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1

A hierarchical fracture model for the iterative multiscale finite volume method  

Science Conference Proceedings (OSTI)

An iterative multiscale finite volume (i-MSFV) method is devised for the simulation of multiphase flow in fractured porous media in the context of a hierarchical fracture modeling framework. Motivated by the small pressure change inside highly conductive ... Keywords: Fractured porous media, Hierarchical fractured modeling, Iterative multiscale finite volume, Iterative multiscale methods, Multiscale finite volume, Multiscale fracture modeling, Multiscale methods

Hadi Hajibeygi; Dimitris Karvounis; Patrick Jenny

2011-10-01T23:59:59.000Z

2

Filtering Partially Observed Multiscale Systems with Heterogeneous Multiscale Methods–Based Reduced Climate Models  

Science Conference Proceedings (OSTI)

This paper presents a fast reduced filtering strategy for assimilating multiscale systems in the presence of observations of only the macroscopic (or large scale) variables. This reduced filtering strategy introduces model errors in estimating the ...

Emily L. Kang; John Harlim

2012-03-01T23:59:59.000Z

3

Modeling complex wells with the multi-scale finite-volume method  

Science Conference Proceedings (OSTI)

In this paper, an extension of the multi-scale finite-volume (MSFV) method is devised, which allows to simulate flow and transport in reservoirs with complex well configurations. The new framework fits nicely into the data structure of the original MSFV ... Keywords: Gravity, Heterogeneous media, Multi-phase flow, Multi-scale finite-volume, Porous media, Well modeling

Patrick Jenny; Ivan Lunati

2009-02-01T23:59:59.000Z

4

Adaptive iterative multiscale finite volume method  

Science Conference Proceedings (OSTI)

The multiscale finite volume (MSFV) method is a computationally efficient numerical method for the solution of elliptic and parabolic problems with heterogeneous coefficients. It has been shown for a wide range of test cases that the MSFV results are ... Keywords: Adaptive multiscale method, Elliptic problem, Infrequently localization improvement, Iterative multiscale finite-volume method, Iterative multiscale method, Multiphase flow, Multiscale finite-volume method, Multiscale method, Porous media

Hadi Hajibeygi; Patrick Jenny

2011-02-01T23:59:59.000Z

5

Multiscale Modeling of Interfacial Environments around ...  

Science Conference Proceedings (OSTI)

Multiscale Modeling of Interfacial Environments around Carbon Nanotubes. ... can be significantly affected by the interfacial environment at the ...

2013-02-13T23:59:59.000Z

6

Design and Implementation of Scientific Software Components to Enable Multiscale Modeling: The Effective Fragment Potential (QM/EFP) Method  

SciTech Connect

The design and development of scientific software components to provide an interface to the effective fragment potential (EFP) methods are reported. Multiscale modeling of physical and chemical phenomena demands the merging of software packages developed by research groups in significantly different fields. Componentization offers an efficient way to realize new high performance scientific methods by combining the best models available in different software packages without a need for package readaptation after the initial componentization is complete. The EFP method is an efficient electronic structure theory based model potential that is suitable for predictive modeling of intermolecular interactions in large molecular systems, such as liquids, proteins, atmospheric aerosols, and nanoparticles, with an accuracy that is comparable to that of correlated ab initio methods. The developed components make the EFP functionality accessible for any scientific component-aware software package. The performance of the component is demonstrated on a protein interaction model, and its accuracy is compared with results obtained with coupled cluster methods.

Gaenko, Alexander [Ames Laboratory; Windus, Theresa L. [Ames Laboratory; Sosonkina, Masha [Ames Laboratory; Gordon, Mark S. [Ames Laboratory

2012-10-19T23:59:59.000Z

7

A stochastic variational multiscale method for diffusion in heterogeneous random media  

Science Conference Proceedings (OSTI)

A stochastic variational multiscale method with explicit subgrid modelling is provided for numerical solution of stochastic elliptic equations that arise while modelling diffusion in heterogeneous random media. The exact solution of the governing equations ... Keywords: generalized polynomial chaos, multiscale finite element, operator upscaling, stochastic diffusion, subgrid modelling, variational multiscale

Badrinarayanan Velamur Asokan; Nicholas Zabaras

2006-11-01T23:59:59.000Z

8

MULTISCALE THERMOHYDROLOGIC MODEL  

Science Conference Proceedings (OSTI)

The intended purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. The goal of the MSTHM is to predict a reasonable range of possible thermal-hydrologic conditions within the emplacement drift. To be reasonable, this range includes the influence of waste-package-to-waste-package heat output variability relevant to the license application design, as well as the influence of uncertainty and variability in the geologic and hydrologic conditions relevant to predicting the thermal-hydrologic response in emplacement drifts. This goal is quite different from the goal of a model to predict a single expected thermal-hydrologic response. As a result, the development and validation of the MSTHM and the associated analyses using this model are focused on the goal of predicting a reasonable range of thermal-hydrologic conditions resulting from parametric uncertainty and waste-package-to-waste-package heat-output variability. Thermal-hydrologic conditions within emplacement drifts depend primarily on thermal-hydrologic conditions in the host rock at the drift wall and on the temperature difference between the drift wall and the drip-shield and waste-package surfaces. Thus, the ability to predict a reasonable range of relevant in-drift MSTHM output parameters (e.g., temperature and relative humidity) is based on valid predictions of thermal-hydrologic processes in the host rock, as well as valid predictions of heat-transfer processes between the drift wall and the drip-shield and waste-package surfaces. Because the invert contains crushed gravel derived from the host rock, the invert is, in effect, an extension of the host rock, with thermal and hydrologic properties that have been modified by virtue of the crushing (and the resulting geometry of the gravel grains). Thus, given that reasonable invert properties are applied, the ability to predict a reasonable range of relevant MSTHM output parameters for the invert are based on valid predictions of thermal-hydrologic processes in the host rock. The MSTHM calculates the following thermal-hydrologic parameters: temperature, relative humidity, liquid-phase saturation, evaporation rate, air-mass fraction, gas-phase pressure, capillary pressure, and liquid- and gas-phase fluxes. The thermal-hydrologic parameters used to support ''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' are identified in Table 1-1. The thermal-hydrologic parameters are determined as a function of position along each of the emplacement drifts and as a function of waste package type. These parameters are determined at various reference locations within the emplacement drifts, including the waste package and drip-shield surfaces and in the invert. The parameters are also determined at various defined locations in the adjoining host rock.

T. Buscheck

2005-07-07T23:59:59.000Z

9

Well Models for Mimetic Finite Difference Methods and Improved Representation of Wells inMultiscale Methods.  

E-Print Network (OSTI)

??In reservoir simulation, the modeling and the representation of wells are critical factors. The standard approach for well modeling is to couple the well to… (more)

Ligaarden, Ingeborg Skjelkvåle

2008-01-01T23:59:59.000Z

10

Multiscale Materials Modeling of Condensed Matter - TMS  

Science Conference Proceedings (OSTI)

Nov 29, 2007 ... The following presentations from MMM 2007, the International Max-Planck Workshop on Multiscale Materials Modeling of Condensed Matter, ...

11

PI-23: Multiscale Computational Modeling of Adsorption  

Science Conference Proceedings (OSTI)

Presentation Title, PI-23: Multiscale Computational Modeling of Adsorption ... catalytic cracking, as well as the low pressure storage of natural gas or hydrogen.

12

Multi-Scale Kernel Latent Variable Models for Nonlinear Time Series Pattern Matching  

Science Conference Proceedings (OSTI)

In this paper we propose a method for nonlinear time series pattern matching: "Multi-Scale Kernel Latent Variable (MSKLV) models". The pattern matching methodology includes multi-scale analysis using wavelet decomposition of time series and finding latent ...

B. Venkataramana Kini; C. Chandra Sekhar

2008-01-01T23:59:59.000Z

13

A Multilevel Multiscale Mimetic (M3) Method for an Anisotropic Infiltration Problem  

Science Conference Proceedings (OSTI)

Modeling of multiphase flow and transport in highly heterogeneous porous media must capture a broad range of coupled spatial and temporal scales. Recently, a hierarchical approach dubbed the Multilevel Multiscale Mimetic (M3) method, was developed ... Keywords: heterogeneous porous media, hierarchical, infiltration, multiscale, two-phase flow

Konstantin Lipnikov; David Moulton; Daniil Svyatskiy

2009-05-01T23:59:59.000Z

14

Multi-scale Modelling Applied to Non Linear Constitutive Equations  

Science Conference Proceedings (OSTI)

A Continuum General Noise Brownian Thermostat with Applications to Film Morphology · A Multiscale, Nonlinear, Modeling Framework Enabling the Design and ...

15

Multi-Scale Modeling to Predict Properties of Thermoplastic ...  

Science Conference Proceedings (OSTI)

A Continuum General Noise Brownian Thermostat with Applications to Film Morphology · A Multiscale, Nonlinear, Modeling Framework Enabling the Design and ...

16

Multi-Scale Modeling on Microstructures and Microstructure ...  

Science Conference Proceedings (OSTI)

Presentation Title, Multi-Scale Modeling on Microstructures and Microstructure- Property Relations of High Temperature Materials for Fossil Energy Applications.

17

International Conference on Multiscale Methods and Partial Differential Equations.  

SciTech Connect

The International Conference on Multiscale Methods and Partial Differential Equations (ICMMPDE for short) was held at IPAM, UCLA on August 26-27, 2005. The conference brought together researchers, students and practitioners with interest in the theoretical, computational and practical aspects of multiscale problems and related partial differential equations. The conference provided a forum to exchange and stimulate new ideas from different disciplines, and to formulate new challenging multiscale problems that will have impact in applications.

Thomas Hou

2006-12-12T23:59:59.000Z

18

Final Report for Integrated Multiscale Modeling of Molecular Computing Devices  

SciTech Connect

In collaboration with researchers at Vanderbilt University, North Carolina State University, Princeton and Oakridge National Laboratory we developed multiscale modeling and simulation methods capable of modeling the synthesis, assembly, and operation of molecular electronics devices. Our role in this project included the development of coarse-grained molecular and mesoscale models and simulation methods capable of simulating the assembly of millions of organic conducting molecules and other molecular components into nanowires, crossbars, and other organized patterns.

Glotzer, Sharon C.

2013-08-28T23:59:59.000Z

19

Multiscale Stochastic Simulation and Modeling  

Science Conference Proceedings (OSTI)

Acceleration driven instabilities of fluid mixing layers include the classical cases of Rayleigh-Taylor instability, driven by a steady acceleration and Richtmyer-Meshkov instability, driven by an impulsive acceleration. Our program starts with high resolution methods of numerical simulation of two (or more) distinct fluids, continues with analytic analysis of these solutions, and the derivation of averaged equations. A striking achievement has been the systematic agreement we obtained between simulation and experiment by using a high resolution numerical method and improved physical modeling, with surface tension. Our study is accompanies by analysis using stochastic modeling and averaged equations for the multiphase problem. We have quantified the error and uncertainty using statistical modeling methods.

James Glimm; Xiaolin Li

2006-01-10T23:59:59.000Z

20

Optimization Online - A stochastic multiscale model for electricity ...  

E-Print Network (OSTI)

May 30, 2011 ... A stochastic multiscale model for electricity generation capacity expansion. Panos Parpas(pparpas ***at*** mit.edu) Mort Webster(mort ***at*** ...

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


21

Modeling of Multi-Scale Phenomena in Materials Processing - III  

Science Conference Proceedings (OSTI)

Mei Li, Ford Motor Company. Scope, The purpose of the symposium is to present the development of computational techniques for the modeling of multi-scale ...

22

Moist multi-scale models for the hurricane embryo  

SciTech Connect

Determining the finite-amplitude preconditioned states in the hurricane embryo, which lead to tropical cyclogenesis, is a central issue in contemporary meteorology. In the embryo there is competition between different preconditioning mechanisms involving hydrodynamics and moist thermodynamics, which can lead to cyclogenesis. Here systematic asymptotic methods from applied mathematics are utilized to develop new simplified moist multi-scale models starting from the moist anelastic equations. Three interesting multi-scale models emerge in the analysis. The balanced mesoscale vortex (BMV) dynamics and the microscale balanced hot tower (BHT) dynamics involve simplified balanced equations without gravity waves for vertical vorticity amplification due to moist heat sources and incorporate nonlinear advective fluxes across scales. The BMV model is the central one for tropical cyclogenesis in the embryo. The moist mesoscale wave (MMW) dynamics involves simplified equations for mesoscale moisture fluctuations, as well as linear hydrostatic waves driven by heat sources from moisture and eddy flux divergences. A simplified cloud physics model for deep convection is introduced here and used to study moist axisymmetric plumes in the BHT model. A simple application in periodic geometry involving the effects of mesoscale vertical shear and moist microscale hot towers on vortex amplification is developed here to illustrate features of the coupled multi-scale models. These results illustrate the use of these models in isolating key mechanisms in the embryo in a simplified content.

Majda, Andrew J. [New York University; Xing, Yulong [ORNL; Mohammadian, Majid [University of Ottawa, Canada

2010-01-01T23:59:59.000Z

23

Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades  

E-Print Network (OSTI)

Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades PROEFSCHRIFT ter Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades / by Tiedo Tinga. ­ Eindhoven accumulation 120 5.5 Application 121 5.6 Summary and conclusions 128 6. Application to gas turbine parts 131 6

24

Multiscale finite element methods for high-contrast problems using local spectral basis functions  

Science Conference Proceedings (OSTI)

In this paper we study multiscale finite element methods (MsFEMs) using spectral multiscale basis functions that are designed for high-contrast problems. Multiscale basis functions are constructed using eigenvectors of a carefully selected local spectral ... Keywords: High contrast, Multiscale finite element, Porous media, Spectral

Yalchin Efendiev; Juan Galvis; Xiao-Hui Wu

2011-02-01T23:59:59.000Z

25

Multiscale modeling with carbon nanotubes  

Science Conference Proceedings (OSTI)

Technologically important nanomaterials come in all shapes and sizes. They can range from small molecules to complex composites and mixtures. Depending upon the spatial dimensions of the system and properties under investigation computer modeling of ... Keywords: DFT (density functional theory), Mesoscale modeling, Molecular modeling, NEGF (nonequilibrium Green's function), NEMS (nanoelectromechanical sensors), Nanocomposites, Nanotubes, Sensors

Amitesh Maiti

2008-02-01T23:59:59.000Z

26

Multiscale modeling in granular flow  

E-Print Network (OSTI)

Granular materials are common in everyday experience, but have long-resisted a complete theoretical description. Here, we consider the regime of slow, dense granular flow, for which there is no general model, representing ...

Rycroft, Christopher Harley

2007-01-01T23:59:59.000Z

27

A Multiscale Modeling System: Developments, Applications, and Critical Issues  

Science Conference Proceedings (OSTI)

A multiscale modeling framework (MMF), which replaces the conventional cloud parameterizations with a cloud-resolving model (CRM) in each grid column of a GCM, constitutes a new and promising approach for climate modeling. The MMF can provide for ...

Wei-Kuo Tao; William Lau; Joanne Simpson; Jiun-Dar Chern; Robert Atlas; David Randall; Marat Khairoutdinov; Jui-Lin Li; Duane E. Waliser; Jonathan Jiang; Arthur Hou; Xin Lin; Christa Peters-Lidard

2009-04-01T23:59:59.000Z

28

A multilevel multiscale mimetic method for an anisotropic infiltration problem  

Science Conference Proceedings (OSTI)

Modeling of multiphase flow and transport in highly heterogeneous porous media must capture a broad range of coupled spatial and temporal scales. Recently, a hierarchical approach dubbed the Multilevel Multiscale Mimetic (M3) method, was developed to simulate two-phase flow in porous media. The M{sup 3} method is locally mass conserving at all levels in its hierarchy, it supports unstructured polygonal grids and full tensor permeabilities, and it can achieve large coarsening factors. In this work we consider infiltration of water into a two-dimensional layered medium. The grid is aligned with the layers but not the coordinate axes. We demonstrate that with an efficient temporal updating strategy for the coarsening parameters, fine-scale accuracy of prominent features in the flow is maintained by the M{sup 3} method.

Lipnikov, Konstantin [Los Alamos National Laboratory; Moulton, David [Los Alamos National Laboratory; Svyatskiy, Daniil [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

29

Generalized Multiscale Finite Element Methods (GMsFEM)  

E-Print Network (OSTI)

In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be reused for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. 1

Yalchin Efendiev; Juan Galvis; Thomas Y. Hou

2013-01-01T23:59:59.000Z

30

A Bidirectional Coupling Procedure Applied to Multiscale Respiratory Modeling  

SciTech Connect

In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFD) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the Modified Newton’s Method with nonlinear Krylov accelerator developed by Carlson and Miller [1, 2, 3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD-ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural pressure applied to the multiple sets of ODEs. In both the simplified geometry and in the imaging-based geometry, the performance of the method was comparable to that of monolithic schemes, in most cases requiring only a single CFD evaluation per time step. Thus, this new accelerator allows us to begin combining pulmonary CFD models with lower-dimensional models of pulmonary mechanics with little computational overhead. Moreover, because the CFD and lower-dimensional models are totally separate, this framework affords great flexibility in terms of the type and breadth of the adopted lower-dimensional model, allowing the biomedical researcher to appropriately focus on model design. Research funded by the National Heart Lung and Blood Institute Award 1RO1HL073598.

Kuprat, Andrew P.; Kabilan, Senthil; Carson, James P.; Corley, Richard A.; Einstein, Daniel R.

2013-07-01T23:59:59.000Z

31

SPARK: a framework for multi-scale agent-based biomedical modeling  

Science Conference Proceedings (OSTI)

Multi-scale modeling of complex biological systems remains a central challenge in the systems biology community. A method of dynamic knowledge representation known as agent-based modeling enables the study of higher level behavior emerging from discrete ... Keywords: agent-based modeling, biomedical modeling

Alexey Solovyev; Maxim Mikheev; Leming Zhou; Joyeeta Dutta-Moscato; Cordelia Ziraldo; Gary An; Yoram Vodovotz; Qi Mi

2010-04-01T23:59:59.000Z

32

Multiscale Modeling and Homogenization of Composite Materials  

E-Print Network (OSTI)

where for ? = 52 we have carbon-fiber material properties.52, which gives us a carbon fiber. Figure 7.18: Fibers with52, which gives us a carbon fiber. To conduct the multiscale

Mseis, George

2010-01-01T23:59:59.000Z

33

Adaptive multiscale finite-volume method for nonlinear multiphase transport in heterogeneous formations  

Science Conference Proceedings (OSTI)

In the previous multiscale finite-volume (MSFV) method, an efficient and accurate multiscale approach was proposed to solve the elliptic flow equation. The reconstructed fine-scale velocity field was then used to solve the nonlinear hyperbolic transport ... Keywords: Adaptivity, Multigrid, Multiphase flow, Multiscale finite-volume, Nonlinear transport, Porous media, Reservoir simulation

S. H. Lee; H. Zhou; H. A. Tchelepi

2009-12-01T23:59:59.000Z

34

Automated Regularization Parameter Selection in Multi-Scale Total Variation Models for Image Restoration  

Science Conference Proceedings (OSTI)

Multi-scale total variation models for image restoration are introduced. The models utilize a spatially dependent regularization parameter in order to enhance image regions containing details while still sufficiently smoothing homogeneous features. The ... Keywords: Hierarchical decomposition, Local variance estimator, Order statistics, Primal-dual method, Semismooth Newton method, Spatially dependent regularization parameter, Total variation regularization

Yiqiu Dong; Michael Hintermüller; M. Monserrat Rincon-Camacho

2011-05-01T23:59:59.000Z

35

A stochastic multiscale framework for modeling flow through random heterogeneous porous media  

Science Conference Proceedings (OSTI)

Flow through porous media is ubiquitous, occurring from large geological scales down to the microscopic scales. Several critical engineering phenomena like contaminant spread, nuclear waste disposal and oil recovery rely on accurate analysis and prediction ... Keywords: Collocation methods, Data-driven modeling, Manifold learning, Mixed finite elements, Non-linear model reduction, Scalable algorithms, Sparse grids, Stochastic partial differential equations, Variational multiscale methods

B. Ganapathysubramanian; N. Zabaras

2009-01-01T23:59:59.000Z

36

SPARK: A Framework for Multi-Scale Agent-Based Biomedical Modeling  

Science Conference Proceedings (OSTI)

Multi-scale modeling of complex biological systems remains a central challenge in the systems biology community. A method of dynamic knowledge representation known as agent-based modeling enables the study of higher level behavior emerging from discrete ... Keywords: Agent-Based, Computer Simulation, Framework, Models, SPARK

Alexey Solovyev; Maxim Mikheev; Leming Zhou; Joyeeta Dutta-Moscato; Cordelia Ziraldo; Gary An; Yoram Vodovotz; Qi Mi

2010-07-01T23:59:59.000Z

37

Evaluation of the Operational Multiscale Environment Model with Grid Adaptivity against the European Tracer Experiment  

Science Conference Proceedings (OSTI)

The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA) is a multiscale nonhydrostatic atmospheric simulation system based on an adaptive unstructured grid. The basic philosophy behind the OMEGA development has been the creation ...

Zafer Boybeyi; Nash'at N. Ahmad; David P. Bacon; Thomas J. Dunn; Mary S. Hall; Pius C. S. Lee; R. Ananthakrishna Sarma; Tim R. Wait

2001-09-01T23:59:59.000Z

38

Multiscale finite-volume method for compressible multiphase flow in porous media  

Science Conference Proceedings (OSTI)

The Multiscale Finite-Volume (MSFV) method has been recently developed and tested for multiphase-flow problems with simplified physics (i.e. incompressible flow without gravity and capillary effects) and proved robust, accurate and efficient. However, ... Keywords: compressibility, finite-volume methods, multiphase flow in porous media, multiscale methods, reservoir simulation

Ivan Lunati; Patrick Jenny

2006-08-01T23:59:59.000Z

39

A variational multiscale finite element method for multiphase flow in porous media  

Science Conference Proceedings (OSTI)

We present a stabilized finite element method for the numerical solution of multiphase flow in porous media, based on a multiscale decomposition of pressures and fluid saturations into resolved (or grid) scales and unresolved (or subgrid) scales. The ... Keywords: Conservation laws, Finite elements, Multiphase flow, Porous media, Shocks, Stabilized methods, Variational multiscale, Waterflood

Ruben Juanes

2005-04-01T23:59:59.000Z

40

A variational multiscale finite element method for multiphase flow in porous media  

Science Conference Proceedings (OSTI)

We present a stabilized finite element method for the numerical solution of multiphase flow in porous media, based on a multiscale decomposition of pressures and fluid saturations into resolved (or grid) scales and unresolved (or subgrid) scales. The ... Keywords: conservation laws, finite elements, multiphase flow, porous media, shocks, stabilized methods, variational multiscale, waterflood

Ruben Juanes

2005-04-01T23:59:59.000Z

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


41

Multi-scale finite-volume method for elliptic problems in subsurface flow simulation  

Science Conference Proceedings (OSTI)

In this paper we present a multi-scale finite-volume (MSFV) method to solve elliptic problems with many spatial scales arising from flow in porous media. The method efficiently captures the effects of small scales on a coarse grid, is conservative, and ... Keywords: finite-volume, multi-scale physics, subsurface flow, upscaling

P. Jenny; S. H. Lee; H. A. Tchelepi

2003-05-01T23:59:59.000Z

42

Post-refinement multiscale method for pin power reconstruction  

SciTech Connect

The ability to accurately predict local pin powers in nuclear reactors is necessary to understand the mechanisms that cause fuel pin failure during steady state and transient operation. In the research presented here, methods are developed to improve the local solution using high order methods with boundary conditions from a low order global solution. Several different core configurations were tested to determine the improvement in the local pin powers compared to the standard techniques based on diffusion theory and pin power reconstruction (PPR). The post-refinement multiscale methods use the global solution to determine boundary conditions for the local solution. The local solution is solved using either a fixed boundary source or an albedo boundary condition; this solution is 'post-refinement' and thus has no impact on the global solution. (authors)

Collins, B.; Seker, V.; Downar, T. [Dept. of Nuclear Engineering and Radiological Sciences, Univ. of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48109 (United States); Xu, Y. [Argonne National Laboratory (United States)

2012-07-01T23:59:59.000Z

43

Multiscale Modeling of Irradiation effects in Fusion Materials  

DOE Green Energy (OSTI)

The aim of this collaborative research work was to apply predictive, physically based multiscale modeling to improve understanding of the underlying mechanisms of material changes in the fusion environment, with the ultimate objective to aid development of advanced materials. The multiscale modeling methodology involved a hierarchical approach, integrating ab initio electronic structure calculations, molecular dynamics (MD) simulations, kinetic Monte Carlo (KMC), and three dimensional dislocation dynamics (DD) simulations, over the relevant length and time scales to model the fates of defects and solutes (including hydrogen and helium) and thus, predict microstructural evolution in ferritic/martensitic and vanadium based alloys. The main task at WSU was to investigate changes in mechanical properties as a result of the production of a varied population of nanostructural features and to be obtained from three dimensional dislocation dynamics simulation (DD). The initial dislocation structure and microstructure could be obtained from electron microscopy characterization and the appropriate nanostructural features produced during irradiation are introduced from predictions of the multiscale modeling. The dislocation structure was then allowed to evolve under an applied load, taking into account all possible forces and reactions between the dislocations with the radiation induced nanostructure as well as network dislocations. In this manner, quantitative predictions of irradiation hardening would result without the use of empirical constants within the framework of dispersed barrier hardening models.

Hussein Zbib

2004-12-23T23:59:59.000Z

44

A Dynamically Adapting Weather and Dispersion Model: The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA)  

Science Conference Proceedings (OSTI)

The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA) and its embedded Atmospheric Dispersion Model is a new atmospheric simulation system for real-time hazard prediction, conceived out of a need to advance the state of the ...

David P. Bacon; Nash’at N. Ahmad; Zafer Boybeyi; Thomas J. Dunn; Mary S. Hall; Pius C. S. Lee; R. Ananthakrishna Sarma; Mark D. Turner; Kenneth T. Waight III; Steve H. Young; John W. Zack

2000-07-01T23:59:59.000Z

45

ANL/ALCF/ESP-13/8 Using Multi-scale Dynamic Rupture Models to  

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

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI: Thomas Jordan ESP Postdoc: Geoffrey Ely Science Overview This project uses dynamic rupture...

46

Multi-Scale Multi-Dimensional Model for Better Cell Design and Management (Presentation)  

DOE Green Energy (OSTI)

Describes NREL's R&D to develop a multi-scale model to assist in designing better, more reliable lithium-ion battery cells for advanced vehicles.

Kim, G.-H.; Smith, K.

2008-09-01T23:59:59.000Z

47

Atomistic-to-Continuum Multiscale Modeling with Long-Range Electrostatic Interactions in Ionic Solids  

E-Print Network (OSTI)

We present a multiscale atomistic-to-continuum method for ionic crystals with defects. Defects often play a central role in ionic and electronic solids, not only to limit reliability, but more importantly to enable the functionalities that make these materials of critical importance. Examples include solid electrolytes that conduct current through the motion of charged point defects, and complex oxide ferroelectrics that display multifunctionality through the motion of domain wall defects. Therefore, it is important to understand the structure of defects and their response to electrical and mechanical fields. A central hurdle, however, is that interactions in ionic solids include both short-range atomic interactions as well as long-range electrostatic interactions. Existing atomistic-to-continuum multi-scale methods, such as the Quasicontinuum method, are applicable only when the atomic interactions are short-range. In addition, empirical reductions of quantum mechanics to density functional models are unable...

Marshall, Jason

2013-01-01T23:59:59.000Z

48

Multiscale modeling for fluid transport in nanosystems.  

SciTech Connect

Atomistic-scale behavior drives performance in many micro- and nano-fluidic systems, such as mircrofludic mixers and electrical energy storage devices. Bringing this information into the traditionally continuum models used for engineering analysis has proved challenging. This work describes one such approach to address this issue by developing atomistic-to-continuum multi scale and multi physics methods to enable molecular dynamics (MD) representations of atoms to incorporated into continuum simulations. Coupling is achieved by imposing constraints based on fluxes of conserved quantities between the two regions described by one of these models. The impact of electric fields and surface charges are also critical, hence, methodologies to extend finite-element (FE) MD electric field solvers have been derived to account for these effects. Finally, the continuum description can have inconsistencies with the coarse-grained MD dynamics, so FE equations based on MD statistics were derived to facilitate the multi scale coupling. Examples are shown relevant to nanofluidic systems, such as pore flow, Couette flow, and electric double layer.

Lee, Jonathan W.; Jones, Reese E.; Mandadapu, Kranthi Kiran; Templeton, Jeremy Alan; Zimmerman, Jonathan A.

2013-09-01T23:59:59.000Z

49

Multiscale Modeling of Microstructure Deformation in Material ...  

Science Conference Proceedings (OSTI)

... a multi scale modelling approach combined with conventional material models ... Optimization of Thermal Cycle for Rails with Respect to the Wear Resistance.

50

Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion  

E-Print Network (OSTI)

NEEM MURI Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion Puneesh Puri and Vigor Yang The Pennsylvania Aluminum Particle Combustion · Aluminum oxide cap formed under the effect of surface tension · Oxidized

Yang, Vigor

51

CyberDesign & Infrastructure for Multiscale Modeling and Simulations  

Science Conference Proceedings (OSTI)

Multiscale cyber design methodology, which usually disparate entities such as material characterization, mechanical experimentation, material design, and ...

52

Multiscale modeling of nano/micro systems by a multiscale continuum field theory  

E-Print Network (OSTI)

a multiscale the- ory for nano/micro physics. Phil Mag 85:2006) Conservation laws at nano/micro scales. J Mech MaterStresses and strains at nano/micro scales. J Mech Mater

Zeng, Xiaowei; Wang, Xianqiao; Lee, James D.; Lei, Yajie

2011-01-01T23:59:59.000Z

53

Evaluation of the Multiscale Modeling Framework Using Data from the Atmospheric Radiation Measurement Program  

Science Conference Proceedings (OSTI)

In a recently developed approach to climate modeling, called the multiscale modeling framework (MMF), a two-dimensional cloud-resolving model (CRM) is embedded into each grid column of the Community Atmospheric Model (CAM), replacing traditional ...

Mikhail Ovtchinnikov; Thomas Ackerman; Roger Marchand; Marat Khairoutdinov

2006-05-01T23:59:59.000Z

54

Multiscale Modeling of Polycrystalline Magnetostrictive Alloy Galfenol  

Science Conference Proceedings (OSTI)

First Principles Modeling of Shape Memory Alloy Magnetic Refrigeration Materials ... Different Generations of Gamma Prime Precipitates in a Commercial Nickel ...

55

Wavelet-Based Nonlinear Multiscale Decomposition Model for Electricity Load Forecasting  

E-Print Network (OSTI)

ABSTRACT: We propose a wavelet multiscale decomposition based autoregressive approach for the prediction of one-hour ahead ahead load based on historical electricity load data. This approach is based on a multiple resolution decomposition of the signal using the non-decimated or redundant Haar à trous wavelet transform whose advantage is taking into account the asymmetric nature of the time-varying data. There is an additional computational advantage in that there is no need to recompute the wavelet transform (wavelet coefficients) of the full signal if the electricity data (time series) is regularly updated. We assess results produced by this multiscale autoregressive (MAR) method, in both linear and non-linear variants, with single resolution autoregression (AR), multilayer perceptron (MLP), Elman recurrent neural network (ERN) and the general regression neural network (GRNN) models. Results are based on the New South Wales (Australia) electricity load data that is provided by the National Electricity Market

D. Benaouda; F. Murtagh; J. L. Starck; O. Renaud; Universiti Tenaga Nasional; Jalan Kajang-puchong

2005-01-01T23:59:59.000Z

56

Multiscale/Multiphysics Modeling of Biomass Thermochemical Processes  

SciTech Connect

Computational problems in simulating biomass thermochemical processes involve coupling processes that span several orders of magnitude in space and time. Computational difficulties arise from the multitude of the problem governing equations, each typically applying over a narrow range of spatiotemporal scales, thus making it necessary to represent the processes as the result of the interaction of multiple physics modules, termed here as multiscale/multiphysics (MSMP) coupling. Predictive simulations for such processes require algorithms that can efficiently integrate the underlying MSMP methods across the scales in order to achieve prescribed accuracy and control the computational cost. In addition, MSMP algorithms must scale to one hundred thousand processors or more in order to effectively harness the new computational resources and accelerate the scientific advances. In this chapter, we discuss the state-of-the-art in modeling the macro-scale phenomena in a biomass pyrolysis reactor along with details of the shortcomings and prospects in improving predictability. We also introduce the various multiphysics modules needed to model thermochemical conversion at lower spatiotemporal scales. Furthermore, we illustrate the need for MSMP coupling for thermochemical processes in biomass and provide an overview of the wavelet-based coupling techniques we have developed recently. In particular, we provide details about the compound wavelet matrix (CWM) and the dynamic CWM (dCWM) methods and show they are highly efficient in transferring information among multiphysics models across multiple temporal and spatial scales. The algorithmic gain is in addition to the parallel spatial scalability from traditional domain decomposition methods. The CWM algorithms are serial in time and limited by the smallest-system time-scales. In order to relax this algorithmic constraint, we have recently coupled time parallel (TP) algorithms to CWM, thus yielding a novel approach termed tpCWM. We present preliminary results from the tpCWM technique, indicating that we can accelerate time-to-solution by 2 to 3-orders of magnitude even on 20-processors and this can potentially constitute a new paradigm for MSMP simulations. If such improvements in simulation capability can be generalized, the tpCWM approach can lead the way to predictive simulations of biomass thermochemical processes.

Pannala, Sreekanth [ORNL; Simunovic, Srdjan [ORNL; Frantziskonis, G. [University of Arizona

2010-01-01T23:59:59.000Z

57

A Multiscale Anelastic Model for Meteorological Research  

Science Conference Proceedings (OSTI)

The recently reported nonhydrostatic anelastic numerical model for simulating a range of atmospheric processes on scales from micro to planetary is extended to moist processes. A theoretical formulation of moist precipitating thermodynamics ...

Wojciech W. Grabowski; Piotr K. Smolarkiewicz

2002-04-01T23:59:59.000Z

58

Evaluation of Northern Hemisphere Blocking Climatology in the Global Environment Multiscale Model  

Science Conference Proceedings (OSTI)

The performance of the Global Environmental Multiscale (GEM) model, the Canadian operational numerical model, in reproducing atmospheric low-frequency variability is evaluated in the context of Northern Hemisphere blocking climatology. The ...

Etienne Dunn-Sigouin; Seok-Woo Son; Hai Lin

2013-02-01T23:59:59.000Z

59

Modulation of Internal Gravity Waves in a Multiscale Model for Deep Convection on Mesoscales  

Science Conference Proceedings (OSTI)

Starting from the conservation laws for mass, momentum, and energy together with a three-species bulk microphysics model, a model for the interaction of internal gravity waves and deep convective hot towers is derived using multiscale asymptotic ...

Daniel Ruprecht; Rupert Klein; Andrew J. Majda

2010-08-01T23:59:59.000Z

60

Final technical report for DOE Computational Nanoscience Project: Integrated Multiscale Modeling of Molecular Computing Devices  

Science Conference Proceedings (OSTI)

This document reports the outcomes of the Computational Nanoscience Project, "Integrated Multiscale Modeling of Molecular Computing Devices". It includes a list of participants and publications arising from the research supported.

Cummings, P. T.

2010-02-08T23:59:59.000Z

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


61

TWO POSTDOC POSITIONS IN MULTISCALE MODELLING OF RELIABILITY OF NEW GENERATION NANO-DEVICES  

E-Print Network (OSTI)

TWO POSTDOC POSITIONS IN MULTISCALE MODELLING OF RELIABILITY OF NEW GENERATION NANO-DEVICES Two nano-devices. These posts are part of an international MORDRED project funded by EU FP7 to develop new

Saunders, Mark

62

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion...  

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

Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI Name: Thomas Jordan PI Email: tjordan@usc.edu Institution: USC Allocation Program: ESP Allocation Hours at...

63

A computational method to extract macroscopic variables and their dynamics in multiscale systems  

E-Print Network (OSTI)

A systematic method to identify and extract the slow variables from a high-dimensional complex multiscale system is developed. The slow subspace is unravelled by employing the transfer operator and the Koopman operator the eigenfunctions of which are used to define a projection onto a slow subspace. The full system is then reformulated in terms of those slow variables, and we present and effective multiscale integrator, which allows for a large macro time step to propagate forward the slow variables. We illustrate our method with several examples and show how the reduced slow dynamics faithfully represents statistical features of the full dynamics which are not coordinate dependent.

Gary Froyland; Georg A. Gottwald; Andy Hammerlindl

2013-10-30T23:59:59.000Z

64

Multiscale/Multiphysics Methods Used in Heterogeneous Chemically Reacting Flows  

Science Conference Proceedings (OSTI)

This talk will provide an overview of modeling multiphase chemical reactors and the various methods currently used which span ¿10 orders of magnitude in both temporal and spatial scales. This includes a wide-variety of models like DFT, Lattice Boltzmann methods, Discrete particle simulations, CFD and process models. This presentation will also address the obstacles that need to be addressed to improve the integration across the scales and predictability of the overall device scale simulations.

O'Brien, T.J.

2007-02-01T23:59:59.000Z

65

Adaptive fully implicit multi-scale finite-volume method for multi-phase flow and transport in heterogeneous porous media  

Science Conference Proceedings (OSTI)

We describe a sequential fully implicit (SFI) multi-scale finite volume (MSFV) algorithm for nonlinear multi-phase flow and transport in heterogeneous porous media. The method extends the recently developed multiscale approach, which is based on an IMPES ... Keywords: coupled flow and transport, finite-volume, heterogeneous porous media, immiscible multi-phase flow, multiscale methods, numerical simulation

P. Jenny; S. H. Lee; H. A. Tchelepi

2006-09-01T23:59:59.000Z

66

A locally conservative variational multiscale method for the simulation of porous media flow with multiscale source terms  

E-Print Network (OSTI)

Multiscale phenomena are ubiquitous to flow and transport in porous media. They manifest themselves through at least the following three facets: (1) effective parameters in the governing equations are scale dependent; (2) ...

Dub, Francois-Xavier

2008-01-01T23:59:59.000Z

67

Choose inter-element coupling to preserve self-adjoint dynamics in multiscale modelling and computation  

Science Conference Proceedings (OSTI)

Consider the macroscale modelling of microscale spatio-temporal dynamics. Here we develop an approach to ensure coarse scale discrete models preserve important self-adjoint properties of the microscale dynamics. The first part explores the discrete modelling ... Keywords: Centre manifold theory, Closure, Macroscale discretisation, Multiscale modelling

A. J. Roberts

2010-10-01T23:59:59.000Z

68

Multiscale Geometric Methods for Data Sets I: Multiscale SVD, Noise and Curvature  

E-Print Network (OSTI)

Large data sets are often modeled as being noisy samples from probability distributions in R^D, with D large. It has been noticed that oftentimes the support M of these probability distributions seems to be well-approximated ...

Little, Anna V.

2012-09-08T23:59:59.000Z

69

Bayesian data assimilation for stochastic multiscale models of transport in porous media.  

SciTech Connect

We investigate Bayesian techniques that can be used to reconstruct field variables from partial observations. In particular, we target fields that exhibit spatial structures with a large spectrum of lengthscales. Contemporary methods typically describe the field on a grid and estimate structures which can be resolved by it. In contrast, we address the reconstruction of grid-resolved structures as well as estimation of statistical summaries of subgrid structures, which are smaller than the grid resolution. We perform this in two different ways (a) via a physical (phenomenological), parameterized subgrid model that summarizes the impact of the unresolved scales at the coarse level and (b) via multiscale finite elements, where specially designed prolongation and restriction operators establish the interscale link between the same problem defined on a coarse and fine mesh. The estimation problem is posed as a Bayesian inverse problem. Dimensionality reduction is performed by projecting the field to be inferred on a suitable orthogonal basis set, viz. the Karhunen-Loeve expansion of a multiGaussian. We first demonstrate our techniques on the reconstruction of a binary medium consisting of a matrix with embedded inclusions, which are too small to be grid-resolved. The reconstruction is performed using an adaptive Markov chain Monte Carlo method. We find that the posterior distributions of the inferred parameters are approximately Gaussian. We exploit this finding to reconstruct a permeability field with long, but narrow embedded fractures (which are too fine to be grid-resolved) using scalable ensemble Kalman filters; this also allows us to address larger grids. Ensemble Kalman filtering is then used to estimate the values of hydraulic conductivity and specific yield in a model of the High Plains Aquifer in Kansas. Strong conditioning of the spatial structure of the parameters and the non-linear aspects of the water table aquifer create difficulty for the ensemble Kalman filter. We conclude with a demonstration of the use of multiscale stochastic finite elements to reconstruct permeability fields. This method, though computationally intensive, is general and can be used for multiscale inference in cases where a subgrid model cannot be constructed.

Marzouk, Youssef M. (Massachusetts Institute of Technology, Cambridge, MA); van Bloemen Waanders, Bart Gustaaf (Sandia National Laboratories, Albuquerque NM); Parno, Matthew (Massachusetts Institute of Technology, Cambridge, MA); Ray, Jaideep; Lefantzi, Sophia; Salazar, Luke (Sandia National Laboratories, Albuquerque NM); McKenna, Sean Andrew (Sandia National Laboratories, Albuquerque NM); Klise, Katherine A. (Sandia National Laboratories, Albuquerque NM)

2011-10-01T23:59:59.000Z

70

Collaborating for Multi-Scale Chemical Science  

SciTech Connect

Advanced model reduction methods were developed and integrated into the CMCS multiscale chemical science simulation software. The new technologies were used to simulate HCCI engines and burner flames with exceptional fidelity.

William H. Green

2006-07-14T23:59:59.000Z

71

Integration of regional to outcrop digital data: 3D visualisation of multi-scale geological models  

Science Conference Proceedings (OSTI)

Multi-scale geological models contain three-dimensional, spatially referenced data, typically spanning at least six orders of magnitude from outcrop to regional scale. A large number of different geological and geophysical data sources can be combined ... Keywords: Digital geological mapping, Immersive visualisation, Terrestrial laser-scanning, User interaction, Virtual outcrop models

R. R. Jones; K. J. W. McCaffrey; P. Clegg; R. W. Wilson; N. S. Holliman; R. E. Holdsworth; J. Imber; S. Waggott

2009-01-01T23:59:59.000Z

72

Large eddy simulation models for incompressible magnetohydrodynamics derived from the variational multiscale formulation  

Science Conference Proceedings (OSTI)

Novel large eddy simulation (LES) models are developed for incompressible magnetohydrodynamics (MHD). These models include the application of the variational multiscale formulation of LES to the equations of incompressible MHD. Additionally, a new residual-based eddy viscosity model is introduced for MHD. A mixed LES model that combines the strengths of both of these models is also derived. The new models result in a consistent numerical method that is relatively simple to implement. The need for a dynamic procedure in determining model coefficients is no longer required. The new LES models are tested on a decaying Taylor-Green vortex generalized to MHD and benchmarked against classical LES turbulence models. The LES simulations are run in a periodic box of size [-{pi}, {pi}]{sup 3} with 32 modes in each direction and are compared to a direct numerical simulation (DNS) with 512 modes in each direction. The new models are able to account for the essential MHD physics which is demonstrated via comparisons of energy spectra. We also compare the performance of our models to a DNS simulation by Pouquet et al.['The dynamics of unforced turbulence at high Reynolds number for Taylor-Green vortices generalized to MHD,' Geophys. Astrophys. Fluid Dyn. 104, 115-134 (2010)], for which the ratio of DNS modes to LES modes is 262:144.

Sondak, David; Oberai, Assad A. [Rensselaer Polytechnic Institute, SCOREC, CII 4225, 110 8th Street, Troy, New York 12180 (United States)

2012-10-15T23:59:59.000Z

73

Finite element analysis of grain-matrix micro-cracking in shale within the context of a multiscale modeling  

E-Print Network (OSTI)

, hydrofracturing, or oil shale production. Current macro- scale and multiscale models do not account simultaneouslyFinite element analysis of grain-matrix micro-cracking in shale within the context of a multiscale-cracking in shale at grain-matrix inter- faces, assuming constituents are composed of quart silt grains

Regueiro, Richard A.

74

Evaluation of the Simulated Interannual and Subseasonal Variability in an AMIP-Style Simulation Using the CSU Multiscale Modeling Framework  

Science Conference Proceedings (OSTI)

The Colorado State University (CSU) Multiscale Modeling Framework (MMF) is a new type of general circulation model (GCM) that replaces the conventional parameterizations of convection, clouds, and boundary layer with a cloud-resolving model (CRM) ...

Marat Khairoutdinov; Charlotte DeMott; David Randall

2008-02-01T23:59:59.000Z

75

A second gradient theoretical framework for hierarchical multiscale modeling of materials  

SciTech Connect

A theoretical framework for the hierarchical multiscale modeling of inelastic response of heterogeneous materials has been presented. Within this multiscale framework, the second gradient is used as a non local kinematic link between the response of a material point at the coarse scale and the response of a neighborhood of material points at the fine scale. Kinematic consistency between these scales results in specific requirements for constraints on the fluctuation field. The wryness tensor serves as a second-order measure of strain. The nature of the second-order strain induces anti-symmetry in the first order stress at the coarse scale. The multiscale ISV constitutive theory is couched in the coarse scale intermediate configuration, from which an important new concept in scale transitions emerges, namely scale invariance of dissipation. Finally, a strategy for developing meaningful kinematic ISVs and the proper free energy functions and evolution kinetics is presented.

Luscher, Darby J [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Mc Dowell, David L [GEORGIA TECH

2009-01-01T23:59:59.000Z

76

Multi-scale modeling and experimental investigations of geopolymeric gels at elevated temperatures  

Science Conference Proceedings (OSTI)

Geopolymers are an emerging class of cementitious binders formed by aluminum-silica rich activating materials. Experimental results indicate that geopolymer concrete is relatively stable at elevated temperatures, and could be possibly utilized in applications ... Keywords: Geopolymer concrete, High temperature applications, Microstructure characterization, Multi-scale modeling

Kunal Kupwade-Patil, Fernando Soto, Ancy Kunjumon, Erez N. Allouche, Daniela S. Mainardi

2013-06-01T23:59:59.000Z

77

Multiscale modeling and distributed computing to predict cosmesis outcome after a lumpectomy  

Science Conference Proceedings (OSTI)

Surgery for early stage breast carcinoma is either total mastectomy (complete breast removal) or surgical lumpectomy (only tumor removal). The lumpectomy or partial mastectomy is intended to preserve a breast that satisfies the woman's cosmetic, emotional ... Keywords: Breast cancer, Cellular automata, Distributed computing, Multiscale model

M. Garbey, R. Salmon, D. Thanoon, B. L. Bass

2013-07-01T23:59:59.000Z

78

Multiscale and Multiphysic Models in CFD Modeling and Simulation ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

79

Multi-scale plasma simulation by the interlocking of magnetohydrodynamic model and particle-in-cell kinetic model  

Science Conference Proceedings (OSTI)

Many kinds of simulation models have been developed to understand the complex plasma systems. However, these simulation models have been separately performed because the fundamental assumption of each model is different and restricts the physical processes ... Keywords: Interlocked simulation, MHD, Multi-scale, PIC, Plasma

Tooru Sugiyama; Kanya Kusano

2007-12-01T23:59:59.000Z

80

A Multiscale Ensemble Filtering System for Hydrologic Data Assimilation. Part II: Application to Land Surface Modeling with Satellite Rainfall Forcing  

Science Conference Proceedings (OSTI)

Part I of this series of studies developed procedures to implement the multiscale filtering algorithm for land surface hydrology and performed assimilation experiments with rainfall ensembles from a climate model. However, a most important ...

Ming Pan; Eric F. Wood

2009-12-01T23:59:59.000Z

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


81

Multiscale Convective Wave Disturbances in the Tropics: Insights from a Two-Dimensional Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

Multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating, two-dimensional cloud model forced by uniform cooling. To articulate the dynamics of these ...

Stefan N. Tulich; Brian E. Mapes

2008-01-01T23:59:59.000Z

82

Multi-Scale Multi-physics Methods Development for the Calculation of Hot-Spots in the NGNP  

Science Conference Proceedings (OSTI)

Radioactive gaseous fission products are released out of the fuel element at a significantly higher rate when the fuel temperature exceeds 1600°C in high-temperature gas-cooled reactors (HTGRs). Therefore, it is of paramount importance to accurately predict the peak fuel temperature during all operational and design-basis accident conditions. The current methods used to predict the peak fuel temperature in HTGRs, such as the Next-Generation Nuclear Plant (NGNP), estimate the average fuel temperature in a computational mesh modeling hundreds of fuel pebbles or a fuel assembly in a pebble-bed reactor (PBR) or prismatic block type reactor (PMR), respectively. Experiments conducted in operating HTGRs indicate considerable uncertainty in the current methods and correlations used to predict actual temperatures. The objective of this project is to improve the accuracy in the prediction of local "hot" spots by developing multi-scale, multi- physics methods and implementing them within the framework of established codes used for NGNP analysis. The multi-scale approach which this project will implement begins with defining suitable scales for a physical and mathematical model and then deriving and applying the appropriate boundary conditions between scales. The macro scale is the greatest length that describes the entire reactor, whereas the meso scale models only a fuel block in a prismatic reactor and ten to hundreds of pebbles in a pebble bed reactor. The smallest scale is the micro scale--the level of a fuel kernel of the pebble in a PBR and fuel compact in a PMR--which needs to be resolved in order to calculate the peak temperature in a fuel kernel.

Downar, Thomas; Seker, Volkan

2013-04-30T23:59:59.000Z

83

Multiscale Reservoir Simulation: Layer Design, Full Field Pseudoization and Near Well Modeling  

E-Print Network (OSTI)

In the past decades, considerable effort has been put into developing high resolution geological models for oil and gas reservoirs. Although the growth of computational power is rapid, the static model size still exceeds the model size for routine reservoir simulation. We develop and apply a variety of grid coarsening and refinement algorithms and single and multiphase upscaling approaches, applied to tight gas and conventional reservoir models. The proposed research is organized into three areas. First the upgridding of detailed three dimensional geologic models is studied. We propose an improved layer design algorithm with considerations of accuracy and efficiency. This involves developing measures of reservoir heterogeneity and using these measures to design an optimal grouping of geologic model layers for flow simulation. The optimal design is shown to be a tradeoff between the desire to preserve the reservoir heterogeneity and a desire to minimize the simulation time. The statistical analysis is validated by comparison with flow simulation results. Accurate upgridding/upscaling of single-phase parameters is necessary. However, it does not always satisfy the accuracy requirements, especially for the model which is aggressively coarsened. We introduce a pseudoization method with total mobility and effective fractional flow as the major targets. This pseudoization method helps to push upgridding/coarsening degree to the limit but still be able to reproduce the fine scale field performance. In practice, it is common to not use a different set of pseudos for every coarse cell; only a limited number of pseudo functions should be generated for different “rock types” or geological zones. For similar well patterns and well control conditions, applying pseudo is able to reproduce the fine scale performance for different simulation runs. This is the second proposed research area. Finally, it is necessary to increase flow resolution for precise field history matching and forecasting. This has received increasing attention, especially when studying hydraulically fractured wells in unconventional reservoirs. We propose a multiscale reservoir simulation model combining local grid refinement (LGR) and pillar-based upscaling for tight gas reservoir performance prediction. Pillar-based coarsening away from the wells is designed for tight gas reservoirs. It compensates for the extra computational cost from LGR, which is used to represent hydraulic fractures. Overall reservoir performances, including the accuracy and efficiency, are evaluated.

Du, Song

2012-12-01T23:59:59.000Z

84

Relational Grounding Facilitates Development of Scientifically Useful Multiscale Models  

E-Print Network (OSTI)

Cellular automata, agent-based models h (ABM), and actornodes (LN-ODE), and an agent-based model (ABM) of granulomathat, in effect, the agent-based model depends intricately

Hunt, C Anthony; Ropella, Glen EP; Lam, Tai; Gewitz, Andrew D

2011-01-01T23:59:59.000Z

85

A comparison of staggered solution schemes for coupled particle---continuum systems modeled with the Arlequin method  

Science Conference Proceedings (OSTI)

This contribution aims at a systematic investigation of staggered solution schemes for the computation of coupled domains having different resolutions in space, a problem frequently arising in multi-scale modeling of materials. To couple a standard finite ... Keywords: Atomistic---continuum coupling, Bridging domain method, Domain decomposition, Lagrange multipliers, Multiscale modeling

S. Pfaller; G. Possart; P. Steinmann; M. Rahimi; F. Müller-Plathe; M. C. Böhm

2012-05-01T23:59:59.000Z

86

Multi-Scale Modeling of Irradiation Effects on Nuclear Fuel ...  

Science Conference Proceedings (OSTI)

Ab Initio-Based Rate Theory Modeling of Radiation Induced Segregation in ... Benchmarking of Structural Materials Pre-Selected for Advanced Nuclear Reactors.

87

Multi-scale Modeling of Microstructure Deformation in Material ...  

Science Conference Proceedings (OSTI)

Modeling Metal Powder Compaction Using Combined Finite and Discrete .... Optimization of Thermal Cycle for Rails with Respect to the Wear Resistance: ...

88

Multiscale Modeling of Ingot Solidification Structure Controlled by ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

89

Toward a Multiscale Approach for Computational Atmospheric Modeling  

Science Conference Proceedings (OSTI)

Atmospheric motions are generally characterized by a wide range of multiple length and time scales, and a numerical method must use a fine grid to resolve such a wide range of scales. Furthermore, a very fine grid requires an extremely small time ...

Jahrul M. Alam

2011-12-01T23:59:59.000Z

90

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates  

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

Earthquake simulations help scientists understand the hazards posed by Earthquake simulations help scientists understand the hazards posed by future earthquakes. Earthquake computational models are validated by simulating well-recorded historical earthquakes and comparing simulation results to observational data. The purple border shows the extent of the 3-D structural model in the 3-D inversion. Events in red, with stations in blue. En-Jui Lee, University of Wyoming Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI Name: Thomas Jordan PI Email: tjordan@usc.edu Institution: USC Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Earth Science Researchers will use Southern California Earthquake Center (SCEC) dynamic rupture simulation software to investigate high-frequency seismic energy

91

Multiscale Multiphysics Lithium-Ion Battery Model with Multidomain Modular Framework  

Science Conference Proceedings (OSTI)

Lithium-ion batteries (LIBs) powering recent wave of personal ubiquitous electronics are also believed to be a key enabler of electrification of vehicle powertrain on the path toward sustainable transportation future. Over the past several years, National Renewable Energy Laboratory (NREL) has developed the Multi-Scale Multi-Domain (MSMD) model framework, which is an expandable platform and a generic modularized flexible framework resolving interactions among multiple physics occurring in varied length and time scales in LIB[1]. NREL has continued to enhance the functionality of the framework and to develop constituent models in the context of the MSMD framework responding to U.S. Department of Energy's CAEBAT program objectives. This talk will introduce recent advancements in NREL's LIB modeling research in regards of scale-bridging, multi-physics integration, and numerical scheme developments.

Kim, G. H.

2013-01-01T23:59:59.000Z

92

Overview of Computer-Aided Engineering of Batteries and Introduction to Multi-Scale, Multi-Dimensional Modeling of Li-Ion Batteries (Presentation)  

DOE Green Energy (OSTI)

This 2012 Annual Merit Review presentation gives an overview of the Computer-Aided Engineering of Batteries (CAEBAT) project and introduces the Multi-Scale, Multi-Dimensional model for modeling lithium-ion batteries for electric vehicles.

Pesaran, A.; Kim, G. H.; Smith, K.; Santhanagopalan, S.; Lee, K. J.

2012-05-01T23:59:59.000Z

93

Validation and Calibration of Nuclear Thermal Hydraulics Multiscale Multiphysics Models - Subcooled Flow Boiling Study  

SciTech Connect

In addition to validation data plan, development of advanced techniques for calibration and validation of complex multiscale, multiphysics nuclear reactor simulation codes are a main objective of the CASL VUQ plan. Advanced modeling of LWR systems normally involves a range of physico-chemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which occur over a wide range of spatial and temporal scales. To a large extent, the accuracy of (and uncertainty in) overall model predictions is determined by the correctness of various sub-models, which are not conservation-laws based, but empirically derived from measurement data. Such sub-models normally require extensive calibration before the models can be applied to analysis of real reactor problems. This work demonstrates a case study of calibration of a common model of subcooled flow boiling, which is an important multiscale, multiphysics phenomenon in LWR thermal hydraulics. The calibration process is based on a new strategy of model-data integration, in which, all sub-models are simultaneously analyzed and calibrated using multiple sets of data of different types. Specifically, both data on large-scale distributions of void fraction and fluid temperature and data on small-scale physics of wall evaporation were simultaneously used in this work’s calibration. In a departure from traditional (or common-sense) practice of tuning/calibrating complex models, a modern calibration technique based on statistical modeling and Bayesian inference was employed, which allowed simultaneous calibration of multiple sub-models (and related parameters) using different datasets. Quality of data (relevancy, scalability, and uncertainty) could be taken into consideration in the calibration process. This work presents a step forward in the development and realization of the “CIPS Validation Data Plan” at the Consortium for Advanced Simulation of LWRs to enable quantitative assessment of the CASL modeling of Crud-Induced Power Shift (CIPS) phenomenon, in particular, and the CASL advanced predictive capabilities, in general. This report is prepared for the Department of Energy’s Consortium for Advanced Simulation of LWRs program’s VUQ Focus Area.

Anh Bui; Nam Dinh; Brian Williams

2013-09-01T23:59:59.000Z

94

The decay of multiscale signals deterministic model of the Burgers turbulence  

E-Print Network (OSTI)

This work is devoted to the study of the decay of multiscale deterministicsolutions of the unforced Burgers' equation in the limit of vanishingviscosity. A deterministic model of turbulence-like evolution is considered. We con-struct the initial perturbation as a piecewise linear analog of the Weierstrassfunction. The wavenumbers of this function form a "Weierstrass spectrum", whichaccumulates at the origin in geometric progression."Reverse" sawtooth functionswith negative initial slope are used in this series as basic functions, whiletheir amplitudes are chosen by the condition that the distribution of energyover exponential intervals of wavenumbers is the same as for the continuousspectrum in Burgers turbulence. Combining these two ideas allows us to obtainan exact analytical solution for the velocity field. We also notice that suchmultiscale waves may be constructed for multidimensional Burgers' equation. This solution has scaling exponent h=-(1+n)/2 and its evolution in time isself-similar with logarithmi...

Gurbatov, S N

2000-01-01T23:59:59.000Z

95

Multiscale Modeling of Grain Boundary Segregation and Embrittlement in Tungsten for Mechanistic Design of Alloys for Coal Fired Plants  

SciTech Connect

Based on a recent discovery of premelting-like grain boundary segregation in refractory metals occurring at high temperatures and/or high alloying levels, this project investigated grain boundary segregation and embrittlement in tungsten (W) based alloys. Specifically, new interfacial thermodynamic models have been developed and quantified to predict high-temperature grain boundary segregation in the W-Ni binary alloy and W-Ni-Fe, W-Ni-Ti, W-Ni-Co, W-Ni-Cr, W-Ni-Zr and W-Ni-Nb ternary alloys. The thermodynamic modeling results have been experimentally validated for selected systems. Furthermore, multiscale modeling has been conducted at continuum, atomistic and quantum-mechanical levels to link grain boundary segregation with embrittlement. In summary, this 3-year project has successfully developed a theoretical framework in combination with a multiscale modeling strategy for predicting grain boundary segregation and embrittlement in W based alloys.

Luo, Jian; Tomar, Vikas; Zhou, Naixie; Lee, Hongsuk

2013-06-30T23:59:59.000Z

96

Introducing a Partitioning Mechanism for PAHs into the Community Multiscale Air Quality Modeling System and Its Application to Simulating the Transport of Benzo(a)pyrene over Europe  

Science Conference Proceedings (OSTI)

Into the Community Multiscale Air Quality modeling system (CMAQ) that is widely used for simulating the transport and fate of air pollutants, a new module was inserted that accounts for the partitioning of semivolatile organic compounds—in ...

Armin Aulinger; Volker Matthias; Markus Quante

2007-11-01T23:59:59.000Z

97

Dynamically Consistent Formulations in Meteorological and Air Quality Models for Multiscale Atmospheric Studies. Part I: Governing Equations in a Generalized Coordinate System  

Science Conference Proceedings (OSTI)

In recent years, the popularity of the fully compressible nonhydrostatic atmospheric models has increased due to the need for simulating multiscale dynamics from convective to synoptic weather phenomena. These recent advances in meteorological ...

Daewon W. Byun

1999-11-01T23:59:59.000Z

98

Quantifying prediction fidelity in multiscale multiphysics simulations.  

SciTech Connect

Multiscale multiphysics problems arise in a host of application areas of significant relevance to DOE, including electrical storage systems (membranes and electrodes in fuel cells, batteries, and ultracapacitors), water surety, chemical analysis and detection systems, and surface catalysis. Multiscale methods aim to provide detailed physical insight into these complex systems by incorporating coupled effects of relevant phenomena on all scales. However, many sources of uncertainty and modeling inaccuracies hamper the predictive fidelity of multiscale multiphysics simulations. These include parametric and model uncertainties in the models on all scales, and errors associated with coupling, or information transfer, across scales/physics. This presentation introduces our work on the development of uncertainty quantification methods for spatially decomposed atomistic-to-continuum (A2C) multiscale simulations. The key thrusts of this research effort are: inference of uncertain parameters or observables from experimental or simulation data; propagation of uncertainty through particle models; propagation of uncertainty through continuum models; propagation of information and uncertainty across model/scale interfaces; and numerical and computational analysis and control. To enable the bidirectional coupling between the atomistic and continuum simulations, a general formulation has been developed for the characterization of sampling noise due to intrinsic variability in particle simulations, and for the propagation of both this sampling noise and parametric uncertainties through coupled A2C multiscale simulations. Simplified tests of noise quantification in particle computations are conducted through Bayesian inference of diffusion rates in an idealized isothermal binary material system. A proof of concept is finally presented based on application of the present formulation to the propagation of uncertainties in a model plane Couette flow, where the near wall region is handled with molecular dynamics while the bulk region is handled with continuum methods.

Adalsteinsson, Helgi

2010-04-01T23:59:59.000Z

99

A Multiscale Model for Coupled Heat Conduction and Deformations of Viscoelastic Composites  

E-Print Network (OSTI)

This study introduces a multiscale model for analyzing nonlinear thermo-viscoelastic responses of particulate composites. A simplified micromechanical model consisting of four sub-cells, i.e., one particle and three matrix sub-cells is formulated to obtain the effective thermal and mechanical properties and time-dependent response of the composites. The particle and matrix constituents are made of isotropic homogeneous viscoelastic bodies undergoing small deformation gradients. Perfect bonds are assumed along the sub-cell???s interfaces. The coupling between the thermal and mechanical response is attributed to the dissipation of energy due to the viscoelastic deformation and temperature dependent material parameters in the viscoelastic constitutive model. The micromechanical relations are formulated in terms of incremental average field quantities, i.e., stress, strain, heat flux and temperature gradient, in the sub-cells. The effective mechanical properties and coefficient of thermal expansion are derived by satisfying displacement- and traction continuities at the interfaces during the thermo-viscoelastic deformations. The effective thermal conductivity is formulated by imposing heat flux- and temperature continuities at the subcells??? interfaces. The expression of the effective specific heat at a constant stress is also established. A time integration algorithm for simultaneously solving the equations that govern heat conduction and thermoviscoelastic deformations of isotropic materials is developed. The algorithm is then incorporated within each sub-cell of the micromechanical model together with the macroscopic energy equation to determine the effective coupled thermoviscoelastic response of the particulate composite. The numerical formulation is implemented within the ABAQUS, general purpose displacement based FE software, allowing for analyzing coupled heat conduction and deformations of composite structures. Experimental data on the effective thermal properties and time dependent responses of particulate composites available in the literature are used to verify the micromechanical model formulation. The multiscale model capability is also examined by comparing the field variables, i.e., temperature, displacement, stresses and strains, obtained from heterogeneous and homogeneous composite structures, during the transient heat conduction and deformations. Examples of coupled thermoviscoelastic analyses of particulate composites and functionally graded structures are also presented. The present micromechanical modeling approach is found to be computationally efficient and shows good agreement with experiments in predicting the effective thermo-mechanical response of particulate composites and functionally graded materials. Our analyses forecast a better design for creep resistant and less dissipative structures using particulate composites and functionally graded materials.

Khan, Kamran Ahmed

2011-05-01T23:59:59.000Z

100

Time-parallel multiscale/multiphysics framework  

Science Conference Proceedings (OSTI)

We introduce the time-parallel compound wavelet matrix method (tpCWM) for modeling the temporal evolution of multiscale and multiphysics systems. The method couples time parallel (TP) and CWM methods operating at different spatial and temporal scales. ... Keywords: 02.00.00, 02.10.Jf, 05.10.-a, 46.15.-x, 47.70.Fw, Parallel-in-time, Wavelet-based multiscaling

G. Frantziskonis; K. Muralidharan; P. Deymier; S. Simunovic; P. Nukala; S. Pannala

2009-11-01T23:59:59.000Z

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


101

Multiscale simulations of blood-flow: from a platelet to an artery  

Science Conference Proceedings (OSTI)

We review our recent advances on multiscale modeling of blood flow including blood rheology. We focus on the objectives, methods, computational complexity and overall methodology for simulations at the level of glycocalyx (visualization, parallel computing, task parallelism

Leopold Grinberg; Mingge Deng; Huan Lei; Joseph A. Insley; George Em Karniadakis

2012-07-01T23:59:59.000Z

102

A Multiscale Ensemble Filtering System for Hydrologic Data Assimilation. Part I: Implementation and Synthetic Experiment  

Science Conference Proceedings (OSTI)

The multiscale autoregressive (MAR) framework was introduced in the last decade to process signals that exhibit multiscale features. It provides the method for identifying the multiscale structure in signals and a filtering procedure, and thus is ...

Ming Pan; Eric F. Wood; Dennis B. McLaughlin; Dara Entekhabi; Lifeng Luo

2009-06-01T23:59:59.000Z

103

A Multiscale Ensemble Filtering System for Hydrologic Data Assimilation. Part I: Implementation and Synthetic Experiment  

E-Print Network (OSTI)

The multiscale autoregressive (MAR) framework was introduced in the last decade to process signals that exhibit multiscale features. It provides the method for identifying the multiscale structure in signals and a filtering ...

McLaughlin, Dennis

104

A Multiscale Model for the Modulation and Rectification of the ITCZ  

Science Conference Proceedings (OSTI)

The authors introduce the modulation of the ITCZ equations (M-ITCZ), which describes the multiscale dynamics of the ITCZ on diurnal to monthly time scales in which mesoscale convectively coupled Rossby waves in the ITCZ are modulated by a large-...

Joseph A. Biello; Andrew J. Majda

2013-04-01T23:59:59.000Z

105

Multiscale Models of Quantum Dot Based Nanomaterials and Nanodevices for Solar Cells  

Science Conference Proceedings (OSTI)

NASA future exploration missions and space electronic equipment require improvements in solar cell efficiency and radiation hardness. Novel nano-engineered materials and quantum-dot (QD) based photovoltaic devices promise to deliver more efficient, lightweight, ... Keywords: Nanostructured solar cell, computer-aided design, drift-diffusion, hydrodynamics, intermediate band solar cells, multiscale, nanostructures, photovoltaic, quantum dot

Alexander I. Fedoseyev; Marek Turowski; Ashok Raman; Qinghui Shao; Alexander A. Balandin

2008-06-01T23:59:59.000Z

106

A Multiscale Model for the Planetary and Synoptic Motions in the Atmosphere  

Science Conference Proceedings (OSTI)

A reduced asymptotic model valid for the planetary and synoptic scales in the atmosphere is presented. The model is derived by applying a systematic multiple scales asymptotic method to the full compressible flow equations in spherical geometry. ...

S. I. Dolaptchiev; R. Klein

107

A Multiscale Model for the Planetary and Synoptic Motions in the Atmosphere  

Science Conference Proceedings (OSTI)

A reduced asymptotic model valid for the planetary and synoptic scales in the atmosphere is presented. The model is derived by applying a systematic multiple-scales asymptotic method to the full compressible-flow equations in spherical geometry. ...

Stamen I. Dolaptchiev; Rupert Klein

2013-09-01T23:59:59.000Z

108

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part I: Large-Scale and Storm-Scale Evolutions  

Science Conference Proceedings (OSTI)

The Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model, successfully simulated the life cycle of Tropical Storm Isobel that formed over the Timor Sea in the austral summer of 2006. The multiscale ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

109

Multiscale Modeling of Grain Boundary Segregation and Embrittlement in Tungsten for Mechanistic Design of Alloys for Coal Fired Plants  

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

Fairbanks, AK * Morgantown, WV * Pittsburgh, PA * Sugar Land, TX Fairbanks, AK * Morgantown, WV * Pittsburgh, PA * Sugar Land, TX Website: www.netl.doe.gov Customer Service: 1-800-553-7681 Multiscale Modeling of Grain Boundary Segregation and Embrittlement in Tungsten for Mechanistic Design of Alloys for Coal Fired Plants Background The Department of Energy (DOE) National Energy Technology Laboratory (NETL) University Coal Research (UCR) Program seeks to further develop the understanding of coal utilization. Since the program's inception in 1979, its primary objectives have been to improve our understanding of the chemical and physical processes involved in the conversion and utilization of coal in an environmentally acceptable manner; maintain and upgrade the coal research capabilities and facilities of U.S. colleges and

110

Fast computation of multi-scale combustion systems  

E-Print Network (OSTI)

In the present work, we illustrate the process of constructing a simplified model for complex multi-scale combustion systems. To this end, reduced models of homogeneous ideal gas mixtures of methane and air are first obtained by the novel Relaxation Redistribution Method (RRM) and thereafter used for the extraction of all the missing variables in a reactive flow simulation with a global reaction model.

Chiavazzo, Eliodoro; Asinari, Pietro

2010-01-01T23:59:59.000Z

111

Multiscale Problems: Numerical Analysis and Scientific Computing  

E-Print Network (OSTI)

Underground Nuclear Longterm Disposal of Radioactive Waste Underground Reactor Safety: Neutron Diffusion Multilevel Iterative Methods (homogeneous coefficients in PDE) Multigrid, AMG, DDM (with theory!) R. Scheichl theory!) Multiscale/Upscaling Methods (heterogeneous coefficients in PDE) Homogenisation (with theory

Mitchener, Paul

112

Language pyramid and multi-scale text analysis  

Science Conference Proceedings (OSTI)

The classical Bag-of-Word (BOW) model represents a document as a histogram of word occurrence, losing the spatial information that is invaluable for many text analysis tasks. In this paper, we present the Language Pyramid (LaP) model, which ... Keywords: bag of word, language pyramid, multi-scale language models, multi-scale text analysis, multi-scale text kernel, text spatial contents modeling

Shuang-Hong Yang; Hongyuan Zha

2010-10-01T23:59:59.000Z

113

Multiscale modeling of the influence of Fe content in a Al-Si-Cu alloy on the size distribution of intermetallic phases and micropores  

Science Conference Proceedings (OSTI)

A multiscale model was developed to simulate the formation of Fe-rich intermetallics and pores in quaternary Al-Si-Cu-Fe alloys. At the microscale, the multicomponent diffusion equations were solved for multiphase (liquid-solid-gas) materials via a finite difference framework to predict microstructure formation. A fast and robust decentered plate algorithm was developed to simulate the strong anisotropy of the solid/liquid interfacial energy for the Fe-rich intermetallic phase. The growth of porosity was controlled by local pressure drop due to solidification and interactions with surrounding solid phases, in addition to hydrogen diffusion. The microscale model was implemented as a subroutine in a commercial finite element package, producing a coupled multiscale model. This allows the influence of varying casting conditions on the Fe-rich intermetallics, the pores, and their interactions to be predicted. Synchrotron x-ray tomography experiments were performed to validate the model by comparing the three-dimensional morphology and size distribution of Fe-rich intermetallics as a function of Fe content. Large platelike Fe-rich {beta} intermetallics were successfully simulated by the multiscale model and their influence on pore size distribution in shape castings was predicted as a function of casting conditions.

Wang Junsheng; Lee, Peter D. [Department of Materials, Imperial College London, South Kensington Campus, Prince Consort Road, London SW7 2AZ (United Kingdom); Li Mei; Allison, John [Materials Research and Advanced Engineering Department, Ford Research Laboratory, Dearborn, Michigan 48121-2053 (United States)

2010-03-15T23:59:59.000Z

114

Procedure to construct a multi-scale coarse-grained model of DNA-coated colloids from experimental data  

E-Print Network (OSTI)

We present a quantitative, multi-scale coarse-grained model of DNA coated colloids. The parameters of this model are transferable and are solely based on experimental data. As a test case, we focus on nano-sized colloids carrying single-stranded DNA strands of length comparable to the colloids' size. We show that in this regime, the common theoretical approach of assuming pairwise additivity of the colloidal pair interactions leads to quantitatively and sometimes even qualitatively wrong predictions of the phase behaviour of DNA-grafted colloids. Comparing to experimental data, we find that our coarse-grained model correctly predicts the equilibrium structure and melting temperature of the formed solids. Due to limited experimental information on the persistence length of single-stranded DNA, some quantitative discrepancies are found in the prediction of spatial quantities. With the availability of better experimental data, the present approach provides a path for the rational design of DNA-functionalised building blocks that can self-assemble in complex, three-dimensional structures.

Bianca M. Mladek; Julia Fornleitner; Francisco J. Martinez-Veracoechea; Alexandre Dawid; Daan Frenkel

2013-05-03T23:59:59.000Z

115

On-line Chemistry within WRF: Description and Evaluation of a State-of-the-Art Multiscale Air Quality and Weather Prediction Model  

SciTech Connect

This is a conference proceeding that is now being put together as a book. This is chapter 2 of the book: "INTEGRATED SYSTEMS OF MESO-METEOROLOGICAL AND CHEMICAL TRANSPORT MODELS" published by Springer. The chapter title is "On-line Chemistry within WRF: Description and Evaluation of a State-of-the-Art Multiscale Air Quality and Weather Prediction Model." The original conference was the COST-728/NetFAM workshop on Integrated systems of meso-meteorological and chemical transport models, Danish Meteorological Institute, Copenhagen, May 21-23, 2007.

Grell, Georg; Fast, Jerome D.; Gustafson, William I.; Peckham, Steven E.; McKeen, Stuart A.; Salzmann, Marc; Freitas, Saulo

2010-01-01T23:59:59.000Z

116

MULTISCALE PHENOMENA IN MATERIALS  

Science Conference Proceedings (OSTI)

This project developed and supported a technology base in nonequilibrium phenomena underpinning fundamental issues in condensed matter and materials science, and applied this technology to selected problems. In this way the increasingly sophisticated synthesis and characterization available for classes of complex electronic and structural materials provided a testbed for nonlinear science, while nonlinear and nonequilibrium techniques helped advance our understanding of the scientific principles underlying the control of material microstructure, their evolution, fundamental to macroscopic functionalities. The project focused on overlapping areas of emerging thrusts and programs in the Los Alamos materials community for which nonlinear and nonequilibrium approaches will have decisive roles and where productive teamwork among elements of modeling, simulations, synthesis, characterization and applications could be anticipated--particularly multiscale and nonequilibrium phenomena, and complex matter in and between fields of soft, hard and biomimetic materials. Principal topics were: (i) Complex organic and inorganic electronic materials, including hard, soft and biomimetic materials, self-assembly processes and photophysics; (ii) Microstructure and evolution in multiscale and hierarchical materials, including dynamic fracture and friction, dislocation and large-scale deformation, metastability, and inhomogeneity; and (iii) Equilibrium and nonequilibrium phases and phase transformations, emphasizing competing interactions, frustration, landscapes, glassy and stochastic dynamics, and energy focusing.

A. BISHOP

2000-09-01T23:59:59.000Z

117

Domain reduction method for atomistic simulations  

Science Conference Proceedings (OSTI)

In this paper, a quasi-static formulation of the method of multi-scale boundary conditions (MSBCs) is derived and applied to atomistic simulations of carbon nano-structures, namely single graphene sheets and multi-layered graphite. This domain reduction ... Keywords: atomistic simulation, carbon nano-structures, deformable boundary, domain reduction, graphite, multi-scale modeling, nano-indentation

Sergey N. Medyanik; Eduard G. Karpov; Wing Kam Liu

2006-11-01T23:59:59.000Z

118

Multiscale Performance of the ALARO-0 Model for Simulating Extreme Summer Precipitation Climatology in Belgium  

Science Conference Proceedings (OSTI)

Daily summer precipitation over Belgium from the Aire Limitée Adaptation Dynamique Développement International (ALADIN) model and a version of the model that has been updated with physical parameterizations, the so-called ALARO-0 model [ALADIN and ...

Rozemien De Troch; Rafiq Hamdi; Hans Van de Vyver; Jean-François Geleyn; Piet Termonia

2013-11-01T23:59:59.000Z

119

Modeling, Analysis and Simulation of Multiscale Preferential Flow - 8/05-8/10 - Final Report  

SciTech Connect

The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

Ralph Showalter; Malgorzata Peszynska

2012-07-03T23:59:59.000Z

120

A Multiscale Nonhydrostatic Atmospheric Model Using Centroidal Voronoi Tesselations and C-Grid Staggering  

Science Conference Proceedings (OSTI)

The formulation of a fully compressible nonhydrostatic atmospheric model called the Model for Prediction Across Scales–Atmosphere (MPAS-A) is described. The solver is discretized using centroidal Voronoi meshes and a C-grid staggering of the ...

William C. Skamarock; Joseph B. Klemp; Michael G. Duda; Laura D. Fowler; Sang-Hun Park; Todd D. Ringler

2012-09-01T23:59:59.000Z

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


121

A new computational paradigm in multiscale simulations: application to brain blood flow  

Science Conference Proceedings (OSTI)

Interfacing atomistic-based with continuum-based simulation codes is now required in many multiscale physical and biological systems. We present the computational advances that have enabled the first multiscale simulation on 190,740 processors by coupling ... Keywords: cerebrovascular circulation, continuum-atomistic simulations, coupled solvers, multi-scale modeling

Leopold Grinberg; Joseph A. Insley; Vitali Morozov; Michael E. Papka; George Em Karniadakis; Dmitry Fedosov; Kalyan Kumaran

2011-11-01T23:59:59.000Z

122

A Multiscale Model for Efficient Simulation of a Membrane Bound Viral Fusion Peptide  

Science Conference Proceedings (OSTI)

Biomolecular simulations have been particularly useful in providing atomic-level insights into biological processes. The simulations can be conducted at atomistic or coarse- grained resolution. An atomistic simulation can model atomic details of a biological ...

Yudong Sun; Steve McKeever; Kia Balali-Mood; Mark S. P. Sansom

2007-11-01T23:59:59.000Z

123

A Multiscale Remote Sensing Model for Disaggregating Regional Fluxes to Micrometeorological Scales  

Science Conference Proceedings (OSTI)

Disaggregation of regional-scale (103 m) flux estimates to micrometeorological scales (101–102 m) facilitates direct comparison between land surface models and ground-based observations. Inversely, it also provides a means for upscaling flux-...

Martha C. Anderson; J. M. Norman; John R. Mecikalski; Ryan D. Torn; William P. Kustas; Jeffrey B. Basara

2004-04-01T23:59:59.000Z

124

A Multiscale Model for the Simulation of V.A.R. Ingot Solidification  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

125

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators  

E-Print Network (OSTI)

A new generation of laser wakefield accelerators, supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modeling for further understanding of the underlying physics and identification of optimal regimes, but large scale modeling of these scenarios is computationally heavy and requires efficient use of state-of-the-art Petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed / shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modeling of LWFA, demonstrating speedups of over 1 order of magni...

Fonseca, Ricardo A; Fiúza, Frederico; Davidson, Asher; Tsung, Frank S; Mori, Warren B; Silva, Luís O

2013-01-01T23:59:59.000Z

126

The G-Scheme: A framework for multi-scale adaptive model reduction  

Science Conference Proceedings (OSTI)

The numerical solution of mathematical models for reaction systems in general, and reacting flows in particular, is a challenging task because of the simultaneous contribution of a wide range of time scales to the system dynamics. However, the dynamics ... Keywords: 02.30.Hq, 02.30.Jr, 02.60.-x, 02.70.2c, 37Lxx, 37Mxx, 47.70.Fw, 76V05, 80A30, 80A32, 82.40.-g, Model reduction, Multiple time scales, Singular perturbation analysis, Stiff problems

M. Valorani; S. Paolucci

2009-07-01T23:59:59.000Z

127

SMART: A Stochastic Multiscale Model for the Analysis of Energy Resources, Technology, and Policy  

Science Conference Proceedings (OSTI)

We address the problem of modeling energy resource allocation, including dispatch, storage, and the long-term investments in new technologies, capturing different sources of uncertainty such as energy from wind, demands, prices, and rainfall. We also ... Keywords: analysis of algorithms, artificial intelligence, queues, simulation, statistical analysis

Warren B. Powell; Abraham George; Hugo Simão; Warren Scott; Alan Lamont; Jeffrey Stewart

2012-10-01T23:59:59.000Z

128

Building simple multiscale visualizations of outcrop geology using virtual reality modeling language (VRML)  

Science Conference Proceedings (OSTI)

Geological data collected from outcrop are inherently three-dimensional (3D) and span a variety of scales, from the megascopic to the microscopic. This presents challenges in both interpreting and communicating observations. The Virtual Reality Modeling ... Keywords: Carbonates, GIS, Mud-mounds, Photorealistic, VRML

John B. Thurmond; Peter A. Drzewiecki; Xueming Xu

2005-08-01T23:59:59.000Z

129

Computational upscaled modeling of heterogeneous porous media flow utilizing finite volume method  

E-Print Network (OSTI)

In this dissertation we develop and analyze numerical method to solve general elliptic boundary value problems with many scales. The numerical method presented is intended to capture the small scales e?ect on the large scale solution without resolving the small scale details, which is done through the construction of a multiscale map. The multiscale method is more e?ective when the coarse element size is larger than the small scale length. To guarantee a numerical conservation, a ?nite volume element method is used to construct the global problem. Analysis of the multiscale method is separately done for cases of linear and nonlinear coe?cients. For linear coe?cients, the multiscale ?nite volume element method is viewed as a perturbation of multiscale ?nite element method. The analysis uses substantially the existing ?nite element results and techniques. The multiscale method for nonlinear coe?cients will be analyzed in the ?nite element sense. A class of correctors corresponding to the multiscale method will be discussed. In turn, the analysis will rely on approximation properties of this correctors. Several numerical experiments verifying the theoretical results will be given. Finally we will present several applications of the multiscale method in the ?ow in porous media. Problems that we will consider are multiphase immiscible ?ow, multicomponent miscible ?ow, and soil in?ltration in saturated/unsaturated ?ow.

Ginting, Victor Eralingga

2003-05-01T23:59:59.000Z

130

Electronic poster: visualizing multiscale simulation data  

Science Conference Proceedings (OSTI)

Accurately modeling many physical and biological systems requires simulating at multiple scales. This results in large and heterogeneous data sets on vastly differing scales, both physical and temporal. Here we look specifically at blood flow in a patient-specific ... Keywords: modeling, multi-scale, visualization

Joseph A. Insley; Leopold Grinberg; Michael E. Papka; George Karniadakis

2011-11-01T23:59:59.000Z

131

Generalized multiscale radial basis function networks  

Science Conference Proceedings (OSTI)

A novel modelling framework is proposed for constructing parsimonious and flexible multiscale radial basis function networks (RBF). Unlike a conventional standard single scale RBF network, where all the basis functions have a common kernel width, the ... Keywords: Model term selection, Neural networks, Nonlinear system identification, Orthogonal least squares, Radial basis functions

Stephen A. Billings; Hua-Liang Wei; Michael A. Balikhin

2007-12-01T23:59:59.000Z

132

A Comparison of Simulated Cloud Radar Output from the Multiscale Modeling Framework Global Climate Model with CloudSat Cloud Radar Observations  

Science Conference Proceedings (OSTI)

Over the last few years a new type of global climate model (GCM) has emerged in which a cloud-resolving model is embedded into each grid cell of a GCM. This new approach is frequently called a multiscale modeling framework (MMF) or superparameterization. In this article we present a comparison of MMF output with radar observations from the NASA CloudSat mission, which uses a near-nadir-pointing millimeter-wavelength radar to probe the vertical structure of clouds and precipitation. We account for radar detection limits by simulating the 94 GHz radar reflectivity that CloudSat would observe from the high-resolution cloud-resolving model output produced by the MMF. Overall, the MMF does a good job of reproducing the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks, as well as their changes in position with the annual solar cycle. Nonetheless, the comparison also reveals a number of model shortfalls including (1) excessive hydrometeor coverage at all altitudes over many convectively active regions, (2) a lack of low-level hydrometeors over all subtropical oceanic basins, (3) excessive low-level hydrometeor coverage (principally precipitating hydrometeors) in the midlatitude storm tracks of both hemispheres during the summer season (in each hemisphere), and (4) a thin band of low-level hydrometeors in the Southern Hemisphere of the central (and at times eastern and western) Pacific in the MMF, which is not observed by CloudSat. This band resembles a second much weaker ITCZ but is restricted to low levels.

Marchand, Roger T.; Haynes, J. M.; Mace, Gerald G.; Ackerman, Thomas P.; Stephens, Graeme L.

2009-01-13T23:59:59.000Z

133

Equation-Free Multiscale Computations in Social Networks: from Agent-based Modelling to Coarse-grained Stability and Bifurcation Analysis  

E-Print Network (OSTI)

We focus at the interface between multiscale computations, bifurcation theory and social networks. In particular we address how the Equation-Free approach, a recently developed computational framework, can be exploited to systematically extract coarse-grained, emergent dynamical information by bridging detailed, agent-based models of social interactions on networks, with macroscopic, systems-level, continuum numerical analysis tools. For our illustrations we use a simple dynamic agent-based model describing the propagation of information between individuals interacting under mimesis in a social network with private and public information. We describe the rules governing the evolution of the agents emotional state dynamics and discover, through simulation, multiple stable stationary states as a function of the network topology. Using the Equation-Free approach we track the dependence of these stationary solutions on network parameters and quantify their stability in the form of coarse-grained bifurcation diagr...

Tsoumanis, A C; Kevrekidis, Yu G; Bafas, G V

2009-01-01T23:59:59.000Z

134

Dynamic Multiscale Averaging (DMA) of Turbulent Flow  

SciTech Connect

A new approach called dynamic multiscale averaging (DMA) for computing the effects of turbulent flow is described. The new method encompasses multiple applications of temporal and spatial averaging, that is, multiscale operations. Initially, a direct numerical simulation (DNS) is performed for a relatively short time; it is envisioned that this short time should be long enough to capture several fluctuating time periods of the smallest scales. The flow field variables are subject to running time averaging during the DNS. After the relatively short time, the time-averaged variables are volume averaged onto a coarser grid. Both time and volume averaging of the describing equations generate correlations in the averaged equations. These correlations are computed from the flow field and added as source terms to the computation on the next coarser mesh. They represent coupling between the two adjacent scales. Since they are computed directly from first principles, there is no modeling involved. However, there is approximation involved in the coupling correlations as the flow field has been computed for only a relatively short time. After the time and spatial averaging operations are applied at a given stage, new computations are performed on the next coarser mesh using a larger time step. The process continues until the coarsest scale needed is reached. New correlations are created for each averaging procedure. The number of averaging operations needed is expected to be problem dependent. The new DMA approach is applied to a relatively low Reynolds number flow in a square duct segment. Time-averaged stream-wise velocity and vorticity contours from the DMA approach appear to be very similar to a full DNS for a similar flow reported in the literature. Expected symmetry for the final results is produced for the DMA method. The results obtained indicate that DMA holds significant potential in being able to accurately compute turbulent flow without modeling for practical engineering applications.

Richard W. Johnson

2012-09-01T23:59:59.000Z

135

Multiscale Modeling and Applications  

Science Conference Proceedings (OSTI)

Mar 6, 2013 ... Room: Lone Star Salon B Location: Grand Hyatt Session Chair: Yunzhi Wang, The Ohio State University; Darren Hartl, Texas A&M University ...

136

Multiscale Modeling of Materials  

Science Conference Proceedings (OSTI)

Oct 27, 2009 ... Parametric materials design integrating materials science, applied mechanics and quantum physics within a systems engineering framework ...

137

Numerical modeling of electrochemical-mechanical interactions in lithium polymer batteries  

Science Conference Proceedings (OSTI)

This paper presents a multi-scale finite element approach for lithium batteries to study electrochemical-mechanical interaction phenomena at macro- and micro-scales. The battery model consists of a lithium foil anode, a separator, and a porous cathode ... Keywords: Finite element method, Homogenization, Multi-scale modeling, Porous electrode theory

Stephanie Golmon; Kurt Maute; Martin L. Dunn

2009-12-01T23:59:59.000Z

138

Multiscale Convective Organization and the YOTC Virtual Global Field Campaign  

Science Conference Proceedings (OSTI)

The Year of Tropical Convection (YOTC) project recognizes that major improvements are needed in how the tropics are represented in climate models. Tropical convection is organized into multiscale precipitation systems with an underlying chaotic order. ...

Mitchell W. Moncrieff; Duane E. Waliser; Martin J. Miller; Melvyn A. Shapiro; Ghassem R. Asrar; James Caughey

2012-08-01T23:59:59.000Z

139

Stratospheric Gravity Waves Generated by Multiscale Tropical Convection  

Science Conference Proceedings (OSTI)

The generation of gravity waves by multiscale cloud systems evolving in an initially motionless and thermodynamically uniform environment is explored using a two-dimensional cloud-system-resolving model. The simulated convection has similar depth ...

Todd P. Lane; Mitchell W. Moncrieff

2008-08-01T23:59:59.000Z

140

Evaluating Low-Cloud Simulation from an Upgraded Multiscale Modeling Framework Model. Part II: Seasonal Variations over the Eastern Pacific  

Science Conference Proceedings (OSTI)

The eastern Pacific is a climatologically important region. Conventional coupled atmosphere–ocean general circulation models produce positive sea surface temperature biases of 2–5 K in this region because of insufficient stratocumulus clouds. In ...

Kuan-Man Xu; Anning Cheng

2013-08-01T23:59:59.000Z

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


141

From systems biology to photosynthesis and whole-plant modeling: a conceptual model for integrating multi-scale networks  

SciTech Connect

Network analysis is now a common statistical tool for molecular biologists. Network algorithms are readily used to model gene, protein and metabolic correlations providing insight into pathways driving biological phenomenon. One output from such an analysis is a candidate gene list that can be responsible, in part, for the biological process of interest. The question remains, however, as to whether molecular network analysis can be used to inform process models at higher levels of biological organization. In our previous work, transcriptional networks derived from three plant species were constructed, interrogated for orthology and then correlated to photosynthetic inhibition at elevated temperature. One unique aspect of that study was the link from co-expression networks to net photosynthesis. In this addendum, we propose a conceptual model where traditional network analysis can be linked to whole-plant models thereby informing predictions on key processes such as photosynthesis, nutrient uptake and assimilation, and C partitioning.

Weston, David [ORNL; Hanson, Paul J [ORNL; Norby, Richard J [ORNL; Tuskan, Gerald A [ORNL; Wullschleger, Stan D [ORNL

2012-01-01T23:59:59.000Z

142

An iterative multiscale finite volume algorithm converging to the exact solution  

Science Conference Proceedings (OSTI)

The multiscale finite volume (MsFV) method has been developed to efficiently solve large heterogeneous problems (elliptic or parabolic); it is usually employed for pressure equations and delivers conservative flux fields to be used in transport problems. ... Keywords: Conservative methods, Domain decomposition, Linear solver, Multiscale finite volume method, Preconditioner splitting, Projection methods

Ivan Lunati; Manav Tyagi; Seong H. Lee

2011-03-01T23:59:59.000Z

143

A Multiscale Four-Dimensional Data Assimilation System Applied in the San Joaquin Valley during SARMAP. Part I: Modeling Design and Basic Performance Characteristics  

Science Conference Proceedings (OSTI)

This paper presents results of numerical simulations made with a high-resolution multiscale four-dimensional data assimilation system applied over California during two episodes associated with high ozone concentrations in the San Joaquin Valley. ...

Nelson L. Seaman; David R. Stauffer; Annette M. Lario-Gibbs

1995-08-01T23:59:59.000Z

144

Multiscale framework for predicting the coupling between deformation and fluid diffusion in porous rocks  

SciTech Connect

In this project, a predictive multiscale framework will be developed to simulate the strong coupling between solid deformations and fluid diffusion in porous rocks. We intend to improve macroscale modeling by incorporating fundamental physical modeling at the microscale in a computationally efficient way. This is an essential step toward further developments in multiphysics modeling, linking hydraulic, thermal, chemical, and geomechanical processes. This research will focus on areas where severe deformations are observed, such as deformation bands, where classical phenomenology breaks down. Multiscale geometric complexities and key geomechanical and hydraulic attributes of deformation bands (e.g., grain sliding and crushing, and pore collapse, causing interstitial fluid expulsion under saturated conditions), can significantly affect the constitutive response of the skeleton and the intrinsic permeability. Discrete mechanics (DEM) and the lattice Boltzmann method (LBM) will be used to probe the microstructure---under the current state---to extract the evolution of macroscopic constitutive parameters and the permeability tensor. These evolving macroscopic constitutive parameters are then directly used in continuum scale predictions using the finite element method (FEM) accounting for the coupled solid deformation and fluid diffusion. A particularly valuable aspect of this research is the thorough quantitative verification and validation program at different scales. The multiscale homogenization framework will be validated using X-ray computed tomography and 3D digital image correlation in situ at the Advanced Photon Source in Argonne National Laboratories. Also, the hierarchical computations at the specimen level will be validated using the aforementioned techniques in samples of sandstone undergoing deformation bands.

Josà © E. Andrade; John W. Rudnicki

2012-12-14T23:59:59.000Z

145

Evaluating WRF-Chem multi-scale model in simulating aerosol radiative properties over the tropics – A case study over India  

Science Conference Proceedings (OSTI)

We utilized WRF-Chem multi-scale model to simulate the regional distribution of aerosols, optical properties and its effect on radiation over India for a winter month. The model is evaluated using measurements obtained from upper-air soundings, AERONET sun photometers, various satellite instruments, and pyranometers operated by the Indian Meteorological Department. The simulated downward shortwave flux was overestimated when the effect of aerosols on radiation and clouds was neglected. Downward shortwave radiation from a simulation that included aerosol-radiation interaction processes was 5 to 25 Wm{sup -2} closer to the observations, while a simulation that included aerosol-cloud interaction processes were another 1 to 20 Wm{sup -2} closer to the observations. For the few observations available, the model usually underestimated particulate concentration. This is likely due to turbulent mixing, transport errors and the lack of secondary organic aerosol treatment in the model. The model efficiently captured the broad regional hotspots such as high aerosol optical depth over Indo-Gangetic basin as well as the northwestern and southern part of India. The regional distribution of aerosol optical depth compares well with AVHRR aerosol optical depth and the TOMS aerosol index. The magnitude and wavelength-dependence of simulated aerosol optical depth was also similar to the AERONET observations across India. Differences in surface shortwave radiation between simulations that included and neglected aerosol-radiation interactions were as high as -25 Wm{sup -2}, while differences in surface shortwave radiation between simulations that included and neglect aerosol-radiation-cloud interactions were as high as -30 Wm{sup -2}. The spatial variations of these differences were also compared with AVHRR observation. This study suggests that the model is able to qualitatively simulate the impact of aerosols on radiation over India; however, additional measurements of particulate mass and composition are needed to fully evaluate whether the aerosol precursor emissions are adequate when simulating radiative forcing in the region.

Seethala, C.; Pandithurai, G.; Fast, Jerome D.; Polade, Suraj D.; Reddy, M. S.; Peckham, Steven E.

2012-01-24T23:59:59.000Z

146

Dynamically Consistent Formulations in Meteorological and Air Quality Models for Multiscale Atmospheric Studies. Part II: Mass Conservation Issues  

Science Conference Proceedings (OSTI)

Eulerian air quality models that require gridded meteorological inputs have to adapt to recent advances in meteorological models for fully compressible atmosphere. When the input meteorological data are recast with a robust fully compressible ...

Daewon W. Byun

1999-11-01T23:59:59.000Z

147

Institute for Multiscale Materials Studies  

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

focus is on graduate education and research in the area of multiscale materials and mechanics. Contact Leader Ed Kober (505) 663-5623 Email LANL Administrator Jean Knowlton (505)...

148

Multi-Scale Multi-Dimensional Li-Ion Battery Model for Better Design and Management (Presentation)  

DOE Green Energy (OSTI)

The developed model used is to provide a better understanding and help answer engineering questions about improving the design, operational strategy, management, and safety of cells.

Kim, G.-H.; Smith, K.

2008-10-01T23:59:59.000Z

149

Evaluation Study for Large Prismatic Lithium-Ion Cell Designs Using Multi-Scale Multi-Dimensional Battery Model (Presentation)  

Science Conference Proceedings (OSTI)

Addresses battery requirements for electric vehicles using a model that evaluates physical-chemical processes in lithium-ion batteries, from atomic variations to vehicle interface controls.

Kim, G. H.; Smith, K.

2009-05-01T23:59:59.000Z

150

Retinal vessel segmentation using multiwavelet kernels and multiscale hierarchical decomposition  

Science Conference Proceedings (OSTI)

We propose a comprehensive method for segmenting the retinal vasculature in fundus camera images. Our method does not require preprocessing and training and can therefore be used directly on different images sets. We enhance the vessels using matched ... Keywords: Matched filter, Multiscale hierarchical decomposition, Multiwavelet, Retinal images, Segmentation, Vessel detection

Yangfan Wang; Guangrong Ji; Ping Lin; Emanuele Trucco

2013-08-01T23:59:59.000Z

151

Toward an understanding of vertical momentum transports in cloud system resolving model simulations of multiscale tropical convection  

Science Conference Proceedings (OSTI)

This study examines the characteristics of convective momentum transport (CMT) and gravity wave momentum transport (GWMT) in two-dimensional cloud-system resolving model simulations, including the relationships between the two transports. A linear ...

Tiffany A. Shaw; Todd P. Lane

152

Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers  

E-Print Network (OSTI)

In this supplementary material, we recollect, for reader's convenience, the general scheme of suggested multiscale model (Sec. 1), and basic informations about approaches used for pilot study: a detailed description of the interaction model (Sec. 2) and dynamical methods used for the dark dynamics step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition, a detailed description of the treatment of radiative processes is also given (Sec. 4).

Jane?ek, Ivan; Naar, Pavel; Renard, Frederic; Kalus, René; Gadéa, Florent X

2012-01-01T23:59:59.000Z

153

Second-order accurate projective integrators for multiscale problems  

Science Conference Proceedings (OSTI)

We introduce new projective versions of second-order accurate Runge-Kutta and Adams-Bashforth methods, and demonstrate their use as outer integrators in solving stiff differential systems. An important outcome is that the new outer integrators, when ... Keywords: Explicit, Multiscale, Parabolic, Stability, Stiff, Teleprojective integration

Steven L. Lee; C. William Gear

2007-04-01T23:59:59.000Z

154

Design, fabrication and mechanical optimization of multi-scale anisotropic feet for terrestrial locomotion  

E-Print Network (OSTI)

Multi-scale surface interaction methods have been studied to achieve optimal locomotion over surface features of differing length scales. It has been shown that anisotropy is a convenient way of transferring an undirected ...

Morin, Jeffrey W. (Jeffrey William)

2011-01-01T23:59:59.000Z

155

Peridynamics as a rigorous coarse-graining of atomistics for multiscale materials design.  

Science Conference Proceedings (OSTI)

This report summarizes activities undertaken during FY08-FY10 for the LDRD Peridynamics as a Rigorous Coarse-Graining of Atomistics for Multiscale Materials Design. The goal of our project was to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. The goal of our project is to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. Our coarse-graining overcomes the intrinsic limitation of coupling atomistics with classical continuum mechanics via the FEM (finite element method), SPH (smoothed particle hydrodynamics), or MPM (material point method); namely, that classical continuum mechanics assumes a local force interaction that is incompatible with the nonlocal force model of atomistic methods. Therefore FEM, SPH, and MPM inherit this limitation. This seemingly innocuous dichotomy has far reaching consequences; for example, classical continuum mechanics cannot resolve the short wavelength behavior associated with atomistics. Other consequences include spurious forces, invalid phonon dispersion relationships, and irreconcilable descriptions/treatments of temperature. We propose a statistically based coarse-graining of atomistics via peridynamics and so develop a first of a kind mesoscopic capability to enable consistent, thermodynamically sound, atomistic-to-continuum (AtC) multiscale material simulation. Peridynamics (PD) is a microcontinuum theory that assumes nonlocal forces for describing long-range material interaction. The force interactions occurring at finite distances are naturally accounted for in PD. Moreover, PDs nonlocal force model is entirely consistent with those used by atomistics methods, in stark contrast to classical continuum mechanics. Hence, PD can be employed for mesoscopic phenomena that are beyond the realms of classical continuum mechanics and atomistic simulations, e.g., molecular dynamics and density functional theory (DFT). The latter two atomistic techniques are handicapped by the onerous length and time scales associated with simulating mesoscopic materials. Simulating such mesoscopic materials is likely to require, and greatly benefit from multiscale simulations coupling DFT, MD, PD, and explicit transient dynamic finite element methods FEM (e.g., Presto). The proposed work fills the gap needed to enable multiscale materials simulations.

Lehoucq, Richard B.; Aidun, John Bahram; Silling, Stewart Andrew; Sears, Mark P.; Kamm, James R.; Parks, Michael L.

2010-09-01T23:59:59.000Z

156

Method and apparatus for modeling interactions  

DOE Patents (OSTI)

The present invention provides a method and apparatus for modeling interactions that overcomes drawbacks. The method of the present invention comprises representing two bodies undergoing translations by two swept volume representations. Interactions such as nearest approach and collision can be modeled based on the swept body representations. The present invention is more robust and allows faster modeling than previous methods.

Xavier, Patrick G. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

157

Linking the Eta Model with the Community Multiscale Air Quality (CMAQ) Modeling System to Build a National Air Quality Forecasting System  

Science Conference Proceedings (OSTI)

NOAA and the U.S. Environmental Protection Agency (EPA) have developed a national air quality forecasting (AQF) system that is based on numerical models for meteorology, emissions, and chemistry. The AQF system generates gridded model forecasts ...

Tanya L. Otte; George Pouliot; Jonathan E. Pleim; Jeffrey O. Young; Kenneth L. Schere; David C. Wong; Pius C. S. Lee; Marina Tsidulko; Jeffery T. McQueen; Paula Davidson; Rohit Mathur; Hui-Ya Chuang; Geoff DiMego; Nelson L. Seaman

2005-06-01T23:59:59.000Z

158

Bayesian methods in music modelling  

E-Print Network (OSTI)

Expectation-maximization algorithm MCMC Markov Chain Monte Carlo MH Metropolis-Hastings GMM Gaussian mixture model ACF Autocorrelation function SNR Signal-noise ratio 2 Contents 1 Introduction 12 1.1 Background...

Peeling, Paul

2011-03-15T23:59:59.000Z

159

Plume-in-Grid Modeling in Central California Using CMAQ-APT (Comprehensive Multiscale Air Quality Model with Advanced Plume Treatmen t)  

Science Conference Proceedings (OSTI)

CMAQ-APT, a state-of-the-science plume-in-grid (PiG) air quality model, has been updated and applied to the ten largest nitrogen oxides (NOx) emitting facilities in central California. This report discusses the results of that modeling study.

2005-02-21T23:59:59.000Z

160

Multiscale characterization and analysis of shapes  

SciTech Connect

An adaptive multiscale method approximates shapes with continuous or uniformly and densely sampled contours, with the purpose of sparsely and nonuniformly discretizing the boundaries of shapes at any prescribed resolution, while at the same time retaining the salient shape features at that resolution. In another aspect, a fundamental geometric filtering scheme using the Constrained Delaunay Triangulation (CDT) of polygonized shapes creates an efficient parsing of shapes into components that have semantic significance dependent only on the shapes' structure and not on their representations per se. A shape skeletonization process generalizes to sparsely discretized shapes, with the additional benefit of prunability to filter out irrelevant and morphologically insignificant features. The skeletal representation of characters of varying thickness and the elimination of insignificant and noisy spurs and branches from the skeleton greatly increases the robustness, reliability and recognition rates of character recognition algorithms.

Prasad, Lakshman (Los Alamos, NM); Rao, Ramana (Sunnyvale, CA)

2002-01-01T23:59:59.000Z

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


161

A Collaborative Informatics Infrastructure for Multi-Scale Science  

Science Conference Proceedings (OSTI)

The Collaboratory for Multi-scale Chemical Science (CMCS) is developing a powerful informatics-based approach to synthesizing multi-scale information in support of systems-based research and is applying it within combustion science. An open source multi-scale ... Keywords: collaboratory, community data, cyberenvironment, knowledge grid, multi-scale data, provenance, system science

James D. Myers; Thomas C. Allison; Sandra Bittner; Brett Didier; Michael Frenklach; William H. Green, Jr.; Yen-Ling Ho; John Hewson; Wendy Koegler; Carina Lansing; David Leahy; Michael Lee; Renata Mccoy; Michael Minkoff; Sandeep Nijsure; Gregor Von Laszewski; David Montoya; Luwi Oluwole; Carmen Pancerella; Reinhardt Pinzon; William Pitz; Larry A. Rahn; Branko Ruscic; Karen Schuchardt; Eric Stephan; A. Wagner; Theresa Windus; Christine Yang

2005-10-01T23:59:59.000Z

162

A hybrid Godunov method for radiation hydrodynamics  

Science Conference Proceedings (OSTI)

From a mathematical perspective, radiation hydrodynamics can be thought of as a system of hyperbolic balance laws with dual multiscale behavior (multiscale behavior associated with the hyperbolic wave speeds as well as multiscale behavior associated ... Keywords: Asymptotic preserving, Godunov method, Radiation hydrodynamics

Michael D. Sekora; James M. Stone

2010-09-01T23:59:59.000Z

163

A Multiscale Analysis of the Extreme Weather Events over Western Russia and Northern Pakistan during July 2010  

Science Conference Proceedings (OSTI)

This manuscript presents a detailed multiscale analysis—using observations, model analyses, and ensemble forecasts—of the extreme heat wave over Russia and historic floods over Pakistan during late July 2010, with an emphasis on the floods over ...

Thomas J. Galarneau Jr.; Thomas M. Hamill; Randall M. Dole; Judith Perlwitz

2012-05-01T23:59:59.000Z

164

A Multi-scale Agent-Based Distributed Simulation Framework for Groundwater Pollution Management  

Science Conference Proceedings (OSTI)

Groundwater is like dark matter--we know very little apart from the fact that it is hugely important. Given the scarcity of data, mathematical modelling can come to the rescue but existing groundwater models are mainly restricted to simulate the transport ... Keywords: groundwater, bioremediation, distributed simulation, multi-scale modelling, agent-based systems, individual-based models

Susanne I. Schmidt; Cristian Picioreanu; Bart Craenen; Rae Mackay; Jan-Ulrich Kreft; Georgios Theodoropoulos

2011-09-01T23:59:59.000Z

165

Multiscale dynamics of solar magnetic structures  

E-Print Network (OSTI)

Multiscale topological complexity of solar magnetic field is among the primary factors controlling energy release in the corona, including associated processes in the photospheric and chromospheric boundaries. We present a new approach for analyzing multiscale behavior of the photospheric magnetic flux underlying this dynamics as depicted by a sequence of high-resolution solar magnetograms. The approach involves two basic processing steps: (1) identification of timing and location of magnetic flux origin and demise events (as defined by DeForest et al., 2007) by tracking spatiotemporal evolution of unipolar and bipolar photospheric regions, and (2) analysis of collective behavior of the detected magnetic events using a generalized version of Grassberger - Procaccia correlation integral algorithm. The scale-free nature of the developed algorithms makes it possible to characterize the dynamics of the photospheric network across a wide range of distances and relaxation times. Three types of photospheric conditions are considered to test the method: a quiet photosphere, a solar active region (NOAA 10365) in a quiescent non-flaring state, and the same active region during a period of M-class flares. The results obtained show (1) the presence of a topologically complex asymmetrically fragmented magnetic network in the quiet photosphere driven by meso- and supergranulation, (2) the formation of non-potential magnetic structures with complex polarity separation lines inside the active region, and (3) statistical signatures of canceling bipolar magnetic structures coinciding with flaring activity in the active region. Each of these effects can represent an unstable magnetic configuration acting as an energy source for coronal dissipation and heating.

Vadim M. Uritsky; Joseph M. Davila

2011-11-21T23:59:59.000Z

166

A Hierarchical Multiscale Approach to History Matching and Optimization for Reservoir Management in Mature Fields  

E-Print Network (OSTI)

Reservoir management typically focuses on maximizing oil and gas recovery from a reservoir based on facts and information while minimizing capital and operating investments. Modern reservoir management uses history-matched simulation model to predict the range of recovery or to provide the economic assessment of different field development strategies. Geological models are becoming increasingly complex and more detailed with several hundred thousand to million cells, which include large sets of subsurface uncertainties. Current issues associated with history matching, therefore, involve extensive computation (flow simulations) time, preserving geologic realism, and non-uniqueness problem. Many of recent rate optimization methods utilize constrained optimization techniques, often making them inaccessible for field reservoir management. Field-scale rate optimization problems involve highly complex reservoir models, production and facilities constraints and a large number of unknowns. We present a hierarchical multiscale calibration approach using global and local updates in coarse and fine grid. We incorporate a multiscale framework into hierarchical updates: global and local updates. In global update we calibrate large-scale parameters to match global field-level energy (pressure), which is followed by local update where we match well-by-well performances by calibration of local cell properties. The inclusion of multiscale calibration, integrating production data in coarse grid and successively finer grids sequentially, is critical for history matching high-resolution geologic models through significant reduction in simulation time. For rate optimization, we develop a hierarchical analytical method using streamline-assisted flood efficiency maps. The proposed approach avoids use of complex optimization tools; rather we emphasize the visual and the intuitive appeal of streamline method and utilize analytic solutions derived from relationship between streamline time of flight and flow rates. The proposed approach is analytic, easy to implement and well-suited for large-scale field applications. Finally, we present a hierarchical Pareto-based approach to history matching under conflicting information. In this work we focus on multiobjective optimization problem, particularly conflicting multiple objectives during history matching of reservoir performances. We incorporate Pareto-based multiobjective evolutionary algorithm and Grid Connectivity-based Transformation (GCT) to account for history matching with conflicting information. The power and effectiveness of our approaches have been demonstrated using both synthetic and real field cases.

Park, Han-Young

2012-08-01T23:59:59.000Z

167

Discrete Modeling via Function Approximation Methods: Bridging ...  

Science Conference Proceedings (OSTI)

The Monte-Carlo method requires energy computations at each time step in order to compute ... Figure B. The integration of thin-film generation and process modeling. ... Its application to magnet systems is well explored in the literature.

168

Lagrangian shock hydrodynamics on tetrahedral meshes: A stable and accurate variational multiscale approach  

Science Conference Proceedings (OSTI)

In the past, a number of attempts have failed to robustly compute highly transient shock hydrodynamics flows on tetrahedral meshes. To a certain degree, this is not a surprise, as prior attempts emphasized enhancing the structure of shock-capturing operators ... Keywords: Lagrangian shock hydrodynamics, Nodal finite element method, Stabilized methods, Tetrahedral grids, Updated Lagrangian formulation, Variational multiscale analysis

G. Scovazzi

2012-10-01T23:59:59.000Z

169

Crystal Plasticity Modeling on Single Crystal and Polycrystal of a ...  

Science Conference Proceedings (OSTI)

Multiscale Modeling of Fracture Resistance in TRIP-Assisted Multiphase Steels ... Statistical Failure Analysis of Crystallographically Isotropic Porous Materials.

170

The Application of Bayesian Neural Network Data Modeling to Study ...  

Science Conference Proceedings (OSTI)

A Continuum General Noise Brownian Thermostat with Applications to Film Morphology · A Multiscale, Nonlinear, Modeling Framework Enabling the Design and ...

171

Tools, Models, Databases and Simulation Tools Developed and ...  

Science Conference Proceedings (OSTI)

A Continuum General Noise Brownian Thermostat with Applications to Film Morphology · A Multiscale, Nonlinear, Modeling Framework Enabling the Design and ...

172

Regression modeling method of space weather prediction  

E-Print Network (OSTI)

A regression modeling method of space weather prediction is proposed. It allows forecasting Dst index up to 6 hours ahead with about 90% correlation. It can also be used for constructing phenomenological models of interaction between the solar wind and the magnetosphere. With its help two new geoeffective parameters were found: latitudinal and longitudinal flow angles of the solar wind. It was shown that Dst index remembers its previous values for 2000 hours.

Parnowski, Aleksei

2009-01-01T23:59:59.000Z

173

Multiscale edge detection based on Gaussian smoothing and edge tracking  

Science Conference Proceedings (OSTI)

The human vision is usually considered a multiscale, hierarchical knowledge extraction system. Inspired by this fact, multiscale techniques for computer vision perform a sequential analysis, driven by different interpretations of the concept of scale. ... Keywords: Edge detection, Edge tracking, Gaussian scale-space, Multiscale image processing, Sobel operators

C. Lopez-Molina; B. De Baets; H. Bustince; J. Sanz; E. Barrenechea

2013-05-01T23:59:59.000Z

174

Computer Aided Multi-scale Design of SiC-Si3N4 Nanoceramic Composites for High-Temperature Structural Applications  

SciTech Connect

It is estimated that by using better and improved high temperature structural materials, the power generation efficiency of the power plants can be increased by 15% resulting in significant cost savings. One such promising material system for future high-temperature structural applications in power plants is Silicon Carbide-Silicon Nitride (SiC-Si{sub 3}N{sub 4}) nanoceramic matrix composites. The described research work focuses on multiscale simulation-based design of these SiC-Si{sub 3}N{sub 4} nanoceramic matrix composites. There were two primary objectives of the research: (1) Development of a multiscale simulation tool and corresponding multiscale analyses of the high-temperature creep and fracture resistance properties of the SiC-Si{sub 3}N{sub 4} nanocomposites at nano-, meso- and continuum length- and timescales; and (2) Development of a simulation-based robust design optimization methodology for application to the multiscale simulations to predict the range of the most suitable phase morphologies for the desired high-temperature properties of the SiC-Si{sub 3}N{sub 4} nanocomposites. The multiscale simulation tool is based on a combination of molecular dynamics (MD), cohesive finite element method (CFEM), and continuum level modeling for characterizing time-dependent material deformation behavior. The material simulation tool is incorporated in a variable fidelity model management based design optimization framework. Material modeling includes development of an experimental verification framework. Using material models based on multiscaling, it was found using molecular simulations that clustering of the SiC particles near Si{sub 3}N{sub 4} grain boundaries leads to significant nanocomposite strengthening and significant rise in fracture resistance. It was found that a control of grain boundary thicknesses by dispersing non-stoichiometric carbide or nitride phases can lead to reduction in strength however significant rise in fracture strength. The temperature dependent strength and microstructural stability was also significantly depended upon the dispersion of new phases at grain boundaries. The material design framework incorporates high temperature creep and mechanical strength data in order to develop a collaborative multiscale framework of morphology optimization. The work also incorporates a computer aided material design dataset development procedure where a systematic dataset on material properties and morphology correlation could be obtained depending upon a material processing scientist's requirements. Two different aspects covered under this requirement are: (1) performing morphology related analyses at the nanoscale and at the microscale to develop a multiscale material design and analyses capability; (2) linking material behavior analyses with the developed design tool to form a set of material design problems that illustrate the range of material design dataset development that could be performed. Overall, a software based methodology to design microstructure of particle based ceramic nanocomposites has been developed. This methodology has been shown to predict changes in phase morphologies required for achieving optimal balance of conflicting properties such as minimal creep strain rate and high fracture strength at high temperatures. The methodology incorporates complex material models including atomistic approaches. The methodology will be useful to design materials for high temperature applications including those of interest to DoE while significantly reducing cost of expensive experiments.

Vikas Tomer; John Renaud

2010-08-31T23:59:59.000Z

175

A multiscale Molecular Dynamics approach to Contact Mechanics  

E-Print Network (OSTI)

The friction and adhesion between elastic bodies are strongly influenced by the roughness of the surfaces in contact. Here we develop a multiscale molecular dynamics approach to contact mechanics, which can be used also when the surfaces have roughness on many different length-scales, e.g., for self affine fractal surfaces. As an illustration we consider the contact between randomly rough surfaces, and show that the contact area varies linearly with the load for small load. We also analyze the contact morphology and the pressure distribution at different magnification, both with and without adhesion. The calculations are compared with analytical contact mechanics models based on continuum mechanics.

C. Yang; U. Tartaglino; B. N. J. Persson

2005-08-10T23:59:59.000Z

176

Biomass Model for the Egg Production Method  

E-Print Network (OSTI)

Biomass Model for the Egg Production Method KEITH PARKER' Southwest Fisheries Center, National estimable and constant over the field snmpling interval. Spawning biomass is then estimated as a function are derived and given. The relationship between the spawning biomass of a fish stock and its production

177

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part II: System-Scale and Mesoscale Processes  

Science Conference Proceedings (OSTI)

The life cycle of Tropical Storm Isobel was simulated reasonably well in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model. The evolution of the large-scale circulation and the storm-scale structure ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

178

Internet Resource Pricing Models, Mechanisms, and Methods  

E-Print Network (OSTI)

With the fast development of video and voice network applications, CDN (Content Distribution Networks) and P2P (Peer-to-Peer) content distribution technologies have gradually matured. How to effectively use Internet resources thus has attracted more and more attentions. For the study of resource pricing, a whole pricing strategy containing pricing models, mechanisms and methods covers all the related topics. We first introduce three basic Internet resource pricing models through an Internet cost analysis. Then, with the evolution of service types, we introduce several corresponding mechanisms which can ensure pricing implementation and resource allocation. On network resource pricing methods, we discuss the utility optimization in economics, and emphasize two classes of pricing methods (including system optimization and entities' strategic optimizations). Finally, we conclude the paper and forecast the research direction on pricing strategy which is applicable to novel service situation in the near future.

He, Huan; Liu, Ying

2011-01-01T23:59:59.000Z

179

Classification of coal images by a multi-scale segmentation techniques  

Science Conference Proceedings (OSTI)

This paper describes development of an automated and efficient technique for classifying different major maceral groups within polished coal blocks. Coal utilisation processes can be significantly affected by the distribution of macerals in the feed ... Keywords: coal images classification, computational complexity, image classification, image segmentation, maceral groups, multi-scale segmentation techniques, pixel values, polished coal blocks, probability, statistical model, transition distribution

1995-11-01T23:59:59.000Z

180

Multiscale Organization of Convection Simulated with Explicit Cloud Processes on an Aquaplanet  

Science Conference Proceedings (OSTI)

This study investigated the multiscale organization of tropical convection on an aquaplanet in a model experiment with a horizontal mesh size of 3.5 km (for a 10-day simulation) and 7 km (for a 40-day simulation). The numerical experiment used ...

Tomoe Nasuno; Hirofumi Tomita; Shinichi Iga; Hiroaki Miura; Masaki Satoh

2007-06-01T23:59:59.000Z

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181

MULTISCALE DISCRETIZATION OF SHAPE CONTOURS  

SciTech Connect

We present an efficient multi-scale scheme to adaptively approximate the continuous (or densely sampled) contour of a planar shape at varying resolutions. The notion of shape is intimately related to the notion of contour, and the efficient representation of the contour of a shape is vital to a computational understanding of the shape. Any polygonal approximation of a planar smooth curve is equivalent to a piecewise constant approximation of the parameterized X and Y coordinate functions of a discrete point set obtained by densely sampling the curve. Using the Haar wavelet transform for the piecewise approximation yields a hierarchical scheme in which the size of the approximating point set is traded off against the morphological accuracy of the approximation. Our algorithm compresses the representation of the initial shape contour to a sparse sequence of points in the plane defining the vertices of the shape's polygonal approximation. Furthermore, it is possible to control the overall resolution of the approximation by a single, scale-independent parameter.

Prasad, L.; Rao, R.

2000-09-01T23:59:59.000Z

182

Alternative methods of modeling wind generation using production costing models  

DOE Green Energy (OSTI)

This paper examines the methods of incorporating wind generation in two production costing models: one is a load duration curve (LDC) based model and the other is a chronological-based model. These two models were used to evaluate the impacts of wind generation on two utility systems using actual collected wind data at two locations with high potential for wind generation. The results are sensitive to the selected wind data and the level of benefits of wind generation is sensitive to the load forecast. The total production cost over a year obtained by the chronological approach does not differ significantly from that of the LDC approach, though the chronological commitment of units is more realistic and more accurate. Chronological models provide the capability of answering important questions about wind resources which are difficult or impossible to address with LDC models.

Milligan, M.R. [National Renewable Energy Lab., Golden, CO (United States); Pang, C.K. [P Plus Corp., Cupertino, CA (United States)

1996-08-01T23:59:59.000Z

183

Science based integrated approach to advanced nuclear fuel development - integrated multi-scale multi-physics hierarchical modeling and simulation framework Part III: cladding  

Science Conference Proceedings (OSTI)

Advancing the performance of Light Water Reactors, Advanced Nuclear Fuel Cycles, and Advanced Reactors, such as the Next Generation Nuclear Power Plants, requires enhancing our fundamental understanding of fuel and materials behavior under irradiation. The capability to accurately model the nuclear fuel systems to develop predictive tools is critical. Not only are fabrication and performance models needed to understand specific aspects of the nuclear fuel, fully coupled fuel simulation codes are required to achieve licensing of specific nuclear fuel designs for operation. The backbone of these codes, models, and simulations is a fundamental understanding and predictive capability for simulating the phase and microstructural behavior of the nuclear fuel system materials and matrices. In this paper we review the current status of the advanced modeling and simulation of nuclear reactor cladding, with emphasis on what is available and what is to be developed in each scale of the project, how we propose to pass information from one scale to the next, and what experimental information is required for benchmarking and advancing the modeling at each scale level.

Tome, Carlos N [Los Alamos National Laboratory; Caro, J A [Los Alamos National Laboratory; Lebensohn, R A [Los Alamos National Laboratory; Unal, Cetin [Los Alamos National Laboratory; Arsenlis, A [LLNL; Marian, J [LLNL; Pasamehmetoglu, K [INL

2010-01-01T23:59:59.000Z

184

A multi-scale biophysical model to inform regional management of coral reefs in the western Philippines and South China Sea  

Science Conference Proceedings (OSTI)

The health and functioning of coral reef ecosystems worldwide is in decline, and in the face of increasing anthropogenic stress, the rate of decline of these important ecosystems is set to accelerate. Mitigation strategies at regional scales are costly, ... Keywords: CORSET, Connectivity, Coral reef, Decision support, Ecosystem model, Management, Philippines, Regional scale, South China Sea

J. Melbourne-Thomas; C. R. Johnson; P. M. Aliño; R. C. Geronimo; C. L. Villanoy; G. G. Gurney

2011-01-01T23:59:59.000Z

185

Collaboratory for Multiscale Chemical Science (CMCS)  

SciTech Connect

This document provides details of the contributions made by NIST to the Collaboratory for Multiscale Chemical Science (CMCS) project. In particular, efforts related to the provision of data (and software in support of that data) relevant to the combustion pilot project are described.

Allison, Thomas C [NIST

2012-07-03T23:59:59.000Z

186

A Study of the Iceland–Faeroe Frontal Variability Using the Multiscale Energy and Vorticity Analysis  

Science Conference Proceedings (OSTI)

The multiscale nonlinear interactive Iceland–Faeroe frontal (IFF) variability during 14–22 August 1993 is investigated for complex dynamics with the localized multiscale energy and vorticity analysis (MS-EVA). In terms of multiscale window ...

Xiang San Liang; Allan R. Robinson

2004-12-01T23:59:59.000Z

187

Multiscale Simulation of Thermo-mechanical Processes in Irradiated Fission-reactor Materials  

SciTech Connect

This report contains a summary of progress made on the subtask area on phase field model development for microstructure evolution in irradiated materials, which was a part of the Computational Materials Science Network (CMSN) project entitled: Multiscale Simulation of Thermo-mechanical Processes in Irradiated Fission-reactor Materials. The model problem chosen has been that of void nucleation and growth under irradiation conditions in single component systems.

Anter El-Azab

2012-05-28T23:59:59.000Z

188

Multi-scale, Multi-physics Optimization Framework for Additively ...  

Science Conference Proceedings (OSTI)

On-Site Speaker (Planned), Tahany El-Wardany. Abstract Scope, This paper proposes an optimization framework that enables the integration of multi-scale ...

189

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections...  

Open Energy Info (EERE)

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie Valley-Central Nevada Seismic Belt Area- Implications from Mt Resistivity Surveying Jump to: navigation,...

190

Master Thesis Proposals Multiscale Techniques for the Optimal Control of PDEs with Application to the Design of Catalysts  

E-Print Network (OSTI)

Chemical catalysts are essential for the fast and selective transformation of raw materials to end products such as in the production of gasoline, diesel and plastics from crude oil. Discovery of more efficient catalysts therefore has a large economical impact. In this thesis we aim at contributing to this research by developing fast and robust mathematical optimization techniques The transport of chemical species through a catalyst is modeled by a system of coupled reaction-diffusion equations [3]. Solving these systems via numerical techniques remains to date a computationally challenging task. The straightforward inclusion of these modeling tools in optimization procedures is therefore prohibitevily expensive. In this thesis we therefore aim at exploiting previously developed expertise in multiscale optimization techniques to the catalyst design problem and to apply space-mapping techniques [2]. The idea here is to consider the PDEs model as a accurate (fine) model and to complement this model with a computationally cheap (coarse) model. A mapping between the models allows to shift the optimization to the coarse model and to correct this model when needed by using the fine model. This approach is expected to result in a considerable speedup of the overall optimization procedure. In parallel to the application of space-mapping techniques, we will also look into the application of adjoint equation methods to compute the sensitivity of the cost function [1]. It is expected that information on the gradient of the cost function will again allow to speed up the optimization procedure.

D. Lahaye; Biological Engineering

2008-01-01T23:59:59.000Z

191

MULTISCALE MODELING OF FLUID TRANSPORT IN ...  

Science Conference Proceedings (OSTI)

... ACKNOWLEDGEMENTS Fontainebleau sandstone images were prepared by John Dunsmuir of Exxon Re- search & Engineering Co. ...

2010-12-15T23:59:59.000Z

192

Multiscale modeling of fluid transport in heterogeneous ...  

Science Conference Proceedings (OSTI)

... ACKNOWLEDGEMENTS Fontainebleau sandstone images were prepared by John Dunsmuir of Exxon Research & Engneering Co. ...

2003-03-14T23:59:59.000Z

193

Conclusions - Multiscale modeling of fluid transport in ...  

Science Conference Proceedings (OSTI)

... ACKNOWLEDGEMENTS. Fontainebleau sandstone images were prepared by John Dunsmuir of Exxon Research & Engineering Co. ...

2003-11-06T23:59:59.000Z

194

Modeling and Experimental Validation of Multiscale Mechanical ...  

Science Conference Proceedings (OSTI)

Jul 31, 2012 ... Jonathan Zimmerman, Sandia National Laboratories. Scope, The mechanical behavior of a material has a strong and complex connection to its ...

195

Modeling and Experimental Validation of Multiscale Mechanical ...  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Program Organizers: Nathan Mara, Los Alamos National Laboratory; ..... of Energy's National Nuclear Security Administration under contract ...

196

Multiscale Modeling of Radiation Damage in  

E-Print Network (OSTI)

- Up 40% @ 0.025 dpa (HFIR neutrons) additional T trapping sites in material bulk - He induced W "fuzz

197

MULTISCALE MODELING OF FLUID TRANSPORT IN ...  

Science Conference Proceedings (OSTI)

... distinguish between pore (black) and solid (white). ... the National Synchrotron Light Source, Brookhaven ... presented in this paper originally appeared ...

198

Fatigue in Materials: Fundamentals, Multiscale Modeling and ...  

Science Conference Proceedings (OSTI)

Organizer(s), Antonios Kontsos, Drexel University Tongguang Zhai, University of Kentucky. Scope, This symposium features new discoveries and significant ...

199

References - Multiscale modeling of fluid transport in ...  

Science Conference Proceedings (OSTI)

... [13] T. Bourbie and B. Zinszner, "Hydraulic and Acoustic Properties as ... [15] EN Landis and DT Keane, "X-ray microtomography for fracture studies in ...

2003-11-06T23:59:59.000Z

200

Restoring images with a multiscale neural network based technique  

Science Conference Proceedings (OSTI)

This paper describes a neural network based multiscale image restoration approach in which multilayer perceptrons are trained with artificial images of degraded gray level cocentered circles. The main objective of this approach is to make the neural ... Keywords: artificial neural network, image restoration, multiscale

Ana Paula Abrantes de Castro; José Demisio Simões da Silva

2008-03-01T23:59:59.000Z

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


201

Metadata in the collaboratory for multi-scale chemical science  

Science Conference Proceedings (OSTI)

The goal of the Collaboratory for the Multi-scale Chemical Sciences (CMCS) [1] is to develop an informatics-based approach to synthesizing multi-scale chemistry information to create knowledge in the chemical sciences. CMCS is using a portal and metadata-aware ... Keywords: Dublin Core, WebDAV, chemistry, collaboratory, knowledge management, metadata

Carmen Pancerella; John Hewson; Wendy Koegler; David Leahy; Michael Lee; Larry Rahn; Christine Yang; James D. Myers; Brett Didier; Renata McCoy; Karen Schuchardt; Eric Stephan; Theresa Windus; Kaizar Amin; Sandra Bittner; Carina Lansing; Michael Minkoff; Sandeep Nijsure; Gregor von Laszewski; Reinhardt Pinzon; Branko Ruscic; Al Wagner; Baoshan Wang; William Pitz; Yen-Ling Ho; David Montoya; Lili Xu; Thomas C. Allison; William H. Green, Jr.; Michael Frenklach

2003-09-01T23:59:59.000Z

202

Asymptotic analysis of multiscale approximations to reaction networks  

E-Print Network (OSTI)

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

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

1961-01-01T23:59:59.000Z

203

Pultrusion manufacturing process development by computational modelling and methods  

Science Conference Proceedings (OSTI)

This paper deals with the modelling and development of computational schemes to simulate pultrusion processes. Two different computational methods, finite differences and elements, are properly developed and critically analyzed. The methods are applied ... Keywords: Degree of cure, Finite difference method, Finite element method, Numerical modelling, Pultrusion, Temperature

P. Carlone; G. S. Palazzo; R. Pasquino

2006-10-01T23:59:59.000Z

204

Multi-scale Simulation Methodology for Stress Assessment in 3D IC: Effect of Die Stacking on Device Performance  

Science Conference Proceedings (OSTI)

Potential challenges with managing mechanical stress distributions and the consequent effects on device performance for advanced 3D integrated circuit (IC) technologies are outlined. A set of physics-based compact models for a multi-scale simulation, ... Keywords: 3D IC, FEA, Layout, Packaging, Strain engineering, Stress, TSV

Valeriy Sukharev; Armen Kteyan; Jun-Ho Choy; Henrik Hovsepyan; Ara Markosian; Ehrenfried Zschech; Rene Huebner

2012-02-01T23:59:59.000Z

205

Multiscale FEM-MD schema  

Science Conference Proceedings (OSTI)

... coupling finite element modeling (FEM) to atomistic Molecular Dynamics (MD) 1 ... for using extremely high (very unrealistic) indentation rates that are ...

2013-06-27T23:59:59.000Z

206

Localized Scale Coupling and New Educational Paradigms in Multiscale Mathematics and Science  

SciTech Connect

One of the most challenging multi-scale simulation problems in the area of multi-phase materials is to develop effective computational techniques for the prediction of coalescence and related phenomena involving rupture of a thin liquid film due to the onset of instability driven by van der Waals or other micro-scale attractive forces. Accurate modeling of this process is critical to prediction of the outcome of milling processes for immiscible polymer blends, one of the most important routes to new advanced polymeric materials. In typical situations, the blend evolves into an ?emulsion? of dispersed phase drops in a continuous matrix fluid. Coalescence is then a critical factor in determining the size distribution of the dispersed phase, but is extremely difficult to predict from first principles. The thin film separating two drops may only achieve rupture at dimensions of approximately 10 nm while the drop sizes are 0(10 ?m). It is essential to achieve very accurate solutions for the flow and for the interface shape at both the macroscale of the full drops, and within the thin film (where the destabilizing disjoining pressure due to van der Waals forces is proportional approximately to the inverse third power of the local film thickness, h-3). Furthermore, the fluids of interest are polymeric (through Newtonian) and the classical continuum description begins to fail as the film thins ? requiring incorporation of molecular effects, such as a hybrid code that incorporates a version of coarse grain molecular dynamics within the thin film coupled with a classical continuum description elsewhere in the flow domain. Finally, the presence of surface active additions, either surfactants (in the form of di-block copolymers) or surface-functionalized micro- or nano-scale particles, adds an additional level of complexity, requiring development of a distinct numerical method to predict the nonuniform concentration gradients of these additives that are responsible for Marangoni stresses at the interface. Again, the physical dimensions of these additives may become comparable to the thin film dimensions, requiring an additional layer of multi-scale modeling.

LEAL, L. GARY

2013-06-30T23:59:59.000Z

207

Phase-Field-Crystal Modeling for Crack Propagation of Ductile ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The phase-field-crystal method is a new multiscale method, ... of Microstructure-Tensile Properties Correlations in Beta-Processed Ti-5111 Alloy.

208

Predicting Thermal Conductivity Evolution of Polycrystalline Materials Under Irradiation Using Multiscale Approach  

SciTech Connect

A multiscale methodology was developed to predict the evolution of thermal conductivity of polycrystalline fuel under irradiation. In the mesoscale level, phase field model was used to predict the evolution of gas bubble microstructure. Generation of gas atoms and vacancies were taken into consideration. In the macroscopic scale, a statistical continuum mechanics model was applied to predict the anisotropic thermal conductivity evolution during irradiation. Microstructure predicted by phase field model was fed into statistical continuum mechanics model to predict properties and behavior. Influence of irradiation intensity, exposition time and morphology were investigated. This approach provides a deep understanding on microstructure evolution and property prediction from a basic scientific viewpoint.

Li, Dongsheng; Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.

2012-03-01T23:59:59.000Z

209

A Model-Based Method For Building Reconstruction  

Science Conference Proceedings (OSTI)

In this paper model-based reconstruction methods are applied to the detailed reconstruction of buildings from close-range images. The 3D points obtained through image matching are segmented into a coarse polyhedral model with a robust regression ...

Konrad Schindler; Joachim Bauer

2003-10-01T23:59:59.000Z

210

On Scalar and Vector Transform Methods for Global Spectral Models  

Science Conference Proceedings (OSTI)

We compare scalare and vector transform methods for global spectral models of the shallow-water equations. For the scalar transform methods, we demonstrate some economies in the number of Legendre transforms required. It is shown that the ...

Clive Temperton

1991-05-01T23:59:59.000Z

211

Multiscale Large Eddy States in Weakly Stratified Planetary Boundary Layers  

Science Conference Proceedings (OSTI)

We first discuss observations of two classes of two-dimensional large eddy states in weakly stratified atmospheric boundary layers. One class is characterized by large eddies with a single horizontal scale. The other contains multiscale large ...

Pierre D. Mourad; Robert A. Brown

1990-02-01T23:59:59.000Z

212

Multiscale Low-Frequency Circulation Modes in the Global Atmosphere  

Science Conference Proceedings (OSTI)

In this paper, fundamental multiscale circulation modes in the global atmosphere are identified with the objective of providing better understanding of atmospheric low-frequency variabilities over a wide range of spatial and temporal scales. With ...

K-M. Lau; P-J. Sheu; I-S. Kang

1994-05-01T23:59:59.000Z

213

Modeling and Forecasting Aurora  

Science Conference Proceedings (OSTI)

Modeling the physical processes needed for forecasting space-weather events requires multiscale modeling. This article discusses several modelsresearchers use to treat the various auroral processes that influence space weather.

Dirk Lummerzheim

2007-01-01T23:59:59.000Z

214

Market Mill Dependence Pattern in the Stock Market: Multiscale Conditional Dynamics  

E-Print Network (OSTI)

Market Mill is a complex dependence pattern leading to nonlinear correlations and predictability in intraday dynamics of stock prices. The present paper puts together previous efforts to build a dynamical model reflecting the market mill asymmetries. We show that certain properties of the conditional dynamics at a single time scale result in the "elementary" market mill pattern. We discuss these properties as a mixture of trend-preserving and contrarian strategies used by market agents. Multiple time scale considerations make the resulting "composite" mill similar to the empirical market mill patterns. Multiscale model also reflects a multi-agent nature of the market.

Zaitsev, Sergey; Leonidov, Andrei; Trainin, Vladimir

2008-01-01T23:59:59.000Z

215

Computation of Thermal Fields with Non-Stationary Model at ...  

Science Conference Proceedings (OSTI)

Numerical experiments in the case of electron beam melting of different metals ... Multiscale Modeling of Nanoscale Precipitate Stability in Irradiated Materials.

216

Validation of Models and Simulations of Nuclear Fuels  

Science Conference Proceedings (OSTI)

Symposium, Characterization of Nuclear Reactor Materials and Components with ... Multi-scale theoretical models and computer simulations are often used to ...

217

A Marker Chain Front Tracking Method for Modelling Meniscus ...  

Science Conference Proceedings (OSTI)

Feb 1, 2002 ... A Marker Chain Front Tracking Method for Modelling Meniscus Dynamics in the Al Ingot Casting Process by F. Iversen, J.A. Bakken and S.T. ...

218

Application of the Piecewise Parabolic Method (PPM) to Meteorological Modeling  

Science Conference Proceedings (OSTI)

The Piecewise Parabolic Method (PPM), a numerical technique developed in astrophysics for modeling fluid flows with strong shocks and discontinuities is adapted for treating sharp gradients in small-scale meteorological flows. PPM differs ...

Richard L. Carpenter Jr.; Kelvin K. Droegemeier; Paul R. Woodward; Carl E. Hane

1990-03-01T23:59:59.000Z

219

Multiscale Simulation of Quantum Nanosystems: Plasmonics of Silver Particles  

E-Print Network (OSTI)

Quantum nanosystems involve the coupled dynamics of fermions or bosons across multiple scales in space and time. Examples include quantum dots, superconducting or magnetic nanoparticles, molecular wires, and graphene nanoribbons. The number (10^3 to 10^9) of electrons in assemblies of interest here presents a challenge for traditional quantum computations. However, results from deductive multiscale analysis yield coarse-grained wave equation that capture the longer-scale quantum dynamics of these systems; a companion short-scale equation is also developed that allows for the construction of effective masses and interactions involved in the coarse-grained wave equation. The theory suggest an efficient algorithm for simulating quantum nanosystem which is implemented here. A variational Monte Carlo method is used to simulate the co-evolution of long- and short-scale processes. The approach does not require experimental data for calibration. It is validated via experimental data and TDDFT predictions on the nanoparticle size dependence of the plasmon spectrum.

D. Balamurugan; Peter. J. Ortoleva

2011-10-31T23:59:59.000Z

220

Meta methods for model sharing in personal information systems  

Science Conference Proceedings (OSTI)

This article introduces a methodology for automatically organizing document collections into thematic categories for Personal Information Management (PIM) through collaborative sharing of machine learning models in an efficient and privacy-preserving ... Keywords: Classification, clustering, meta methods, peer-to-peer, personal information management, restrictive methods

Stefan Siersdorfer; Sergej Sizov

2008-09-01T23:59:59.000Z

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


221

Collocation Methods for Distillation Design I: Model Description and Testing  

E-Print Network (OSTI)

Fast and accurate distillation design requires a model that significantly reduces the problem size while accurately approximating a full order distillation column model. Variable number of trays and variable feed tray location make optimization possible. This collocation model builds on the concepts of past collocation models for design of complex real-world separation systems. Two variable transformations make this method unique. Polynomials cannot accurately fit trajectories which flatten out. In columns, flat sections occur in the middle of large column sections, or where concentrations go to zero or one. With an exponential transformation of the tray number which maps zero to an infinite number of trays onto the range zero to one, two collocation trays can accurately simulate a large column section. With a hyperbolic tangent transformation of the mole fractions, the model can simulate columns which reach high purities. Furthermore, this model uses multiple collocation elements for ...

Robert S. Huss; Arthur W. Westerberg

1995-01-01T23:59:59.000Z

222

Structural Materials Modeling  

Science Conference Proceedings (OSTI)

Mar 5, 2013 ... Sponsored by: TMS Materials Processing and Manufacturing Division, TMS ... Fei Gao2; Kiran Solanki3; Xin Sun2; 1Mississippi State University; 2PNNL; ... A Multiscale Metal/Hydride Mechanical Model for Used-Fuel Zircaloy ...

223

Statistical Methods for Combining Measurements and Models, with Application  

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

Statistical Methods for Combining Measurements and Models, with Application Statistical Methods for Combining Measurements and Models, with Application to Mapping Particulate Matter Speaker(s): Chris Paciorek Date: February 11, 2011 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Michael Sohn Modern statistical methods, in particular Bayesian hierarchical models, provide a framework for combining various types of measurements in a single analysis. I'll describe a basic latent variable framework for dealing with spatial and spatio-temporal data. The approach is to represent the spatial and spatio-temporal field of interest as a latent field and relate observations to that field. An observation may represent a single point in space and time or an average over space and time. Then I'll describe how to use the approach to combine measurements with proxies such as computer code

224

Modeling biofilm processes using the immersed boundary method  

SciTech Connect

Biofilm processes are of interest to researchers in a variety of fields including bioremediation, oil recovery, waste water treatment, medicine, and dentistry. In this paper we describe how this complex, dynamic, fluid-structure interaction can be modeled successfully using the immersed boundary method. The model presented here includes the coupling of hydrodynamics; substrate reaction, diffusion, and convection; as well as the chemotactic response of swimming microbes. Cell-cell aggregation and cell-substratum adhesion are modeled by generating appropriate binding forces between discrete representations of organisms that may hold them together, or if fluid stresses are large, may yield and release the organisms. In this paper, we show two-dimensional numerical simulations to demonstrate several different types of scenarios that may be modeled using immersed boundary methods. These simulations indicate the variety of different phenomena one might expect in biofilm processes. 24 refs., 8 figs., 2 tabs.

Dillon, R.; Fauci, L. [Tulane Univ., New Orleans, LA (United States); Fogelson, A. [Univ. of Utah, Salt Lake City, UT (United States)] [and others

1996-11-01T23:59:59.000Z

225

DES modelling and control vs. problem solving methods  

Science Conference Proceedings (OSTI)

Modelling and control of a kind of Discrete-Event Systems (DES) having a character of Flexible Manufacturing Systems (FMS) are examined by means of methods used in applied artificial intelligence. While assembly and/or disassembly ... Keywords: DES modelling, FMS control, PNs, Petri nets, agent-based systems, artificial intelligence, control agents, decision making, discrete event systems, flexible manufacturing systems, intelligent information, multi-agent systems, ontology, problem solving, reachability graphs, vehicle crossroads

Frantisek Capkovic

2007-04-01T23:59:59.000Z

226

Hybrid atomistic-continuum method for the simulation of dense fluid flows  

Science Conference Proceedings (OSTI)

We present a hybrid atomistic-continuum method for multiscale simulations of dense fluids. In this method, the atomistic part is described using a molecular dynamics description, while the continuum flow is described by a finite volume discretization ... Keywords: Hybrid algorithms, Molecular dynamics, Multiscale simulation, Nanofluidics

Thomas Werder; Jens H. Walther; Petros Koumoutsakos

2005-05-01T23:59:59.000Z

227

Bayesian methods for discontinuity detection in climate model predictions.  

Science Conference Proceedings (OSTI)

Discontinuity detection is an important component in many fields: Image recognition, Digital signal processing, and Climate change research. Current methods shortcomings are: Restricted to one- or two-dimensional setting, Require uniformly spaced and/or dense input data, and Give deterministic answers without quantifying the uncertainty. Spectral methods for Uncertainty Quantification with global, smooth bases are challenged by discontinuities in model simulation results. Domain decomposition reduces the impact of nonlinearities and discontinuities. However, while gaining more smoothness in each subdomain, the current domain refinement methods require prohibitively many simulations. Therefore, detecting discontinuities up front and refining accordingly provides huge improvement to the current methodologies.

Safta, Cosmin; Debusschere, Bert J.; Najm, Habib N.; Sargsyan, Khachik

2010-06-01T23:59:59.000Z

228

Modeling of switching operations using fault matrix method  

Science Conference Proceedings (OSTI)

Switching operations in energy supply networks are either modeled by adding or removing artificial nodes which results in state dependent grid topology or by setting the switch impedance to high or low value. This procedure is not very accurate and can ... Keywords: admittance matrix, fault matrix method, power system, switching operation, transmission lines

Martin Wolter; Bernd R. Oswald

2007-05-01T23:59:59.000Z

229

Detection of illicit traffic based on multiscale analysis  

Science Conference Proceedings (OSTI)

Recent years have witnessed a huge increase in the number and variety of Internet applications, as well as on the number and diversity of security attacks to network users and systems. Consequently, the need for an accurate mapping of traffic to its ... Keywords: application identification, cluster analysis, licit and illict applications, multifractal behavior, multiscale analysis, wavelets

Eduardo Rocha; Paulo Salvador; António Nogueira

2009-09-01T23:59:59.000Z

230

Avalanches through windows: Multiscale visualization in magnetic thin films  

E-Print Network (OSTI)

Avalanches through windows: Multiscale visualization in magnetic thin films Alessandro Magni dynamics, but are strongly dependent on the size of the windows chosen. Here we investigate how to properly sub-window of the entire sample. Usually, windows of varying sizes are used, and the distributions

Sethna, James P.

231

Multi-Scale Initial Conditions For Cosmological Simulations  

SciTech Connect

We discuss a new algorithm to generate multi-scale initial conditions with multiple levels of refinements for cosmological 'zoom-in' simulations. The method uses an adaptive convolution of Gaussian white noise with a real-space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first- (1LPT) or second-order Lagrangian perturbation theory (2LPT). The new algorithm achieves rms relative errors of the order of 10{sup -4} for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier-space-induced interference ringing. An optional hybrid multi-grid and Fast Fourier Transform (FFT) based scheme is introduced which has identical Fourier-space behaviour as traditional approaches. Using a suite of re-simulations of a galaxy cluster halo our real-space-based approach is found to reproduce correlation functions, density profiles, key halo properties and subhalo abundances with per cent level accuracy. Finally, we generalize our approach for two-component baryon and dark-matter simulations and demonstrate that the power spectrum evolution is in excellent agreement with linear perturbation theory. For initial baryon density fields, it is suggested to use the local Lagrangian approximation in order to generate a density field for mesh-based codes that is consistent with the Lagrangian perturbation theory instead of the current practice of using the Eulerian linearly scaled densities.

Hahn, Oliver; /KIPAC, Menlo Park; Abel, Tom; /KIPAC, Menlo Park /ZAH, Heidelberg /HITS, Heidelberg

2011-11-04T23:59:59.000Z

232

Alternative wind power modeling methods using chronological and load duration curve production cost models  

DOE Green Energy (OSTI)

As an intermittent resource, capturing the temporal variation in windpower is an important issue in the context of utility production cost modeling. Many of the production cost models use a method that creates a cumulative probability distribution that is outside the time domain. The purpose of this report is to examine two production cost models that represent the two major model types: chronological and load duration cure models. This report is part of the ongoing research undertaken by the Wind Technology Division of the National Renewable Energy Laboratory in utility modeling and wind system integration.

Milligan, M R

1996-04-01T23:59:59.000Z

233

HyPEP FY06 Report: Models and Methods  

DOE Green Energy (OSTI)

The Department of Energy envisions the next generation very high-temperature gas-cooled reactor (VHTR) as a single-purpose or dual-purpose facility that produces hydrogen and electricity. The Ministry of Science and Technology (MOST) of the Republic of Korea also selected VHTR for the Nuclear Hydrogen Development and Demonstration (NHDD) Project. This research project aims at developing a user-friendly program for evaluating and optimizing cycle efficiencies of producing hydrogen and electricity in a Very-High-Temperature Reactor (VHTR). Systems for producing electricity and hydrogen are complex and the calculations associated with optimizing these systems are intensive, involving a large number of operating parameter variations and many different system configurations. This research project will produce the HyPEP computer model, which is specifically designed to be an easy-to-use and fast running tool for evaluating nuclear hydrogen and electricity production facilities. The model accommodates flexible system layouts and its cost models will enable HyPEP to be well-suited for system optimization. Specific activities of this research are designed to develop the HyPEP model into a working tool, including (a) identifying major systems and components for modeling, (b) establishing system operating parameters and calculation scope, (c) establishing the overall calculation scheme, (d) developing component models, (e) developing cost and optimization models, and (f) verifying and validating the program. Once the HyPEP model is fully developed and validated, it will be used to execute calculations on candidate system configurations. FY-06 report includes a description of reference designs, methods used in this study, models and computational strategies developed for the first year effort. Results from computer codes such as HYSYS and GASS/PASS-H used by Idaho National Laboratory and Argonne National Laboratory, respectively will be benchmarked with HyPEP results in the following years.

DOE report

2006-09-01T23:59:59.000Z

234

Back analysis of microplane model parameters using soft computing methods  

E-Print Network (OSTI)

A new procedure based on layered feed-forward neural networks for the microplane material model parameters identification is proposed in the present paper. Novelties are usage of the Latin Hypercube Sampling method for the generation of training sets, a systematic employment of stochastic sensitivity analysis and a genetic algorithm-based training of a neural network by an evolutionary algorithm. Advantages and disadvantages of this approach together with possible extensions are thoroughly discussed and analyzed.

Kucerova, A; Zeman, J

2009-01-01T23:59:59.000Z

235

Assessment of Molecular Modeling & Simulation  

Science Conference Proceedings (OSTI)

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.

None

2002-01-03T23:59:59.000Z

236

A Method for Adaptive Habit Prediction in Bulk Microphysical Models. Part II: Parcel Model Corroboration  

Science Conference Proceedings (OSTI)

It is common for cloud microphysical models to use a single axis length to characterize ice crystals. These methods use either the diameter of an equivalent sphere or mass–size equations in conjunction with the capacitance model to close the ...

Jerry Y. Harrington; Kara Sulia; Hugh Morrison

2013-02-01T23:59:59.000Z

237

?-Method: a model-driven formal method for architecture-centric software engineering  

Science Conference Proceedings (OSTI)

Software systems have become increasingly complex and are often used in highly dynamic, distributed and mobile environments. Formal development of such software systems in order to guarantee their completeness and correctness is a large research challenge. ... Keywords: architecture analysis languages, architecture description languages, architecture transformation/refinement languages, architecture-centric software engineering, component-based software engineering, formal methods, model-driven development, software architectures

Flavio Oquendo

2006-05-01T23:59:59.000Z

238

Multiscale Toxicology- Building the Next Generation Tools for Toxicology  

SciTech Connect

A Cooperative Research and Development Agreement (CRADA) was established between Battelle Memorial Institute (BMI), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), Brookhaven National Laboratory (BNL), Lawrence Livermore National Laboratory (LLNL) with the goal of combining the analytical and synthetic strengths of the National Laboratories with BMI?s expertise in basic and translational medical research to develop a collaborative pipeline and suite of high throughput and imaging technologies that could be used to provide a more comprehensive understanding of material and drug toxicology in humans. The Multi-Scale Toxicity Initiative (MSTI), consisting of the team members above, was established to coordinate cellular scale, high-throughput in vitro testing, computational modeling and whole animal in vivo toxicology studies between MSTI team members. Development of a common, well-characterized set of materials for testing was identified as a crucial need for the initiative. Two research tracks were established by BMI during the course of the CRADA. The first research track focused on the development of tools and techniques for understanding the toxicity of nanomaterials, specifically inorganic nanoparticles (NPs). ORNL?s work focused primarily on the synthesis, functionalization and characterization of a common set of NPs for dissemination to the participating laboratories. These particles were synthesized to retain the same surface characteristics and size, but to allow visualization using the variety of imaging technologies present across the team. Characterization included the quantitative analysis of physical and chemical properties of the materials as well as the preliminary assessment of NP toxicity using commercially available toxicity screens and emerging optical imaging strategies. Additional efforts examined the development of high-throughput microfluidic and imaging assays for measuring NP uptake, localization, and toxicity in vitro. The second research track within the MSTI CRADA focused on the development of ex vivo animal models for examining druginduced cardiotoxicity. ORNL's role in the second track was limited initially, but was later expanded to include the development of microfluidic platforms that might facilitate the translation of Cardiac 'Microwire' technologies developed at the University of Toronto into a functional platform for drug screening and predictive assessment of cardiotoxicity via highthroughput measurements of contractility. This work was coordinated by BMI with the Centre for the Commercialization of Regenerative Medicine (CCRM) and the University of Toronto (U Toronto). This partnership was expanded and culminated in the submission of proposal to Work for Others (WFO) agencies to explore the development of a broader set of microphysiological systems, a so call human-on-a-chip, that could be used for toxicity screening and the evaluation of bio-threat countermeasures.

Retterer, S. T. [ORNL] [ORNL; Holsapple, M. P. [Battelle Memorial Institute] [Battelle Memorial Institute

2013-10-31T23:59:59.000Z

239

Multiband segmentation based on a hierarchical Markov model  

Science Conference Proceedings (OSTI)

We develop a new multiscale Markov segmentation model for multiband images. Using quadtree multiple resolution analysis of a multiband image, we use both inter- and intra-scale spatial Markov statistical dependencies. Bayesian inference is used to assess ... Keywords: Bayes factor, Bayes information criterion, Bayesian inference, Generalized Gaussian distribution, Markov random field, Multiband image, Multiresolution, Multiscale, Multispectral image, Quadtree

Christophe Collet; Fionn Murtagh

2004-12-01T23:59:59.000Z

240

Lifetime statistics of quantum chaos studied by a multiscale analysis  

SciTech Connect

In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.

Di Falco, A.; Krauss, T. F. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, KY16 9SS (United Kingdom); Fratalocchi, A. [PRIMALIGHT, Faculty of Electrical Engineering, Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)

2012-04-30T23:59:59.000Z

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


241

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes  

Science Conference Proceedings (OSTI)

This project is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

Yortsos, Yanis C.

2001-08-07T23:59:59.000Z

242

Usability tests for improvement of 3D navigation in multiscale environments  

Science Conference Proceedings (OSTI)

The interest in virtual 3D environments has increased in the past years due to the popularization of the technology and the huge human ability to visually convey and grasp information. However, unlike the real world, 3D navigation, especially in multiscale ... Keywords: 3D navigation, cubemap, multiscale environments, usability

Tathiane Mendonça Andrade; Daniel Ribeiro Trindade; Eduardo Ribeiro Silva; Alberto Barbosa Raposo; Simone Diniz Junqueira Barbosa

2011-07-01T23:59:59.000Z

243

Optimal Multi-scale Capacity Planning under Hourly Varying Electricity Prices  

E-Print Network (OSTI)

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

Grossmann, Ignacio E.

244

Oil Price Forecasting with an EMD-Based Multiscale Neural Network Learning Paradigm  

Science Conference Proceedings (OSTI)

In this study, a multiscale neural network learning paradigm based on empirical mode decomposition (EMD) is proposed for crude oil price prediction. In this learning paradigm, the original price series are first decomposed into various independent intrinsic ... Keywords: Crude oil price forecasting, artificial neural networks, empirical mode decomposition, multiscale learning paradigm

Lean Yu; Kin Keung Lai; Shouyang Wang; Kaijian He

2007-05-01T23:59:59.000Z

245

Control of multiscale systems with constraints. 1. Basic principles of the concept of evolution of systems with varying constraints  

E-Print Network (OSTI)

Physical fundamentals of the self-organizing theory for the system with varying constraints are considered. A variation principle, specifically the principle of dynamic harmonization as a generalization of the Gauss-Hertz principle for the systems with varying internal structure is formulated. In compliance with this principle the system evolves through dynamics of the processes leading to harmonization of the internal multiscale structure of the system and its connections with external actions as a result of minimizing the dynamic harmonization function. Main principles of the shell model of self-organization under the action of the dominating entropic disturbance are formulated.

S. Adamenko; V. Bolotov; V. Novikov

2013-07-17T23:59:59.000Z

246

An Embedded Boundary Method for the Modelling of Unsteady . . .  

E-Print Network (OSTI)

A new methodology for the modeling of unsteady, nonpremixed, axisymmetric reacting flow in industrial furnaces is presented. The method is an extension of previous work by the authors to complex geometries, multistep kinetics mechanisms, and realistic properties, especially thermochemical data. The walls of the furnace are represented as an embedded boundary in a uniform, rectangular grid. The grid then consists of uniform rectangular cells except at the furnace wall where irregular (mixed) cells may be present. We use finite volume differencing techniques for the convective, viscous, and radiative heat transport terms in the mixed cells, while a finite element-based technique is used to solve the elliptic equation arising from the low-Mach number formulation. Results from the simulation of an experimental natural gas-fired furnace are shown.

Richard B. Pember; Ann S. Almgren; William Y. Crutchfield; Louis H. Howell; John B. Bell; Phillip Colella; Vincent E. Beckner

1995-01-01T23:59:59.000Z

247

A Proposed Method of Developing Air Quality Models for a Limited Wind Fetch  

Science Conference Proceedings (OSTI)

A method is proposed for developing air quality models of a limited wind fetch. The basic model equation is a transient solution to a diffusion equation. This basic model equation is compared to those of the existing models, straightline airflow ...

Edward Y. T. Kuo

1980-02-01T23:59:59.000Z

248

First-principles and Multi-scale  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Modeling porous corrosion deposits (CRUD) in nuclear reactors is a ... Most structural materials are multiphase, where deformation is often ...

249

Three-Dimensional Lithium-Ion Battery Model (Presentation)  

DOE Green Energy (OSTI)

Nonuniform battery physics can cause unexpected performance and life degradations in lithium-ion batteries; a three-dimensional cell performance model was developed by integrating an electrode-scale submodel using a multiscale modeling scheme.

Kim, G. H.; Smith, K.

2008-05-01T23:59:59.000Z

250

The Impact of GEM and MM5 Modeled Meteorological Conditions on CMAQ Air Quality Modeling Results in Eastern Canada and the Northeastern United States  

Science Conference Proceedings (OSTI)

The fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) is currently the meteorological model most widely used as input into the Community Multiscale Air Quality (CMAQ) modeling system. In ...

Steven C. Smyth; Dazhong Yin; Helmut Roth; Weimin Jiang; Michael D. Moran; Louis-Philippe Crevier

2006-11-01T23:59:59.000Z

251

Multiscale CFD simulations of entrained flow gasification  

E-Print Network (OSTI)

The design of entrained flow gasifiers and their operation has largely been an experience based enterprise. Most, if not all, industrial scale gasifiers were designed before it was practical to apply CFD models. Moreover, ...

Kumar, Mayank, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

252

Modeling and prediction of nonlinear environmental system using Bayesian methods  

Science Conference Proceedings (OSTI)

An environmental dynamic system is usually modeled as a nonlinear system described by a set of nonlinear ODEs. A central challenge in computational modeling of environmental systems is the determination of the model parameters. In these cases, estimating ... Keywords: Extended Kalman filter, Leaf area index and soil moisture model, Nonlinear environmental system, Particle filter, State and parameter estimation, Variational filter

Majdi Mansouri; Benjamin Dumont; Marie-France Destain

2013-03-01T23:59:59.000Z

253

Neural node network and model, and method of teaching same  

DOE Patents (OSTI)

The present invention is a fully connected feed forward network that includes at least one hidden layer 16. The hidden layer 16 includes nodes 20 in which the output of the node is fed back to that node as an input with a unit delay produced by a delay device 24 occurring in the feedback path 22 (local feedback). Each node within each layer also receives a delayed output (crosstalk) produced by a delay unit 36 from all the other nodes within the same layer 16. The node performs a transfer function operation based on the inputs from the previous layer and the delayed outputs. The network can be implemented as analog or digital or within a general purpose processor. Two teaching methods can be used: (1) back propagation of weight calculation that includes the local feedback and the crosstalk or (2) more preferably a feed forward gradient decent which immediately follows the output computations and which also includes the local feedback and the crosstalk. Subsequent to the gradient propagation, the weights can be normalized, thereby preventing convergence to a local optimum. Education of the network can be incremental both on and off-line. An educated network is suitable for modeling and controlling dynamic nonlinear systems and time series systems and predicting the outputs as well as hidden states and parameters. The educated network can also be further educated during on-line processing.

Parlos, Alexander G. (College Station, TX); Atiya, Amir F. (College Station, TX); Fernandez, Benito (Austin, TX); Tsai, Wei K. (Irvine, CA); Chong, Kil T. (College Station, TX)

1995-01-01T23:59:59.000Z

254

Neural node network and model, and method of teaching same  

DOE Patents (OSTI)

The present invention is a fully connected feed forward network that includes at least one hidden layer. The hidden layer includes nodes in which the output of the node is fed back to that node as an input with a unit delay produced by a delay device occurring in the feedback path (local feedback). Each node within each layer also receives a delayed output (crosstalk) produced by a delay unit from all the other nodes within the same layer. The node performs a transfer function operation based on the inputs from the previous layer and the delayed outputs. The network can be implemented as analog or digital or within a general purpose processor. Two teaching methods can be used: (1) back propagation of weight calculation that includes the local feedback and the crosstalk or (2) more preferably a feed forward gradient decent which immediately follows the output computations and which also includes the local feedback and the crosstalk. Subsequent to the gradient propagation, the weights can be normalized, thereby preventing convergence to a local optimum. Education of the network can be incremental both on and off-line. An educated network is suitable for modeling and controlling dynamic nonlinear systems and time series systems and predicting the outputs as well as hidden states and parameters. The educated network can also be further educated during on-line processing. 21 figs.

Parlos, A.G.; Atiya, A.F.; Fernandez, B.; Tsai, W.K.; Chong, K.T.

1995-12-26T23:59:59.000Z

255

An importance sampling method for portfolio cvar estimation with Gaussian copula models  

Science Conference Proceedings (OSTI)

We developed an importance sampling method to estimate Conditional Value-at-Risk for portfolios in which inter-dependent asset losses are modeled via a Gaussian copula model. Our method constructs an importance sampling distribution by shifting the latent ...

Pu Huang; Dharmashankar Subramanian; Jie Xu

2010-12-01T23:59:59.000Z

256

Modeling and Test-and-Rate Methods for Innovative Thermosiphon Solar Water Heaters: Preprint  

SciTech Connect

Conference paper regarding research in modeling and test-and-rate methods for thermosiphon solar domestic water heaters.

Burch, J.; Shoukas, G.; Brandemuhl, M.; Krarti, M.

2006-05-01T23:59:59.000Z

257

Convective Precipitation Variability as a Tool for General Circulation Model Analysis  

Science Conference Proceedings (OSTI)

Precipitation variability is analyzed in two versions of the Community Atmospheric Model (CAM), the standard model, CAM, and a “multiscale modeling framework” (MMF), in which the cumulus parameterization has been replaced with a cloud-resolving ...

Charlotte A. DeMott; David A. Randall; Marat Khairoutdinov

2007-01-01T23:59:59.000Z

258

Development and Application of a Multipollutant Model for Atmospheric Mercury Deposition  

Science Conference Proceedings (OSTI)

A multipollutant model, the Community Multiscale Air Quality model paired with the Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (CMAQ-MADRID), is extended to include a comprehensive treatment of mercury processes and is ...

Krish Vijayaraghavan; Christian Seigneur; Prakash Karamchandani; Shu-Yun Chen

2007-09-01T23:59:59.000Z

259

A stochastic multiscale model for electricity generation capacity ...  

E-Print Network (OSTI)

exist in many energy planning problems, in particular load demand uncertainty and uncertainties in generation .... Therefore we only comment on the relations between the analysis here and the literature. In [Jiang ..... Information about long term demand arrives at slower rate. It is not ...... optimization in a pool market. Math.

260

Kinetic Theories in Multiscale Modeling of Polycrystals Maria Emelianenko  

E-Print Network (OSTI)

Resistance Stress Corrosion Cracking Electrical activity Creep Behavior "Insensitive": Average elastic energy

Maryland at College Park, University of

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


261

Multiscale Modeling of Fracture Resistance in TRIP-Assisted ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The fracture resistance of TRIP-assisted multiphase steels is ... austenite in a matrix of ferrite, bainite and martensite in the multiphase steels. ... Statistical Failure Analysis of Crystallographically Isotropic Porous Materials.

262

Multiscale Modeling of Defect Mechanics in Nuclear Materials  

Science Conference Proceedings (OSTI)

Abstract Scope, The key to developing advanced materials for nuclear applications is ... Physics-Based Homogenization of Random Continuum Microstructures.

263

Multiscale Model for Non-metallic Inclusions/Steel Composite ...  

Science Conference Proceedings (OSTI)

It is demonstrated that the data-driven, fully automated protocols developed in this study .... PII-48: Electronic, Structural and Elastic Properties of (V,Nb)Cx.

264

Multiscale modeling and analysis of nanofibers and nonwoven materials  

E-Print Network (OSTI)

Nanostructured fibrous materials have been made more readily available in large part owing to recent advances in electrospinning, which is a technique for the production of nanofibers with diameters down to the range of a ...

Buell, Sezen

2010-01-01T23:59:59.000Z

265

Multiscale computational models of transmural heterogeneities and ventricular arrhythmogenesis  

E-Print Network (OSTI)

sympathetic nervous system (SNS) and the subsequent releasenormal hearts, enhanced SNS activity is thought tothe interface between the SNS and electrophysiology. Other

Flaim, Sarah N.

2006-01-01T23:59:59.000Z

266

Microsoft PowerPoint - Multiscale Modeling_Luo_Tomar  

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

kT g C C ads e X X 1 0 McLean-Langmuir: Fowler-Guggenheim: 0 Fowler 1 ) 0 ( z g g ads ads Reprint from...

267

VISUAL MODELING AND SIMULATION OF MULTISCALE PHENOMENA Rahul Narain  

E-Print Network (OSTI)

as a dynamic texture over the fluid's surface, generated through optimization-based texture synthesis using-scale and fine-scale dynamics of a complex system. In fluid simulation, it remains a challenge to efficiently. . . . . . . . . . . . . . . . . . . . . . . 52 3.5 The energy spectrum of turbulent flow generated by 5 octaves of curl noise shows a power law

North Carolina at Chapel Hill, University of

268

Multi-scale Modeling and Experimental Validation of the Mechanical ...  

Science Conference Proceedings (OSTI)

Effects of Water Radiolysis on Stellite-6 Corrosion: Dependence on pH and Temperature · Environmentally Assisted Cracking Susceptibility Assessment of AP ...

269

Leveraging Data Science To Enable Multiscale Materials Modeling ...  

Science Conference Proceedings (OSTI)

Bayesian inference of grain boundary properties from heterogeneous data · Comparison of Novel Microstructure Quantification Frameworks for Visualization,  ...

270

Multiscale Modeling for Predicting Long-Term Behavior of Glass ...  

Science Conference Proceedings (OSTI)

Radioactive Demonstrations of Fluidized Bed Steam Reforming (FBSR) with Hanford Low Activity Wastes · Radionuclide Behavior and Geochemistry in Boom  ...

271

Final Report: Integrated Multiscale Modeling of Molecular Computing Devices  

Science Conference Proceedings (OSTI)

The general theme of this research has been to expand the capabilities of a simulation technique, Kinetic Monte Carlo (KMC) and apply it to study self-assembled nano-structures on epitaxial thin films. KMC simulates thin film growth and evolution by replacing the detailed dynamics of the systemâ??s evolution, which might otherwise be studied using molecular dynamics, with an appropriate stochastic process.

Tim Schulze, University of Tennessee, Knoxville

2012-11-01T23:59:59.000Z

272

Towards next generation ocean models : novel discontinuous Galerkin schemes for 2D unsteady biogeochemical models  

E-Print Network (OSTI)

A new generation of efficient parallel, multi-scale, and interdisciplinary ocean models is required for better understanding and accurate predictions. The purpose of this thesis is to quantitatively identify promising ...

Ueckermann, Mattheus P

2009-01-01T23:59:59.000Z

273

Parallel multiscale simulations of a brain aneurysm  

Science Conference Proceedings (OSTI)

Cardiovascular pathologies, such as a brain aneurysm, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales ... Keywords: Atomistic-continuum coupling, Blood microrheology, Dissipative particle dynamics, Domain decomposition, Parallel computing, Spectral elements, Thrombosis

Leopold Grinberg, Dmitry A. Fedosov, George Em Karniadakis

2013-07-01T23:59:59.000Z

274

Symmetry Methods for a Geophysical Mass Flow Model  

Science Conference Proceedings (OSTI)

In the framework of symmetry analysis, the class of 2 x 2 PDE systems to whom belong the Savage and Hutter model and the Iverson model is considered. New classes of exact solutions are found.

Torrisi, Mariano; Tracina, Rita [Dipartimento di Matematica e Informatica, Viale A. Doria 6, Catania (Italy)

2011-09-14T23:59:59.000Z

275

An Objective Method for Inferring Sources of Model Error  

Science Conference Proceedings (OSTI)

A restricted statistical correction (RSC) approach is introduced to assess the sources of error in general circulation models (GCMs). RSC models short-term forecast error by considering linear transformations of the GCM's forcing terms, which ...

Siegfried Schubert; Yehui Chang

1996-02-01T23:59:59.000Z

276

Search Method for Real-time Knowledge Discovery Modeled on ...  

nodes in a system of multiple computers according to rules for complex, hierarchical system modeled on the human brain.

277

A Bootstrap Method for Software Reliability Assessment Based on a Discretized NHPP Model  

Science Conference Proceedings (OSTI)

We discuss a bootstrap method for software reliability assessment based on a discretized no homogeneous Poisson process (NHPP) model. Ordinarily, model parameters of the discretized NHPP model are estimated by using the regression analysis based on the ... Keywords: Software reliability assessment, Discretized NHPP model, Regression analysis, Bootstrap method

Shinji Inoue; Shigeru Yamada

2012-11-01T23:59:59.000Z

278

An accelerating rendering method of hybrid point and polygon for complex three-dimensional models  

Science Conference Proceedings (OSTI)

This paper presents an accelerating hybrid rendering method for complex three-dimensional models using both points and polygons. In circumstance of current PC hardware, our rendering method that integrates advantages of both GBMR (Graphics -Based Modeling ... Keywords: continuous multi-resolution models, modeling and rendering, point clouds, real-time property, virtual reality

Aimin Hao; Guifen Tian; Qinping Zhao; Zhide Li

2006-11-01T23:59:59.000Z

279

Developing a time-domain finite-element method for modeling of electromagnetic cylindrical cloaks  

Science Conference Proceedings (OSTI)

In this paper we propose a time-domain finite element method for modeling of electromagnetic cloaks. The permittivity and permeability of the cloak model are described by the Drude dispersion model. The model to be solved is quite challenging in that ... Keywords: Finite element method, Invisibility cloak, Maxwell's equations

Jichun Li; Yunqing Huang; Wei Yang

2012-04-01T23:59:59.000Z

280

Automated geometric features evaluation method for normal foot skeleton model  

Science Conference Proceedings (OSTI)

"Normal foot model" is a geometric model of a healthy human foot. As the comparison of the processed feet requires a reference ideal healthy foot parameterization it was necessary to create such a model by defining skeleton geometric features and generating ...

Bartosz Borucki; Krzysztof Nowi?Ski; Micha? Chlebiej; Andrzej Rutkowski; Pawe? Adamczyk; Jacek Laskowski

2011-01-01T23:59:59.000Z

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


281

A Method of Evaluating Atmospheric Models Using Tracer Measurements  

Science Conference Proceedings (OSTI)

The authors have developed a method that uses tracer measurements as the basis for comparing and evaluating wind fields. An important advantage of the method is that the wind fields are evaluated from the tracer measurements without introducing ...

Darko Kora?in; James Frye; Vlad Isakov

2000-02-01T23:59:59.000Z

282

Multiscale Analysis of Pebble Bed Reactors  

SciTech Connect

– The PEBBED code was developed at the Idaho National Laboratory for design and analysis of pebble-bed high temperature reactors. The diffusion-depletion-pebble-mixing algorithm of the original PEBBED code was enhanced through coupling with the THERMIX-KONVEK code for thermal fluid analysis and by the COMBINE code for online cross section generation. The COMBINE code solves the B-1 or B-3 approximations to the transport equation for neutron slowing down and resonance interactions in a homogeneous medium with simple corrections for shadowing and thermal self-shielding. The number densities of materials within specified regions of the core are averaged and transferred to COMBINE from PEBBED for updating during the burnup iteration. The simple treatment of self-shielding in previous versions of COMBINE led to inaccurate results for cross sections and unsatisfactory core performance calculations. A new version of COMBINE has been developed that treats all levels of heterogeneity using the 1D transport code ANISN. In a 3-stage calculation, slowing down is performed in 167 groups for each homogeneous subregion (kernel, particle layers, graphite shell, control rod absorber annulus, etc.) Particles in a local average pebble are homogenized using ANISN then passed to the next (pebble) stage. A 1D transport solution is again performed over the pebble geometry and the homogenized pebble cross sections are passed to a 1-d radial model of a wedge of the pebble bed core. This wedge may also include homogeneous reflector regions and a control rod region composed of annuli of different absorbing regions. Radial leakage effects are therefore captured with discrete ordinates transport while axial and azimuthal effects are captured with a transverse buckling term. In this paper, results of various PBR models will be compared with comparable models from literature. Performance of the code will be assessed.

Hans Gougar; Woo Yoon; Abderrafi Ougouag

2010-10-01T23:59:59.000Z

283

Systems, Methods and Computer Readable Media for Modeling ...  

INL has developed a set of methods to define measure, evaluate, track and predict performance and aging trends for advanced chemistry batteries, ...

284

A computationally efficient method of identifying generic fuzzy models  

Science Conference Proceedings (OSTI)

There is on-going interest in the application of adaptive fuzzy model-based predictive control techniques which attempt to formulate and solve the control problem when the systems are uncertain and non-linear. This paper proposes a computational efficient ... Keywords: Adaptive control, Air-conditioning system, Fuzzy control, Fuzzy relations, Fuzzy system models

Yue Wu; Arthur Dexter

2009-09-01T23:59:59.000Z

285

Multiscale Evaluation of the Improvements in Surface Snow Simulation through Terrain Adjustments to Radiation  

Science Conference Proceedings (OSTI)

The downwelling shortwave radiation on the earth’s land surface is affected by the terrain characteristics of slope and aspect. These adjustments, in turn, impact the evolution of snow over such terrain. This article presents a multiscale ...

Sujay V. Kumar; Christa D. Peters-Lidard; David Mocko; Yudong Tian

2013-02-01T23:59:59.000Z

286

A Systemic Analysis of Multiscale Deep Convective Variability over the Tropical Pacific  

Science Conference Proceedings (OSTI)

The multiscale tropical deep convective variability over the Pacific Ocean is examined with the 4-month high-resolution deep convection index (ITBB) derived from satellite imagery. With a systemic view, the complex phenomenon is described with ...

Wen-wen Tung; Mitchell W. Moncrieff; Jian-Bo Gao

2004-07-01T23:59:59.000Z

287

Real-time network traffic prediction based on a multiscale decomposition  

Science Conference Proceedings (OSTI)

The presence of the complex scaling behavior in network traffic makes accurate forecasting of the traffic a challenging task. In this paper we propose a multiscale decomposition approach to real time traffic prediction. The raw traffic data is first ...

Guoqiang Mao

2005-04-01T23:59:59.000Z

288

Multiscale Variability of the Flow during the North American Monsoon Experiment  

Science Conference Proceedings (OSTI)

The 2004 North American Monsoon Experiment (NAME) provided an unprecedented observing network for studying the structure and evolution of the North American monsoon. This paper focuses on multiscale characteristics of the flow during NAME from ...

Richard H. Johnson; Paul E. Ciesielski; Brian D. McNoldy; Peter J. Rogers; Richard K. Taft

2007-05-01T23:59:59.000Z

289

Cost-Sensitive top-down/bottom-up inference for multiscale activity recognition  

Science Conference Proceedings (OSTI)

This paper addresses a new problem, that of multiscale activity recognition. Our goal is to detect and localize a wide range of activities, including individual actions and group activities, which may simultaneously co-occur in high-resolution video. ...

Mohamed R. Amer; Dan Xie; Mingtian Zhao; Sinisa Todorovic; Song-Chun Zhu

2012-10-01T23:59:59.000Z

290

Multiscale Processes and Nonlinear Dynamics of the Circulation and Upwelling Events off Monterey Bay  

Science Conference Proceedings (OSTI)

The nonlinear multiscale dynamics of the Monterey Bay circulation during the Second Autonomous Ocean Sampling Network (AOSN-II) Experiment (August 2003) is investigated in an attempt to understand the complex processes underlying the highly ...

X. San Liang; Allan R. Robinson

2009-02-01T23:59:59.000Z

291

Multiscale Convective Overturning in Mesoscale Convective Systems: Reconciling Observations, Simulations, and Theory  

Science Conference Proceedings (OSTI)

An analysis of how parameterized convection interacts with hydrostatic, explicitly resolved precipitation processes to represent multiscale convective overturning in a mesoscale-resolution numerical simulation is presented. Critically important ...

John S. Kain; J. Michael Fritsch

1998-08-01T23:59:59.000Z

292

A novel multi-scale intensity metric for evaluation of tropical cyclone intensity forecasts  

Science Conference Proceedings (OSTI)

In this study, a new Multi-Scale Intensity (MSI) metric for evaluating Tropical Cyclone (TC) intensity forecasts is presented. The metric consists of the resolvable and observable, low wavenumber intensity represented by the sum of amplitudes of ...

Tomislava Vukicevic; Eric Uhlhorn; Paul Reasor; Bradley Klotz

293

Application of an Inverse Method to Coastal Modeling  

Science Conference Proceedings (OSTI)

Free surface coastal models currently suffer from the difficulty of having to specify the global circulation during the initialization process and along the open boundaries. As an alternative to the long spinup periods, an original explicit ...

F. Auclair; S. Casitas; P. Marsaleix

2000-10-01T23:59:59.000Z

294

Evaluation of 10 Methods for Initializing a Land Surface Model  

Science Conference Proceedings (OSTI)

Improper initialization of numerical models can cause spurious trends in the output, inviting erroneous interpretations of the earth system processes that one wishes to study. In particular, soil moisture memory is considerable, so that accurate ...

M. Rodell; P. R. Houser; A. A. Berg; J. S. Famiglietti

2005-04-01T23:59:59.000Z

295

CBE EnergyPlus Modeling Methods for UFAD Systems  

E-Print Network (OSTI)

For these studies the fan design volume (and fan size) willall use the same AHU Fan design static pressure (FSP). ThisMethods for UFAD Systems Fan design efficiencies EnergyPlus

Webster, Tom; Bauman, Fred; Lee, Kwang Ho; Schiavon, Stefano; Daly, Alan; Hoyt, Tyler

2012-01-01T23:59:59.000Z

296

Finite volume methods for unidirectional dispersive wave models  

E-Print Network (OSTI)

We extend the framework of the finite volume method to dispersive unidirectional water wave propagation in one space dimension. In particular we consider a KdV-BBM type equation. Explicit and IMEX Runge-Kutta type methods are used for time discretizations. The fully discrete schemes are validated by direct comparisons to analytic solutions. Invariants conservation properties are also studied. Main applications include important nonlinear phenomena such as dispersive shock wave formation, solitary waves and their various interactions.

Dutykh, Denys; Mitsotakis, Dimitrios

2010-01-01T23:59:59.000Z

297

Modelling well leakage in multilayer aquifer systems using the extended finite element method  

Science Conference Proceedings (OSTI)

The extended finite element method (XFEM) is applied to the problem of predicting the steady-state leakage from layered sedimentary aquifer systems perforated by abandoned wells. Multi-aquifer systems are modelled using a quasi-three-dimensional model ... Keywords: Extended finite element method, GFEM, Generalised finite element method, Leakage, Multi-aquifer systems, XFEM

Robert Gracie; James R. Craig

2010-06-01T23:59:59.000Z

298

An Assessment of Radiation Damage Models and Methods  

SciTech Connect

The current state of development of the primary models used for investigating and simulating irradiation effects in structural alloys of interest to the U.S. DOE's Generation-IV reactor program are discussed. The underlying theory that supports model development is also described where appropriate. First, the key processes that underlie radiation-induced changes in material properties are summarized, and the types of radiation effects that subsequently arise are described. Future development work needed in order for theory, modeling, and computational materials science to support and add value to the Gen IV reactor materials program are then outlined. The expected specific outcomes and overall benefits of the required effort are: the knowledge to extrapolate material behavior to conditions for which there are no experimental data; systematic understanding of mechanisms and processes to enable confident interpolation between point-by-point experimental observations; acceleration of the development, selection, and qualification of materials for reactor service; and prediction of material response to real-world operating load histories which often involve a complicated superposition of time, temperature, radiation dose rate, and mechanical loading conditions. Opportunities for international collaboration to accelerate progress in all of the required research areas are briefly discussed, particularly in the context of two well coordinated, broad-based research projects on modeling and simulation of radiation effects on materials that are currently funded in Europe. In addition to providing the opportunity for substantial leveraging of the DOE-funded activities in this area, these projects may serve as models for future development within the Gen-IV program. The larger of these two projects, which involves 12 European research laboratories and 16 universities, is called PERFECT and is funded by the European Union. A smaller effort focusing on developing predictive models for fusion reactor materials is funded within the United Kingdom. Increased formal collaboration with these projects by DOE-funded materials scientists would be of substantial benefit to the Gen-IV program.

Stoller, Roger E [ORNL; Mansur, Louis K [ORNL

2005-05-01T23:59:59.000Z

299

Microsoft PowerPoint - Multi-Scale Computational_Perepezko  

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

Scale Computational Design Scale Computational Design and Synthesis of Protective Smart Coatings for Refractory Metal Alloys John H. Perepezko (PI), Otto J. Lu-Steffes Dept. Materials Science & Engineering, University of Wisconsin-Madison Grant Number: FE0007377 Performance Period: 5/31/12-6/11/13 OUTLINE: * Background on coating design and synthesis * Gaseous Computational Thermodynamic Designs for Coating Deposition Process * Phase Stability Analysis on the Coating Phase Constituents; emphasis on extended alloying capability * Microstructure-based FEA designs in Mo-RM-Si-B Coating Structures * Synthesis of Mo-Ti/Zr-Si-B Coatings * Oxidation tests at ultra-high temperatures Multi-scale Designs & Synthesis Approach for Mo-Si-B Based Smart Coatings

300

Computational Design of Novel Multiscale Concrete Rheometers | Argonne  

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

Suspended particles in a rheometer Suspended particles in a rheometer This simulation image shows suspended particles in a rheometer for NIST's proposed mortar SRM. The spheres, which are color coded by their starting location in the rheometer, are suspended in a cement paste with properties derived from NIST's cement paste SRM. Nicos Martys and Steven G. Satterfield, National Institute of Standards and Technology Computational Design of Novel Multiscale Concrete Rheometers PI Name: William George PI Email: wgeorge@nist.gov Institution: National Institute of Standards and Technology (NIST) Allocation Program: INCITE Allocation Hours at ALCF: 40 Million Year: 2014 Research Domain: Materials Science Understanding the mechanisms of dispersion or agglomeration of particulate matter in complex fluids, such as suspensions, is of technological

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


301

Propagation of radiation in fluctuating multiscale plasmas. I. Kinetic theory  

SciTech Connect

A theory for propagation of radiation in a large scale plasma with small scale fluctuations is developed using a kinetic description in terms of the probability distribution function of the radiation in space, time, and wavevector space. Large scale effects associated with spatial variations in the plasma density and refractive index of the plasma wave modes and small scale effects such as scattering of radiation by density clumps in fluctuating plasma, spontaneous emission, damping, and mode conversion are included in a multiscale kinetic description of the radiation. Expressions for the Stokes parameters in terms of the probability distribution function of the radiation are used to enable radiation properties such as intensity and polarization to be calculated.

Tyshetskiy, Yu.; Pal Singh, Kunwar; Thirunavukarasu, A.; Robinson, P. A.; Cairns, Iver H. [School of Physics, University of Sydney, NSW 2006 (Australia)

2012-11-15T23:59:59.000Z

302

Information fusion for wireless sensor networks: Methods, models, and classifications  

Science Conference Proceedings (OSTI)

Wireless sensor networks produce a large amount of data that needs to be processed, delivered, and assessed according to the application objectives. The way these data are manipulated by the sensor nodes is a fundamental issue. Information fusion arises ... Keywords: Information fusion, architectures and models, data aggregation, data fusion, wireless sensor networks

Eduardo F. Nakamura; Antonio A. F. Loureiro; Alejandro C. Frery

2007-09-01T23:59:59.000Z

303

An Immersed Boundary Method for the Weather Research and Forecasting Model  

Science Conference Proceedings (OSTI)

This paper describes an immersed boundary method that facilitates the explicit resolution of complex terrain within the Weather Research and Forecasting (WRF) model. Mesoscale models, such as WRF, are increasingly used for high-resolution ...

Katherine A. Lundquist; Fotini Katopodes Chow; Julie K. Lundquist

2010-03-01T23:59:59.000Z

304

Comparison between Wavenumber Truncation and Horizontal Diffusion Methods in Spectral Models  

Science Conference Proceedings (OSTI)

Commonly used horizontal diffusion and wavenumber truncation dealiasing methods in spectral models are verified using the National Center for Atmospheric Research Community Climate Model version 3. For the same horizontal grid resolution, time ...

Peter C. Chu; Xiong-Shan Chen; Chenwu Fan

2001-01-01T23:59:59.000Z

305

Application of a Multigrid Method to a Mass-Consistent Diagnostic Wind Model  

Science Conference Proceedings (OSTI)

A multigrid numerical method has been applied to a three-dimensional, high-resolution diagnostic model for flow over complex terrain using a mass-consistent approach. The theoretical background for the model is based on a variational analysis ...

Yansen Wang; Chatt Williamson; Dennis Garvey; Sam Chang; James Cogan

2005-07-01T23:59:59.000Z

306

Tracer Conservation with an Explicit Free Surface Method for z-Coordinate Ocean Models  

Science Conference Proceedings (OSTI)

This paper details a free surface method using an explicit time stepping scheme for use in z-coordinate ocean models. One key property that makes the method especially suitable for climate simulations is its very stable numerical time stepping ...

Stephen M. Griffies; Ronald C. Pacanowski; Martin Schmidt; V. Balaji

2001-05-01T23:59:59.000Z

307

An Objective Method for Determining the Generalized Transport Tensor for Two-Dimensional Eulerian Models  

Science Conference Proceedings (OSTI)

An objective method for deriving the components of a generalized transport tensor for a two-dimensional model is presented. The method uses representative meridional and vertical velocities and thermodynamic scalars at a uniform grid to reduce ...

Edwin F. Danielsen

1981-07-01T23:59:59.000Z

308

Towards Development of a Multiphase Simulation Model Using Lattice Boltzmann Method (LBM).  

E-Print Network (OSTI)

??Lattice Boltzmann Method is evolving as a substitute to the prevalent and predominant CFD modeling especially in cases such as multiphase flows, porous media flows… (more)

Koosukuntla, Narender Reddy

2011-01-01T23:59:59.000Z

309

Search Method for Real-time Knowledge Discovery Modeled on the ...  

Search Method for Real-time Knowledge Discovery Modeled on the Human Brain Oak Ridge National Laboratory. Contact ORNL About This Technology

310

System and method for modeling and analyzing complex scenarios  

SciTech Connect

An embodiment of the present invention includes a method for analyzing and solving possibility tree. A possibility tree having a plurality of programmable nodes is constructed and solved with a solver module executed by a processor element. The solver module executes the programming of said nodes, and tracks the state of at least a variable through a branch. When a variable of said branch is out of tolerance with a parameter, the solver disables remaining nodes of the branch and marks the branch as an invalid solution. The valid solutions are then aggregated and displayed as valid tree solutions.

Shevitz, Daniel Wolf

2013-04-09T23:59:59.000Z

311

Review of Wind Energy Forecasting Methods for Modeling Ramping Events  

DOE Green Energy (OSTI)

Tall onshore wind turbines, with hub heights between 80 m and 100 m, can extract large amounts of energy from the atmosphere since they generally encounter higher wind speeds, but they face challenges given the complexity of boundary layer flows. This complexity of the lowest layers of the atmosphere, where wind turbines reside, has made conventional modeling efforts less than ideal. To meet the nation's goal of increasing wind power into the U.S. electrical grid, the accuracy of wind power forecasts must be improved. In this report, the Lawrence Livermore National Laboratory, in collaboration with the University of Colorado at Boulder, University of California at Berkeley, and Colorado School of Mines, evaluates innovative approaches to forecasting sudden changes in wind speed or 'ramping events' at an onshore, multimegawatt wind farm. The forecast simulations are compared to observations of wind speed and direction from tall meteorological towers and a remote-sensing Sound Detection and Ranging (SODAR) instrument. Ramping events, i.e., sudden increases or decreases in wind speed and hence, power generated by a turbine, are especially problematic for wind farm operators. Sudden changes in wind speed or direction can lead to large power generation differences across a wind farm and are very difficult to predict with current forecasting tools. Here, we quantify the ability of three models, mesoscale WRF, WRF-LES, and PF.WRF, which vary in sophistication and required user expertise, to predict three ramping events at a North American wind farm.

Wharton, S; Lundquist, J K; Marjanovic, N; Williams, J L; Rhodes, M; Chow, T K; Maxwell, R

2011-03-28T23:59:59.000Z

312

A hybrid particle-continuum method for hydrodynamics of complex fluids  

E-Print Network (OSTI)

A previously-developed hybrid particle-continuum method [J. B. Bell, A. Garcia and S. A. Williams, SIAM Multiscale Modeling and Simulation, 6:1256-1280, 2008] is generalized to dense fluids and two and three dimensional flows. The scheme couples an explicit fluctuating compressible Navier-Stokes solver with the Isotropic Direct Simulation Monte Carlo (DSMC) particle method [A. Donev and A. L. Garcia and B. J. Alder, ArXiv preprint 0908.0510]. To achieve bidirectional dynamic coupling between the particle (microscale) and continuum (macroscale) regions, the continuum solver provides state-based boundary conditions to the particle subdomain, while the particle solver provides flux-based boundary conditions for the continuum subdomain. The equilibrium diffusive (Brownian) motion of a large spherical bead suspended in a particle fluid is examined, demonstrating that the hybrid method correctly reproduces the velocity autocorrelation function of the bead but only if thermal fluctuations are included in the continuum solver. Finally, the hybrid is applied to the well-known adiabatic piston problem and it is found that the hybrid correctly reproduces the slow non-equilibrium relaxation of the piston toward thermodynamic equilibrium but, again, only the continuum solver includes stochastic (white-noise) flux terms. These examples clearly demonstrate the need to include fluctuations in continuum solvers employed in hybrid multiscale methods.

A. Donev; J. B. Bell; A. L. Garcia; B. J. Alder

2009-10-20T23:59:59.000Z

313

Methods for measurement of a dimensional characteristic and methods of predictive modeling related thereto  

DOE Patents (OSTI)

A method of optically determining a change in magnitude of at least one dimensional characteristic of a sample in response to a selected chamber environment. A magnitude of at least one dimension of the at least one sample may be optically determined subsequent to altering the at least one environmental condition within the chamber. A maximum change in dimension of the at least one sample may be predicted. A dimensional measurement apparatus for indicating a change in at least one dimension of at least one sample. The dimensional measurement apparatus may include a housing with a chamber configured for accommodating pressure changes and an optical perception device for measuring a dimension of at least one sample disposed in the chamber. Methods of simulating injection of a gas into a subterranean formation, injecting gas into a subterranean formation, and producing methane from a coal bed are also disclosed.

Robertson, Eric P (Idaho Falls, ID); Christiansen, Richard L. (Littleton, CO)

2007-10-23T23:59:59.000Z

314

Methods and apparatus for measurement of a dimensional characteristic and methods of predictive modeling related thereto  

DOE Patents (OSTI)

A method of optically determining a change in magnitude of at least one dimensional characteristic of a sample in response to a selected chamber environment. A magnitude of at least one dimension of the at least one sample may be optically determined subsequent to altering the at least one environmental condition within the chamber. A maximum change in dimension of the at least one sample may be predicted. A dimensional measurement apparatus for indicating a change in at least one dimension of at least one sample. The dimensional measurement apparatus may include a housing with a chamber configured for accommodating pressure changes and an optical perception device for measuring a dimension of at least one sample disposed in the chamber. Methods of simulating injection of a gas into a subterranean formation, injecting gas into a subterranean formation, and producing methane from a coal bed are also disclosed.

Robertson, Eric P (Idaho Falls, ID); Christiansen, Richard L. (Littleton, CO)

2007-05-29T23:59:59.000Z

315

An iterative stochastic ensemble method for parameter estimation of subsurface flow models  

Science Conference Proceedings (OSTI)

Parameter estimation for subsurface flow models is an essential step for maximizing the value of numerical simulations for future prediction and the development of effective control strategies. We propose the iterative stochastic ensemble method (ISEM) ... Keywords: Iterative stochastic ensemble method, Parameter estimation, Regularization, Subsurface flow models

Ahmed H. Elsheikh, Mary F. Wheeler, Ibrahim Hoteit

2013-06-01T23:59:59.000Z

316

An extended multiscale principle of virtual velocities approach for evolving microstructure  

DOE Green Energy (OSTI)

A hierarchical multiscale approach is presented for modeling microstructure evolution in heterogeneous materials. Preservation of momentum across each scale transition is incorporated through the application of the principle of virtual velocities at the fine scale giving rise to the appropriate continuum momentum balance equations at the coarse scale. In addition to satisfying momentum balance and invariance of momentum among scales, invariance of elastic free energy, stored free energy, and dissipation between two scales of observation is regarded as crucial to the physics of each scale transition. The preservation of this energy partitioning scheme is obtained through construction of constitutive relations within the framework of internal state variable theory. Internal state variables that are directly computed from the fine scale response are introduced to augment the state equations and describe the inelastic energy storage and dissipation within the fine scale. Evolution equations for these internal state variables must be consistent with the observed dissipation at the fine scale. By virtue of a second gradient kinematic decomposition, the framework naturally gives rise to couple stresses.

Luscher, Darby J [Los Alamos National Laboratory; Mcdowell, David L [GEORGIA TECH

2009-01-01T23:59:59.000Z

317

Optimum Model-E-GAMS for Distributed Energy System by using GAMS Method  

E-Print Network (OSTI)

LBNL-57983 Optimum Model-E-GAMS for Distributed Energy System by using GAMS Method Yongwen Yang by the Office of Electricity Delivery and Energy Reliability, Distributed Energy Program of the U.S. Department Model DER-CAM GAMS 2GAMS GAMS 2 (general) (algebraic) (modeling system) FORTRAN DOfor for

318

Synthesis of Numerical Methods for Modeling Wave Energy Converter-Point Absorbers: Preprint  

DOE Green Energy (OSTI)

During the past few decades, wave energy has received significant attention among all ocean energy formats. Industry has proposed hundreds of prototypes such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber as the technology to extract wave energy. Several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. However, no standardized method has been decided. To assist the development of wave energy conversion technologies, this report reviews the methods for modeling the floating-point absorber.

Li, Y.; Yu, Y. H.

2012-05-01T23:59:59.000Z

319

"Relaxing" - A Symbolic Sparse Matrix Method Exploiting the Model Structure in Generating Efficient Simulation Code  

E-Print Network (OSTI)

This paper presents a new method for symbolically solving large sets of algebraically coupled equations as they are frequently encountered in the formulation of mathematical models of physical systems in object-- oriented modeling. The method, called "relaxing," enables the modeler to exploit the special matrix structure of the type of system under study by simply placing the keyword relax at appropriate places in the model class libraries. This procedure defines an evaluation sequence for a sparse matrix Gaussian elimination scheme. The method is demonstrated at hand of several broad classes of physical systems: drive trains, electrical circuits, and tree--structured multibody systems. In particular, relaxing allows a model compiler, such as Dymola, to start from a declarative, object-- oriented description of the model, and to automatically derive the recursive O(f) algorithm used in modern multibody programs. Keywords: Sparse matrices; symbolic formulae manipulation; object--orient...

Martin Otter; Hilding Elmqvist François E. Cellier; Hilding Elmqvist; Francois E. Cellier

1996-01-01T23:59:59.000Z

320

A Method for Constraining Cosmic Magnetic Field Models Using Ultra-High Energy Cosmic Rays: The Field Scan Method  

E-Print Network (OSTI)

The Galactic magnetic field, locally observed to be on the order of a few $\\mu$G, is sufficiently strong to induce deflections in the arrival directions of ultra-high energy cosmic rays. We present a method that establishes measures of self-consistency for hypothesis sets comprised of cosmic magnetic field models and ultra-high energy cosmic ray composition and source distributions. The method uses two independent procedures to compare the backtracked velocity vectors outside the magnetic field model to the distribution of backtracked velocity directions of many isotropic observations with the same primary energies. This allows for an estimate of the statistical consistency between the observed data and simulated isotropic observations. Inconsistency with the isotropic expectation of source correlation in both procedures is interpreted as the hypothesis set providing a self-consistent description of GMF and UHECR properties for the cosmic ray observations.

Michael S. Sutherland; Brian M. Baughman; James J. Beatty

2012-07-06T23:59:59.000Z

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


321

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie  

Open Energy Info (EERE)

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie Valley-Central Nevada Seismic Belt Area- Implications from Mt Resistivity Surveying Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie Valley-Central Nevada Seismic Belt Area- Implications from Mt Resistivity Surveying Abstract Extended magnetotelluric (MT) profiling results over the Dixie Valley-Central Nevada Seismic Belt area were recently completed to explore the hypothesis that fluid circulation to depths of 10 km or more is generating well temperatures in the field >280 C.This transect has revealed families of resistivity structures commonly dominated by high-angle

322

Multiscale Curvature-Based Shape Representation Using B-spline Wavelets  

E-Print Network (OSTI)

This paper presents a new multiscale curvature-based shape representation technique with application to curve data compression using B-spline wavelets. The properties and behavior of evolving curves in B-spline scale-space are investigated. They are shown to be similar to that in Gaussian scale-space, but B-spline representation enjoys a number of advantages over Gaussian kernels, for instance, the availability of fast algorithms. As an application of the multiscale shape representation, we introduce an algorithm and present some illustrative examples on curve data compression. The B-spline wavelet transforms are used to estimate efficiently the multiscale curvature functions. Based on the curvature scale-space image, we introduce a coarse-to-fine matching algorithm to automatically detect the dominant points and use them as control knots for curve interpolation. Keywords: B-spline, diffusion equation, curve evolution, curvature function, curve fitting. EDICS category: 1.6, 1.8, 3.4 ...

Yu-Ping Wang; S.L. Lee; K. Torachi

1999-01-01T23:59:59.000Z

323

Impact of an Updated Carbon Bond Mechanism on Predictions from the CMAQ Modeling System: Preliminary Assessment  

Science Conference Proceedings (OSTI)

An updated and expanded version of the Carbon Bond mechanism (CB05) has been incorporated into the Community Multiscale Air Quality (CMAQ) modeling system to more accurately simulate wintertime, pristine, and high-altitude situations. The CB05 ...

Golam Sarwar; Deborah Luecken; Greg Yarwood; Gary Z. Whitten; William P. L. Carter

2008-01-01T23:59:59.000Z

324

Characteristics of the RAW Filtered Leapfrog Time-stepping Scheme in the Ocean General Circulation Model  

Science Conference Proceedings (OSTI)

The Robert-Asselin-Williams (RAW) filtered leapfrog scheme is implemented and tested in the Taiwan multi-scale community ocean model (TIMCOM). The characteristics of the RAW filter are carefully examined through two benchmark tests (the classical ...

Chih-Chieh Young; Yu-Chiao Liang; Yu-Heng Tseng; Chun-Hoe Chow

325

Mesoscale Modeling and Four-Dimensional Data Assimilation in Areas of Highly Complex Terrain  

Science Conference Proceedings (OSTI)

A multiscale four-dimensional data assimilation (FDDA) technique, based on Newtonian relaxation, is incorporated into a mesoscale model and evaluated using meteorological and tracer data collected during the Atmospheric Studies in Complex Terrain ...

J. D. Fast

1995-12-01T23:59:59.000Z

326

Some conservation issues for the dynamical cores of NWP and climate models  

Science Conference Proceedings (OSTI)

The rationale for designing atmospheric numerical model dynamical cores with certain conservation properties is reviewed. The conceptual difficulties associated with the multiscale nature of realistic atmospheric flow, and its lack of time-reversibility, ... Keywords: Climate simulation, Conservation, Weather prediction

J. Thuburn

2008-03-01T23:59:59.000Z

327

Linearization of a Simple Moist Convection Scheme for Large-Scale NWP Models  

Science Conference Proceedings (OSTI)

A simple Kuo-type convection scheme with an improved closure based on moist enthalpy accession (Kuo symmetric) has been linearized for the tangent-linear (TL) and adjoint (AD) versions of the Global Environmental Multiscale (GEM) model. The ...

Jean-François Mahfouf

2005-06-01T23:59:59.000Z

328

An Iterative Method for Constructing Equilibrium Phase Models of Stellar Systems  

E-Print Network (OSTI)

We present a new method for constructing equilibrium phase models for stellar systems, which we call the iterative method. It relies on constrained, or guided evolution, so that the equilibrium solution has a number of desired parameters and/or constraints. This method is very powerful, to a large extent due to its simplicity. It can be used for mass distributions with an arbitrary geometry and a large variety of kinematical constraints. We present several examples illustrating it. Applications of this method include the creation of initial conditions for N-body simulations and the modelling of galaxies from their photometric and kinematic observations.

S. A. Rodionov; E. Athanassoula; N. Ya Sotnikova

2008-08-14T23:59:59.000Z

329

A multigrid method for a model of the implicit immersed boundary equations  

SciTech Connect

Explicit time stepping schemes for the immersed boundary method require very small time steps in order to maintain stability. Solving the equations that arise from an implicit discretization is difficult. Recently, several different approaches have been proposed, but a complete understanding of this problem is still emerging. A multigrid method is developed and explored for solving the equations in an implicit time discretization of a model of the immersed boundary equations. The model problem consists of a scalar Poisson equation with conformation-dependent singular forces on an immersed boundary. This model does not include the inertial terms or the incompressibility constraint. The method is more efficient than an explicit method, but the efficiency gain is limited. The multigrid method alone may not be an effective solver, but when used as a preconditioner for Krylov methods, the speed-up over the explicit time method is substantial. For example, depending on the constitutive law for the boundary force, with a time step 100 times larger than the explicit method, the implicit method is about 15-100 times more efficient than the explicit method. A very attractive feature of this method is that the efficiency of the multigrid preconditioned Krylov solver is shown to be independent of the number of immersed boundary points.

Guy, Robert [University of California, Davis; Philip, Bobby [ORNL

2012-01-01T23:59:59.000Z

330

Solution of Nonlinear Finite Difference Ocean Models by Optimization Methods with Sensitivity and Observational Strategy Analysis  

Science Conference Proceedings (OSTI)

Dynamical models driven by “observed” forcing fields (e.g., the wind) have a true solution uncertainty owing to observational errors in the driving. This uncertainty is usually hidden from view because conventional numerical methods do not easily ...

Jens Schröter; Carl Wunsch

1986-11-01T23:59:59.000Z

331

The Pugh Controlled Convergence Method: Model-Based Evaluation and Implications for Design Theory  

E-Print Network (OSTI)

This paper evaluates the Pugh Controlled Convergence method and its relationship to recent developments in design theory. Computer executable models are proposed simulating a team of people involved in iterated cycles of ...

Wijnia, Ype

332

The Study of Compost Quality Evaluation Modeling Method Based on Fuzzy Neural Network for Sewage Treatment  

Science Conference Proceedings (OSTI)

Because of the complicated interaction of the sludge compost components, it makes the quality evaluation system of sludge compost appear the fuzziness. According to the physical circumstances of sludge compost, a compost quality evaluation modeling method ...

Jingwen Tian; Meijuan Gao; Yujuan Xiang

2007-07-01T23:59:59.000Z

333

Evolving Multisensor Precipitation Estimation Methods: Their Impacts on Flow Prediction Using a Distributed Hydrologic Model  

Science Conference Proceedings (OSTI)

This study investigates evolving methodologies for radar and merged gauge–radar quantitative precipitation estimation (QPE) to determine their influence on the flow predictions of a distributed hydrologic model. These methods include the National ...

David Kitzmiller; Suzanne Van Cooten; Feng Ding; Kenneth Howard; Carrie Langston; Jian Zhang; Heather Moser; Yu Zhang; Jonathan J. Gourley; Dongsoo Kim; David Riley

2011-12-01T23:59:59.000Z

334

Computational intelligence methods: joint use in discrete event simulation model of logistics processes  

Science Conference Proceedings (OSTI)

The objective of the paper is to present the concept of using selected computational intelligence methods in conjunction with discrete event simulation (DES) models of chosen logistics processes. A review of the recent literature in the scope of applications ...

Marek Karkula; Lech Bukowski

2012-12-01T23:59:59.000Z

335

Data Assimilation in a Baroclinic Coastal Ocean Model: Ensemble Statistics and Comparison of Methods  

Science Conference Proceedings (OSTI)

The performance of data assimilation methods in an idealized three-dimensional time-dependent coastal baroclinic model is assessed by computing ensemble error statistics. The analytical representer solution allows for computation of posterior ...

A. L. Kurapov; G. D. Egbert; R. N. Miller; J. S. Allen

2002-04-01T23:59:59.000Z

336

Sparse Models and Methods for Optimal Instruments with an Application to Eminent Domain  

E-Print Network (OSTI)

We develop results for the use of LASSO and Post-LASSO methods to form first-stage predictions and estimate optimal instruments in linear instrumental variables (IV) models with many instruments, p, that apply even when p ...

Belloni, Alexandre

2011-07-12T23:59:59.000Z

337

A Method for Coupling a Parameterization of the Planetary Boundary Layer with a Hydrologic Model  

Science Conference Proceedings (OSTI)

Deardorff's parameterization of the planetary boundary layer is adapted to drive a hydrologic model. The method converts the atmospheric conditions measured at the anemometer height at one site to the mean values in the planetary boundary layer ...

J. D. Lin; Shu Fen Sun

1986-12-01T23:59:59.000Z

338

Search Method for Real-time Knowledge Discovery Modeled on the ...  

ORNL 2011-G00262/jcn UT-B ID 200601732 08.2011 Search Method for Real-time Knowledge Discovery Modeled on the Human Brain Technology Summary A new ...

339

Development of models and methods for the molecular simulation of large systems and molecules  

E-Print Network (OSTI)

The most important factor for quantitative results in molecular dynamics simulation are well developed force fields and models. In the present work, the development of new models and the usage of force fields from the literature in large systems are presented. Both tasks lead to time consuming simulations that require massively parallel high performance computing. In the present work, new models for carbon dioxide and cyclohexanolare discussed and a new method for the model development is introduced. Force fields and models for the simulation of PNIPAAm hydrogel in pure water and sodium chloride solution are tested and verified and applied to the simulation of nucleation processes.

Walter, Jonathan; Horsch, Martin; Vrabec, Jadran; Hasse, Hans

2010-01-01T23:59:59.000Z

340

Supersonic combustion studies using a multivariate quadrature based method for combustion modeling  

E-Print Network (OSTI)

Supersonic combustion studies using a multivariate quadrature based method for combustion modeling function (PDF) of thermochemical variables can be used for accurately computing the combustion source term of predictive models for supersonic combustion is a critical step in design and development of scramjet engines

Raman, Venkat

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


341

A numerical method for solving convection-reaction-diffusion multivalued equations in fire spread modelling  

Science Conference Proceedings (OSTI)

A numerical method is developed for fire spread simulation modelling. The two-dimensional surface model presented takes into account moisture content, radiation, wind and slope effects, which are by far the most important mechanisms in fire spread. We ... Keywords: 02.60.Cb, 02.60.Lj, 02.70.Dh, Fire, Moisture, Pyrolysis, Radiation, Slope, Wind

L. Ferragut; M. I. Asensio; S. Monedero

2007-06-01T23:59:59.000Z

342

A hybrid analytical-heuristic method for calibrating land-use change models  

Science Conference Proceedings (OSTI)

Spatially explicit land-use models simulate the patterns of change on the landscape in response to coupled human-ecological dynamics. As these models become more complex involving larger than ever data sets, the need to improve calibration techniques ... Keywords: Amazon deforestation, Dinamica EGO, Genetic algorithm, Map comparison method, Spatial transition probability

Britaldo Soares-Filho; Hermann Rodrigues; Marco Follador

2013-05-01T23:59:59.000Z

343

A heuristic method to minimise the chattering problem in dynamic mathematical two-phase flow models  

Science Conference Proceedings (OSTI)

This paper introduces the chattering problem in dynamic mathematical two-phase flow models. The real system object of study is also introduced, the DISS test facility, a parabolic-trough solar power plant using as heat transfer fluid the steam-water ... Keywords: Chattering, Heuristic methods, Modelling and simulation, Parabolic-trough solar power plant, Two-phase flow, Zeno phenomenon

J. Bonilla; L. J. Yebra; S. Dormido

2011-09-01T23:59:59.000Z

344

Model order reduction methods for coupled systems in the time domain using Laguerre polynomials  

Science Conference Proceedings (OSTI)

In this paper, based on Laguerre polynomials, we present new methods for model reduction of coupled systems in the time domain. By appropriately selected projection matrices, a reduced order system is produced to retain the topology structure of the ... Keywords: Coupled systems, Function approximation, Laguerre polynomials, Model reduction, Structure preservation

Xiao-Long Wang; Yao-Lin Jiang

2011-10-01T23:59:59.000Z

345

Bayesian methods for the quantification of uncertainties in syngas chemistry models  

E-Print Network (OSTI)

Bayesian methods for the quantification of uncertainties in syngas chemistry models Kalen Braman, Todd Oliver and Venkat Raman, The University of Texas, Austin, Texas, 78712 Syngas chemistry modeling is an integral step toward the development of safe and ef- ficient syngas combustors. Although substantial effort

Raman, Venkat

346

Partial delamination modeling in composite beams using a finite element method  

Science Conference Proceedings (OSTI)

A new method of modeling partial delamination in composite beams is proposed and implemented using the finite element method. Homogenized cross-sectional stiffness of the delaminated beam is obtained by the proposed analytical technique, including extension-bending, ... Keywords: Beam element, Composites, Delamination, Timoshenko beam, Vibration

S. Keshava Kumar, Ranjan Ganguli, Dineshkumar Harursampath

2013-11-01T23:59:59.000Z

347

A Method for Direct Solution of a Steady Linearized Spectral General Circulation Model  

Science Conference Proceedings (OSTI)

A steady linearized version of a general circulation model (GCM) is a potentially useful tool for diagnosis and understanding of the time-mean solutions of the GCM. A method is developed for direct solution of the linearized equations. The method ...

Edwin K. Schneider

1989-10-01T23:59:59.000Z

348

A PDF-Based Model for Boundary Layer Clouds. Part I: Method and Model Description  

Science Conference Proceedings (OSTI)

A new cloudy boundary layer single-column model is presented. It is designed to be flexible enough to represent a variety of cloudiness regimes—such as cumulus, stratocumulus, and clear regimes—without the need for case-specific adjustments. The ...

Jean-Christophe Golaz; Vincent E. Larson; William R. Cotton

2002-12-01T23:59:59.000Z

349

Reaction-diffusion network for geometric multiscale high speed image processing  

Science Conference Proceedings (OSTI)

In the framework of heavy mid-level processing for high speed imaging, a nonlinear bi-dimensional network is proposed, allowing the implementation of active curve algorithms. Usually this efficient type of algorithm is prohibitive for real-time image ... Keywords: Image analysis, Multiscale geometry, Nonlinear signal processing

S. Binczak; T. Sliwa; S. Jacquir; J. M. Bilbault

2010-06-01T23:59:59.000Z

350

Sustainable adaptive grid supercomputing: multiscale simulation of semiconductor processing across the pacific  

Science Conference Proceedings (OSTI)

We propose a reservation-based sustainable adaptive Grid supercomputing paradigm to enable tightly coupled computations of considerable scale (involving over 1,000 processors) and duration (over tens of continuous days) on a Grid of geographically distributed ... Keywords: density functional theory, grid application, grid remote procedure call, message passing interface, molecular dynamics, multiscale simulation, quantum mechanics

Hiroshi Takemiya; Yoshio Tanaka; Satoshi Sekiguchi; Shuji Ogata; Rajiv K. Kalia; Aiichiro Nakano; Priya Vashishta

2006-11-01T23:59:59.000Z

351

Asymptotic expansion for pricing options for a mean-reverting asset with multiscale stochastic volatility  

Science Conference Proceedings (OSTI)

This work investigates the valuation of options when the underlying asset follows a mean-reverting log-normal process with a stochastic volatility that is driven by two stochastic processes with one persistent factor and one fast mean-reverting factor. ... Keywords: Mean reversion, Multiscale asymptotic, Option pricing, Stochastic volatility

Mei Choi Chiu; Yu Wai Lo; Hoi Ying Wong

2011-07-01T23:59:59.000Z

352

Resolving Oceanic Shear and Velocity with the Multi-Scale Profiler  

Science Conference Proceedings (OSTI)

The Multi-Scale Profiler (MSP), a freely falling dropsonde, has been used over the past 12 years to measure oceanic shear variance. Complete resolution of oceanic shear spectra is achieved by combining the measurements of MSP’s acoustic current ...

D. P. Winkel; M. C. Gregg; T. B. Sanford

1996-10-01T23:59:59.000Z

353

Formation of Nuclear Disks and Supermassive Black Hole Binaries in Multi-Scale Hydrodynamical Galaxy Mergers  

E-Print Network (OSTI)

(Abridged) We review the results of the first multi-scale, hydrodynamical simulations of mergers between galaxies with central supermassive black holes (SMBHs) to investigate the formation of SMBH binaries in galactic nuclei. We demonstrate that strong gas inflows produce nuclear disks at the centers of merger remnants whose properties depend sensitively on the details of gas thermodynamics. In numerical simulations with parsec-scale spatial resolution in the gas component and an effective equation of state appropriate for a starburst galaxy, we show that a SMBH binary forms very rapidly, less than a million years after the merger of the two galaxies. Binary formation is significantly suppressed in the presence of a strong heating source such as radiative feedback by the accreting SMBHs. We also present preliminary results of numerical simulations with ultra-high spatial resolution of 0.1 pc in the gas component. These simulations resolve the internal structure of the resulting nuclear disk down to parsec scales and demonstrate the formation of a central massive object (~ 10^8 Mo) by efficient angular momentum transport. This is the first time that a radial gas inflow is shown to extend to parsec scales as a result of the dynamics and hydrodynamics involved in a galaxy merger, and has important implications for the fueling of SMBHs. Due to the rapid formation of the central clump, the density of the nuclear disk decreases significantly in its outer region, reducing dramatically the effect of dynamical friction and leading to the stalling of the two SMBHs at a separation of ~1 pc. We discuss how the orbital decay of the black holes might continue in a more realistic model which incorporates star formation and the multi-phase nature of the ISM.

Lucio Mayer; Stelios Kazantzidis; Andres Escala

2008-07-22T23:59:59.000Z

354

Computational model, method, and system for kinetically-tailoring multi-drug chemotherapy for individuals  

DOE Patents (OSTI)

A method and system for tailoring treatment regimens to individual patients with diseased cells exhibiting evolution of resistance to such treatments. A mathematical model is provided which models rates of population change of proliferating and quiescent diseased cells using cell kinetics and evolution of resistance of the diseased cells, and pharmacokinetic and pharmacodynamic models. Cell kinetic parameters are obtained from an individual patient and applied to the mathematical model to solve for a plurality of treatment regimens, each having a quantitative efficacy value associated therewith. A treatment regimen may then be selected from the plurlaity of treatment options based on the efficacy value.

Gardner, Shea Nicole (San Leandro, CA)

2007-10-23T23:59:59.000Z

355

Modeling Plasma Flow in a Magnetic Nozzle with the Lattice-Boltzmann Method  

E-Print Network (OSTI)

Magnetic nozzles must convert thermal or gyro energy of the plasma to thrust while also inducing plasma detachment in order to be effective. Plasma detachment and methods to induce plasma detachment are examined. In particular, super Alfvenic detachment and resistive detachment are examined. A parametric study of the plasma flow is conducted. Plasma flow through a magnetic nozzle is simulated using a three-dimensional, timedependent magnetohydrodynamics (MHD) model. The MHD equations are modeled using the lattice-Boltzmann method and the linearized Boltzmann equation with the Bhatnagar-Gross-Krook operator for collisions. This thesis presents simulations of configurations and conditions related to the VASIMR propulsion scheme. This research demonstrates plasma detachment using resistive and super Alfvenic mechanisms by modeling plasma flow with the Lattice Boltzmann Method.

Ebersohn, Frans Hendrik

2010-05-01T23:59:59.000Z

356

The Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFC Focused on Hanford’s 300 Area Uranium Plume Quality Assurance Project Plan  

Science Conference Proceedings (OSTI)

The purpose of the project is to conduct research at an Integrated Field-Scale Research Challenge Site in the Hanford Site 300 Area, CERCLA OU 300-FF-5 (Figure 1), to investigate multi-scale mass transfer processes associated with a subsurface uranium plume impacting both the vadose zone and groundwater. The project will investigate a series of science questions posed for research related to the effect of spatial heterogeneities, the importance of scale, coupled interactions between biogeochemical, hydrologic, and mass transfer processes, and measurements/approaches needed to characterize a mass-transfer dominated system. The research will be conducted by evaluating three (3) different hypotheses focused on multi-scale mass transfer processes in the vadose zone and groundwater, their influence on field-scale U(VI) biogeochemistry and transport, and their implications to natural systems and remediation. The project also includes goals to 1) provide relevant materials and field experimental opportunities for other ERSD researchers and 2) generate a lasting, accessible, and high-quality field experimental database that can be used by the scientific community for testing and validation of new conceptual and numerical models of subsurface reactive transport.

Fix, N. J.

2008-01-31T23:59:59.000Z

357

Multiscale Studies of the Formation and Stability of Surface-based Nanostructures, DOE Computational Materials Science Network - Final Report  

SciTech Connect

Summary of work performed under DOE-CMSN/FG0205ER46227, Multiscale Studies of the Formation and Stability of Surface-based Nanostructures, listing publications, collaborations, and presentations.

Einstein, Theodore L.

2011-10-31T23:59:59.000Z

358

An application of probabilistic safety assessment methods to model aircraft systems and accidents  

DOE Green Energy (OSTI)

A case study modeling the thrust reverser system (TRS) in the context of the fatal accident of a Boeing 767 is presented to illustrate the application of Probabilistic Safety Assessment methods. A simplified risk model consisting of an event tree with supporting fault trees was developed to represent the progression of the accident, taking into account the interaction between the TRS and the operating crew during the accident, and the findings of the accident investigation. A feasible sequence of events leading to the fatal accident was identified. Several insights about the TRS and the accident were obtained by applying PSA methods. Changes proposed for the TRS also are discussed.

Martinez-Guridi, G.; Hall, R.E.; Fullwood, R.R.

1998-08-01T23:59:59.000Z

359

Modeling Wet Snow Accretion on Power Lines: Improvements to Previous Methods Using 50 Years of Observations  

Science Conference Proceedings (OSTI)

Methods to model wet snow accretion on structures are developed and improved, based on unique records of wet snow icing events as well as large datasets of observed and simulated weather. Hundreds of observed wet snow icing events are logged in ...

Bjørn Egil Kringlebotn Nygaard; Hálfdán Ágústsson; Katalin Somfalvi-Tóth

2013-10-01T23:59:59.000Z

360

Modeling Wet Snow Accretion on Power Lines: Improvements to Previous Methods Using 50 Years of Observations  

Science Conference Proceedings (OSTI)

Methods to model wet snow accretion on structures are developed and improved, based on unique records of wet snow icing events as well as large datasets of observed and simulated weather. Hundreds of observed wet snow icing events are logged in ...

Bjørn Egil Kringlebotn Nygaard; Hálfdán Ágústsson; Katalin Somfalvi-Tóth

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


361

Fire emergency evacuation simulation based on integrated fire-evacuation model with discrete design method  

Science Conference Proceedings (OSTI)

Emergency evacuation under fire condition in a mass transit station is a great concern especially in developing countries. The interaction between fire and human is very important in the analysis of emergency evacuation under fire condition. An integrated ... Keywords: Discrete design method, Emergency evacuation, FDS+Evac, Fire-evacuation model, Total evacuation time, Waiting time

Peizhong Yang, Chao Li, Dehu Chen

2013-11-01T23:59:59.000Z

362

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow computations  

Science Conference Proceedings (OSTI)

It is well known that for increasingly rarefied flowfields, the predictions from continuum formulation, such as the Navier-Stokes equations lose accuracy. For the high speed diatomic molecular flow in the transitional regime, the inaccuracies are partially ... Keywords: Gas-kinetic method, Hypersonic and rarefied flows, Multiple temperature kinetic model

Kun Xu; Xin He; Chunpei Cai

2008-07-01T23:59:59.000Z

363

Cylindrical model of transient heat conduction in automotive fuse using conservative averaging method  

Science Conference Proceedings (OSTI)

Cylindrical mathematical model of automotive fuse is considered in this paper. Initially, partial differential equations of the transient heat conduction are given to describe heat-up process in the fuse. Conservative averaging method is used to obtain ... Keywords: analytical approximation, automotive fuse, conservative averaging, heat transfer, quasi-linear, transient process

Raimonds Vilums; Hans-Dieter Liess; Andris Buikis; Andis Rudevics

2008-12-01T23:59:59.000Z

364

Robust model based control method for wind energy production A. Pintea 1  

E-Print Network (OSTI)

Robust model based control method for wind energy production A. Pintea 1 , D. Popescu 1 , Ioana change effects will come to dominate every part of the earth. Wind power energy represents an interesting alternative to traditional forms of obtaining energy. However, the efficiency of wind power strongly depends

Paris-Sud XI, Université de

365

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

DOE Patents (OSTI)

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

Danko, George (Reno, NV)

2011-11-22T23:59:59.000Z

366

Coupled-cluster method: A lattice-path-based subsystem approximation scheme for quantum lattice models  

Science Conference Proceedings (OSTI)

An approximation hierarchy, called the lattice-path-based subsystem (LPSUBm) approximation scheme, is described for the coupled-cluster method (CCM). It is applicable to systems defined on a regular spatial lattice. We then apply it to two well-studied prototypical (spin-(1/2) Heisenberg antiferromagnetic) spin-lattice models, namely, the XXZ and the XY models on the square lattice in two dimensions. Results are obtained in each case for the ground-state energy, the ground-state sublattice magnetization, and the quantum critical point. They are all in good agreement with those from such alternative methods as spin-wave theory, series expansions, quantum Monte Carlo methods, and the CCM using the alternative lattice-animal-based subsystem (LSUBm) and the distance-based subsystem (DSUBm) schemes. Each of the three CCM schemes (LSUBm, DSUBm, and LPSUBm) for use with systems defined on a regular spatial lattice is shown to have its own advantages in particular applications.

Bishop, R. F.; Li, P. H. Y. [School of Physics and Astronomy, Schuster Building, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-04-15T23:59:59.000Z

367

Method  

E-Print Network (OSTI)

Abstract: The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 °C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled “Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions—Method by analysis of evolved carbon dioxide—Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test”. The evolved CO2 was trapped by an additional aqueous Ba(OH)2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the 14 C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO2 (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30 % lower than those based on the ISO method. These differences between the

Masao Kunioka; Fumi Ninomiya; Masahiro Funabashi

2009-01-01T23:59:59.000Z

368

Model Representation of Local Air Quality Characteristics  

Science Conference Proceedings (OSTI)

Daily (24 h) and hourly air quality data at several sites are used to examine the performance of the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5)–Community Multiscale Air Quality Model (CMAQ) system over a 3-month ...

Stephen F. Mueller

2009-05-01T23:59:59.000Z

369

Commercial Implementation of Model-Based Manufacturing of Nanostructured Metals  

SciTech Connect

Computational modeling is an essential tool for commercial production of nanostructured metals. Strength is limited by imperfections at the high strength levels that are achievable in nanostructured metals. Processing to achieve homogeneity at the micro- and nano-scales is critical. Manufacturing of nanostructured metals is intrinsically a multi-scale problem. Manufacturing of nanostructured metal products requires computer control, monitoring and modeling. Large scale manufacturing of bulk nanostructured metals by Severe Plastic Deformation is a multi-scale problem. Computational modeling at all scales is essential. Multiple scales of modeling must be integrated to predict and control nanostructural, microstructural, macrostructural product characteristics and production processes.

Lowe, Terry C. [Los Alamos National Laboratory

2012-07-24T23:59:59.000Z

370

Methods  

E-Print Network (OSTI)

The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals.permissions@oxfordjournals.org

Dave Mcgeoghegan; Keith Binks; Michael Gillies; Steve Jones; Steve Whaley

2008-01-01T23:59:59.000Z

371

In silico method for modelling metabolism and gene product expression at genome scale  

Science Conference Proceedings (OSTI)

Transcription and translation use raw materials and energy generated metabolically to create the macromolecular machinery responsible for all cellular functions, including metabolism. A biochemically accurate model of molecular biology and metabolism will facilitate comprehensive and quantitative computations of an organism's molecular constitution as a function of genetic and environmental parameters. Here we formulate a model of metabolism and macromolecular expression. Prototyping it using the simple microorganism Thermotoga maritima, we show our model accurately simulates variations in cellular composition and gene expression. Moreover, through in silico comparative transcriptomics, the model allows the discovery of new regulons and improving the genome and transcription unit annotations. Our method presents a framework for investigating molecular biology and cellular physiology in silico and may allow quantitative interpretation of multi-omics data sets in the context of an integrated biochemical description of an organism.

Lerman, Joshua A.; Hyduke, Daniel R.; Latif, Haythem; Portnoy, Vasiliy A.; Lewis, Nathan E.; Orth, Jeffrey D.; Rutledge, Alexandra C.; Smith, Richard D.; Adkins, Joshua N.; Zengler, Karsten; Palsson, Bernard O.

2012-07-03T23:59:59.000Z

372

Numerical prediction of aerodynamic characteristics of prismatic cylinder by finite element method with Spalart-Allmaras turbulence model  

Science Conference Proceedings (OSTI)

Aerodynamic characteristic of prismatic cylinders is numerically investigated by using finite element method with Spalart-Allmaras turbulence model. The developed model is verified against the available experimental and numerical results for turbulent ... Keywords: Aerodynamic characteristic, Afterbody shape, Finite element method, Prismatic cylinder, Turbulent flow, Unsteady S-A model

Yan Bao; Dai Zhou; Cheng Huang; Qier Wu; Xiang-qiao Chen

2011-02-01T23:59:59.000Z

373

Performance of Long-Term Integrations of the Japan Meteorological Agency Nonhydrostatic Model Using the Spectral Boundary Coupling Method  

Science Conference Proceedings (OSTI)

The spectral boundary coupling (SBC) method, which is an approach used to couple a limited-area model with a large-scale model, was introduced into a nonhydrostatic model. To investigate whether the SBC method works well in a long-term ...

Kazuaki Yasunaga; Hidetaka Sasaki; Yasutaka Wakazuki; Teruyuki Kato; Chiashi Muroi; Akihiro Hashimoto; Sachie Kanada; Kazuo Kurihara; Masanori Yoshizaki; Yasuo Sato

2005-12-01T23:59:59.000Z

374

Continuous reservoir simulation model updating and forecasting using a markov chain monte carlo method  

E-Print Network (OSTI)

Currently, effective reservoir management systems play a very important part in exploiting reservoirs. Fully exploiting all the possible events for a petroleum reservoir is a challenge because of the infinite combinations of reservoir parameters. There is much unknown about the underlying reservoir model, which has many uncertain parameters. MCMC (Markov Chain Monte Carlo) is a more statistically rigorous sampling method, with a stronger theoretical base than other methods. The performance of the MCMC method on a high dimensional problem is a timely topic in the statistics field. This thesis suggests a way to quantify uncertainty for high dimensional problems by using the MCMC sampling process under the Bayesian frame. Based on the improved method, this thesis reports a new approach in the use of the continuous MCMC method for automatic history matching. The assimilation of the data in a continuous process is done sequentially rather than simultaneously. In addition, by doing a continuous process, the MCMC method becomes more applicable for the industry. Long periods of time to run just one realization will no longer be a big problem during the sampling process. In addition, newly observed data will be considered once it is available, leading to a better estimate. The PUNQ-S3 reservoir model is used to test two methods in this thesis. The methods are: STATIC (traditional) SIMULATION PROCESS and CONTINUOUS SIMULATION PROCESS. The continuous process provides continuously updated probabilistic forecasts of well and reservoir performance, accessible at any time. It can be used to optimize long-term reservoir performance at field scale.

Liu, Chang

2008-12-01T23:59:59.000Z

375

An Iterative Method for the Construction of Equilibrium N-Body Models for Stellar Disks  

E-Print Network (OSTI)

One widely used technique for the construction of equilibrium models of stellar disks is based on the Jeans equations and the moments of velocity distribution functions derived using these equations. Stellar disks constructed using this technique are shown to be "not entirely" in equilibrium. Our attempt to abandon the epicyclic approximation and the approximation of infinite isothermal layers, which are commonly adopted in this technique, failed to improve the situation substantially. We conclude that the main drawback of techniques based on the Jeans equations is that the system of equations employed is not closed, and therefore requires adopting an essentially ad hoc additional closure condition. A new iterative approach to constructing equilibrium N-body models with a given density distribution is proposed. The main idea behind this approach is that a model is first constructed using some approximation method, and is then allowed to adjust to an equilibrium state with the specified density and the required parameters of the velocity distribution remaining fixed in the process. This iterative approach was used to construct isotropic, spherically symmetric models and models of stellar disks embedded in an external potential. The numerical models constructed prove to be close to equilibrium. It is shown that the commonly adopted assumption that the profile of the radial velocity dispersion is exponential may be wrong. The technique proposed can be applied to a wide range of problems involving the construction of models of stellar systems with various geometries.

S. A. Rodionov; N. Ya. Sotnikova

2006-11-06T23:59:59.000Z

376

Modeling and Evaluation of Geophysical Methods for Monitoring and Tracking CO2 Migration  

Science Conference Proceedings (OSTI)

Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO{sub 2} being released into the atmosphere daily. Test sites for CO{sub 2} injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO{sub 2}. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO{sub 2} at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO{sub 2} injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data collection, and seismic interpretation. The data was input into GphyzCO2 to demonstrate a full implementation of the software capabilities. Part of the implementation investigated the limits of using geophysical methods to monitor CO{sub 2} injection sites. The results show that cross-hole EM numerical surveys are limited to under 100 meter borehole separation. Those results were utilized in executing numerical EM surveys that contain hypothetical CO{sub 2} injections. The outcome of the forward modeling shows that EM methods can detect the presence of CO{sub 2}.

Daniels, Jeff

2012-11-30T23:59:59.000Z

377

Long-time integration methods for mesoscopic models of pattern-forming systems  

Science Conference Proceedings (OSTI)

Spectral methods for simulation of a mesoscopic diffusion model of surface pattern formation are evaluated for long simulation times. Backwards-differencing time-integration, coupled with an underlying Newton-Krylov nonlinear solver (SUNDIALS-CVODE), is found to substantially accelerate simulations, without the typical requirement of preconditioning. Quasi-equilibrium simulations of patterned phases predicted by the model are shown to agree well with linear stability analysis. Simulation results of the effect of repulsive particle-particle interactions on pattern relaxation time and short/long-range order are discussed.

Abukhdeir, Nasser Mohieddin [Department of Chemical Engineering, University of Delaware, Newark, DE (United States); Vlachos, Dionisios G., E-mail: vlachos@udel.ed [Department of Chemical Engineering, University of Delaware, Newark, DE (United States); Katsoulakis, Markos [Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA (United States); Department of Applied Mathematics, University of Crete, Heraklion (Greece); Institute of Applied and Computational Mathematics, Foundation for Research and Technology Hellas, Heraklion (Greece); Plexousakis, Michael [Department of Applied Mathematics, University of Crete, Heraklion (Greece); Institute of Applied and Computational Mathematics, Foundation for Research and Technology Hellas, Heraklion (Greece)

2011-06-20T23:59:59.000Z

378

Extrapolation method in the Monte Carlo Shell Model and its applications  

SciTech Connect

We demonstrate how the energy-variance extrapolation method works using the sequence of the approximated wave functions obtained by the Monte Carlo Shell Model (MCSM), taking {sup 56}Ni with pf-shell as an example. The extrapolation method is shown to work well even in the case that the MCSM shows slow convergence, such as {sup 72}Ge with f5pg9-shell. The structure of {sup 72}Se is also studied including the discussion of the shape-coexistence phenomenon.

Shimizu, Noritaka; Abe, Takashi [Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); Utsuno, Yutaka [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Mizusaki, Takahiro [Institute of Natural Sciences, Senshu University, Tokyo, 101-8425 (Japan); Otsuka, Takaharu [Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); Center for Nuclear Study, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan (United States); Honma, Michio [Center for Mathematical Sciences, Aizu University, Aizu-Wakamatsu, Fukushima 965-8580 (Japan)

2011-05-06T23:59:59.000Z

379

Phase field and level set methods for modeling solute precipitation and/or dissolution  

Science Conference Proceedings (OSTI)

The dynamics of solid-liquid interfaces controlled by solute precipitation and/or dissolution due to the chemical reaction at the interface were computed in two dimensions using a phase field models. Sharp-interface asymptotic analysis demonstrated that the phase field solutions should converge to the proper sharp-interface precipitation/dissolution limit. For the purpose of comparison, the numerical solution of the sharp-interface model for solute precipitation/dissolution was directly solved using a level set method. In general, the phase field results are found in good agreement with the level set results for all reaction rates and geometry configurations. Present study supports the applications of both methods to more complicated and realistic reactive systems.

Xu, Zhijie; Huang, Hai; Li, Xiaoyi; Meakin, Paul

2012-01-02T23:59:59.000Z

380

Phase field and level set methods for modeling solute precipitation and/or dissolution  

Science Conference Proceedings (OSTI)

The dynamics of solid-liquid interfaces controlled by solute precipitation and/or dissolution due to the chemical reaction at the interface were computed in two dimensions using a phase field models. Sharp-interface asymptotic analysis demonstrated that the phase field solutions should converge to the proper sharp-interface precipitation/dissolution limit. For the purpose of comparison, the numerical solution of the sharp-interface model for solute precipitation/dissolution was directly solved using a level set method. In general, the phase field results are found in good agreement with the level set results for all reaction rates and geometry configurations investigated. Present study supports the applications of both methods to more complicated and realistic reactive systems, including the nuclear waste release and mineral precipitation and dissolution

Zhijie Xu; Hai Huang; Paul Meakin

2012-01-01T23:59:59.000Z

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381

Use of Multiple Verification Methods to Evaluate Forecasts of Convection from Hot- and Cold-Start Convection-Allowing Models  

Science Conference Proceedings (OSTI)

This study uses both traditional and newer verification methods to evaluate two 4-km grid-spacing Weather Research and Forecasting Model (WRF) forecasts: a “cold start” forecast that uses the 12-km North American Mesoscale Model (NAM) analysis and ...

Derek R. Stratman; Michael C. Coniglio; Steven E. Koch; Ming Xue

2013-02-01T23:59:59.000Z

382

METHOD  

E-Print Network (OSTI)

Environmental Management, Inc. It has been subject to the Agency’s peer and administrative review, and it has been approved for publication as an EPA document. The opinions, findings, and conclusions expressed herein are those of the contractor and not necessarily those of the EPA or other cooperating agencies. Mention of company or product names is not to be construed as an endorsement by the agency. Foreword The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation’s land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA’s research program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future. The National Risk Management Research Laboratory is the Agency’s center for investigation of technological and management approaches for reducing risks from threats to human health and the environment. The focus of the Laboratory’s research program is on methods for the prevention and control of pollution to air, land, water and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites and ground water; and prevention and control of indoor air pollution. The goal of this research effort is to catalyze development and implementation of innovative, cost-effective environmental technologies;

unknown authors

1995-01-01T23:59:59.000Z

383

An efficient modeling method for thermal stratification simulation in a BWR suppression pool  

SciTech Connect

The suppression pool in a BWR plant not only is the major heat sink within the containment system, but also provides major emergency cooling water for the reactor core. In several accident scenarios, such as LOCA and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; and the pool temperature distribution also affects the NPSHa (Available Net Positive Suction Head) and therefore the performance of the pump which draws cooling water back to the core. Current safety analysis codes use 0-D lumped parameter methods to calculate the energy and mass balance in the pool and therefore have large uncertainty in prediction of scenarios in which stratification and mixing are important. While 3-D CFD methods can be used to analyze realistic 3D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, therefore long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by 1-D transient partial differential equations and substructures such as free or wall jets are modeled with 1-D integral models. This allows very large reductions in computational effort compared to 3-D CFD modeling. The POOLEX experiments at Finland, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, are used for validation. GOTHIC lumped parameter models are used to obtain boundary conditions for BMIX++ code and CFD simulations. Comparison between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data is discussed in detail.

Haihua Zhao; Ling Zou; Hongbin Zhang; Hua Li; Walter Villanueva; Pavel Kudinov

2012-09-01T23:59:59.000Z

384

An extended finite element method for hydraulic fracture propagation in deformable porous media with the cohesive crack model  

Science Conference Proceedings (OSTI)

In this paper, a fully coupled numerical model is developed for the modeling of the hydraulic fracture propagation in porous media using the extended finite element method in conjunction with the cohesive crack model. The governing equations, which account ... Keywords: Cohesive crack propagation, Fluid flow, Fracturing porous media, Fully coupled model, Hydraulic fracturing, XFEM

T. Mohammadnejad, A. R. Khoei

2013-10-01T23:59:59.000Z

385

Initialization of a Limited Area Model: A Comparison between the Nonlinear Normal Mode and Bounded Derivative Methods  

Science Conference Proceedings (OSTI)

A nonlinear normal mode initialization method is applied to a baroclinic limited arm forecast model. This method is very effective in reducing the amplitude of the rapid oscillations during the first hours of the forecast. The results are ...

S. J. Bijlsma; L. M. Hafkenscheid

1986-08-01T23:59:59.000Z

386

A Direct Inverse Method for Inferring Open Boundary Conditions of a Finite-Element Linear Harmonic Ocean Circulation Model  

Science Conference Proceedings (OSTI)

A direct inverse method is presented for inferring numerical model open boundary conditions from interior observational data. The dynamical context of the method is the frequency-domain 3D linear shallow water equations. A set of weight matrices ...

Zhigang Xu

1998-12-01T23:59:59.000Z

387

An Immersed Boundary Method Enabling Large-Eddy Simulations of Flow over Complex Terrain in the WRF Model  

Science Conference Proceedings (OSTI)

This paper describes a three-dimensional immersed boundary method (IBM) that facilitates the explicit resolution of complex terrain within the Weather Research and Forecasting (WRF) model. Two interpolation methods—trilinear and inverse distance ...

Katherine A. Lundquist; Fotini Katopodes Chow; Julie K. Lundquist

2012-12-01T23:59:59.000Z

388

Method of computer generation and projection recording of microholograms for holographic memory systems: mathematical modelling and experimental implementation  

SciTech Connect

A method of computer generation and projection recording of microholograms for holographic memory systems is presented; the results of mathematical modelling and experimental implementation of the method are demonstrated. (holographic memory)

Betin, A Yu; Bobrinev, V I; Evtikhiev, N N; Zherdev, A Yu; Zlokazov, E Yu; Lushnikov, D S; Markin, V V; Odinokov, S B; Starikov, S N; Starikov, R S

2013-01-31T23:59:59.000Z

389

Statistical Properties of Nuclei by the Shell Model Monte Carlo Method  

E-Print Network (OSTI)

We use quantum Monte Carlo methods in the framework of the interacting nuclear shell model to calculate the statistical properties of nuclei at finite temperature and/or excitation energies. With this approach we can carry out realistic calculations in much larger configuration spaces than are possible by conventional methods. A major application of the methods has been the microscopic calculation of nuclear partition functions and level densities, taking into account both correlations and shell effects. Our results for nuclei in the mass region A ~ 50 - 70 are in remarkably good agreement with experimental level densities without any adjustable parameters and are an improvement over empirical formulas. We have recently extended the shell model theory of level statistics to higher temperatures, including continuum effects. We have also constructed simple statistical models to explain the dependence of the microscopically calculated level densities on good quantum numbers such as parity. Thermal signatures of pairing correlations are identified through odd-even effects in the heat capacity.

Y. Alhassid

2006-04-26T23:59:59.000Z

390

Aggregate Models based on Improved Group Methods for Simulation and Optimization of Distillation Systems  

E-Print Network (OSTI)

This note deals with aggregate models for complex distillation systems in largescale flowsheets. Group methods were originally devised for simple absorber and stripper calculations with no major extensions for handling distillation. In this work, group methods are systematically analyzed and further improved by modifying some of the previously proposed approximations. As a result, the improved group method exhibits accurate predictions and this is demonstrated using simulation and optimization case studies for a variety of chemical systems and operating conditions. It is observed that the prediction of output variables is in close agreement with that of the rigorous equilibrium stage model. In case of optimization problems, the optimal number of trays and feed locations differ by only one or two trays. The aggregate model can be applied in a sequence of steps in order to improve the reliability and robustness of the solution procedure. A rounding heuristic is also proposed which can provide near-optimal solutions with a significant reduction in computational time. ?To whom correspondence should be addressed.

Ravindra S. Kamath; Ignacio E. Grossmann; Lorenz T. Biegler

2009-01-01T23:59:59.000Z

391

Application of the Maximum Entropy Method to the (2 + 1)d Four-Fermion Model  

E-Print Network (OSTI)

We investigate spectral functions extracted using the Maximum Entropy Method from correlators measured in lattice simulations of the (2+1)-dimensional four-fermion model. This model is particularly interesting because it has both a chirally broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are only resonances. In the broken phase we study the elementary fermion, pion, sigma, and massive pseudoscalar meson; our results confirm the Goldstone nature of the ? and permit an estimate of the meson binding energy. We have, however, seen no signal of ? ? ?? decay as the chiral limit is approached. In the symmetric phase we observe a resonance of non-zero width in qualitative agreement with analytic expectations; in addition the ultra-violet behaviour of the spectral functions is consistent with the large non-perturbative anomalous dimension for fermion composite operators expected in this model. 1 1

C. R. Allton A; J. E. Clowser A; J. B. Kogut C; C. G. Strouthos A

2002-01-01T23:59:59.000Z

392

A novel method for modeling the recoil in W boson events at hadron collider  

E-Print Network (OSTI)

We present a new method for modeling the hadronic recoil in W->lnu events produced at hadron colliders. The recoil is chosen from a library of recoils in Z->ll data events and overlaid on a simulated W->lnu event. Implementation of this method requires that the data recoil library describe the properties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming 1 fb-1 of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the high precision measurements that will be possible with data from Run II of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.

V. M. Abazov

2009-07-21T23:59:59.000Z

393

Coupling pore-scale networks to continuum-scale models of porous media  

Science Conference Proceedings (OSTI)

Network modeling is a useful tool for investigating pore-scale behavior and in some cases for determining macroscopic information such as permeability, relative permeability, and capillary pressure. Physically representative network models are particularly ... Keywords: Coupling, Fractured porous media, Multiscale modeling, Network modeling, Pore-scale modeling

Matthew T. Balhoff; Karsten E. Thompson; Martin Hjortsø

2007-03-01T23:59:59.000Z

394

Simulation of Thermal Stratification in BWR Suppression Pools with One Dimensional Modeling Method  

Science Conference Proceedings (OSTI)

The suppression pool in a boiling water reactor (BWR) plant not only is the major heat sink within the containment system, but also provides the major emergency cooling water for the reactor core. In several accident scenarios, such as a loss-of-coolant accident and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; the pool temperature distribution also affects the NPSHa (available net positive suction head) and therefore the performance of the Emergency Core Cooling System and Reactor Core Isolation Cooling System pumps that draw cooling water back to the core. Current safety analysis codes use zero dimensional (0-D) lumped parameter models to calculate the energy and mass balance in the pool; therefore, they have large uncertainties in the prediction of scenarios in which stratification and mixing are important. While three-dimensional (3-D) computational fluid dynamics (CFD) methods can be used to analyze realistic 3-D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, resulting in a long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code (Berkeley mechanistic MIXing code in C++) has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by one-dimensional (1-D) transient partial differential equations and substructures (such as free or wall jets) are modeled with 1-D integral models. This allows very large reductions in computational effort compared to multi-dimensional CFD modeling. One heat-up experiment performed at the Finland POOLEX facility, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, is used for validation. Comparisons between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data are discussed in detail.

Haihua Zhao; Ling Zou; Hongbin Zhang

2014-01-01T23:59:59.000Z

395

A RECOMMENDED PASQUILL-GIFFORD STABILITY CLASSIFICATION METHOD FOR SAFETY BASIS ATMOSPHERIC DISPERSION MODELING AT SRS  

SciTech Connect

Several of the most common methods for estimating Pasquill-Gifford (PG) stability (turbulence) class were evaluated for use in modeling the radiological consequences of SRS accidental releases using the MELCOR Accident Consequence Code System, Ver. 2 (MACCS2). Evaluation criteria included: (1) the ability of the method to represent diffusion characteristics above a predominantly forested landscape at SRS, (2) suitability of the method to provide data consistent with the formulation of the MACCS2 model, and (3) the availability of onsite meteorological data to support implementation of the method The evaluation resulted in a recommendation that PG stability classification for regulatory applications at SRS should be based on measurements of the standard deviation of the vertical component of wind direction fluctuations, {sigma}{sub e}, collected from the 61-m level of the SRS meteorological towers, and processed in full accordance with EPA-454/R-99-005 (EPA, 2000). This approach provides a direct measurement that is fundamental to diffusion and captures explicitly the turbulence generated by both mechanical and buoyant forces over the characteristic surface (forested) of SRS. Furthermore, due to the potentially significant enhancement of horizontal fluctuations in wind direction from the occurrence of meander at night, the use of {sigma}{sub e} will ensure a reasonably conservative estimate of PG stability class for use in dispersion models that base diffusion calculations on a single value of PG stability class. Furthermore, meteorological data bases used as input for MACCS2 calculations should contain hourly data for five consecutive annual periods from the most recent 10 years.

Hunter, C.

2012-03-28T23:59:59.000Z

396

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

E-Print Network (OSTI)

the behavior of advanced batteries used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). # 2002 (hybrid electric vehicles, HEVs) by bat- teries has resulted in enhanced research into various aspects in the development of environmentally friendly vehicles powered either fully (electric vehicles, EVs) or partially

397

Combined seismic and hydraulic method of modeling flow in fractured low permeability rocks  

DOE Green Energy (OSTI)

Modeling flow of ground water in hard rocks where a network of fractures provides the dominant flow paths is a major problem. This paper summarizes a program of investigations currently underway in this laboratory to characterize the geometry of fractured rocks and develop methods of handling flow in such systems. Numerical models have been developed to investigate flow behavior in two- and three-dimensional fracture networks. The results demonstrate the insights that can be gained from modeling studies of fractured rocks. A key problem is gathering the necessary data on fracture geometry. Investigations have been started to determine how vertical seismic profiling (VSP) might be improved and applied to this problem. A VSP experiment in The Geysers geothermal field in northern California, where fracture orientation is known, produced shear wave splitting and velocity anisotropy in agreement with theory. The results suggest the potential application of 3-component, multi-source VSP data in determining fracture orientation and average spacing. We believe a combination of seismic and hydraulic methods can greatly enhance an understanding of fluid flow and transport in low permeability rock systems where fractures provide the dominant paths. 40 refs, 16 figs., 4 tabs.

Witherspoon, P.A.; Long, J.C.S.; Majer, E.L.; Myer, L.R.

1987-06-01T23:59:59.000Z

398

Spectral energy distribution modelling of Southern candidate massive protostars using the Bayesian inference method  

E-Print Network (OSTI)

Concatenating data from the millimetre regime to the infrared, we have performed spectral energy distribution modelling for 227 of the 405 millimetre continuum sources of Hill et al. (2005) which are thought to contain young massive stars in the earliest stages of their formation. Three main parameters are extracted from the fits: temperature, mass and luminosity. The method employed was Bayesian inference, which allows a statistically probable range of suitable values for each parameter to be drawn for each individual protostellar candidate. This is the first application of this method to massive star formation. The cumulative distribution plots of the SED modelled parameters in this work indicate that collectively, the sources without methanol maser and/or radio continuum associations (MM-only cores) display similar characteristics to those of high mass star formation regions. Attributing significance to the marginal distinctions between the MM-only cores and the high-mass star formation sample we draw hypotheses regarding the nature of the MM-only cores, including the possibility that the population itself is comprised of different types of source, and discuss their role in the formation scenarios of massive star formation. In addition, we discuss the usefulness and limitations of SED modelling and its application to the field. From this work, it is clear that within the valid parameter ranges, SEDs utilising current far-infrared data can not be used to determine the evolution of massive protostars or massive young stellar objects.

T. Hill; C. Pinte; V. Minier; M. G. Burton; M. R. Cunningham

2008-10-17T23:59:59.000Z

399

Can Drugs Enhance Hypofractionated Radiotherapy? A Novel Method of Modeling Radiosensitization Using In Vitro Data  

SciTech Connect

Purpose: Hypofractionated radiotherapy (hRT) is being explored for a number of malignancies. The potential benefit of giving concurrent chemotherapy with hRT is not known. We sought to predict the effects of combined modality treatments by using mathematical models derived from laboratory data. Methods and Materials: Data from 26 published clonogenic survival assays for cancer cell lines with and without the use of radiosensitizing chemotherapy were collected. The first three data points of the RT arm of each assay were used to derive parameters for the linear quadratic (LQ) model, the multitarget (MT) model, and the generalized linear quadratic (gLQ) model. For each assay and model, the difference between the predicted and observed surviving fractions at the highest tested RT dose was calculated. The gLQ model was fitted to all the data from each RT cell survival assay, and the biologically equivalent doses in 2-Gy fractions (EQD2s) of clinically relevant hRT regimens were calculated. The increase in cell kill conferred by the addition of chemotherapy was used to estimate the EQD2 of hRT along with a radiosensitizing agent. For comparison, this was repeated using conventionally fractionated RT regimens. Results: At a mean RT dose of 8.0 Gy, the average errors for the LQ, MT, and gLQ models were 1.63, 0.83, and 0.56 log units, respectively, favoring the gLQ model (p < 0.05). Radiosensitizing chemotherapy increased the EQD2 of hRT schedules by an average of 28% to 82%, depending on disease site. This increase was similar to the gains predicted for the addition of chemotherapy to conventionally fractionated RT. Conclusions: Based on published in vitro assays, the gLQ equation is superior to the LQ and MT models in predicting cell kill at high doses of RT. Modeling exercises demonstrate that significant increases in biologically equivalent dose may be achieved with the addition of radiosensitizing agents to hRT. Clinical study of this approach is warranted.

Ohri, Nitin; Dicker, Adam P. [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Lawrence, Yaacov Richard, E-mail: yaacovla@gmail.com [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Center for Translational Research in Radiation Oncology, Sheba Medical Center, Tel Hashomer (Israel)

2012-05-01T23:59:59.000Z

400

An adaptive projection method for the modeling of unsteady, low-Mach number combustion  

SciTech Connect

In this paper the authors present an adaptive projection method for modeling unsteady, low-Mach reacting flow in an unconfined region. The equations they solve are based on a model for low-Mach number combustion that consists of the evolution equations for density, species concentrations, enthalpy, and momentum coupled with a constraint on the divergence of the flow. The algorithm is based on a projection methodology in which they first advance the evolution equations and then solve an elliptic equation to enforce the divergence constraint. The adaptive mesh refinement (AMR) scheme uses a time-varying, hierarchical grid structure composed of uniform rectangular grids of varying resolution. The integration scheme on the grid hierarchy is a recursive procedure in which a coarse grid is advanced, fine grids are advanced multiple steps to reach the same time as the coarse grid, and the coarse and the fine grids are synchronized. The method is valid for multiple grids on each level and multiple levels of refinement. The method is currently implemented for laminar, axisymmetric flames with a reduced kinetics mechanism and a Lewis number of unity. Two methane-air flames, one steady and the other flickering, are presented as numerical examples.

Pember, R.B.; Howell, L.H.; Bell, J.B.; Colella, P.; Crutchfield, W.Y. [Lawrence Berkeley National Lab., CA (United States); Fiveland, W.A.; Jesse, J.P. [Babcock and Wilcox, Alliance, OH (United States)

1997-10-01T23:59:59.000Z

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


401

Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method  

E-Print Network (OSTI)

Better understanding and control of crack growth direction during hydraulic fracturing are essential for enhancing productivity of geothermal and petroleum reservoirs. Structural analysis of fracture propagation and impact on fluid flow is a challenging issue because of the complexity of rock properties and physical aspects of rock failure and fracture growth. Realistic interpretation of the complex interactions between rock deformation, fluid flow, heat transfer, and fracture propagation induced by fluid injection is important for fracture network design. In this work, numerical models are developed to simulate rock failure and hydraulic fracture propagation. The influences of rock deformation, fluid flow, and heat transfer on fracturing processes are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering a stochastic heterogeneity distribution. The constitutive modeling by the energy release rate-based damage evolution allows characterizing brittle rock failure and strength degradation. This approach is then used to simulate the sequential process of heterogeneous rock failures from the initiation of microcracks to the growth of macrocracks. The hydraulic fracturing path, especially for fractures emanating from inclined wellbores and closed natural fractures, often involves mixed mode fracture propagation. Especially, when the fracture is inclined in a 3D stress field, the propagation cannot be modeled using 2D fracture models. Hence, 2D/3D mixed-modes fracture growth from an initially embedded circular crack is studied using the damage mechanics approach implemented in a finite element method. As a practical problem, hydraulic fracturing stimulation often involves fluid pressure change caused by injected fracturing fluid, fluid leakoff, and fracture propagation with brittle rock behavior and stress heterogeneities. In this dissertation, hydraulic fracture propagation is simulated using a coupled fluid flow/diffusion and rock deformation analysis. Later THM analysis is also carried out. The hydraulic forces in extended fractures are solved using a lubrication equation. Using a new moving-boundary element partition methodology (EPM), fracture propagation through heterogeneous media is predicted simply and efficiently. The method allows coupling fluid flow and rock deformation, and fracture propagation using the lubrication equation to solve for the fluid pressure through newly propagating crack paths. Using the proposed model, the 2D/3D hydraulic fracturing simulations are performed to investigate the role of material and rock heterogeneity. Furthermore, in geothermal and petroleum reservoir design, engineers can take advantage of thermal fracturing that occurs when heat transfers between injected flow and the rock matrix to create reservoir permeability. These thermal stresses are calculated using coupled THM analysis and their influence on crack propagation during reservoir stimulation are investigated using damage mechanics and thermal loading algorithms for newly fractured surfaces.

Min, Kyoung

2013-08-01T23:59:59.000Z

402

Fast 2D non-LTE radiative modelling of prominences I. Numerical methods and benchmark results  

E-Print Network (OSTI)

New high-resolution spectropolarimetric observations of solar prominences require improved radiative modelling capabilities in order to take into account both multi-dimensional - at least 2D - geometry and complex atomic models. This makes necessary the use of very fast numerical schemes for the resolution of 2D non-LTE radiative transfer problems considering freestanding and illuminated slabs. The implementation of Gauss-Seidel and successive over-relaxation iterative schemes in 2D, together with a multi-grid algorithm, is thoroughly described in the frame of the short characteristics method for the computation of the formal solution of the radiative transfer equation in cartesian geometry. We propose a new test for multidimensional radiative transfer codes and we also provide original benchmark results for simple 2D multilevel atom cases which should be helpful for the further development of such radiative transfer codes, in general.

L. Leger; L. Chevallier; F. Paletou

2007-03-27T23:59:59.000Z

403

Multiscale analysis of nonlinear systems using computational homology  

DOE Green Energy (OSTI)

This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure Characterization - We extended our previous work on studying the time evolution of patterns associated with phase separation in conserved concentration fields. (6) Probabilistic Homology Validation - work on microstructure characterization is based on numerically studying the homology of certain sublevel sets of a function, whose evolution is described by deterministic or stochastic evolution equations. (7) Computational Homology and Dynamics - Topological methods can be used to rigorously describe the dynamics of nonlinear systems. We are approaching this problem from several perspectives and through a variety of systems. (8) Stress Networks in Polycrystals - we have characterized stress networks in polycrystals. This part of the project is aimed at developing homological metrics which can aid in distinguishing not only microstructures, but also derived mechanical response fields. (9) Microstructure-Controlled Drug Release - This part of the project is concerned with the development of topological metrics in the context of controlled drug delivery systems, such as drug-eluting stents. We are particularly interested in developing metrics which can be used to link the processing stage to the resulting microstructure, and ultimately to the achieved system response in terms of drug release profiles. (10) Microstructure of Fuel Cells - we have been using our computational homology software to analyze the topological structure of the void, metal and ceramic components of a Solid Oxide Fuel Cell.

Konstantin Mischaikow, Rutgers University /Georgia Institute of Technology, Michael Schatz, Georgia Institute of Technology, William Kalies, Florida Atlantic University, Thomas Wanner,George Mason University

2010-05-19T23:59:59.000Z

404

Multiscale analysis of nonlinear systems using computational homology  

DOE Green Energy (OSTI)

This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure Characterization - We extended our previous work on studying the time evolution of patterns associated with phase separation in conserved concentration fields. (6) Probabilistic Homology Validation - work on microstructure characterization is based on numerically studying the homology of certain sublevel sets of a function, whose evolution is described by deterministic or stochastic evolution equations. (7) Computational Homology and Dynamics - Topological methods can be used to rigorously describe the dynamics of nonlinear systems. We are approaching this problem from several perspectives and through a variety of systems. (8) Stress Networks in Polycrystals - we have characterized stress networks in polycrystals. This part of the project is aimed at developing homological metrics which can aid in distinguishing not only microstructures, but also derived mechanical response fields. (9) Microstructure-Controlled Drug Release - This part of the project is concerned with the development of topological metrics in the context of controlled drug delivery systems, such as drug-eluting stents. We are particularly interested in developing metrics which can be used to link the processing stage to the resulting microstructure, and ultimately to the achieved system response in terms of drug release profiles. (10) Microstructure of Fuel Cells - we have been using our computational homology software to analyze the topological structure of the void, metal and ceramic components of a Solid Oxide Fuel Cell.

Konstantin Mischaikow; Michael Schatz; William Kalies; Thomas Wanner

2010-05-24T23:59:59.000Z

405

Leaking method approach to surface transport in the Mediterranean Sea from a numerical ocean model  

E-Print Network (OSTI)

We use Lagrangian diagnostics (the leaking and the exchange methods) to characterize surface transport out of and between selected regions in the Western Mediterranean. Velocity fields are obtained from a numerical model. Residence times of water of Atlantic origin in the Algerian basin, with a strong seasonal dependence, are calculated. Exchange rates between these waters and the ones occupying the northern basin are also evaluated. At surface, northward transport is dominant, and involves filamental features and eddy structures that can be identified with the Algerian eddies. The impact on these results of the presence of small scale turbulent motions is evaluated by adding Lagrangian diffusion.

Judit Schneider; Vicente Fernandez; Emilio Hernandez-Garcia

2004-10-01T23:59:59.000Z

406

A stochastic variational multiscale method for diffusion in heterogeneous random media  

E-Print Network (OSTI)

are added to waterfloods to reduce interfacial tension or otherwise improve the mobility of the oil, can

Zabaras, Nicholas J.

407

Model updating of a dynamic system in a high-temperature environment based on a hierarchical method  

Science Conference Proceedings (OSTI)

In the past, structural model updating methods have been widely researched as a means to reconcile mathematical models because the key parameters in dynamic systems often change during their life cycle due to repair and replacement of parts or the environment. ... Keywords: Analysis variance, FE model updating, Genetic algorithm, Hierarchical, High temperature, RBF predictor

He Cheng, Chen Guoping, He Huan, Sun Rujie

2013-12-01T23:59:59.000Z

408

Modelling two-phase flow in porous media at the pore scale using the volume-of-fluid method  

Science Conference Proceedings (OSTI)

We present a stable numerical scheme for modelling multiphase flow in porous media, where the characteristic size of the flow domain is of the order of microns to millimetres. The numerical method is developed for efficient modelling of multiphase flow ... Keywords: Pore-scale modelling, Porous media, Two-phase flow, Volume of fluid

Ali Q. Raeini; Martin J. Blunt; Branko Bijeljic

2012-07-01T23:59:59.000Z

409

Review of hardware cost estimation methods, models and tools applied to early phases of space mission planning  

E-Print Network (OSTI)

Equipment; AHP, Analytic Hierarchy Process; AMCM, Advanced Missions Cost Model; ASPE, American SocietyReview of hardware cost estimation methods, models and tools applied to early phases of space Cost estimation Cost model Parametrics Space hardware Early mission phase a b s t r a c t The primary

Sekercioglu, Y. Ahmet

410

Convergence of methods for coupling of microscopic and mesoscopic reaction-diffusion simulations  

E-Print Network (OSTI)

In this paper, three multiscale methods for coupling of mesoscopic (compartment-based) and microscopic (molecular-based) stochastic reaction-diffusion simulations are investigated. Two of the three methods that will be discussed in detail have been previously reported in the literature; the two-regime method (TRM) and the compartment-placement method (CPM). The third method that is introduced and analysed in this paper is the ghost cell method (GCM). Presented is a comparison of sources of error. The convergent properties of this error are studied as the time step $\\Delta t$ (for updating the molecular-based part of the model) approaches zero. It is found that the error behaviour depends on another fundamental computational parameter $h$, the compartment size in the mesoscopic part of the model. Two important limiting cases, which appear in applications, are considered: (i) \\Delta t approaches 0 and h is fixed; and (ii) \\Delta t approaches 0 and h approaches 0 such that \\Delta t/h^2 is fixed. The error for previously developed approaches (the TRM and CPM) converges to zero only in the limiting case (ii), but not in case (i). It is shown that the error of the GCM converges in the limiting case (i). Thus the GCM is superior to previous coupling techniques if the mesoscopic description is much coarser than the microscopic part of the model.

Mark B Flegg; Stefan Hellander; Radek Erban

2013-04-27T23:59:59.000Z

411

Thermo-Poroelastic Modeling of Reservoir Stimulation and Microseismicity Using Finite Element Method with Damage Mechanics  

E-Print Network (OSTI)

Stress and permeability variations around a wellbore and in the reservoir are of much interest in petroleum and geothermal reservoir development. Water injection causes significant changes in pore pressure, temperature, and stress in hot reservoirs, changing rock permeability. In this work, two- and three-dimensional finite element methods were developed to simulate coupled reservoirs with damage mechanics and stress-dependent permeability. The model considers the influence of fluid flow, temperature, and solute transport in rock deformation and models nonlinear behavior with continuum damage mechanics and stress-dependent permeability. Numerical modeling was applied to analyze wellbore stability in swelling shale with two- and three-dimensional damage/fracture propagation around a wellbore and injection-induced microseismic events. The finite element method (FEM) was used to solve the displacement, pore pressure, temperature, and solute concentration problems. Solute mass transport between drilling fluid and shale formation was considered to study salinity effects. Results show that shear and tensile failure can occur around a wellbore in certain drilling conditions where the mud pressure lies between the reservoir pore pressure and fracture gradient. The fully coupled thermo-poro-mechanical FEM simulation was used to model damage/fracture propagation and microseismic events caused by fluid injection. These studies considered wellbore geometry in small-scale modeling and point-source injection, assuming singularity fluid flux for large-scale simulation. Damage mechanics was applied to capture the effects of crack initiation, microvoid growth, and fracture propagation. The induced microseismic events were modeled in heterogeneous geological media, assuming the Weibull distribution functions for modulus and permeability. The results of this study indicate that fluid injection causes the effective stress to relax in the damage phase and to concentrate at the interface between the damage phase and the intact rock. Furthermore, induced-stress and far-field stress influence damage propagation. Cold water injection causes the tensile stress and affects the initial fracture and fracture propagation, but fracture initiation pressure and far-field stress are critical to create a damage/fracture plane, which is normal to the minimum far-field stress direction following well stimulation. Microseismic events propagate at both well scale and reservoir-scale simulation; the cloud shape of a microseismic event is affected by permeability anisotropy and far-field stress, and deviatoric horizontal far-field stress especially contributes to the localization of the microseismic cloud.

Lee, Sang Hoon

2011-12-01T23:59:59.000Z

412

Key computational modeling issues in Integrated Computational Materials Engineering  

Science Conference Proceedings (OSTI)

Designing materials for targeted performance requirements as required in Integrated Computational Materials Engineering (ICME) demands a combined strategy of bottom-up and top-down modeling and simulation which treats various levels of hierarchical material ... Keywords: Databases, ICME, Materials design, Multiscale modeling, Uncertainty

Jitesh H. Panchal; Surya R. Kalidindi; David L. Mcdowell

2013-01-01T23:59:59.000Z

413

SEISMIC AND ROCK PHYSICS DIAGNOSTICS OF MULTISCALE RESERVOIR TEXTURES  

Science Conference Proceedings (OSTI)

As part of our study on ''Relationships between seismic properties and rock microstructure'', we have (1) Studied relationships between velocity and permeability. (2) Used independent experimental methods to measure the elastic moduli of clay minerals as functions of pressure and saturation. (3) Applied different statistical methods for characterizing heterogeneity and textures from scanning acoustic microscope (SAM) images of shale microstructures. (4) Analyzed the directional dependence of velocity and attenuation in different reservoir rocks (5) Compared Vp measured under hydrostatic and non-hydrostatic stress conditions in sands. (6) Studied stratification as a source of intrinsic anisotropy in sediments using Vp and statistical methods for characterizing textures in sands.

Gary Mavko

2003-10-01T23:59:59.000Z

414

Multiscale Mountain Waves Influencing a Major Orographic Precipitation Event  

Science Conference Proceedings (OSTI)

This study combines high-resolution mesoscale model simulations and comprehensive airborne Doppler radar observations to identify kinematic structures influencing the production and mesoscale distribution of precipitation and microphysical ...

Matthew F. Garvert; Bradley Smull; Cliff Mass

2007-03-01T23:59:59.000Z

415

Towards multiscale simulation of moist flows with soundproof equations  

Science Conference Proceedings (OSTI)

This paper discusses incorporation of phase changes of the water substance that accompany moist atmospheric flows into the all-scale atmospheric model based on soundproof equations. Specific issue concerns developing a theoretical basis and ...

Marcin J. Kurowski; Wojciech W. Grabowski; Piotr K. Smolarkiewicz

416

A multiscale framework for Bayesian inference in elliptic problems  

E-Print Network (OSTI)

The Bayesian approach to inference problems provides a systematic way of updating prior knowledge with data. A likelihood function involving a forward model of the problem is used to incorporate data into a posterior ...

Parno, Matthew David

2011-01-01T23:59:59.000Z

417

Modeling of the Aging Viscoelastic Properties of Cement Paste Using Computational Methods  

E-Print Network (OSTI)

Modeling of the time-dependent behavior of cement paste has always been a difficulty. In the past, viscoelastic behavior of cementitious materials has been primarily attributed to the viscoelastic properties of C-S-H components. Recent experimental results show that C-S-H may not exhibit as much creep and relaxation as previously thought. This requires new consideration of different mechanisms leading to the viscoelastic behavior of cement paste. Thus the objective of this thesis is to build a computational model using finite element method to predict the viscoelastic behavior of cement paste, and using this model, virtual tests can be carried out to improve understanding of the mechanisms of viscoelastic behavior. The primary finding from this thesis is that the apparent viscoelastic behavior due to dissolution of load bearing phases is substantial. The dissolution process occurring during the hydration reaction can change the stress distribution inside cementitious materials, resulting in an apparent viscoelastic behavior of the whole cementitious materials. This finding requires new consideration of mechanisms of time-dependent behavior of cementitious materials regarding the dissolution process of cement paste.

Li, Xiaodan

2012-05-01T23:59:59.000Z

418

An Ensemble Multiscale Filter for Large Nonlinear Data Assimilation Problems  

Science Conference Proceedings (OSTI)

Operational data assimilation problems tend to be very large, both in terms of the number of unknowns to be estimated and the number of measurements to be processed. This poses significant computational challenges, especially for ensemble methods,...

Yuhua Zhou; Dennis McLaughlin; Dara Entekhabi; Gene-Hua Crystal Ng

2008-02-01T23:59:59.000Z

419

Performance of mesoscale modeling methods for predicting microstructure, mobility and rheology of charged suspensions.  

SciTech Connect

In this presentation we examine the accuracy and performance of a suite of discrete-element-modeling approaches to predicting equilibrium and dynamic rheological properties of polystyrene suspensions. What distinguishes each approach presented is the methodology of handling the solvent hydrodynamics. Specifically, we compare stochastic rotation dynamics (SRD), fast lubrication dynamics (FLD) and dissipative particle dynamics (DPD). Method-to-method comparisons are made as well as comparisons with experimental data. Quantities examined are equilibrium structure properties (e.g. pair-distribution function), equilibrium dynamic properties (e.g. short- and long-time diffusivities), and dynamic response (e.g. steady shear viscosity). In all approaches we deploy the DLVO potential for colloid-colloid interactions. Comparisons are made over a range of volume fractions and salt concentrations. Our results reveal the utility of such methods for long-time diffusivity prediction can be dubious in certain ranges of volume fraction, and other discoveries regarding the best formulation to use in predicting rheological response.

Pierce, Flint; Grillet, Anne Mary; Grest, Gary Stephen; Lechman, Jeremy B.; Plimpton, Steven James; in't Veld, Pieter J. (BASF Corporation Ludwigshafen, Germany); Schunk, Peter Randall; Heine, D. R. (Corning, Inc. Corning, NY); Stoltz, C. (Procter and Gamble Co. West Chester, OH); Weiss, Horst (BASF Corporation Ludwigshafen, Germany); Jendrejack, R. (3M Corporation St. Paul, MN); Petersen, Matthew K.

2010-06-01T23:59:59.000Z

420

Eyelid and eyelash detection method in the normalized iris image using the parabolic Hough model and Otsu's thresholding method  

Science Conference Proceedings (OSTI)

Eyelids and eyelashes occluding the iris region are noise factors that degrade the performance of iris recognition. If they are incorrectly classified as an iris region, the false iris region information decreases the recognition rate. Thus, reliable ... Keywords: Eyelash detection, Eyelid detection, Iris recognition, Parabolic Hough model, Thresholding

Tae-Hong Min; Rae-Hong Park

2009-09-01T23:59:59.000Z

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


421

DIMENSION REDUCTION NUMERICAL CLOSURE METHOD FOR ADVECTION-DIFFUSION-REACTION SYSTEMS  

SciTech Connect

Many natural physical processes exhibit a multiscale behavior, that is the same processes allow different mathematical description on different scales. The microscale description is usually based on fundamental conservation laws that form a closed system of ordinary differential equations (ODEs) or partial differential equations (PDEs) but the numerical discretization of these equations may produce a system of ODEs with an enormous number of unknowns. Furthermore, a time integration of the microscale equations usually requires time steps that are smaller than the observation time by many orders of magnitude. A direct solution of these ODEs can be extremely expensive. This necessitates development of advanced algorithms for model (or dimension) reduction. Often, we are only interested in the average behavior of the system rather than the exact solution of the ODEs. Here we developed a novel dimension reduction method that gives an approximate solution of the ODEs and gives an accurate prediction of the average behavior. The method relies on a computational closure of averaged evolution balance equations. The computational closure is achieved via short bursts of microscale simulation. The dimension reduction model was used to simulate flow and transport with mixing controlled reactions and mineral precipitation. A pore-scale model was used as a microscale model. A good agreement between microscale simulations and the accelerated microscale simulations confirms the accuracy and computational efficiency of the dimension reduction model. The method significant accelerates microscale simulations, while providing accurate approximation of the solution and accurate prediction of the average behavior of the system.

Tartakovsky, Alexandre M.; Scheibe, Timothy D.

2011-11-30T23:59:59.000Z

422

Crude Oil Price Prediction Based On Multi-scale Decomposition  

Science Conference Proceedings (OSTI)

A synergetic model (DWT-LSSVM) is presented in this paper. First of all, the raw data is decomposed into approximate coefficients and the detail coefficients at different scales by discrete wavelet transforms (DWT). These coefficients obtained by previous ... Keywords: crude oil price, least squares vector machines, wavelet transform

Yejing Bao; Xun Zhang; Lean Yu; Shouyang Wang

2007-05-01T23:59:59.000Z

423

A Method for On-Going Commissioning of VRV Package Systems Using a Simulation Model  

E-Print Network (OSTI)

Variable refrigerant volume (VRV) systems, which have several indoor units and a single outdoor unit, have become very popular HVAC systems in Japan. However, some systems may be operated under inefficient conditions and consume excessive energy, since verification of system performance is not conducted. Although the performance of systems should be evaluated by some indices such as coefficient of performance (COP), calculating such a value is difficult, because the heat load handled by machines is not known. A simulation model based on a refrigeration cycle was proposed to evaluate system performance. Basic conditions for evaporation and condensation were defined from conditions provided in Japanese Industrial Standards (JIS). Flow rate of refrigerant was calculated from heat load under full occupancy and enthalpy difference of the evaporator. If power consumption exceeds the calculated value, malfunctions or inadequate conditions are considered to occur. The method presented here can be used for on-going commissioning of VRV package systems.

Yamaha, M.; Sekiyama, K.; Misaki, S.

2006-01-01T23:59:59.000Z

424

Model predictive control system and method for integrated gasification combined cycle power generation  

DOE Patents (OSTI)

Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

2013-04-09T23:59:59.000Z

425

Method Based on OSEK/VDX Platform Using Model-based and Autocode Technology for Diesel ECU Software Development  

Science Conference Proceedings (OSTI)

Recently, model-based and autocode technology has become mature and brings many advantages in automotive software development. In order to take advantage of these changes, organization must adjust development process. This paper proposes a "V+v" method, ...

MU Chunyang; SUN Lining; DU Zhijiang

2007-07-01T23:59:59.000Z

426

Data Assimilation in a Quasi-geostrophic Open-Ocean Model of the Gulf Stream Region Using the Adjoint Method  

Science Conference Proceedings (OSTI)

The method of adjoint data assimilation is applied in a quasi-geostrophic (QG) open-ocean model of the Gulf Stream region. The results of data assimilation experiments are presented in which simulated AXBT and satellite altimeter observations are ...

Andrew M. Moore

1991-03-01T23:59:59.000Z

427

Multidataset Study of Optimal Parameter and Uncertainty Estimation of a Land Surface Model with Bayesian Stochastic Inversion and Multicriteria Method  

Science Conference Proceedings (OSTI)

This study evaluates the ability of Bayesian stochastic inversion (BSI) and multicriteria (MC) methods to search for the optimal parameter sets of the Chameleon Surface Model (CHASM) using prescribed forcing to simulate observed sensible and ...

Youlong Xia; Mrinal K. Sen; Charles S. Jackson; Paul L. Stoffa

2004-10-01T23:59:59.000Z

428

Feasibility of the Direct Method to Solve the Anelastic Pressure Equation in Nonhydrostatic Two-Dimensional Mesoscale Models  

Science Conference Proceedings (OSTI)

For anelastic nonhydrostatic mesoscale models, the pressure has to be solved from the Poisson partial differential equation. This can be done in various ways. Here the usually neglected direct method is compared to widely used (iterative) ...

Antoon Meesters

1992-10-01T23:59:59.000Z

429

Development of New Ensemble Methods Based on the Performance Skills of Regional Climate Models over South Korea  

Science Conference Proceedings (OSTI)

In this paper, the prediction skills of five ensemble methods for temperature and precipitation are discussed by considering 20 yr of simulation results (from 1989 to 2008) for four regional climate models (RCMs) driven by NCEP–Department of ...

M.-S. Suh; S.-G. Oh; D.-K. Lee; D.-H. Cha; S.-J. Choi; C.-S. Jin; S.-Y. Hong

2012-10-01T23:59:59.000Z

430

A Method for Imposing Surface Stress and Heat Flux Conditions in Finite-Difference Models with Steep Terrain  

Science Conference Proceedings (OSTI)

A numerical implementation of the surface stress boundary condition is presented for finite-difference models in which the terrain slope and curvature cannot necessarily be considered small. The method involves reducing the discretized stress ...

C. C. Epifanio

2007-03-01T23:59:59.000Z

431

Assessment of methods for creating a national building statistics database for atmospheric dispersion modeling  

SciTech Connect

Mesoscale meteorological codes and transport and dispersion models are increasingly being applied in urban areas. Representing urban terrain characteristics in these models is critical for accurate predictions of air flow, heating and cooling, and airborne contaminant concentrations in cities. A key component of urban terrain characterization is the description of building morphology (e.g., height, plan area, frontal area) and derived properties (e.g., roughness length). Methods to determine building morphological statistics range from manual field surveys to automated processing of digital building databases. In order to improve the quality and consistency of mesoscale meteorological and atmospheric dispersion modeling, a national dataset of building morphological statistics is needed. Currently, due to the expense and logistics of conducting detailed field surveys, building statistics have been derived for only small sections of a few cities. In most other cities, modeling projects rely on building statistics estimated using intuition and best guesses. There has been increasing emphasis in recent years to derive building statistics using digital building data or other data sources as a proxy for those data. Although there is a current expansion in public and private sector development of digital building data, at present there is insufficient data to derive a national building statistics database using automated analysis tools. Too many cities lack digital data on building footprints and heights and many of the cities having such data do so for only small areas. Due to the lack of sufficient digital building data, other datasets are used to estimate building statistics. Land use often serves as means to provide building statistics for a model domain, but the strength and consistency of the relationship between land use and building morphology is largely uncertain. In this paper, we investigate whether building statistics can be correlated to the underlying land use. If a reasonable correlation exists, then a national building statistics database could be created since land use is available for the entire U.S. Digital datasets of building footprint and height information have been obtained, validated and analyzed for eight western U.S. cities covering areas ranging from 6 km{sup 2} to 1653 km{sup 2}. Building morphological statistics (including mean and standard deviation of building height, plan area fraction and density, rooftop area density, frontal area index and density, building-to-plan area ratio, complete aspect ratio, height-to-width ratio, roughness length, displacement height, and sky view factor) have been computed for each city at 250-m resolution and are being correlated to underlying land use type. This paper will summarize the building statistics from the eight cites focusing on the variability within each city and between cities as a function of land use.

Velugubantla, S. P. (Srinivas, P.); Burian, S. J. (Steven J.); Brown, M. J. (Michael J.); McKinnon, A. T. (Andrew T.); McPherson, T. N. (Timothy N.); Han, W. S. (Woo Suk)

2004-01-01T23:59:59.000Z

432

REVIEW OF MECHANISTIC UNDERSTANDING AND MODELING AND UNCERTAINTY ANALYSIS METHODS FOR PREDICTING CEMENTITIOUS BARRIER PERFORMANCE  

SciTech Connect

Cementitious barriers for nuclear applications are one of the primary controls for preventing or limiting radionuclide release into the environment. At the present time, performance and risk assessments do not fully incorporate the effectiveness of engineered barriers because the processes that influence performance are coupled and complicated. Better understanding the behavior of cementitious barriers is necessary to evaluate and improve the design of materials and structures used for radioactive waste containment, life extension of current nuclear facilities, and design of future nuclear facilities, including those needed for nuclear fuel storage and processing, nuclear power production and waste management. The focus of the Cementitious Barriers Partnership (CBP) literature review is to document the current level of knowledge with respect to: (1) mechanisms and processes that directly influence the performance of cementitious materials (2) methodologies for modeling the performance of these mechanisms and processes and (3) approaches to addressing and quantifying uncertainties associated with performance predictions. This will serve as an important reference document for the professional community responsible for the design and performance assessment of cementitious materials in nuclear applications. This review also provides a multi-disciplinary foundation for identification, research, development and demonstration of improvements in conceptual understanding, measurements and performance modeling that would be lead to significant reductions in the uncertainties and improved confidence in the estimating the long-term performance of cementitious materials in nuclear applications. This report identifies: (1) technology gaps that may be filled by the CBP project and also (2) information and computational methods that are in currently being applied in related fields but have not yet been incorporated into performance assessments of cementitious barriers. The various chapters contain both a description of the mechanism or and a discussion of the current approaches to modeling the phenomena.

Langton, C.; Kosson, D.

2009-11-30T23:59:59.000Z

433

Multi-Scale, Sustainable Reaction Engineering - A New Departmental Initiative  

E-Print Network (OSTI)

but it remains a continuing strength for the Department, underpinned by many new developments Illustration by Current/ Future Research Reactor and Reaction Efficiency Sustainable Energy Generation Transport Biofuels Modelling Reactor and Reaction... from Biomass via Iron Oxide Looping Dennis & Scott (2006). A.I.Ch.E.J., 52, 3325-3328. EPSRC Grant EP/F027435/1. Transport Biofuels Biomass Conversion to Fuel - Issues Options (i) gasification/GTL (ii) hydrolysis/fermentation Need...

Dennis, John

2008-07-29T23:59:59.000Z

434

Development of a Multiscale Ionized Gas (MIG) Flow Code for Plasma Applications Subrata Roy Datta V. Gaitonde  

E-Print Network (OSTI)

dynamics, electromagnetics, chemical kinetics and molecular physics amongst others. A finite element basedDevelopment of a Multiscale Ionized Gas (MIG) Flow Code for Plasma Applications Subrata Roy Datta V applications including space propulsion thrusters and high-speed air vehicles. These are of considerable

Roy, Subrata

435

Propagation of radiation in fluctuating multiscale plasmas. II. Kinetic simulations  

Science Conference Proceedings (OSTI)

A numerical algorithm is developed and tested that implements the kinetic treatment of electromagnetic radiation propagating through plasmas whose properties have small scale fluctuations, which was developed in a companion paper. This method incorporates the effects of refraction, damping, mode structure, and other aspects of large-scale propagation of electromagnetic waves on the distribution function of quanta in position and wave vector, with small-scale effects of nonuniformities, including scattering and mode conversion approximated as causing drift and diffusion in wave vector. Numerical solution of the kinetic equation yields the distribution function of radiation quanta in space, time, and wave vector. Simulations verify the convergence, accuracy, and speed of the methods used to treat each term in the equation. The simulations also illustrate the main physical effects and place the results in a form that can be used in future applications.

Pal Singh, Kunwar; Robinson, P. A.; Cairns, Iver H.; Tyshetskiy, Yu. [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

2012-11-15T23:59:59.000Z

436

Stable Multiscale Bases and Local Error Estimation for Elliptic Problems  

E-Print Network (OSTI)

methods to accelerate the search, can form practical algorithms for rigorously finding all roots at such points in the second problem. nle-1 This one-dimensional problem is given by f(x) = |x2 + 5x| + x + 1 = 0. Its roots are at x = -2 - 5 [-4.237, -4.236] and x = -3 - 8 [-5.829, -5.828]. nle-2 This two

Dahlke, Stephan

437

Implementation of the Semi-Lagrangian Method in a High-Resolution Version of the ECMWF Forecast Model  

Science Conference Proceedings (OSTI)

In this article the implementation of the semi-Lagrangian method in a high-resolution version of the ECMWF forecast model is examined. Novel aspects include the application of the semi-Lagrangian scheme to a global model using the ECMWF hybrid ...

Harold Ritchie; Clive Temperton; Adrian Simmons; Mariano Hortal; Terry Davies; David Dent; Mats Hamrud

1995-02-01T23:59:59.000Z

438

Integrating complementarity into the 2D displacement discontinuity boundary element method to model faults and fractures with frictional contact properties  

Science Conference Proceedings (OSTI)

We present a two-dimensional displacement discontinuity method (DDM) in combination with a complementarity solver to simulate quasi-static slip on cracks as models for faults and fractures in an otherwise homogeneous, isotropic, linear elastic material. ... Keywords: Boundary element model, Complementarity, Friction, Frictional strength

Elizabeth Ritz; Ovunc Mutlu; David D. Pollard

2012-08-01T23:59:59.000Z

439

Original article: Estimation of spatially varying open boundary conditions for a numerical internal tidal model with adjoint method  

Science Conference Proceedings (OSTI)

The adjoint data assimilation technique is applied to the estimation of the spatially varying open boundary conditions (OBCs) for a numerical internal tidal model. The spatial variation of the OBCs is realized by the so-called 'independent point scheme' ... Keywords: Adjoint method, Internal tidal model, Open boundary conditions, Parameter estimation, Spatial variation

Haibo Chen, Anzhou Cao, Jicai Zhang, Chunbao Miao, Xianqing Lv

2014-03-01T23:59:59.000Z

440

A novel method for testing normality in a mixed model of a nested classification  

Science Conference Proceedings (OSTI)

Normality is one of the most common assumptions made in the development of statistical models such as the fixed effect model and the random effect model. White and MacDonald [1980. Some large-sample tests for normality in the linear regression model. ... Keywords: Normality test, Random effect model, Shapiro-Wilk test, Simulations, Skewness test, Transformation

Yi-Ting Hwang; Peir Feng Wei

2006-11-01T23:59:59.000Z

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


441

Natural Tracers and Multi-Scale Assessment of Caprock Sealing Behavior: A Case Study of the Kirtland Formation, San Juan Basin  

Science Conference Proceedings (OSTI)

The assessment of caprocks for geologic CO{sub 2} storage is a multi-scale endeavor. Investigation of a regional caprock - the Kirtland Formation, San Juan Basin, USA - at the pore-network scale indicates high capillary sealing capacity and low permeabilities. Core and wellscale data, however, indicate a potential seal bypass system as evidenced by multiple mineralized fractures and methane gas saturations within the caprock. Our interpretation of {sup 4}He concentrations, measured at the top and bottom of the caprock, suggests low fluid fluxes through the caprock: (1) Of the total {sup 4}He produced in situ (i.e., at the locations of sampling) by uranium and thorium decay since deposition of the Kirtland Formation, a large portion still resides in the pore fluids. (2) Simple advection-only and advection-diffusion models, using the measured {sup 4}He concentrations, indicate low permeability ({approx}10-20 m{sup 2} or lower) for the thickness of the Kirtland Formation. These findings, however, do not guarantee the lack of a large-scale bypass system. The measured data, located near the boundary conditions of the models (i.e., the overlying and underlying aquifers), limit our testing of conceptual models and the sensitivity of model parameterization. Thus, we suggest approaches for future studies to better assess the presence or lack of a seal bypass system at this particular site and for other sites in general.

Jason Heath; Brian McPherson; Thomas Dewers

2011-03-15T23:59:59.000Z

442

A Comparison of Data Assimilation Methods Using a Planetary Geostrophic Model  

Science Conference Proceedings (OSTI)

Assimilating hydrographic observations into a planetary geostrophic model is posed as a problem in control theory. The cost functional is the sum of weighted model and data residuals. Model errors are assumed to be spatially correlated, and ...

Edward D. Zaron

2006-04-01T23:59:59.000Z

443

Seismic and Rockphysics Diagnostics of Multiscale Reservoir Textures  

SciTech Connect

This final technical report summarizes the results of the work done in this project. The main objective was to quantify rock microstructures and their effects in terms of elastic impedances in order to quantify the seismic signatures of microstructures. Acoustic microscopy and ultrasonic measurements were used to quantify microstructures and their effects on elastic impedances in sands and shales. The project led to the development of technologies for quantitatively interpreting rock microstructure images, understanding the effects of sorting, compaction and stratification in sediments, and linking elastic data with geologic models to estimate reservoir properties. For the public, ultimately, better technologies for reservoir characterization translates to better reservoir development, reduced risks, and hence reduced energy costs.

Gary Mavko

2005-07-01T23:59:59.000Z

444

Evaluation of metal artifacts in MVCT systems using a model based correction method  

Science Conference Proceedings (OSTI)

Purpose: To evaluate the performance of a model based image reconstruction method in reducing metal artifacts in the megavoltage computed tomography (MVCT) images of a phantom representing bilateral hip prostheses and to compare with the filtered-backprojection (FBP) technique. Methods: An iterative maximum likelihood polychromatic algorithm for CT (IMPACT) is used with an additional model for the pair/triplet production process and the energy dependent response of the detectors. The beam spectra for an in-house bench-top and TomoTherapy Trade-Mark-Sign MVCTs are modeled for use in IMPACT. The empirical energy dependent response of detectors is calculated using a constrained optimization technique that predicts the measured attenuation of the beam by various thicknesses (0-24 cm) of solid water slabs. A cylindrical (19.1 cm diameter) plexiglass phantom containing various cylindrical inserts of relative electron densities 0.295-1.695 positioned between two steel rods (2.7 cm diameter) is scanned in the bench-top MVCT that utilizes the bremsstrahlung radiation from a 6 MeV electron beam passed through 4 cm solid water on the Varian Clinac 2300C and in the imaging beam of the TomoTherapy Trade-Mark-Sign MVCT. The FBP technique in bench-top MVCT reconstructs images from raw signal normalized to air scan and corrected for beam hardening using a uniform plexiglass cylinder (20 cm diameter). The IMPACT starts with a FBP reconstructed seed image and reconstructs the final image in 150 iterations. Results: In both MVCTs, FBP produces visible dark shading in the image connecting the steel rods. In the IMPACT reconstructed images this shading is nearly removed and the uniform background is restored. The average attenuation coefficients of the inserts and the background are very close to the corresponding values in the absence of the steel inserts. In the FBP images of the bench-top MVCT, the shading causes 4%-9.5% underestimation of electron density at the central inserts with an average of (6.3 {+-} 1.8)% for the range of electron densities studied. In the uniform plexiglass background, the shadow creates 0.8%-4.7% underestimation of electron density with an average of (2.9 {+-} 1.2)%. In the corresponding IMPACT images, the underestimation in the shaded plexiglass background is 0.3%-1.8% with an average of (0.9 {+-} 0.5)% and 1.4%-6.8% with an average of (2.8 {+-} 2.7)% in the central insert region. In the FBP images of the TomoTherapy Trade-Mark-Sign MVCT, this shading creates 2.6%-6.7% underestimation of electron density with an average of (3.7 {+-} 1.4)% at the central inserts and 5.9%-7.2% underestimation in the background with an average of (6.4 {+-} 0.5)%. In the IMPACT images, the uniform background between the steel rods is restored with 0.3%-1.0% underestimation of electron density with an average of (0.7 {+-} 0.3)%. The corresponding underestimation at the central inserts of the IMPACT images is -0.4%-0.1% with an average of (-0.1 {+-} 0.2)%. Conclusions: The shading metal artifact has been nearly removed in MVCT images using the IMPACT algorithm with the accurate geometry of the system, proper modeling of energy dependent response of detectors, and all relevant photon interaction processes. This results less than 1% difference in electron density in the background plexiglass and less than 3% averaged over the range of electron densities investigated.

Paudel, M. R.; Mackenzie, M.; Fallone, B. G.; Rathee, S. [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

2012-10-15T23:59:59.000Z

445

Analysis of the semianalytical method for matching aquifer influence functions using an analytical model  

E-Print Network (OSTI)

For a heterogeneous aquifer of unknown size and shape, ics. Aquifer Influence Functions (AIF) can be used to model the aquifer pressure behavior from field production and pressure data. Two methods have been used in the past to accomplish this, namely Linear Programming (LP) and the Semianalytical technique. The latter is based on the analytical solution form of a heterogeneous aquifer of any size and shape. The approximating AIF is a continuous function, which is a truncated series of the exact analytical solution. This Semianalytical function is fitted to field data by the use of nonlinear least squares fitting. It has the advantages over the LP method that it is much faster, uses less computer space, and does not require evenly spaced production periods. For the cases in which the OGIP is unknown, a technique was proposed in the past in which the term Relative Error is defined. Several values of OGIP are assumed, and the one that yields the minimum Relative Error is the actual or optimum value of OGIP. Because of the nonlinear nature of the optimization procedure, when the Semianalytical technique is used along with the Relative Error technique, it tends to be caught in the so-called local minima, which lead to the determination of spurious values of the AIF and the optimum OGIP. Both the LP and the Semianalytical techniques have been validated using field data. However, when the latter is used, weird variations of the Relative Error function, and unrealistically low values of the optimum OGIP are observed. A simple analytical model is used in this project. It allows the generation of synthetic data. The objective is to use those as input data to the Semianalytical and Relative Error techniques and determine their effectiveness to determine the AIF and the optimum OGIP which are known in advance. A modification is proposed in the current research to prevent the nonlinear regression from getting caught in the local minima. After this goal is attained, typical features in the normalized Relative Error and allows the determination of the drive mechanism and the OGIP even in gas reservoirs whose histories are so brief that the use of the p/Z technique becomes prohibitive.

Vega, Leonardo

1998-01-01T23:59:59.000Z

446

Modeling Aspects and Computational Methods for Some Recent Problems of Tomographic Imaging  

E-Print Network (OSTI)

In this dissertation, two recent problems from tomographic imaging are studied, and results from numerical simulations with synthetic data are presented. The first part deals with ultrasound modulated optical tomography, a method for imaging interior optical properties of partially translucent media that combines optical contrast with ultrasound resolution. The primary application is the optical imaging of soft tissue, for which scattering and absorption rates contain important functional and structural information about the physiological state of tissue cells. We developed a mathematical model based on the diffusion approximation for photon propagation in highly scattering media. Simple reconstruction schemes for recovering optical absorption rates from boundary measurements with focused ultrasound are presented. We show numerical reconstructions from synthetic data generated for mathematical absorption phantoms. The results indicate that high resolution imaging with quantitatively correct values of absorption is possible. Synthetic focusing techniques are suggested that allow reconstruction from measurements with certain types of non-focused ultrasound signals. A preliminary stability analysis for a linearized model is given that provides an initial explanation for the observed stability of reconstruction. In the second part, backprojection schemes are proposed for the detection of small amounts of highly enriched nuclear material inside 3D volumes. These schemes rely on the geometrically singular structure that small radioactive sources represent, compared to natural background radiation. The details of the detection problem are explained, and two types of measurements, collimated and Compton-type measurements, are discussed. Computationally, we implemented backprojection by counting the number of particle trajectories intersecting each voxel of a regular rectangular grid covering the domain of detection. For collimated measurements, we derived confidence estimates indicating when voxel trajectory counts are deviating significantly from what is expected from background radiation. Monte Carlo simulations of random background radiation confirm the estimated confidence values. Numerical results for backprojection applied to synthetic measurements are shown that indicate that small sources can be detected for signal-to-noise ratios as low as 0.1%.

Allmaras, Moritz

2011-12-01T23:59:59.000Z

447

A Multi-Methods Approach to HRA and Human Performance Modeling: A Field Assessment  

SciTech Connect

The Advanced Test Reactor (ATR) is a research reactor at the Idaho National Laboratory is primarily designed and used to test materials to be used in other, larger-scale and prototype reactors. The reactor offers various specialized systems and allows certain experiments to be run at their own temperature and pressure. The ATR Canal temporarily stores completed experiments and used fuel. It also has facilities to conduct underwater operations such as experiment examination or removal. In reviewing the ATR safety basis, a number of concerns were identified involving the ATR canal. A brief study identified ergonomic issues involving the manual handling of fuel elements in the canal that may increase the probability of human error and possible unwanted acute physical outcomes to the operator. In response to this concern, that refined the previous HRA scoping analysis by determining the probability of the inadvertent exposure of a fuel element to the air during fuel movement and inspection was conducted. The HRA analysis employed the SPAR-H method and was supplemented by information gained from a detailed analysis of the fuel inspection and transfer tasks. This latter analysis included ergonomics, work cycles, task duration, and workload imposed by tool and workplace characteristics, personal protective clothing, and operational practices that have the potential to increase physical and mental workload. Part of this analysis consisted of NASA-TLX analyses, combined with operational sequence analysis, computational human performance analysis (CHPA), and 3D graphical modeling to determine task failures and precursors to such failures that have safety implications. Experience in applying multiple analysis techniques in support of HRA methods is discussed.

Jacques Hugo; David I Gertman

2012-06-01T23:59:59.000Z

448

A Community Atmosphere Model with Superparameterized Clouds  

SciTech Connect

In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.

Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim

2013-06-18T23:59:59.000Z

449

Mesoscale Convective Vortices in Multiscale, Idealized Simulations: Dependence on Background State, Interdependency with Moist Baroclinic Cyclones, and Comparison with BAMEX Observations  

Science Conference Proceedings (OSTI)

A set of multiscale, nested, idealized numerical simulations of mesoscale convective systems (MCSs) and mesoscale convective vortices (MCVs) was conducted. The purpose of these simulations was to investigate the dependence of MCV development and ...

Robert J. Conzemius; Michael T. Montgomery

2010-04-01T23:59:59.000Z

450

A Hybrid MPI–OpenMP Parallel Algorithm and Performance Analysis for an Ensemble Square Root Filter Designed for Multiscale Observations  

Science Conference Proceedings (OSTI)

A hybrid parallel scheme for the ensemble square root filter (EnSRF) suitable for parallel assimilation of multiscale observations, including those from dense observational networks such as those of radar, is developed based on the domain ...

Yunheng Wang; Youngsun Jung; Timothy A. Supinie; Ming Xue

2013-07-01T23:59:59.000Z

451

Isomorph-free model enumeration: a new method for checking relational specifications  

Science Conference Proceedings (OSTI)

Software specifications often involve data structures with huge numbers of value, and consequently they cannot be checked using standard state exploration or model-checking techniques. Data structures can be expressed with binary relations, and operations ... Keywords: formal specification, model checking, model finding, object models, pruning, relational calculus, relational specifications, symmetry

Daniel Jackson; Somesh Jha; Craig A. Damon

1998-03-01T23:59:59.000Z

452

Nonconforming cell boundary element methods for elliptic problems on triangular mesh  

Science Conference Proceedings (OSTI)

The nonconforming cell boundary element (CBE) methods are proposed. The methods are designed in such a way that they enjoy the mass conservation at the element level and the normal component of fluxes at inter-element boundaries are continuous for unstructured ... Keywords: Multiscale method, 65N12, 65N30, Cell boundary element method, Finite volume, Flux conservation, Mixed finite element, Nonconforming finite element

Youngmok Jeon; Eun-Jae Park

2008-06-01T23:59:59.000Z

453

A Warm-Bin–Cold-Bulk Hybrid Cloud Microphysical Model  

Science Conference Proceedings (OSTI)

This study describes a newly developed bin–bulk hybrid cloud microphysical model named MSSG-Bin, which has been implemented in the Multi-Scale Simulator for the Geoenvironment (MSSG). In the hybrid approach, a spectral bin scheme is used for ...

Ryo Onishi; Keiko Takahashi

2012-05-01T23:59:59.000Z

454

Multi-level agent-based modeling - Bibliography  

E-Print Network (OSTI)

This very short article aims to bring together the available bibliography on multi-level (or multi-layer, multi-perspective, multi-view, multi-scale, multi-resolution) agent-based modeling so that it is accessible to interested researchers.

Morvan, Gildas

2012-01-01T23:59:59.000Z

455

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

E-Print Network (OSTI)

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

Taycher, Leonid

2006-01-01T23:59:59.000Z

456

Spatial Superposition Method via Model Coupling for Urban Heat Island Albedo Mitigation Strategies  

Science Conference Proceedings (OSTI)

A spatial superposition design is presented that couples the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) with the National Center of Excellence (NCE) lumped urban thermal model for ...

Humberto Silva III; Jay S. Golden

2012-11-01T23:59:59.000Z

457

The robust estimation method for a finite mixture of Poisson mixed-effect models  

Science Conference Proceedings (OSTI)

When analyzing clustered count data derived from several latent subpopulations, the finite mixture of the Poisson mixed-effect model is an immediate strategy to model the underlying heterogeneity. Within the generalized linear mixed model framework, ... Keywords: Finite mixture, Minimum Hellinger distance, Non-parametric maximum likelihood, Robustness

Liming Xiang; Kelvin K. W. Yau; Andy H. Lee

2012-06-01T23:59:59.000Z

458

Modeling of Emission Signatures of Massive Black Hole Binaries: I Methods  

E-Print Network (OSTI)

We model the electromagnetic signatures of massive black hole binaries (MBHBs) with an associated gas component. The method comprises numerical simulations of relativistic binaries and gas coupled with calculations of the physical properties of the emitting gas. We calculate the UV/X-ray and the Halpha light curves and the Halpha emission profiles. The simulations are carried out with a modified version of the parallel tree SPH code Gadget. The heating, cooling, and radiative processes are calculated for two different physical scenarios, where the gas is approximated as a black-body or a solar metallicity gas. The calculation for the solar metallicity scenario is carried out with the photoionization code Cloudy. We focus on sub-parsec binaries which have not yet entered the gravitational radiation phase. The results from the first set of calculations, carried out for a coplanar binary and gas disk, suggest that there are pronounced outbursts in the X-ray light curve during pericentric passages. If such outbursts persist for a large fraction of the lifetime of the system, they can serve as an indicator of this type of binary. The predicted Halpha emission line profiles may be used as a criterion for selection of MBHB candidates from existing archival data. The orbital period and mass ratio of a binary may be inferred after carefully monitoring the evolution of the Halpha profiles of the candidates. The discovery of sub-parsec binaries is an important step in understanding of the merger rates of MBHBs and their evolution towards the detectable gravitational wave window.

Tamara Bogdanovic; Britton D. Smith; Steinn Sigurdsson; Michael Eracleous

2007-08-02T23:59:59.000Z

459

Spectral-Lagrangian methods for collisional models of non-equilibrium statistical states  

Science Conference Proceedings (OSTI)

We propose a new spectral Lagrangian based deterministic solver for the non-linear Boltzmann transport equation (BTE) in d-dimensions for variable hard sphere (VHS) collision kernels with conservative or non-conservative binary interactions. The method ... Keywords: Boltzmann transport equation, Conservative/non-conservative deterministic method, FFT, Lagrangian optimization, Spectral method

Irene M. Gamba; Sri Harsha Tharkabhushanam

2009-04-01T23:59:59.000Z

460

Modeling of wire-on-tube heat exchangers using finite element method  

Science Conference Proceedings (OSTI)

Wire-on-tube heat exchangers are analysed under normal operating conditions (free convection) using finite element method. Galerkin's weighted residual method is used to minimise the errors. The effects of ambient temperatures and mass flow rates of ... Keywords: finite element method, free convection, phase change, wire on-tube heat exchangers

G. A. Quadir; G. M. Krishnan; K. N. Seetharamu

2002-03-01T23:59:59.000Z

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


461

Study of the validity of a combined potential model using the hybrid reverse Monte Carlo method in fluoride glass system  

E-Print Network (OSTI)

The choice of appropriate interaction models is among the major disadvantages of conventional methods such as molecular dynamics and Monte Carlo simulations. On the other hand, the so-called reverse Monte Carlo (RMC) method, based on experimental data, can be applied without any interatomic and/or intermolecular interactions. The RMC results are accompanied by artificial satellite peaks. To remedy this problem, we use an extension of the RMC algorithm, which introduces an energy penalty term into the acceptance criteria. This method is referred to as the hybrid reverse Monte Carlo (HRMC) method. The idea of this paper is to test the validity of a combined potential model of coulomb and Lennard-Jones in a fluoride glass system BaMnMF_{7} (M=Fe,V) using HRMC method. The results show a good agreement between experimental and calculated characteristics, as well as a meaningful improvement in partial pair distribution functions. We suggest that this model should be used in calculating the structural properties and in describing the average correlations between components of fluoride glass or a similar system. We also suggest that HRMC could be useful as a tool for testing the interaction potential models, as well as for conventional applications.

S. M. Mesli; M. Habchi; M. Kotbi; H. Xu

2013-03-25T23:59:59.000Z

462

Model-based performance monitoring: Review of diagnostic methods and chiller case study  

E-Print Network (OSTI)

and Salsbury 1997). Automation of FDD Current commissioningreference models used in FDD should treat dynamic behaviormodels can be used for FDD if it is possible to determine

Haves, Phil; Khalsa, Satkartar

2000-01-01T23:59:59.000Z

463

Modeling of Irradiation Hardening of Polycrystalline Materials  

Science Conference Proceedings (OSTI)

High energy particle irradiation of structural polycrystalline materials usually produces irradiation hardening and embrittlement. The development of predict capability for the influence of irradiation on mechanical behavior is very important in materials design for next generation reactors. In this work a multiscale approach was implemented to predict irradiation hardening of body centered cubic (bcc) alpha-iron. The effect of defect density, texture and grain boundary was investigated. In the microscale, dislocation dynamics models were used to predict the critical resolved shear stress from the evolution of local dislocation and defects. In the macroscale, a viscoplastic self-consistent model was applied to predict the irradiation hardening in samples with changes in texture and grain boundary. This multiscale modeling can guide performance evaluation of structural materials used in next generation nuclear reactors.

Li, Dongsheng; Zbib, Hussein M.; Garmestani, Hamid; Sun, Xin; Khaleel, Mohammad A.

2011-09-14T23:59:59.000Z

464

Stronger computational modelling of signalling pathways using both continuous and discrete-state methods  

E-Print Network (OSTI)

Calder,M. Duguid,A. Gilmore,S. Hillston,J. Computational Methods for Systems Biology, LNBI Vol. 4210 pp 63-78 Springer Verlag

Calder, M.

465

Comparing fixed and moving mesh methods for phase-field models  

Science Conference Proceedings (OSTI)

In this method, a minimum number of grid points is generally needed to .... Smart use of Density Functional Theory calculations to drive Newtonian dynamics.

466

Particle-in-cell modeling of relativistic laser-plasma interaction with the adjustable-damping, direct implicit method  

Science Conference Proceedings (OSTI)

Implicit particle-in-cell codes offer advantages over their explicit counterparts in that they suffer weaker stability constraints on the need to resolve the higher frequency modes of the system. This feature may prove particularly valuable for modeling ... Keywords: Implicit scheme, Laser-plasma interaction, Particle-in-cell method, Relativistic plasma

M. Drouin; L. Gremillet; J. -C. Adam; A. Héron

2010-06-01T23:59:59.000Z

467

Multi-Scale Modeling of Fission Gas Evolution in UO2  

Science Conference Proceedings (OSTI)

Fission gases in uranium dioxide (UO2) nuclear fuels, of which Xe is one of the most prominent, influence fuel performance during reactor operation and have ...

468

Simulated diurnal rainfall physics in a multi-scale global climate model with embedded explicit convection  

E-Print Network (OSTI)

layer destabilization to local solar heating and evapo-the daily cycle of solar heating excites many atmospherictrop- ics) and surface solar heating cycles are weak (over

Pritchard, Michael Stephen

2011-01-01T23:59:59.000Z

469

Modeling and Simulation of Electromutagenic Processes for Multiscale Modification of Concrete Jinko Kanno1  

E-Print Network (OSTI)

.1 Amperes per square foot. The electric field provides a targeted treatment that eventually could be applied a landmark study on the direct costs of corrosion in nearly every major U.S. industrial sector [1]. Corrosion in bridge structures is a global problem. The study found that the annual direct cost of highway bridge

Kanno,Jinko

470

Modeling of Multi-Scale Phenomena for Batteries - Programmaster.org  

Science Conference Proceedings (OSTI)

Ph: (865) 241-5145, Fax: (865) 574-4357; e-mail: sabaua@ornl.gov. Abstracts Due, 11/15/2009. Proceedings Plan, Definite: A CD-only volume ...

471

Factored Models for Multiscale Decision-Making in Smart Grid Customers Prashant P. Reddy  

E-Print Network (OSTI)

is an essential component of Turkish electricity reform. Yet, this tariff structure might create real hardship for residential tariffs. Conversely a number of taxes are presently levied on electricity consumers in provincial tariffs. Table 3 shows the provincial pattern of electricity expenditure and the proportion

Veloso, Manuela M.

472

Simulated diurnal rainfall physics in a multi-scale global climate model with embedded explicit convection  

E-Print Network (OSTI)

time of most westerly (offshore) winds is the end of thewind fluctuations over a distance of several hundred kilometers offshore

Pritchard, Michael Stephen

2011-01-01T23:59:59.000Z

473

PII-57: Multi-Scale Modeling of Ni/YSZ Fuel Cell Anode  

Science Conference Proceedings (OSTI)

Electrochemical reactions in a solid oxide fuel cell occur simultaneously as charge .... PII-66: Virtual Prototyping of Lightweight Designs Made with Cold and Hot ...

474

The Operational CMC–MRB Global Environmental Multiscale (GEM) Model. Part II: Results  

Science Conference Proceedings (OSTI)

An integrated forecasting and data assimilation system has been and is continuing to be developed by the Meteorological Research Branch (MRB) in partnership with the Canadian Meteorological Centre (CMC) of Environment Canada. Part II of this two-...

Jean Côté; Jean-Guy Desmarais; Sylvie Gravel; André Méthot; Alain Patoine; Michel Roch; Andrew Staniforth

1998-06-01T23:59:59.000Z

475

Multi-Scale Models of Crack Propagation and Their Use in ...  

Science Conference Proceedings (OSTI)

The rate of propagation is determined by fracture phenomena coupled over four ... scale, the microstructure of the material determines the resistance to fracture.

476

Simulated diurnal rainfall physics in a multi-scale global climate model with embedded explicit convection  

E-Print Network (OSTI)

waves, compensating subsidence and detrainment aroundunrealistic deep barotropic subsidence wave that otherwisethrough continuity) daytime subsidence over adjacent ocean.

Pritchard, Michael Stephen

2011-01-01T23:59:59.000Z

477

A generic multi-scale modeling framework for reactive observing systems: an overview  

Science Conference Proceedings (OSTI)

Observing systems facilitate scientific studies by instrumenting the real world and collecting corresponding measurements, with the aim of detecting and tracking phenomena of interest. A wide range of critical environmental monitoring objectives in resource ...

Leana Golubchik; David Caron; Abhimanyu Das; Amit Dhariwal; Ramesh Govindan; David Kempe; Carl Oberg; Abhishek Sharma; Beth Stauffer; Gaurav Sukhatme; Bin Zhang

2006-05-01T23:59:59.000Z

478

The Operational CMC–MRB Global Environmental Multiscale (GEM) Model. Part I: Design Considerations and Formulation  

Science Conference Proceedings (OSTI)

An integrated forecasting and data assimilation system has been and is continuing to be developed by the Meteorological Research Branch (MRB) in partnership with the Canadian Meteorological Centre (CMC) of Environment Canada. Part I of this two-...

Jean Côté; Sylvie Gravel; André Méthot; Alain Patoine; Michel Roch; Andrew Staniforth

1998-06-01T23:59:59.000Z

479

A9: Multiscale Modelling to Assess Elastic Properties of Cortical Bone  

Science Conference Proceedings (OSTI)

A8: Microstructural Investigation of Nano-Calcium Phosphates Doped with Fluoride Ions .... D7: Surfactant Structure–property Relationship: Effect of Polypropylene ... E4: The Effect of Monobutyl Ether Ethylene Glycol on the Conductivity and ...

480

Multi-scale modelling of III-nitrides: from dislocations to the electronic structure  

E-Print Network (OSTI)

in bulk . . . . . . . . . . . . . . . . . . . . . . . 28 2.3.3 Dislocation types near the free surface . . . . . . . . . . . . . . . . 31 2.4 Beyond linear elasticity – energy of the dislocation core . . . . . . . . . . 33 2.5 Summary... emitting blue light (? = 405 nm), more data (up to ? 25 GB) could be written on every single disk due to the shorter wavelength of the writing beam. Other exciting applications include solar cell arrays for satellites and power amplifiers at microwave...

Holec, David

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481

Global optimization method for combined spherical-cylindrical wrapping in musculoskeletal upper limb modelling  

Science Conference Proceedings (OSTI)

In musculoskeletal modelling, many muscles cannot be represented as straight lines from origin to insertion because the bony and musculotendinous morphology of neighboring structures causes them to wrap. The majority of these passive structures can be ... Keywords: Deltoid, Muscle wrapping, Musculoskeletal modelling

A. Audenaert; E. Audenaert

2008-10-01T23:59:59.000Z

482

Acoustic modeling problem for automatic speech recognition system: conventional methods (Part I)  

Science Conference Proceedings (OSTI)

In automatic speech recognition (ASR) systems, the speech signal is captured and parameterized at front end and evaluated at back end using the statistical framework of hidden Markov model (HMM). The performance of these systems depend critically on ... Keywords: ASR, Acoustic models, Back end, Front end, Gaussian mixtures, HMM

Rajesh Kumar Aggarwal; Mayank Dave

2011-12-01T23:59:59.000Z

483

Monte Carlo analysis of a new model-based method for insulin sensitivity testing  

Science Conference Proceedings (OSTI)

Insulin resistance (IR), or low insulin sensitivity, is a major risk factor in the pathogenesis of type 2 diabetes and cardiovascular disease. A simple, high resolution assessment of IR would enable earlier diagnosis and more accurate monitoring of intervention ... Keywords: Diabetes screening, Glucose modeling, Insulin modeling, Insulin resistance, Insulin sensitivity

Thomas F. Lotz; J.Geoffrey Chase; Kirsten A. McAuley; Geoffrey M. Shaw; Xing-Wei Wong; Jessica Lin; Aaron LeCompte; Christopher E. Hann; Jim I. Mann