically scaled laboratory model Johanna H. Rosman,a,* Mark W. Denny,b Robert B. Zeller,c Stephen G between model kelp and water under waves increased wake generation of turbulence, resulting in turbulent

Denny, Mark

279

19th. AIAA-CEAS Aeroacoutics Conference, May 28th 2013, Berlin Dynamic Modeling and Numerical Simulation of  

E-Print Network [OSTI]

19th. AIAA-CEAS Aeroacoutics Conference, May 28th 2013, Berlin Dynamic Modeling and Numerical was presented in this paper. By this control-oriented model, transient dynamic process of multi-physics coupling problem in a progressive wave tube could be approximately studied. The proposed model is verified

Huang, Xun

280

The dynamics of a low-order coupled ocean-atmosphere model  

E-Print Network [OSTI]

A system of five ordinary differential equations is studied which combines the Lorenz-84 model for the atmosphere and a box model for the ocean. The behaviour of this system is studied as a function of the coupling parameters. For most parameter values, the dynamics of the atmosphere model is dominant. For a range of parameter values, competing attractors exist. The Kaplan-Yorke dimension and the correlation dimension of the chaotic attractor are numerically calculated and compared to the values found in the uncoupled Lorenz model. In the transition from periodic behaviour to chaos intermittency is observed. The intermittent behaviour occurs near a Neimark-Sacker bifurcation at which a periodic solution loses its stability. The length of the periodic intervals is governed by the time scale of the ocean component. Thus, in this regime the ocean model has a considerable influence on the dynamics of the coupled system.

L. van Veen; F. Verhulst; T. Opsteegh

1998-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Dynamic models of residential segregation: brief review, analytical resolution and study of the introduction of coordination  

E-Print Network [OSTI]

In his 1971's Dynamic Models of Segregation paper, the economist Thomas C. Schelling showed that a small preference for one's neighbors to be of the same color could lead to total segregation, even if total segregation does not correspond to individual preferences and to a residential configuration maximizing the collective utility. The present work is aimed at deepening the understanding of the properties of dynamic models of segregation based on Schelling's hypotheses. Its main contributions are (i) to offer a comprehensive and up-to-date review of this family of models; (ii) to provide an analytical solution to the most general form of this model under rather general assumptions; to the best of our knowledge, such a solution did not exist so far; (iii) to analyse the effect of two devices aimed at decreasing segregation in such a model.

Grauwin, S; Jensen, P

2009-01-01T23:59:59.000Z

282

Using Simulations and kinetic network models to reveal the dynamics and functions of Riboswitches  

E-Print Network [OSTI]

Riboswitches, RNA elements found in the untranslated region, regulate gene expression by binding to target metaboloites with exquisite specificity. Binding of metabolites to the conserved aptamer domain allosterically alters the conformation in the downstream expression platform. The fate of gene expression is determined by the changes in the downstream RNA sequence. As the metabolite-dependent cotranscriptional folding and unfolding dynamics of riboswitches is the key determinant of gene expression, it is important to investigate both the thermodynamics and kinetics of riboswitches both in the presence and absence of metabolite. Single molecule force experiments that decipher the free energy landscape of riboswitches from their mechanical responses, theoretical and computational studies have recently shed light on the distinct mechanism of folding dynamics in different classes of riboswitches. Here we first discuss the dynamics of water around riboswitch, highlighting that water dynamics can enhance the fluctuation of nucleic acid structure. To go beyond native state fluctuations we used the Self-Organized Polymer (SOP) model to predict the dynamics of add adenine riboswitch under mechanical forces. In addition to quantitatively predicting the folding landscape of add-riboswitch our simulations also explain the difference in the dynamics between pbuE adenine- and add adenine-riboswitches. In order to probe the function {\\it in vivo} we use the folding landscape to propose a system level kinetic network model to quantitatively predict how gene expression is regulated for riboswitches that are under kinetic control.

Jong-Chin Lin; Jeseong Yoon; Changbong Hyeon; D. Thirumalai

2014-10-02T23:59:59.000Z

283

A Predator-Prey Model with Disease Dynamics Chris Flake  

E-Print Network [OSTI]

a diseased fish population and their predators. Analysis of the system is performed to determine among the Tilapia fish of the Salton Sea and their predator, the pelican. This model is of interest deaths not only among the fish themselves, but also in the pelican population. Studies have indicated

Logan, David

284

DYNAMIC PHASORS IN MODELING, ANALYSIS AND CONTROL OF ENERGY  

E-Print Network [OSTI]

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

Stankoviæ, Aleksandar

285

Modelling the dynamical evolution of the Bootes dwarf spheroidal galaxy  

E-Print Network [OSTI]

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

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

2008-01-17T23:59:59.000Z

286

Modeling Climate Dynamically James Walsh and Richard McGehee  

E-Print Network [OSTI]

to tropical latitudes, leaving a narrow strip of open ocean water about the equator? Can mathematical models and present day evidence. Global climate is determined by the radiation balance of the planet. The Earth warms through the absorption of incoming solar radiation (or insolation). Due to the shortwave nature

Wilmer, Elizabeth

287

Silva et al. Modelling cyanobacteria dynamics in urban lakes  

E-Print Network [OSTI]

watershed hydrologic modelling and high frequency data collection Talita SILVA*, Brigitte VINÃ?ON several essential functions for the cities such as storing rainwater and providing recreation spaces with high-frequency data collected in Lake Enghien. In the second part, we propose a methodology to connect

Paris-Sud XI, Université de

288

physics/0512181 Modelling dynamics of samples exposed to  

E-Print Network [OSTI]

not only the sample but also the optical elements of the FEL beamline. Radiation damage by photons from December 2005 Abstract: We apply Boltzmann equations for modelling the radiation damage in samples. Rapid progress of radiation damage in these samples prevents an accurate determination

289

Equilibrium model with default and insider's dynamic information Luciano Campi  

E-Print Network [OSTI]

Danilova§ August 3, 2011 Abstract We consider an equilibrium model `a la Kyle-Back for a defaultable claim, London School of Economics, u.cetin@lse.ac.uk. § Department of Mathematics, London School of Economics, a.danilova

Paris-Sud XI, Université de

290

Lurking Pathway Prediction And Pathway ODE Model Dynamic Analysis  

E-Print Network [OSTI]

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

Zhang, Rengjing

2013-11-18T23:59:59.000Z

291

Computational Fluid Dynamics Modeling of the John Day Dam Tailrace  

SciTech Connect (OSTI)

US Army Corps of Engineers - Portland District required that a two-dimensional (2D) depth-averaged and a three-dimensional (3D) free-surface numerical models to be developed and validated for the John Day tailrace. These models were used to assess potential impact of a select group of structural and operational alternatives to tailrace flows aimed at improving fish survival at John Day Dam. The 2D model was used for the initial assessment of the alternatives in conjunction with a reduced-scale physical model of the John Day Project. A finer resolution 3D model was used to more accurately model the details of flow in the stilling basin and near-project tailrace hydraulics. Three-dimensional model results were used as input to the Pacific Northwest National Laboratory particle tracking software, and particle paths and times to pass a downstream cross section were used to assess the relative differences in travel times resulting from project operations and structural scenarios for multiple total river flows. Streamlines and neutrally-buoyant particles were seeded in all turbine and spill bays with flows. For a Total River of 250 kcfs running with the Fish Passage Plan spill pattern and a spillwall, the mean residence times for all particles were little changed; however the tails of the distribution were truncated for both spillway and powerhouse release points, and, for the powerhouse releases, reduced the residence time for 75% of the particles to pass a downstream cross section from 45.5 minutes to 41.3 minutes. For a total river of 125 kcfs configured with the operations from the Fish Passage Plan for the temporary spillway weirs and for a proposed spillwall, the neutrally-buoyant particle tracking data showed that the river with a spillwall in place had the overall mean residence time increase; however, the residence time for 75% of the powerhouse-released particles to pass a downstream cross section was reduced from 102.4 min to 89 minutes.

Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C.; Serkowski, John A.

2010-07-08T23:59:59.000Z

292

An overview of APECOSM, a spatialized mass balanced ``Apex Predators ECOSystem Model" to study physiologically structured tuna population dynamics  

E-Print Network [OSTI]

physiologically structured tuna population dynamics in their ecosystem Olivier Maury * IRD (Institut de Recherche by the organisms are modelled according to the DEB (dynamic energy budget) theory (Kooijmann, 2000) and the size-structured- mental variability and fishing on the structure and dynamics of pe- lagic ecosystems. APECOSM uses a size

Hawai'i at Manoa, University of

293

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

E-Print Network [OSTI]

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

Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

2014-12-15T23:59:59.000Z

294

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

E-Print Network [OSTI]

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

Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

2015-02-18T23:59:59.000Z

295

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

E-Print Network [OSTI]

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

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

2014-07-15T23:59:59.000Z

296

Modeling ramp compression experiments using large-scale molecular dynamics simulation.  

SciTech Connect (OSTI)

Molecular dynamics simulation (MD) is an invaluable tool for studying problems sensitive to atomscale physics such as structural transitions, discontinuous interfaces, non-equilibrium dynamics, and elastic-plastic deformation. In order to apply this method to modeling of ramp-compression experiments, several challenges must be overcome: accuracy of interatomic potentials, length- and time-scales, and extraction of continuum quantities. We have completed a 3 year LDRD project with the goal of developing molecular dynamics simulation capabilities for modeling the response of materials to ramp compression. The techniques we have developed fall in to three categories (i) molecular dynamics methods (ii) interatomic potentials (iii) calculation of continuum variables. Highlights include the development of an accurate interatomic potential describing shock-melting of Beryllium, a scaling technique for modeling slow ramp compression experiments using fast ramp MD simulations, and a technique for extracting plastic strain from MD simulations. All of these methods have been implemented in Sandia's LAMMPS MD code, ensuring their widespread availability to dynamic materials research at Sandia and elsewhere.

Mattsson, Thomas Kjell Rene; Desjarlais, Michael Paul; Grest, Gary Stephen; Templeton, Jeremy Alan; Thompson, Aidan Patrick; Jones, Reese E.; Zimmerman, Jonathan A.; Baskes, Michael I. (University of California, San Diego); Winey, J. Michael (Washington State University); Gupta, Yogendra Mohan (Washington State University); Lane, J. Matthew D.; Ditmire, Todd (University of Texas at Austin); Quevedo, Hernan J. (University of Texas at Austin)

2011-10-01T23:59:59.000Z

297

Modelling the Structure and Dynamics of Science Using Books  

E-Print Network [OSTI]

Scientific research is a major driving force in a knowledge based economy. Income, health and wellbeing depend on scientific progress. The better we understand the inner workings of the scientific enterprise, the better we can prompt, manage, steer, and utilize scientific progress. Diverse indicators and approaches exist to evaluate and monitor research activities, from calculating the reputation of a researcher, institution, or country to analyzing and visualizing global brain circulation. However, there are very few predictive models of science that are used by key decision makers in academia, industry, or government interested to improve the quality and impact of scholarly efforts. We present a novel 'bibliographic bibliometric' analysis which we apply to a large collection of books relevant for the modelling of science. We explain the data collection together with the results of the data analyses and visualizations. In the final section we discuss how the analysis of books that describe different modellin...

Ginda, Michael; Borner, Katy

2015-01-01T23:59:59.000Z

298

Development of a Dynamic DOE Calibration Model | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent CompanyaUSAMP AMDHeavy Duty TrucksDevelopment

299

Detonating Failed Deflagration Model of Thermonuclear Supernovae I. Explosion Dynamics  

E-Print Network [OSTI]

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

Tomasz Plewa

2006-11-24T23:59:59.000Z

300

Lattice Boltzmann model for collisionless electrostatic drift wave turbulence obeying Charney-Hasegawa-Mima dynamics  

E-Print Network [OSTI]

A lattice Boltzmann method (LBM) approach to the Charney-Hasegawa-Mima (CHM) model for adiabatic drift wave turbulence in magnetised plasmas, is implemented. The CHM-LBM model contains a barotropic equation of state for the potential, a force term including a cross-product analogous to the Coriolis force in quasigeostrophic models, and a density gradient source term. Expansion of the resulting lattice Boltzmann model equations leads to cold-ion fluid continuity and momentum equations, which resemble CHM dynamics under drift ordering. The resulting numerical solutions of standard test cases (monopole propagation, stable drift modes and decaying turbulence) are compared to results obtained by a conventional finite difference scheme that directly discretizes the CHM equation. The LB scheme resembles characteristic CHM dynamics apart from an additional shear in the density gradient direction. The occuring shear reduces with the drift ratio and is ascribed to the compressible limit of the underlying LBM.

Held, M

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Adaptive Model Predictive Control of the Hybrid Dynamics of a Fuel Cell System.  

E-Print Network [OSTI]

Adaptive Model Predictive Control of the Hybrid Dynamics of a Fuel Cell System. M. Fiacchini, T operation of a fuel cell system is presented. The aim of the control design is to guarantee that the oxygen control to a fuel cell plant is presented. The fuel cell, located in the laboratory of the Department

Paris-Sud XI, Université de

302

DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

303

A dynamic organic soil biogeochemical model for simulating the effects of wildfire on soil environmental  

E-Print Network [OSTI]

of surface energy balance [Liu et al., 2005], soil thermal and hydrological regimes [MacKay, 1995; Burn, 1998A dynamic organic soil biogeochemical model for simulating the effects of wildfire on soil not comprehensively considered how interactions among fire disturbance, soil environmental conditions

Wagner, Diane

304

Soft-ratchet modeling of slow dynamics in the nonlinear resonant response of sedimentary  

E-Print Network [OSTI]

Soft-ratchet modeling of slow dynamics in the nonlinear resonant response of sedimentary rocks of Physics 0-7354-0330-9/06/$23.00 CREDIT LINE (BELOW) TO BE INSERTED ONLY ON THE FIRST PAGE OF THE #12;SOFT-RATCHET

305

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

E-Print Network [OSTI]

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

Chen, Qingyan "Yan"

306

A Note on Dynamic Data Driven Wildfire Modeling , L.P. Franca1  

E-Print Network [OSTI]

of the interactions of fire, weather, and fuel, driven by remote sensing data of fire location and land surfaceA Note on Dynamic Data Driven Wildfire Modeling J. Mandel1 , M. Chen1 , L.P. Franca1 , C. Johns1 of Colorado Denver, Denver, CO 80217-3364, USA 2 National Center for Atmospheric Research, Boulder, CO 80307

Douglas, Craig C.

307

Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds  

E-Print Network [OSTI]

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

308

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

E-Print Network [OSTI]

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

Skogestad, Sigurd

309

A model for vendor selection and dynamic evaluation Raffele Iannone1  

E-Print Network [OSTI]

A model for vendor selection and dynamic evaluation Raffele Iannone1 , Salvatore Miranda1 , Stefano with the monitoring and the continuous analysis of the vendor performances. The vendor evaluation process is realised and obtainable benefits. Keywords: Vendor Evaluation, Vendor Selection, AHP, Supply Management 1 Introduction

Paris-Sud XI, Université de

310

Modelling of power plant dynamics and uncertainties for robust control synthesis *  

E-Print Network [OSTI]

-Kuo Weng, Asok Ray and Xiaowen Dai Mechanical Engineering Department, The Pennsylvania State University systems synthesis. In lieu of the actual plant data, mathematical models of computational fluid dynamics of Mechanical Engineering, The Pennsylvania State University, 137 Reber Building, University Park, PA 16802

Ray, Asok

311

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

E-Print Network [OSTI]

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

Bjørnstad, Ottar Nordal

312

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

E-Print Network [OSTI]

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

Sikdar, Biplab

313

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

E-Print Network [OSTI]

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

Boyer, Edmond

314

UNCORRECTED 2 Models of natural and human dynamics in forest landscapes  

E-Print Network [OSTI]

protected areas, though they differ in the specifics of vegetation and land 23 use. In the Texas sitesUNCORRECTED PROOF 1 2 Models of natural and human dynamics in forest landscapes: 3 Cross natural and human systems across sites and cultures through a process of simplification and 17 abstraction

Monticino, Michael

315

A Combined Molecular Dynamics and Diffusion Model of Single Proton Conduction through Gramicidin  

E-Print Network [OSTI]

A Combined Molecular Dynamics and Diffusion Model of Single Proton Conduction through Gramicidin through the gramicidin pore is described by a potential of mean force and diffusion coefficient obtained in the hydrogen bonding structure of pore waters without an excess proton. Proton entrance and exit were

Schumaker, Mark

316

Energy dynamics and modeled evapotranspiration from a wet tropical forest in Costa Rica  

E-Print Network [OSTI]

Energy dynamics and modeled evapotranspiration from a wet tropical forest in Costa Rica H). #12;1. Introduction The energy balance of tropical forests is complex due to feedback mechanisms among.W. Loeschera, *, H.L. Gholza,b , J.M. Jacobsc , S.F. Oberbauerd,e a School of Forest Resources and Conservation

317

Bayesian Emulation of Complex Multi-Output and Dynamic Computer Models  

E-Print Network [OSTI]

Bayesian Emulation of Complex Multi-Output and Dynamic Computer Models Stefano Conti Anthony O the case). In particular, standard Monte Carlo-based methods of sensitivity analysis (extensively reviewed'Hagan, 2002), offering substantial efficiency gains over standard Monte Carlo-based meth- ods. These authors

Oakley, Jeremy

318

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

E-Print Network [OSTI]

FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY Prabir Daripa developed flows in enhanced oil recovery (EOR). In a recent exhaustive study [Transport in Porous Media, 93 fluid flows that occur in porous media during tertiary dis- placement process of chemical enhanced oil

Daripa, Prabir

319

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS  

E-Print Network [OSTI]

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

Phani, A. Srikantha

320

A COMPARISON BETWEEN TWO SIMPLIFIED DYNAMICAL MODELS FOR THE HUMAN GAIT  

E-Print Network [OSTI]

A COMPARISON BETWEEN TWO SIMPLIFIED DYNAMICAL MODELS FOR THE HUMAN GAIT A.Ortega 1 , F.Montoya 1 and J.Finat 2 , MoBiVA Group. 1 ETS Ing. Industrial, Paseo del Cauce, Univ. Valladolid, 47011 Valladolid to a passive approach to maintain the upright position and locomotion with a view to their applications

Llanos, Diego R.

Note: This page contains sample records for the topic "dynamics model redyn" 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

CT-PET Landmark-based Lung Registration Using a Dynamic Breathing Model S. Chambon1  

E-Print Network [OSTI]

CT-PET Landmark-based Lung Registration Using a Dynamic Breathing Model S. Chambon1 , A. Moreno1-based registration of CT (at two different instants of the breathing cycle, intermediate expirations) and PET images in order to simulate the instant in the breathing cycle most similar to the PET image and guarantee

Paris-Sud XI, Université de

322

Ecological Modelling 180 (2004) 135151 Simulating forest fuel and fire risk dynamics across  

E-Print Network [OSTI]

fuel module tracks fine fuel, coarse fuel and live fuel for each cell on a landscape. Fine fuel age (the oldest age cohorts) in combination with disturbance history. Live fuels, also called canopyEcological Modelling 180 (2004) 135­151 Simulating forest fuel and fire risk dynamics across

He, Hong S.

323

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

E-Print Network [OSTI]

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

Xin, Jack

324

Modeling particle formation during low-pressure silane oxidation: Detailed chemical kinetics and aerosol dynamics  

E-Print Network [OSTI]

that the generation of SiOHx species from fast gas- phase reactions can significantly degrade film quality. Based conservation equations and a moment-type aerosol dynamics model were formulated for a batch reactor undergoing to impurity diffusion.1 During LPCVD film deposition rates are limited by the gas-phase nucleation

Zachariah, Michael R.

325

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

E-Print Network [OSTI]

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

Central Florida, University of

326

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

E-Print Network [OSTI]

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

Van Den Eijnden, Eric

327

Coupled Damage and Plasticity Modelling in Transient Dynamic Analysis of Concrete  

E-Print Network [OSTI]

Coupled Damage and Plasticity Modelling in Transient Dynamic Analysis of Concrete F. Gatuingt Abstract In a concrete structure subjected to an explosion, for example a concrete slab, the material on the same concrete. Computations of split Hopkinson tests on confined concrete, a tensile test with scabbing

328

Cooling energy demand evaluation by means of regression models obtained from dynamic simulations  

E-Print Network [OSTI]

Cooling energy demand evaluation by means of regression models obtained from dynamic simulations Ph, Université Lyon1, FRANCE ABSTRACT The forecast of the energy heating/cooling demand would be a good indicator between simple and complex methods of evaluating the cooling energy demand we have proposed to use energy

Paris-Sud XI, Université de

329

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

E-Print Network [OSTI]

/deposition processes when a layer of particles is flowing over a static layer or near the destabilization and arrestA simplified model of thin layer static/flowing dynamics for granular materials with yield, 75005 Paris, France, 4 ANGE team, INRIA, CETMEF, Lab. J.-L. Lions, Paris, France Abstract We introduce

Paris-Sud XI, Université de

330

Building Dynamic Models of Service Compositions With Simulation of Provision Resources  

E-Print Network [OSTI]

Building Dynamic Models of Service Compositions With Simulation of Provision Resources Dragan of service compositions depends both on the composition structure, and on planning and management of compu- tational resources necessary for provision. Resource constraints on the service provider side have impact

Politécnica de Madrid, Universidad

331

Modeling the dynamics of human hair cycles by a follicular automaton  

E-Print Network [OSTI]

Modeling the dynamics of human hair cycles by a follicular automaton J. Halloy*, B. A. Bernard , G University of Brussels, Brussels, Belgium, May 15, 2000 (received for review December 23, 1999) The hair correspond, respectively, to hair growth, arrest, shedding, and absence before a new anagen phase

Goldbeter, Albert

332

Dynamical Coupled-Channel Model of Meson Production Reactions in the Nucleon Resonance Region  

SciTech Connect (OSTI)

A dynamical coupled-channel model is presented for investigating the nucleon resonances (N*) in the meson production reactions induced by pions and photons. Our objective is to extract the N* parameters and to investigate the meson production reaction mechanisms for mapping out the quark-gluon substructure of N* from the data. The model is based on an energy-independent Hamiltonian which is derived from a set of Lagrangians by using a unitary transformation method.

T.-S. H. Lee; A. Matsuyama; T. Sato

2006-11-15T23:59:59.000Z

333

Dynamical Systems analysis of an interacting dark energy model in the Brane Scenario  

E-Print Network [OSTI]

In this paper, we investigate the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here we consider an homogeneous and isotropic Friedmann-Robertson-Walker (FRW) brane model and the evolution equations are reduced to an autonomous system by suitable transformation of variables. The nature of critical points are analyzed by evaluating the eigenvalues of linearized Jacobi matrix. Finally, the classical stability of the model is also studied.

Biswas, Sujay Kr

2015-01-01T23:59:59.000Z

334

Stochastic Dynamic Demand Inventory Models with Explicit Transportation Costs and Decisions  

E-Print Network [OSTI]

is the policy where several small loads will be dispatched as a single, combined load. From an inventory-modeling perspec- tive, the integrated inventory-transportation problems add dispatch quantities as decision variables to the stochastic dynamic inventory...): The vendor makes the inventory replen- ishment decisions on how much to order from the outside supplier. 2. Pure Outbound Transportation Models (PO): The collection depot makes the delivery schedules of order dispatches to the buyer(s). 3. Integrated...

Zhang, Liqing

2011-07-01T23:59:59.000Z

335

Experimental results and modeling of a dynamic hohlraum on SATURN  

SciTech Connect (OSTI)

Experiments were performed at SATURN, a high current z-pinch, to explore the feasibility of creating a hohlraum by imploding a tungsten wire array onto a low-density foam. Emission measurements in the 200--280 eV energy band were consistent with a 110--135 eV Planckian before the target shock heated, or stagnated, on-axis. Peak pinch radiation temperatures of nominally 160 eV were obtained. Measured early time x-ray emission histories and temperature estimates agree well with modeled performance in the 200--280 eV band using a 2D radiation magneto-hydrodynamics code. However, significant differences are observed in comparisons of the x-ray images and 2D simulations.

Derzon, M.S.; Allshouse, G.O.; Deeney, C.; Leeper, R.J.; Nash, T.J. [Sandia National Labs., Albuquerque, NM (United States); Matuska, W.; Peterson, D.L. [Los Alamos National Lab., NM (United States); MacFarlane, J.J. [Univ. of Wisconsin, Madison, WI (United States); Ryutov, D.D. [Lawrence Livermore National Lab., CA (United States)

1998-06-01T23:59:59.000Z

336

Membrane Fuzzy Sphere Dynamics in Plane-Wave Matrix Model  

E-Print Network [OSTI]

In plane-wave matrix model, the membrane fuzzy sphere extended in the SO(3) symmetric space is allowed to have periodic motion on a sub-plane in the SO(6) symmetric space. We consider a background configuration composed of two such fuzzy spheres moving on the same sub-plane and the one-loop quantum corrections to it. The one-loop effective action describing the fuzzy sphere interaction is computed up to the sub-leading order in the limit that the mean distance $r$ between two fuzzy spheres is very large. We show that the leading order interaction is of the 1/r^7 type and thus the membrane fuzzy spheres interpreted as giant gravitons really behave as gravitons.

Hyeonjoon Shin; Kentaroh Yoshida

2004-09-03T23:59:59.000Z

337

Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model  

E-Print Network [OSTI]

with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

Schuh, Harald

338

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai, Dongmei Chen, Tess J. Moon  

E-Print Network [OSTI]

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai to improve the performance of a PEM fuel cell Simulation Results Advanced Power Systems and Controls (GDL) to reduce water saturation · Model water transport in PEM fuel cell Contribution: · Dynamic

Ben-Yakar, Adela

339

Technical Review of the CENWP Computational Fluid Dynamics Model of the John Day Dam Forebay  

SciTech Connect (OSTI)

The US Army Corps of Engineers Portland District (CENWP) has developed a computational fluid dynamics (CFD) model of the John Day forebay on the Columbia River to aid in the development and design of alternatives to improve juvenile salmon passage at the John Day Project. At the request of CENWP, Pacific Northwest National Laboratory (PNNL) Hydrology Group has conducted a technical review of CENWP's CFD model run in CFD solver software, STAR-CD. PNNL has extensive experience developing and applying 3D CFD models run in STAR-CD for Columbia River hydroelectric projects. The John Day forebay model developed by CENWP is adequately configured and validated. The model is ready for use simulating forebay hydraulics for structural and operational alternatives. The approach and method are sound, however CENWP has identified some improvements that need to be made for future models and for modifications to this existing model.

Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.

2010-12-01T23:59:59.000Z

340

Fundamental problems of modeling the dynamics of internal gravity waves with applications to the Arctic Basin  

E-Print Network [OSTI]

In this paper, we consider fundamental problems of the dynamics of internal gravity waves. We present analytical and numerical algorithms for calculating the wave fields for a set of values of the parameters, as observed in the ocean. We show that our mathematical models can describe the wave dynamics of the Arctic Basin, taking into account the actual physical characteristics of sea water, topography of its floor, etc. The numerical and analytical results show that the internal gravity waves have a significant effect on underwater sea objects in the Arctic Basin.

Vitaly V. Bulatov; Yuriy V. Vladimirov

2012-06-26T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Quantum Dynamical Model for Wave Function Reduction in Classical and Macroscopic Limits  

E-Print Network [OSTI]

In this papper, a quantum dynamical model describing the quantum measurement process is presented as an extensive generalization of the Coleman-Hepp model. In both the classical limit with very large quantum number and macroscopic limit with very large particle number in measuring instrument, this model generally realizes the wave packet collapse in quantum measurement as a consequence of the Schrodinger time evolution in either the exactly-solvable case or the non-(exactly-)solvable case. For the latter, its quasi-adiabatic case is explicitly analysed by making use of the high-order adiabatic approximation method and then manifests the wave packet collapse as well as the exactly-solvable case. By highlighting these analysis, it is finally found that an essence of the dynamical model of wave packet collapse is the factorization of the Schrodinger evolution other than the exact solvability. So many dynamical models including the well-known ones before, which are exactly-solvable or not, can be shown only to be the concrete realizations of this factorizability

Chang-Pu Sun

1993-03-22T23:59:59.000Z

342

Simulation of aerosol dynamics: A comparative review of algorithms used in air quality models  

SciTech Connect (OSTI)

A comparative review of algorithms currently used in air quality models to simulate aerosol dynamics is presented. This review addresses coagulation, condensational growth, nucleation, and gas/particle mass transfer. Two major approaches are used in air quality models to represent the particle size distribution: (1) the sectional approach in which the size distribution is discretized into sections and particle properties are assumed to be constant over particle size sections and (2) the modal approach in which the size distribution is approximated by several modes and particle properties are assumed to be uniform in each mode. The results of this study provide useful information to select algorithms to simulate aerosol dynamics in air quality models and to improve the accuracy of existing algorithms.

Zhang, Y.; Seigneur, C.; Seinfeld, J.H.; Jacobson, M.Z.; Binkowski, F.S.

1999-01-01T23:59:59.000Z

343

Renormalization of lattice-regularized quantum gravity models II. The case of causal dynamical triangulations  

E-Print Network [OSTI]

The causal dynamical triangulations approach aims to construct a quantum theory of gravity as the continuum limit of a lattice-regularized model of dynamical geometry. A renormalization group scheme--in concert with finite size scaling analysis--is essential to this aim. Formulating and implementing such a scheme in the present context raises novel and notable conceptual and technical problems. I explored these problems, and, building on standard techniques, suggested potential solutions in the first paper of this two-part series. As an application of these solutions, I now propose a renormalization group scheme for causal dynamical triangulations. This scheme differs significantly from that studied recently by Ambjorn, Gorlich, Jurkiewicz, Kreienbuehl, and Loll.

Joshua H. Cooperman

2014-06-17T23:59:59.000Z

344

Dynamic Jiles-Atherton Model for Determining the Magnetic Power Loss at High Frequency in Permanent Magnet Machines  

E-Print Network [OSTI]

BH curves at frequencies up to several kilohertz. B. Application of the Dynamic Jiles-Atherton Model to the Magnetic Loss of a PMSM (BLDC motor) According to Guo’s review paper, empirical formulae have been derived to model the magnetic properties... of the conventional time stepped FEM [11], [26], [27] to utilize the proposed dynamic Jiles-Atherton model to estimate the magnetic power loss in a PMSM. More mathematical work needs to be done to make the dynamic Jiles-Atherton model and time stepped FEM...

Du, Ruoyang; Student Member; IEEE; Robertson, Paul

2014-12-18T23:59:59.000Z

345

Modeling, simulation, and testing of the mechanical dynamics of and RF MEMS switch.  

SciTech Connect (OSTI)

Mechanical dynamics can be a determining factor for the switching speed of radio-frequency microelectromechanical systems (RF MEMS) switches. This paper presents the simulation of the mechanical motion of a microswitch under actuation. The switch has a plate suspended by springs. When an electrostatic actuation is applied, the plate moves toward the substrate and closes the switch. Simulations are calculated via a high-fidelity finite element model that couples solid dynamics with electrostatic actuation. It incorporates non-linear coupled dynamics and accommodates fabrication variations. Experimental modal analysis gives results in the frequency domain that verifies the natural frequencies and mode shapes predicted by the model. An effective 1D model is created and used to calculate an actuation voltage waveform that minimizes switch velocity at closure. In the experiment, the switch is actuated with this actuation voltage, and the displacements of the switch at various points are measured using a laser Doppler velocimeter through a microscope. The experiments are repeated on several switches from different batches. The experimental results verify the model.

Sumali, Hartono; Epp, David S.; Massad, Jordan Elias; Dyck, Christopher William; Starr, Michael James

2005-07-01T23:59:59.000Z

346

Introduction to the application of the dynamical systems theory in the study of the dynamics of cosmological models of dark energy  

E-Print Network [OSTI]

The theory of the dynamical systems is a very complex subject which has brought several surprises in the recent past in connection with the theory of chaos and fractals. The application of the tools of the dynamical systems in cosmological settings is less known in spite of the amount of published scientific papers on this subject. In this paper a -- mostly pedagogical -- introduction to the application in cosmology of the basic tools of the dynamical systems theory is presented. It is shown that, in spite of their amazing simplicity, these allow to extract essential information on the asymptotic dynamics of a wide variety of cosmological models. The power of these tools is illustrated within the context of the so called $\\Lambda$CDM and scalar field models of dark energy. This paper is suitable for teachers, undergraduate and postgraduate students from physics and mathematics disciplines.

García-Salcedo, Ricardo; Horta-Rangel, Francisco A; Quiros, Israel; Sanchez-Guzmán, Daniel

2015-01-01T23:59:59.000Z

347

Coastal Dynamics 2013 A 3-D PHASE-AVERAGED MODEL FOR SHALLOW WATER FLOW WITH WAVES IN  

E-Print Network [OSTI]

Coastal Dynamics 2013 1915 A 3-D PHASE-AVERAGED MODEL FOR SHALLOW WATER FLOW WITH WAVES in coastal vegetated waters with short waves. The model adopts the 3-D phase-averaged shallow water flow mesh in the vertical direction. The flow model is coupled with a spectral wave deformation model called

US Army Corps of Engineers

348

Control method and system for hydraulic machines employing a dynamic joint motion model  

DOE Patents [OSTI]

A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

Danko, George (Reno, NV)

2011-11-22T23:59:59.000Z

349

Dynamic Conic Finance: Pricing and Hedging in Market Models with Transaction Costs via Dynamic Coherent Acceptability Indices  

E-Print Network [OSTI]

In this paper we present a theoretical framework for determining dynamic ask and bid prices of derivatives using the theory of dynamic coherent acceptability indices in discrete time. We prove a version of the First Fundamental Theorem of Asset Pricing using the dynamic coherent risk measures. We introduce the dynamic ask and bid prices of a derivative contract in markets with transaction costs. Based on these results, we derive a representation theorem for the dynamic bid and ask prices in terms of dynamically consistent sequence of sets of probability measures and risk-neutral measures. To illustrate our results, we compute the ask and bid prices of some path-dependent options using the dynamic Gain-Loss Ratio.

Bielecki, Tomasz R; Iyigunler, Ismail; Rodriguez, Rodrigo

2012-01-01T23:59:59.000Z

350

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

SciTech Connect (OSTI)

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

Vogler, Tracy; Lammi, Christopher James

2014-10-01T23:59:59.000Z

351

Generalized spherically symmetric gravitational model: Hamiltonian dynamics in extended phase space and BRST charge  

E-Print Network [OSTI]

We construct Hamiltonian dynamics of the generalized spherically symmetric gravitational model in extended phase space. We start from the Faddeev - Popov effective action with gauge-fixing and ghost terms, making use of gauge conditions in differential form. It enables us to introduce missing velocities into the Lagrangian and then construct a Hamiltonian function according a usual rule which is applied for systems without constraints. The main feature of Hamiltonian dynamics in extended phase space is that it can be proved to be completely equivalent to Lagrangian dynamics derived from the effective action. We find a BRST invariant form of the effective action by adding terms not affecting Lagrangian equations. After all, we construct the BRST charge according to the Noether theorem. Our algorithm differs from that by Batalin, Fradkin and Vilkovisky, but the resulting BRST charge generates correct transformations for all gravitational degrees of freedom including gauge ones. Generalized spherically symmetric model imitates the full gravitational theory much better then models with finite number of degrees of freedom, so that one can expect appropriate results in the case of the full theory.

T. P. Shestakova

2014-06-12T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

353

Advanced High-Temperature Reactor Dynamic System Model Development: April 2012 Status  

SciTech Connect (OSTI)

The Advanced High-Temperature Reactor (AHTR) is a large-output fluoride-salt-cooled high-temperature reactor (FHR). An early-phase preconceptual design of a 1500 MW(e) power plant was developed in 2011 [Refs. 1 and 2]. An updated version of this plant is shown as Fig. 1. FHRs feature low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. The AHTR is designed to be a “walk away” reactor that requires no action to prevent large off-site releases following even severe reactor accidents. This report describes the development of dynamic system models used to further the AHTR design toward that goal. These models predict system response during warmup, startup, normal operation, and limited off-normal operating conditions. Severe accidents that include a loss-of-fluid inventory are not currently modeled. The scope of the models is limited to the plant power system, including the reactor, the primary and intermediate heat transport systems, the power conversion system, and safety-related or auxiliary heat removal systems. The primary coolant system, the intermediate heat transport system and the reactor building structure surrounding them are shown in Fig. 2. These systems are modeled in the most detail because the passive interaction of the primary system with the surrounding structure and heat removal systems, and ultimately the environment, protects the reactor fuel and the vessel from damage during severe reactor transients. The reactor silo also plays an important role during system warmup. The dynamic system modeling tools predict system performance and response. The goal is to accurately predict temperatures and pressures within the primary, intermediate, and power conversion systems and to study the impacts of design changes on those responses. The models are design tools and are not intended to be used in reactor qualification. The important details to capture in the primary system relate to flows within the reactor vessel during severe events and the resulting temperature profiles (temperature and duration) for major components. Critical components include the fuel, reactor vessel, primary piping, and the primary-to-intermediate heat exchangers (P-IHXs). The major AHTR power system loops are shown in Fig. 3. The intermediate heat transfer system is a group of three pumped salt loops that transports the energy produced in the primary system to the power conversion system. Two dynamic system models are used to analyze the AHTR. A Matlab/Simulink?-based model initiated in 2011 has been updated to reflect the evolving design parameters related to the heat flows associated with the reactor vessel. The Matlab model utilizes simplified flow assumptions within the vessel and incorporates an empirical representation of the Direct Reactor Auxiliary Cooling System (DRACS). A Dymola/Modelica? model incorporates a more sophisticated representation of primary coolant flow and a physics-based representation of the three-loop DRACS thermal hydraulics. This model is not currently operating in a fully integrated mode. The Matlab model serves as a prototype and provides verification for the Dymola model, and its use will be phased out as the Dymola model nears completion. The heat exchangers in the system are sized using spreadsheet-based, steady-state calculations. The detail features of the heat exchangers are programmed into the dynamic models, and the overall dimensions are used to generate realistic plant designs. For the modeling cases where the emphasis is on understanding responses within the intermediate and primary systems, the power conversion system may be modeled as a simple boundary condition at the intermediate-to-power conversion system heat exchangers.

Qualls, A.L.; Cetiner, M.S.; Wilson, T.L., Jr.

2012-04-30T23:59:59.000Z

354

Equilibrium Response and Transient Dynamics Datasets from VEMAP: Vegetation/Ecosystem Modeling and Analysis Project  

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

Users of the VEMAP Portal can access input files of numerical data that include monthly and daily files of geographic data, soil and site files, scenario files, etc. Model results from Phase I, the Equilibrium Response datasets, are available through the NCAR anonymous FTP site at http://www.cgd.ucar.edu/vemap/vresults.html. Phase II, Transient Dynamics, include climate datasets, models results, and analysis tools. Many supplemental files are also available from the main data page at http://www.cgd.ucar.edu/vemap/datasets.html.

355

Modeling the dynamic response of pressures in a distributed helium refrigeration system  

SciTech Connect (OSTI)

A mathematical model is created of the dynamic response of pressures caused by flow inputs to an existing distributed helium refrigeration system. The dynamic system studied consists of the suction and discharge pressure headers and compressor portions of the refrigeration system used to cool the superconducting magnets of the Tevatron accelerator at the Fermi National Accelerator Laboratory. The modeling method involves identifying the system from data recorded during a series of controlled tests, with effort made to detect locational differences in pressure response around the four mile accelerator circumference. A review of the fluid mechanics associated with the system indicates linear time invariant models are suitable for the identification, particularly since the governing equations of one dimensional fluid flow are approximated by linear differential equations. An outline of the experimental design and the data acquisition system are given, followed by a detailed description of the modeling, which utilized the Matlab programming language and associated System Identification Toolbox. Two representations of the system are presented. One, a black box model, provides a multi-input, multi-output description assembled from the results of single input step function testing. This description indicates definite variation in pressure response with distance from the flow input location, and also suggests subtle differences in response with the input location itself. A second system representation is proposed which details the relation between continuous flow changes and pressure response, and provides explanation of a previously unappreciated pressure feedback internal to the system.

Brubaker, J.C.

1997-12-01T23:59:59.000Z

356

Reconstructing generalized ghost condensate model with dynamical dark energy parametrizations and observational datasets  

E-Print Network [OSTI]

Observations of high-redshift supernovae indicate that the universe is accelerating at the present stage, and we refer to the cause for this cosmic acceleration as ``dark energy''. In particular, the analysis of current data of type Ia supernovae (SNIa), cosmic large-scale structure (LSS), and the cosmic microwave background (CMB) anisotropy implies that, with some possibility, the equation-of-state parameter of dark energy may cross the cosmological-constant boundary ($w=-1$) during the recent evolution stage. The model of ``quintom'' has been proposed to describe this $w=-1$ crossing behavior for dark energy. As a single-real-scalar-field model of dark energy, the generalized ghost condensate model provides us with a successful mechanism for realizing the quintom-like behavior. In this paper, we reconstruct the generalized ghost condensate model in the light of three forms of parametrization for dynamical dark energy, with the best-fit results of up-to-date observational data.

Jingfei Zhang; Xin Zhang; Hongya Liu

2007-03-21T23:59:59.000Z

357

Incorporating daily flood control objectives into a monthly stochastic dynamic programming model for a hydroelectric complex  

SciTech Connect (OSTI)

A monthly stochastic dynamic programing model was recently developed and implemented at British Columbia (B.C.) Hydro to provide decision support for short-term energy exports and, if necessary, for flood control on the Peace River in northern British Columbia. The model established the marginal cost of supplying energy from the B.C. Hydro system, as well as a monthly operating policy for the G.M. Shrum and Peace Canyon hydroelectric plants and the Williston Lake storage reservoir. A simulation model capable of following the operating policy then determines the probability of refilling Williston Lake and possible spill rates and volumes. Reservoir inflows are input to both models in daily and monthly formats. The results indicate that flood control can be accommodated without sacrificing significant export revenue.

Druce, D.J. (British Columbia Hydro and Power Authority, Vancouver, British Columbia (Canada))

1990-01-01T23:59:59.000Z

358

System Dynamics Sustainability Model of Palm-Oil Based Biodiesel Production Chain in Indonesia  

E-Print Network [OSTI]

The nature of biodiesel production itself is complex with multisectors and multi-actors conditions, and with addition of sustainability issues from various stakeholder, created a complex challenges for developing the biodiesel industry. In order to understand of the complexity, this research developed a comprehensive sustainability model to draw the relationships and analyze the effects of government policy for stimulating biodiesel industry using the combination methods of process mapping, financial modeling, life cycle analysis (LCA) and business sustainability strategy. The model combines its output translated into a complete sustainability index of financial, social and environment. The model simulation results show that accomplishment of a sustainable biodiesel production within the target and timeframe is impossible without releasing the subsidized price of diesel fuel and further directions from the government. I Index Terms — biodiesel, system dynamics, sustainability

Akhmad Hidayatno; Aziiz Sutrisno; Yuri M. Zagloel; Widodo W. Purwanto

359

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

360

ON THE DYNAMICS OF THE SOLAR CORONA: FIRST RESULTS OBTAINED WITH A NEW 3D MHD MODEL  

E-Print Network [OSTI]

1 ON THE DYNAMICS OF THE SOLAR CORONA: FIRST RESULTS OBTAINED WITH A NEW 3D MHD MODEL J. Kleimann 1) is applied to the problem of the dynamics of the solar corona. First, we present the basic system of equations for a two- uid description of the solar wind plasma and point out possible numerical di

Grauer, Rainer

Note: This page contains sample records for the topic "dynamics model redyn" 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

Proceedings of 2009 NSF Engineering Research and Innovation Conference, Honolulu, Hawaii Grant #0838874 Dynamic Modeling of a Regenerator for the  

E-Print Network [OSTI]

#0838874 Dynamic Modeling of a Regenerator for the Control-Based Design of Free-Piston Stirling Engines-piston Stirling engines with the goal of building a working prototype. The Stirling cycle is recast as a dynamic the potential of a new, compact free-piston Stirling engine configuration using elastomeric pistons. An engine

Barth, Eric J.

362

Protein folding dynamics in lattice model with physical movement Sema Kachalo, Hsiao-Mei Lu and Jie Liang  

E-Print Network [OSTI]

Protein folding dynamics in lattice model with physical movement S¨ema Kachalo, Hsiao-Mei Lu analysis of the kinetic energy landscape. I. INTRODUCTION The dynamics of protein folding has been studied exten- sively [1, 3­5]; A remarkable empirical observation is that protein folding rates are well

Dai, Yang

363

Distributed delay model for density wave dynamics in gas lifted wells Laure Sin`egre, Nicolas Petit  

E-Print Network [OSTI]

Distributed delay model for density wave dynamics in gas lifted wells Laure Sin`egre, Nicolas Petit in the tubing D. dynamical choking is used to stabilise the density wave instability. In this paper, we propose instabilities cause production losses. One of these instabilities, referred to as the "density-wave

364

A RESTRICTED FOUR-BODY MODEL FOR THE DYNAMICS NEAR THE LAGRANGIAN POINTS OF THE SUN-JUPITER  

E-Print Network [OSTI]

A RESTRICTED FOUR-BODY MODEL FOR THE DYNAMICS NEAR THE LAGRANGIAN POINTS OF THE SUN-JUPITER SYSTEM focus on the dynamics of a small particle near the Lagrangian points of the Sun-Jupiter system. To try solution of the planar three-body problem for Sun, Jupiter and Saturn, close to the real motion

365

A spatial ecosystem and populations dynamics model (SEAPODYM) Modeling of tuna and tuna-like populations  

E-Print Network [OSTI]

Habitat modeling Movements Advection­diffusion Tuna Katsuwonus pelamis Thunnus obesus Pacific Ocean a b with two tuna species showing different biological characteristics, skipjack (Katsuwonus pelamis

Hawai'i at Manoa, University of

366

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

367

Stream ecological processes are modeled through a simple predator-prey model, which reproduces benthic algae and macro-invertebrates dynamics.  

E-Print Network [OSTI]

reproduces benthic algae and macro-invertebrates dynamics. Algae biomass = growth - death loss - predation influences on algae and macro-invertebrates dynamics will be introduced in the predator-prey model: - at increasing flow velocity high nutrient availability, algae erosion and macro-invertebrate drag

368

The use of a distributed hydrologic model to predict dynamic landslide susceptibility for a humid basin in Puerto Rico  

E-Print Network [OSTI]

This thesis describes the use of a distributed hydrology model in conjunction with a Factor of Safety (FS) algorithm to predict dynamic landslide susceptibility for a humid basin in Puerto Rico. The Mameyes basin, located ...

Kamal, Sameer A. (Sameer Ahmed)

2009-01-01T23:59:59.000Z

369

624 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 35, NO. 4, APRIL 1999 Dynamical Model of Directly Modulated  

E-Print Network [OSTI]

624 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 35, NO. 4, APRIL 1999 Dynamical Model of Directly coated at one end (z = 0) and has arbitrary reflectivity R 2 and transmissivity T 2 at the other (z = 0Lg

Sipe,J. E.

370

Utilization of Smart Materials and Predictive Modeling to Integrate Intracellular Dynamics with Cell Biomechanics and Collective Tissue Behavior  

E-Print Network [OSTI]

Utilization of Smart Materials and Predictive Modeling to Integrate Intracellular Dynamics important structures inside cells. New "smart" material will be used to trigger changes to cell movement Medical University Control of Cell Polarization by Smart Material Substrates Multiscale Imaging Multiscale

Mather, Patrick T.

371

Quantum dynamics of a four-well Bose-Hubbard model with two different tunneling rates  

SciTech Connect (OSTI)

We consider a theoretical model of a four-mode Bose-Hubbard model consisting of two pairs of wells coupled via two processes with two different rates. The model is naturally divided into two subsystems with strong intrasystem coupling and much weaker coupling between the two subsystems and has previously been introduced as a model for Josephson heat oscillations by Strzys and Anglin [Phys. Rev. A 81, 043616 (2010)]. We examine the quantum dynamics of this model for a range of different initial conditions, in terms of both the number distribution among the wells and the quantum statistics. We find that the time evolution is different to that predicted by a mean-field model and that this system exhibits a wide range of interesting behaviours. We find that the system equilibrates to a maximum entropy state and is thus a useful model for quantum thermalisation. As our model may be realized to a good approximation in the laboratory, it becomes a candidate for experimental investigation.

Chianca, C.V.; Olsen, M.K. [ARC Centre of Excellence for Quantum-Atom Optics, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072 (Australia)

2011-04-15T23:59:59.000Z

372

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.

Prusa, Joseph

2012-05-08T23:59:59.000Z

373

Evaluation of a nodal capacity restricted dynamic model for the Southwest Freeway (US-59) corridor in Houston, Texas  

E-Print Network [OSTI]

EVALUATION OF A NODAL CAPACITY RESTRICTED DYNAMIC MODEL FOR THE SOUTHWEST FREEWAY (US-59) CORRIDOR IN HOUSTON, TEXAS A Thesis by PALATHINKAL MANU ISAAC Submitted to the Office of Graduate Studies of Texas ARM University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1994 Major Subject Civil Engineering EVALUATION OF A NODAL CAPACITY RESTRICTED DYNAMIC MODEL FOR THE SOUTHWEST FREEWAY (US-59) CORRIDOR IN HOUSTON, TEXAS A Thesis...

Isaac, Palathinkal Manu

1994-01-01T23:59:59.000Z

374

Exact results for the criticality of quench dynamics in quantum Ising models  

E-Print Network [OSTI]

Based on the obtained exact results we systematically study the quench dynamics of a one-dimensional spin-1/2 transverse field Ising model with zero- and finite-temperature initial states. We focus on the magnetization of the system after a sudden change of the external field and a coherent time-evolution process. With a zero-temperature initial state, the quench magnetic susceptibility as a function of the initial field strength exhibits strongly similar scaling behaviors to those of the static magnetic susceptibility, and the quench magnetic susceptibility as a function of the final field strength shows a discontinuity at the quantum critical point. This discontinuity remains robust and always occurs at the quantum critical point even for the case of finite-temperature initial systems, which indicates a great advantage of employing quench dynamics to study quantum phase transitions.

Ying Li; M. X. Huo; Z. Song

2009-06-23T23:59:59.000Z

375

Forebay Computational Fluid Dynamics Modeling for The Dalles Dam to Support Behavior Guidance System Siting Studies  

SciTech Connect (OSTI)

Computational fluid dynamics (CFD) models were developed to support the siting and design of a behavioral guidance system (BGS) structure in The Dalles Dam (TDA) forebay on the Columbia River. The work was conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District (CENWP). The CFD results were an invaluable tool for the analysis, both from a Regional and Agency perspective (for the fish passage evaluation) and a CENWP perspective (supporting the BGS design and location). The new CFD model (TDA forebay model) included the latest bathymetry (surveyed in 1999) and a detailed representation of the engineered structures (spillway, powerhouse main, fish, and service units). The TDA forebay model was designed and developed in a way that future studies could easily modify or, to a large extent, reuse large portions of the existing mesh. This study resulted in these key findings: (1) The TDA forebay model matched well with field-measured velocity data. (2) The TDA forebay model matched observations made at the 1:80 general physical model of the TDA forebay. (3) During the course of this study, the methodology typically used by CENWP to contour topographic data was shown to be inaccurate when applied to widely-spaced transect data. Contouring methodologies need to be revisited--especially before such things as modifying the bathymetry in the 1:80 general physical model are undertaken. Future alignments can be evaluated with the model staying largely intact. The next round of analysis will need to address fish passage demands and navigation concerns. CFD models can be used to identify the most promising locations and to provide quantified metrics for biological, hydraulic, and navigation criteria. The most promising locations should then be further evaluated in the 1:80 general physical model.

Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Johnson, Gary E.

2005-03-10T23:59:59.000Z

376

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

377

Rheological properties vs Local Dynamics in model disordered materials at Low Temperature  

E-Print Network [OSTI]

We study the rheological response at low temperature of a sheared model disordered material as a function of the bond rigidity. We find that the flow curves follow a Herschel-Bulkley law, whatever is the bond rigidity, with an exponent close to 0.5. Interestingly, the apparent viscosity can be related to a single relevant time scale $t_{rel}$, suggesting a strong connection between the local dynamics and the global mechanical behaviour. We propose a model based on the competition between the nucleation and the avalanche-like propagation of spatial strain heterogeneities. This model can explain the Herschel-Bulkley exponent on the basis of the size dependence of the heterogeneities on the shear rate.

C. Fusco; T. Albaret; A. Tanguy

2014-03-31T23:59:59.000Z

378

Dynamics of low dimensional model for weakly relativistic Zakharov equations for plasmas  

SciTech Connect (OSTI)

In the present paper, the nonlinear interaction between Langmuir waves and ion acoustic waves described by the one-dimensional Zakharov equations (ZEs) for relativistic plasmas are investigated formulating a low dimensional model. Equilibrium points of the model are found and it is shown that the existence and stability conditions of the equilibrium point depend on the relativistic parameter. Computational investigations are carried out to examine the effects of relativistic parameter and other plasma parameters on the dynamics of the model. Power spectrum analysis using fast fourier transform and also construction of first return map confirm that periodic, quasi-periodic, and chaotic type solution exist for both relativistic as well as in non-relativistic case. Existence of supercritical Hopf bifurcation is noted in the system for two critical plasmon numbers.

Sahu, Biswajit [Department of Mathematics, West Bengal State University, Barasat, Kolkata-700126 (India)] [Department of Mathematics, West Bengal State University, Barasat, Kolkata-700126 (India); Pal, Barnali; Poria, Swarup [Department of Applied Mathematics, University of Calcutta, Kolkata-700009 (India)] [Department of Applied Mathematics, University of Calcutta, Kolkata-700009 (India); Roychoudhury, Rajkumar [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India)] [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India)

2013-05-15T23:59:59.000Z

379

Large scale dynamics of the Persistent Turning Walker model of fish behavior  

E-Print Network [OSTI]

This paper considers a new model of individual displacement, based on fish motion, the so-called Persistent Turning Walker (PTW) model, which involves an Ornstein-Uhlenbeck process on the curvature of the particle trajectory. The goal is to show that its large time and space scale dynamics is of diffusive type, and to provide an analytic expression of the diffusion coefficient. Two methods are investigated. In the first one, we compute the large time asymptotics of the variance of the individual stochastic trajectories. The second method is based on a diffusion approximation of the kinetic formulation of these stochastic trajectories. The kinetic model is a Fokker-Planck type equation posed in an extended phase-space involving the curvature among the kinetic variables. We show that both methods lead to the same value of the diffusion constant. We present some numerical simulations to illustrate the theoretical results.

Pierre Degond; Sébastien Motsch

2007-10-26T23:59:59.000Z

380

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

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Modeling Merging Galaxies using MINGA - Improving Restricted N-body by Dynamical Friction  

E-Print Network [OSTI]

Modeling interacting galaxies to reproduce observed systems is still a challenge due to the extended parameter space (among other problems). Orbit and basic galaxy parameters can be tackled by fast simulation techniques like the restricted N-body method, applied in the fundamental work by Toomre & Toomre (1972). This approach allows today for the study of millions of models in a short time. One difficulty for the classical restricted N-body method is the missing orbital decay, not allowing for galaxy mergers. Here we present an extension of the restricted N-body method including dynamical friction. This treatment has been developed by a quantitative comparison with a set of self-consistent merger simulations. By varying the dynamical friction (formalism, strength and direction), we selected the best-fitting parameters for a set of more than 250000 simulations. We show that our treatment reliably reproduces the orbital decay and tidal features of merging disk galaxies for mass ratios up to q=1/3 between host and satellite. We implemented this technique into our genetic algorithm based modeling code MINGA and present first results.

Hanns P. Petsch; Christian Theis

2008-10-03T23:59:59.000Z

382

Viscosity, relaxation time, and dynamics within a model asphalt of larger molecules  

SciTech Connect (OSTI)

The dynamics properties of a new “next generation” model asphalt system that represents SHRP AAA-1 asphalt using larger molecules than past models is studied using molecular simulation. The system contains 72 molecules distributed over 12 molecule types that range from nonpolar branched alkanes to polar resins and asphaltenes. Molecular weights range from 290 to 890 g/mol. All-atom molecular dynamics simulations conducted at six temperatures from 298.15 to 533.15 K provide a wealth of correlation data. The modified Kohlrausch-Williams-Watts equation was regressed to reorientation time correlation functions and extrapolated to calculate average rotational relaxation times for individual molecules. The rotational relaxation rate of molecules decreased significantly with increasing size and decreasing temperature. Translational self-diffusion coefficients followed an Arrhenius dependence. Similar activation energies of ?42 kJ/mol were found for all 12 molecules in the model system, while diffusion prefactors spanned an order of magnitude. Viscosities calculated directly at 533.15 K and estimated at lower temperatures using the Debye-Stokes-Einstein relationship were consistent with experimental data for asphalts. The product of diffusion coefficient and rotational relaxation time showed only small changes with temperature above 358.15 K, indicating rotation and translation that couple self-consistently with viscosity. At lower temperatures, rotation slowed more than diffusion.

Li, Derek D.; Greenfield, Michael L., E-mail: greenfield@egr.uri.edu [Department of Chemical Engineering, University of Rhode Island, Kingston, Rhode Island 02881 (United States)

2014-01-21T23:59:59.000Z

383

Non-equilibrium structure and dynamics in a microscopic model of thin film active gels  

E-Print Network [OSTI]

In the presence of ATP, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modelling can help to quantify the relationship between individual motors plus filaments to organisation and dynamics on molecular and supra-molecular length scales. Here we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment and detachment, including a differential detachment rate from filament ends, reveals a range of non-equilibrium behaviour. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles or layers, whose stability depends on motor speed and differential end-detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit super-diffusive mass transport, where filament translocation scales with lag time with non-unique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end-detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modelling in the field of active gels.

D. A. Head; W. J. Briels; G. Gompper

2014-02-26T23:59:59.000Z

384

Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.  

SciTech Connect (OSTI)

Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

Meixner, Tom (University of Arizona, Tucson, AZ); Tidwell, Vincent Carroll; Oelsner, Gretchen (University of Arizona, Tucson, AZ); Brooks, Paul (University of Arizona, Tucson, AZ); Roach, Jesse D.

2008-08-01T23:59:59.000Z

385

Non-linear Langevin model for the early-stage dynamics of electrospinning jets  

E-Print Network [OSTI]

We present a non-linear Langevin model to investigate the early-stage dynamics of electrified polymer jets in electrospinning experiments. In particular, we study the effects of air drag force on the uniaxial elongation of the charged jet, right after ejection from the nozzle. Numerical simulations show that the elongation of the jet filament close to the injection point is significantly affected by the non-linear drag exerted by the surrounding air. These result provide useful insights for the optimal design of current and future electrospinning experiments.

Lauricella, Marco; Pisignano, Dario; Succi, Sauro

2015-01-01T23:59:59.000Z

386

Identification of powered parafoil-vehicle dynamics from modelling and flight test data  

E-Print Network [OSTI]

S consisting of N particles P1,...,PN, suppose that n -m gen- eralized speeds have been introduced, and let vPir denote the rth partial velocity of Pi. Then, if Ri is the resultant of all contact and body forces acting on Pi, then the n -m quantities F1,...,Fn-m...IDENTIFICATION OF POWERED PARAFOIL-VEHICLE DYNAMICS FROM MODELLING AND FLIGHT TEST DATA A Dissertation by GI-BONG HUR Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...

Hur, Gi-Bong

2006-08-16T23:59:59.000Z

387

Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing  

SciTech Connect (OSTI)

Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

2011-08-15T23:59:59.000Z

388

Forebay Computational Fluid Dynamics Modeling for The Dalles Dam to Support Vortex Suppress Device Studies  

SciTech Connect (OSTI)

A computational fluid dynamics (CFD) model was used in an investigation into the suppression of a surface vortex that forms and the south-most spilling bay at The Dalles Project. The CFD work complemented work at the prototype and the reduced-scale physical models. The CFD model was based on a model developed for other work in the forebay but had additional resolution added near the spillway. Vortex suppression devices (VSDs) were to placed between pier noses and/or in the bulkhead slot of the spillway bays. The simulations in this study showed that placing VSD structures or a combination of structures to suppress the vortex would still result in near-surface flows to be entrained in a vortex near the downstream spillwall. These results were supported by physical model and prototype studies. However, there was a consensus of the fish biologists at the physical model that the fish would most likely move north and if the fish went under the VSD it would immediately exit the forebay through the tainter gate and not get trapped between VSDs or the VSDs and the tainter gate if the VSDs were deep enough.

Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.

2006-12-01T23:59:59.000Z

389

Mathematical models of infectious disease dynamics --transmission models --have become valuable tools for  

E-Print Network [OSTI]

,anoutbreakofcommunity-acquiredmeticil- lin-resistantStaphylococcusaureus(CA-MRSA).Strainsof CA-MRSA have recently emerged, and one of CA-MRSA in the Los Angeles County Jail (LACJ). We show how to design a within-jail transmission model outbreak; and, third, design effective interventions for outbreak control. The epidemiology of CAMRSA CA-MRSA

Blower, Sally

390

Forest Fire Model as a Supercritical Dynamic Model in Financial Systems  

E-Print Network [OSTI]

Recently, large-scale cascading failures in complex systems have garnered substantial attention. Such extreme events have been treated as an integral part of the self-organized criticality (SOC). Recent empirical work has suggested that some extreme events systematically deviate from the SOC paradigm, requiring a different theoretical framework. We shed additional theoretical light on this possibility by studying financial crisis. We build our model of financial crisis on the well-known forest fire model in scale-free networks. Our analysis shows a non-trivial scaling feature indicating supercritical behavior, which is independent of system size. Extreme events in the supercritical state result from bursting of a fat bubble, seeds of which are sown by a protracted period of a benign financial environment with few shocks. Our findings suggest that policymakers can control the magnitude of financial meltdowns by keeping the economy operating within reasonable duration of a benign environment.

Lee, Deokjae; Lee, Jeho; Kahng, B

2015-01-01T23:59:59.000Z

391

A one-dimensional sectional model to simulate multicomponent aerosol dynamics in the marine boundary layer 1. Model description  

SciTech Connect (OSTI)

A one-dimensional, multicomponent sectional model has been developed to simulate the temporal and vertical variations of the aerosol size distribution and composition in the marine boundary layer (MBL). An important aspect of the model is its ability to handle the transport of aerosols in an atmosphere with humidity gradients with no numerical diffusion caused by the swelling and shrinking of the particles as they move through the humidity gradients. This is achieved by rewriting the aerosol general dynamical equation (GDE) in terms of dry radius thus transferring all variations in radius caused by temporal and spatial humidity variations to the rate coefficients appearing in the equations. The model then solves the new GDE in fixed dry size sections, with the humidity dependence of the processes now included in variable coefficients. This procedure also results in correct gradient transport. A limiting assumption is that the particles equilibrate instantaneously with the ambient water vapor. This assumption limits the maximum particle size which can be treated in the model to ambient (wet) radii less than about 30 {mu}m. All processes currently believed to be important in shaping the MBL size distribution are included in the current version of the model. These include generation of sea-salt aerosol at the ocean surface, nucleation of new particles, coagulation, growth due to condensation of gas-phase reaction products, growth due to sulfate formation during cloud processing, precipitation scavenging, surface deposition, turbulent mixing, gravitational settling, and exchange with the free troposphere. Simple gas-phase chemistry which includes the oxidation of dimethylsulfide and SO{sub 2} to sulfate is incorporated in the current version of the model. {copyright} 1998 American Geophysical Union

Fitzgerald, J.W.; Hoppel, W.A. [Remote Sensing Division, Naval Research Laboratory, Washington, District of Columbia (United States)] [Remote Sensing Division, Naval Research Laboratory, Washington, District of Columbia (United States); Gelbard, F. [Modeling and Analysis Department, Sandia National Laboratories, Albuquerque, New Mexico (United States)] [Modeling and Analysis Department, Sandia National Laboratories, Albuquerque, New Mexico (United States)

1998-07-01T23:59:59.000Z

392

Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.  

SciTech Connect (OSTI)

The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

Mock, Raymond Cecil

2007-06-01T23:59:59.000Z

393

Pygmy and Giant Dipole Resonances by Coulomb Excitation using a Quantum Molecular Dynamics model  

E-Print Network [OSTI]

Pygmy and Giant Dipole Resonance (PDR and GDR) in Ni isotopes have been investigated by Coulomb excitation in the framework of the Isospin-dependent Quantum Molecular Dynamics model (IQMD). The spectra of $\\gamma$ rays are calculated and the peak energy, the strength and Full Width at Half Maximum (FWHM) of GDR and PDR have been extracted. Their sensitivities to nuclear equation of state, especially to its symmetry energy term are also explored. By a comparison with the other mean-field calculations, we obtain the reasonable values for symmetry energy and its slope parameter at saturation, which gives an important constrain for IQMD model. In addition, we also studied the neutron excess dependence of GDR and PDR parameters for Ni isotopes and found that the energy-weighted sum rule (EWSR) $PDR_{m_1}/GDR_{m_1}%$ increases linearly with the neutron excess.

C. Tao; Y. G. Ma; G. Q. Zhang; X. G. Cao; D. Q. Fang. H. W. Wang

2013-02-01T23:59:59.000Z

394

Effect of Interatomic Separation on Entanglement Dynamics in a Two-Atom Two-Mode Model  

E-Print Network [OSTI]

We analyze the time evolution of quantum entanglement in a model consisting of two two-level atoms interacting with a two-mode electromagnetic field for a variety of initial states and interatomic separations. We study two specific atomic separations which give rise to symmetric atom-field couplings. For general atomic distances we consider a subset of initial states analytically, and then treat the more general situation numerically. We examine a variety of qualitative features such as entanglement sudden death, dynamical generation, protection, and transfer between subsystems. Our analysis shows a stark contrast in features of entanglement between the two special coupling schemes often considered; further, these features are uncharacteristic of those arising for general distances, due to the high degree of symmetry present in the special cases. The variety of behaviors in these two-mode cases suggest the importance of considering atomic separation carefully for any model where two atoms interact with a common field.

K. Sinha; N. I. Cummings; B. L. Hu

2011-11-16T23:59:59.000Z

395

Protecting and Dynamically Generating Entanglement in a Two-Atom Two-Field-Mode Model  

E-Print Network [OSTI]

We analyze the time evolution of quantum entanglement in a model consisting of two two-level atoms interacting with a two-mode electromagnetic field for a variety of initial states. We study two different coupling schemes motivated by the forms that can arise due to atomic separation. We observe a variety of qualitative features such as entanglement sudden death, dynamical generation, protection, and transfer between subsystems. Our quantitative analysis shows that these cases with different couplings and initial states differ significantly in these qualitative features. The multifarious behaviors in these two-mode cases suggest the importance of considering atomic separation carefully for any model where two atoms interact with a common field.

K. Sinha; N. Cummings; B. L. Hu

2010-10-06T23:59:59.000Z

396

Cluster Statistics and Quasisoliton Dynamics in Microscopic Car-following Models  

E-Print Network [OSTI]

Using the optimal velocity (OV) model as an example, we show that in the non-linear regime there is an emergent quantity that gives the extremum headways in the cluster formation, as well as the coexistence curve separating the absolute stable phase from the metastable phase. This emergent quantity is independent of the density of the traffic lane, and determines an intrinsic scale that characterizes the dynamics of localized quasisoliton structures given by the time derivative of the headways. The intrinsic scale is analogous to the "charge" of quasisolitons that controls the strength of interaction between multiple clusters, leading to non-trivial cluster statistics from random perturbations to initial uniform traffic. The cluster statistics depend both on the charge and the density of the traffic lane; the relationship is qualitatively universal for general car-following models.

Bo Yang; Xihua Xu; John Z. F. Pang; Christopher Monterola

2014-08-20T23:59:59.000Z

397

A unified electrostatic and cavitation model for first-principles molecular dynamics in solution  

E-Print Network [OSTI]

The electrostatic continuum solvent model developed by Fattebert and Gygi is combined with a first-principles formulation of the cavitation energy based on a natural quantum-mechanical definition for the surface of a solute. Despite its simplicity, the cavitation contribution calculated by this approach is found to be in remarkable agreement with that obtained by more complex algorithms relying on a large set of parameters. Our model allows for very efficient Car-Parrinello simulations of finite or extended systems in solution, and demonstrates a level of accuracy as good as that of established quantum-chemistry continuum solvent methods. We apply this approach to the study of tetracyanoethylene dimers in dichloromethane, providing valuable structural and dynamical insights on the dimerization phenomenon.

Damian A. Scherlis; Jean-Luc Fattebert; Francois Gygi; Matteo Cococcioni; Nicola Marzari

2005-10-06T23:59:59.000Z

398

Projecting Low Dimensional Chaos from Spatio-temporal Dynamics in a Model for Plastic Instability  

E-Print Network [OSTI]

We investigate the possibility of projecting low dimensional chaos from spatiotemporal dynamics of a model for a kind of plastic instability observed under constant strain rate deformation conditions. We first discuss the relationship between the spatiotemporal patterns of the model reflected in the nature of dislocation bands and the nature of stress serrations. We show that at low applied strain rates, there is a one-to-one correspondence with the randomly nucleated isolated bursts of mobile dislocation density and the stress drops. We then show that the model equations are spatiotemporally chaotic by demonstrating the number of positive Lyapunov exponents and Lyapunov dimension scale with the system size at low and high strain rates. Using a modified algorithm for calculating correlation dimension density, we show that the stress-strain signals at low applied strain rates corresponding to spatially uncorrelated dislocation bands exhibit features of low dimensional chaos. This is made quantitative by demonstrating that the model equations can be approximately reduced to space independent model equations for the average dislocation densities, which is known to be low-dimensionally chaotic. However, the scaling regime for the correlation dimension shrinks with increasing applied strain rate due to increasing propensity for propagation of the dislocation bands.

Ritupan Sarmah; G. Ananthakrishna

2013-03-26T23:59:59.000Z

399

EARLY DYNAMICAL EVOLUTION OF THE SOLAR SYSTEM: PINNING DOWN THE INITIAL CONDITIONS OF THE NICE MODEL  

SciTech Connect (OSTI)

In the recent years, the 'Nice' model of solar system formation has attained an unprecedented level of success in reproducing much of the observed orbital architecture of the solar system by evolving the planets to their current locations from a more compact configuration. Within the context of this model, the formation of the classical Kuiper Belt requires a phase during which the ice giants have a high eccentricity. An outstanding question of this model is the initial configuration from which the solar system started out. Recent work has shown that multi-resonant initial conditions can serve as good candidates, as they naturally prevent vigorous type-II migration. In this paper, we use analytical arguments, as well as self-consistent numerical N-body simulations to identify fully resonant initial conditions, whose dynamical evolution is characterized by an eccentric phase of the ice giants, as well as planetary scattering. We find a total of eight such initial conditions. Four of these primordial states are compatible with the canonical 'Nice' model, while the others imply slightly different evolutions. The results presented here should prove useful in further development of a comprehensive model for solar system formation.

Batygin, Konstantin; Brown, Michael E., E-mail: kbatygin@gps.caltech.ed [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

2010-06-20T23:59:59.000Z

400

Three-Dimensional Computational Fluid Dynamics Modeling of Solid Oxide Electrolysis Cells and Stacks  

SciTech Connect (OSTI)

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created for detailed analysis of a high-temperature electrolysis stack (solid oxide fuel cells operated as electrolyzers). Inlet and outlet plenum flow distributions are discussed. Maldistribution of plena flow show deviations in per-cell operating conditions due to non-uniformity of species concentrations. Models have also been created to simulate experimental conditions and for code validation. Comparisons between model predictions and experimental results are discussed. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the electrolysis mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition.

Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring

2008-07-01T23:59:59.000Z

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401

A Hidden Markov Model of atomic quantum jump dynamics in an optically probed cavity  

E-Print Network [OSTI]

We analyze the quantum jumps of an atom interacting with a cavity field. The strong atom- field interaction makes the cavity transmission depend on the time dependent atomic state, and we present a Hidden Markov Model description of the atomic state dynamics which is conditioned in a Bayesian manner on the detected signal. We suggest that small variations in the observed signal may be due to spatial motion of the atom within the cavity, and we represent the atomic system by a number of hidden states to account for both the small variations and the internal state jump dynamics. In our theory, the atomic state is determined in a Bayesian manner from the measurement data, and we present an iterative protocol, which determines both the atomic state and the model parameters. As a new element in the treatment of observed quantum systems, we employ a Bayesian approach that conditions the atomic state at time t on the data acquired both before and after t and we show that the state assignment by this approach is more decisive than the usual conditional quantum states, based on only earlier measurement data.

S. Gammelmark; W. Alt; T. Kampschulte; D. Meschede; K. Molmer

2014-05-02T23:59:59.000Z

402

Exact Coherent Structures and Chaotic Dynamics in a Model of Cardiac Tissue  

E-Print Network [OSTI]

Unstable nonchaotic solutions embedded in the chaotic attractor can provide significant new insight into chaotic dynamics of both low- and high-dimensional systems. In particular, in turbulent fluid flows, such unstable solutions are referred to as exact coherent structures (ECS) and play an important role in both initiating and sustaining turbulence. The nature of ECS and their role in organizing spatiotemporally chaotic dynamics, however, is reasonably well understood only for systems on relatively small spatial domains lacking continuous Euclidean symmetries. Construction of ECS on large domains and in the presence of continuous translational and/or rotational symmetries remains a challenge. This is especially true for models of excitable media which display spiral turbulence and for which the standard approach to computing ECS completely breaks down. This paper uses the Karma model of cardiac tissue to illustrate a potential approach that could allow computing a new class of ECS on large domains of arbitrary shape by decomposing them into a patchwork of solutions on smaller domains, or tiles, which retain Euclidean symmetries locally.

Greg Byrne; Christopher D. Marcotte; Roman O. Grigoriev

2015-01-20T23:59:59.000Z

403

Modeling surfaces in the context of pulsed-power : work functions, electron emission and dynamic response.  

SciTech Connect (OSTI)

The ability to quickly understand and deal with issues on ZR, or to virtually design a future ZX accelerator, requires a physics-based capability to simulate all key pulsed power components. Highly important for gas switches and transmission lines are surface phenomena: thermionic emission, photoemission, field emission, and ion-surface dynamics. These are complex processes even at normal conditions, when coupled to the dynamic environment in pulsed power components, the current state of the art of understanding is not at the level of science based predictive modeling. Modeling efforts at the macroscopic level (finite element based hydrodynamic simulations) require detailed information of these processes to yield more reliable results. This is the final report of an LDRD project in the science of extreme environments investment area; the project was focused on describing the physics of surfaces of materials of interest in pulsed-power components. We have calculated the temperature dependence of work functions for metals from first principles using density functional theory (DFT) as well as investigated the effect of initial oxidation and alloying. By using the GW method, we have gone beyond DFT to calculate work functions for Al. The GW work required base-lining the GW results for different systems, since GW lacks a description of total energy. Lastly, we investigated the more macroscopic physics of how a surface and bulk material responds to a very high current under a short time, representative for current loads in pulsed-power components, with emphasis on materials modeling. These simulations were made using two hydrodynamic codes, ALEGRA and MACH2, in order to focus on the materials models themselves.

Cochrane, Kyle Robert (Ktech Corporation, Albuquerque, NM); Chantrenne, Sophie (SAIC, Albuquerque, NM); Mattsson, Thomas Kjell Rene; Faleev, Sergey V. (SNAMI Inc., AL)

2009-09-01T23:59:59.000Z

404

Steady-State and Dynamic Modeling of Gas-Phase Polypropylene Processes Using Stirred-Bed Reactors  

E-Print Network [OSTI]

Steady-State and Dynamic Modeling of Gas-Phase Polypropylene Processes Using Stirred-Bed Reactors for the continuous gas-phase synthesis of polypropylene using stirred-bed reactors. The model considers the important- terization, and reactor residence time, in addition to the traditional Ziegler-Natta polymerization kinetics

Liu, Y. A.

405

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass-transition region  

E-Print Network [OSTI]

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass 2004; published online 17 February 2005 A phenomenological model of electron transfer reactions-acceptor energy gaps dashed line in Fig. 1 differs from the equilibrium distribution. The present phenomenological

Matyushov, Dmitry

406

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 27, NO. 1, FEBRUARY 2012 465 Dynamics of Type-3 Wind Turbine Generator Models  

E-Print Network [OSTI]

Turbine Generator Models Ian A. Hiskens, Fellow, IEEE Abstract--The influence of wind turbine generators, singular systems, small disturbance analysis, switching deadlock, wind turbine generator modeling. I. INTRODUCTION THE dynamic behavior of wind turbine generators (WTGs) is quite different to that of synchronous

Hiskens, Ian A.

407

Vacancy diffusion in colloidal crystals as determined by dynamical density-functional theory and the phase-field-crystal model  

E-Print Network [OSTI]

A two-dimensional crystal of repulsive dipolar particles is studied in the vicinity of its melting transition by using Brownian dynamics computer simulation, dynamical density functional theory and phase-field crystal modelling. A vacancy is created by taking out a particle from an equilibrated crystal and the relaxation dynamics of the vacancy is followed by monitoring the time-dependent one-particle density. We find that the vacancy is quickly filled up by diffusive hopping of neighbouring particles towards the vacancy center. We examine the temperature dependence of the diffusion constant and find that it decreases with decreasing temperature in the simulations. This trend is reproduced by the dynamical density functional theory. Conversely, the phase field crystal calculations predict the opposite trend. Therefore, the phase-field model needs a temperature-dependent expression for the mobility to predict trends correctly.

Sven van Teeffelen; Cristian Vasile Achim; Hartmut Löwen

2013-02-05T23:59:59.000Z

408

Dynamical modelling of luminous and dark matter in 17 Coma early-type galaxies  

E-Print Network [OSTI]

Dynamical models for 17 Coma early-type galaxies are presented. The galaxy sample consists of flattened, rotating as well as non-rotating early-types including cD and S0 galaxies with luminosities between M=-18.79 and M=-22.56. Kinematical long-slit observations cover at least the major and minor axis and extend to 1-4 effective radii. Axisymmetric Schwarzschild models are used to derive stellar mass-to-light ratios and dark halo parameters. In every galaxy models with a dark matter halo match the data better than models without. The statistical significance is over 95 percent for 8 galaxies, around 90 percent for 5 galaxies and for four galaxies it is not significant. For the highly significant cases systematic deviations between observed and modelled kinematics are clearly seen; for the remaining galaxies differences are more statistical in nature. Best-fit models contain 10-50 percent dark matter inside the half-light radius. The central dark matter density is at least one order of magnitude lower than the luminous mass density. The central phase-space density of dark matter is often orders of magnitude lower than in the luminous component, especially when the halo core radius is large. The orbital system of the stars along the major-axis is slightly dominated by radial motions. Some galaxies show tangential anisotropy along the minor-axis, which is correlated with the minor-axis Gauss-Hermite coefficient H4. Changing the balance between data-fit and regularisation constraints does not change the reconstructed mass structure significantly. Model anisotropies tend to strengthen if the weight on regularisation is reduced, but the general property of a galaxy to be radially or tangentially anisotropic, respectively, does not change. (abridged)

J. Thomas; R. P. Saglia; R. Bender; D. Thomas; K. Gebhardt; J. Magorrian; E. M. Corsini; G. Wegner

2007-09-05T23:59:59.000Z

409

Simulation of dynamic fracture using peridynamics, finite element modeling, and contact.  

SciTech Connect (OSTI)

Peridynamics is a nonlocal extension of classical solid mechanics that allows for the modeling of bodies in which discontinuities occur spontaneously. Because the peridynamic expression for the balance of linear momentum does not contain spatial derivatives and is instead based on an integral equation, it is well suited for modeling phenomena involving spatial discontinuities such as crack formation and fracture. In this study, both peridynamics and classical finite element analysis are applied to simulate material response under dynamic blast loading conditions. A combined approach is utilized in which the portion of the simulation modeled with peridynamics interacts with the finite element portion of the model via a contact algorithm. The peridynamic portion of the analysis utilizes an elastic-plastic constitutive model with linear hardening. The peridynamic interface to the constitutive model is based on the calculation of an approximate deformation gradient, requiring the suppression of possible zero-energy modes. The classical finite element portion of the model utilizes a Johnson-Cook constitutive model. Simulation results are validated by direct comparison to expanding tube experiments. The coupled modeling approach successfully captures material response at the surface of the tube and the emerging fracture pattern. The coupling of peridynamics and finite element analysis via a contact algorithm has been shown to be a viable means for simulating material fracture in a high-velocity impact experiment. A combined peridynamics/finite element approach was applied to model an expanding tube experiment performed by Vogler, et al., in which loading on the tube is a result of Lexan slugs impacting inside the tube. The Lexan portion of the simulation was modeled with finite elements and a Johnson-Cook elastic-plastic material model in conjunction with an equation-of-state law. The steel tube portion of the simulation was modeled with peridynamics, an elastic-plastic material model, and a critical stretch bond damage model. The application of peridynamics to the tube portion of the model allowed the capture of the formation of cracks and eventual fragmentation of the tube. The simulation results yielded good agreement with the experimental results published by Vogler, et al., for the velocity and displacement profiles on the surface of the tube and the resulting fragment distribution. Numerical difficulties were encountered that required removal of hexahedron elements from the Lexan portion of the model over the course of the simulation. The significant number of inverted and nearly-inverted elements appearing over the course of the simulation is believed to be a result of irregularities in the contact between the Lexan and AerMet portions of the model, and was likely exacerbated by the ultra-high strength of the AerMet tube. Future simulations are planned in which the Lexan portion of the simulation is modeled with peridynamics, or with an alternative method such as smoothed particle hydrodynamics, with the goal of reducing these numerical difficulties.

Littlewood, David John

2010-11-01T23:59:59.000Z

410

Dynamical coupled-channels model of $K^- p$ reactions (I): Determination of partial-wave amplitudes  

E-Print Network [OSTI]

We develop a dynamical coupled-channels model of K^- p reactions, aiming at extracting the parameters associated with hyperon resonances and providing the elementary antikaon-nucleon scattering amplitudes that can be used for investigating various phenomena in the strangeness sector such as the production of hypernuclei from kaon-nucleus reactions. The model consists of (a) meson-baryon (MB) potentials v_{M'B',MB} derived from the phenomenological SU(3) Lagrangian, and (b) vertex interactions Gamma_{MB,Y*} for describing the decays of the bare excited hyperon states (Y*) into MB states. The model is defined in a channel space spanned by the two-body barK N, pi Sigma, pi Lambda, eta Lambda, and K Xi states and also the three-body pi pi Lambda and pi barK N states that have the resonant pi Sigma* and barK* N components, respectively. The resulting coupled-channels scattering equations satisfy the multichannel unitarity conditions and account for the dynamical effects arising from the off-shell rescattering processes. The model parameters are determined by fitting the available data of the unpolarized and polarized observables of the K^- p --> barK N, pi Sigma, pi Lambda, eta Lambda, K Xi reactions in the energy region from the threshold to invariant mass W=2.1 GeV. Two models with equally good chi^2 fits to the data have been constructed. The partial-wave amplitudes obtained from the constructed models are compared with the results from a recent partial-wave analysis by the Kent State University group. We discuss the differences between these three analysis results. Our results at energies near the threshold suggest that the higher partial waves should be treated on the same footing as the S wave if one wants to understand the nature of Lambda(1405)1/2^- using the data below the barK N threshold, as will be provided by the J-PARC E31 experiment.

H. Kamano; S. X. Nakamura; T. -S. H. Lee; T. Sato

2014-12-12T23:59:59.000Z

411

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

412

Preliminary results of a dynamic system model for a closed-loop Brayton cycle coupled to a nuclear reactor.  

SciTech Connect (OSTI)

This paper describes preliminary results of a dynamic system model for a closed-loop Brayton-cycle that is coupled to a nuclear reactor. The current model assumes direct coupling between the reactor and the Brayton-cycle, however only minor additions are required to couple the Brayton-cycle through a heat exchanger to either a heat pipe reactor or a liquid metal cooled reactor. Few reactors have ever been coupled to closed Brayton-cycle systems. As such their behavior under dynamically varying loads, startup and shut down conditions, and requirements for safe and autonomous operation are largely unknown. Sandia National Laboratories has developed steady-state and dynamic models for closed-loop turbo-compressor systems (for space and terrestrial applications). These models are expected to provide a basic understanding of the dynamic behavior and stability of the coupled reactor and power generation loop. The model described in this paper is a lumped parameter model of the reactor, turbine, compressor, recuperator, radiator/waste-heat-rejection system and generator. More detailed models that remove the lumped parameter simplifications are also being developed but are not presented here. The initial results of the model indicate stable operation of the reactor-driven Brayton-cycle system and its ability to load-follow. However, the model also indicates some counter-intuitive behavior for the complete coupled system. This behavior will require the use of a reactor control system to select an appropriate reactor operating temperature that will optimize the performance of the complete spacecraft system. We expect this model and subsequent versions of it to provide crucial information in developing procedures for safe start up, shut down, safe-standby, and other autonomous operating modes. Ultimately, Sandia hopes to validate these models and to perform nuclear ground tests of reactor-driven closed Brayton-cycle systems in our nuclear research facilities.

Wright, Steven Alan

2003-06-01T23:59:59.000Z

413

Essays in dynamic contracting  

E-Print Network [OSTI]

This thesis examines three models of dynamic contracting. The first model is a model of dynamic moral hazard with partially persistent states, and the second model considers relational contracts when the states are partially ...

Kwon, Suehyun

2012-01-01T23:59:59.000Z

414

Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment  

SciTech Connect (OSTI)

Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases.

Kaper, Tasso J., E-mail: tasso@bu.edu; Kramer, Mark A., E-mail: mak@bu.edu [Department of Mathematics and Statistics, Boston University, Boston, Massachusetts 02215 (United States); Rotstein, Horacio G., E-mail: horacio@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

2013-12-15T23:59:59.000Z

415

The Ising Model on a Dynamically Triangulated Disk with a Boundary Magnetic Field  

E-Print Network [OSTI]

We use Monte Carlo simulations to study a dynamically triangulated disk with Ising spins on the vertices and a boundary magnetic field. For the case of zero magnetic field we show that the model possesses three phases. For one of these the boundary length grows linearly with disk area, while the other two phases are characterized by a boundary whose size is on the order of the cut-off. A line of continuous magnetic transitions separates the two small boundary phases. We determine the critical exponents of the continuous magnetic phase transition and relate them to predictions from continuum 2-d quantum gravity. This line of continuous transitions appears to terminate on a line of discontinuous phase transitions dividing the small boundary phases from the large boundary phase. We examine the scaling of bulk magnetization and boundary magnetization as a function of boundary magnetic field in the vicinity of this tricritical point.

Scott McGuire; Simon Catterall; Mark Bowick; Simeon Warner

2001-05-02T23:59:59.000Z

416

Flow modeling of flat oval ductwork elbows using computational fluid dynamics  

SciTech Connect (OSTI)

Incompressible turbulent flow fields in heating, ventilating, and air-conditioning (HVAC) elbows were computed using an incompressible, three-dimensional computational fluid dynamics (CFD) solver implementing a {kappa}-{epsilon} turbulence model. Two different geometries were investigated, including 90-degree five-gore hard-bend and easy-bend flat oval elbows. The geometries represent a subset of many configurations analyzed in ASHRAE RP-854, Determination of Duct Fitting Resistance by Numerical Analysis. For each configuration, the zero-length pressure loss coefficient was calculated. The flow was described through contours of velocity and plots of static pressure. The Reynolds number for these flows was held constant at 100,000 based on duct diameter and mean fluid velocity.

Mahank, T.A.; Mumma, S.A. [Pennsylvania State Univ., University Park, PA (United States)

1997-12-31T23:59:59.000Z

417

Computational Intelligence Based Data Fusion Algorithm for Dynamic sEMG and Skeletal Muscle Force Modelling  

SciTech Connect (OSTI)

In this work, an array of three surface Electrography (sEMG) sensors are used to acquired muscle extension and contraction signals for 18 healthy test subjects. The skeletal muscle force is estimated using the acquired sEMG signals and a Non-linear Wiener Hammerstein model, relating the two signals in a dynamic fashion. The model is obtained from using System Identification (SI) algorithm. The obtained force models for each sensor are fused using a proposed fuzzy logic concept with the intent to improve the force estimation accuracy and resilience to sensor failure or misalignment. For the fuzzy logic inference system, the sEMG entropy, the relative error, and the correlation of the force signals are considered for defining the membership functions. The proposed fusion algorithm yields an average of 92.49% correlation between the actual force and the overall estimated force output. In addition, the proposed fusionbased approach is implemented on a test platform. Experiments indicate an improvement in finger/hand force estimation.

Chandrasekhar Potluri,; Madhavi Anugolu; Marco P. Schoen; D. Subbaram Naidu

2013-08-01T23:59:59.000Z

418

Dynamical properties of high-temperature-superconductor granular bridge junctions: Inhomogeneous Josephson-junction-array model  

SciTech Connect (OSTI)

As an attempt to understand the dynamical behavior of the high-temperature-superconductor (HTSC) granular bridge junction, we model the granular HTSC bridge junction consisting of many small grains inside by an inhomogeneous Josephson junction array, i.e., randomly arranged Josephson junction arrays (JJA). To describe randomly distributed critical currents between the grains inside the HTSC granular bridge junction, we chose various possible configurations in {l_brace}{ital I}{sub {ital ij}}{sup {ital c}}{r_brace} and {l_brace}{ital R}{sub {ital ij}}{r_brace} for the one-dimensional (1D) and 2D inhomogeneous Josephson junctions, and calculated the current-voltage ({ital IV}) characteristics and self-radiation spectral densities of the 1D and 2D inhomogeneous Josephson junctions. As a result, depending upon the distribution of critical currents and shunted resistances, it is found that there are large variations of {ital IV} characteristics. In contrast to the appearance of giant Shapiro steps in the regular ordered array, such Shapiro steps disappear in the case of the disordered JJA due to the increased randomness in the distribution of critical currents. On the contrary, however, when there exists a correlation between critical currents and resistances, i.e., a constant Josephson voltage, {ital I}{sub {ital ij}}{sup {ital c}}{ital R}{sub {ital ij}}={ital V}{sub {ital J}} (constant), the fundamental Shapiro step emerges despite the disordered distribution of {ital I}{sub {ital ij}}{sup {ital c}}. The relevance of this model to the HTSC granular bridge junctions is discussed. In particular, experimentally observed dynamical behaviors of the HTSC granular bridge junctions are shown to be closely related to the case of the correlated distribution with constant Josephson voltage. {copyright} {ital 1996 The American Physical Society.}

Lee, J.; Lee, S.; Yu, J.; Park, G. [Department of Physics, Sogang University, Seoul 121-742 (Korea)] [Department of Physics, Sogang University, Seoul 121-742 (Korea)

1996-02-01T23:59:59.000Z

419

Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects  

SciTech Connect (OSTI)

In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods is less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on the relative size of the transient storage zone and how it changes in the downstream direction, as well as the nature of hydrologic variability.

Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu; Basu, Nandita; Li, Hongyi; Wang, Shaowen

2012-06-30T23:59:59.000Z

420

Calculation of the distribution of eigenvalues and eigenvectors in Markovian state models for molecular dynamics  

E-Print Network [OSTI]

such as Folding@Home.1 After generating large ensembles of molecular dynamics simulations, we wish to analyze

Hinrichs, Nina Singhal

Note: This page contains sample records for the topic "dynamics model redyn" 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

A LUMPED-PARAMETER DYNAMIC MODEL OF A THERMAL REGENERATOR FOR FREE-PISTON STIRLING ENGINES  

E-Print Network [OSTI]

to the other, the heat transfer, and the load dynamics, a self sustaining cycle can be obtained to transform

Barth, Eric J.

422

Minimizing the Electricity Bill of Cooperative Users under a Quasi-Dynamic Pricing Model  

E-Print Network [OSTI]

- Systems {shatami,pedram}@usc.edu Abstract--Dynamic energy pricing is a promising development use at different times during a fixed interval based on dynamic energy prices during that interval-interruptible or interruptible jobs. The methods relay on a quasi-dynamic pricing function for unit of energy consumed, which

Pedram, Massoud

423

Three-dimensional Computational Fluid Dynamics (CFD) modeling of dry spent nuclear fuel storage canisters  

SciTech Connect (OSTI)

One of the interim storage configurations being considered for aluminum-clad foreign research reactor fuel, such as the Material and Testing Reactor (MTR) design, is in a dry storage facility. To support design studies of storage options, a computational and experimental program was conducted at the Savannah River Site (SRS). The objective was to develop computational fluid dynamics (CFD) models which would be benchmarked using data obtained from a full scale heat transfer experiment conducted in the SRS Experimental Thermal Fluids Laboratory. The current work documents the CFD approach and presents comparison of results with experimental data. CFDS-FLOW3D (version 3.3) CFD code has been used to model the 3-dimensional convective velocity and temperature distributions within a single dry storage canister of MTR fuel elements. For the present analysis, the Boussinesq approximation was used for the consideration of buoyancy-driven natural convection. Comparison of the CFD code can be used to predict reasonably accurate flow and thermal behavior of a typical foreign research reactor fuel stored in a dry storage facility.

Lee, S.Y.

1997-06-01T23:59:59.000Z

424

Wind Turbine Modeling for Computational Fluid Dynamics: December 2010 - December 2012  

SciTech Connect (OSTI)

With the shortage of fossil fuel and the increasing environmental awareness, wind energy is becoming more and more important. As the market for wind energy grows, wind turbines and wind farms are becoming larger. Current utility-scale turbines extend a significant distance into the atmospheric boundary layer. Therefore, the interaction between the atmospheric boundary layer and the turbines and their wakes needs to be better understood. The turbulent wakes of upstream turbines affect the flow field of the turbines behind them, decreasing power production and increasing mechanical loading. With a better understanding of this type of flow, wind farm developers could plan better-performing, less maintenance-intensive wind farms. Simulating this flow using computational fluid dynamics is one important way to gain a better understanding of wind farm flows. In this study, we compare the performance of actuator disc and actuator line models in producing wind turbine wakes and the wake-turbine interaction between multiple turbines. We also examine parameters that affect the performance of these models, such as grid resolution, the use of a tip-loss correction, and the way in which the turbine force is projected onto the flow field.

Tossas, L. A. M.; Leonardi, S.

2013-07-01T23:59:59.000Z

425

Modelling of the dynamics of a low-speed gas-liquid heat engine  

SciTech Connect (OSTI)

This paper deals with the simulation model of a gas-liquid heat engine which is characterized by very low speeds (1-3 rpm) and relatively high torque. The engine operates according to the Minto Thermal Wheel' principle. It is based on the conversion of thermal energy from the heat source, through gas expansion, into mechanical work, by means of the fall of a mass of liquid. A prototype has already been constructed showing great ability to operate at very low temperature differences between the heat source and heat sink. This makes the engine quite suitable to the utilization of low temperature heat sources such as solar energy and waste heat. On the other hand, the number of moving parts is kept to a minimum, since the piston of traditional positive displacement engines (PDE) is now replaced simply by a mass of liquid. The mathematical model consists of applying the energy equation, in it time-derivative form, to representative engine control volumes, resulting in a set of linear ordinary differential equations. Their integration provides the time variation of pressure and temperature of the working fluid. The engine performance can thus be predicted as a function of engine operating conditions and geometric characteristics. In this paper, the engine dynamics (i.e., variable angular speed) have been taken into account, as well as heat losses in the engine structure. Results and further design considerations are discussed.

Cunha, C.M.P.; Parise, J.A.R. (Pontificia Univ. Catolica do Rio de Janeiro (Brazil))

1992-01-01T23:59:59.000Z

426

A dynamical model of supernova feedback: gas outflows from the interstellar medium  

E-Print Network [OSTI]

We present a dynamical model of supernova feedback which follows the evolution of pressurised bubbles driven by supernovae in a multi-phase interstellar medium (ISM). The bubbles are followed until the point of break-out into the halo, starting from an initial adiabatic phase to a radiative phase. We show that a key property which sets the fate of bubbles in the ISM is the gas surface density, through the work done by the expansion of bubbles and its role in setting the gas scaleheight. The multi-phase description of the ISM is essential, and neglecting it leads to order of magnitude differences in the predicted outflow rates. We compare our predicted mass loading and outflow velocities to observations of local and high-redshift galaxies and find good agreement. With the aim of analysing the dependence of the mass loading of the outflow, $\\beta$ (i.e. the ratio between the outflow and star formation rates), on galaxy properties, we embed our model in the galaxy formation simulation, GALFORM, set in the $\\Lamb...

Lagos, Claudia; Baugh, C M

2013-01-01T23:59:59.000Z

427

Quadrupole collective dynamics from energy density functionals: Collective Hamiltonian and the interacting boson model  

SciTech Connect (OSTI)

Microscopic energy density functionals have become a standard tool for nuclear structure calculations, providing an accurate global description of nuclear ground states and collective excitations. For spectroscopic applications, this framework has to be extended to account for collective correlations related to restoration of symmetries broken by the static mean field, and for fluctuations of collective variables. In this paper, we compare two approaches to five-dimensional quadrupole dynamics: the collective Hamiltonian for quadrupole vibrations and rotations and the interacting boson model (IBM). The two models are compared in a study of the evolution of nonaxial shapes in Pt isotopes. Starting from the binding energy surfaces of {sup 192,194,196}Pt, calculated with a microscopic energy density functional, we analyze the resulting low-energy collective spectra obtained from the collective Hamiltonian, and the corresponding IBM Hamiltonian. The calculated excitation spectra and transition probabilities for the ground-state bands and the {gamma}-vibration bands are compared to the corresponding sequences of experimental states.

Nomura, K.; Vretenar, D. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Physics Department, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Niksic, T. [Physics Department, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Otsuka, T. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Shimizu, N. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2011-07-15T23:59:59.000Z

428

Scientific Final Report: 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.

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

2012-04-09T23:59:59.000Z

429

Soil Dynamics and Earthquake Engineering 26 (2006) 694707 Plain strain soilstructure interaction model for a building supported by  

E-Print Network [OSTI]

Soil Dynamics and Earthquake Engineering 26 (2006) 694­707 Plain strain soil­structure interaction, CA 90089-2531, USA Accepted 3 January 2006 Abstract A simple theoretical model for soil­structure interaction in water saturated poroelastic soils is presented, developed to explore if the apparent building­foundation­soil

Southern California, University of

2006-01-01T23:59:59.000Z

430

New Dynamic Models for Planar Extensible Continuum Robot Manipulators Enver Tatlicioglu, Ian D. Walker, and Darren M. Dawson  

E-Print Network [OSTI]

or an octopus arm [15]. It is a three-section robot with nine degrees of freedom where each section hasNew Dynamic Models for Planar Extensible Continuum Robot Manipulators Enver Tatlicioglu, Ian D 3-section extensible continuum robot manipulator. The results show a much stronger match to physical

431

Theory of spiral wave dynamics in weakly excitable media: Asymptotic reduction to a kinematic model and applications  

E-Print Network [OSTI]

Theory of spiral wave dynamics in weakly excitable media: Asymptotic reduction to a kinematic model of an isolated broken plane wave ~wave tip! can either rotate ~steadily or unsteadily! around a large excitable core, thereby producing a spiral pattern, or retract, causing the wave to vanish at boundaries

Hakim, Vincent

432

Dynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation by using inlet  

E-Print Network [OSTI]

and modification.1 The co-rotating twin-screw extruder is of particular interest due to its modular geometry or removing chemical species.3,4 Furthermore, the co-rotating twin-screw extruder can handle high viscosityDynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation

Paris-Sud XI, Université de

433

IEA Heat Pump Conference 2011, 16 -19 May 2011, Tokyo, Japan DYNAMIC MODELING OF AN AIR SOURCE HEAT PUMP WATER  

E-Print Network [OSTI]

. Compared to those water heaters, heat pump water heating systems can supply much more heat just with the same amount of electric input used for electric water heaters. The ASHPWH absorbs heat from the ambient- 1 - 10th IEA Heat Pump Conference 2011, 16 - 19 May 2011, Tokyo, Japan DYNAMIC MODELING OF AN AIR

Paris-Sud XI, Université de

434

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)

435

Abstract--Friction modeling is essential for joint dynamic identification and control. Joint friction is composed of a  

E-Print Network [OSTI]

Abstract--Friction modeling is essential for joint dynamic identification and control. Joint friction is composed of a viscous and a dry friction force. According to Coulomb law, dry friction depends linearly on the load in the transmission. However, in robotics field, a constant dry friction is frequently

Paris-Sud XI, Université de

436

Modeling substorm dynamics of the magnetosphere: From self-organization and self-organized criticality to nonequilibrium phase transitions  

E-Print Network [OSTI]

, this exponent relates input and output parameters of the magnetosphere. Using an analogy to the dynamical Ising model in the mean-field approximation, we show the connection between the data-derived exponent in the flow of the plasma coming from the Sun solar wind . Part of the solar wind energy penetrates

Sitnov, Mikhail I.

437

Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics Processing Unit  

E-Print Network [OSTI]

Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics solve Navier-Stokes equations and other transportation equations for energy and species at a speed of 50 it in parallel on a Graphics Processing Unit (GPU). This study validated the FFD on the GPU by simulating

Chen, Qingyan "Yan"

438

Dynamic Force/Position Modeling of a one-DOF Smart Piezoelectric Micro-Finger with Sensorized End-Effector  

E-Print Network [OSTI]

microscale system is studied where a smart microsystem composed of an active based material actuatorDynamic Force/Position Modeling of a one-DOF Smart Piezoelectric Micro-Finger with Sensorized End enables to understand the interaction between the complete smart microsystem and the environment

Boyer, Edmond

439

Comments to support the Dipole Dynamical Model (DDM) of Ball Lightning (BL)  

E-Print Network [OSTI]

I present estimates to justify previously proposed by me heuristic Dipole Dynamical Model (DDM) of Ball Lightning (BL). The movement and energy supplying to the dipole BL are due to the atmospheric electric field. Crucial for the detailed analysis of BL is using the new relation of balance of the force of atmospheric electric field (per unit mass of electron cloud) and dipole forces electrons-ions within BL dipole (per unit mass of BL) as the first necessary condition for the existance of BL as an integer. This model is unique because, unlike existing static models, fundamental condition for the existence of Ball Lightning is its forward motion. The virial theorem limiting BL power does not apply to BL which is not closed system like the Sun or Galaxy systems and is strongly dependent part of the infinitely extended in time and space large system. Stability of BL is due to two free parameters with the fundamental role of thermodynamic non-equilibrium, ionization, recombination and translational movement with energy loss by radiation and also excess volumetric positive charge. Polarization degree of BL plasma is characterized by polarizability factor {\\gamma}. An example is presented of calculating the stability of option BL. There is also a possible connection of stability BL with statistical distributions of the atmospheric electric field in time and space. Destruction of BL can also occur due to arising kinematical instability at its accelerating (or decelerating) movement. Maximal energy density in BL DDM does not exceed the value Espec<(10(8) - 10(9)) J/m(3). Resulting indefinitely long BL lifetime is also discussed.

V. N. Soshnikov

2015-02-01T23:59:59.000Z

440

Molecular dynamics simulation: a tool for exploration and discovery using simple models  

E-Print Network [OSTI]

Emergent phenomena share the fascinating property of not being obvious consequences of the design of the system in which they appear. This characteristic is no less relevant when attempting to simulate such phenomena, given that the outcome is not always a foregone conclusion. The present survey focuses on several simple model systems that exhibit surprisingly rich emergent behavior, all studied by MD simulation. The examples are taken from the disparate fields of fluid dynamics, granular matter and supramolecular self-assembly. In studies of fluids modeled at the detailed microscopic level using discrete particles, the simulations demonstrate that complex hydrodynamic phenomena in rotating and convecting fluids, the Taylor-Couette and Rayleigh-B\\'enard instabilities, can not only be observed within the limited length and time scales accessible to MD, but even quantitative agreement can be achieved. Simulation of highly counterintuitive segregation phenomena in granular mixtures, again using MD methods, but now augmented by forces producing damping and friction, leads to results that resemble experimentally observed axial and radial segregation in the case of a rotating cylinder, and to a novel form of horizontal segregation in a vertically vibrated layer. Finally, when modeling self-assembly processes analogous to the formation of the polyhedral shells that package spherical viruses, simulation of suitably shaped particles reveals the ability to produce complete, error-free assembly, and leads to the important general observation that reversible growth steps contribute to the high yield. While there are limitations to the MD approach, both computational and conceptual, the results offer a tantalizing hint of the kinds of phenomena that can be explored, and what might be discovered when sufficient resources are brought to bear on a problem.

D. C. Rapaport

2014-11-13T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Proceedings ASCE EWRI World Water and Environmental Resources Congress 2005 May 15-19, 2005 Modeling and evaluating temperature dynamics in wastewater treatment plants  

E-Print Network [OSTI]

Modeling and evaluating temperature dynamics in wastewater treatment plants Scott A. Wells1 , Dmitriy into receiving waters, there is much interest in providing a model of temperature dynamics in wastewater using detailed temperature data from a Washington County, Oregon, USA wastewater treatment facility

Wells, Scott A.

442

Protein Dynamics and Biocatalysis  

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

Protein Dynamics and Biocatalysis Protein Dynamics and Biocatalysis 1998 Annual Report Grand Challenge Projects biocatalysis.gif A model of the Michaelis complex for the TEM-1...

443

Dynamical aspects of the plane-wave matrix model at finite temperature  

E-Print Network [OSTI]

We study dynamical aspects of the plane-wave matrix model at finite temperature. One-loop calculation around general classical vacua is performed using the background field method, and the integration over the gauge field moduli is carried out both analytically and numerically. In addition to the trivial vacuum, which corresponds to a single M5-brane at zero temperature, we consider general static fuzzy-sphere type configurations. They are all 1/2 BPS, and hence degenerate at zero temperature due to supersymmetry. This degeneracy is resolved, however, at finite temperature, and we identify the configuration that gives the smallest free energy at each temperature. The Hagedorn transition in each vacuum is studied by using the eigenvalue density method for the gauge field moduli, and the free energy as well as the Polyakov line is obtained analytically near the critical point. This reveals the existence of fuzzy sphere phases, which may correspond to the plasma-ball phases in N=4 SU(\\infty) SYM on S^1 X S^3. We also perform Monte Carlo simulation to integrate over the gauge field moduli. While this confirms the validity of the analytic results near the critical point, it also shows that the trivial vacuum gives the smallest free energy throughout the high temperature regime.

Naoyuki Kawahara; Jun Nishimura; Kentaroh Yoshida

2006-04-25T23:59:59.000Z

444

SciTech Connect: Comparison of the Dynamic Wake Meandering Model...  

Office of Scientific and Technical Information (OSTI)

Technologies Office Country of Publication: United States Language: English Subject: 17 WIND ENERGY WIND PLANT AERODYNAMICS; DYNAMIC WAKE MEANDERING; LARGE-EDDY SIMULATION; Wind...

445

A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras...  

Open Energy Info (EERE)

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...

446

Development of a Computational Fluid Dynamics Model for Combustion of Fast Pyrolysis Liquid (Bio-oil).  

E-Print Network [OSTI]

??A study was carried out into the computational fluid dynamic simulation of bio-oil combustion. Measurements were taken in an empirical burner to obtain information regarding… (more)

McGrath, Arran Thomas

2011-01-01T23:59:59.000Z

447

Integrating high-precision U-Pb geochronologic data with dynamic models of earth processes  

E-Print Network [OSTI]

Radioisotopic dating can provide critical constraints for understanding the rates of tectonic, dynamic and biologic processes operating on our planet. Improving the interpretation and implementation of geochronologic data ...

Blackburn, Terrence (Terrence Joseph)

2012-01-01T23:59:59.000Z

448

Development of a sub-scale dynamics model for pressure relaxation of multi-material cells in Lagrangian hydrodynamics  

SciTech Connect (OSTI)

We have extended the Sub-Scale Dynamics (SSD) closure model for multi-fluid computational cells. Volume exchange between two materials is based on the interface area and a notional interface translation velocity, which is derived from a linearized Riemann solution. We have extended the model to cells with any number of materials, computing pressure-difference-driven volume and energy exchange as the algebraic sum of pairwise interactions. In multiple dimensions, we rely on interface reconstruction to provide interface areas and orientations, and centroids of material polygons. In order to prevent unphysically large or unmanageably small material volumes, we have used a flux-corrected transport (FCT) approach to limit the pressure-driven part of the volume exchange. We describe the implementation of this model in two dimensions in the FLAG hydrodynamics code. We also report on Lagrangian test calculations, comparing them with others made using a mixed-zone closure model due to Tipton, and with corresponding calculations made with only single-material cells. We find that in some cases, the SSD model more accurately predicts the state of material in mixed cells. By comparing the algebraic forms of both models, we identify similar dependencies on state and dynamical variables, and propose explanations for the apparent higher fidelity of the SSD model.

Harrison, Alan K [Los Alamos National Laboratory; Shashkov, Mikhail J [Los Alamos National Laboratory; Fung, Jimmy [Los Alamos National Laboratory; Canfield, Thomas R [Los Alamos National Laboratory; Kamm, James R [SNLA

2010-10-14T23:59:59.000Z

449

Modeling Long-Term Landscape Dynamics and the Emergence of Intensification  

E-Print Network [OSTI]

interactions between agricultural practices and landscape change for the Mediterranean Basin. Here, we report the recursive interactions between social landuse decisions, climate change, and landscape dynamics at regional scales. The Mediterranean Landscape Dynamics project, along with a handful of other ongoing projects

450

Dynamics of interacting dark energy model in Einstein and Loop Quantum Cosmology  

E-Print Network [OSTI]

We investigate the background dynamics when dark energy is coupled to dark matter in the universe described by Einstein cosmology and Loop Quantum Cosmology. We introduce a new general form of dark sector coupling, which presents us a more complicated dynamical phase space. Differences in the phase space in obtaining the accelerated scaling attractor in Einstein cosmology and Loop Quantum Cosmology are disclosed.

Songbai Chen; Bin Wang; Jiliang Jing

2008-11-10T23:59:59.000Z

451

Cybersecurity Dynamics Shouhuai Xu  

E-Print Network [OSTI]

Cybersecurity Dynamics Shouhuai Xu Department of Computer Science, University of Texas at San Antonio ABSTRACT We explore the emerging field of Cybersecurity Dynamics, a candidate foundation for the Science of Cybersecurity. Keywords Cybersecurity dynamics, security model, security analysis 1

Xu, Shouhuai

452

An integral-balance nonlinear model to simulate changes in soil moisture, groundwater and surface runoff dynamics at the hillslope scale  

E-Print Network [OSTI]

An integral-balance nonlinear model to simulate changes in soil moisture, groundwater and surface-state integral-balance model for soil moisture and groundwater dynamics. Development of the model was motivated. Ã? 2014 Elsevier Ltd. All rights reserved. 1. Introduction Recent studies on the modeling

Jay, Laurent O.

453

Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system  

E-Print Network [OSTI]

DEALING WITH “BIG CIRCULATION FLOW RATE, SMALL TEMPERATURE DIFFERENCE” BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai...) Co.,Ltd, Anshan, China ABSTRACT Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal...

Zhong, L.

2014-01-01T23:59:59.000Z

454

Dynamic Modeling and Control of Nuclear Reactors Coupled to Closed-Loop Brayton Cycle Systems using SIMULINK{sup TM}  

SciTech Connect (OSTI)

The operation of space reactors for both in-space and planetary operations will require unprecedented levels of autonomy and control. Development of these autonomous control systems will require dynamic system models, effective control methodologies, and autonomous control logic. This paper briefly describes the results of reactor, power-conversion, and control models that are implemented in SIMULINK{sup TM} (Simulink, 2004). SIMULINK{sup TM} is a development environment packaged with MatLab{sup TM} (MatLab, 2004) that allows the creation of dynamic state flow models. Simulation modules for liquid metal, gas cooled reactors, and electrically heated systems have been developed, as have modules for dynamic power-conversion components such as, ducting, heat exchangers, turbines, compressors, permanent magnet alternators, and load resistors. Various control modules for the reactor and the power-conversion shaft speed have also been developed and simulated. The modules are compiled into libraries and can be easily connected in different ways to explore the operational space of a number of potential reactor, power-conversion system configurations, and control approaches. The modularity and variability of these SIMULINK{sup TM} models provides a way to simulate a variety of complete power generation systems. To date, both Liquid Metal Reactors (LMR), Gas Cooled Reactors (GCR), and electric heaters that are coupled to gas-dynamics systems and thermoelectric systems have been simulated and are used to understand the behavior of these systems. Current efforts are focused on improving the fidelity of the existing SIMULINK{sup TM} modules, extending them to include isotopic heaters, heat pipes, Stirling engines, and on developing state flow logic to provide intelligent autonomy. The simulation code is called RPC-SIM (Reactor Power and Control-Simulator)

Wright, Steven A.; Sanchez, Travis [Sandia National Laboratories, Org 6872 MS-1146, PO Box 5800 Albuquerque, New Mexico 87185 (United States)

2005-02-06T23:59:59.000Z

455

Compartment modeling of dynamic brain PET—The impact of scatter corrections on parameter errors  

SciTech Connect (OSTI)

Purpose: The aim of this study was to investigate the effect of scatter and its correction on kinetic parameters in dynamic brain positron emission tomography (PET) tumor imaging. The 2-tissue compartment model was used, and two different reconstruction methods and two scatter correction (SC) schemes were investigated. Methods: The GATE Monte Carlo (MC) software was used to perform 2 × 15 full PET scan simulations of a voxelized head phantom with inserted tumor regions. The two sets of kinetic parameters of all tissues were chosen to represent the 2-tissue compartment model for the tracer 3?-deoxy-3?-({sup 18}F)fluorothymidine (FLT), and were denoted FLT{sub 1} and FLT{sub 2}. PET data were reconstructed with both 3D filtered back-projection with reprojection (3DRP) and 3D ordered-subset expectation maximization (OSEM). Images including true coincidences with attenuation correction (AC) and true+scattered coincidences with AC and with and without one of two applied SC schemes were reconstructed. Kinetic parameters were estimated by weighted nonlinear least squares fitting of image derived time–activity curves. Calculated parameters were compared to the true input to the MC simulations. Results: The relative parameter biases for scatter-eliminated data were 15%, 16%, 4%, 30%, 9%, and 7% (FLT{sub 1}) and 13%, 6%, 1%, 46%, 12%, and 8% (FLT{sub 2}) for K{sub 1}, k{sub 2}, k{sub 3}, k{sub 4}, V{sub a}, and K{sub i}, respectively. As expected, SC was essential for most parameters since omitting it increased biases by 10 percentage points on average. SC was not found necessary for the estimation of K{sub i} and k{sub 3}, however. There was no significant difference in parameter biases between the two investigated SC schemes or from parameter biases from scatter-eliminated PET data. Furthermore, neither 3DRP nor OSEM yielded the smallest parameter biases consistently although there was a slight favor for 3DRP which produced less biased k{sub 3} and K{sub i} estimates while OSEM resulted in a less biased V{sub a}. The uncertainty in OSEM parameters was about 26% (FLT{sub 1}) and 12% (FLT{sub 2}) larger than for 3DRP although identical postfilters were applied. Conclusions: SC was important for good parameter estimations. Both investigated SC schemes performed equally well on average and properly corrected for the scattered radiation, without introducing further bias. Furthermore, 3DRP was slightly favorable over OSEM in terms of kinetic parameter biases and SDs.

Häggström, Ida, E-mail: ida.haggstrom@radfys.umu.se; Karlsson, Mikael; Larsson, Anne [Department of Radiation Sciences, Umeå University, Umeå 90187 (Sweden); Schmidtlein, C. Ross [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York 10065 (United States)

2014-11-01T23:59:59.000Z

456

Nonminimal Macroscopic Models of a Scalar Field Based on Microscopic Dynamics. I. Extension of the Theory for Negative Masses  

E-Print Network [OSTI]

The article proposes generalizations of the macroscopic model of plasma of scalar charged particles to the cases of inter-particle interaction with multiple scalar fields and negative effective masses of these particles. The model is based on the microscopic dynamics of a particle at presence of scalar fields. The theory is managed to be generalized naturally having strictly reviewed a series of its key positions depending on the sign of particle masses. Thereby, it is possible to remove the artiicial restriction contradicting the more fundamental principle of action functional additivity.

Ignat'ev, Yu G

2015-01-01T23:59:59.000Z

457

Avalanche dynamics in model two-dimensional grain piles Surajit Sen1  

E-Print Network [OSTI]

The dynamical behavior of dry granular materials such as sand, gravel, salt, and the like have fascinated in significant progress in the understand- ing of the packing of granular materials and in describing flowing

Sen, Surajit

458

Using the FLUENT computational fluid dynamics code to model the NACOK corrosion test  

E-Print Network [OSTI]

As a part of advancing nuclear technology, computational fluid dynamics (CFD) analysis offers safer and lower-cost results relative to experimental work. Its use as a safety analysis tool is gaining much broader acceptance ...

Parks, Benjamin T

2004-01-01T23:59:59.000Z

459

Flowness + FlowBlocks : uncovering the dynamics of everyday life through playful modeling  

E-Print Network [OSTI]

It is not easy to understand the dynamics underlying everyday life. The change around us is so ubiquitous; the processes governing change are invisible; the relationships between cause & effect are usually disconnected in ...

Zuckerman, Oren, 1970-

2007-01-01T23:59:59.000Z

460

Structure and dynamics of model colloidal clusters with short-range attractions  

E-Print Network [OSTI]

We examine the structure and dynamics of small isolated $N$-particle clusters interacting via short-ranged Morse potentials. "Ideally preprared ensembles" obtained via exact enumeration studies of sticky hard sphere packings serve as reference states allowing us to identify key statistical-geometrical properties and to quantitatively characterize how nonequilibrium ensembles prepared by thermal quenches at different rates $\\dot{T}$ differ from their equilibrium counterparts. Studies of equilibrium dynamics show nontrival temperature dependence: nonexponential relaxation indicates both glassy dynamics and differing stabilities of degenerate clusters with different structures. Our results should be useful for extending recent experimental studies of small colloidal clusters to examine both equilibrium relaxation dynamics at fixed $T$ and a variety of nonequilibrium phenomena.

Robert S. Hoy

2015-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "dynamics model redyn" 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

Modeling the resource consumption of Housing in New Orleans using System Dynamics  

E-Print Network [OSTI]

This work uses Systems Dynamics as a methodology to analyze the resource requirements of New Orleans as it recovers from Hurricane Katrina. It examines the behavior of the city as a system of stocks, flows and time delays ...

Quinn, David James, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

462

Model-Based Methodology for Building Confidence in a Dynamic Measuring System  

E-Print Network [OSTI]

This thesis examines the special case in which a newly developed dynamic measurement system must be characterized when an accepted standard qualification procedure does not yet exist. In order to characterize this type of system, both physical...

Reese, Isaac Mark

2013-05-03T23:59:59.000Z

463

Incorporating endogenous demand dynamics into long-term capacity expansion power system models for Developing countries  

E-Print Network [OSTI]

This research develops a novel approach to long-term power system capacity expansion planning for developing countries by incorporating endogenous demand dynamics resulting from social processes of technology adoption. ...

Jordan, Rhonda LeNai

2013-01-01T23:59:59.000Z

464

Short communication Dynamics of a model of two delay-coupled relaxation oscillators  

E-Print Network [OSTI]

: Coupled oscillators Devil's Staircase Delay-differential equations a b s t r a c t This paper investigates by regions of complicated dynamics, reminiscent of the Devil's Staircase. Stability of motions in the in

Rand, Richard H.

465

Final Technical Report for "Collaborative Research: Regional climate-change projections through next-generation empirical and dynamical models"  

SciTech Connect (OSTI)

This project was a continuation of previous work under DOE CCPP funding in which we developed a twin approach of non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. We have developed a family of latent-variable NHMMs to simulate historical records of daily rainfall, and used them to downscale seasonal predictions. We have also developed empirical mode reduction (EMR) models for gaining insight into the underlying dynamics in observational data and general circulation model (GCM) simulations. Using coupled O-A ICMs, we have identified a new mechanism of interdecadal climate variability, involving the midlatitude oceans mesoscale eddy field and nonlinear, persistent atmospheric response to the oceanic anomalies. A related decadal mode is also identified, associated with the oceans thermohaline circulation. The goal of the continuation was to build on these ICM results and NHMM/EMR model developments and software to strengthen two key pillars of support for the development and application of climate models for climate change projections on time scales of decades to centuries, namely: (a) dynamical and theoretical understanding of decadal-to-interdecadal oscillations and their predictability; and (b) an interface from climate models to applications, in order to inform societal adaptation strategies to climate change at the regional scale, including model calibration, correction, downscaling and, most importantly, assessment and interpretation of spread and uncertainties in multi-model ensembles. Our main results from the grant consist of extensive further development of the hidden Markov models for rainfall simulation and downscaling specifically within the non-stationary climate change context together with the development of parallelized software; application of NHMMs to downscaling of rainfall projections over India; identification and analysis of decadal climate signals in data and models; and, studies of climate variability in terms of the dynamics of atmospheric flow regimes. Each of these project components is elaborated on below, followed by a list of publications resulting from the grant.

Robertson, A.W.; Ghil, M.; Kravtsov, K.; Smyth, P.J.

2011-04-08T23:59:59.000Z

466

Final Technical Report for "Collaborative Research: Regional climate-change projections through next-generation empirical and dynamical models"  

SciTech Connect (OSTI)

This project was a continuation of previous work under DOE CCPP funding in which we developed a twin approach of non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. We have developed a family of latent-variable NHMMs to simulate historical records of daily rainfall, and used them to downscale seasonal predictions. We have also developed empirical mode reduction (EMR) models for gaining insight into the underlying dynamics in observational data and general circulation model (GCM) simulations. Using coupled O-A ICMs, we have identified a new mechanism of interdecadal climate variability, involving the midlatitude oceansâ?? mesoscale eddy field and nonlinear, persistent atmospheric response to the oceanic anomalies. A related decadal mode is also identified, associated with the oceansâ?? thermohaline circulation. The goal of the continuation was to build on these ICM results and NHMM/EMR model developments and software to strengthen two key pillars of support for the development and application of climate models for climate change projections on time scales of decades to centuries, namely: (a) dynamical and theoretical understanding of decadal-to-interdecadal oscillations and their predictability; and (b) an interface from climate models to applications, in order to inform societal adaptation strategies to climate change at the regional scale, including model calibration, correction, downscaling and, most importantly, assessment and interpretation of spread and uncertainties in multi-model ensembles. Our main results from the grant consist of extensive further development of the hidden Markov models for rainfall simulation and downscaling specifically within the non-stationary climate change context together with the development of parallelized software; application of NHMMs to downscaling of rainfall projections over India; identification and analysis of decadal climate signals in data and models; and, studies of climate variability in terms of the dynamics of atmospheric flow regimes. Each of these project components is elaborated on below, followed by a list of publications resulting from the grant.

Kravtsov, S.; Robertson, A. W.; Ghil, M.; Smyth, P. J.

2011-04-08T23:59:59.000Z

467

Modeling oscillatory dynamics in brain microcircuits as a way to help uncover neurological disease mechanisms: A proposal  

SciTech Connect (OSTI)

There is an undisputed need and requirement for theoretical and computational studies in Neuroscience today. Furthermore, it is clear that oscillatory dynamical output from brain networks is representative of various behavioural states, and it is becoming clear that one could consider these outputs as measures of normal and pathological brain states. Although mathematical modeling of oscillatory dynamics in the context of neurological disease exists, it is a highly challenging endeavour because of the many levels of organization in the nervous system. This challenge is coupled with the increasing knowledge of cellular specificity and network dysfunction that is associated with disease. Recently, whole hippocampus in vitro preparations from control animals have been shown to spontaneously express oscillatory activities. In addition, when using preparations derived from animal models of disease, these activities show particular alterations. These preparations present an opportunity to address challenges involved with using models to gain insight because of easier access to simultaneous cellular and network measurements, and pharmacological modulations. We propose that by developing and using models with direct links to experiment at multiple levels, which at least include cellular and microcircuit, a cycling can be set up and used to help us determine critical mechanisms underlying neurological disease. We illustrate our proposal using our previously developed inhibitory network models in the context of these whole hippocampus preparations and show the importance of having direct links at multiple levels.

Skinner, F. K. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada) [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Medicine (Neurology), University of Toronto, 200 Elizabeth Street, Toronto, Ontario M5G 2C4 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8 (Canada); Ferguson, K. A. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada) [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8 (Canada)

2013-12-15T23:59:59.000Z

468

Comparison of four models simulating phosphorus dynamics in LakeVnern,Sweden Hydrology and Earth System Sciences, 8(6), 11531163 (2004) EGU  

E-Print Network [OSTI]

Comparison of four models simulating phosphorus dynamics in LakeVänern,Sweden 1153 Hydrology dynamics in Lake Vänern, Sweden Magnus Dahl1 and B. Charlotta Pers2 1 Department of Chemical Engineering, Karlstad University, SE651 88 Karlstad, Sweden 2 Swedish Meteorological and Hydrological Institute, SE601

Paris-Sud XI, Université de

469

A Dynamic Model for Wave-Induced Light Fluctuations in a Kelp Forest Author(s): Stephen R. Wing, James J. Leichter, Mark W. Denny  

E-Print Network [OSTI]

A Dynamic Model for Wave-Induced Light Fluctuations in a Kelp Forest Author(s): Stephen R. Wing forestsand marine kelp forests (Pearcy 1990; Gerard 1984), and theirphoton Acknowledgments We acknowledgethe

Denny, Mark

470

International Snow Science Workshop Grenoble Chamonix Mont-Blanc -2013 Why don't avalanche-dynamics models of higher complexity necessarily  

E-Print Network [OSTI]

-dynamics models of higher complexity necessarily lead to better predictions? Christophe Ancey École Polytechnique worldwide. Paradoxically, the substantial increase in model complexity can lead us to lose sight of the empirical nature of the assumptions used to build the models. Human expertise should still be of paramount

Lenstra, Arjen K.

471

Progressive Dynamical Drive Train Modeling as Part of NREL Gearbox Reliability Collaborative: Preprint  

SciTech Connect (OSTI)

The Gearbox Reliabiity Collaborative seeks to integrate several numerical models into the wind turbine drive train design process. This paper describes these models.

Oyague, F.

2008-07-01T23:59:59.000Z

472

Back-action effects in an all-optical model of dynamical Casimir emission  

E-Print Network [OSTI]

We report a theoretical study of the optical properties of a three-level emitter embedded in an optical cavity including the non-rotating wave terms of the light-matter interaction Hamiltonian. Rabi oscillations induced by a continuous wave drive laser are responsible for a periodic time-modulation of the effective cavity resonance, which results in a significant dynamical Casimir emission. A clear signature of the back-action effect of the dynamical Casimir emission onto the drive laser is visible as a sizable suppression of its absorption.

I. Carusotto; S. De Liberato; D. Gerace; C. Ciuti

2011-07-03T23:59:59.000Z

473

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

SciTech Connect (OSTI)

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

Wan, Y. H.

2013-01-01T23:59:59.000Z

474

Climate-Soil-Vegetation Control on Groundwater Table Dynamics and its Feedbacks in a Climate Model  

SciTech Connect (OSTI)

Among the three dynamically linked branches of the water cycle, including atmospheric, surface, and subsurface water, groundwater is the largest reservoir and an active component of the hydrologic system. Because of the inherent slow response time, groundwater may be particularly relevant for long time-scale processes such as multi-years or decadal droughts. This study uses regional climate simulations with and without surface water – groundwater interactions for the conterminous U.S. to assess the influence of climate, soil, and vegetation on groundwater table dynamics, and its potential feedbacks to regional climate. Analysis shows that precipitation has a dominant influence on the spatial and temporal variations of groundwater table depth (GWT). The simulated GWT is found to decrease sharply with increasing precipitation. Our simulation also shows some distinct spatial variations that are related to soil porosity and hydraulic conductivity. Vegetation properties such as minimum stomatal resistance, and root depth and fraction are also found to play an important role in controlling the groundwater table. Comparing two simulations with and without groundwater table dynamics, we find that groundwater table dynamics mainly influences the partitioning of soil water between the surface (0 – 0.5 m) and subsurface (0.5 – 5 m) rather than total soil moisture. In most areas, groundwater table dynamics increases surface soil moisture at the expense of the subsurface, except in regions with very shallow groundwater table. The change in soil water partitioning between the surface and subsurface is found to strongly correlate with the partitioning of surface sensible and latent heat fluxes. The evaporative fraction (EF) is generally higher during summer when groundwater table dynamics is included. This is accompanied by increased cloudiness, reduced diurnal temperature range, cooler surface temperature, and increased cloud top height. Although both convective and non-convective precipitation are enhanced, the higher EF changes the partitioning to favor more non-convective precipitation, but this result could be sensitive to the convective parameterization used. Compared to simulations without groundwater table dynamics, the dry bias in the summer precipitation is slightly reduced over the central and eastern U.S. Groundwater table dynamics can provide important feedbacks to atmospheric processes, and these feedbacks are stronger in regions with deeper groundwater table, because the interactions between surface and subsurface are weak when the groundwater table is deep. This increases the sensitivity of surface soil moisture to precipitation anomalies, and therefore enhances land surface feedbacks to the atmosphere through changes in soil moisture and evaporative fraction. By altering the groundwater table depth, land use change and groundwater withdrawal can alter land surface response and feedback to the climate system.

Leung, Lai-Yung R.; Huang, Maoyi; Qian, Yun; Liang, Xu

2010-01-29T23:59:59.000Z

475

USING BOX-JENKINS MODELS TO FORECAST FISHERY DYNAMICS: IDENTIFICATION, ESTIMATION, AND CHECKING  

E-Print Network [OSTI]

~ is illustrated by developing a model that makes monthly forecasts of skipjack tuna, Katsuwonus pelamis, catches

476

New perspectives in fluid dynamics: Mathematical analysis of a model proposed by  

E-Print Network [OSTI]

thermophoretic and diffusiophoretic experimental data (see [3]). At the level of mathematical modeling, Brenner

Vasseur, Alexis

477

Building design and thermal renovation measures proposal by means of regression models issued from dynamic simulations  

E-Print Network [OSTI]

comparison between different energy reduction strategies, like improving the insulation levels or increasing the thermal inertia. An example of their use and a data comparison with a dynamic simulation is shown in last;Nowadays, the most reliable solutions to calculate the energy demand are the simulation energy tools

Boyer, Edmond

478

Dynamical Models Explaining Social Balance and Evolution of Cooperation V.A. Traag,1  

E-Print Network [OSTI]

are bal- anced. Such a balanced network can be split into (at most) two opposing factions with posi- tive links within a faction and negative links be- tween them.3 Although inherently dynamical, the theory has Unbalanced Two Factions FIG. 1. Social Balance. The two upper triads are balanced, while the two lower triads

De Leenheer, Patrick

479

Dynamics of Synoptic Eddy and Low-Frequency Flow Interaction. Part III: Baroclinic Model Results  

E-Print Network [OSTI]

of Environmental Earth Science, Hokkaido University, Sapporo, Japan (Manuscript received 18 April 2005, in final an important role in generating the leading low-frequency modes in the extratropical circulation anomalies the leading modes equivalent barotropic. Through singular vector analysis of the linear dynamical operator

Wang, Yuqing

480

A Dynamic Network Economic Model of a Service-Oriented Internet with Price and  

E-Print Network [OSTI]

Anna Nagurney, Dong Li, Sara Saberi, Tilman Wolf Abstract In this paper, we develop a dynamic network-mail: dongl@som.umass.edu Sara Saberi Department of Operations and Information Management, Isenberg School- sachusetts 01003, e-mail: wolf@ecs.umass.edu 1 #12;2 Anna Nagurney, Dong Li, Sara Saberi, Tilman Wolf 1

Nagurney, Anna

Note: This page contains sample records for the topic "dynamics model redyn" 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

Theoretical Population Biology 71 (2007) 111 Nonlinear dynamics and pattern bifurcations in a model for vegetation  

E-Print Network [OSTI]

Theoretical Population Biology 71 (2007) 1­11 Nonlinear dynamics and pattern bifurcations observed in aerial photographs of sub- Saharan Africa in the 1950s (MacFadyen, 1950; Hemming, 1965; Wickens in the plant density U because the presence of plant roots in the soil increases water ARTICLE IN PRESS www

Sherratt, Jonathan A.

482

Full vehicle dynamics model of a formula SAE racecar using ADAMS/Car  

E-Print Network [OSTI]

The Texas A&M University Formula SAE program currently has no rigorous method for analyzing or predicting the overall dynamic behavior of the student-designed racecars. The objective of this study is to fulfill this need by creating a full vehicle...

Mueller, Russell Lee

2005-11-01T23:59:59.000Z

483

A Competitive and Dynamic Pricing Model for Secondary Users in Infrastructure based Networks  

E-Print Network [OSTI]

to the Wireless Service Providers (WSPs) for achieving efficient radio spectrum usage as well as gain additional dynamically with the changing radio spectrum usage at the BS. Assuming high competition among regional WSPs (WSPs) in acquiring the licensed spectrum, have a serious impact on the bottom line of the WSPs

Yanikomeroglu, Halim

484

Modeling and Dynamic Management of 3D Multicore Systems with Liquid Cooling  

E-Print Network [OSTI]

in the future to address the increasing power density. Considering the high power densities in 3D systems Mi- crosystems, UC MICRO, Center for Networked Systems (CNS) at UCSD, MARCO/DARPA GSRC and NSFModeling and Dynamic Management of 3D Multicore Systems with Liquid Cooling Ayse K. Coskun , Jos

Simunic, Tajana

485

Dynamic Modeling of Aerobic Growth of Shewanella oneidensis. Predicting Triauxic Growth, Flux Distributions and Energy Requirement for Growth  

SciTech Connect (OSTI)

A model-based analysis is conducted to investigate metabolism of Shewanella oneidensis MR-1 strain in aerobic batch culture, which exhibits an intriguing growth pattern by sequentially consuming substrate (i.e., lactate) and by-products (i.e., pyruvate and acetate). A general protocol is presented for developing a detailed network-based dynamic model for S. oneidensis based on the Lumped Hybrid Cybernetic Model (LHCM) framework. The L-HCM, although developed from only limited data, is shown to accurately reproduce exacting dynamic metabolic shifts, and provide reasonable estimates of energy requirement for growth. Flux distributions in S. oneidensis predicted by the L-HCM compare very favorably with 13C-metabolic flux analysis results reported in the literature. Predictive accuracy is enhanced by incorporating measurements of only a few intracellular fluxes, in addition to extracellular metabolites. The L-HCM developed here for S. oneidensis is consequently a promising tool for the analysis of intracellular flux distribution and metabolic engineering.

Song, Hyun-Seob; Ramkrishna, Doraiswami; Pinchuk, Grigoriy E.; Beliaev, Alex S.; Konopka, Allan; Fredrickson, Jim K.

2013-01-01T23:59:59.000Z

486

The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method  

E-Print Network [OSTI]

We study the dynamics of the giant elliptical galaxy M87 from the central to the outermost regions with the made-to-measure (M2M) method. We use a new catalogue of 922 globular cluster line-of- sight velocities extending to a projected radius of 180 kpc (equivalent to 25 M87 effective radii), and SAURON integral field unit data within the central 2.4 kpc. 263 globular clusters, mainly located beyond 40 kpc, are newly observed by the Next Generation Virgo Survey (NGVS). For the M2M modelling, the gravitational potential is taken as a combination of a luminous matter potential with a constant stellar mass-to-light ratio and a dark matter potential modelled as a logarithmic potential. Our best dynamical model returns a stellar mass-to-light ratio in the I band of M/LI = 6.0(+ -0.3) M_sun/L_sun with a dark matter potential scale velocity of 591(+ -50) km/s and scale radius of 42(+ -10) kpc. We determine the total mass of M87 within 180 kpc to be (1.5 + - 0.2) 10^13 M_sun. The mass within 40 kpc is smaller than pr...

Zhu, Ling; Mao, Shude; Peng, Eric W; Liu, Chengze; Caldwell, Nelson; Li, Biao; Blakeslee, John P; Cote, Patrick; Cuillandre, Jean-Charles; Durrell, Patrick; Emsellem, Eric; Ferrarese, Laura; Gwyn, Stephen; Jordan, Andres; Lancon, Ariane; Mei, Simona; Munoz, Roberto; Puzi, Thomas

2014-01-01T23:59:59.000Z

487

Holographic Dark Energy Models and Higher Order Generalizations in Dynamical Chern-Simons Modified Gravity  

E-Print Network [OSTI]

Dark Energy models are here investigated and studied in the framework of the Chern-Simons modified gravity model. We bring into focus the Holographic Dark Energy (HDE) model with Granda-Oliveros cut-off, the Modified Holographic Ricci Dark Energy (MHRDE) model and, moreover, a model with higher derivatives of the Hubble parameter as well. The relevant expressions of the scale factor a(t) for a Friedmann-Robertson-Walker Universe are derived and studied, and in this context, the evolution of the scale factor is shown to be similar to that one displayed by the modified Chaplygin gas in two of the above models.

Antonio Pasqua; Roldao da Rocha; Surajit Chattopadhyay

2014-12-29T23:59:59.000Z

488

Heating dynamics of CO{sub 2}-laser irradiated silica particles with evaporative shrinking: Measurements and modeling  

SciTech Connect (OSTI)

The heating dynamics of CO{sub 2}-laser heated micron-sized particles were determined for temperatures <3500 K measured using infrared imaging. A coupled mass and energy conservation model is derived to predict single particle temperatures and sizes, which were compared with data from particles deposited on non-absorbing substrates to assess the relevant heat transfer processes. Analysis reveals substrate conduction dominates all other heat losses, while laser absorption determined from Mie theory is strongly modulated by particle evaporative shrinking. This study provides insights into the light coupling and heating of particle arrays where the material optical properties are temperature-dependent and particle size changes are significant.

Elhadj, S.; Qiu, S. R.; Stolz, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Monterrosa, A. M. [Department of Nuclear Engineering and Department of Materials Science and Engineering, University of California, Berkeley, California 94704 (United States)

2012-05-01T23:59:59.000Z

489

Power law relaxation and glassy dynamics in Lebwohl-Lasher model near isotropic-nematic phase transition  

E-Print Network [OSTI]

Orientational dynamics in a liquid crystalline system near the isotropic-nematic (I-N) phase transition is studied using Molecular Dynamics simulations of the well-known Lebwohl-Lasher (LL) model. As the I-N transition temperature is approached from the isotropic side, we find that the decay of the orientational time correlation functions (OTCF) slows down noticeably, giving rise to a power law decay at intermediate timescales. The angular velocity time correlation function also exhibits a rather pronounced power law decay near the I-N boundary. In the mean squared angular displacement at comparable timescales, we observe the emergence of a \\emph{subdiffusive regime} which is followed by a \\emph{superdiffusive regime} before the onset of the long-time diffusive behavior. We observe signature of dynamical heterogeneity through \\emph{pronounced non-Gaussian behavior in orientational motion} particularly at lower temperatures. This behavior closely resembles what is usually observed in supercooled liquids. We obtain the free energy as a function of orientational order parameter by the use of transition matrix Monte Carlo method. The free energy surface is flat for the system considered here and the barrier between isotropic and nematic phases is vanishingly small for this weakly first-order phase transition, hence allowing large scale, collective and correlated orientational density fluctuations. This might be responsible for the observed power law decay of the OTCFs.

Suman Chakrabarty; Dwaipayan Chakrabarti; Biman Bagchi

2006-03-14T23:59:59.000Z

490

Climate change uncertainty evaluation, impacts modelling and resilience of farm scale dynamics in Scotland   

E-Print Network [OSTI]

evidence of how primary production components of agriculture in Scotland may change under a future climate. The work used a generic Integrated Modelling Framework to structure the following sequence of investigations: Evaluate a Regional Climate Model...

Rivington, Michael

2011-06-28T23:59:59.000Z

491

Dynamic risk adjustment of prediction models using statistical process control methods  

E-Print Network [OSTI]

Introduction. Models that represent mathematical relationships between clinical outcomes and their predictors are useful to the decision making process in patient care. Many models, such as the score of neonatal physiology ...

Chuo, John, 1969-

2004-01-01T23:59:59.000Z

492

Transient Temperature Modeling For Wellbore Fluid Under Static and Dynamic Conditions  

E-Print Network [OSTI]

for geothermal wells and prediction of injection fluid temperatures. In this thesis, development and usage of three models for transient fluid temperature are presented. Two models predict transient temperature of flowing fluid under separate flow configurations...

Ali, Muhammad

2014-04-22T23:59:59.000Z

493

LA-UR-09-02185 Integrated System Dynamics Model to  

E-Print Network [OSTI]

Policy: PV Renewable Policy: wind Public Transp Policy Hybrid-cars Policy Mental model residential In this first version of the model, we considered two CO2 emissions sources Renewable Policy: wind Renewable

Keller, Arturo A.

494

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

E-Print Network [OSTI]

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

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

2010-01-01T23:59:59.000Z

495

Liquefied Natural Gas (LNG) Vapor Dispersion Modeling with Computational Fluid Dynamics Codes  

E-Print Network [OSTI]

Federal regulation 49 CFR 193 and standard NFPA 59A require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. For modeling purposes, the physical...

Qi, Ruifeng

2012-10-19T23:59:59.000Z

496

Dynamic Modeling and Wavelet-Based Multi-Parametric Tuning and Validation for HVAC Systems  

E-Print Network [OSTI]

. Tummescheit and Eborn [11] discussed the modeling of a thermo-hydraulic model using lumped parameter and distributed parameter methods using commercial software known as Modelica. In 2002, Bendapudi [12] presented a detailed literature review of notable...

Liang, Shuangshuang

2014-07-10T23:59:59.000Z

497

Non-smooth Dynamics Using Differential-algebraic Equations Perspective: Modeling and Numerical Solutions  

E-Print Network [OSTI]

mathematical tools. On the other hand, the approach based on differential-algebraic equations gives more insight into the constitutive assumptions of a chosen model and easier to obtain numerical solutions. Bingham-type models in which the force cannot...

Gotika, Priyanka

2012-02-14T23:59:59.000Z

498

Forest dynamics at regional scales: predictive models constrained with inventory data  

E-Print Network [OSTI]

by scaling from key tree-level processes, but models typically have no climate dependency. In this thesis I demonstrate how large-scale national inventories combined with improvements in computational methods mean that models that incorporate the climate...

Lines, Emily

2012-06-12T23:59:59.000Z

499

A trajectory piecewise-linear approach to model order reduction of nonlinear dynamical systems  

E-Print Network [OSTI]

(cont.) Finally, we present projection schemes which result in improved accuracy of the reduced order TPWL models, as well as discuss approaches leading to guaranteed stable and passive TPWL reduced-order mode