Assessing the reliability of linear dynamic transformer thermal modelling
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
Paris-Sud XI, Université de
Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application) Key Words: failure, damage, regeneration, availability assessment, stochastic activity networks, Monte Carlo simulations SUMMARY & CONCLUSIONS Availability is a determining factor in systems characterization
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations Characterizing and optimizing overall performance of wind plants composed of large numbers at the National Renewable Energy Laboratory (NREL) are coupling physical models of the atmosphere and wind
Dynamic nuclear renography kinetic analysis: Four-compartment model for assessing kidney function
Raswan, T. R., E-mail: tara.raissa@gmail.com; Haryanto, F., E-mail: tara.raissa@gmail.com [Department of Physics, Nuclear Physics and Biophysics Research Group, Institut Teknologi Bandung, Bandung (Indonesia)
2014-09-30T23:59:59.000Z
Dynamic nuclear renography method produces TACs of kidneys and bladder. Multiple TACs data can be further analyzed to obtain the overview of urinary system's condition. Tracer kinetic analysis was performed using four-compartment models. The system's model consist of four irreversible compartment with four transport constants (k1, k2, k3 and k4). The mathematical expressions of tracer's distributions is fitted to experimental data (TACs) resulting in model constants. This transport constants represent the urinary system behavior, and later can be used for analyzing system's condition. Different intervals of kinetics parameter are clearly shown by abnormal system with respect to the normal one. Furthermore, the system with delayed uptake has 82% lower uptake parameters (k1 and k2) than normal one. Meanwhile, the system with prolonged clearance time has its kinetics parameters k3 or k4 lower than the others. This model is promising for quantitatively describe urinary system's function especially if supplied with more data.
assessing dynamic magnetic: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
0 Assessment of Carotid Flow Using Magnetic Resonance Imaging and Computational Fluid Dynamics) direct, model-independent velocity mapping using flow-encoded magnetic resonance...
Benjamin, A.S.; Paez, T.L.; Brown, N.N.
1998-01-01T23:59:59.000Z
In most probabilistic risk assessments, there is a subset of accident scenarios that involves physical challenges to the system, such as high heat rates and/or accelerations. The system`s responses to these challenges may be complicated, and their prediction may require the use of long-running computer codes. To deal with the many scenarios demanded by a risk assessment, the authors have been investigating the use of artificial neural networks (ANNs) as a fast-running estimation tool. They have developed a multivariate linear spline algorithm by extending previous ANN methods that use radial basis functions. They have applied the algorithm to problems involving fires, shocks, and vibrations. They have found that within the parameter range for which it is trained, the algorithm can simulate the nonlinear responses of complex systems with high accuracy. Running times per case are less than one second.
Assessment of Models for Pedestrian Dynamics with Functional Principal Component Analysis
Chraibi, M; Gottschalk, H; Saadi, M; Seyfried, A
2015-01-01T23:59:59.000Z
Many agent based simulation approaches have been proposed for pedestrian flow. As such models are applied e.g.\\ in evacuation studies, the quality and reliability of such models is of vital interest. Pedestrian trajectories are functional data and thus functional principal component analysis is a natural tool to asses the quality of pedestrian flow models beyond average properties. In this article we conduct functional PCA for the trajectories of pedestrians passing through a bottleneck. We benchmark two agent based models of pedestrian flow against the experimental data using PCA average and stochastic features. Functional PCA proves to be an efficient tool to detect deviation between simulation and experiment and to asses quality of pedestrian models.
Queuing models System dynamics models
Glushko, Robert J.
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
Dynamic modeling of physical phenomena for probabilistic assessment of spent fuel accidents
Benjamin, A.S.
1997-11-01T23:59:59.000Z
If there should be an accident involving drainage of all the water from a spent fuel pool, the fuel elements will heat up until the heat produced by radioactive decay is balanced by that removed by natural convection to air, thermal radiation, and other means. If the temperatures become high enough for the cladding or other materials to ignite due to rapid oxidation, then some of the fuel might melt, leading to an undesirable release of radioactive materials. The amount of melting is dependent upon the fuel loading configuration and its age, the oxidation and melting characteristics of the materials, and the potential effectiveness of recovery actions. The authors have developed methods for modeling the pertinent physical phenomena and integrating the results with a probabilistic treatment of the uncertainty distributions. The net result is a set of complementary cumulative distribution functions for the amount of fuel melted.
Dynamical systems probabilistic risk assessment.
Denman, Matthew R.; Ames, Arlo Leroy
2014-03-01T23:59:59.000Z
Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.
Predictive Dynamic Security Assessment through Advanced Computing
Huang, Zhenyu; Diao, Ruisheng; Jin, Shuangshuang; Chen, Yousu
2014-11-30T23:59:59.000Z
Abstract— Traditional dynamic security assessment is limited by several factors and thus falls short in providing real-time information to be predictive for power system operation. These factors include the steady-state assumption of current operating points, static transfer limits, and low computational speed. This addresses these factors and frames predictive dynamic security assessment. The primary objective of predictive dynamic security assessment is to enhance the functionality and computational process of dynamic security assessment through the use of high-speed phasor measurements and the application of advanced computing technologies for faster-than-real-time simulation. This paper presents algorithms, computing platforms, and simulation frameworks that constitute the predictive dynamic security assessment capability. Examples of phasor application and fast computation for dynamic security assessment are included to demonstrate the feasibility and speed enhancement for real-time applications.
Research progress in dynamic security assessment
Not Available
1982-12-01T23:59:59.000Z
Areas discussed are power system modeling, state estimation, structure decomposition, state forecasting, clustering and security measure development. A detailed dynamic model of a multi-machine power system has been developed. A process state estimator was developed to estimate the long-term dynamic behavior of the power system. The algorithm is identical to the extended Kalman filter but has a modified process noise driving term. A two-stage structure estimation technique was proposed for identifying the power system network configuration. Two approaches to structure decomposition were investigated. A time-scale decomposition of the system equations, based on a singular perturbation approach, was evaluated using a detailed model of a generating system. Spatial decomposition was examined by applying an optimal network decomposition technique to a 39-bus test system. Stochastic approximation based approaches to estimator simplification were examined. Explicit expressions were obtained for the evolution of the first and second moments of the system state. Research into security measures proceeded in three directions. The first area involves viewing the security assessment problem as a hyperplane crossing problem for a stochastic process. The second approach examined the stability of an unforced linear system where the system coefficients are subject to future jumps. The third area of research has led to the formulation of a security measure suitable for on-line assessment of transient stability.
Integrated Assessment Modeling
Edmonds, James A.; Calvin, Katherine V.; Clarke, Leon E.; Janetos, Anthony C.; Kim, Son H.; Wise, Marshall A.; McJeon, Haewon C.
2012-10-31T23:59:59.000Z
This paper discusses the role of Integrated Assessment models (IAMs) in climate change research. IAMs are an interdisciplinary research platform, which constitutes a consistent scientific framework in which the large-scale interactions between human and natural Earth systems can be examined. In so doing, IAMs provide insights that would otherwise be unavailable from traditional single-discipline research. By providing a broader view of the issue, IAMs constitute an important tool for decision support. IAMs are also a home of human Earth system research and provide natural Earth system scientists information about the nature of human intervention in global biogeophysical and geochemical processes.
Modal aerosol dynamics modeling
Whitby, E.R.; McMurry, P.H.; Shankar, U.; Binkowski, F.S.
1991-02-01T23:59:59.000Z
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.
Chen, Zhe
In recent years, time-varying inhomogeneous point process models have been introduced for assessment of instantaneous heartbeat dynamics as well as specific cardiovascular control mechanisms and hemodynamics. Assessment ...
Tools for dynamic model development
Schaber, Spencer Daniel
2014-01-01T23:59:59.000Z
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 ...
Mesoscale ocean dynamics modeling
mHolm, D.; Alber, M.; Bayly, B.; Camassa, R.; Choi, W.; Cockburn, B.; Jones, D.; Lifschitz, A.; Margolin, L.; Marsden, L.; Nadiga, B.; Poje, A.; Smolarkiewicz, P. [Los Alamos National Lab., NM (United States); Levermore, D. [Arizona Univ., Tucson, AZ (United States)
1996-05-01T23:59:59.000Z
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The ocean is a very complex nonlinear system that exhibits turbulence on essentially all scales, multiple equilibria, and significant intrinsic variability. Modeling the ocean`s dynamics at mesoscales is of fundamental importance for long-time-scale climate predictions. A major goal of this project has been to coordinate, strengthen, and focus the efforts of applied mathematicians, computer scientists, computational physicists and engineers (at LANL and a consortium of Universities) in a joint effort addressing the issues in mesoscale ocean dynamics. The project combines expertise in the core competencies of high performance computing and theory of complex systems in a new way that has great potential for improving ocean models now running on the Connection Machines CM-200 and CM-5 and on the Cray T3D.
Next Generation On-Line Dynamic Security Assessment
Next Generation On-Line Dynamic Security Assessment Parts III and IV Final Project Report Power;Next Generation On-Line Dynamic Security Assessment Parts III and IV Final Project Report Parts III Research Center (PSERC) research project titled "Next Generation On-Line Dynamic Security Assessment
Development of a Dynamic DOE Calibration Model
Broader source: Energy.gov (indexed) [DOE]
cell characterization * Train and validate dynamic models * Apply models for system optimization Results * Dynamic emissions models have been developed (validation error on the...
Assessment of Molecular Modeling & Simulation
None
2002-01-03T23:59:59.000Z
This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.
Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model Output
Shi, Tao
Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model of aerosol optical depth across mainland Southeast Asia. We include a cross validation study to assess
Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment
Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.
2009-06-01T23:59:59.000Z
This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based on this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.
DYNAMIC MODELING FUEL PROCESSORS
Mease, Kenneth D.
turbine module (compressor and turbine sub-modules) Catalytic oxidizer Combustor module Heat exchanger, PEM, Gas Turbine General Model Assumptions · 1D process flow · Well-stirred within nodal volume · Slow reactants #12;Steam Reformation Occurs in Reformer and Fuel Cells Methane reformation reaction Water Gas
Trends in Ln(III) Sorption to Quartz Assessed by Molecular Dynamics...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Ln(III) Sorption to Quartz Assessed by Molecular Dynamics Simulations and Laser Induced Flourescence Studies. Trends in Ln(III) Sorption to Quartz Assessed by Molecular Dynamics...
Computational Fluid Dynamics Framework for Turbine Biological Performance Assessment
Richmond, Marshall C.; Serkowski, John A.; Carlson, Thomas J.; Ebner, Laurie L.; Sick, Mirjam; Cada, G. F.
2011-05-04T23:59:59.000Z
In this paper, a method for turbine biological performance assessment is introduced to bridge the gap between field and laboratory studies on fish injury and turbine design. Using this method, a suite of biological performance indicators is computed based on simulated data from a computational fluid dynamics (CFD) model of a proposed turbine design. Each performance indicator is a measure of the probability of exposure to a certain dose of an injury mechanism. If the relationship between the dose of an injury mechanism and frequency of injury (dose-response) is known from laboratory or field studies, the likelihood of fish injury for a turbine design can be computed from the performance indicator. By comparing the values of the indicators from various turbine designs, the engineer can identify the more-promising designs. Discussion here is focused on Kaplan-type turbines, although the method could be extended to other designs. Following the description of the general methodology, we will present sample risk assessment calculations based on CFD data from a model of the John Day Dam on the Columbia River in the USA.
An Impact Assessment Model for Distributed Adaptive Security Situation Assessment*
California at Davis, University of
1 An Impact Assessment Model for Distributed Adaptive Security Situation Assessment* Mark Heckman mechanism is not simply to stop attacks, but to protect a computing resource so that the resource can continue to perform its function. A computing resource, however, is only a component of a larger system
Chen, Zhe
In this article, we present a point process method to assess dynamic baroreflex sensitivity (BRS) by estimating the baroreflex gain as focal component of a simplified closed-loop model of the cardiovascular system. ...
A Relativistic Dynamical Collapse Model
Philip Pearle
2014-12-21T23:59:59.000Z
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 $\\Lambda= \\lambda/\\ell a^{2}$.
Bayesian inference of stochastic dynamical models
Lu, Peter Guang Yi
2013-01-01T23:59:59.000Z
A new methodology for Bayesian inference of stochastic dynamical models is developed. The methodology leverages the dynamically orthogonal (DO) evolution equations for reduced-dimension uncertainty evolution and the Gaussian ...
Dynamic Operational Risk Assessment with Bayesian Network
Barua, Shubharthi
2012-10-19T23:59:59.000Z
-spread acceptance in the oil and gas industry after the Piper Alpha disaster in 1988. The Lord Cullen investigation report (1990) on the Piper Alpha disaster recommended formulating quantitative risk assessment as an official requirement for the oil and gas... such as the Flixborough disaster, the Bhopal incident, and the Piper Alpha disaster caused fatalities and unbearable economic loss. The U.S. Chemical Safety Board (U.S. CSB, April 06, 2012) completed investigation on sixty-five serious accidents that occurred in the U...
DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.
Paris-Sud XI, UniversitÃ© de
(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
Dynamic control of DHM for ergonomic assessments Giovanni De Magistrisa,
Boyer, Edmond
Dynamic control of DHM for ergonomic assessments Giovanni De Magistrisa, , Alain Micaellia , Paul hamper movement task per- formance. In recent years, it has become possible to study the ergonomic ergonomic aspects, especially when it comes to movement, applied forces and joint torques evaluation
Assessment and Event Based Analysis of Dynamic Wireless Networks
Paris-Sud XI, Université de
Assessment and Event Based Analysis of Dynamic Wireless Networks Denis Carvin1,2, Guillaume Kremer1 of mobile nodes in networks is significantly changing the way they are managed. Indeed, these wireless-estimation algorithm for wireless mobile networks. We then provide events' collection and distributed mining methods
Modelling and Dynamic Simulation for Process Control
Skogestad, Sigurd
principles for model development are outlined, and these principles are applied to a simple ash tank (which. In this paper we consider dynamic process models obtained using fundamental principles (eg. based reactor, a simple trend analysis using temperature measurements may be suÆcient. Dynamic models
Quantitative Modeling of High Temperature Magnetization Dynamics
Zhang, Shufeng
2009-03-01T23:59:59.000Z
Final Technical Report Project title: Quantitative Modeling of High Temperature Magnetization Dynamics DOE/Office of Science Program Manager Contact: Dr. James Davenport
Conceptual aircraft dynamics from inverse aircraft modeling
Ziegler, Gregory E
1999-01-01T23:59:59.000Z
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...
Model Validation with Hybrid Dynamic Simulation
Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.
2006-06-18T23:59:59.000Z
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.
Modeling and simulation of consumer response to dynamic pricing.
Valenzuela, J.; Thimmapuram, P.; Kim, J (Decision and Information Sciences); (Auburn Univ.)
2012-08-01T23:59:59.000Z
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.
ORISE: Dose modeling and assessments
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
or state regulatory compliance requirements are being met during the decontamination and decommissioning of nuclear facilities. Dose modeling is an important step in the...
Benchmarking of Planning Models Using Recorded Dynamics
Huang, Zhenyu; Yang, Bo; Kosterev, Dmitry
2009-03-15T23:59:59.000Z
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.
Models and parameters for environmental radiological assessments
Miller, C W [ed.] [ed.
1984-01-01T23:59:59.000Z
This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base. (ACR)
Very Large System Dynamics Models - Lessons Learned
Jacob J. Jacobson; Leonard Malczynski
2008-10-01T23:59:59.000Z
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.
Dynamic model failure tests of dam structures Dalian University of Technology, Dalian 116024, China
Spencer Jr., B.F.
Dynamic model failure tests of dam structures Gao Lin Dalian University of Technology, Dalian failure tests of a number of concrete gravity dams, concrete arch dams and embankment dams have been index for the safety assessment of concrete dams and is predicted through dynamic model failure tests
Model and Analytic Processes for Export License Assessments
Thompson, Sandra E.; Whitney, Paul D.; Weimar, Mark R.; Wood, Thomas W.; Daly, Don S.; Brothers, Alan J.; Sanfilippo, Antonio P.; Cook, Diane; Holder, Larry
2011-09-29T23:59:59.000Z
This paper represents the Department of Energy Office of Nonproliferation Research and Development (NA-22) Simulations, Algorithms and Modeling (SAM) Program's first effort to identify and frame analytical methods and tools to aid export control professionals in effectively predicting proliferation intent; a complex, multi-step and multi-agency process. The report focuses on analytical modeling methodologies that alone, or combined, may improve the proliferation export control license approval process. It is a follow-up to an earlier paper describing information sources and environments related to international nuclear technology transfer. This report describes the decision criteria used to evaluate modeling techniques and tools to determine which approaches will be investigated during the final 2 years of the project. The report also details the motivation for why new modeling techniques and tools are needed. The analytical modeling methodologies will enable analysts to evaluate the information environment for relevance to detecting proliferation intent, with specific focus on assessing risks associated with transferring dual-use technologies. Dual-use technologies can be used in both weapons and commercial enterprises. A decision-framework was developed to evaluate which of the different analytical modeling methodologies would be most appropriate conditional on the uniqueness of the approach, data availability, laboratory capabilities, relevance to NA-22 and Office of Arms Control and Nonproliferation (NA-24) research needs and the impact if successful. Modeling methodologies were divided into whether they could help micro-level assessments (e.g., help improve individual license assessments) or macro-level assessment. Macro-level assessment focuses on suppliers, technology, consumers, economies, and proliferation context. Macro-level assessment technologies scored higher in the area of uniqueness because less work has been done at the macro level. An approach to developing testable hypotheses for the macro-level assessment methodologies is provided. The outcome of this works suggests that we should develop a Bayes Net for micro-level analysis and continue to focus on Bayes Net, System Dynamics and Economic Input/Output models for assessing macro-level problems. Simultaneously, we need to develop metrics for assessing intent in export control, including the risks and consequences associated with all aspects of export control.
ORISE: Dose modeling and assessments
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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE ProjectCrisis and Risk CommunicationOakDose modeling
OPTIMAL CONTROL WITH ADAPTIVE INTERNAL DYNAMICS MODELS
Vijayakumar, Sethu
. The optimal feedback control law for systems with non-linear dynamics and non-quadratic costs can be foundOPTIMAL CONTROL WITH ADAPTIVE INTERNAL DYNAMICS MODELS Djordje Mitrovic, Stefan Klanke, and Sethu, optimal control, adaptive control, robot simulation Abstract: Optimal feedback control has been proposed
Simple Dynamic Gasifier Model That Runs in Aspen Dynamics
Robinson, P.J.; Luyben, W.L. [Lehigh University, Bethlehem, PA (United States). Dept. of Chemical Engineering
2008-10-15T23:59:59.000Z
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.
Protein viscoelastic dynamics: a model system
Craig Fogle; Joseph Rudnick; David Jasnow
2015-02-02T23:59:59.000Z
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.
Model Validation with Hybrid Dynamic Simulation
Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.
2006-06-22T23:59:59.000Z
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.
Dynamical models with a general anisotropy profile
M. Baes; E. Van Hese
2007-05-28T23:59:59.000Z
Both numerical simulations and observational evidence indicate that the outer regions of galaxies and dark matter haloes are typically mildly to significantly radially anisotropic. The inner regions can be significantly non-isotropic, depending on the dynamical formation and evolution processes. In an attempt to break the lack of simple dynamical models that can reproduce this behaviour, we explore a technique to construct dynamical models with an arbitrary density and an arbitrary anisotropy profile. We outline a general construction method and propose a more practical approach based on a parameterized anisotropy profile. This approach consists of fitting the density of the model with a set of dynamical components, each of which have the same anisotropy profile. Using this approach we avoid the delicate fine-tuning difficulties other fitting techniques typically encounter when constructing radially anisotropic models. We present a model anisotropy profile that generalizes the Osipkov-Merritt profile, and that can represent any smooth monotonic anisotropy profile. Based on this model anisotropy profile, we construct a very general seven-parameter set of dynamical components for which the most important dynamical properties can be calculated analytically. We use the results to look for simple one-component dynamical models that generate simple potential-density pairs while still supporting a flexible anisotropy profile. We present families of Plummer and Hernquist models in which the anisotropy at small and large radii can be chosen as free parameters. We also generalize these two families to a three-parameter family that self-consistently generates the set of Veltmann potential-density pairs. (Abridged...)
Assessment of Algal Farm Designs Using a Dynamic Modular Approach
Abodeely, Jared [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology
2014-07-01T23:59:59.000Z
The notion of renewable energy provides an important mechanism for diversifying an energy portfolio, which ultimately would have numerous benefits including increased energy resilience, reduction of foreign energy supplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth, and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associated with algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the Algae Logistics Model (ALM) which helps to address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments of multiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tier were sub-selected and assessed using daily site-specific algae biomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass productivity and that integration of novel dewatering equipment, order of operations, and equipment scaling can also have significant impacts on economics.
Assessment of Algal Farm Designs using a Dynamic Modular Approach
Abodeely, Jared M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology
2014-07-01T23:59:59.000Z
The notion of renewable energy provides an importantmechanism for diversifying an energy portfolio,which ultimately would have numerous benefits including increased energy resilience, reduced reliance on foreign energysupplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth,and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associatedwith algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the development and application of the Algae Logistics Model (ALM) which is tailored to help address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments ofmultiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tierwere sub-selected and assessed using daily site-specific algaebiomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass productivity and that integration of novel dewatering equipment, order of operations, and equipment scaling can also have significant impacts on economics.
Consistent nonlinear dynamics: identifying model inadequacy
Patrick E. McSharry; Leonard A. Smith
2004-03-09T23:59:59.000Z
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.
Dynamic Modeling of Butterfly Subdivision Surfaces
Qin, Hong
on control vertices. This provides the user an intuitive and natural feeling that is produced while modeling manipulation of control points, whereas we provide interaction tools that directly manipulate the smooth limitDynamic Modeling of Butterfly Subdivision Surfaces Chhandomay Mandal, Hong Qin, Member, IEEE
Modeling dynamic swarms q Bernard Ghanem a,
Ahuja, Narendra
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
Modeling the Dynamics of Compromised Networks
Soper, B; Merl, D M
2011-09-12T23:59:59.000Z
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.
Dynamical System Analysis for a phantom model
Nilanjana Mahata; Subenoy Chakraborty
2014-04-24T23:59:59.000Z
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.
Dynamical dark matter. II. An explicit model
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dienes, Keith R.; Thomas, Brooks
2012-04-01T23:59:59.000Z
In a recent paper [K. R. Dienes and B. Thomas, Phys. Rev. D 85, 083523 (2012).], we introduced “dynamical dark matter,” a new framework for dark-matter physics, and outlined its underlying theoretical principles and phenomenological possibilities. Unlike most traditional approaches to the dark-matter problem which hypothesize the existence of one or more stable dark-matter particles, our dynamical dark-matter framework is characterized by the fact that the requirement of stability is replaced by a delicate balancing between cosmological abundances and lifetimes across a vast ensemble of individual dark-matter components. This setup therefore collectively produces a time-varying cosmological dark-matter abundance, and the different dark-matter components can interact and decay throughout the current epoch. While the goal of our previous paper was to introduce the broad theoretical aspects of this framework, the purpose of the current paper is to provide an explicit model of dynamical dark matter and demonstrate that this model satisfies all collider, astrophysical, and cosmological constraints. The results of this paper therefore constitute an “existence proof” of the phenomenological viability of our overall dynamical dark-matter framework, and demonstrate that dynamical dark matter is indeed a viable alternative to the traditional paradigm of dark-matter physics. Dynamical dark matter must therefore be considered alongside other approaches to the dark-matter problem, particularly in scenarios involving large extra dimensions or string theory in which there exist large numbers of particles which are neutral under standard-model symmetries.
Model assessment of protective barriers: Part 3
Fayer, M.J.; Rockhold, M.L.; Holford, D.J.
1992-02-01T23:59:59.000Z
Radioactive waste exists at the US Department of Energy's (DOE's) Hanford Site in a variety of locations, including subsurface grout and tank farms, solid waste burial grounds, and contaminated soil sites. Some of these waste sites may need to be isolated from percolating water to minimize the potential for transport of the waste to the ground water, which eventually discharges to the Columbia River. Multilayer protective barriers have been proposed as a means of limiting the flow of water through the waste sites (DOE 1987). A multiyear research program (managed jointly by Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company for the DOE) is aimed at assessing the performance of these barriers. One aspect of this program involves the use of computer models to predict barrier performance. Three modeling studies have already been conducted and a test plan was produced. The simulation work reported here was conducted by PNL and extends the previous modeling work. The purpose of this report are to understand phenomena that have been observed in the field and to provide information that can be used to improve hydrologic modeling of the protective barrier. An improved modeling capability results in better estimates of barrier performance. Better estimates can be used to improve the design of barriers and the assessment of their long-term performance.
Model Evaluation and Hindcasting: An Experiment with an Integrated Assessment Model
Chaturvedi, Vaibhav; Kim, Son H.; Smith, Steven J.; Clarke, Leon E.; Zhou, Yuyu; Kyle, G. Page; Patel, Pralit L.
2013-11-01T23:59:59.000Z
Integrated assessment models have been extensively used for analyzing long term energy and greenhouse emissions trajectories and have influenced key policies on this subject. Though admittedly these models are focused on the long term trajectories, how well these models are able to capture historical dynamics is an open question. In a first experiment of its kind, we present a framework for evaluation of such integrated assessment models. We use Global Change Assessment Model for this zero order experiment, and focus on the building sector results for USA. We calibrate the model for 1990 and run it forward up to 2095 in five year time steps. This gives us results for 1995, 2000, 2005 and 2010 which we compare to observed historical data at both fuel level and service level. We focus on bringing out the key insights for the wider process of model evaluation through our experiment with GCAM. We begin with highlighting that creation of an evaluation dataset and identification of key evaluation metric is the foremost challenge in the evaluation process. Our analysis highlights that estimation of functional form of the relationship between energy service demand, which is an unobserved variable, and its drivers is a significant challenge in the absence of adequate historical data for both the dependent and driver variables. Historical data availability for key metrics is a serious limiting factor in the process of evaluation. Interestingly, service level data against which such models need to be evaluated are itself a result of models. Thus for energy services, the best we can do is compare our model results with other model results rather than observed and measured data. We show that long term models, by the nature of their construction, will most likely underestimate the rapid growth in some services observed in a short time span. Also, we learn that modeling saturated energy services like space heating is easier than modeling unsaturated services like space cooling and understanding that how far a service is from its saturation level is a key question which we probably don’t have an answer to. Finally and most importantly, even if long term models partially miss the short term dynamics, the long term insights provides by these models is fairly robust. We conclude by highlighting that our work is the first step in the much wider process of integrated assessment model evaluation and will hence have its own limitations. Future evaluation research work should build upon this zero order experiment for improving our modeling of human and coupled earth systems.
Modeling of Reactor Kinetics and Dynamics
Matthew Johnson; Scott Lucas; Pavel Tsvetkov
2010-09-01T23:59:59.000Z
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.
DYNAMIC MODELING PROTON EXCHANGE MEMBRANE FUEL CELL
Mease, Kenneth D.
DYNAMIC MODELING PROTON EXCHANGE MEMBRANE FUEL CELL OVERVIEW Current/Completed Plug Power to garner SCAQMD funding for fuel cell testing GenCore system is sensitive to diluents · As built design stream to compensate for removal of EGR · Functionality of the modified GenCore Fuel Cell system
Modeling the Dynamics of Fermentation and Respiratory
Sheffield, University of
, 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
Receptor modeling assessment of particle total exposure assessment methodology data
Yakovleva, E.; Hopke, P.K.; Wallace, L.
1999-10-15T23:59:59.000Z
Data from the 1991 Particle Total Exposure Assessment Methodology (PTEAM) study in Riverside, CA, were analyzed using a new receptor modeling method. In this study, ambient (outdoor), indoor, and personal particulate matter (PM) concentrations and elemental concentrations of PM{sub 2.5} and PM{sub 10} were measured for a number of participants. These measurements made is possible to relate the pollution to which people were exposed throughout their daily activities with the outdoor air conditions. Personal daytime concentrations of the PM{sub 10} and majority of elements were significantly higher than outdoor or indoor concentrations, suggesting that a significant part of personal aerosol exposure is the result of personal daily activities. Possible sources of additional particulate mass include resuspension of particles that penetrate from the outdoors and formation of new particles during cooking, smoking, etc. Positive matrix factorization analysis was performed to describe the sources of personal exposure. To identify relative contribution of different sources, regression of the particulate matter mass against the factor contributions was performed. Major sources of PM{sub 2.5} were oil combustion, nonferrous metal operations, and motor vehicles. The mass contributions of particles from these sources were similar for outdoor air and personal exposure. Personal exposure to particles from these sources can be controlled by changing outdoor sources. The primary source of PM{sub 10} was soil.
Feature extraction for structural dynamics model validation
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
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.
Assessment of Combustion and Turbulence Models for the Simulation...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine Assessment of Combustion and Turbulence Models for the Simulation of Combustion...
Structural system identification: Structural dynamics model validation
Red-Horse, J.R.
1997-04-01T23:59:59.000Z
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.
Model for assessing bronchial mucus transport
Agnew, J.E.; Bateman, J.R.M.; Pavia, D.; Clarke, S.W.
1984-02-01T23:59:59.000Z
The authors propose a scheme for the assessment of regional mucus transport using inhaled Tc-99m aerosol particles and quantitative analysis of serial gamma-camera images. The model treats input to inner and intermediate lung regions as the total of initial deposition there plus subsequent transport into these regions from more peripheral airways. It allows for interregional differences in the proportion of particles deposited on the mucus-bearing conducting airways, and does not require a gamma image 24 hr after particle inhalation. Instead, distribution of particles reaching the respiratory bronchioles or alveoli is determined from a Kr-81m ventilation image, while the total amount of such deposition is obtained from 24-hr Tc-99m retention measured with a sensitive counter system. The model is applicable to transport by mucociliary action or by cough, and has been tested in ten normal and ten asthmatic subjects.
Model for a web based medical technology assessment system
Prabhu, Gopal
1999-01-01T23:59:59.000Z
Technology is the primary driving force for change in today's healthcare environment. Understanding the dynamics of medical technology and applying probative management measures can be accomplished with a medical technology assessment program...
The dynamic radiation environment assimilation model (DREAM)
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
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.
Direct modelling of envelope dynamics in resonant inverters
is to model the AC dynamics from input modulation to output envelops to facilitate optimised controller designDirect 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
Analytical modeling of balloon launch dynamics
Strganac, Thomas W
1980-01-01T23:59:59.000Z
Subject; Aerospace Engineer1ng ANALYTICAL MODELING OF BALLOON LAUNCH DYNAMICS A Thesis by THOMAS WILLIAM STRGANAC Approved as to sty1e and content by: (Chairman of Committee) (Member) (Member) (Head of Dep rtment) December 1980 ABSTRACT Analyt1... aerodynam1cs. Actual fl1ght data has been used to qualify the model via comparisons of the launch trans1ent configurations. DEDICATION To my father. . THOMAS JOHN STRGANAC 1922-1980 . . . who provided me the examp1e to fo1Iow in life. ACKNOWLEDGEMENTS...
Risk assessment compatible fire models (RACFMs)
Lopez, A.R.; Gritzo, L.A.; Sherman, M.P.
1998-07-01T23:59:59.000Z
A suite of Probabilistic Risk Assessment Compatible Fire Models (RACFMs) has been developed to represent the hazard posed by a pool fire to weapon systems transported on the B52-H aircraft. These models represent both stand-off (i.e., the weapon system is outside of the flame zone but exposed to the radiant heat load from fire) and fully-engulfing scenarios (i.e., the object is fully covered by flames). The approach taken in developing the RACFMs for both scenarios was to consolidate, reconcile, and apply data and knowledge from all available resources including: data and correlations from the literature, data from an extensive full-scale fire test program at the Naval Air Warfare Center (NAWC) at China Lake, and results from a fire field model (VULCAN). In the past, a single, effective temperature, T{sub f}, was used to represent the fire. The heat flux to an object exposed to a fire was estimated using the relationship for black body radiation, {sigma}T{sub f}{sup 4}. Significant improvements have been made by employing the present approach which accounts for the presence of temperature distributions in fully-engulfing fires, and uses best available correlations to estimate heat fluxes in stand-off scenarios.
Eutrophication risk assessment in coastal embayments using simple statistical models
Arhonditsis, George B.
Eutrophication risk assessment in coastal embayments using simple statistical models G. Arhonditsis for assessing the risk of eutrophication in marine coastal embayments. The procedure followed of exogenous nutrient loading. Ã? 2003 Elsevier Ltd. All rights reserved. Keywords: Eutrophication; Coastal
A Game-Theoretical Dynamic Model for Electricity Markets
Aswin Kannan
2010-10-06T23:59:59.000Z
Oct 6, 2010 ... Abstract: We present a game-theoretical dynamic model for competitive electricity markets.We demonstrate that the model can be used to ...
ESD.864 Modeling and Assessment for Policy, Spring 2011
Selin, Noelle
ESD.864 Modeling and Assessment for Policy explores how scientific information and quantitative models can be used to inform policy decision-making. Students will develop an understanding of quantitative modeling techniques ...
analytical model assessing: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
272 Coupled thermodynamic-dynamic semi-analytical model of Free Piston Stirling engines CERN Preprints Summary: The study of free piston Stirling engine (FPSE) requires both...
Dynamical Models for the Milky Way
Walter Dehnen; James Binney
1996-01-10T23:59:59.000Z
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.
Dr. Atul Jain
2005-04-17T23:59:59.000Z
This report outlines the progress on the development and application of Integrated Assessment Modeling of Carbon Sequestrations and Land Use Emissions supported by the DOE Office of Biological and Environmental Research (OBER), U.S. Department of Energy, Grant No. DOE-DE-FG02-01ER63069. The overall objective of this collaborative project between the University of Illinois at Urbana-Champaign (UIUC), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL) was to unite the latest advances in carbon cycle research with scientifically based models and policy-related integrated assessment tools that incorporate computationally efficient representations of the latest knowledge concerning science and emission trajectories, and their policy implications. As part of this research we accomplished the following tasks that we originally proposed: (1) In coordination with LLNL and ORNL, we enhanced the Integrated Science Assessment Model's (ISAM) parametric representation of the ocean and terrestrial carbon cycles that better represent spatial and seasonal variations, which are important to study the mechanisms that influence carbon sequestration in the ocean and terrestrial ecosystems; (2) Using the MiniCAM modeling capability, we revised the SRES (IPCC Special Report on Emission Scenarios; IPCC, 2000) land use emission scenarios; and (3) On the application front, the enhanced version of ISAM modeling capability is applied to understand how short- and long-term natural carbon fluxes, carbon sequestration, and human emissions contribute to the net global emissions (concentrations) trajectories required to reach various concentration (emission) targets. Under this grant, 21 research publications were produced. In addition, this grant supported a number of graduate and undergraduate students whose fundamental research was to learn a disciplinary field in climate change (e.g., ecological dynamics and ocean circulations) and then complete research on how this field could be linked to the other factors we need to consider in its dynamics (e.g., land use, ocean and terrestrial carbon sequestration and climate change).
assessment models risk: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
practice in the use of spreadsheets in business. Butler, Raymond J 2008-01-01 13 Eutrophication risk assessment in coastal embayments using simple statistical models...
Modelling and simulation of multidisciplinary dynamic systems Lead: A. Fakri.
Baudoin, GeneviÃ¨ve
Modelling and simulation of multidisciplinary dynamic systems Lead: A. Fakri. Permanent members: P. Integration of various engineering disciplines and the consideration of the dynamic control need a concurrent suited for the energy exchanges to study multidisciplinary dynamic engineering systems modelling. Our
ONGOING RESEARCH PROJECTS Model of tropical forest structure and dynamics
Hill, Jeffrey E.
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
Organizational capabilities assessment: a dynamic methodology, methods and a tool for supporting
Paris-Sud XI, Université de
Organizational capabilities assessment: a dynamic methodology, methods and a tool for supporting organizational diagnosis Philippe RAUFFET, Catherine DA CUNHA, Alain BERNARD IRCCyN laboratory Ecole Centrale in organizations in order to develop collective competencies, called also organizational capabilities, around
Gradient Navigation Model for Pedestrian Dynamics
Felix Dietrich; Gerta Köster
2014-05-14T23:59:59.000Z
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.
Unbounded dynamics in dissipative flows: Rössler model
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
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.
Student Learning Assessment: Towards an Environmental Model for
Bieber, Michael
Student Learning Assessment: Towards an Environmental Model for Academic and Student Services in the classroom. · And, implicitly, design assessment methods that lead to documentation and improvement. #12;MSCHE and Student Learning Assessment #12;The NJIT Academic Affairs Institutional Level Learning Goals 1
Dynamics of an Economics Model for Generation Coupled to the OPA Power Transmission Model
Dobson, Ian
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
Towards a Simplified Dynamic Wake Model using POD Analysis
Bastine, David; Wächter, Matthias; Peinke, Joachim
2014-01-01T23:59:59.000Z
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...
Linking Dynamical and Population Genetic Models of Persistent Viral Infection
Kelly, John K.; Williamson, Scott; Orive, Maria E.; Smith, Marilyn S.; Holt, Robert D.
2003-07-01T23:59:59.000Z
This article develops a theoretical framework to link dynamical and population genetic models of persistent viral infection. This linkage is useful because, while the dynamical and population genetic theories have developed ...
Accepted Manuscript Title: Quantitative assessment of dynamic control of fingertip
Valero-Cuevas, Francisco
spring prone to buckling between the thumb and first finger to quantify dynamic control over, lateral pinch, and tripod pinch strength, Box and Blocks, and 9- hole peg test. Six of 10 pollicized hands
Assessment of Tools and Data for System-Level Dynamic Analyses
Steven J. Piet; Nick R. Soelberg
2011-06-01T23:59:59.000Z
The only fuel cycle for which dynamic analyses and assessments are not needed is the null fuel cycle - no nuclear power. For every other concept, dynamic analyses are needed and can influence relative desirability of options. Dynamic analyses show how a fuel cycle might work during transitions from today's partial fuel cycle to something more complete, impact of technology deployments, location of choke points, the key time lags, when benefits can manifest, and how well parts of fuel cycles work together. This report summarizes the readiness of existing Fuel Cycle Technology (FCT) tools and data for conducting dynamic analyses on the range of options. VISION is the primary dynamic analysis tool. Not only does it model mass flows, as do other dynamic system analysis models, but it allows users to explore various potential constraints. The only fuel cycle for which constraints are not important are those in concept advocates PowerPoint presentations; in contrast, comparative analyses of fuel cycles must address what constraints exist and how they could impact performance. The most immediate tool need is extending VISION to the thorium/U233 fuel cycle. Depending on further clarification of waste management strategies in general and for specific fuel cycle candidates, waste management sub-models in VISION may need enhancement, e.g., more on 'co-flows' of non-fuel materials, constraints in waste streams, or automatic classification of waste streams on the basis of user-specified rules. VISION originally had an economic sub-model. The economic calculations were deemed unnecessary in later versions so it was retired. Eventually, the program will need to restore and improve the economics sub-model of VISION to at least the cash flow stage and possibly to incorporating cost constraints and feedbacks. There are multiple sources of data that dynamic analyses can draw on. In this report, 'data' means experimental data, data from more detailed theoretical or empirical calculations on technology performance, and assumptions such as the earliest date a technology can be deployed. The only fuel cycles for which we currently have adequate data are those we are sure we will never build, e.g., a PUREX plant in the U.S. For actual candidates, even for once through LWRs, there remain missing data such as how the fuel cycle would be completed with a geologic repository. The most immediate data needs are probably basic reactor physics data for new concepts and data associated with waste management for anything other than current technology. The readiness of tools and data is fluid and depends on what purposes are envisioned to drive upcoming analyses and further definition of the waste-related characteristics of fuel cycle candidates. Tools and data sets evolve as needs evolve. Thus, much of the document explains that if the FCT program wants a certain type of analysis, then the tools and data needs are as indicated. For example, functions can be treated as either commodities or facilities. Reactors, separation, fuel fabrication, repository are treated as facility types. Other functions such as uranium mining, conversion, enrichment, and waste packaging and non-repository disposal are treated as commodities and therefore not modeled as extensively. In summary, the tools are functional and can answer many fuel cycle questions but some analyses will require that the tools be modified to support those analyses.
Solid Oxide Fuel Cell: Perspective of Dynamic Modeling and Control
Huang, Biao
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
Dynamic Bayesian Networks model to estimate process availability.
Paris-Sud XI, Université de
Dynamic Bayesian Networks model to estimate process availability. Weber P. Centre de Recherche en reported here explores a new methodology to develop Dynamic Bayesian Network-based Availability of the system availability estimation comparing DBN model with the classical Markov chain model. Keywords
Albert, Réka
with a random network with a given degree distribution P(k). Mark edges with probability T. DisregardThe two faces of network dynamics Evolving network models describe the dynamics (assembly, evolution) OF networks by the addition/removal of nodes and edges. It is possible to have network dynamics
A dynamic model for the Lagrangian stochastic dispersion coefficient
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
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.
Event-Based Approach to Modelling Dynamic Architecture
Paris-Sud XI, UniversitÃ© de
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
Stochastic modeling of lift and drag dynamics under turbulent conditions
Peinke, Joachim
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
VISION -- A Dynamic Model of the Nuclear Fuel Cycle
J. J. Jacobson; A. M. Yacout; S. J. Piet; D. E. Shropshire; G. E. Matthern
2006-02-01T23:59:59.000Z
The Advanced Fuel Cycle Initiative’s (AFCI) fundamental objective is to provide technology options that – if implemented – would enable long-term growth of nuclear power while improving sustainability and energy security. The AFCI organization structure consists of four areas; Systems Analysis, Fuels, Separations and Transmutations. The Systems Analysis Working Group is tasked with bridging the program technical areas and providing the models, tools, and analyses required to assess the feasibility of design and deploy¬ment options and inform key decision makers. An integral part of the Systems Analysis tool set is the development of a system level model that can be used to examine the implications of the different mixes of reactors, implications of fuel reprocessing, impact of deployment technologies, as well as potential “exit” or “off ramp” approaches to phase out technologies, waste management issues and long-term repository needs. The Verifiable Fuel Cycle Simulation Model (VISION) is a computer-based simulation model that allows performing dynamic simulations of fuel cycles to quantify infrastructure requirements and identify key trade-offs between alternatives. VISION is intended to serve as a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies.
Using species distribution models to inform IUCN Red List assessments
Syfert, Mindy M.; Joppa, Lucas; Smith, Matthew J.; Coomes, David A.; Bachman, Steven P.; Brummitt, Neil A.
2014-07-26T23:59:59.000Z
.g. hurricanes) or anthropogenic effects (e.g. deforestation) not included in the model fitting process (Elith and Leathwick 2009). Additionally, the SDM approach we have taken here does not explicitly take into account non-equilibrium species dynamics. While...
Hydrodynamic and Ecological Assessment of Nearshore Restoration: A Modeling Study
Yang, Zhaoqing; Sobocinski, Kathryn L.; Heatwole, Danelle W.; Khangaonkar, Tarang; Thom, Ronald M.; Fuller, Roger
2010-04-10T23:59:59.000Z
Along the Pacific Northwest coast, much of the estuarine habitat has been diked over the last century for agricultural land use, residential and commercial development, and transportation corridors. As a result, many of the ecological processes and functions have been disrupted. To protect coastal habitats that are vital to aquatic species, many restoration projects are currently underway to restore the estuarine and coastal ecosystems through dike breaches, setbacks, and removals. Information on physical processes and hydrodynamic conditions are critical for the assessment of the success of restoration actions. Restoration of a 160- acre property at the mouth of the Stillaguamish River in Puget Sound has been proposed. The goal is to restore native tidal habitats and estuary-scale ecological processes by removing the dike. In this study, a three-dimensional hydrodynamic model was developed for the Stillaguamish River estuary to simulate estuarine processes. The model was calibrated to observed tide, current, and salinity data for existing conditions and applied to simulate the hydrodynamic responses to two restoration alternatives. Responses were evaluated at the scale of the restoration footprint. Model data was combined with biophysical data to predict habitat responses at the site. Results showed that the proposed dike removal would result in desired tidal flushing and conditions that would support four habitat types on the restoration footprint. At the estuary scale, restoration would substantially increase the proportion of area flushed with freshwater (< 5 ppt) at flood tide. Potential implications of predicted changes in salinity and flow dynamics are discussed relative to the distribution of tidal marsh habitat.
Factoring Gaussian Precision Matrices for Linear Dynamic Models
Frankel, Joe; King, Simon
2007-01-01T23:59:59.000Z
The linear dynamic model (LDM), also known as the Kalman filter model, has been the subject of research in the engineering, control, and more recently, machine learning and speech technology communities. The Gaussian noise processes are usually...
Learning Usability Assessment Models for Web Sites
Davis, Paul
2012-02-14T23:59:59.000Z
students pursuing advanced degrees in the area of computer-human interaction. These students were divided into two groups and given different scenarios of use of a Web site. They assessed the usability of Web pages from the site, and their data was divided...
Static and Dynamic Debugging of Modelica Models Adrian Pop1
Zhao, Yuxiao
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
A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling
Paris-Sud XI, Université de
A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling and Control L. Nehaoua and dynamics modeling will be presented. Some results are shown, validating the actutation requirements and platform control. 1. INTRODUCTION Road safety has become a major political and economical issue. While all
A Qualitative Simulation Approach for Fuzzy Dynamical Models
Bontempi, Gianluca
.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
Computational Modeling of Brain Dynamics during Repetitive Head Motions
Burtscher, Martin
Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School the HIC scale to arbitrary head motions. Our simulations of the brain dynamics in sagittal and horizontal injury modeling, resonance effects 1 Introduction A rapid head motion can result in a severe brain injury
A Dynamic Model of Social Network Formation Brian Skyrms 1
Pemantle, Robin
A Dynamic Model of Social Network Formation Brian Skyrms 1 Robin Pemantle 2;3 ABSTRACT: We consider a dynamic social network model in which agents play repeated games in pairings determined by a stochastically evolving social network. In- dividual agents begin to interact at random, with the interactions
MODELLING THE ONSET OF DYNAMIC Importance of the Vertical Dimension
Johansen, Tom Henning
block models of an elastic slider under dry friction. I apply AmontonsCoulomb friction at the block levelMODELLING THE ONSET OF DYNAMIC FRICTION Importance of the Vertical Dimension by JØRGEN TRØMBORG of the onset of dynamic friction. Optical methods give access to the sliding interface before and during
Wind resource assessment with a mesoscale non-hydrostatic model
Boyer, Edmond
Wind resource assessment with a mesoscale non- hydrostatic model Vincent Guénard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k
ASSESSING FRANCE AS A MODEL OF SOCIETAL SUCCESS
Boyer, Edmond
of this "French model": the French economy being heavily regulated, the well-oiled state tightly controls market crisis," "The French model: Vive la difference!"2 ), and also from free-market minded internationalASSESSING FRANCE AS A MODEL OF SOCIETAL SUCCESS Ã?loi Laurent Sciences-Po MichÃ¨le Lamont Harvard
Binaural model-based speech intelligibility enhancement and assessment in
#12;Binaural model-based speech intelligibility enhancement and assessment in hearing aids beamforming and the effect on binaural cues and speech intelligibility . . . . . . . . . . 31 2.3.4 Cepstral smoothing of masks . . . . . . . . . . . . . . . . . . 35 2.4 Binaural CASA speech
C. Müller; E. D. Hughes; G. F. Niederauer; H. Wilkening; J. R. Travis; J. W. Spore; P. Royl; W. Baumann
1998-10-01T23:59:59.000Z
Los Alamos National Laboratory (LANL) and Forschungszentrum Karlsruhe (FzK) are developing GASFLOW, a three-dimensional (3D) fluid dynamics field code as a best- estimate tool to characterize local phenomena within a flow field. Examples of 3D phenomena include circulation patterns; flow stratification; hydrogen distribution mixing and stratification; combustion and flame propagation; effects of noncondensable gas distribution on local condensation and evaporation; and aerosol entrainment, transport, and deposition. An analysis with GASFLOW will result in a prediction of the gas composition and discrete particle distribution in space and time throughout the facility and the resulting pressure and temperature loadings on the walls and internal structures with or without combustion. A major application of GASFLOW is for predicting the transport, mixing, and combustion of hydrogen and other gases in nuclear reactor containment and other facilities. It has been applied to situations involving transporting and distributing combustible gas mixtures. It has been used to study gas dynamic behavior in low-speed, buoyancy-driven flows, as well as sonic flows or diffusion dominated flows; and during chemically reacting flows, including deflagrations. The effects of controlling such mixtures by safety systems can be analyzed. The code version described in this manual is designated GASFLOW 2.1, which combines previous versions of the United States Nuclear Regulatory Commission code HMS (for Hydrogen Mixing Studies) and the Department of Energy and FzK versions of GASFLOW. The code was written in standard Fortran 90. This manual comprises three volumes. Volume I describes the governing physical equations and computational model. Volume II describes how to use the code to set up a model geometry, specify gas species and material properties, define initial and boundary conditions, and specify different outputs, especially graphical displays. Sample problems are included. Volume III contains some of the assessments performed by LANL and FzK
Quantitative Adaptation Analytics for Assessing Dynamic Systems of Systems.
Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.; Le, Hai D.; Kao, Gio K; Melander, Darryl J.; Longsine, Dennis Earl [Sandia National Laboratories, Unknown, Unknown; Vander Meer, Robert Charles,
2015-01-01T23:59:59.000Z
Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.
RAVEN and Dynamic Probabilistic Risk Assessment: Software overview
Andrea Alfonsi; Cristian Rabiti; Diego Mandelli; Joshua Cogliati; Robert Kinoshita; Antonio Naviglio
2014-06-01T23:59:59.000Z
RAVEN is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. The initial development was aimed to provide dynamic risk analysis capabilities to the Thermo-Hydraulic code RELAP-7 [], currently under development at the Idaho National Laboratory. Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose probabilistic and uncertainty quantification platform, capable to agnostically communicate with any system code. This agnosticism has been employed by providing Application Programming Interfaces (APIs). These interfaces are used to allow RAVEN to interact with any code as long as all the parameters that need to be perturbed are accessible by inputs files or via python interfaces. RAVEN is capable to investigate the system response, investigating the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. The paper presents an overview of the software capabilities and their implementation schemes followed by some application examples.
Dynamic Modeling of Cascading Failure in Power Systems
Song, Jiajia; Ghanavati, Goodarz; Hines, Paul D H
2014-01-01T23:59:59.000Z
The modeling of cascading failure in power systems is difficult because of the many different mechanisms involved; no single model captures all of these mechanisms. Understanding the relative importance of these different mechanisms is an important step in choosing which mechanisms need to be modeled for particular types of cascading failure analysis. This work presents a dynamic simulation model of both power networks and protection systems, which can simulate a wider variety of cascading outage mechanisms, relative to existing quasi-steady state (QSS) models. The model allows one to test the impact of different load models and protections on cascading outage sizes. This paper describes each module of the developed dynamic model and demonstrates how different mechanisms interact. In order to test the model we simulated a batch of randomly selected $N-2$ contingencies for several different static load configurations, and found that the distribution of blackout sizes and event lengths from the proposed dynamic...
Dynamic Modeling in Solid-Oxide Fuel Cells Controller Design
Lu, Ning; Li, Qinghe; Sun, Xin; Khaleel, Mohammad A.
2007-06-28T23:59:59.000Z
In this paper, a dynamic model of the solid-oxide fuel cell (SOFC) power unit is developed for the purpose of designing a controller to regulate fuel flow rate, fuel temperature, air flow rate, and air temperature to maintain the SOFC stack temperature, fuel utilization rate, and voltage within operation limits. A lumped model is used to consider the thermal dynamics and the electro-chemial dynamics inside an SOFC power unit. The fluid dynamics at the fuel and air inlets are considered by using the in-flow ramp-rates.
Small-Signal Stability Assessment of Active Distribution Networks with Dynamic Loads
Pota, Himanshu Roy
the flow of power and the voltage profiles of the system and these profiles are different for different types of loads [3]. In addition to the power flow at and around N. K. Roy, H. R. Pota, and T. F. OrchiSmall-Signal Stability Assessment of Active Distribution Networks with Dynamic Loads N. K. Roy
Statewide and Electricity-Sector Models for Economic Assessments of
Statewide and Electricity-Sector Models for Economic Assessments of Hawai`i Clean Energy Policies 9.2 Deliverable Economic and Environmental Modeling of Island Energy Systems By the Hawai`i Natural of Hawai`i Economic Research Organization August 2012 #12;2 Acknowledgement: This material is based upon
Generic solar photovoltaic system dynamic simulation model specification.
Ellis, Abraham; Behnke, Michael Robert; Elliott, Ryan Thomas
2013-10-01T23:59:59.000Z
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.
Assessment of dynamic energy conversion systems for radioisotope heat sources
Thayer, G.R.; Mangeng, C.A.
1985-06-01T23:59:59.000Z
The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.
Model-based Safety Risk Assessment
Lindsay, Peter
development life-cycle, in order to identify critical system requirements, such as safety requirements their effectiveness, early in the system development life-cycle, on models derived directly from natural language of functional requirements of arbitrary detail whether it is very early in the life-cycle when functions
Reisslein, Martin
IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 0, NO. 0, MONTH YEAR 1 On-line Dynamic Security Assessment is proposed for on-line dynamic security assessment (DSA), with the objective of mitigating the impact of viable small DTs. The security classification decision for on-line DSA is obtained via a weighted voting
Optimal control with adaptive internal dynamics models
Mitrovic, Djordje; Klanke, Stefan; Vijayakumar, Sethu
2008-01-01T23:59:59.000Z
Optimal feedback control has been proposed as an attractive movement generation strategy in goal reaching tasks for anthropomorphic manipulator systems. The optimal feedback control law for systems with non-linear dynamics ...
REGULAR ARTICLE A Simple Dynamic Model of Respiratory Pump
Fontecave-Jallon, Julie
). 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
Modeling and Management of Nonlinear Dependencies Copulas in Dynamic Financial
Ulm, Universität
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
UNEDITED PREPRINT Building a dynamic growth model for trembling
García, Oscar
UNEDITED PREPRINT Building a dynamic growth model for trembling aspen in Western Canada without age for even-aged thinned or unthinned stands dominated by trembling aspen. Estimation used permanent sample words: Forest growth and yield, Populus tremuloides, quacking aspen, thinning, dynamical systems, TAG. 1
Dynamic wind turbine models in power system simulation tool
Dynamic wind turbine models in power system simulation tool DIgSILENT Anca D. Hansen, Florin Iov Iov, Poul SÃ¸rensen, Nicolaos Cutululis, Clemens Jauch, Frede Blaabjerg Title: Dynamic wind turbine system simulation tool PowerFactory DIgSILENT for different wind turbine concepts. It is the second
Dynamic (G2) Model Design Document, 24590-WTP-MDD-PR-01-002, Rev. 12
Deng, Yueying; Kruger, Albert A.
2013-12-16T23:59:59.000Z
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.
Safety assessment document for the Dynamic Test Complex B854
Odell, B.N.; Pfeifer, H.E.
1981-12-11T23:59:59.000Z
A safety assessment was performed to determine if potential accidents at the 854 Complex at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The credible accidents that might have an effect on these facilities or have off-site consequences were considered. These were earthquake, extreme wind (including missiles), lightning, flood, criticality, high explosive (HE) detonation that disperses uranium and beryllium, spontaneous oxidation of plutonium, explosions due to finely divided particles, and a fire. Seismic and extreme wind (including missiles) analyses indicate that the buildings are basically sound. The lightning protection system is in the process of being upgraded to meet AMCR 385-100. These buildings are located high above the dry creek bed so that a flood is improbable. The probability of high explosive detonation involving plutonium is very remote since the radioactive materials are encased and plutonium and HE are not permitted concurrently in the same area at Site 300. (The exception to this policy is that explosive actuating devices are sometimes located in assemblies containing fissile materials. However, an accidental actuation will not affect the safe containment of the plutonium within the assembly.) There is a remote possibility of an HE explosion involving uranium and beryllium since these are permitted in the same area.The possibility of a criticality accident is very remote since the fissile materials are doubly encased in stout metal containers. All operations involving these materials are independently reviewed and inspected by the Criticality Safety Office. It was determined that a fire was unlikely due to the low fire loading and the absence of ignition sources. It was also determined that the consequences of any accidents were reduced by the remote location of these facilities, their design, and by administrative controls.
Symbolic Dynamics in a Matching Labour Market Model
Diana A. Mendes; Vivaldo M. Mendes; J. Sousa Ramos
2006-08-01T23:59:59.000Z
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.
2.003 Modeling Dynamics and Control I, Spring 2002
Trumper, David L.
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 ...
Human Growth and Body Weight Dynamics: An Integrative Systems Model
Rahmandad, Hazhir
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 ...
Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion
. 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
Modeling and control of undesirable dynamics in atomic force microscopes
El Rifai, Osamah M
2002-01-01T23:59:59.000Z
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 ...
Models of dynamic RNA regulation in mammalian cells
Rabani, Michal
2013-01-01T23:59:59.000Z
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 ...
Dynamic Modelling and Control Design of Pre-combustion Power
Foss, Bjarne A.
- pressors, gas and steam turbines and a heat recovery system. Analysis of dynamic models at an early stage principles. The pre- combustion gas power cycle plants consist of reformers and separation units, com
Applications of axial and radial compressor dynamic system modeling
Spakovszky, Zoltán S. (Zoltán Sándor), 1972-
2001-01-01T23:59:59.000Z
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. ...
Model reduction for nonlinear dynamical systems with parametric uncertainties
Zhou, Yuxiang Beckett
2012-01-01T23:59:59.000Z
Nonlinear dynamical systems are known to be sensitive to input parameters. In this thesis, we apply model order reduction to an important class of such systems -- one which exhibits limit cycle oscillations (LCOs) and ...
COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS
COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS Ugur Pasaogullari and Chao-dimensional model has been developed to simulate solid oxide fuel cells (SOFC). The model fully couples current density operation. INTRODUCTION Solid oxide fuel cells (SOFC) are among possible candidates
Modeling exchange rate dependence dynamics at different time horizons
Embrechts, Paul
, 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
RESEARCH ARTICLE Modelling multi-species response to landscape dynamics
Kleyer, Michael
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 Ã Species distribution model Ã Habitat model Ã Urban brownfields Ã Model averaging Ã
A Diffusion Model in Population Genetics with Mutation and Dynamic
O'Leary, Michael
A Diffusion Model in Population Genetics with Mutation and Dynamic Fitness Mike O'Leary Department of Mathematics Towson University May 24, 2008 Mike O'Leary (Towson University) A Diffusion Model in Genetics May Miller, Georgetown University Mike O'Leary (Towson University) A Diffusion Model in Genetics May 24, 2008
Developing Generic Dynamic Models for the 2030 Eastern Interconnection Grid
Kou, Gefei [ORNL; Hadley, Stanton W [ORNL; Markham, Penn N [ORNL; Liu, Yilu [ORNL
2013-12-01T23:59:59.000Z
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.
Fire models for assessment of nuclear power plant fires
Nicolette, V.F.; Nowlen, S.P.
1989-01-01T23:59:59.000Z
This paper reviews the state-of-the-art in available fire models for the assessment of nuclear power plants fires. The advantages and disadvantages of three basic types of fire models (zone, field, and control volume) and Sandia's experience with these models will be discussed. It is shown that the type of fire model selected to solve a particular problem should be based on the information that is required. Areas of concern which relate to all nuclear power plant fire models are identified. 17 refs., 6 figs.
Vermont, University of
MODELING/GIS, RISK ASSESSMENT, ECONOMIC IMPACT Household Model of Chagas Disease Vectors (Hemiptera vectors (Hemiptera: Reduviidae) of the causative parasite Trypanosoma cruzi (Kinetoplastida bitten by infected insect vectors. There are 130 species in the subfamily Triatominae (Hemiptera
Dynamic reactor modeling with applications to SPR and ZEDNA.
Suo-Anttila, Ahti Jorma
2011-12-01T23:59:59.000Z
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.
Mesoscale modeling of phase transition dynamics of thermoresponsive polymers
Li, Zhen; Li, Xuejin; Karniadakis, George Em
2015-01-01T23:59:59.000Z
We present a non-isothermal mesoscopic model for investigation of the phase transition dynamics of thermoresponsive polymers. Since this model conserves energy in the simulations, it is able to correctly capture not only the transient behavior of polymer precipitation from solvent, but also the energy variation associated with the phase transition process. Simulations provide dynamic details of the thermally induced phase transition and confirm two different mechanisms dominating the phase transition dynamics. A shift of endothermic peak with concentration is observed and the underlying mechanism is explored.
ERCOT's Dynamic Model of Wind Turbine Generators: Preprint
Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.
2005-08-01T23:59:59.000Z
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.
Towards an assessment of skill acquisition in student modelling
Yacef, Kalina
/her operational skill in dynamic and highly risky domains, such as Air Traffic Control, nuclear plant operations,leila]@cmis.csiro.au Abstract: This paper presents an approach to student modelling in the context of a simulation-based ITS of the expertise. Examples are given in the domain of Air Traffic Control simulation training for conflict
Assessing the Power Requirements for Sawtooth Control in ITER Through Modelling and Joint Experiments
Dynamic competition model for construction contractors
Kim, Hyung Jin
2004-01-01T23:59:59.000Z
as an entity in a dynamic system, in which every entity is a profit optimizer responding to market conditions as well as its competitors' actions. In construction, the issue of competition has been focused on competitive bidding, which is a critical mechanism...
Human Muscle Fatigue Model in Dynamic Motions
Boyer, Edmond
into account. In this paper, each human joint is assumed to be controlled by two muscle groups to generate on motor units pattern. They demonstrated the relationship among muscle activation, fatigue and recovery fatigue trend in static working posture (elbow = 90 , shoulder = 30 ), but in dynamic working situation
Dynamic competition model for construction contractors
Kim, Hyung Jin
2004-01-01T23:59:59.000Z
as an entity in a dynamic system, in which every entity is a profit optimizer responding to market conditions as well as its competitors' actions. In construction, the issue of competition has been focused on competitive bidding, which is a critical mechanism...
Bright, Ryan M., E-mail: ryan.m.bright@ntnu.no; Cherubini, Francesco; Stromman, Anders H.
2012-11-15T23:59:59.000Z
Life cycle assessment (LCA) can be an invaluable tool for the structured environmental impact assessment of bioenergy product systems. However, the methodology's static temporal and spatial scope combined with its restriction to emission-based metrics in life cycle impact assessment (LCIA) inhibits its effectiveness at assessing climate change impacts that stem from dynamic land surface-atmosphere interactions inherent to all biomass-based product systems. In this paper, we focus on two dynamic issues related to anthropogenic land use that can significantly influence the climate impacts of bioenergy systems: i) temporary changes to the terrestrial carbon cycle; and ii) temporary changes in land surface albedo-and illustrate how they can be integrated within the LCA framework. In the context of active land use management for bioenergy, we discuss these dynamics and their relevancy and outline the methodological steps that would be required to derive case-specific biogenic CO{sub 2} and albedo change characterization factors for inclusion in LCIA. We demonstrate our concepts and metrics with application to a case study of transportation biofuel sourced from managed boreal forest biomass in northern Europe. We derive GWP indices for three land management cases of varying site productivities to illustrate the importance and need to consider case- or region-specific characterization factors for bioenergy product systems. Uncertainties and limitations of the proposed metrics are discussed. - Highlights: Black-Right-Pointing-Pointer A method for including temporary surface albedo and carbon cycle changes in Life Cycle Impact Assessment (LCIA) is elaborated. Black-Right-Pointing-Pointer Concepts are applied to a single bioenergy case whereby a range of feedstock productivities are shown to influence results. Black-Right-Pointing-Pointer Results imply that case- and site-specific characterization factors can be essential for a more informed impact assessment. Black-Right-Pointing-Pointer Uncertainties and limitations of the proposed methodologies are elaborated.
Diagnostic indicators for integrated assessment models of climate policy
Kriegler, Elmar; Petermann, Nils; Krey, Volker; Schwanitz, Jana; Luderer, Gunnar; Ashina, Shuichi; Bosetti, Valentina; Eom, Jiyong; Kitous, Alban; Mejean, Aurelie; Paroussos, Leonidas; Sano, Fuminori; Turton, Hal; Wilson, Charlie; Van Vuuren, Detlef
2015-01-01T23:59:59.000Z
Integrated assessments of how climate policy interacts with energy-economic systems can be performed by a variety of models with different functional structures. This article proposes a diagnostic scheme that can be applied to a wide range of integrated assessment models to classify differences among models based on their carbon price responses. Model diagnostics can uncover patterns and provide insights into why, under a given scenario, certain types of models behave in observed ways. Such insights are informative since model behavior can have a significant impact on projections of climate change mitigation costs and other policy-relevant information. The authors propose diagnostic indicators to characterize model responses to carbon price signals and test these in a diagnostic study with 11 global models. Indicators describe the magnitude of emission abatement and the associated costs relative to a harmonized baseline, the relative changes in carbon intensity and energy intensity and the extent of transformation in the energy system. This study shows a correlation among indicators suggesting that models can be classified into groups based on common patterns of behavior in response to carbon pricing. Such a classification can help to more easily explain variations among policy-relevant model results.
Structure formation: Models, Dynamics and Status
T. Padmanabhan
1995-08-25T23:59:59.000Z
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.
A Dynamic Model with Import Quota Constraints
Basak, Suleyman
2004-07-09T23:59:59.000Z
The analysis of import quotas is predominantly based on a static model, which is unable to capture the fact that a quota is imposed over a period of time. This article develops a continuous-time model ...
RELAP5/MOD3 subcooled boiling model assessment
Devkin, A.S.; Podosenov, A.S. [Russian Research Center, Moscow (Russian Federation). Nuclear Safety Inst.
1998-05-01T23:59:59.000Z
This report presents the assessment of the RELAP5/Mod3 (5m5 version) code subcooled boiling process model which is based on a variety of experiments. The accuracy of the model is confirmed for a wide range of regime parameters for the case of uniform heating along the channel. The condensation rate is rather underpredicted, which may lead to considerable errors in void fraction behavior prediction in subcooled boiling regimes for nonuniformly or unheated channels.
Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models
Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models J. R. Mc carbon capture and storage, 2) a natural gas combined cycle technology with carbon capture and storage 1 emissions growth. Both the magnitude and rate of technological change toward low- or no-carbon emitting
Assessing streamaquifer interactions through inverse modeling of flow routing q
Szilagyi, Jozsef
Assessing streamÂaquifer interactions through inverse modeling of flow routing q Jozsef Szilagyi a and Nieber, 1977; Troch et al., 1993; Brutsaert and Lopez, 1998; Szilagyi et al., 1998; Par- lange et al., 2001; Szilagyi, 2003a). Knowledge of this inter- action between streamflow and groundwater during flood
Yuan, Fengming [ORNL; Yi, Shuhua [Cold and Arid Regions Environmental and Engineering Research Institute, CAS; McGuire, A. David [University of Alaska; Johnson, Kristopher D [University of Alaska, Fairbanks; Liang, Jingjing [University of Alaska, Fairbanks; Harden, Jennifer [USGS, Menlo Park, CA; Kasischke, Eric S. [University of Maryland, College Park; Kurz, Werner [Canadian Forest Service
2012-01-01T23:59:59.000Z
Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites and evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at ;0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink strength of boreal forests. It is also important for large-scale biogeochemical and earth system models to include organic soil dynamics in applications to assess regional C dynamics of boreal forests responding to warming and changes in fire regime.
Long-wave models of thin film fluid dynamics
A. J. Roberts
1994-11-04T23:59:59.000Z
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.
Modeling Lake Erie ice dynamics: Process studies , Haoguo Hu2
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
Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS
Shapiro, Benjamin
ABSTRACT Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS OF ELECTRO an algorithm to steer indi- vidual particles inside the EWOD system by control of actuators already present number of actuators available in the EWOD system. #12;MODELING, SIMULATING, AND CONTROLLING THE FLUID
Controlling Social Dynamics with a Parametrized Model of Floor Regulation
Das, Suman
Controlling Social Dynamics with a Parametrized Model of Floor Regulation Crystal Chao, Andrea L is to build autonomous robot controllers for successfully engaging in human-like turn-taking interactions. Towards this end, we present CADENCE, a novel computational model and architecture that explicitly reasons
Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems
Sastry, S. Shankar
manipulation in manufacturing [2], gene regulation in cells [3], and power generation in electrical systems [41 Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems Samuel A. Burden, Shai Revzen system. We demonstrate reduction of a highÂdimensional underactuated mechanical model for terrestrial
Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations
Burtscher, Martin
.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
Numerically Estimating Internal Models of Dynamic Virtual Objects
Sekuler, Robert
human subjects to manipulate a computer-animated virtual object. This virtual object (vO) was a high, human cognition, human information processing, ideal performer, internal model, virtual object, virtual, specifically how humans acquire an internal model of a dynamic virtual object. Our methodology minimizes
Thermodiffusion in model nanofluids by molecular dynamics simulations
Paris-Sud XI, Université de
1 Thermodiffusion in model nanofluids by molecular dynamics simulations G. Galliero1,2,* , S. Volz3-Jones fluids and for model nanofluids (spherical non-metallic nanoparticles + Lennard-Jones fluid) where concentration. Then, in nanofluids in the liquid state, by changing the nature of the nanoparticle (size, mass
Passive dynamic walking with knees : a point foot model
Hsu Chen, Vanessa F. (Vanessa Fang)
2007-01-01T23:59:59.000Z
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 ...
Variational Inference in Stochastic Dynamic Environmental Models Dan Cornford1
Roulstone, Ian
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
Integrated science model for assessment of climate change
Jain, A.K.; Wuebbles, D.J. [Lawrence Livermore National Lab., CA (United States); Kheshgi, H.S. [Exxon Research and Engineering Co., Annandale, NJ (United States)
1994-04-01T23:59:59.000Z
Integrated assessment models are intended to represent processes that govern physical, ecological, economic and social systems. This report describes a scientific model relating emissions to global temperature and sea level. This model is intended to be one component of an integrated assessment model which is, of course, much more comprehensive. The model is able to reproduce past changes in CO{sub 2} concentration, global temperature, and sea level. The model is used to estimate the emissions rates required to lead to stabilization of CO{sub 2} at various levels. The model is also used to estimate global temperature rise, the rate of temperature change, and sea level rise driven by IPCC emissions scenarios. The emission of fossil fuel CO{sub 2} is modeled to have the largest long term effect on climate. Results do show the importance of expected changes of trace greenhouse gases other than CO{sub 2} in the near future. Because of the importance of these other trace gases, further work is recommended to more accurately estimate their effects.
Comprehensive country energy assessments using the MARKAL-MACRO model
Reisman, A.W.
1997-07-01T23:59:59.000Z
A number of comprehensive country energy assessments were performed in the late 1970s and early 1980s in cooperation with the governments of various countries. The assessments provided a framework for analyzing the impacts of various national strategies for meeting energy requirements. These analyses considered the total energy framework. Economics, energy supply, national resources, energy use, environmental impacts, technologies, energy efficiencies, and sociopolitical impacts were some of the factors addressed. These analyses incorporated the best available data bases and computer models to facilitate the analyses. National policy makers identified the various strategies to examine. The results of the analyses were provided to the national policy makers to support their decision making. Almost 20 years have passed since these assessments were performed. There have been major changes in energy supply and use, technologies, economics, available resources, and environmental concerns. The available tools for performing the assessments have improved drastically. The availability of improved computer modeling, i.e., MARKAL-MACRO, and improved data collection methods and data bases now permit such assessments to be performed in a more sophisticated manner to provide state of the art support to policy makers. The MARKAL-MACRO model was developed by Brookhaven National Laboratory over the last 25 years to support strategic energy planning. It is widely used in the international community for integrating analyses of environmental options, such as reduction of greenhouse gas emissions. It was used to perform the analyses in the least cost energy strategy study for the Energy Policy Act of 1992. Improvements continue to be made to MARKAL-MACRO and its capabilities extended. A methodology to conduct Country Energy Assessments using MARKAL-MACRO is discussed.
Stuart, J.G.; Wright, A.D.; Butterfield, C.P.
1996-10-01T23:59:59.000Z
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.
Weeks, Eric R.
this behavior. The mode coupling theory [1] describes many aspects of dynamical behavior at high T- stood as a simple activated bondbreaking process. Here, we perform molecular dynamics (MD) simula- tionsSpatially Heterogeneous Dynamics and Dynamic Facilitation in a Model of Viscous Silica Michael
Catholic University of Chile (Universidad Católica de Chile)
on dynamic programming that optimizes and validates the bid prices strategies for each power plant in a hydro 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
Friction in a Model of Hamiltonian Dynamics
Juerg Froehlich; Zhou Gang; Avy Soffer
2011-11-01T23:59:59.000Z
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.
DYNAMICAL MODEL OF AN EXPANDING SHELL
Pe'er, Asaf [Harvard-Smithsonian Center for Astrophysics, MS-51, 60 Garden Street, Cambridge, MA 02138 (United States)
2012-06-10T23:59:59.000Z
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.
Radionuclide release rates from spent fuel for performance assessment modeling
Curtis, D.B.
1994-11-01T23:59:59.000Z
In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments.
Fuel cycle assessment: A compendium of models, methodologies, and approaches
Not Available
1994-07-01T23:59:59.000Z
The purpose of this document is to profile analytical tools and methods which could be used in a total fuel cycle analysis. The information in this document provides a significant step towards: (1) Characterizing the stages of the fuel cycle. (2) Identifying relevant impacts which can feasibly be evaluated quantitatively or qualitatively. (3) Identifying and reviewing other activities that have been conducted to perform a fuel cycle assessment or some component thereof. (4) Reviewing the successes/deficiencies and opportunities/constraints of previous activities. (5) Identifying methods and modeling techniques/tools that are available, tested and could be used for a fuel cycle assessment.
Solar Resource Assessment: Databases, Measurements, Models, and Information Sources (Fact Sheet)
Not Available
2008-10-01T23:59:59.000Z
Fact sheet for Solar Resource Assessment Workshop, Denver CO, Oct 29, 2008: ?Solar Resource Assessment Databases, Measurements, Models, and Information Sources
A Markov model of land use dynamics
Campillo, Fabien; Raherinirina, Angelo; Rakotozafy, Rivo
2011-01-01T23:59:59.000Z
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.
A dynamic model of industrial energy demand in Kenya
Haji, S.H.H. [Gothenburg Univ. (Sweden)
1994-12-31T23:59:59.000Z
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.
Modelling of Remediation Technologies at the Performance Assessment Level
Parton, N.J.; Paksy, A.; Eden, L.; Trivedi, D.P. [Nexia Solutions Limited, Hinton House, Risley, Warrington, Cheshire, UK, WA (United States)
2008-07-01T23:59:59.000Z
This paper presents approaches to modelling three different remediation technologies that are designed to support site operators during their assessment of remediation options for the management of radioactively contaminated land on nuclear licensed sites in the UK. The three selected technologies were soil washing, permeable reactive barrier and in-situ stabilisation. The potential exists to represent electrokinetics in the future. These technologies were chosen because it was considered that enough information already existed for site operators to assess mature technologies such as soil dig and disposal and groundwater pump and treat. Using the software code GoldSim, the models have been designed to allow site operators to make both a reasonable scoping level assessment of the viability of treatment and understand the cost-benefits of each technology. For soil washing, a standard soil leaching technique was simulated whereby the soil is separated into fines and oversize particles, and subsequently a chemical reagent is used to strip contamination off the soil. The cost benefit of this technology in terms of capital costs for the plant and materials, operational costs and waste disposal costs can also be assessed. The permeable reactive barrier (PRB) model can represent either a continuous wall or a funnel and gate system. The model simulates the transport of contaminants through the reactive material contained in the PRB. The outputs from the model include concentration of contaminants in the groundwater flow downstream of the PRB, mass of contaminants retained by the PRB, total mass and volume of waste and the various costs associated with the PRB remediation technology. The in-situ stabilisation (ISS) model has the capability to represent remediation by the addition of reagents that immobilise contaminated soil. The model simulates the release of contaminants from the treated soil over time. Performance is evaluated by comparison of the mass of contaminants retained and released to the area outside the treatment zone. Other outputs include amount of spoil generated (to be treated as waste) and the costs associated with the application of the ISS technology. These models are aimed to help users select a technology or technologies that are potentially suitable for a particular site. It is anticipated that they will prompt the user to undertake more detailed assessments to tailor the selected technology to their site specific circumstances and contaminated land conditions. (author)
Modeling Infection with Multi-agent Dynamics
Dong, Wen
2012-01-01T23:59:59.000Z
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 ...
Modeling of Alpine Atmospheric Dynamics II
Gohm, Alexander
: mesoscale convective system 17-18 April 2004: Sierra hydraulic jump case 21 January 2005: the "Universiade) Results and discussion (synoptic scale overview, mesoscale structure, comparison of model and measurements
Generative modeling of dynamic visual scenes
Lin, Dahua, Ph. D. Massachusetts Institute of Technology
2012-01-01T23:59:59.000Z
Modeling visual scenes is one of the fundamental tasks of computer vision. Whereas tremendous efforts have been devoted to video analysis in past decades, most prior work focuses on specific tasks, leading to dedicated ...
Modeling emotion dynamics in intelligent agents
Seif El-Nasr, Magy
1998-01-01T23:59:59.000Z
OF SIMULATION AND RESULTS . . . . . . . . . . . D. CONTRIBUTIONS 7. STRUCTURE OF THE THESIS 1 3 4 7 9 13 13 15 18 18 19 11 PREVIOUS WORK . . 20 1. PSYCHOLOGICAL MODELS . A. MOTIVATIONAL STATES . B. APPRAISAL MODELS OF EMOTIONS... all the needs and urges, while the mind is the heart of the rational thinking process [9]. After three centuries, new theories of emotions were established. By 1884, William James [15] published his article "What is Emotion?" At that time...
Johnson, Chris
to assess the nation's military preparedness. However, risk management is not a panacea for the problemsThe Paradoxes of Military Risk Assessment: Will the Enterprise Risk Assessment Model, Composite Risk Management and Associated Techniques Provide the Predicted Benefits? Chris. W. Johnson, Glasgow
Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.; Krupka, Kenneth M.; Sasser, Lyle B.
2003-07-20T23:59:59.000Z
A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants, including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.
Models of Receptive Field Dynamics in Visual Cortex
1999-01-01T23:59:59.000Z
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...
CSAW: a dynamical model of protein folding
Kerson Huang
2006-01-12T23:59:59.000Z
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.
Kinetic Modeling and Assessment of Lime Pretreatment of Poplar Wood
Sierra Ramirez, Rocio
2012-02-14T23:59:59.000Z
biomass is one of the most promising feedstocks for producing biofuels through fermentation processes. Among lignocellulose choices, poplar wood is appealing because of high energy potential, above-average carbon mitigation potential, fast growth... KINETIC MODELING AND ASSESSMENT OF LIME PRETREATMENT OF POPLAR WOOD A Dissertation by ROCIO SIERRA RAMIREZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...
UNCORRECTEDPROOF Parameter identification in dynamical models of
Timmer, Jens
only biogas production rate was 14 measured which complicates the analysis considerably. We show product is methane. In recent years more and more complex mathematical models of anaerobic 26 digestion. Yet in many ex- 36 perimental settings only biogas production rate data is available which complicates
Green Algae as Model Organisms for Biological Fluid Dynamics
Goldstein, Raymond E
2014-01-01T23:59:59.000Z
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...
Green Algae as Model Organisms for Biological Fluid Dynamics
Raymond E. Goldstein
2014-09-08T23:59:59.000Z
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.
Dynamic crack initiation toughness : experiments and peridynamic modeling.
Foster, John T.
2009-10-01T23:59:59.000Z
This is a dissertation on research conducted studying the dynamic crack initiation toughness of a 4340 steel. Researchers have been conducting experimental testing of dynamic crack initiation toughness, K{sub Ic}, for many years, using many experimental techniques with vastly different trends in the results when reporting K{sub Ic} as a function of loading rate. The dissertation describes a novel experimental technique for measuring K{sub Ic} in metals using the Kolsky bar. The method borrows from improvements made in recent years in traditional Kolsky bar testing by using pulse shaping techniques to ensure a constant loading rate applied to the sample before crack initiation. Dynamic crack initiation measurements were reported on a 4340 steel at two different loading rates. The steel was shown to exhibit a rate dependence, with the recorded values of K{sub Ic} being much higher at the higher loading rate. Using the knowledge of this rate dependence as a motivation in attempting to model the fracture events, a viscoplastic constitutive model was implemented into a peridynamic computational mechanics code. Peridynamics is a newly developed theory in solid mechanics that replaces the classical partial differential equations of motion with integral-differential equations which do not require the existence of spatial derivatives in the displacement field. This allows for the straightforward modeling of unguided crack initiation and growth. To date, peridynamic implementations have used severely restricted constitutive models. This research represents the first implementation of a complex material model and its validation. After showing results comparing deformations to experimental Taylor anvil impact for the viscoplastic material model, a novel failure criterion is introduced to model the dynamic crack initiation toughness experiments. The failure model is based on an energy criterion and uses the K{sub Ic} values recorded experimentally as an input. The failure model is then validated against one class of problems showing good agreement with experimental results.
PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment
Jordan, J. M.; Flach, G. P.; Westbrook, M. L.
2012-08-31T23:59:59.000Z
Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.
A Dynamical Model of Plasma Turbulence in the Solar Wind
Howes, G G
2015-01-01T23:59:59.000Z
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...
Fant, C.A.
This paper describes the use of the CliCrop model in the context of climate change general assessment
Model Independent Analysis of Beam Centroid Dynamics in Accelerators
Wang, Chun-xi
2003-04-21T23:59:59.000Z
Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map measurements and shows that it is possible to measure the Poincare section map (in terms of Taylor series) of a circular accelerator to a surprisingly high order and accuracy based on present BPM technology. MIA can overcome the inherent limit of BPM resolution. Nonlinear map measurements will advance understanding of the beam dynamics of a ring.
Wind Energy Applications of Unified and Dynamic Turbulence Models
Heinz, Stefan
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
Non-perturbative Dynamical Decoupling Control: A Spin Chain Model
Zhao-Ming Wang; Lian-Ao Wu; Jun Jing; Bin Shao; Ting Yu
2012-03-24T23:59:59.000Z
This paper considers a spin chain model by numerically solving the exact model to explore the non-perturbative dynamical decoupling regime, where an important issue arises recently (J. Jing, L.-A. Wu, J. Q. You and T. Yu, arXiv:1202.5056.). Our study has revealed a few universal features of non-perturbative dynamical control irrespective of the types of environments and system-environment couplings. We have shown that, for the spin chain model, there is a threshold and a large pulse parameter region where the effective dynamical control can be implemented, in contrast to the perturbative decoupling schemes where the permissible parameters are represented by a point or converge to a very small subset in the large parameter region admitted by our non-perturbative approach. An important implication of the non-perturbative approach is its flexibility in implementing the dynamical control scheme in a experimental setup. Our findings have exhibited several interesting features of the non-perturbative regimes such as the chain-size independence, pulse strength upper-bound, noncontinuous valid parameter regions, etc. Furthermore, we find that our non-perturbative scheme is robust against randomness in model fabrication and time-dependent random noise.
Multiscale modeling of polystyrene dynamics in different environments
Faller, Roland
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
Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction
Veatch, Michael H.
of approximating functions for the differential cost. The first contribution of this paper is identifying new or piece-wise quadratic. Fluid cost has been used to initialize the value iteration algorithm [5Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction Michael H
Model-Driven Dynamic Control of Embedded Wireless Sensor Networks
Agarwal, Pankaj K.
Model-Driven Dynamic Control of Embedded Wireless Sensor Networks Paul G. Flikkema1 , Pankaj K-generation wireless sensor networks may revolution- ize understanding of environmental change by assimilating heteroge of wireless sensor networks is now becoming a mature research field. As a result, the discipline is undergoing
Dynamical Analysis of the Fitzhugh-Nagumo Model
Beer, Randall D.
Dynamical Analysis of the Fitzhugh-Nagumo Model #12;IU/COGS-Q580/Beer This isYour Brain #12;IU/COGS-Q580/Beer Action Potentials Tateno, T., Harsch, A. and Robinson, H.P.C. (2004). Threshold Firing. Neurophysiology 92:2283-2294. #12;IU/COGS-Q580/Beer The Ionic Basis of the Action Potential Delcomyn, F. (1998
A Dynamic Model coupling Photoacclimation and Photoinhibition in Microalgae
Boyer, Edmond
A Dynamic Model coupling Photoacclimation and Photoinhibition in Microalgae Philipp Hartmann1, Andreas Nikolaou2, Beno^it Chachuat2, Olivier Bernard1 Abstract-- Microalgae are often considered a promising al- ternative for production of renewable energy, particularly as a potential producer
Modelling Dynamic Trust with Property Based Attestation in Trusted Platforms
Paris-Sud XI, Université de
Modelling Dynamic Trust with Property Based Attestation in Trusted Platforms Aarthi Nagarajan attestation in trusted computing provides the ability to reason about the state of a platform using integrity attestation by abstracting low level binary values to high level security properties or functions of platforms
LECTURES ON GLAUBER DYNAMICS FOR DISCRETE SPIN MODELS
Transitions 5.1 The SolidonSolid Approximation 5.2 Back to the Ising Model 5.3 Recent Progresses 6. Phase Measures 2.3 Weak and Strong Mixing Conditions 2.4 Mixing properties and bounds on relative densities 3 on the Spectral Gap with Free B.C 6.6 Mixed B.C 6.7 Applications 7. Glauber Dynamics for the Dilute Ising Model 7
Fitting Dynamical Models to Observations of Globular Clusters
Dean E. McLaughlin
2003-02-14T23:59:59.000Z
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.
Russell, Lynn
Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect Corporation for Atmospheric Research, Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA V. Ramaswamy, Paul A. Ginoux, and Larry W. Horowitz Geophysical Fluid Dynamics Laboratory, Princeton, New
California at Irvine, University of
CVSys: A Coordination Framework for Dynamic and Fully Distributed Cardiovascular Modeling and dynamic simulation control. This coordination framework uniquely incorporates attributes of open indigenous and a more integrated system representation. Dynamic simulation control serves to interject new
Gauge turbulence, topological defect dynamics, and condensation in Higgs models
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gasenzer, Thomas [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany); McLerran, Larry [Brookhaven National Laboratory, Physics Department, RIKEN BNL Research Center Upton NY (United States); China Central Normal University, Physics Department, Wuhan (China); Pawlowski, Jan M [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Sexty, Denes [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany)
2014-10-01T23:59:59.000Z
The real-time dynamics of topological defects and turbulent configurations of gauge fields for electric and magnetic confinement are studied numerically within a 2+1D Abelian Higgs model. It is shown that confinement is appearing in such systems equilibrating after a strong initial quench such as the overpopulation of the infrared modes. While the final equilibrium state does not support confinement, metastable vortex defect configurations appearing in the gauge field are found to be closely related to the appearance of physically observable confined electric and magnetic charges. These phenomena are seen to be intimately related to the approach of a non-thermal fixed point of the far-from-equilibrium dynamical evolution, signaled by universal scaling in the gauge-invariant correlation function of the Higgs field. Even when the parameters of the Higgs action do not support condensate formation in the vacuum, during this approach, transient Higgs condensation is observed. We discuss implications of these results for the far-from-equilibrium dynamics of Yang–Mills fields and potential mechanisms of how confinement and condensation in non-Abelian gauge fields can be understood in terms of the dynamics of Higgs models. These suggest that there is an interesting new class of dynamics of strong coherent turbulent gauge fields with condensates.
Gauge turbulence, topological defect dynamics, and condensation in Higgs models
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gasenzer, Thomas; McLerran, Larry; Pawlowski, Jan M.; Sexty, Dénes
2014-10-01T23:59:59.000Z
The real-time dynamics of topological defects and turbulent configurations of gauge fields for electric and magnetic confinement are studied numerically within a 2+1D Abelian Higgs model. It is shown that confinement is appearing in such systems equilibrating after a strong initial quench such as the overpopulation of the infrared modes. While the final equilibrium state does not support confinement, metastable vortex defect configurations appearing in the gauge field are found to be closely related to the appearance of physically observable confined electric and magnetic charges. These phenomena are seen to be intimately related to the approach of a non-thermal fixedmore »point of the far-from-equilibrium dynamical evolution, signaled by universal scaling in the gauge-invariant correlation function of the Higgs field. Even when the parameters of the Higgs action do not support condensate formation in the vacuum, during this approach, transient Higgs condensation is observed. We discuss implications of these results for the far-from-equilibrium dynamics of Yang–Mills fields and potential mechanisms of how confinement and condensation in non-Abelian gauge fields can be understood in terms of the dynamics of Higgs models. These suggest that there is an interesting new class of dynamics of strong coherent turbulent gauge fields with condensates.« less
An Inspector's Assessment of the New Model Safeguards Approach for Enrichment Plants
Curtis, Michael M.
2007-07-31T23:59:59.000Z
This conference paper assesses the changes that are being made to the Model Safeguards Approach for Gas Centrifuge Enrichment Plants.
Methods for Developing Emissions Scenarios for Integrated Assessment Models
Prinn, Ronald [MIT; Webster, Mort [MIT
2007-08-20T23:59:59.000Z
The overall objective of this research was to contribute data and methods to support the future development of new emissions scenarios for integrated assessment of climate change. Specifically, this research had two main objectives: 1. Use historical data on economic growth and energy efficiency changes, and develop probability density functions (PDFs) for the appropriate parameters for two or three commonly used integrated assessment models. 2. Using the parameter distributions developed through the first task and previous work, we will develop methods of designing multi-gas emission scenarios that usefully span the joint uncertainty space in a small number of scenarios. Results on the autonomous energy efficiency improvement (AEEI) parameter are summarized, an uncertainty analysis of elasticities of substitution is described, and the probabilistic emissions scenario approach is presented.
Donovan, Amy R.; Oppenheimer, Clive
2014-11-27T23:59:59.000Z
(Stirling, 151 2008). For Massey, space is dynamic: it must be thought of in relation to time. It resists 152 enclosure in a model. In considering geographical models in light of this, O’Sullivan (2004) 153 suggests that “it is vital that modelling... , 215 noting the presence of social, psychological and geographical uncertainties (see also Stirling, 216 2007, 2008; Wynne, 1992; Jasanoff, 2004, 2005). Understanding the complex ways in which 217 uncertainty is generated is critical in appreciating...
A dynamical symmetry breaking model in Weyl space
A. Feoli; W. R. Wood; G. Papini
1998-05-11T23:59:59.000Z
The dynamical process following the breaking of Weyl geometry to Riemannian geometry is considered by studying the motion of de Sitter bubbles in a Weyl vacuum. The bubbles are given in terms of an exact, spherically symmetric thin shell solution to the Einstein equations in a Weyl-Dirac theory with a time-dependent scalar field of the form beta = f(t)/r. The dynamical solutions obtained lead to a number of possible applications. An important feature of the thin shell model is the manner in which beta provides a connection between the interior and exterior geometries since information about the exterior geometry is contained in the boundary conditions for beta.
Gaussian Process Model for Collision Dynamics of Complex Molecules
Cui, Jie
2015-01-01T23:59:59.000Z
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 ...
Mathematical Modeling of Microbial Community Dynamics: A Methodological Review
Song, Hyun-Seob; Cannon, William R.; Beliaev, Alex S.; Konopka, Allan
2014-10-17T23:59:59.000Z
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.
HVAC Modeling for Cost of Ownership Assessment in Biotechnology & Drugs Manufacturing
Broomes, Peter; Dornfeld, David A
2003-01-01T23:59:59.000Z
2000 Broomes, Peter. , “HVAC Modeling for Cost of Ownership2000 Broomes, Peter. , “HVAC Results Comparison”, April,HVAC Modeling for Cost of Ownership Assessment in
Model for dynamic self-assembled magnetic surface structures.
Belkin, M.; Glatz, A.; Snezhko, A.; Aranson, I. S.; Materials Science Division; Northwestern Univ.
2010-07-07T23:59:59.000Z
We propose a first-principles model for the dynamic self-assembly of magnetic structures at a water-air interface reported in earlier experiments. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended at a water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snakelike structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids.
Modeling Dynamics in the Central Regions of Disk Galaxies
Isaac Shlosman
2004-12-07T23:59:59.000Z
The central regions of disk galaxies are hosts to supermassive black holes whose masses show a tight correlation with the properties of surrounding stellar bulges. While the exact origin of this dependency is not clear, it can be related to the very basic properties of dark matter halos and the associated gas and stellar dynamics in the central kpc of host galaxies. In this review we discuss some of the recent developments in modeling the wide spectrum of dynamical processes which can be affiliated with the above phenomena, such as the structure of molecular tori in AGN, structure formation in triaxial halos, and dissipative and non-dissipative dynamics in nested bar systems, with a particular emphasis on decoupling of gaseous nuclear bars. We also briefly touch on the subject of fueling the nuclear starbursts and AGN.
Einarsson, Baldvin; Birnir, Bjorn; Sigurðsson, Sven Þ.
2010-01-01T23:59:59.000Z
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
Performance Assessment of Prediction In Dynamic Environments (PRIDE) in Manufacturing Environments
Kootbally, Zeid [National Institute of Standards and Technology (NIST)] [National Institute of Standards and Technology (NIST); Schlenoff, Craig [National Institute of Standards and Technology (NIST)] [National Institute of Standards and Technology (NIST); Madhavan, Raj [ORNL] [ORNL
2009-01-01T23:59:59.000Z
This paper describes PRIDE (Prediction in Dynamic Environments), a multi-resolution and hierarchical framework. PRIDE was developed as a test bed to assess the performance of autonomous vehicles in the presence of moving objects in a simulated environment. By simulating scenarios in which moving objects are prevalent, a designer of an autonomous vehicle can test the performance of their path planning and collision avoidance algorithms without having to immerse the vehicle in the physical world. This framework supports the prediction of the future location of moving objects at various levels of resolution, thus providing prediction information at the frequency and level of abstraction necessary for planners at different levels within the hierarchy. Previous works have demonstrated the reliability of PRIDE to simulate on-road traffic situations with multiple vehicles. To provide realistic scenarios, PRIDE integrates a level of situation awareness of how other vehicles in the environment are expected to behave considering the situation in which the vehicles find themselves in. In recent efforts, the PRIDE framework has been extended to consider production logistics in dynamic manufacturing environment while focusing on the scheduling of material transportation system. To demonstrate the characteristics of the PRIDE framework, this paper illustrates real-time navigation of Automated Guided Vehicles (AGVs) at different locations in a dynamic manufacturing environment. Moreover, using the high-fidelity physics?based framework for the Unified System for Automation and Robot Simulation (USARSim), this paper analyzes the performance of the PRIDE framework on a set of realistic scenarios.
Dynamic Absorption Model for Off-Gas Separation
Veronica J. Rutledge
2011-07-01T23:59:59.000Z
Modeling and simulations will aid in the future design of U.S. advanced reprocessing plants for the recovery and recycle of actinides in used nuclear fuel. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, a rate based, dynamic absorption model is being developed in gPROMS software. Inputs include liquid and gas stream constituents, column properties, liquid and gas phase reactions, number of stages, and inlet conditions. It simulates multiple component absorption with countercurrent flow and accounts for absorption by mass transfer and chemical reaction. The assumption of each stage being a discrete well-mixed entity was made. Therefore, the model is solved stagewise. The simulation outputs component concentrations in both phases as a function of time from which the rate of absorption is determined. Temperature of both phases is output as a function of time also. The model will be used able to be used as a standalone model in addition to in series with other off-gas separation unit operations. The current model is being generated based on NOx absorption; however, a future goal is to develop a CO2 specific model. The model will have the capability to be modified for additional absorption systems. The off-gas models, both adsorption and absorption, will be made available via the server or web for evaluation by customers.
Dynamics of Matter in a Compactified Kaluza-Klein Model
Valentino Lacquaniti; Giovanni Montani
2009-02-10T23:59:59.000Z
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.
Model of a deterministic detector and dynamical decoherence
Lee, Jae Weon; Shepelyansky, Dima L. [Laboratoire de Physique Theorique, UMR 5152 du CNRS, Univ. P. Sabatier, 31062 Toulouse Cedex 4 (France); Averin, Dmitri V. [Department of Physics, University of Stony Brook, SUNY, Stony Brook, New York 11794 (United States); Benenti, Giuliano [Center for Nonlinear and Complex Systems, Universita degli Studi dell'Insubria and Istituto Nazionale per la Fisica della Materia, Unita di Como, Via Valleggio 11, 22100 Como (Italy)
2005-07-15T23:59:59.000Z
We discuss a deterministic model of detector coupled to a two-level system (a qubit). The detector is a quasiclassical object whose dynamics is described by the kicked rotator Hamiltonian. We show that in the regime of quantum chaos the detector acts as a chaotic bath and induces decoherence of the qubit. We discuss the dephasing and relaxation rates and demonstrate that the main features of single-qubit decoherence due to a heat bath can be reproduced by our fully deterministic dynamical model. Moreover, we show that, for strong enough qubit-detector coupling, the dephasing rate is given by the rate of exponential instability of the detector's dynamics, that is, by the Lyapunov exponent of classical motion. Finally, we discuss the measurement in the regimes of strong and weak qubit-detector coupling. For the case of strong coupling the detector performs a measurement of the up/down state of the qubit. In the case of weak coupling, due to chaos, the dynamical evolution of the detector is strongly sensitive to the state of the qubit. However, in this case it is unclear how to extract a signal from any measurement with a coarse-graining in the phase space on a size much larger than the Planck cell.
Keratin Dynamics: Modeling the Interplay between Turnover and Transport
Stephanie Portet; Anotida Madzvamuse; Andy Chung; Rudolf E. Leube; Reinhard Windoffer
2015-04-01T23:59:59.000Z
Keratin are among the most abundant proteins in epithelial cells. Functions of the keratin network in cells are shaped by their dynamical organization. Using a collection of experimentally-driven mathematical models, different hypotheses for the turnover and transport of the keratin material in epithelial cells are tested. The interplay between turnover and transport and their effects on the keratin organization in cells are hence investigated by combining mathematical modeling and experimental data. Amongst the collection of mathematical models considered, a best model strongly supported by experimental data is identified. Fundamental to this approach is the fact that optimal parameter values associated with the best fit for each model are established. The best candidate among the best fits is characterized by the disassembly of the assembled keratin material in the perinuclear region and an active transport of the assembled keratin. Our study shows that an active transport of the assembled keratin is required to explain the experimentally observed keratin organization.
Jeffrey C. JOe; Ronald L. Boring
2014-06-01T23:59:59.000Z
Probabilistic Risk Assessment (PRA) and Human Reliability Assessment (HRA) are important technical contributors to the United States (U.S.) Nuclear Regulatory Commission’s (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial NPPs in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. There are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating HEPs. This paper describes research that has the objective to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.
Dynamical Wave Function Collapse Models in Quantum Measure Theory
Fay Dowker; Yousef Ghazi-Tabatabai
2008-05-15T23:59:59.000Z
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.
Dynamic ModelingDynamic Modeling the Electric Power Networkthe Electric Power Network
Oro, Daniel
at the National Energy Modeling System/Annual Energy Outlook Conference, Washington, DC, March 10, 2003] #12
Best practices for system dynamics model design and construction with powersim studio.
Malczynski, Leonard A.
2011-06-01T23:59:59.000Z
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.
Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits
Stryk, Oskar von
Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control model and the algorithm for evaluating the dynamics. The formulation of the optimal control problem
Learning Multiple Models of Non-Linear Dynamics for Control under Varying Contexts
Vijayakumar, Sethu
Learning Multiple Models of Non-Linear Dynamics for Control under Varying Contexts Georgios Petkos for adaptive motor control exist which learn the system's inverse dynamics online and use this single model;II Command Context 1 Context 2 Dynamics models Context n Control Learning Commands Switch / Mix
AIAA 2001-2126 DYNAMICAL MODELS FOR CONTROL OF CAVITY OSCILLATIONS
Dabiri, John O.
AIAA 2001-2126 DYNAMICAL MODELS FOR CONTROL OF CAVITY OSCILLATIONS Clarence W. Rowley Tim Colonius have used an explicit dynamical model for control design, or analysis of performance or robustness, CA 91125 Abstract We investigate nonlinear dynamical models for self- sustained oscillations
Learning Multiple Models of Non-Linear Dynamics for Control under Varying Contexts
Toussaint, Marc
Learning Multiple Models of Non-Linear Dynamics for Control under Varying Contexts Georgios Petkos for adaptive motor control exist which learn the system's inverse dynamics online and use this single model version - to appear in ICANN 2006 #12;II Command Context 1 Context 2 Dynamics models Context n Control
Load estimation and control using learned dynamics models Georgios Petkos and Sethu Vijayakumar
Vijayakumar, Sethu
Load estimation and control using learned dynamics models Georgios Petkos and Sethu Vijayakumar with their robustness in light of imperfect, intermediate dynamic models. I. INTRODUCTION Adaptive control the learned dynamics for control. In Section IV, we see how from a set of learned models with known inertial
Direct Modeling of Envelope Dynamics in Resonant Inverters Yan Yin, Regan Zane, Robert Erickson
to facilitate optimized controller design. Several approaches are available to model the envelope dynamicsDirect Modeling of Envelope Dynamics in Resonant Inverters Yan Yin, Regan Zane, Robert Erickson- This paper provides a direct dynamic modeling approach for envelope signals in resonant inverters driven
Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities
Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina
2012-09-01T23:59:59.000Z
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.
A Nonlocal Peridynamic Plasticity Model for the Dynamic Flow and Fracture of Concrete.
Vogler, Tracy; Lammi, Christopher James
2014-10-01T23:59:59.000Z
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.
User Guide for PV Dynamic Model Simulation Written on PSCAD Platform
Muljadi, E.; Singh, M.; Gevorgian, V.
2014-11-01T23:59:59.000Z
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.
Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models
Bath, University of
Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models 1 Introduction The potential detrimental e#ects of ambient air pollution is a major issue in public (2004)). Large multicity studies such as `Air pollution and health: a European approach' (APHEA
Code description: A dynamic modelling strategy for Bayesian computer model emulation
West, Mike
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": Â· "design1.dat": this file2.dat": this file contains the 60 validation runs. The Matlab code is provided under the directory
A spectral transform dynamical core option within the Community Atmosphere Model (CAM4)
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
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.
Coles, Garill A.; Brothers, Alan J.; Gastelum, Zoe N.; Olson, Jarrod; Thompson, Sandra E.
2009-10-26T23:59:59.000Z
The Utility of Social Modeling for Proliferation Assessment project (PL09-UtilSocial) investigates the use of social and cultural information to improve nuclear proliferation assessments, including nonproliferation assessments, Proliferation Resistance (PR) assessments, safeguards assessments, and other related studies. These assessments often use and create technical information about a host State and its posture towards proliferation, the vulnerability of a nuclear energy system (NES) to an undesired event, and the effectiveness of safeguards. This objective of this project is to find and integrate social and technical information by explicitly considering the role of cultural, social, and behavioral factors relevant to proliferation; and to describe and demonstrate if and how social science modeling has utility in proliferation assessment. This report describes a modeling approach and how it might be used to support a location-specific assessment of the PR assessment of a particular NES. The report demonstrates the use of social modeling to enhance an existing assessment process that relies on primarily technical factors. This effort builds on a literature review and preliminary assessment performed as the first stage of the project and compiled in PNNL-18438. [ T his report describes an effort to answer questions about whether it is possible to incorporate social modeling into a PR assessment in such a way that we can determine the effects of social factors on a primarily technical assessment. This report provides: 1. background information about relevant social factors literature; 2. background information about a particular PR assessment approach relevant to this particular demonstration; 3. a discussion of social modeling undertaken to find and characterize social factors that are relevant to the PR assessment of a nuclear facility in a specific location; 4. description of an enhancement concept that integrates social factors into an existing, technically based nuclear facility assessment; 5. a discussion of a way to engage with the owners of the PR assessment methodology to assess and improve the enhancement concept; 6. a discussion of implementation of the proposed approach, including a discussion of functionality and potential users; and 7. conclusions from the research. This report represents technical deliverables for the NA-22 Simulations, Algorithms, and Modeling program. Specifically this report is the Task 2 and 3 deliverables for project PL09-UtilSocial.
System vulnerability as a concept to assess power system dynamic security
Fouad, A.A.; Qin Zhou; Vittal, V. (Iowa State Univ., Ames, IA (United States))
1994-05-01T23:59:59.000Z
The concept of system vulnerability is introduced as a new framework for power system dynamic security assessment. This new concept combines information on the level of security and its trend with changing system condition. In this paper the transient energy function (TEF) method is used as a tool of analysis. The energy margin [Delta]V is used as an indicator of the level of security, and its sensitivity ([partial derivative][Delta]V/[partial derivative]p) to a changing system parameter p as an indicator of its trend. The thresholds for acceptable levels of the security indicator ([Delta]V) and its trend ([partial derivative][Delta]V/[partial derivative]p) are related to the stability limits of a critical system parameter. A method is proposed to determine these thresholds using heuristic techniques derived from operating practices and policies for a change in plant generation. Results from the IEEE 50 generator test system are presented to illustrate the procedure.
Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)
Burkett, Michael W [Los Alamos National Laboratory; Clancy, Sean P [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
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.
Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics
Persson, Rasmus A. X.; Chu, Jhih-Wei, E-mail: jwchu@nctu.edu.tw [Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Voulgarakis, Nikolaos K. [Department of Mathematics, Washington State University, Richland, Washington 99372 (United States)
2014-11-07T23:59:59.000Z
Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ? in coupling to the other equations of FHD. The resulting ?-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ?-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ?-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 Å, the ?-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.
Computational fluid dynamic modeling of fluidized-bed polymerization reactors
Rokkam, Ram [Ames Laboratory
2012-11-02T23:59:59.000Z
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.
Nucleon-nucleon interaction in the chromodielectric soliton model: Dynamics
Pepin, S.; Stancu, F. [Universite de Liege, Institut de Physique B.5, Sart-Tilman, B-4000 Liege 1 (Belgium)] [Universite de Liege, Institut de Physique B.5, Sart-Tilman, B-4000 Liege 1 (Belgium); Koepf, W. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 69978 Tel Aviv (Israel)] [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 69978 Tel Aviv (Israel); Wilets, L. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)
1996-03-01T23:59:59.000Z
The present work is an extension of a previous study of the nucleon-nucleon interaction based on the chromodielectric soliton model. The former approach was static, leading to an adiabatic potential. Here we perform a dynamical study in the framework of the generator coordinate method. In practice we derive an approximate Hill-Wheeler differential equation and obtain a local nucleon-nucleon potential as a function of a mean generator coordinate. This coordinate is related to an effective separation distance between the two nucleons by a Fujiwara transformation. This latter relationship is especially useful in studying the quark substructure of light nuclei. We investigate the explicit contribution of the one-gluon exchange part of the six-quark Hamiltonian to the nucleon-nucleon potential, and we find that the dynamics are responsible for a significant part of the short-range {ital N}-{ital N} repulsion. {copyright} {ital 1996 The American Physical Society.}
Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance Models
Mountziaris, T. J.
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
Fayer, Michael D.
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
Explorations in combining cognitive models of individuals and system dynamics models of groups.
Backus, George A.
2008-07-01T23:59:59.000Z
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.
Mechanical reaction-diffusion model for bacterial population dynamics
Ngamsaad, Waipot
2015-01-01T23:59:59.000Z
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.
A model of riots dynamics: shocks, diffusion and thresholds
Berestycki, Henri; Rodriguez, Nancy
2015-01-01T23:59:59.000Z
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.
The Third State of the Schelling Model of Residential Dynamics
Benenson, Itzhak
2009-01-01T23:59:59.000Z
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...
Model for Aggregated Water Heater Load Using Dynamic Bayesian Networks
Vlachopoulou, Maria; Chin, George; Fuller, Jason C.; Lu, Shuai; Kalsi, Karanjit
2012-07-19T23:59:59.000Z
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.
Paris-Sud XI, Université de
24 Automate Monitoring System for the Dynamics of Lands Based on Aerial Photos Assessed by Artificial Neural Techniques Ioan Ilean Department of Computer Science "1Decembrie 1918" University Alba. In this project an application of artificial neural networks to human-centered earth science information
Li, Yangmin
Dynamic 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 manipulator, neural-fuzzy control, nonholonomic. 1. INTRODUCTION Intelligent and autonomous mobile
Ice sheets and their dynamics Continuum thermo-mechanical model of a glacier
Cerveny, Vlastislav
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
Polymer dynamics in repton model at large fields Anatoly B. Kolomeisky
Polymer dynamics in repton model at large fields Anatoly B. Kolomeisky Department of Chemistry, Poland Received 22 October 2003; accepted 26 January 2004 Polymer dynamics at large fields in Rubinstein simple exclusion models are used to analyze the reptation dynamics of polymers. It is found
A LUMPED-PARAMETER DYNAMIC MODEL OF A THERMAL REGENERATOR FOR FREE-PISTON STIRLING ENGINES
Barth, Eric J.
A LUMPED-PARAMETER DYNAMIC MODEL OF A THERMAL REGENERATOR FOR FREE-PISTON STIRLING ENGINES Mark the mass flow, piston dynamics, and control volume behavior inside a free-piston Stirling engine. A new model for a Stirling engine thermal regenerator that incorporates a dynamically changing temperature
Assessment of a Molecular Diffusion Model in MELCOR
Chang OH; Richard Moore
2005-06-01T23:59:59.000Z
The MELCOR (version 1.8.5) [1] computer code with INEEL revisions is being improved for the analysis of very high temperature gas-cooled reactors [2]. Following a loss-of-coolant accident, flow through the reactor vessel may initially stagnate due to a non-uniform concentration of helium and air. However, molecular diffusion will eventually result in a uniform concentration of air and helium. The differences in fluid temperatures within the reactor vessel will then result in the establishment of a natural circulation flow that can supply significant amounts of air to the reactor core. The heat released by the resulting oxidation of graphite in the reactor core has the potential to increase the peak fuel temperature. In order to analyze the effects of oxidation on the response of the reactor during accidents, a molecular diffusion model was added to MELCOR. The model is based on Fick's Second Law for spatially uniform pressure and temperature. This paper describes equimolal counter diffusion experiments in a two bulb diffusion cell and the results of the assessment calculations.
A simple microscopic model for the dynamics of adhesive failure
Dominic Vella; L. Mahadevan
2005-12-27T23:59:59.000Z
We consider a microscopic model for the failure of soft adhesives in tension based on ideas of bond rupture under dynamic loading. Focusing on adhesive failure under loading at constant velocity, we demonstrate that bi-modal curves of stress against strain may occur due to effects of finite polymer chain or bond length and characterise the loading conditions under which such bi-modal behaviour is observed. The results of this analysis are in qualitative agreement with experiments performed on unconfined adhesives in which failure does not occur by cavitation.
Validation of DWPF MOG dynamics model -- Phase 1
Choi, A.S.
1996-09-23T23:59:59.000Z
The report documents the results of a study to validate the DWPF melter off-gas system dynamics model using the data collected during the Waste Qualification Runs in 1995. The study consisted of: (1) calibration of the model using one set of melter idling data, (2) validation of the calibrated model using three sets of steady feeding and one set of transient data, and (3) application of the validated model to simulate the melter overfeeding incident which took place on 7/5.95. All the controller tuning constants and control logic used in the validated model are identical to those used in the DCS in 1995. However, the model does not reflect any design and/or operational changes made in 1996 to alleviate the glass pouring problem. Based on the results of the overfeeding simulation, it is concluded that the actual feed rates during that incident were about 2.75 times the indicated readings and that the peak concentration of combustible gases remained below 15% of the lower flammable limit during the entire one-hour duration.
Designability, thermodynamic stability, and dynamics in protein folding: A lattice model study
Levine, Alex J.
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
Computational Fluid Dynamics Modeling of the John Day Dam Tailrace
Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C.; Serkowski, John A.
2010-07-08T23:59:59.000Z
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.
Modeling and Risk Assessment of CO{sub 2} Sequestration at the Geologic-basin Scale
Juanes, Ruben
2013-08-31T23:59:59.000Z
Objectives. The overall objective of this proposal was to develop tools for better understanding, modeling and risk assessment of CO{sub 2} permanence in geologic formations at the geologic basin scale. The main motivation was that carbon capture and storage (CCS) will play an important role as a climate change mitigation technology only if it is deployed at scale of gigatonne per year injections over a period of decades. Continuous injection of this magnitude must be understood at the scale of a geologic basin. Specifically, the technical objectives of this project were: (1) to develop mathematical models of capacity and injectivity at the basin scale; (2) to apply quantitative risk assessment methodologies that will inform on CO{sub 2} permanence; (3) to apply the models to geologic basins across the continental United States. These technical objectives go hand-in-hand with the overarching goals of: (1) advancing the science for deployment of CCS at scale; and (2) contributing to training the next generation of scientists and engineers that will implement and deploy CCS in the United States and elsewhere. Methods. The differentiating factor of this proposal was to perform fundamental research on migration and fate of CO{sub 2} and displaced brine at the geologic basin scale. We developed analytical sharp-interface models of the evolution of CO{sub 2} plumes over the duration of injection (decades) and after injection (centuries). We applied the analytical solutions of CO{sub 2} plume migration and pressure evolution to specific geologic basins, to estimate the maximum footprint of the plume, and the maximum injection rate that can be sustained during a certain injection period without fracturing the caprock. These results have led to more accurate capacity estimates, based on fluid flow dynamics, rather than ad hoc assumptions of an overall “efficiency factor.” We also applied risk assessment methodologies to evaluate the uncertainty in our predictions of storage capacity and leakage rates. This was possible because the analytical mathematical models provide ultrafast forward simulation and they contain few parameters. Impact. The project has been enormously successful both in terms of its scientific output (journal publications) as well as impact in the government and industry. The mathematical models and uncertainty quantification methodologies developed here o?er a physically-based approach for estimating capacity and leakage risk at the basin scale. Our approach may also facilitate deployment of CCS by providing the basis for a simpler and more coherent regulatory structure than an “individual-point-of-injection” permitting approach. It may also lead to better science-based policy for post-closure design and transfer of responsibility to the State.
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
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.
Zhang, Xuesong; Izaurralde, Roberto C.; Arnold, Jeffrey; Williams, Jimmy R.; Srinivasan, Raghavan
2013-10-01T23:59:59.000Z
Climate change is one of the most compelling modern issues and has important implications for almost every aspect of natural and human systems. The Soil and Water Assessment Tool (SWAT) model has been applied worldwide to support sustainable land and water management in a changing climate. However, the inadequacies of the existing carbon algorithm in SWAT limit its application in assessing impacts of human activities on CO2 emission, one important source of greenhouse gases (GHGs) that traps heat in the earth system and results in global warming. In this research, we incorporate a revised version of the CENTURY carbon model into SWAT to describe dynamics of soil organic matter (SOM)- residue and simulate land-atmosphere carbon exchange.
Learning Multiple Models of Non-Linear Dynamics for Control under Varying Contexts
Petkos, Georgios; Toussaint, Marc; Vijayakumar, Sethu
For stationary systems, efficient techniques for adaptive motor control exist which learn the system’s inverse dynamics online and use this single model for control. However, in realistic domains the system dynamics often ...
Griffith, Daniel Todd
2005-02-17T23:59:59.000Z
The main objective of this work is to demonstrate some new computational methods for estimation, optimization and modeling of dynamical systems that use automatic differentiation. Particular focus will be upon dynamical ...
Examination of temporal DDT trends in Lake Erie fish communities using dynamic linear modeling
Arhonditsis, George B.
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
Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taiwan (China)] [Hydrotech Research Institute, National Taiwan University, Taiwan (China); Yu, Charley; Cheng, Jing-Jy; Kamboj, Sunita; Gnanapragasam, Emmanuel [Argonne National Laboratory, Argonne, IL 60439 (United States)] [Argonne National Laboratory, Argonne, IL 60439 (United States); Liu, Chen-Wuing [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China)] [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)] [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)
2013-07-01T23:59:59.000Z
Performance assessments are crucial steps for the long-term radiological safety requirements of low-level waste (LLW) disposal facility. How much concentration of radionuclides released from the near-field to biosphere and what radiation exposure levels of an individual can influence on the satisfactory performance of the LLW disposal facility and safety disposal environment. Performance assessment methodology for the radioactive waste disposal consists of the reactive transport modeling of safety-concerned radionuclides released from the near-field to the far-field, and the potential exposure pathways and the movements of radionuclides through the geosphere, biosphere and man of which the accompanying dose. Therefore, the integration of hydrogeochemical transport model and dose assessment code, HYDROGEOCHEM code and RESRAD family of codes is imperative. The RESRAD family of codes such as RESRAD-OFFSITE computer code can evaluate the radiological dose and excess cancer risk to an individual who is exposed while located within or outside the area of initial (primary) contamination. The HYDROGEOCHEM is a 3-D numerical model of fluid flow, thermal, hydrologic transport, and biogeochemical kinetic and equilibrium reactions in saturated and unsaturated media. The HYDROGEOCHEM model can also simulate the crucial geochemical mechanism, such as the effect of redox processes on the adsorption/desorption, hydrogeochemical influences on concrete degradation, adsorption/desorption of radionuclides (i.e., surface complexation model) between solid and liquid phase in geochemically dynamic environments. To investigate the safety assessment of LLW disposal facility, linking RESRAD-OFFSITE and HYDROGEOCHEM model can provide detailed tools of confidence in the protectiveness of the human health and environmental impact for safety assessment of LLW disposal facility. (authors)
Modeling Temporal Behavior in Large Networks: A Dynamic Mixed-Membership Model
Rossi, R; Gallagher, B; Neville, J; Henderson, K
2011-11-11T23:59:59.000Z
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.
Chen, Yong
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
Dissipative particle dynamics model for colloid transport in porous media
Pan, Wenxiao; Tartakovsky, Alexandre M.
2013-08-01T23:59:59.000Z
We present that the transport of colloidal particles in porous media can be effectively modeled with a new formulation of dissipative particle dynamics, which augments standard DPD with non-central dissipative shear forces between particles while preserving angular momentum. Our previous studies have demonstrated that the new formulation is able to capture accurately the drag forces as well as the drag torques on colloidal particles that result from the hydrodynamic retardation e?ect. In the present work, we use the new formulation to study the contact e?ciency in colloid ?ltration in saturated porous media. Note that the present model include all transport mechanisms simultaneously, including gravitational sedimentation, interception and Brownian di?usion. Our results of contact e?ciency show a good agreement with the predictions of the correlation equation proposed by Tufenkji and EliMelech, which also incorporate all transport mechanisms simultaneously without the additivity assumption.
Dynamic chirality in the interacting boson fermion-fermion model
Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Tonev, D. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Institute for Nuclear Research and Nuclear Energy, BAS, 1784 Sofia (Bulgaria); De Angelis, G. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Ventura, A. [Ente per le Nuove tecnologie, l'Energia e l'Ambiente, I-40129 Bologna and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy)
2008-09-15T23:59:59.000Z
The chiral interpretation of twin bands in odd-odd nuclei was investigated in the interacting boson fermion-fermion model. The analysis of the wave functions has shown that the possibility for angular momenta of the valence proton, neutron and core to find themselves in the favorable, almost orthogonal geometry is present, but not dominant. Such behavior is found to be similar in nuclei where both the level energies and the electromagnetic decay properties display the chiral pattern, as well as in those where only the level energies of the corresponding levels in the twin bands are close together. The difference in the structure of the two types of chiral candidates nuclei can be attributed to different {beta} and {gamma} fluctuations, induced by the exchange boson-fermion interaction of the interacting boson fermion-fermion model. In both cases the chirality is weak and dynamic.
Ünver, Hakk? Özgür
2008-01-01T23:59:59.000Z
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 ...
Model Studies of the Dynamics of Bacterial Flagellar Motors
Bai, F; Lo, C; Berry, R; Xing, J
2009-03-19T23:59:59.000Z
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.
The Dynamically Extended Mind -- A Minimal Modeling Case Study
Tom Froese; Carlos Gershenson; David A. Rosenblueth
2013-05-08T23:59:59.000Z
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.
Automated Software Engineering Process Assessment: Supporting Diverse Models using an Ontology
Ulm, Universität
, ISO 9001). It also provides an in-the-loop automated process assessment capability that can help, ISO 9001), and suitable performance and scalability. The approach can reduce the effort required assessment while simultaneously supporting diverse process assessment reference models (CMMI, ISO/IEC 15504
Modelling of Stochastic Hybrid Systems with Applications to Accident Risk Assessment
Del Moral , Pierre
Modelling of Stochastic Hybrid Systems with Applications to Accident Risk Assessment #12;The SYSTEMS WITH APPLICATIONS TO ACCIDENT RISK ASSESSMENT DISSERTATION to obtain the doctor's degree promotor Prof. dr. A. Bagchi #12;Contents 1 Introduction 3 1.1 Accident risk assessment
Modeling the Dynamic Behavior of a Single Pile in Dry Sand using a new p-y Material Model
Choi, JungIn; Brandenberg, Scott J; Kim, MyoungMo
2013-01-01T23:59:59.000Z
of dynamic pile behavior by centrifuge tests consideringof KOCED geotechnical centrifuge and its shear wave velocitysurface plasticity theory. Centrifuge model data analyzed
Kunsman, David Marvin; Aldemir, Tunc (Ohio State University); Rutt, Benjamin (Ohio State University); Metzroth, Kyle (Ohio State University); Catalyurek, Umit (Ohio State University); Denning, Richard (Ohio State University); Hakobyan, Aram (Ohio State University); Dunagan, Sean C.
2008-05-01T23:59:59.000Z
This LDRD project has produced a tool that makes probabilistic risk assessments (PRAs) of nuclear reactors - analyses which are very resource intensive - more efficient. PRAs of nuclear reactors are being increasingly relied on by the United States Nuclear Regulatory Commission (U.S.N.R.C.) for licensing decisions for current and advanced reactors. Yet, PRAs are produced much as they were 20 years ago. The work here applied a modern systems analysis technique to the accident progression analysis portion of the PRA; the technique was a system-independent multi-task computer driver routine. Initially, the objective of the work was to fuse the accident progression event tree (APET) portion of a PRA to the dynamic system doctor (DSD) created by Ohio State University. Instead, during the initial efforts, it was found that the DSD could be linked directly to a detailed accident progression phenomenological simulation code - the type on which APET construction and analysis relies, albeit indirectly - and thereby directly create and analyze the APET. The expanded DSD computational architecture and infrastructure that was created during this effort is called ADAPT (Analysis of Dynamic Accident Progression Trees). ADAPT is a system software infrastructure that supports execution and analysis of multiple dynamic event-tree simulations on distributed environments. A simulator abstraction layer was developed, and a generic driver was implemented for executing simulators on a distributed environment. As a demonstration of the use of the methodological tool, ADAPT was applied to quantify the likelihood of competing accident progression pathways occurring for a particular accident scenario in a particular reactor type using MELCOR, an integrated severe accident analysis code developed at Sandia. (ADAPT was intentionally created with flexibility, however, and is not limited to interacting with only one code. With minor coding changes to input files, ADAPT can be linked to other such codes.) The results of this demonstration indicate that the approach can significantly reduce the resources required for Level 2 PRAs. From the phenomenological viewpoint, ADAPT can also treat the associated epistemic and aleatory uncertainties. This methodology can also be used for analyses of other complex systems. Any complex system can be analyzed using ADAPT if the workings of that system can be displayed as an event tree, there is a computer code that simulates how those events could progress, and that simulator code has switches to turn on and off system events, phenomena, etc. Using and applying ADAPT to particular problems is not human independent. While the human resources for the creation and analysis of the accident progression are significantly decreased, knowledgeable analysts are still necessary for a given project to apply ADAPT successfully. This research and development effort has met its original goals and then exceeded them.
Toward a mechanistic modeling of nitrogen limitation on vegetation dynamics
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
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.
MODEST: modeling stellar evolution and (hydro)dynamics
Piet Hut
2003-09-15T23:59:59.000Z
Simulations of dense stellar systems currently face two major hurdles, one astrophysical and one computational. The astrophysical problem lies in the fact that several major stages in binary evolution, such as common envelope evolution, are still poorly understood. The best we can do in these cases is to parametrize our ignorance, in a way that is reminiscent of the introduction of a mixing length to describe convection in a single star, or an alpha parameter in modeling an accretion disk. The hope is that by modeling a whole star cluster in great detail, and comparing the results to the wealth of observational data currently available, we will be able to constrain the parameters that capture the unknown physics. The computational problem is one of composition: while we have accurate computer codes for modeling stellar dynamics, stellar hydrodynamics, and stellar evolution, we currently have no good way to put all this knowledge together in a single software environment. A year ago, a loosely-knit organization was founded to address these problems, MODEST for MOdeling DEnse STellar systems, with nine working groups and a series of meetings that are held every half year. This report reviews the first year of this initiative. Much more detail can be found on the MODEST web site http://www.manybody.org/modest.html .
assessment modeling approach: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
an easyEnvironmental impact for offshore wind farms: Geolocalized Life Cycle Assessment (LCA) approach and floating offshore wind farms. This work was undertaken within the EU-...
A Statistical Model to Assess Indirect CO2 Emissions of the UAE Residential Sector
Radhi, H.; Fikry, F.
2010-01-01T23:59:59.000Z
This study presents a regional bottom-up model for assessing space cooling energy and related greenhouse gas emissions. The model was developed with the aim of improving the quality and quantity of cooling energy and emission data, especially...
Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems
Ha, Soonhoi
Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems Hae-woo Park Kyoungjoo Oh of synchronous data-flow (SDF) Âmodeled 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
Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances
Tsiotras, Panagiotis
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
Object-oriented Dynamics Modeling for Legged Robot Trajectory Optimization and Control
Stryk, Oskar von
Object-oriented Dynamics Modeling for Legged Robot Trajectory Optimization and Control Robert. To facilitate the investigation of new concepts of nonlinear model-based optimization and control methods also-level specification of multibody dynamics models using component libraries serves as a basis for generation
Technical Note Comparing Dynamic Causal Models using AIC, BIC and Free Energy
Penny, Will
Technical Note Comparing Dynamic Causal Models using AIC, BIC and Free Energy W.D. Penny Wellcome) and Dynamic Causal Models (DCMs). We find that the Free Energy has the best model selection ability, to instead score DCMs using the Free Energy (Friston et al., 2007a). However, until now there has been
Capacitive effect of cavitation in xylem conduits: results from a dynamic model
Mencuccini, Maurizio
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
Paris-Sud XI, Université de
1 Assessing nitrogen losses after sewage sludge spreading: A method based on simulation models performances. We define 45 sewage sludge spreading scenarios covering a wide range of situations in France. Several models are used to (i) assess nitrogen losses due to sewage sludge spreading and (ii) calculate
11/05/2007 16:29 1 Bayesian Belief Network Model for the Safety Assessment
Fenton, Norman
11/05/2007 16:29 1 Bayesian Belief Network Model for the Safety Assessment of Nuclear Computer assessment task for computer and software based nuclear systems important to safety. Our model is developed University P.-J. Courtois AV Nuclear Brussels, Belgium Abstract The formalism of Bayesian Belief Networks
Assessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling
Fisher, Andrew
with a regional groundwater model to assess the hydrologic impact of potential MAR placement and operating planning, including evaluation of options for enhancing groundwater resources. Introduction ManagedAssessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling by Tess A. Russo1
Como, Giacomo
Automating efficiency-targeted approximations in modelling and simulation tools: dynamic decoupling (classical) efficiency-targeted approximation tech- niques, within a unified framework. Some application
Emerging disease dynamics in a model coupling within-host and ...
Xiuli Cen
2014-08-27T23:59:59.000Z
Aug 2, 2014 ... Immunological models consider the within-host dynamics independent of the interactions between hosts (e.g., De Leenheer and Smith, 2003;.
A model for coupling within-host and between-host dynamics in an ...
2011-12-20T23:59:59.000Z
Abstract Studies on the modeling of the coupled dy- namics of infectious diseases at both the population level (the epidemic process or between-host dynamics).
Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle are derived either at microscale with random distribution of material properties or at a mesoscale
EPR pairing dynamics in Hubbard model with resonant $U$
X. Z. Zhang; Z. Song
2015-04-28T23:59:59.000Z
We study the dynamics of the collision between two fermions in Hubbard model with on-site interaction strength $U$. The exact solution shows that the scattering matrix for two-wavepacket collision is separable into two independent parts, operating on spatial and spin degrees of freedom, respectively. The S-matrix for spin configuration is equivalent to that of Heisenberg-type pulsed interaction with the strength depending on $U$ and relative group velocity $\\upsilon _{r}$. This can be applied to create distant EPR pair, through a collision process for two fermions with opposite spins in the case of $\\left\\vert \\upsilon _{r}/U\\right\\vert =1$,\\ without the need for temporal control and measurement process. Multiple collision process for many particles is also discussed.
Hydro-dynamical models for the chaotic dripping faucet
P. Coullet; L. Mahadevan; C. S. Riera
2004-08-20T23:59:59.000Z
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.
Some optical and dynamical phenomena in the Rindler model
E. Birsin; W. Hasse
2014-11-15T23:59:59.000Z
In Rindler's model of a uniformly accelerated reference frame we analyze the apparent shape of rods and marked light rays for the case that the observers as well as the rods and the sources of light are at rest with respect to the Rindler observers. Contrary to the expectation suggested by the strong principle of equivalence, there is no apparent "bending down" of a light ray with direction transversal to the direction of acceleration, but a straight rod oriented orthogonal to the direction of acceleration appears bended "upwards". These optical phenomena are in accordance with the dynamical experience of observers guided by a straight track or a track curved in the same way as the marked light ray, respectively: While the former observer feels a centrifugal force directed "downwards", the centrifugal force for the latter vanishes. The properties of gyroscope transport along such tracks are correspondingly.
Dynamic Markov bridges motivated by models of insider trading
Campi, Luciano; Danilova, Albina
2012-01-01T23:59:59.000Z
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.
Tyre modelling for use in vehicle dynamics studies
Bakker, E.; Nyborg, L.; Pacejka, H.B.
1987-01-01T23:59:59.000Z
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.
Dynamical modeling of the Deep Impact dust ejecta cloud
Tanyu Bonev; Nancy Ageorges; Stefano Bagnulo; Luis Barrera; Hermann B{ö}hnhardt; Olivier Hainaut; Emmanuel Jehin; Hans-Ullrich K{ä}ufl; Florian Kerber; Gaspare LoCurto; Jean Manfroid; Olivier Marco; Eric Pantin; Emanuela Pompei; Ivo Saviane; Fernando Selman; Chris Sterken; Heike Rauer; Gian Paolo Tozzi; Michael Weiler
2007-03-21T23:59:59.000Z
The collision of Deep Impact with comet 9P/Tempel 1 generated a bright cloud of dust which dissipated during several days after the impact. The brightness variations of this cloud and the changes of its position and shape are governed by the physical properties of the dust grains. We use a Monte Carlo model to describe the evolution of the post-impact dust plume. The results of our dynamical simulations are compared to the data obtained with FORS2, the FOcal Reducer and low dispersion Spectrograph for the VLT of the European Southern Observatory (ESO), to derive the particle size distribution and the total amount of material contained in the dust ejecta cloud.
Shear band dynamics from a mesoscopic modeling of plasticity
E. A. Jagla
2010-06-07T23:59:59.000Z
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.
Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.
Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan
2011-06-01T23:59:59.000Z
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.
Idealized test cases for the dynamical cores of Atmospheric General Circulation Models
Jablonowski, Christiane
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
Physica D 159 (2001) 3557 Wave group dynamics in weakly nonlinear long-wave models
Pelinovsky, Dmitry
Physica D 159 (2001) 35Â57 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; KortewegÂde Vries equation; Nonlinear SchrÂ¨odinger equation 1
Shell Model Dynamics of HCl on the MgO(001) Surface Terrace Andreas Markmann,1
Markmann, Andreas
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
Application of Extended Kalman Filter Techniques for Dynamic Model Parameter Calibration
Huang, Zhenyu; Du, Pengwei; Kosterev, Dmitry; Yang, Bo
2009-07-26T23:59:59.000Z
Abstract -Phasor measurement has previously been used for sub-system model validation, which enables rigorous comparison of model simulation and recorded dynamics and facilitates identification of problematic model components. Recent work extends the sub-system model validation approach with a focus on how model parameters may be calibrated to match recorded dynamics. In this paper, a calibration method using Extended Kalman Filter (EKF) technique is proposed. This paper presents the formulation as well as case studies to show the validity of the EKF-based parameter calibration method. The proposed calibration method is expected to be a cost-effective means complementary to traditional equipment testing for improving dynamic model quality.
Computation Modeling and Assessment of Nanocoatings for Ultra Supercritical Boilers
J. Shingledecker; D. Gandy; N. Cheruvu; R. Wei; K. Chan
2011-06-21T23:59:59.000Z
Forced outages and boiler unavailability of coal-fired fossil plants is most often caused by fire-side corrosion of boiler waterwalls and tubing. Reliable coatings are required for Ultrasupercritical (USC) application to mitigate corrosion since these boilers will operate at a much higher temperatures and pressures than in supercritical (565 C {at} 24 MPa) boilers. Computational modeling efforts have been undertaken to design and assess potential Fe-Cr-Ni-Al systems to produce stable nanocrystalline coatings that form a protective, continuous scale of either Al{sub 2}O{sub 3} or Cr{sub 2}O{sub 3}. The computational modeling results identified a new series of Fe-25Cr-40Ni with or without 10 wt.% Al nanocrystalline coatings that maintain long-term stability by forming a diffusion barrier layer at the coating/substrate interface. The computational modeling predictions of microstructure, formation of continuous Al{sub 2}O{sub 3} scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. Advanced coatings, such as MCrAl (where M is Fe, Ni, or Co) nanocrystalline coatings, have been processed using different magnetron sputtering deposition techniques. Several coating trials were performed and among the processing methods evaluated, the DC pulsed magnetron sputtering technique produced the best quality coating with a minimum number of shallow defects and the results of multiple deposition trials showed that the process is repeatable. scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. The cyclic oxidation test results revealed that the nanocrystalline coatings offer better oxidation resistance, in terms of weight loss, localized oxidation, and formation of mixed oxides in the Al{sub 2}O{sub 3} scale, than widely used MCrAlY coatings. However, the ultra-fine grain structure in these coatings, consistent with the computational model predictions, resulted in accelerated Al diffusion from the coating into the substrate. An effective diffusion barrier interlayer coating was developed to prevent inward Al diffusion. The fire-side corrosion test results showed that the nanocrystalline coatings with a minimum number of defects have a great potential in providing corrosion protection. The coating tested in the most aggressive environment showed no evidence of coating spallation and/or corrosion attack after 1050 hours exposure. In contrast, evidence of coating spallation in isolated areas and corrosion attack of the base metal in the spalled areas were observed after 500 hours. These contrasting results after 500 and 1050 hours exposure suggest that the premature coating spallation in isolated areas may be related to the variation of defects in the coating between the samples. It is suspected that the cauliflower-type defects in the coating were presumably responsible for coating spallation in isolated areas. Thus, a defect free good quality coating is the key for the long-term durability of nanocrystalline coatings in corrosive environments. Thus, additional process optimization work is required to produce defect-free coatings prior to development of a coating application method for production parts.
Georgia, University of
Models, Modeling Dynamic Systems, DOI 10.1007/978-1-4614-1257-1_7, Â© 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
[10-386] Assessing and Improving the Scale Dependence of Ecosystem Processes in Earth System Models
. Goodale Cornell U. *Overall Project Lead *Lead Institution Intellectual Merit: Earth system models include policies. Our research assesses and improves Earth system model simulations of the carbon cycle, ecosystem of the Community Climate System Model/Community Earth System Model, which includes statistical meteorological
Modeling toxic endpoints for improving human health risk assessment
Bruce, Erica Dawn
2009-05-15T23:59:59.000Z
Risk assessment procedures for mixtures of polycyclic aromatic hydrocarbons (PAHs) present a problem due to the lack of available potency and toxicity data on mixtures and individual compounds. This study examines the toxicity of parent compound...
Model for a web based medical technology assessment system
Prabhu, Gopal
1999-01-01T23:59:59.000Z
. 6. Figure 3. 7. Figure 3. 8. Figure 3. 9. Telemetry Assessment 37 ECG Assessment. 39 The Home Page 43 Clinical Engineer Registration. Clinical Engineer Login. . 44 45 Search Results When User Searches for Defibrillator by ID. . 41 Figure... to those, which your facility is considering, or the information may be dated (pers. comm. N. Cram). The Internet is a computer network that connects millions of computers globally and provides worldwide communications to businesses, homes, schools...
Adaptive Optimal Feedback Control with Learned Internal Dynamics Models
Mitrovic, Djordje; Klanke, Stefan; Vijayakumar, Sethu
2010-01-01T23:59:59.000Z
, have focused on the case of non-linear, but still analytically available, dynamics. For realistic control systems, however, the dynamics may often be unknown, difficult to estimate, or subject to frequent systematic changes. In this chapter, we combine...
Assessing Models of Public Understanding In ELSI Outreach Materials
Bruce V. Lewenstein, Ph.D.; Dominique Brossard, Ph.D.
2006-03-01T23:59:59.000Z
Advances in the science of genetics have implications for individuals and society, and have to be taken into account at the policy level. Studies of ethical, legal and social issues related to genomic research have therefore been integrated in the Human Genome Project (HGP) since the earliest days of the project. Since 1990, three to five percent of the HGP annual budget has been devoted to such studies, under the umbrella of the Ethical, Legal, and Social Implications (ELSI) Programs of the National Human Genome Research Institute of the National Institute of Health, and of the Office of Biological and Environmental Research of the U.S. Department of Energy (DOE). The DOE-ELSI budget has been used to fund a variety of projects that have aimed at ?promoting education and help guide the conduct of genetic research and the development of related medical and public policies? (HGP, 2003). As part of the educational component, a significant portion of DOE-ELSI funds have been dedicated to public outreach projects, with the underlying goal of promoting public awareness and ultimately public discussion of ethical, legal, and social issues surrounding availability of genetic information (Drell, 2002). The essential assumption behind these projects is that greater access to information will lead to more knowledge about ethical, legal and social issues, which in turn will lead to enhanced ability on the part of individuals and communities to deal with these issues when they encounter them. Over the same period of time, new concepts of ?public understanding of science? have emerged in the theoretical realm, moving from a ?deficit? or linear dissemination of popularization, to models stressing lay-knowledge, public engagement and public participation in science policy-making (Lewenstein, 2003). The present project uses the base of DOE-funded ELSI educational project to explore the ways that information about a new and emerging area of science that is intertwined with public issues has been used in educational public settings to affect public understanding of science. After a theoretical background discussion, our approach is three-fold. First, we will provide an overview, a ?map? of DOE-funded of outreach programs within the overall ELSI context to identify the importance of the educational component, and to present the criteria we used to select relevant and representative case studies. Second, we will document the history of the case studies. Finally, we will explore an intertwined set of research questions: (1) To identify what we can expect such projects to accomplish -in other words to determine the goals that can reasonably be achieved by different types of outreach, (2) To point out how the case study approach could be useful for DOE-ELSI outreach as a whole, and (3) To use the case study approach as a basis to test theoretical models of science outreach in order to assess to what extent those models accord with real world outreach activities. For this last goal, we aim at identifying what practices among ELSI outreach activities contribute most to dissemination, or to participation, in other words in which cases outreach materials spark action in terms of public participation in decisions about scientific issues.
A spatially structured metapopulation model with patch dynamics
2007-08-22T23:59:59.000Z
Sep 30, 2005 ... creation) and metapopulation dynamics (patch colonization and extinction). ... genetic structure (Gaines and Lyons, 1997), and commu-.
Stochastic model for aerodynamic force dynamics on wind turbine blades in unsteady wind inflow
Luhur, Muhammad Ramzan; Kühn, Martin; Wächter, Matthias
2015-01-01T23:59:59.000Z
The paper presents a stochastic approach to estimate the aerodynamic forces with local dynamics on wind turbine blades in unsteady wind inflow. This is done by integrating a stochastic model of lift and drag dynamics for an airfoil into the aerodynamic simulation software AeroDyn. The model is added as an alternative to the static table lookup approach in blade element momentum (BEM) wake model used by AeroDyn. The stochastic forces are obtained for a rotor blade element using full field turbulence simulated wind data input and compared with the classical BEM and dynamic stall models for identical conditions. The comparison shows that the stochastic model generates additional extended dynamic response in terms of local force fluctuations. Further, the comparison of statistics between the classical BEM, dynamic stall and stochastic models' results in terms of their increment probability density functions gives consistent results.
Ultrafast Structural Dynamics in Combustion Relevant Model Systems
Weber, Peter M. [Brown University
2014-03-31T23:59:59.000Z
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
Networking technology adoption : system dynamics modeling of fiber-to-the-home
Kelic, Andjelka, 1972-
2005-01-01T23:59:59.000Z
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 ...
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...
Optimal foreign borrowing in a multisector dynamic equilibrium model for Brazil
Tourinho, Octv?io A. F.
1985-01-01T23:59:59.000Z
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 ...
DYNAMIC MODELING AND CONTROL OF REACTIVE DISTILLATION FOR HYDROGENATION OF BENZENE
Aluko, Obanifemi
2010-01-16T23:59:59.000Z
This work presents a modeling and control study of a reactive distillation column used for hydrogenation of benzene. A steady state and a dynamic model have been developed to investigate control structures for the column. The most important aspects...
Multiple Model Robust Dynamic Programming Eric C. Whitman and Christopher G. Atkeson
-- Modeling error is a common problem for model- based control techniques. We present multiple model dynamic programming (MMDP) as a method to generate controllers that are robust to modeling error. Our method generates controllers that are approximately optimal for a collection of models, thereby forcing the controller
Protecting the African elephant: A dynamic bioeconomic model of ivory trade
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 Mathematical programming Trade quota A B S T R A C T A dynamic bioeconomic model of ivory trade is used
STOCHASTIC COMPUTATIONAL DYNAMICAL MODEL OF UNCERTAIN STRUCTURE COUPLED WITH AN INSULATION LAYER
Boyer, Edmond
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
A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller
Paris-Sud XI, UniversitÃ© de
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
Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results
Tsiotras, Panagiotis
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
Bierlaire, Michel
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 FlÂ¨otterÂ¨od Michel Bierlaire Abstract We derive a dynamic network
ROLE OF VEHICLE DYNAMIC MODELING FIDELITY WITH HAPTIC COLLABORATION IN STEER BY WIRE
Krovi, Venkat
ROLE OF VEHICLE DYNAMIC MODELING FIDELITY WITH HAPTIC COLLABORATION IN STEER BY WIRE SYSTEMS control back to the driver. Candidate solutions for mimicking the steering feel have ranged from direct torque prediction schemes based on mathematical dynamics models (of tire-road, suspension, power-steering
NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING
Stewart, Sarah T.
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
Gupta, Rajesh
A Model Checking Approach to Evaluating System Level Dynamic Power Management Policies for Embedded, and laptops, controlling power dissipation is an important system design issue [2]. This is either because enforced at the system level. In [3], a system modeling ap- proach for dynamic power management strategy
AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT
Avignon et des Pays de Vaucluse, Université de
AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT A. El Ayadi 1 , B. Picoux 1 , G to study a Falling Weight Deectometer test conducted on a exible pavement. These dynamic models take with in situ measurements recorded on an instrumented pavement; such a comparison has indicated the importance
Dynamic Versus Steady-State Modeling of FACTS Controllers in Transmission Congestion
CaÃ±izares, Claudio A.
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
A Dynamic Model for Phase Transformations in 3D Samples of Shape Memory Alloys
Melnik, Roderick
A Dynamic Model for Phase Transformations in 3D Samples of Shape Memory Alloys D.R. Mahapatra and R Introduction Modelling of dynamics of phase transformations (PT) in Shape Memory Al- loys (SMAs) under which assist the researchers in designing new materials and devices by harnessing the shape memory
Nagurney, Anna
An Efficiency Measure for Dynamic Networks Modeled as Evolutionary Variational Inequalities propose an efficiency/performance measure for dynamic net- works, which have been modeled as evolutionary and their rankings. We provide both continuous time and discrete time versions of the efficiency measure. We
A model for dynamic chance constraints in hydro power reservoir management
Römisch, Werner
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
Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed)
Sadoulet, Elisabeth
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
A Groundwater Dynamic Simulation Model: Application to the Upper San Pedro Basin
Fay, Noah
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 Initiative Fund, Water Sustainability Graduate Fellowship Program 2004/2005 #12;2 Introduction Located
Coupled thermodynamic-dynamic semi-analytical model of Free Piston Stirling engines
Formosa, Fabien
2013-01-01T23:59:59.000Z
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...
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
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.
Janetos, Anthony C.; Collins, William D.; Wuebbles, D.J.; Diffenbaugh, Noah; Hayhoe, Katharine; Hibbard, Kathleen A.; Hurtt, George
2012-03-31T23:59:59.000Z
This is the full workshop report for the modeling workshop we did for the National Climate Assessment, with DOE support.
Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,*
Chen, Qingyan "Yan"
1 Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,* , Kisup Leeb ventilation systems for buildings requires a suitable tool to assess the system performance-scale experimental, multizone network, zonal, and CFD) for predicting ventilation performance in buildings, which can
U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS, AND NGL
Laughlin, Robert B.
AM-i Chapter AM U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS Survey (USGS) periodically conducts assessments of the oil, gas, and natural-gas liquids (NGL) resources by the USGS in1998 for undiscovered oil, gas, and NGL resources that reside in conventional accumulations
A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery
A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery; published 30 January 2004. [1] Solar radiation assessment by satellite is constrained by physical Composition and Structure: Transmission and scattering of radiation; KEYWORDS: solar radiation, satellite
Paris-Sud XI, UniversitÃ© de
1 Assessing residential exposure to urban noise using environmental models: does the size on the quantification of the exposure level in a surface defined as the subject's exposure area. For residential residential buildings. Twelve noise exposure indicators have been used to assess inhabitants' exposure
Integrated dynamic landscape analysis and modeling system (IDLAMS) : installation manual.
Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.
1999-02-24T23:59:59.000Z
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.
Integrated dynamic landscape analysis and modeling system (IDLAMS) : programmer's manual.
Klaus, C. M.; Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.
1999-02-24T23:59:59.000Z
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.
The modeling of aerosol dynamics during degraded core events
Clausse, A.; Lahey, R.T. Jr.
1989-01-01T23:59:59.000Z
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.
Multi-model assessment of stratospheric ozone return dates and ozone recovery in
Wirosoetisno, Djoko
Multi- model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models of stratospheric ozone return dates and ozone recovery in CCMVal-2 models V. Eyring1, I. Cionni1, G. E. Bodeker2, A September 2010 Published: 7 October 2010 Abstract. Projections of stratospheric ozone from a suite
Towing tank PIV measurement system, data and uncertainty assessment for DTMB Model 5512
Gui, Lichuan
Basin (DTMB) model 5512. The mean velocities are compared with previous 5-hole pitot probe dataTowing tank PIV measurement system, data and uncertainty assessment for DTMB Model 5512 L. Gui, J stresses at the nominal-wake plane of a model-scale ship. The mean velocities are compared with previous 5
Assessing ocean-model sensitivity to wind forcing uncertainties I. Andreu Burillo,1
Assessing ocean-model sensitivity to wind forcing uncertainties I. Andreu Burillo,1 G. Caniaux,1 M-equation open-ocean model, induced by uncertainties in wind forcing. Statistics calculated from an ensemble-model sensitivity to wind forcing uncertainties, Geophys. Res. Lett., 29(18), 1858, doi:10.1029/2001GL014473, 2002
Conceptual design of an integrated technology model for carbon policy assessment.
Backus, George A.; Dimotakes, Paul E. (NASA Jet Propulsion Laboratory, Pasadena, CA)
2011-01-01T23:59:59.000Z
This report describes the conceptual design of a technology choice model for understanding strategies to reduce carbon intensity in the electricity sector. The report considers the major modeling issues affecting technology policy assessment and defines an implementable model construct. Further, the report delineates the basis causal structure of such a model and attempts to establish the technical/algorithmic viability of pursuing model development along with the associated analyses.
Fire dynamics during the 20th century simulated by the Community Land Model
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
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 ...
Models used to assess the performance of photovoltaic systems.
Stein, Joshua S.; Klise, Geoffrey T.
2009-12-01T23:59:59.000Z
This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.
Sandia National Laboratories: model of solar purchase dynamics
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of solar purchase dynamics Price Premiums for Solar Home Sales On February 25, 2015, in Energy, News, News & Events, Partnership, Photovoltaic, Renewable Energy, Solar, Systems...
Dynamics of an age-structured metapopulation model
2005-10-28T23:59:59.000Z
address the temporal dynamics that characterize local popu- lations in ... this metapopulation framework, two structures have emerged as being critical in the ...
Assessing Uncertainty in Spatial Exposure Models for Air Pollution Health Effects Assessment
2007-01-01T23:59:59.000Z
Spatial analysis of air pollution and mor- tality in Loslinking chronic air pollution exposure to health outcomes. J2006. Bayesian modeling of air pollution health effects with
Cirpka, Olaf Arie
1 Integrated modelling and assessment of regional groundwater resources in Germany and Benin, West.J.S. SONNEVELD [1] Institute of Hydraulic Engineering, Universitaet Stuttgart, Germany (Roland Conservation University of Bonn, Germany [3] Institute of Landscape Planning and Ecology, University
BIOMECHANICAL ANALYSIS OF TWO SIMPLE DYNAMICAL MODELS FOR THE HUMAN GAIT
Llanos, Diego R.
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
Rate models with delays and the dynamics of large networks of spiking neurons
Roxin, Alex
1 Rate models with delays and the dynamics of large networks of spiking neurons Alex Roxin, Nicolas in a reduced rate model provided that the interactions are delayed. §1. Introduction Simplified models of large transformation through a sigmoidal input-output transfer function. Network models of spiking neurons can
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
A Business Model Framework for Dynamic Spectrum Access in Cognitive Networks
Ha, Dong S.
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
Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment
Cowan-Ellsberry, Christina E.
2010-01-01T23:59:59.000Z
chlorinated pesticides, e.g. , DDT) based on Swedish marketInvestigating the global fate of DDT: Model evaluation anddichlorodiphenyltrichloroethane (DDT), and its degradation
A new analytic-adaptive model for EGS assessment, development...
Investigator(s) George Danko, UNR Other Principal Investigators Jens Birkholzer, LBNL; Jaak Daemen, UNR Targets Milestones The model development work follows three main...
assessment models version: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Szilagyi a is modeled with a spatially and temporally discretized version of the linear kinematic wave equation written-aquifer interactions; Baseflow separation; Flow routing;...
assessment model version: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Szilagyi a is modeled with a spatially and temporally discretized version of the linear kinematic wave equation written-aquifer interactions; Baseflow separation; Flow routing;...
Utility of Social Modeling in Assessment of a State’s Propensity for Nuclear Proliferation
Coles, Garill A.; Brothers, Alan J.; Whitney, Paul D.; Dalton, Angela C.; Olson, Jarrod; White, Amanda M.; Cooley, Scott K.; Youchak, Paul M.; Stafford, Samuel V.
2011-06-01T23:59:59.000Z
This report is the third and final report out of a set of three reports documenting research for the U.S. Department of Energy (DOE) National Security Administration (NASA) Office of Nonproliferation Research and Development NA-22 Simulations, Algorithms, and Modeling program that investigates how social modeling can be used to improve proliferation assessment for informing nuclear security, policy, safeguards, design of nuclear systems and research decisions. Social modeling has not to have been used to any significant extent in a proliferation studies. This report focuses on the utility of social modeling as applied to the assessment of a State's propensity to develop a nuclear weapons program.
JACKSON VL
2011-08-31T23:59:59.000Z
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.
Hays, Kelley Ann
1999-01-01T23:59:59.000Z
in thickets suggest some thickets may be recent at Kenedy. []¹?N of plants and soils did not enhance interpretation of vegetation dynamics at either site, but may provide insights regarding the N-cycle of these oak communities....
Markakis, Michail
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 ...
Model Fire Protection Assessment Guide | 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 DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311,OfficialProducts | Department of EnergyMobileAssessment
Comparing partial-wave amplitude parametrization with dynamical models of meson-nucleon scattering
Mark W. Paris; Ron L. Workman
2011-02-28T23:59:59.000Z
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.
Aquifer sensitivity assessment modeling at a large scale
Berg, R.C.; Abert, C.C. (Illinois State Geological Survey, Champaign, IL (United States))
1994-03-01T23:59:59.000Z
A 480 square-mile region within Will County, northeastern Illinois was used as a test region for an evaluation of the sensitivity of aquifers to contamination. An aquifer sensitivity model was developed using a Geographic Information System (GIS) with ARC/INFO software to overlay and combine several data layers. Many of the input data layers were developed using 2-dimensional surface modeling (Interactive Surface Modeling (ISM)) and 3-dimensional volume modeling (Geologic Modeling Program (GMP)) computer software. Most of the input data layers (drift thickness, thickness of sand and gravel, depth to first aquifer) were derived from interpolation of descriptive logs for water wells and engineering borings from their study area. A total of 2,984 logs were used to produce these maps. The components used for the authors' model are (1) depth to sand and gravel or bedrock, (2) thickness of the uppermost sand and gravel aquifer, (3) drift thickness, and (4) absence or presence of uppermost bedrock aquifer. The model is an improvement over many aquifer sensitivity models because it combines specific information on depth to the uppermost sand and gravel aquifer with information on the thickness of the uppermost sand and gravel aquifer. The manipulation of the source maps according to rules-based assumptions results in a colored aquifer sensitivity map for the Will County study area. This colored map differentiates 42 aquifer sensitivity map areas by using line patterns within colors. The county-scale model results in an aquifer sensitivity map that can be a useful tool for making land-use planning decisions regarding aquifer protection and management of groundwater resources.
Wahl, L.E.
1994-03-01T23:59:59.000Z
Radiological risk assessments and resulting risk estimates have been developed by numerous national and international organizations, including the National Research Council`s fifth Committee on the Biological Effects of Ionizing Radiations (BEIR V), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the International Commission on Radiological Protection (ICRP). A fourth organization, the Environmental Protection Agency (EPA), has also performed a risk assessment as a basis for the National Emission Standards for Hazardous Air Pollutants (NESHAP). This paper compares the EPA`s model of risk assessment with the models used by the BEIR V Committee, UNSCEAR, and ICRP. Comparison is made of the values chosen by each organization for several model parameters: populations used in studies and population transfer coefficients, dose-response curves and dose-rate effects, risk projection methods, and risk estimates. This comparison suggests that the EPA has based its risk assessment on outdated information and that the organization should consider adopting the method used by the BEIR V Committee, UNSCEAR, or ICRP.
Isomorphic classical molecular dynamics model for an excess electronin a supercritical fluid
Miller III, Thomas F.
2008-08-04T23:59:59.000Z
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}.
assessing local model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Ying; Peng Xinguang 243 Web tool for energy policy decision-making through geo-localized LCA models: A focus on offshore wind farms in Northern Europe Physics Websites Summary: 1...
Model Assessment with Renormalization Group in Statistical Learning
GingQuo, Wang
2013-01-01T23:59:59.000Z
Clustering: 50 years beyond K-means,” Pattern Recognitionas Fig. 2a). Perform the k-means clustering algorithm, whichThe coarse set and model. The k-means clustering algorithm—
Assessment of reduced mechanisms using One Dimensional Stochastic Turbulence model
Chien, Li-Chun
2010-01-01T23:59:59.000Z
turbulence model for a syngas jet flame. Proceeding of FallKerstein 2002), a turbulent syngas (CO/H2/NO) jet flame wasand DNS results of the syngas jet flame was recently done
Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL
2006-07-01T23:59:59.000Z
Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be used to assess whether a prescribed mitigation is likely to meet intended objectives from both a water quality and a biological resource perspective. These techniques can be used to assess the tradeoffs between hydropower operations, power generation, and environmental quality.
Chi, K C; Reiner, David; Nuttall, William J
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...
Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu; Basu, Nandita; Li, Hongyi; Wang, Shaowen
2012-06-30T23:59:59.000Z
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.
Dynamic reduced order modeling of entrained flow gasifiers
Monaghan, Rory F. D. (Rory Francis Desmond)
2010-01-01T23:59:59.000Z
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 ...
Modeling Robot Dynamic Performance for Endpoint Force Control
Eppinger, Steven D.
1988-09-01T23:59:59.000Z
This research aims to understand the fundamental dynamic behavior of servo-controlled machinery in response to various types of sensory feedback. As an example of such a system, we study robot force control, a scheme ...
SIMULATING MARKET TRANSFORMATION DYNAMICS USING A HYBRID ENERGY ECONOMY MODEL
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
Multiscale Modeling of Process Dynamics and Microstructure Development...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of Process Dynamics and Microstructure Development in Laser-based Keyhole Welding and Additive Manufacturing Jun 05 2015 10:00 AM - 11:00 AM Wenda Tan, University of Utah, Salt...
Modeling the dynamics and depositional patterns of sandy rivers
Jerolmack, Douglas J
2006-01-01T23:59:59.000Z
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 ...
Calibration of CDO Tranches with the Dynamical Generalized-Poisson Loss Model
Brigo, Damiano
Calibration of CDO Tranches with the Dynamical Generalized-Poisson Loss Model (updated shortened, and consistent calibration to quoted index CDO tranches and tranchelets for several maturities is feasible, as we dynamics, investigating calibration improve- ments and stability. JEL classification code: G13. AMS
Brownian Dynamics Model of Excited-State Relaxation in Solutions of Conjugated Oligomers
Yaron, David
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
StankoviÃ¦, Aleksandar
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
A Formal Framework for Modeling and Analysis of System-Level Dynamic Power Management
Ha, Dong S.
A Formal Framework for Modeling and Analysis of System-Level Dynamic Power Management Shrirang, tlmartin, ha}@vt.edu Abstract Recent advances in Dynamic Power Management (DPM) tech- niques have resulted in designs that support a rich set of power management options, both at the hardware and software levels
Van den Hof, Paul
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
Gurson's plasticity coupled to damage as a CAP model for concrete compaction in dynamics
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
Model-based Trajectory Control of Robots with Pneumatic Actuator Dynamics
Tedrake, Russ
movements despite being equipped with actuators (human muscles) that have band- width limitations similar. Motion planning has been successfully applied to a number of dynamic legged robots [13Model-based Trajectory Control of Robots with Pneumatic Actuator Dynamics Ryuma Niiyama Abstract
Studies of crack dynamics in clay soil II. A physically based model for
Hoffmann, Heiko
; accepted 20 July 2004 Available online 23 August 2004 Abstract The temporal dynamics of soil structure are capable of treating water and solute transport within macro- pores and within the surrounding soil matrix, 1976; Gerke and van Genuchten, 1993; Jarvis, 1994). Assessing preferential flow requires information
RÃ¶der, Beate
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
Using beryllium-7 to assess cross-tropopause1 transport in global models2
Liu, Hongyu
1 Using beryllium-7 to assess cross-tropopause1 transport in global models2 3 Hongyu Liu1 , David B, MA13 14 Short Title: Beryllium-7 and cross-tropopause transport15 Index Terms: 0368 Troposphere Initiative (GMI) modeling framework the29 utility of cosmogenic beryllium-7 (7 Be), a natural aerosol tracer
Gastelum, Zoe N.; White, Amanda M.; Whitney, Paul D.; Gosink, Luke J.; Sego, Landon H.
2013-06-04T23:59:59.000Z
The Multi-Source Signatures for Nuclear Programs project, part of Pacific Northwest National Laboratory’s (PNNL) Signature Discovery Initiative, seeks to computationally capture expert assessment of multi-type information such as text, sensor output, imagery, or audio/video files, to assess nuclear activities through a series of Bayesian network (BN) models. These models incorporate knowledge from a diverse range of information sources in order to help assess a country’s nuclear activities. The models span engineering topic areas, state-level indicators, and facility-specific characteristics. To illustrate the development, calibration, and use of BN models for multi-source assessment, we present a model that predicts a country’s likelihood to participate in the international nuclear nonproliferation regime. We validate this model by examining the extent to which the model assists non-experts arrive at conclusions similar to those provided by nuclear proliferation experts. We also describe the PNNL-developed software used throughout the lifecycle of the Bayesian network model development.
A flow resistance model for assessing the impact of vegetation on flood routing mechanics
Katul, Gabriel
control in urban storm water runoff [Kirby et al., 2005], and linking tidal hydrodynamic forcing to flow and field studies. The proposed model asymptotically recovers the flow resistance formulation when the waterA flow resistance model for assessing the impact of vegetation on flood routing mechanics Gabriel G
An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC-
Bak, Claus Leth
An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC- HVDC, especially in case of connection of offshore wind power plants (OWPPs). Modelling challenges are faced Networks Jakob Glasdam, Lorenzo Zeni, Jesper Hjerrild, Lukasz Kocewiak, Bo Hesselbaek Wind Power
Environmental Modeling and Assessment (2005) 10:6379 DOI 10.1007/s10666-004-4267-z Springer 2005
Risbey, James S.
2005-01-01T23:59:59.000Z
Environmental Modeling and Assessment (2005) 10:6379 DOI 10.1007/s10666-004-4267-z Springer 2005 Application of a checklist for quality assistance in environmental modelling to an energy model James Risbey a present considerable challenges to develop and test. Uncertainty assessments of such models provide only
First Prev Next Last Go Back Full Screen Close Quit Model Assessment
Spang, Rainer
Â·First Â·Prev Â·Next Â·Last Â·Go Back Â·Full Screen Â·Close Â·Quit Model Assessment and Selection Axel Â·Prev Â·Next Â·Last Â·Go Back Â·Full Screen Â·Close Â·Quit Model Assessment and Selection 2 Topics Predictive Â· Restriction Â· Selection Â· Regularization #12;Â·First Â·Prev Â·Next Â·Last Â·Go Back Â·Full Screen Â·Close Â·Quit Model
Keppens, J; 10.1613/jair.1335
2011-01-01T23:59:59.000Z
The predominant knowledge-based approach to automated model construction, compositional modelling, employs a set of models of particular functional components. Its inference mechanism takes a scenario describing the constituent interacting components of a system and translates it into a useful mathematical model. This paper presents a novel compositional modelling approach aimed at building model repositories. It furthers the field in two respects. Firstly, it expands the application domain of compositional modelling to systems that can not be easily described in terms of interacting functional components, such as ecological systems. Secondly, it enables the incorporation of user preferences into the model selection process. These features are achieved by casting the compositional modelling problem as an activity-based dynamic preference constraint satisfaction problem, where the dynamic constraints describe the restrictions imposed over the composition of partial models and the preferences correspond to thos...
Fast Dynamic Simulation-Based Small Signal Stability Assessment and Control
Acharya, Naresh; Baone, Chaitanya; Veda, Santosh; Dai, Jing; Chaudhuri, Nilanjan; Leonardi, Bruno; Sanches-Gasca, Juan; Diao, Ruisheng; Wu, Di; Huang, Zhenyu; Zhang, Yu; Jin, Shuangshuang; Zheng, Bin; Chen, Yousu
2014-12-31T23:59:59.000Z
Power grid planning and operation decisions are made based on simulation of the dynamic behavior of the system. Enabling substantial energy savings while increasing the reliability of the aging North American power grid through improved utilization of existing transmission assets hinges on the adoption of wide-area measurement systems (WAMS) for power system stabilization. However, adoption of WAMS alone will not suffice if the power system is to reach its full entitlement in stability and reliability. It is necessary to enhance predictability with "faster than real-time" dynamic simulations that will enable the dynamic stability margins, proactive real-time control, and improve grid resiliency to fast time-scale phenomena such as cascading network failures. Present-day dynamic simulations are performed only during offline planning studies, considering only worst case conditions such as summer peak, winter peak days, etc. With widespread deployment of renewable generation, controllable loads, energy storage devices and plug-in hybrid electric vehicles expected in the near future and greater integration of cyber infrastructure (communications, computation and control), monitoring and controlling the dynamic performance of the grid in real-time would become increasingly important. The state-of-the-art dynamic simulation tools have limited computational speed and are not suitable for real-time applications, given the large set of contingency conditions to be evaluated. These tools are optimized for best performance of single-processor computers, but the simulation is still several times slower than real-time due to its computational complexity. With recent significant advances in numerical methods and computational hardware, the expectations have been rising towards more efficient and faster techniques to be implemented in power system simulators. This is a natural expectation, given that the core solution algorithms of most commercial simulators were developed decades ago, when High Performance Computing (HPC) resources were not commonly available.
Seagraves, Andrew Nathan
2010-01-01T23:59:59.000Z
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 ...
Dynamic soil-structure interaction-comparison of FEM model with experimental results
Srinivasan, Palanivel Rajan
2000-01-01T23:59:59.000Z
to represent twenty different laboratory experiments. The results of these models are compared with results available from extensive experimental dynamic testing on a geotechnical centrifuge. Though the various results from the finite element analysis...
Dynamic First-Principles Molecular-Scale Model for Solid Oxide Fuel Cells V. Hugo Schmidt
Dynamic First-Principles Molecular-Scale Model for Solid Oxide Fuel Cells V. Hugo Schmidt vs. current density i characteristics applies both to the Solid Oxide Fuel Cell (SOFC) and Solid
Wei, Zheng, S.M. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
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 ...
Optimal motion planning with the half-car dynamical model for autonomous high-speed driving
Jeon, Jeong hwan
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 ...
Coupled Modeling of Dynamic Reservoir/Well Interactions under Liquid-loading Conditions
Limpasurat, Akkharachai
2013-10-23T23:59:59.000Z
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...
A Nonlinear Continuous Time Optimal Control Model of Dynamic Pricing and Inventory Control with no
Adida, Elodie
time optimal control model for studying a dynamic pricing and inventory control problem for a make-to-stock of not introducing any approximation to the real setting: it provides the exact solution of the system. When taking
Building Dynamic Models of Service Compositions with Simulation of Provision Resources
Dustdar, Schahram
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
Dynamic modeling of three-phase upflow fixed-bed reactor including pore diffusion C. Julcoura
Paris-Sud XI, Université de
Dynamic modeling of three-phase upflow fixed-bed reactor including pore diffusion C. Julcoura , R-phase upflow fixed-bed reactor are investigated using a non-isothermal heterogeneous model including gas not limiting, so that the simplest model predicts accurately the transient reactor behavior. Keywords: fixed-bed
New trends in vehicle dynamics: from modelling to control. Olivier SENAME
Paris-Sud XI, Université de
New trends in vehicle dynamics: from modelling to control. Olivier SENAME GIPSA-lab - Department approaches such as H approach for Linear Parameter Varying systems and Model predictive control have shown methods for modelling and control of subsystems and of the vehicle. The session will be organized
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow
Wang, Chao-Yang
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow W-dimensional model is developed to simulate discharge of a primary lithium/thionyl chloride battery. The model to the first task with important examples of lead-acid,1-3 nickel-metal hydride,4-8 and lithium-based batteries
From "Stages" of Business Growth to a Dynamic States Model of Entrepreneurial Growth and Change
Mottram, Nigel
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
Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua)
Nikolaou, Michael
1 Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua for identification and validation of an empirical model for a helicon plasma reactor, on the basis of experimental manufacturing processes such as plasma etching, accurate models based on first principles may be developed
Learning Dynamic Models of Compartment Systems by Combining Symbolic Regression with Fuzzy Vector
Fernandez, Thomas
. 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
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models
Sarkar, Sudeep
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models Leonid V. Tsap finite element models. The method is based on the iterative analysis of the differences betweenÃPhysically-based vision, deformable models, nonrigid motion analysis, biomedical applications, finite element analysis. Ã¦
Incorporating carbon capture and storage technologies in integrated assessment models
and storage of CO2 from electric power plants. The electric power sector accounts for a substant a methodology for incorporating technologies into computable general equilibrium economic models and demonstrate; Climate; Technology; General equilibrium; Diffusion 1. Introduction Over the past century, technological
Common-Cause Failure Treatment in Event Assessment: Basis for a Proposed New Model
Dana Kelly; Song-Hua Shen; Gary DeMoss; Kevin Coyne; Don Marksberry
2010-06-01T23:59:59.000Z
Event assessment is an application of probabilistic risk assessment in which observed equipment failures and outages are mapped into the risk model to obtain a numerical estimate of the event’s risk significance. In this paper, we focus on retrospective assessments to estimate the risk significance of degraded conditions such as equipment failure accompanied by a deficiency in a process such as maintenance practices. In modeling such events, the basic events in the risk model that are associated with observed failures and other off-normal situations are typically configured to be failed, while those associated with observed successes and unchallenged components are assumed capable of failing, typically with their baseline probabilities. This is referred to as the failure memory approach to event assessment. The conditioning of common-cause failure probabilities for the common cause component group associated with the observed component failure is particularly important, as it is insufficient to simply leave these probabilities at their baseline values, and doing so may result in a significant underestimate of risk significance for the event. Past work in this area has focused on the mathematics of the adjustment. In this paper, we review the Basic Parameter Model for common-cause failure, which underlies most current risk modelling, discuss the limitations of this model with respect to event assessment, and introduce a proposed new framework for common-cause failure, which uses a Bayesian network to model underlying causes of failure, and which has the potential to overcome the limitations of the Basic Parameter Model with respect to event assessment.
Jorge L. Sarmiento - Princeton PI, Anand Gnanadesikan - Princeton Co-I, Nicolas Gruber - UCLA PI, Xin Jin - UCLA PostDoc, Robert Armstrong - SUNY /Stony Brook Consultant
2007-06-21T23:59:59.000Z
This final report summarizes research undertaken collaboratively between Princeton University, the NOAA Geophysical Fluid Dynamics Laboratory on the Princeton University campus, the State University of New York at Stony Brook, and the University of California, Los Angeles between September 1, 2000, and November 30, 2006, to do fundamental research on ocean iron fertilization as a means to enhance the net oceanic uptake of CO2 from the atmosphere. The approach we proposed was to develop and apply a suite of coupled physical-ecological-biogeochemical models in order to (i) determine to what extent enhanced carbon fixation from iron fertilization will lead to an increase in the oceanic uptake of atmospheric CO2 and how long this carbon will remain sequestered (efficiency), and (ii) examine the changes in ocean ecology and natural biogeochemical cycles resulting from iron fertilization (consequences). The award was funded in two separate three-year installments: • September 1, 2000 to November 30, 2003, for a project entitled “Ocean carbon sequestration by fertilization: An integrated biogeochemical assessment.” A final report was submitted for this at the end of 2003 and is included here as Appendix 1. • December 1, 2003 to November 30, 2006, for a follow-on project under the same grant number entitled “Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models.” This report focuses primarily on the progress we made during the second period of funding subsequent to the work reported on in Appendix 1. When we began this project, we were thinking almost exclusively in terms of long-term fertilization over large regions of the ocean such as the Southern Ocean, with much of our focus being on how ocean circulation and biogeochemical cycling would interact to control the response to a given fertilization scenario. Our research on these types of scenarios, which was carried out largely during the first three years of our project, led to several major new insights on the interaction between ocean biogeochemistry and circulation. This work, which is described in the following Section II on “Large scale fertilization,” has continued to appear in the literature over the past few years, including two high visibility papers in Nature. Early on in the first three years of our project, it became clear that small "patch-scale" fertilizations over limited regions of order 100 km diameter were much more likely than large scale fertilization, and we carried out a series of idealized patch fertilization simulations reported on in Gnanadesikan et al. (2003). Based on this paper and other results we had obtained by the end of our first three-year grant, we identified a number of important issues that needed to be addressed in the second three-year period of this grant. Section III on “patch fertilization” discusses the major findings of this phase of our research, which is described in two major manuscripts that will be submitted for publication in the near future. This research makes use of new more realistic ocean ecosystem and iron cycling models than our first paper on this topic. We have several major new insights into what controls the efficiency of iron fertilization in the ocean. Section IV on “model development” summarizes a set of papers describing the progress that we made on improving the ecosystem models we use for our iron fertilization simulations.
Huang, Zhenyu; Du, Pengwei; Kosterev, Dmitry; Yang, Steve
2013-05-01T23:59:59.000Z
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.
Characteristics of identifying linear dynamic models from impulse response data using Prony analysis
Trudnowski, D.J.
1992-12-01T23:59:59.000Z
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.
Characteristics of identifying linear dynamic models from impulse response data using Prony analysis
Trudnowski, D.J.
1992-12-01T23:59:59.000Z
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.
Sleep Dynamics and Seizure Control in a Mesoscale Cortical Model
Lopour, Beth Ann
2009-01-01T23:59:59.000Z
Contributions . . . . . . . . . 2 Mesoscale Cortical Modelstates in h e from the mesoscale cortical model, here- afterand Seizure Control in a Mesoscale Cortical Model by Beth
Dynamics of the Oil Transition: Modeling Capacity, Costs, and Emissions
Brandt, Adam R.; Farrell, Alexander E.
2008-01-01T23:59:59.000Z
market, allowing our model to focus on the supply of crude oil andterms of the model equations [7]). The oil market in ROMEO
Modeling the star formation in galaxies using the Chemo - dynamical SPH code
Peter Berczik
2000-07-19T23:59:59.000Z
A new Chemo - Dynamical Smoothed Particle Hydrodynamic (CD - SPH) code is presented. The disk galaxy is described as a multi - fragmented gas and star system, embedded in a cold dark matter halo. The star formation (SF) process, SNII, SNIa and PN events as well as chemical enrichment of gas have been considered within the framework of the standard SPH model. Using this model we describe the dynamical and chemical evolution of triaxial disk - like galaxies. It is found that such approach provides a realistic description of the process of formation, chemical and dynamical evolution of disk galaxies over a cosmological timescale.
Mixed Layer Mesoscales for OGCMs: Model development and assessment with T/P, WOCE and Drifter data
Canuto, V M; Leboissetier, A
2011-01-01T23:59:59.000Z
We present a model for mixed layer (ML) mesoscale (M) fluxes of an arbitrary tracer in terms of the resolved fields (mean tracer and mean velocity). The treatment of an arbitrary tracer, rather than only buoyancy, is necessary since OGCMs time step T, S, CO2, etc and not buoyancy. The particular case of buoyancy is used to assess the model results. The paper contains three parts: derivation of the results, discussion of the results and assessment of the latter using, among others, WOCE, T/P and Drifter data. Derivation. To construct the M fluxes, we first solve the ML M dynamic equations for the velocity and tracer M fields. The goal of the derivation is to emphasize the different treatments of the non-linear terms in the adiabatic vs. diabatic ocean (deep ocean vs. mixed layer). Results. We derive analytic expressions for the following variables: a) vertical and horizontal M fluxes of an arbitrary tracer, b) M diffusivity in terms of the EKE, c) surface value of the EKE in terms of the vertical M buoyancy fl...
Wang, Shaobu; Lu, Shuai; Zhou, Ning; Lin, Guang; Elizondo, Marcelo A.; Pai, M. A.
2014-09-04T23:59:59.000Z
In interconnected power systems, dynamic model reduction can be applied on generators outside the area of interest to mitigate the computational cost with transient stability studies. This paper presents an approach of deriving the reduced dynamic model of the external area based on dynamic response measurements, which comprises of three steps, dynamic-feature extraction, attribution and reconstruction (DEAR). In the DEAR approach, a feature extraction technique, such as singular value decomposition (SVD), is applied to the measured generator dynamics after a disturbance. Characteristic generators are then identified in the feature attribution step for matching the extracted dynamic features with the highest similarity, forming a suboptimal ‘basis’ of system dynamics. In the reconstruction step, generator state variables such as rotor angles and voltage magnitudes are approximated with a linear combination of the characteristic generators, resulting in a quasi-nonlinear reduced model of the original external system. Network model is un-changed in the DEAR method. Tests on several IEEE standard systems show that the proposed method gets better reduction ratio and response errors than the traditional coherency aggregation methods.
Comparative evaluation of life cycle assessment models for solid waste management
Winkler, Joerg [Institute for Waste Management and Contaminated Sites Treatment, TU Dresden Faculty of Forestry, Geo and Hydro Sciences, Pratzschwitzer Str. 15, 01796 Pirna (Germany); Bilitewski, Bernd [Institute for Waste Management and Contaminated Sites Treatment, TU Dresden Faculty of Forestry, Geo and Hydro Sciences, Pratzschwitzer Str. 15, 01796 Pirna (Germany)], E-mail: abfall@rcs.urz.tu-dresden.de
2007-07-01T23:59:59.000Z
This publication compares a selection of six different models developed in Europe and America by research organisations, industry associations and governmental institutions. The comparison of the models reveals the variations in the results and the differences in the conclusions of an LCA study done with these models. The models are compared by modelling a specific case - the waste management system of Dresden, Germany - with each model and an in-detail comparison of the life cycle inventory results. Moreover, a life cycle impact assessment shows if the LCA results of each model allows for comparable and consecutive conclusions, which do not contradict the conclusions derived from the other models' results. Furthermore, the influence of different level of detail in the life cycle inventory of the life cycle assessment is demonstrated. The model comparison revealed that the variations in the LCA results calculated by the models for the case show high variations and are not negligible. In some cases the high variations in results lead to contradictory conclusions concerning the environmental performance of the waste management processes. The static, linear modelling approach chosen by all models analysed is inappropriate for reflecting actual conditions. Moreover, it was found that although the models' approach to LCA is comparable on a general level, the level of detail implemented in the software tools is very different.
Chapter 18: Understanding the Developing Cellulosic Biofuels Industry through Dynamic Modeling
Newes, E.; Inman, D.; Bush, B.
2011-01-01T23:59:59.000Z
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.
Bair, Wyeth
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
A Preliminary Study to Assess Model Uncertainties in Fluid Flows
Delchini, Marc Olivier
2011-08-08T23:59:59.000Z
of the fluid. ? The sound speed, c, is assumed to be constant even if it usually depends on the temperature and the pressure. This is a good approximation for liquids but not for gases. The sound speed is reactor-dependent. ? The Equation Of State (EOS... to the temperature. This parameter is assumed constant in this model. 7 ? ???P is the dilatation of the density due to the pressure. This parameter is also assumed constant but is different for different sound speeds. Its expression is as follows: ?? ?P = 1...
Humanoid Walking Robot: Modeling, Inverse Dynamics, and Gain Scheduling Control
Williams II, Robert L.
and Robert L. Williams II Department of Mechanical Engineering Ohio University, Athens, OH 45701 Revised trajectories, recorded from real human walking cycle data. Kinematic and dynamic analysis is discussed. This analysis is accompanied by a comparison with available experimental data. Finally, an inverse plant
Prof. Alessandro De Luca Dynamic model of robots
De Luca, Alessandro
, 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
Dynamic Model Validation of PV Inverters Under Short-Circuit Conditions: Preprint
Muljadi, E.; Singh, M.; Bravo, R.; Gevorgian, V.
2013-03-01T23:59:59.000Z
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.
Robertson, A.W.; Ghil, M.; Kravtsov, K.; Smyth, P.J.
2011-04-08T23:59:59.000Z
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.
Kravtsov, S.; Robertson, A. W.; Ghil, M.; Smyth, P. J.
2011-04-08T23:59:59.000Z
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.
SOCIAL MODELING IN ASSESSEMENT OF A STATE’S PROPENSITY FOR NUCLEAR PROLIFERATION
Dalton, Angela C.; Whitney, Paul D.; Coles, Garill A.; Brothers, Alan J.
2011-07-17T23:59:59.000Z
This paper presents approach for assessing a State’s propensity for nuclear weapons proliferation using social modeling. We supported this modeling by first reviewing primarily literature by social scientists on factors related to the propensity of a State to proliferation and by leveraging existing relevant data compiled by social scientists. We performed a number of validation tests on our model including one that incorporates use of benchmark data defining the proliferation status of countries in the years between 1945 and 2000. We exercise the BN model against a number of country cases representing different perceived levels of proliferation risk. We also describe how the BN model could be further refined to be a proliferation assessment tool for decision making.
Liese, Eric [U.S. DOE; Zitney, Stephen E. [U.S. DOE
2013-01-01T23:59:59.000Z
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.
A nonlinear dynamic model of a once-through, helical-coil steam generator
Abdalla, M.A. [Oak Ridge Inst. for Science and Education, TN (United States)
1993-07-01T23:59:59.000Z
A dynamic model of a once-through, helical-coil steam generator is presented. The model simulates the advanced liquid metal reactor superheated cycle steam generator with a four-region, moving-boundary, drift-flux model. The model is described by a set of nonlinear differential equations derived from the fundamental equations of conversation of mass, energy, and momentum. Sample results of steady-state and transient calculations are presented.
Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers
David W. Gandy; John P. Shingledecker
2011-04-11T23:59:59.000Z
Forced outages and boiler unavailability in conventional coal-fired fossil power plants is most often caused by fireside corrosion of boiler waterwalls. Industry-wide, the rate of wall thickness corrosion wastage of fireside waterwalls in fossil-fired boilers has been of concern for many years. It is significant that the introduction of nitrogen oxide (NOx) emission controls with staged burners systems has increased reported waterwall wastage rates to as much as 120 mils (3 mm) per year. Moreover, the reducing environment produced by the low-NOx combustion process is the primary cause of accelerated corrosion rates of waterwall tubes made of carbon and low alloy steels. Improved coatings, such as the MCrAl nanocoatings evaluated here (where M is Fe, Ni, and Co), are needed to reduce/eliminate waterwall damage in subcritical, supercritical, and ultra-supercritical (USC) boilers. The first two tasks of this six-task project-jointly sponsored by EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)-have focused on computational modeling of an advanced MCrAl nanocoating system and evaluation of two nanocrystalline (iron and nickel base) coatings, which will significantly improve the corrosion and erosion performance of tubing used in USC boilers. The computational model results showed that about 40 wt.% is required in Fe based nanocrystalline coatings for long-term durability, leading to a coating composition of Fe-25Cr-40Ni-10 wt.% Al. In addition, the long term thermal exposure test results further showed accelerated inward diffusion of Al from the nanocrystalline coatings into the substrate. In order to enhance the durability of these coatings, it is necessary to develop a diffusion barrier interlayer coating such TiN and/or AlN. The third task 'Process Advanced MCrAl Nanocoating Systems' of the six-task project jointly sponsored by the Electric Power Research Institute, EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)- has focused on processing of advanced nanocrystalline coating systems and development of diffusion barrier interlayer coatings. Among the diffusion interlayer coatings evaluated, the TiN interlayer coating was found to be the optimum one. This report describes the research conducted under the Task 3 workscope.
Gedeon, Tomas
, from those appearing in physiology and ecology to Earth systems modeling, often experience critical
Synchronized Phasor Data for Analyzing Wind Power Plant Dynamic Behavior and Model Validation
Wan, Y. H.
2013-01-01T23:59:59.000Z
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.
Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model
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
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.
SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models
Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II
1992-09-01T23:59:59.000Z
Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community.
A Fiber Tracking Method for Building Patient Specific Dynamic Musculoskeletal Models from
Gilles, Benjamin
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
Generalized models as a universal approach to the analysis of nonlinear dynamical systems
Thilo Gross; Ulrike Feudel
2006-01-29T23:59:59.000Z
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.
Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel
Victoria, University of
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
Dynamic Topic Models David M. Blei BLEI@CS.PRINCETON.EDU
Blei, David M.
Dynamic Topic Models David M. Blei BLEI@CS.PRINCETON.EDU Computer Science Department, Princeton patterns of words in document collec- tions using hierarchical probabilistic models (Blei et al., 2003; McCallum et al., 2004; Rosen-Zvi et al., 2004; Grif- fiths and Steyvers, 2004; Buntine and Jakulin, 2004; Blei
Affinely-rigid body and oscillatory dynamical models on GL(2,R)
Agnieszka Martens; Jan J. S?awianowski
2010-11-23T23:59:59.000Z
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.
Pricing Bivariate Option under GARCH-GH Model with Dynamic Copula: Application for
Paris-Sud XI, Université de
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
Modelling propagation of sinkhole, in both slow and dynamic modes, using the UDEC computer code.
Paris-Sud XI, UniversitÃ© de
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
Phase Field Dynamic Modelling of Shape Memory Alloys Based on Isogeometric Analysis
Gomez, Hector
Phase Field Dynamic Modelling of Shape Memory Alloys Based on Isogeometric Analysis Rakesh Dhote1 transformations, phase-field model, Ginzburg-Landau theory, nonlinear thermo-elasticity. Abstract. Shape Memory. Introduction Shape Memory Alloys have attracted considerable attention of physicists, engineers and mathemati
Dynamics of cerebral blood flow regulation explained using a lumped parameter model
Olufsen, Mette Sofie
Dynamics of cerebral blood flow regulation explained using a lumped parameter model METTE S, and Harvard Medical School, Boston, Massachusetts 02131 Received 22 May 2001; accepted in final form 10 regulation explained using a lumped parameter model. Am J Physiol Regulatory Integra- tive Comp Physiol 282
Analysis of a Darcy flow model with a dynamic pressure saturation relation \\Lambda
Hulshof, Joost
equations modelling the flow. In the standard approach for two phase flows, such as oilwater or airwater mixtures, one combines the mass conservation equations and Darcy's law for the separate phasesAnalysis of a Darcy flow model with a dynamic pressure saturation relation \\Lambda Josephus Hulshof
Hammes-Schiffer, Sharon
Proton-coupled electron transfer reactions in solution: Molecular dynamics with quantum transitions A general minimal model for proton-coupled electron transfer PCET reactions in solution is presented. This model consists of three coupled degrees of freedom that represent an electron, a proton, and a solvent
Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics
Grilli, StÃ©phan T.
Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics Hong Gun SungÂ½ and Stephan T. GrilliÂ¾ Â½ Korea Ocean Research and Development Institute, Daejeon model fully nonlinear free surface waves caused by a translating dis- turbance made of a pressure patch
Modeling Red Blood Cell and Iron Dynamics in Patients with Chronic Kidney Disease
Modeling Red Blood Cell and Iron Dynamics in Patients with Chronic Kidney Disease H. T. Banks1, that stimulates red blood cell (RBC) production. Without intervention, patients suffer from anemia. Patients treatment. Keywords: mathematical model, mathematical biology, erythropoiesis, erythrocyte, red blood cell
A 3D dynamical biomechanical tongue model to study speech motor control
Paris-Sud XI, Université de
- 1 - A 3D dynamical biomechanical tongue model to study speech motor control Jean-Michel Gérard1 about speech motor control. Tissue elastic properties are accounted for in Finite Element Modeling (FEM shape are presented and analyzed. #12;- 3 - I.Introduction The study of human motor control implies
Data-driven Modeling of Metal-oxide Sensors with Dynamic Bayesian Networks
Gutierrez-Osuna, Ricardo
to model the transient response of MOX sensors modulated with a sequence of voltage steps. Analytical models of MOX sensors are usually built based on the physico-chemical properties of the sensing materials. Our results show that DBNs can accurately predict the dynamic response of MOX sensors, as well
ForPeerReview Drug user dynamics: a compartmental model of drug users
Triolo, Livio
ForPeerReview Only Drug user dynamics: a compartmental model of drug users for scenario analyses Journal: Drugs: Education, Prevention & Policy Manuscript ID: CDEP-2012-0094.R1 Manuscript Type: Original papers Keywords: Drug use, Epidemics, Compartmental modeling, Scenario analysis, Evaluation, Drug policy
A Diffusion Model in Population Genetics with Mutation and Dynamic Fitness
O'Leary, Michael
A Diffusion Model in Population Genetics with Mutation and Dynamic Fitness Mike O'Leary Department of Mathematics Towson University PDE Seminar Vanderbilt University November 2008 Mike O'Leary (Towson University are joint with Judith Miller, Georgetown University. Mike O'Leary (Towson University) A Diffusion Model
Simulation of aerosol dynamics: a comparative review of mathematical models
Seigneur, C.; Hudischewskyj, A.B.; Seinfeld, J.H.; Whitby, K.T.; Whitby, E.R.
1986-01-01T23:59:59.000Z
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.
Representation of Dormant and Active Microbial Dynamics for Ecosystem Modeling
Wang, Gangsheng [ORNL; Mayes, Melanie [ORNL; Gu, Lianhong [ORNL; Schadt, Christopher Warren [ORNL
2014-01-01T23:59:59.000Z
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.
Dynamic Models for Wind Turbines and Wind Power Plants
Singh, M.; Santoso, S.
2011-10-01T23:59:59.000Z
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.
Dynamic Conditional Correlation - A Simple Class of Multivariate GARCH Models
Engle, Robert F
2000-01-01T23:59:59.000Z
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
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...
LECTURES ON DYNAMICS IN MODELS OF COARSENING AND COAGULATION
bath 11 2.4 Mean-field model of domain growth--the Gallay-Mielke transform 13 2.5 Proof of universal
A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering
Robock, Alan
1 A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering Normal University, Beijing, China. 9 School of Engineering and Applied Sciences, Harvard University levels. G1 involves a reduction in solar irradiance to counteract the radiative forcing5 in abrupt4xCO2
Washington at Seattle, University of
Assessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using July 15, 1999 #12;Abstract Much of the evidence for health e ects of particulate air pollution has come standards for ambient air pollutants to protect the public from adverse e ects. Much of the evidence for air
A System for 3D Error Visualization and Assessment of Digital Elevation Models
Gousie, Michael B.
A System for 3D Error Visualization and Assessment of Digital Elevation Models Michael B. Gousie that displays a DEM and possible errors in 3D, along with its associated contour or sparse data and detail. The cutting tool is semi-transparent so that the profile is seen in the context of the 3D surface
Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1)
that the active power supplied from the first large 160 MW offshore wind farm in this system, Horns Rev today). Figure 1. Power generation of Horns Rev offshore wind farm and onshore turbines, January 18 2005Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1) , P. Sørensen1) , A
Use of models and observations to assess trends in the 19502005 water balance and climate
) was about 50% of normal during 20002001. The ensuing drought-related water shortage led to seriousUse of models and observations to assess trends in the 19502005 water balance and climate of Upper-driven interannual (and longer) variability is evident. Evaporation and the other components of the water balance
Refinement of weed risk assessments for biofuels using Camelina sativa as a model species
Peterson, Robert K. D.
Refinement of weed risk assessments for biofuels using Camelina sativa as a model species Philip B and Environmental Sciences, Montana State University, PO Box 173120, Bozeman, MT 59717-3120, USA Summary 1. Biofuel. However, concerns have been raised on the invasiveness of biofuel feedstocks. Estimating invasion
ASSESSMENT OF THE MODELS FOR THE ESTIMATION OF THE CO2 RELEASES TOXIC EFFECTS
Boyer, Edmond
the global warming due to high concentration of CO2 in the atmosphere. However, in case of massive accidental to specific properties regarding its triple point. Then, this CO2 flakes creation may be followed1 ASSESSMENT OF THE MODELS FOR THE ESTIMATION OF THE CO2 RELEASES TOXIC EFFECTS Frédéric Antoine
NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled
Meissner, Katrin Juliane
NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled of ice shelves and their progenitor ice sheets. To explore the magnitude of surface melt occurring over modern ice shelves and ice sheets in a climate scenario forced by anthropogenic emissions of carbon
Pedersen, Tom
Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Dissertation Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines) #12;iii ABSTRACT This thesis examines methods for designing and analyzing kinetic turbines based
Victoria, University of
Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Thesis Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines examines methods for designing and analyzing kinetic turbines based on blade element momentum (BEM) theory
On preparation of viscous pore fluids for dynamic centrifuge modelling
Adamidis, O.; Madabhushi, S. P. G.
2014-11-21T23:59:59.000Z
dynamic cen- trifuge tests, the use of water as pore fluid can limit the generation of excess pore pressures in sand formations below gravel embankments, lowering the recorded crest settlement signif- icantly. Chian and Madabhushi [2010] exam- ined... with changing 4 1.2 1.6 2 2.4 2.8 3.2 0 40 80 120 160 200 Concentration [%] V is co si ty [m P a · s] measurements at 20?C best fit (8th order) best fit (power law) Stewart et al. [1998] Figure 2: Viscosity change with concentration 1.2 1.6 2 2.4 2.8 3.2 1...
Modeling Temporal Activity Patterns in Dynamic Social Networks
Raghavan, Vasanthan; Galstyan, Aram; Tartakovsky, Alexander G
2013-01-01T23:59:59.000Z
The focus of this work is on developing probabilistic models for user activity in social networks by incorporating the social network influence as perceived by the user. For this, we propose a coupled Hidden Markov Model, where each user's activity evolves according to a Markov chain with a hidden state that is influenced by the collective activity of the friends of the user. We develop generalized Baum-Welch and Viterbi algorithms for model parameter learning and state estimation for the proposed framework. We then validate the proposed model using a significant corpus of user activity on Twitter. Our numerical studies show that with sufficient observations to ensure accurate model learning, the proposed framework explains the observed data better than either a renewal process-based model or a conventional uncoupled Hidden Markov Model. We also demonstrate the utility of the proposed approach in predicting the time to the next tweet. Finally, clustering in the model parameter space is shown to result in dist...
Dynamical Models Explaining Social Balance and Evolution of Cooperation
De Leenheer, Patrick
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
Modeling Dynamic Receptive Field Changes in Primary Visual Cortex Using Inhibitory Learning
1997-01-01T23:59:59.000Z
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...
Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System
Stenner, Robert D.; Hadley, Donald L.; Armstrong, Peter R.; Buck, John W.; Hoopes, Bonnie L.; Janus, Michael C.
2001-03-01T23:59:59.000Z
Indoor air quality effects on human health are of increasing concern to public health agencies and building owners. The prevention and treatment of 'sick building' syndrome and the spread of air-borne diseases in hospitals, for example, are well known priorities. However, increasing attention is being directed to the vulnerability of our public buildings/places, public security and national defense facilities to terrorist attack or the accidental release of air-borne biological pathogens, harmful chemicals, or radioactive contaminants. The Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System (IA-NBC-HMAS) was developed to serve as a health impact analysis tool for use in addressing these concerns. The overall goal was to develop a user-friendly fully functional prototype Health Modeling and Assessment system, which will operate under the PNNL FRAMES system for ease of use and to maximize its integration with other modeling and assessment capabilities accessible within the FRAMES system (e.g., ambient air fate and transport models, water borne fate and transport models, Physiologically Based Pharmacokinetic models, etc.). The prototype IA-NBC-HMAS is designed to serve as a functional Health Modeling and Assessment system that can be easily tailored to meet specific building analysis needs of a customer. The prototype system was developed and tested using an actual building (i.e., the Churchville Building located at the Aberdeen Proving Ground) and release scenario (i.e., the release and measurement of tracer materials within the building) to ensure realism and practicality in the design and development of the prototype system. A user-friendly "demo" accompanies this report to allow the reader the opportunity for a "hands on" review of the prototype system's capability.
Ris-R-1400(EN) Dynamic wind turbine models in power
RisÃ¸-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
Annual report, October 1980-September 1981 Multimedia radionuclide exposure assessment modeling.
Whelan, G.; Onishi, Y.; Simmons, C.S.; Horst, T.W.; Gupta, S.K.; Orgill, M.M.; Newbill, C.A.
1982-12-01T23:59:59.000Z
Pacific Northwest Laboratory (PNL) and Los Alamos National Laboratory (LANL) are jointly developing a methodology for assessing exposures of the air, water, and plants to radionuclides as part of an overall development effort of a radionuclide disposal site evaluation methodology. Work in FY-1981 continued the development of the Multimedia Contaminant Environmental Exposure Assessment (MCEA) methodology and initiated an assessment of radionuclide migration in Los Alamos and Pueblo Canyons, New Mexico, using the methodology. The AIRTRAN model was completed, briefly tested, and documented. In addition, a literature search for existing validation data for AIRTRAN was performed. The feasibility and advisability of including the UNSAT moisture flow model as a submodel of the terrestrial code BIOTRAN was assessed. A preliminary application of the proposed MCEA methodology, as it related to the Mortandad-South Mortandad Canyon site in New Mexico is discussed. This preliminary application represented a scaled-down version of the methodology in which only the terrestrial, overland, and surface water components were used. An update describing the progress in the assessment of radionuclide migration in Los Alamos and Pueblo Canyons is presented. 38 references, 47 figures, 11 tables.
Advanced Modeling of Renewable Energy Market Dynamics: May 2006
Evans, M.; Little, R.; Lloyd, K.; Malikov, G.; Passolt, G.; Arent, D.; Swezey, B.; Mosey, G.
2007-08-01T23:59:59.000Z
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.
. Assigning values to these parameters is a time-dependent process, captured as the evolution of a dynamical categorization task due to the inherent stabilization property of the dynamical formalism. Dynamic Model Coupled-field Dynamic Model · Two coupled dynamic fields, one corresponding to DA, the other to TA, each with activation
Tsiotras, Panagiotis
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
Denny, Mark
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
Huang, Xun
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
Vector-Based Dynamic Modeling and Control of the Quattro Parallel Robot by means of Leg Orientations
Paris-Sud XI, Université de
Vector-Based Dynamic Modeling and Control of the Quattro Parallel Robot by means of Leg-speed control of a parallel robot is to define an efficient dynamic model. It is usually not easy to have by a calibrated camera, in the sense of solving the entire control-oriented (hard) modeling problem, both
Düring, Bertram
2015-01-01T23:59:59.000Z
We propose and investigate different kinetic models for opinion formation, when the opinion formation process depends on an additional independent variable, e.g. a leadership or a spatial variable. More specifically, we consider:(i) opinion dynamics under the effect of opinion leadership, where each individual is characterised not only by its opinion, but also by another independent variable which quantifies leadership qualities; (ii) opinion dynamics modelling political segregation in the `The Big Sort', a phenomenon that US citizens increasingly prefer to live in neighbourhoods with politically like-minded individuals. Based on microscopic opinion consensus dynamics such models lead to inhomogeneous Boltzmann-type equations for the opinion distribution. We derive macroscopic Fokker-Planck-type equations in a quasi-invariant opinion limit and present results of numerical experiments.