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Office of Scientific and Technical Information
Computation of Domain-Averaged Irradiance with a Simple Two-Stream Radiative Transfer Model Including Vertical Cloud Property Correlations
NLE Websites -- All DOE Office Websites (Extended Search)
Computation of Domain-Averaged Irradiance Computation of Domain-Averaged Irradiance with a Simple Two-Stream Radiative Transfer Model Including Vertical Cloud Property Correlations S. Kato Center for Atmospheric Sciences Hampton University Hampton, Virginia Introduction Recent development of remote sensing instruments by Atmospheric Radiation Measurement (ARM?) Program provides information of spatial and temporal variability of cloud structures. However it is not clear what cloud properties are required to express complicated cloud fields in a realistic way and how to use them in a relatively simple one-dimensional (1D) radiative transfer model to compute the domain averaged irradiance. To address this issue, a simple shortwave radiative transfer model that can treat the vertical cloud optical property correlation is developed. The model is based on the gamma-weighted
Typologies of Computation and Computational Models
E-Print Network (OSTI)
We need much better understanding of information processing and computation as its primary form. Future progress of new computational devices capable of dealing with problems of big data, internet of things, semantic web, cognitive robotics and neuroinformatics depends on the adequate models of computation. In this article we first present the current state of the art through systematization of existing models and mechanisms, and outline basic structural framework of computation. We argue that defining computation as information processing, and given that there is no information without (physical) representation, the dynamics of information on the fundamental level is physical/ intrinsic/ natural computation. As a special case, intrinsic computation is used for designed computation in computing machinery. Intrinsic natural computation occurs on variety of levels of physical processes, containing the levels of computation of living organisms (including highly intelligent animals) as well as designed computational devices. The present article offers a typology of current models of computation and indicates future paths for the advancement of the field; both by the development of new computational models and by learning from nature how to better compute using different mechanisms of intrinsic computation.
Mark Burgin; Gordana Dodig-Crnkovic
Models of Procyon A including seismic constraints
Detailed models of Procyon A based on new asteroseismic measurements by Eggenberger et al (2004) have been computed using the Geneva evolution code including shellular rotation and atomic diffusion. By combining all non-asteroseismic observables now available for Procyon A with these seismological data, we find that the observed mean large spacing of 55.5 +- 0.5 uHz favours a mass of 1.497 M_sol for Procyon A. We also determine the following global parameters of Procyon A: an age of t=1.72 +- 0.30 Gyr, an initial helium mass fraction Y_i=0.290 +- 0.010, a nearly solar initial metallicity (Z/X)_i=0.0234 +- 0.0015 and a mixing-length parameter alpha=1.75 +- 0.40. Moreover, we show that the effects of rotation on the inner structure of the star may be revealed by asteroseismic observations if frequencies can be determined with a high precision. Existing seismological data of Procyon A are unfortunately not accurate enough to really test these differences in the input physics of our models.
P. Eggenberger; F. Carrier; F. Bouchy
Modeling tumor growth and irradiation response in vitro-a combination of high-performance computing and Web-based technologies including VRML visualization
Science Conference Proceedings (OSTI)
A simplified three-dimensional Monte Carlo simulation model of in vitro tumor growth and response to fractionated radiotherapeutic schemes is presented in this paper. The paper aims at both the optimization of radiotherapy and the provision of insight ...
G. S. Starnatakos; E. I. Zacharaki; M. Makropoulou; N. A. Mouravliansky; A. Marsh; K. S. Nikita; N. K. Uzunoglu
Quality Assurance of Computational Model
of Computational of Computational Models Presented at the Annual Department of Presented at the Annual Department of Energy Quality Council Meeting Subir K. Sen Sub . Se Office of Quality Assurance, HS-33 December 7, 2011 Outline Outline * Introduction Introduction * GAO Report 11-143 i l h C il * National Research Council Focus * DOE Model Validation/Performance * Summary 2 Introduction Introduction * Computer models are used in EM's massive Computer models are used in EM s massive clean up effort to model physical and biogeochemical processes biogeochemical processes. * Results from these computational models are often used to make costly cleanup decisions often used to make costly cleanup decisions including selection, performance assessment and annual
Computer cast blast modelling
SciTech Connect
Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC, applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the DMC can perform a blast simulation in 0.5 hours on the SUN SPARCstation 10--41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC computer. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.
Chung, S. [ICI Explosives Canada, North York, ON (Canada); McGill, M. [ICI Explosives USA, Dallas, TX (United States); Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States)
Ch. 33 Modeling: Computational Thermodynamics
This chapter considers methods and techniques for computational modeling for nuclear materials with a focus on fuels. The basic concepts for chemical thermodynamics are described and various current models for complex crystalline and liquid phases are illustrated. Also included are descriptions of available databases for use in chemical thermodynamic studies and commercial codes for performing complex equilibrium calculations.
Besmann, Theodore M [ORNL
High Performance Computing: Modeling & Simulation
High Performance Computing: Modeling & Simulation High Performance Computing: Modeling & Simulation Express Licensing Adaptive Real-Time Methodology for Optimizing Energy-Efficient...
Improved computer models support genetics research
Simple computer models unravel genetic stress reactions in cells Simple computer models unravel genetic stress reactions in cells Integrated biological and computational methods...
Computable General Equilibrium Models for Sustainability Impact...
Open Energy Info (EERE)
Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Jump to: navigation, search Name Computable General Equilibrium Models for...
February Simple computer models unravel genetic stress reactions in cells Simple computer models unravel genetic stress reactions in cells Integrated biological and...
Final technical report for DOE Computational Nanoscience Project: Integrated Multiscale Modeling of Molecular Computing Devices
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.
Diving decompression models and bubble metrics: Modern computer syntheses
A quantitative summary of computer models in diving applications is presented, underscoring dual phase dynamics and quantifying metrics in tissue and blood. Algorithms covered include the multitissue, diffusion, split phase gradient, linear-exponential, ... Keywords: Bubble metrics, Computer algorithms, Decompression models, Dive computers, Diver staging
B. R. Wienke
A Simple Model of Stratospheric Dynamics Including Solar Variability
A simple dynamic model, truncated from the stratospheric wave�zonal flow interaction Holton and Mass model, is introduced and studied. This model consists of three ordinary differential equations controlled by two parameters: the initial ...
Alexander Ruzmaikin; John Lawrence; Cristina Cadavid
NETL: Computer Software & Databases - Predictive Models
Predictive Models DOEBC-881SP. EOR Predictive Models: Handbook for Personal Computer Versions of Enhanced Oil Recovery Predictive Models. BPO Staff. February 1988. 76 pp. NTIS...
MODELING IN COMPUTATIONAL BIOLOGY. NOTES OF WEEK 9. 1. Fully Observed Markov Model: F. Sometimes we want to model a process of generating�...
Computer modeling of the Schottky electron source
A computer modeling program that is able to imitate the polyhedral shape of the ZrO/W(100) Schottky cathode is used to compute emission parameters such as the electric field distribution and reduced brightness Br for the various observed end form shapes. This program includes the electron�electron interactions in the beam and their effect on Br. A relationship between the axial field factor ??=?F/Ve and the axial lens factor K?=?(I?/J)1/2 (where F
Lynwood W. Swanson; Gregory A. Schwind; Sean M. Kellogg; Kun Liu
A security model for distributed computing
This paper presents a multi-tier model for secure computing as a teaching method platform. The security model is based on establishing the trustworthiness and role of each component in a distributed computing environment: trusted users, trusted servers, ...
Iliya K. Georgiev; Ivo I. Georgiev
Quantum computation beyond the circuit model
The quantum circuit model is the most widely used model of quantum computation. It provides both a framework for formulating quantum algorithms and an architecture for the physical construction of quantum computers. However, ...
Jordan, Stephen Paul
Computational Modeling of Organizations Comes of Age
As they are maturing�i.e., as they are becoming validated, calibrated and refined�computational emulation models of organizations are evolving into: powerful new kinds of organizational design tools for predicting and mitigating organizational ... Keywords: Virtual Design Team, computational modeling and simulation, computational modeling in engineering, computational modeling in natural science, industrial application, organizational engineering, state-of-the-art, synthetic experiments, validation
Raymond E. Levitt
Including model uncertainty in risk-informed decision-making
Model uncertainties can have a significant impact on decisions regarding licensing basis changes. We present a methodology to identify basic events in the risk assessment that have the potential to change the decision and ...
Reinert, Joshua M
MHK Reference Model: Relevance to Computer Simulation
July 9 th , 2012 SAND Number: 2012-5508P MHK Reference Model: Relevance to Computer Simulation Reference Model Partners Oregon State University NNMREC University of...
Modeling resource-coupled computations
Increasingly massive datasets produced by simulations beg the question How will we connect this data to the computational and display resources that support visualization and analysis? This question is driving research into new approaches to allocating ... Keywords: coupled computations, data intensive computing, high-performance computing, simulation
Mark Hereld; Joseph A. Insley; Eric C. Olson; Michael E. Papka; Thomas D. Uram; Venkatram Vishwanath
Efficient algorithms for new computational models
Advances in hardware design and manufacturing often lead to new ways in which problems can be solved computationally. In this thesis we explore fundamental problems in three computational models that are based on such ...
Ruhl, Jan Matthias, 1973-
Drainage Flow Prediction with a One-Dimensional Model Including Canopy, Soil and Radiation Parameterizations
A mathematical model for simulation of winds over mountain slopes was developed and tested withobservations from Australia and the western United States. The model computes profiles of wind andtemperature normal to the slope. The model also ...
Alfred J. Garrett
Accounting for the Energy Consumption of Personal Computing Including Portable Devices
the impact of energy consumed by the computing sector on the environment, as well as on the electricity cost Energy, Electricity, Computing, Portable Devices, Environment, Networking 1. INTRODUCTION The increasing, and what we can expect in the future. This requires a detailed analysis of energy consumption
Namboodiri, Vinod
Accounting for the energy consumption of personal computing including portable devices
In light of the increased awareness of global energy consumption, questions are also being asked about the contribution of computing equipment. Though studies have documented the share of energy consumption due to these equipment over the years, these ... Keywords: computing, electricity, energy, environment, networking, portable devices
Pavel Somavat; Shraddha Jadhav; Vinod Namboodiri
Cupola Furnace Computer Process Model
The cupola furnace generates more than 50% of the liquid iron used to produce the 9+ million tons of castings annually. The cupola converts iron and steel into cast iron. The main advantages of the cupola furnace are lower energy costs than those of competing furnaces (electric) and the ability to melt less expensive metallic scrap than the competing furnaces. However the chemical and physical processes that take place in the cupola furnace are highly complex making it difficult to operate the furnace in optimal fashion. The results are low energy efficiency and poor recovery of important and expensive alloy elements due to oxidation. Between 1990 and 2004 under the auspices of the Department of Energy, the American Foundry Society and General Motors Corp. a computer simulation of the cupola furnace was developed that accurately describes the complex behavior of the furnace. When provided with the furnace input conditions the model provides accurate values of the output conditions in a matter of seconds. It also provides key diagnostics. Using clues from the diagnostics a trained specialist can infer changes in the operation that will move the system toward higher efficiency. Repeating the process in an iterative fashion leads to near optimum operating conditions with just a few iterations. More advanced uses of the program have been examined. The program is currently being combined with an ''Expert System'' to permit optimization in real time. The program has been combined with ''neural network'' programs to affect very easy scanning of a wide range of furnace operation. Rudimentary efforts were successfully made to operate the furnace using a computer. References to these more advanced systems will be found in the ''Cupola Handbook''. Chapter 27, American Foundry Society, Des Plaines, IL (1999).
Seymour Katz
Computing Models for FPGA-Based Accelerators
Field-programmable gate arrays are widely considered accelerators for compute-intensive applications. A critical phase of FPGA application development is finding and mapping to the appropriate computing model. These models differ from models generally used in programming. For example
Martin C. Herbordt; Yongfeng Gu; Tom VanCourt; Josh Model; Bharat Sukhwani; Matt Chiu
Computational Modeling of Defect Evolution under Irradiation
Mar 14, 2012 ... Radiation Effects in Ceramic Oxide and Novel LWR Fuels: Computational Modeling of Defect Evolution under Irradiation Sponsored by: The�...
Computer Model Addresses Softening Steel Problem - Materials ...
Apr 22, 2013 ... Computer modeling, coupled with experiments, at Sandia National Laboratories has enabled the rapid design of an annealing process to�...
PI-23: Multiscale Computational Modeling of Adsorption
Presentation Title, PI-23: Multiscale Computational Modeling of Adsorption ... catalytic cracking, as well as the low pressure storage of natural gas or hydrogen.
LLNL's Saturday lectures explore computational modeling
via computer simulation; fusion modeling; menacing microbes; and simulating the human heart on the world's fastest supercomputer. The lectures are free and will be held in the...
Computational Modelling for the Materials Professional
After completing his PhD in 1988 he joined Carnegie Mellon University, Pittsburgh, and worked closely with the Steel industry, applying computational modelling�...
Computer modeling of piezoelectric transducers
A piezoelectricfinite elementmodeling tool was developed to compute the complete static and dynamic behavior of piezoelectric devices. The exact differential equations governing piezoelectric media are solved numerically. Telephonetransducers
Reinhard Lerch
A Diagnostic Method for Computing the Surface Wind from the Geostrophic Wind Including the Effects of Baroclinity
A diagnostic procedure to compute the surface wind from the geostrophic wind including the effects of baroclinity is designed and tested. Expressions are derived to calculate the similarity functions A and B for use when only the surface ...
Maurice Danard
Key computational modeling issues in Integrated Computational Materials Engineering
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
Property:Data Comparison to Computational Models | Open Energy Information
Comparison to Computational Models Comparison to Computational Models Jump to: navigation, search Property Name Data Comparison to Computational Models Property Type Text Pages using the property "Data Comparison to Computational Models" Showing 14 pages using this property. A Alden Large Flume + Designed as needed Alden Small Flume + Designed as needed Alden Tow Tank + Velocity, flow characteristics Alden Wave Basin + Wave height, period, length, velocity D Davidson Laboratory Tow Tank + Comparisons to validate and improve CFD models are made periodically. M MHL Free Surface Channel + Custom MHL Data Acquisition System includes graphical displays for the results of each sampling channel. MHL Tow Tank + Custom MHL Data Acquisition System includes graphical displays for the results of each sampling channel.
Computational social dynamic modeling of group recruitment.
The Seldon software toolkit combines concepts from agent-based modeling and social science to create a computationally social dynamic model for group recruitment. The underlying recruitment model is based on a unique three-level hybrid agent-based architecture that contains simple agents (level one), abstract agents (level two), and cognitive agents (level three). This uniqueness of this architecture begins with abstract agents that permit the model to include social concepts (gang) or institutional concepts (school) into a typical software simulation environment. The future addition of cognitive agents to the recruitment model will provide a unique entity that does not exist in any agent-based modeling toolkits to date. We use social networks to provide an integrated mesh within and between the different levels. This Java based toolkit is used to analyze different social concepts based on initialization input from the user. The input alters a set of parameters used to influence the values associated with the simple agents, abstract agents, and the interactions (simple agent-simple agent or simple agent-abstract agent) between these entities. The results of phase-1 Seldon toolkit provide insight into how certain social concepts apply to different scenario development for inner city gang recruitment.
Berry, Nina M.; Lee, Marinna; Pickett, Marc; Turnley, Jessica Glicken (Sandia National Laboratories, Albuquerque, NM); Smrcka, Julianne D. (Sandia National Laboratories, Albuquerque, NM); Ko, Teresa H.; Moy, Timothy David (Sandia National Laboratories, Albuquerque, NM); Wu, Benjamin C.
RELAP5-3D Code Includes Athena Features and Models
DOE Green Energy (OSTI)
Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5- 3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
Computing and fabricating multilayer models
We present a method for automatically converting a digital 3D model into a multilayer model: a parallel stack of high-resolution 2D images embedded within a semi-transparent medium. Multilayer models can be produced quickly ...
Holroyd, Michael
Integrating Numerical Computation into the Modeling Instruction Curriculum
We describe a way to introduce physics high school students with no background in programming to computational problem-solving experiences. Our approach builds on the great strides made by the Modeling Instruction reform curriculum. This approach emphasizes the practices of "Developing and using models" and "Computational thinking" highlighted by the NRC K-12 science standards framework. We taught 9th-grade students in a Modeling-Instruction-based physics course to construct computational models using the VPython programming environment. Numerical computation within the Modeling Instruction curriculum provides coherence among the curriculum's different force and motion models, links the various representations which the curriculum employs, and extends the curriculum to include real-world problems that are inaccessible to a purely analytic approach.
Caballero, Marcos D; Aiken, John M; Douglas, Scott S; Scanlon, Erin M; Thoms, Brian; Schatz, Michael F
A Two-Cylinder Model of Cumulus Cells and Its Application in Computing Cumulus Transports
A two-cylinder model suitable for computing vertical transports in cumulus cells is formulated. The model includes explicit computation of perturbation pressure and allows the study of the evolution of raindrop size spectra. Sensitivity tests ...
Man Kong Yau
Refined computational models for laminated shells
This paper presents refined computational models for non homogeneous, deep, doubly curved shells. The theory is based on a kinematical approach in which the continuity conditions for displacements and shear stresses at layer interfaces and on the bounding ... Keywords: bending-torsion warping coupling, multilayered shells, piezoelectric laminates, shear-membrane refinements, stress computations, triangular C1-C1/2 finite element
M. Touratier
Including cognitive biases and distance-based rewards in a connectionist model of complex problem solving
We present a cognitive, connectionist-based model of complex problem solving that integrates cognitive biases and distance-based and environmental rewards under a temporal-difference learning mechanism. The model is tested against experimental data obtained ... Keywords: Cognitive biases, Computational modeling, Distance-reduction heuristic, Problem solving, Reinforcement learning, Temporal-difference learning
Fr�d�ric Dandurand; Thomas R. Shultz; Arnaud Rey
Models and languages for parallel computation
We survey parallel programming models and languages using six criteria to assess their suitability for realistic portable parallel programming. We argue that an ideal model should by easy to program, should have a software development methodology, should ... Keywords: general-purpose parallel computation, logic programming languages, object-oriented languages, parallel programming languages, parallel programming models, software development methods, taxonomy
David B. Skillicorn; Domenico Talia
Modelling energy efficiency for computation
/kg, considered independently from the reduction in flight time. Values taken from the BP Hand- book of Products, 2000. http://www.bp.com/liveassets/bp_internet/aviation/air_bp/STAGING/ local_assets/downloads_pdfs/a/air_bp_products_handbook_04004_1.pdf 20 2... per unit computation might be reduced by a factor of 1011 [Koomey et al., 2011]. Improvements since then amount to around 105, and if Koomey�s Law continues, such a limit would be reached sometime in the year 2041. More fundamentally still, Landauer...
Reams, Charles
Integrated Computational Modeling of Welding � Development to ...
Integrated computational modeling is considered as a viable pathway to ... lack of a standard verification and validation (V&V) documents to build a technical case. ... Evolution with the Impact of Anisotropic Grain Boundary Energy and Mobility.
Modeling-Computer Simulations | Open Energy Information
Modeling-Computer Simulations Modeling-Computer Simulations Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Modeling-Computer Simulations Details Activities (78) Areas (31) Regions (5) NEPA(0) Exploration Technique Information Exploration Group: Data and Modeling Techniques Exploration Sub Group: Modeling Techniques Parent Exploration Technique: Modeling Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Stress fields and magnitudes Hydrological: Visualization and prediction of the flow patterns and characteristics of geothermal fluids Thermal: Thermal conduction and convection patterns in the subsurface Cost Information Low-End Estimate (USD): 85.008,500 centUSD 0.085 kUSD 8.5e-5 MUSD 8.5e-8 TUSD / hour Median Estimate (USD): 195.0019,500 centUSD
Parallel Computing for Terrestrial Ecosystem Carbon Modeling
Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO{sub 2}. The influence of terrestrial ecosystems on atmospheric CO{sub 2} can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO{sub 2} concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO{sub 2} uptake and respiratory CO{sub 2} release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change impact analysis.
Wang, Dali [ORNL; Post, Wilfred M [ORNL; Ricciuto, Daniel M [ORNL; Berry, Michael [University of Tennessee, Knoxville (UTK)
Computational Modeling and Simulation of Advanced Materials for ...
Symposium, Computational Modeling and Simulation of Advanced Materials for Energy Applications. Sponsorship, TMS/ASM: Computational Materials Science�...
Modeling of Geothermal Reservoirs: Fundamental Processes, Computer
Page Page Edit with form History Facebook icon Twitter icon » Modeling of Geothermal Reservoirs: Fundamental Processes, Computer Simulation and Field Applications Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Modeling of Geothermal Reservoirs: Fundamental Processes, Computer Simulation and Field Applications Abstract This article attempts to critically evaluate the present state of the art of geothermal reservoir simulation. Methodological aspects of geothermal reservoir modeling are briefly reviewed, with special emphasis on flow in fractured media. We then examine some applications of numerical simulation to studies of reservoir dynamics, well test design and analysis, and modeling of specific fields. Tangible impacts of reservoir simulation
Expanded rock blast modeling capabilities of DMC{_}BLAST, including buffer blasting
A discrete element computer program named DMC{_}BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in 2-D. DMC{_}BLAST calculations compare favorably with data from actual bench blasts. The blast modeling capabilities of DMC{_}BLAST have been expanded to include independently dipping geologic layers, top surface, bottom surface and pit floor. The pit can also now be defined using coordinates based on the toe of the bench. A method for modeling decked explosives has been developed which allows accurate treatment of the inert materials (stemming) in the explosive column and approximate treatment of different explosives in the same blasthole. A DMC{_}BLAST user can specify decking through a specific geologic layer with either inert material or a different explosive. Another new feature of DMC{_}BLAST is specification of an uplift angle which is the angle between the normal to the blasthole and a vector defining the direction of explosive loading on particles adjacent to the blasthole. A buffer (choke) blast capability has been added for situations where previously blasted material is adjacent to the free face of the bench preventing any significant lateral motion during the blast.
Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States); Tidman, J.P.; Chung, S.H. [ICI Explosives (Canada)
A Generalized Streaming Model for Concurrent Computing
Multicore parallel programming has some very difficult problems such as deadlocks during synchronizations and race conditions brought by concurrency. Added to the difficulty is the lack of a simple, well-accepted computing model for multicore architectures--because of that it is hard to develop powerful programming environments and debugging tools. To tackle the challenges, we promote a generalized stream computing model, inspired by previous researches on stream computing, that unifies parallelization strategies for programming language design, compiler design and operating system design. Our model provides a high-level abstraction in designing language constructs to convey concepts of concurrent operations, in organizing a program's runtime layout for parallel execution, and in scheduling concurrent instruction blocks through runtime and/or operating systems. In this paper, we give a high-level description of the proposed model: we define the foundation of the model, show its simplicity through algebraic/co...
Wang, Yibing
Mathematical Models of Computer Security
In this chapter I present a process algebraic approach to the modelling of security properties and policies. I will concentrate on the concept of secrecy, also known as confidentiality, and in particular on the notion of non-interference. Non-interference ...
Peter Y. A. Ryan
The Uflow Computational Model and Intermediate Format
This report motivates and defines a general-purpose, architecture independent, parallel computational model, which captures the intuitions which underlie the design of the United Functions and Objects programming language. The model has two aspects, which turn out to be a traditional dataflow model and an actor-like model, with a very simple interface between the two. Certain aspects of the model, particularly strictness, maximum parallelism, and lack of suspension are stressed. The implications of introducing stateful objects are carefully spelled out. The model has several purposes, although we largely describe it as it would be used for visualising the execution of programs. The model is embodied in a textual intermediate format, and in a set of UFO data structures. This report also serves as a definition of the intermediate format, and gives a brief overview of the data structures. 1 Introduction This report serves two purposes. Firstly, in sections 1 to 9, the Uflow computational...
John Sargeant; Chris Kirkham; Steve Anderson
February » February » Simple computer models unravel genetic stress reactions in cells Simple computer models unravel genetic stress reactions in cells Integrated biological and computational methods provide insight into why genes are activated. February 8, 2013 When complete, these barriers will be a portion of the NMSSUP upgrade. This molecular structure depicts a yeast transfer ribonucleic acid (tRNA), which carries a single amino acid to the ribosome during protein construction. A combined experimental and computational approach, to better understand signaling pathways that lead to genetic mutations, is at the core of this research. Contact thumbnail of Brian Munsky, PhD Distinguished Postdoctoral Fellow Brian Munsky, PhD Information Services, Advanced Measurement Science
Modeling-Computer Simulations (Walker, Et Al., 2005) | Open Energy...
Modeling-Computer Simulations (Walker, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations (Walker, Et...
Modeling-Computer Simulations At White Mountains Area (Goff ...
Modeling-Computer Simulations At White Mountains Area (Goff & Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer...
Modeling-Computer Simulations At Nw Basin & Range Region (Biasi...
Modeling-Computer Simulations At Nw Basin & Range Region (Biasi, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer...
Molecular Dynamics Model of Ultraviolet Matrix-Assisted Laser Desorption/Ionization Including Ionization Processes
Molecular Dynamics Model of Ultraviolet Matrix-Assisted Laser Desorption/Ionization Including A molecular dynamics model of UV-MALDI including ionization processes is presented. In addition/desorption of molecular systems, it includes radiative and nonradiative decay, exciton hopping, two pooling processes
Zhigilei, Leonid V.
Causal sets from simple models of computation
Causality among events is widely recognized as a most fundamental structure of spacetime, and causal sets have been proposed as discrete models of the latter in the context of quantum gravity theories, notably in the Causal Set Programme. In the rather different context of what might be called the 'Computational Universe Programme' -- one which associates the complexity of physical phenomena to the emergent features of models such as cellular automata -- a choice problem arises with respect to the variety of formal systems that, in virtue of their computational universality (Turing-completeness), qualify as equally good candidates for a computational, unified theory of physics. This paper proposes Causal Sets as the only objects of physical significance and relevance to be considered under the 'computational universe' perspective, and as the appropriate abstraction for shielding the unessential details of the many different computationally universal candidate models. At the same time, we propose a fully deterministic, radical alternative to the probabilistic techniques currently considered in the Causal Set Programme for growing discrete spacetimes. We investigate a number of computation models by grouping them into two broad classes, based on the support on which they operate; in one case this is linear, like a tape or a string of symbols; in the other, it is a two-dimensional grid or a planar graph. For each model we identify the causality relation among computation events, implement it, and conduct a possibly exhaustive exploration of the associated causal set space, while examining quantitative and qualitative features such as dimensionality, curvature, planarity, emergence of pseudo-randomness, causal set substructures and particles.
Tommaso Bolognesi
On a Three Step Model of Anaerobic Digestion Including the Hydrolysis of
On a Three Step Model of Anaerobic Digestion Including the Hydrolysis of Particulate Matter R degradation, chemostat, models, growth rate, equilibrium, bistability. 1. INTRODUCTION Anaerobic digestion, the anaerobic digestion is generally considered as a three step process: hydrolysis and liquefaction
Paris-Sud XI, Université de
Including Surface Kinetic Effects in Simple Models of Ice Vapor Diffusion
A model for kinetically-limited vapor growth and aspect ratio evolution of atmospheric single ice crystals is presented. The method is based on the adaptive habit model of Chen and Lamb (1994), but is modified to include the deposition ...
Chengzhu Zhang; Jerry Y. Harrington
A Simple Model of Abyssal Circulation, Including Effects of Wind, Buoyancy and Topography
We examine problems of steady abyssal circulation using an inviscid planetary geostrophic layered model. The model includes an active wind-driven upper layer and arbitrary topography; forcing is in the form of specified interlayer mass fluxes ...
Susan L. Hautala; Stephen C. Riser
Computational Modeling of Uranium Hydriding and Complexes
Uranium hydriding is one of the most important processes that has received considerable attention over many years. Although many experimental and modeling studies have been carried out concerning thermochemistry, diffusion kinetics and mechanisms of U-hydriding, very little is known about the electronic structure and electronic features that govern the U-hydriding process. Yet it is the electronic feature that controls the activation barrier and thus the rate of hydriding. Moreover the role of impurities and the role of the product UH{sub 3} on hydriding rating are not fully understood. An early study by Condon and Larson concerns with the kinetics of U-hydrogen system and a mathematical model for the U-hydriding process. They proposed that diffusion in the reactant phase by hydrogen before nucleation to form hydride phase and that the reaction is first order for hydriding and zero order for dehydriding. Condon has also calculated and measures the reaction rates of U-hydriding and proposed a diffusion model for the U-hydriding. This model was found to be in excellent agreement with the experimental reaction rates. From the slopes of the Arrhenius plot the activation energy was calculated as 6.35 kcal/mole. In a subsequent study Kirkpatrick formulated a close-form for approximate solution to Condon's equation. Bloch and Mintz have proposed the kinetics and mechanism for the U-H reaction over a wide range of pressures and temperatures. They have discussed their results through two models, one, which considers hydrogen diffusion through a protective UH{sub 3} product layer, and the second where hydride growth occurs at the hydride-metal interface. These authors obtained two-dimensional fits of experimental data to the pressure-temperature reactions. Kirkpatrick and Condon have obtained a linear solution to hydriding of uranium. These authors showed that the calculated reaction rates compared quite well with the experimental data at a hydrogen pressure of 1 atm. Powell et al. have studied U-hydriding in ultrahigh vacuum and obtained the linear rate data over a wide range of temperatures and pressures. They found reversible hydrogen sorption on the UH{sub 3} reaction product from kinetic effects at 21 C. This demonstrates restarting of the hydriding process in the presence of UH{sub 3} reaction product. DeMint and Leckey have shown that Si impurities dramatically accelerate the U-hydriding rates. We report our recent results of relativistic computations that vary from complete active space multi-configuration interaction (CAS-MCSCF) followed by multi-reference configuration interaction (MRSDCI) computations that included up to 50 million configurations for modeling of uranium-hydriding with cluster models will be presented.
Balasubramanian, K; Siekhaus, W J; McLean, W
Modeling Computations in a Semantic Network
Semantic network research has seen a resurgence from its early history in the cognitive sciences with the inception of the Semantic Web initiative. The Semantic Web effort has brought forth an array of technologies that support the encoding, storage, and querying of the semantic network data structure at the world stage. Currently, the popular conception of the Semantic Web is that of a data modeling medium where real and conceptual entities are related in semantically meaningful ways. However, new models have emerged that explicitly encode procedural information within the semantic network substrate. With these new technologies, the Semantic Web has evolved from a data modeling medium to a computational medium. This article provides a classification of existing computational modeling efforts and the requirements of supporting technologies that will aid in the further growth of this burgeoning domain.
Marko A. Rodriguez; Johan Bollen
Computer Models of Vocal Tract Evolution: An Overview and Critique
Human speech has been investigated with computer models since the invention of digital computers, and models of the evolution of speech first appeared in the late 1960s and early 1970s. Speech science and computer models have a long shared history because ... Keywords: computer modeling, descended larynx, evolution of speech, vocal tract evolution
Bart De Boer; W. Tecumseh Fitch
Cloud computing and electricity: beyond the utility model
Assessing the strengths, weaknesses, and general applicability of the computing-as-utility business model.
Erik Brynjolfsson; Paul Hofmann; John Jordan
Computer Aided Design Modeling for Heterogeneous Objects
Heterogeneous object design is an active research area in recent years. The conventional CAD modeling approaches only provide geometry and topology of the object, but do not contain any information with regard to the materials of the object and so can not be used for the fabrication of heterogeneous objects (HO) through rapid prototyping. Current research focuses on computer-aided design issues in heterogeneous object design. A new CAD modeling approach is proposed to integrate the material information into geometric regions thus model the material distributions in the heterogeneous object. The gradient references are used to represent the complex geometry heterogeneous objects which have simultaneous geometry intricacies and accurate material distributions. The gradient references helps in flexible manipulability and control to heterogeneous objects, which guarantees the local control over gradient regions of developed heterogeneous objects. A systematic approach on data flow, processing, computer visualizat...
Gupta, Vikas; Tandon, Puneet
Earthquake ground motion modeling on parallel computers
We describe the design and discuss the performance of a parallel elastic wave propagation simulator that is being used to model and study earthquake-induced ground motion in large sedimentary basins. The components of the system include mesh generators, ...
Hesheng Bao; Jacobo Bielak; Omar Ghattas; Loukas F. Kallivokas; David R. O'Hallaron; Jonathan R. Shewchuk; Jifeng Xu
Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.
Ibrahim, Essam A
Modeling-Computer Simulations At Valles Caldera - Sulphur Springs Area
Roberts, Et Al., 1995) Roberts, Et Al., 1995) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Valles Caldera - Sulphur Springs Area (Roberts, Et Al., 1995) Exploration Activity Details Location Valles Caldera - Sulphur Springs Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Modeling of the amplitude data, using the Aki-Lamer method, confirmed that this anomaly exists and we estimated quantitative parameters defining it. All model parameters were physically meaningful except for one. The value for Q inside the anomaly, required to explain the data, was unrealistically low. This was probably due to the inability to include additional structural complexity within the low-Q zone that would account for a
Interlanguages and synchronic models of computation
A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...
Berka, Alexander Victor
A Soft Computing Model for Physicians' Decision Process
In this paper the author presents a kind of Soft Computing Technique, mainly an application of fuzzy set theory of Prof. Zadeh [16], on a problem of Medical Experts Systems. The choosen problem is on design of a physician's decision model which can take crisp as well as fuzzy data as input, unlike the traditional models. The author presents a mathematical model based on fuzzy set theory for physician aided evaluation of a complete representation of information emanating from the initial interview including patient past history, present symptoms, and signs observed upon physical examination and results of clinical and diagnostic tests.
Biswas, Siddharths Sankar
Empirical Validation of a Transient Computer Model for ...
Page 1. _� EMPIRICAL VALIDATION OF A lRANSIENT COMPUTER MODEL FOR COMBINED HEAT AND MOISTURE TRANSFER ...
Modeling-Computer Simulations At Central Nevada Seismic Zone...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Central Nevada Seismic Zone Region (Pritchett, 2004) Exploration...
Modeling-Computer Simulations At Dixie Valley Geothermal Field...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Dixie Valley Geothermal Field Area (Wisian & Blackwell, 2004)...
Modeling-Computer Simulations At Desert Peak Area (Wisian & Blackwell...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Desert Peak Area (Wisian & Blackwell, 2004) Exploration Activity...
Computable General Equilibrium Models for Sustainability Impact Assessment:
Computable General Equilibrium Models for Sustainability Impact Assessment: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Agency/Company /Organization: DG Joint Research Centre, European Commission, University of Heidelberg Topics: Co-benefits assessment Resource Type: Guide/manual, Publications, Software/modeling tools User Interface: Other Website: iatools.jrc.ec.europa.eu/docs/ecol_econ_2006.pdf Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Screenshot References: Computable general equilibrium models[1] Abstract "Sustainability Impact Assessment (SIA) of economic, environmental, and
Computational models of intergroup competition and warfare.
This document reports on the research of Kenneth Letendre, the recipient of a Sandia Graduate Research Fellowship at the University of New Mexico. Warfare is an extreme form of intergroup competition in which individuals make extreme sacrifices for the benefit of their nation or other group to which they belong. Among animals, limited, non-lethal competition is the norm. It is not fully understood what factors lead to warfare. We studied the global variation in the frequency of civil conflict among countries of the world, and its positive association with variation in the intensity of infectious disease. We demonstrated that the burden of human infectious disease importantly predicts the frequency of civil conflict and tested a causal model for this association based on the parasite-stress theory of sociality. We also investigated the organization of social foraging by colonies of harvester ants in the genus Pogonomyrmex, using both field studies and computer models.
Letendre, Kenneth (University of New Mexico); Abbott, Robert G.
To study the effects of interstellar pickup protons and turbulence on the structure and dynamics of the solar wind, we have developed a fully three-dimensional magnetohydrodynamic solar wind model that treats interstellar pickup protons as a separate fluid and incorporates the transport of turbulence and turbulent heating. The governing system of equations combines the mean-field equations for the solar wind plasma, magnetic field, and pickup protons and the turbulence transport equations for the turbulent energy, normalized cross-helicity, and correlation length. The model equations account for photoionization of interstellar hydrogen atoms and their charge exchange with solar wind protons, energy transfer from pickup protons to solar wind protons, and plasma heating by turbulent dissipation. Separate mass and energy equations are used for the solar wind and pickup protons, though a single momentum equation is employed under the assumption that the pickup protons are comoving with the solar wind protons. We compute the global structure of the solar wind plasma, magnetic field, and turbulence in the region from 0.3 to 100 AU for a source magnetic dipole on the Sun tilted by 0 Degree-Sign -90 Degree-Sign and compare our results with Voyager 2 observations. The results computed with and without pickup protons are superposed to evaluate quantitatively the deceleration and heating effects of pickup protons, the overall compression of the magnetic field in the outer heliosphere caused by deceleration, and the weakening of corotating interaction regions by the thermal pressure of pickup protons.
Usmanov, Arcadi V.; Matthaeus, William H. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Goldstein, Melvyn L., E-mail: email@example.com [Code 673, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
QUALITATIVE PROPERTIES OF A 3-STEPS MODEL OF ANAEROBIC DIGESTION INCLUDING HYDROLYSIS-SupAgro MISTEA, 2 p. Viala 34060 Montpellier, France, firstname.lastname@example.com Introduction. Anaerobic digestion, the anaerobic digestion is generally considered as a three step process: hydrolysis and liquefaction
MMA, A Computer Code for Multi-Model Analysis
This report documents the Multi-Model Analysis (MMA) computer code. MMA can be used to evaluate results from alternative models of a single system using the same set of observations for all models. As long as the observations, the observation weighting, and system being represented are the same, the models can differ in nearly any way imaginable. For example, they may include different processes, different simulation software, different temporal definitions (for example, steady-state and transient models could be considered), and so on. The multiple models need to be calibrated by nonlinear regression. Calibration of the individual models needs to be completed before application of MMA. MMA can be used to rank models and calculate posterior model probabilities. These can be used to (1) determine the relative importance of the characteristics embodied in the alternative models, (2) calculate model-averaged parameter estimates and predictions, and (3) quantify the uncertainty of parameter estimates and predictions in a way that integrates the variations represented by the alternative models. There is a lack of consensus on what model analysis methods are best, so MMA provides four default methods. Two are based on Kullback-Leibler information, and use the AIC (Akaike Information Criterion) or AICc (second-order-bias-corrected AIC) model discrimination criteria. The other two default methods are the BIC (Bayesian Information Criterion) and the KIC (Kashyap Information Criterion) model discrimination criteria. Use of the KIC criterion is equivalent to using the maximum-likelihood Bayesian model averaging (MLBMA) method. AIC, AICc, and BIC can be derived from Frequentist or Bayesian arguments. The default methods based on Kullback-Leibler information have a number of theoretical advantages, including that they tend to favor more complicated models as more data become available than do the other methods, which makes sense in many situations.
Eileen P. Poeter and Mary C. Hill
QCD Equation of State From a Chiral Hadronic Model Including Quark Degrees of Freedom
This work presents an effective model for strongly interacting matter and the QCD equation of state (EoS). The model includes both hadron and quark degrees of freedom and takes into account the transition of chiral symmetry restoration as well as the deconfinement phase transition. At low temperatures $T$ and baryonic densities $\\rho_B$ a hadron resonance gas is described using a SU(3)-flavor sigma-omega model and a quark phase is introduced in analogy to PNJL models for higher $T$ and $\\rho_B$. In this way, the correct asymptotic degrees of freedom are used in a wide range of $T$ and $\\rho_B$. Here, results of this model concerning the chiral and deconfinement phase transitions and thermodynamic model properties are presented. Large hadron resonance multiplicities in the transition region emphasize the importance of heavy-mass resonance states in this region and their impact on the chiral transition behavior. The resulting phase diagram of QCD matter at small chemical potentials is in line with latest lattice QCD and thermal model results.
Philip Rau; Jan Steinheimer; Stefan Schramm; Horst St�cker
Unsolicited Projects in 2012: Research in Computer Architecture, Modeling,
Office of Science (SC) Website
2: Research in Computer Architecture, 2: Research in Computer Architecture, Modeling, and Evolving MPI for Exascale Advanced Scientific Computing Research (ASCR) ASCR Home About Research Applied Mathematics Computer Science Exascale Tools Workshop Programming Challenges Workshop Architectures I Workshop External link Architectures II Workshop External link Next Generation Networking Scientific Discovery through Advanced Computing (SciDAC) Computational Science Graduate Fellowship (CSGF) ASCR SBIR-STTR Facilities Science Highlights Benefits of ASCR Funding Opportunities Advanced Scientific Computing Advisory Committee (ASCAC) News & Resources Contact Information Advanced Scientific Computing Research U.S. Department of Energy SC-21/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-7486 F: (301)
Comments on �A Diagnostic Method for Computing the Surface Wind from the Geostrophic Wind Including the Effects of Baroclinity�
A numerical method for solving the generalized Ekman problem in which both geostrophic wind and eddy diffusivity are allowed to vary with height is used to compute surface cross-isobaric flow angles and surface winds. These are compared with ...
Lynn L. LeBlanc; Eric A. Pani
Periodic surface modeling for computer aided nano design
Current solid and surface modeling methods based on Euclidean geometry in traditional computer aided design are not efficient in constructing a large number of atoms and particles. In this paper, we propose a periodic surface model for computer aided ... Keywords: Computer aided nano design, Hyperbolic geometry, Minimal surface, Periodic surface
Yan Wang
Climate Change Modeling:Computational Opportunities and Challenges
High- delity climate models are the workhorses of modern climate change sciences. In this article, the authors focus on several computational issues associated with climate change modeling, covering simulation methodologies, temporal and spatial modeling restrictions, the role of high-end computing, as well as the importance of data-driven regional climate impact modeling.
Wang, Dali [ORNL; Post, Wilfred M [ORNL; Wilson, Bruce E [ORNL
Engineering computation under uncertainty - Capabilities of non-traditional models
This paper provides a review of various non-traditional uncertainty models for engineering computation and responds to the criticism of those models. This criticism imputes inappropriateness in representing uncertain quantities and an absence of numerically ... Keywords: Computational efficiency, Fuzzy models, Fuzzy randomness, Imprecise probabilities, Interval analysis, Uncertainty modeling
Bernd M�ller; Michael Beer
The Food Crises: A quantitative model of food prices including speculators and ethanol conversion
Recent increases in basic food prices are severely impacting vulnerable populations worldwide. Proposed causes such as shortages of grain due to adverse weather, increasing meat consumption in China and India, conversion of corn to ethanol in the US, and investor speculation on commodity markets lead to widely differing implications for policy. A lack of clarity about which factors are responsible reinforces policy inaction. Here, for the first time, we construct a dynamic model that quantitatively agrees with food prices. The results show that the dominant causes of price increases are investor speculation and ethanol conversion. Models that just treat supply and demand are not consistent with the actual price dynamics. The two sharp peaks in 2007/2008 and 2010/2011 are specifically due to investor speculation, while an underlying upward trend is due to increasing demand from ethanol conversion. The model includes investor trend following as well as shifting between commodities, equities and bonds to take ad...
Lagi, Marco; Bertrand, Karla Z; Bar-Yam, Yaneer
Application of computer blast modeling to oil shale mining
In recent years there has been considerable interest in the development of computer models to describe rock fragmentation by blasting. The interest for this work has come primarily for application to large scale coal or mineral surface mines. However, the basic models developed for these applications are equally applicable for examining typical underground oil shale operations. Models that can predict blasting results starting from first principles can impact room and pillar mining in a number of ways including optimizing round design, control of particle size, evaluation of new explosives, minimizing pillar damage, and developing blasting schemes that can be used in conjunction with continuous miners. In this study, the authors explore how these codes can be used to model the blasting geometry encountered in room and pillar mining operations.
Hommert, P.J.; Preece, D.S.; Thorne, B.J. (Sandia National Labs., Albuquerque, NM (USA))
Modeling the fracture of ice sheets on parallel computers.
The objective of this project is to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. Dramatic illustrations of fracture-induced phenomena most notably include the recent collapse of ice shelves in Antarctica (e.g. partial collapse of the Wilkins shelf in March of 2008 and the diminishing extent of the Larsen B shelf from 1998 to 2002). Other fracture examples include ice calving (fracture of icebergs) which is presently approximated in simplistic ways within ice sheet models, and the draining of supraglacial lakes through a complex network of cracks, a so called ice sheet plumbing system, that is believed to cause accelerated ice sheet flows due essentially to lubrication of the contact surface with the ground. These dramatic changes are emblematic of the ongoing change in the Earth's polar regions and highlight the important role of fracturing ice. To model ice fracture, a simulation capability will be designed centered around extended finite elements and solved by specialized multigrid methods on parallel computers. In addition, appropriate dynamic load balancing techniques will be employed to ensure an approximate equal amount of work for each processor.
Waisman, Haim (Columbia University); Bell, Robin (Columbia University); Keyes, David (Columbia University); Boman, Erik Gunnar; Tuminaro, Raymond Stephen
Camera Models and Fundamental Concepts Used in Geometric Computer Vision
This survey is mainly motivated by the increased availability and use of panoramic image acquisition devices, in computer vision and various of its applications. Different technologies and different computational models thereof exist and algorithms and ...
Peter Sturm; Srikumar Ramalingam; Jean-Philippe Tardif; Simone Gasparini; Jo�o Barreto
Integration of engineering models in computer-aided preliminary design
The problems of the integration of engineering models in computer-aided preliminary design are reviewed. This paper details the research, development, and testing of modifications to Paper Airplane, a LISP-based computer ...
Lajoie, Ronnie M.
LANL computer model boosts engine efficiency
Environment Feature Stories Public Reading Room: Environmental Documents, Reports LANL Home Phonebook Calendar Video Newsroom News Stories September LANL computer...
The development of facilities to deal with the disposition of nuclear materials at an acceptable level of Occupational Radiation Exposure (ORE) is a significant issue facing the nuclear community. One solution is to minimize the worker's exposure though the use of automated systems. However, the adoption of automated systems for these tasks is hampered by the challenging requirements that these systems must meet in order to be cost effective solutions in the hazardous nuclear materials processing environment. Retrofitting current glove box technologies with automation systems represents potential near-term technology that can be applied to reduce worker ORE associated with work in nuclear materials processing facilities. Successful deployment of automation systems for these applications requires the development of testing and deployment strategies to ensure the highest level of safety and effectiveness. Historically, safety tests are conducted with glove box mock-ups around the finished design. This late detection of problems leads to expensive redesigns and costly deployment delays. With wide spread availability of computers and cost effective simulation software it is possible to discover and fix problems early in the design stages. Computer simulators can easily create a complete model of the system allowing a safe medium for testing potential failures and design shortcomings. The majority of design specification is now done on computer and moving that information to a model is relatively straightforward. With a complete model and results from a Failure Mode Effect Analysis (FMEA), redesigns can be worked early. Additional issues such as user accessibility, component replacement, and alignment problems can be tackled early in the virtual environment provided by computer simulation. In this case, a commercial simulation package is used to simulate a lathe process operation at the Los Alamos National Laboratory (LANL). The Lathe process operation is indicative of most glove box operations and demonstrates the ability and advantages of advance computer based modeling. The three-dimensional model also enables better comprehension of problems to non-technical staff. There are many barriers to the seamless integration between the initial design specifications and a computer simulation. Problems include the lack of a standard model and inexact manufacturing of components used in the glove box. The benefits and drawbacks are discussed; however, the results are useful.
Enhanced absorption cycle computer model. Final report
Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperatures boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorptions systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system`s components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H{sub 2}O triple-effect cycles, LiCl-H{sub 2}O solar-powered open absorption cycles, and NH{sub 3}-H{sub 2}O single-effect and generator-absorber heat exchange cycles. An appendix contains the User`s Manual.
Grossman, G.; Wilk, M. [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering
Hydrogen program combustion research: Three dimensional computational modeling
We have significantly increased our computational modeling capability by the addition of a vertical valve model in KIVA-3, code used internationally for engine design. In this report the implementation and application of the valve model is described. The model is shown to reproduce the experimentally verified intake flow problem examined by Hessel. Furthermore, the sensitivity and performance of the model is examined for the geometry and conditions of the hydrogen-fueled Onan engine in development at Sandia National Laboratory. Overall the valve model is shown to have comparable accuracy as the general flow simulation capability in KIVA-3, which has been well validated by past comparisons to experiments. In the exploratory simulations of the Onan engine, the standard use of the single kinetic reaction for hydrogen oxidation was found to be inadequate for modeling the hydrogen combustion because of its inability to describe both the observed laminar flame speed and the absence of autoignition in the Onan engine. We propose a temporary solution that inhibits the autoignition without sacrificing the ability to model spark ignition. In the absence of experimental data on the Onan engine, a computational investigation was undertaken to evaluate the importance of modeling the intake flow on the combustion and NO{sub x} emissions. A simulation that began with the compression of a quiescent hydrogen-air mixture was compared to a simulation of the full induction process with resolved opening and closing of the intake valve. Although minor differences were observed in the cylinder-averaged pressure, temperature, bulk-flow kinetic energy and turbulent kinetic energy, large differences where observed in the hydrogen combustion rate and NO{sub x} emissions. The flow state at combustion is highly heterogeneous and sensitive to the details of the bulk and turbulent flow and that an accurate simulation of the Onan engine must include the modeling of the air-fuel induction.
Johnson, N.L.; Amsden, A.A.; Butler, T.D.
In the current fiscal year FY01, several CFD simulations were conducted to investigate the effects of moisture in biomass/coal, particle injection locations, and flow parameters on carbon burnout and NO{sub x} inside a 150 MW GEEZER industrial boiler. Various simulations were designed to predict the suitability of biomass cofiring in coal combustors, and to explore the possibility of using biomass as a reburning fuel to reduce NO{sub x}. Some additional CFD simulations were also conducted on CERF combustor to examine the combustion characteristics of pulverized coal in enriched O{sub 2}/CO{sub 2} environments. Most of the CFD models available in the literature treat particles to be point masses with uniform temperature inside the particles. This isothermal condition may not be suitable for larger biomass particles. To this end, a stand alone program was developed from the first principles to account for heat conduction from the surface of the particle to its center. It is envisaged that the recently developed non-isothermal stand alone module will be integrated with the Fluent solver during next fiscal year to accurately predict the carbon burnout from larger biomass particles. Anisotropy in heat transfer in radial and axial will be explored using different conductivities in radial and axial directions. The above models will be validated/tested on various fullscale industrial boilers. The current NO{sub x} modules will be modified to account for local CH, CH{sub 2}, and CH{sub 3} radicals chemistry, currently it is based on global chemistry. It may also be worth exploring the effect of enriched O{sub 2}/CO{sub 2} environment on carbon burnout and NO{sub x} concentration. The research objective of this study is to develop a 3-Dimensional Combustor Model for Biomass Co-firing and reburning applications using the Fluent Computational Fluid Dynamics Code.
Mathur, M.P.; Freeman, Mark (U.S. DOE National Energy Technology Laboratory); Gera, Dinesh (Fluent, Inc.)
Extended three-dimensional ADCIRC hydrodynamic model to include baroclinic flow and sediment transport
The objective of this research is to identify the circulation patterns of the water and sediment fluxes in coastal and estuarine zones, where the shoaling processes correlate with tide generating flow patterns. The research provides a better understanding of the characteristics of spatial and temporal variability of currents. An important deviation from previous research is the inclusion of the baroclinic term, which becomes very important in density driven flows. The understanding of this process provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model is used to calculate the water circulation. The model is based on the three-dimensional (3D) version of Advanced Circulation (AD-CIRC) Hydrodynamic Model with extending the Sediment Transport module. The model is based on the finite element method on unstructured grids. The output of the hydrody-namic model is used to estimate spatial and temporal advections, dispersions and bottom shear stress for the erosion, suspension, deposition and transport of sediment. The model development includes extending the existing three-dimensional (3D) ADCIRC Model with (1) baroclinic forcing term and (2) transport module of suspended and soluble materials. The transport module covers the erosion, material suspension and deposition processes for both cohesive and non-cohesive type sediments. The inclusion of the baroclinic demonstrates the potential of over or underpredicting the total net transport of suspended cohesive sediment under influence of currents. The model provides less than 6% error of theoretical mass conservation for eroded, suspended and deposited sediment material. The inclusion of the baroclinic term in stratified water demonstrates the prevailing longshore sediment transport. It is shown that the model has an application to the transport of the cohesive sediments from the mouth of the Mississippi River along the north shore of the Gulf of Mexico towards and along the Texas coast. The model is also applicable to determine the design erosion thickness of a cap for isolating contaminated dredged material and to evaluate the appro-priate grain size of cap sediments to minimize the erosion.
Pandoe, Wahyu Widodo
Department of Computing CSP||B modelling for railway verification
University of Surrey Department of Computing Computing Sciences Report CS-12-03 CSP||B modelling Schneider Helen Treharne March 30th 2012 #12;CSP||B modelling for railway verification: the double junction work in verifying railway systems through CSP k B modelling and analysis. In particular we consider
Doran, Simon J.
Global sensitivity analysis of stochastic computer models with joint metamodels
The global sensitivity analysis method used to quantify the influence of uncertain input variables on the variability in numerical model responses has already been applied to deterministic computer codes; deterministic means here that the same set of ... Keywords: Computer experiment, Gaussian process, Generalized additive model, Joint modeling, Sobol indices, Uncertainty
Amandine Marrel; Bertrand Iooss; S�bastien Veiga; Mathieu Ribatet
Computer modeling of jet mixing in INEL waste tanks
The objective of this study is to examine the feasibility of using submerged jet mixing pumps to mobilize and suspend settled sludge materials in INEL High Level Radioactive Waste Tanks. Scenarios include removing the heel (a shallow liquid and sludge layer remaining after tank emptying processes) and mobilizing and suspending solids in full or partially full tanks. The approach used was to (1) briefly review jet mixing theory, (2) review erosion literature in order to identify and estimate important sludge characterization parameters (3) perform computer modeling of submerged liquid mixing jets in INEL tank geometries, (4) develop analytical models from which pump operating conditions and mixing times can be estimated, and (5) analyze model results to determine overall feasibility of using jet mixing pumps and make design recommendations.
Meyer, P.A.
Modeling-Computer Simulations At Nevada Test And Training Range...
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NEAMS ToolKit: advanced computational tools for modeling & simulation...
NEAMS ToolKit: advanced computational tools for modeling & simulation of advanced reactor systems Director's Welcome Organization Achievements Highlights Fact Sheets, Brochures &...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Central Nevada Seismic Zone Region (Biasi, Et Al., 2009) Exploration...
Modeling-Computer Simulations At Walker-Lane Transitional Zone...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Walker-Lane Transitional Zone Region (Biasi, Et Al., 2009) Exploration...
Modeling-Computer Simulations At Northern Basin & Range Region...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Northern Basin & Range Region (Blackwell, Et Al., 2003) Exploration...
Modeling-Computer Simulations At Nw Basin & Range Region (Pritchett...
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navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Walker-Lane Transitional Zone Region (Pritchett, 2004) Exploration...
Modeling-Computer Simulations At Valles Caldera - Sulphur Springs...
Modeling-Computer Simulations At Valles Caldera - Sulphur Springs Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...
Modeling-Computer Simulations At Long Valley Caldera Area (Farrar...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Long Valley Caldera Area (Farrar, Et Al., 2003) Exploration Activity...
Modeling-Computer Simulations At San Juan Volcanic Field Area...
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Modeling-Computer Simulations At Fish Lake Valley Area (Deymonaz...
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Modeling-Computer Simulations At Long Valley Caldera Area (Pribnow...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Long Valley Caldera Area (Pribnow, Et Al., 2003) Exploration Activity...
Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Goff & Decker, 1983) Exploration...
Modeling-Computer Simulations At Valles Caldera - Redondo Area...
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Modeling-Computer Simulations At Valles Caldera - Sulphur Springs Area (Roberts, Et Al., 1995) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...
Modeling-Computer Simulations At Chocolate Mountains Area (Alm...
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Modeling-Computer Simulations At Long Valley Caldera Area (Newman...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Long Valley Caldera Area (Newman, Et Al., 2006) Exploration Activity...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Heiken & Goff, 1983) Exploration...
Modeling-Computer Simulations At Central Nevada Seismic Zone Region (Blackwell, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...
Scientists use world's fastest computer to model materials under...
Materials under extreme conditions Scientists use world's fastest computer to model materials under extreme conditions Materials scientists are for the first time attempting to...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Dixie Valley Geothermal Field Area (Blackwell, Et Al., 2009)...
Modeling-Computer Simulations At Stillwater Area (Wisian & Blackwell...
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Modeling-Computer Simulations At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...
Modeling-Computer Simulations At The Needles Area (Bell & Ramelli...
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Modeling-Computer Simulations At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...
Utilization of Computer Modeling in Superalloy Forging ... - TMS
Computer simulation of superalloy metal forming is now an integral part of forging design. Process modeling is being used for tasks such as definition of preform�...
Modeling-Computer Simulations At Kilauea East Rift Area (Rudman...
navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Kilauea East Rift Area (Rudman & Epp, 1983) Exploration Activity...
Math 496: Mathematical Models in Computational Biology ... - CECM
Math 496: Mathematical Models in Computational Biology. Lecture Notes for May 17 th. Section 1: Genome Rearrangements. During the process of an�...
Development of Medical Simulation Computer Models: Medical Ice...
Application in Advanced Laparoscopic Procedures Application in Emergency Response Current Research on Medical Slurry Cooling Development of Medical Simulation Computer Models...
Computational Modeling of Materials, Minerals and Metals Processing
R.S. Bellur-Ramaswamy, R. Haber, N.A. Sobh and D.A. Tortorelli. Computational Modelling of Thermomechanical Phenomena....................................................85.
Microsoft PowerPoint - Murray --- GAO Computer Modelling -- EM...
Director Office of Standards and Quality Assurance May 26, 2011 Print Close GAO-11-143 DOE Needs a Comprehensive Strategy and Guidance on Computer Models that Support...
New Computer Model Pinpoints Prime Materials for Carbon Capture
release and compression, and then developed a computer model to calculate this energy consumption for any material. Smit then obtained a database of 4 million zeolite...
Integrated Computational Modeling of Materials Joining and ...
... well as, progress made due to high performance computing infrastructure with examples. The examples will range from predictions of heat- and mass-transfer,�...
A leasing instances based billing model for cloud computing
As a new technology in IT industry, cloud computing has been much focused by both academia and industry. And many topics in cloud computing are under study. However, as one of the most important issue, billing and pricing has been not so much concerned. ... Keywords: billing model, cloud computing, leasing instances, pricing
Qin Yuan; Zhixiang Liu; Junjie Peng; Xing Wu; Jiandun Li; Fangfang Han; Qing Li; Wu Zhang; Xinjin Fan; Shengyuan Kong
A Computational Model of Mitigating Disease Spread in Spatial Networks
This study examines the problem of disease spreading and containment in spatial networks, where the computational model is capable of detecting disease progression to initiate processes mitigating infection spreads. This paper focuses on disease spread ... Keywords: Computational Epidemiology, Computer Viruses, Disease Progression, Forest Fires, Spatial Networks
Taehyong Kim; Kang Li; Aidong Zhang; Surajit Sen; Murali Ramanathan
Scaling up transit priority modelling using high-throughput computing
The optimization of Road Space Allocation (RSA) from a network perspective is computationally challenging. An analogue to the Network Design Problem (NDP), RSA can be classified NP-hard. In large-scale networks when the number of alternatives increases ... Keywords: genetic algorithm, high-performance computing, high-throughput computing, transport modelling
Mahmoud Mesbah, Majid Sarvi, Jefferson Tan, Fateme Karimirad
Stochastic computational models for accurate reliability evaluation of logic circuits
As reliability becomes a major concern with the continuous scaling of CMOS technology, several computational methodologies have been developed for the reliability evaluation of logic circuits. Previous accurate analytical approaches, however, have a ... Keywords: fault tolerance, logic circuits, reliability evaluation, stochastic computation, stochastic computational model
Hao Chen; Jie Han
Potential formal models for autonomic computing applications
An analysis of the potential formalism, used in the hierarchical system theory is performed, addressing the autonomic computing system design. In that manner, self management of the overall autonomic system can be achieved by influencing the local resources ... Keywords: autonomic computing systems, control theory, hierarchical system theory, optimization
Todor Stoilov; Krasimira Stoilova
Los Alamos CCS (Center for Computer Security) formal computer security model
This paper provides a brief presentation of the formal computer security model currently being developed at the Los Alamos Department of Energy (DOE) Center for Computer Security (CCS). The initial motivation for this effort was the need to provide a method by which DOE computer security policy implementation could be tested and verified. The actual analytical model was a result of the integration of current research in computer security and previous modeling and research experiences. The model is being developed to define a generic view of the computer and network security domains, to provide a theoretical basis for the design of a security model, and to address the limitations of present models. Formal mathematical models for computer security have been designed and developed in conjunction with attempts to build secure computer systems since the early 70's. The foundation of the Los Alamos DOE CCS model is a series of functionally dependent probability equations, relations, and expressions. The mathematical basis appears to be justified and is undergoing continued discrimination and evolution. We expect to apply the model to the discipline of the Bell-Lapadula abstract sets of objects and subjects. 5 refs.
Dreicer, J.S.; Hunteman, W.J. (Los Alamos National Lab., NM (USA))
Surveillance and human-computer interaction applications of self-growing models
The aim of the work is to build self-growing based architectures to support visual surveillance and human-computer interaction systems. The objectives include: identifying and tracking persons or objects in the scene or the interpretation of user gestures ... Keywords: Growing Neural Gas, Human-computer interaction, Self-growing models, Surveillance systems, Topology preservation
Jos� Garc�a-Rodr�guez; Juan Manuel Garc�a-Chamizo
3.320 Atomistic Computer Modeling of Materials, Spring 2003
Theory and application of atomistic computer simulations to model, understand, and predict the properties of real materials. Energy models, from classical potentials to first-principles approaches. Density-functional theory ...
Marzari, Nicola
Overview of ASC Capability Computing System Governance Model
This document contains a description of the Advanced Simulation and Computing Program's Capability Computing System Governance Model. Objectives of the Governance Model are to ensure that the capability system resources are allocated on a priority-driven basis according to the Program requirements; and to utilize ASC Capability Systems for the large capability jobs for which they were designed and procured.
Doebling, Scott W. [Los Alamos National Laboratory
Random matrix theory for modeling uncertainties in computational mechanics
Random matrix theory for modeling uncertainties in computational mechanics C. Soize Laboratory of Engineering Mechanics, University of Marne-la-Vall´ee, 5 boulevard Descartes, 77454 Marne-la-Vallée, France, e in computational mechanics. If data uncertainties can be modeled by parametric probabilistic methods, for a given
Applying High Performance Computing to Analyzing by Probabilistic Model Checking
Applying High Performance Computing to Analyzing by Probabilistic Model Checking Mobile Cellular on the use of high performance computing in order to analyze with the proba- bilistic model checker PRISM. The Figure Generation Script 22 2 #12;1. Introduction We report in this paper on the use of high performance
Schneider, Carsten
2006 Special Issue: Synthetic computational models of selective attention
Computational modeling plays an important role to understand the mechanisms of attention. In this framework, synthetic computational models can uniquely contribute to integrate different explanatory levels and neurocognitive findings, with special reference ... Keywords: Awareness, Meditation states, Processing levels, Selective attention, Synchronization
Antonino Raffone
Forecast Combinations of Computational Intelligence and Linear Models for the
Forecast Combinations of Computational Intelligence and Linear Models for the NN5 Time Series Forecasting competition Robert R. Andrawis Dept Computer Engineering Cairo University, Giza, Egypt firstname.lastname@example.com November 6, 2010 Abstract In this work we introduce a forecasting model with which we participated
Atiya, Amir
Pultrusion manufacturing process development by computational modelling and methods
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
Implementing and assessing computational modeling in introductory mechanics
Students taking introductory physics are rarely exposed to computational modeling. In a one-semester large lecture introductory calculus-based mechanics course at Georgia Tech, students learned to solve physics problems using the VPython programming environment. During the term 1357 students in this course solved a suite of fourteen computational modeling homework questions delivered using an online commercial course management system. Their proficiency with computational modeling was evaluated in a proctored environment using a novel central force problem. The majority of students (60.4%) successfully completed the evaluation. Analysis of erroneous student-submitted programs indicated that a small set of student errors explained why most programs failed. We discuss the design and implementation of the computational modeling homework and evaluation, the results from the evaluation and the implications for instruction in computational modeling in introductory STEM courses.
Caballero, Marcos D; Schatz, Michael F
This book is intended for a wide readership including engineers, ap plied mathematicians, computer scientists, and graduate students who
Preface This book is intended for a wide readership including engineers, ap plied mathematicians on the Lyapunov matrix equation. The book presents different techniques for solving and ana lyzing the algebraic interest. The book provides easy and quick references for the solution of many engineering and mathematical
Gajic, Zoran
An Earth Outgoing Longwave Radiation Climate Model. Part II: Radiation with Clouds Included
An Earth outgoing longwave radiation (OLWR) climate model was constructed for radiation budget studies. The model consists of the upward radiative transfer parameterization of Thompson and Warren, the cloud cover model of Sherr et al., and a ...
Shi-Keng Yang; G. Louis Smith; Fred L. Bartman
An Integrated Computational Model for Additive Manufacturing ...
As part of this integrated model, this paper describes a macroscopic thermo- mechanical modeling approach to simulate the layer-by-layer AM process to build�...
High accuracy power spectra including baryonic physics in dynamical Dark Energy models
The next generation mass probes will obtain information on non--linear power spectra P(k,z) and their evolution, allowing us to investigate the nature of Dark Energy. To exploit such data we need high precision simulations, extending at least up to scales of k\\simeq 10 h^-1 Mpc, where the effects of baryons can no longer be neglected. In this paper, we present a series of large scale hydrodynamical simulations for LCDM and dynamical Dark Energy (dDE) models, in which the equation of state parameter is z-dependent. The simulations include gas cooling, star formation and Supernovae feedback. They closely approximate the observed star formation rate and the observationally derived star/Dark Matter mass ratio in collapsed systems. Baryon dynamics cause spectral shifts exceeding 1% at k > 2-3 hMpc^-1 compared to pure n-body simulations in the LCDM simulations. This agrees with previous studies, although we find a smaller effect (~50%) on the power spectrum amplitude at higher k's. dDE exhibits similar behavior, ev...
Casarini, Luciano; Bonometto, Silvio A; Stinson, Greg S
Modeling Sea Ice as a Granular Material, Including the Dilatancy Effect
A dynamic sea ice model based on granular material rheology is presented. The sea ice model is coupled to both a mixed layer ocean model and a one-layer thermodynamic atmospheric model, which allows for an ice albedo feedback. Land is represented ...
L-B. Tremblay; L. A. Mysak
Modeling-Computer Simulations At Valles Caldera - Redondo Area (Roberts, Et
Modeling-Computer Simulations At Valles Caldera - Redondo Area (Roberts, Et Modeling-Computer Simulations At Valles Caldera - Redondo Area (Roberts, Et Al., 1995) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Valles Caldera - Redondo Area (Roberts, Et Al., 1995) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Modeling of the amplitude data, using the Aki-Lamer method, confirmed that this anomaly exists and we estimated quantitative parameters defining it. All model parameters were physically meaningful except for one. The value for Q inside the anomaly, required to explain the data, was unrealistically low. This was probably due to the inability to include additional
Computer modeling of ORNL storage tank sludge mobilization and mixing
This report presents and analyzes the results of the computer modeling of mixing and mobilization of sludge in horizontal, cylindrical storage tanks using submerged liquid jets. The computer modeling uses the TEMPEST computational fluid dynamics computer program. The horizontal, cylindrical storage tank configuration is similar to the Melton Valley Storage Tanks (MVST) at Oak Ridge National (ORNL). The MVST tank contents exhibit non-homogeneous, non-Newtonian rheology characteristics. The eventual goals of the simulations are to determine under what conditions sludge mobilization using submerged liquid jets is feasible in tanks of this configuration, and to estimate mixing times required to approach homogeneity of the contents of the tanks.
Terrones, G.; Eyler, L.L.
Computationally efficient nonlinear predictive control based on neural Wiener models
This paper describes a computationally efficient nonlinear model predictive control (MPC) algorithm based on neural Wiener models and its application. The model contains a linear dynamic part in series with a steady-state nonlinear part which is realised ... Keywords: Linearisation, Model predictive control, Neural networks, Optimisation, Process control, Wiener systems
Maciej ?awry?czuk
HELIOS: a computational model for solar concentrators
HELIOS is a computer code for mathematically simulating the behavior of the flux pattern from the concentrator field for a solar central receiver power station. Statistical methods are used to incorporate nondeterministic factors. The code is described, and some examples of its output are given.
Biggs, F.; Vittitoe, C.N.
A Compact Propagation Delay Model for Deep-Submicron CMOS Gates including Crosstalk
We present a compact, fully physical, analytical model for the propagation delay and the output transition time of deep-submicron CMOS gates. The model accounts for crosstalk effects, short-circuit currents, the input-output coupling capacitance and ...
J. L. Rossell�; J. Segura
Modeling-Computer Simulations (Combs, Et Al., 1999) | Open Energy
Modeling-Computer Simulations (Combs, Et Al., 1999) Modeling-Computer Simulations (Combs, Et Al., 1999) Exploration Activity Details Location Unspecified Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Various models/simulations used to analyze data obtained from slimhole drilling. References Jim Combs, John T. Finger, Colin Goranson, Charles E. Hockox Jr., Ronald D. Jacobsen, Gene Polik (1999) Slimhole Handbook- Procedures And Recommendations For Slimhole Drilling And Testing In Geothermal Exploration Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_(Combs,_Et_Al.,_1999)&oldid=387232" Category: Exploration Activities What links here Related changes Special pages Printable version Permanent link Browse properties
Transforming High School Physics with Modeling and Computation
The Engage to Excel (PCAST) report, the National Research Council's Framework for K-12 Science Education, and the Next Generation Science Standards all call for transforming the physics classroom into an environment that teaches students real scientific practices. This work describes the early stages of one such attempt to transform a high school physics classroom. Specifically, a series of model-building and computational modeling exercises were piloted in a ninth grade Physics First classroom. Student use of computation was assessed using a proctored programming assignment, where the students produced and discussed a computational model of a baseball in motion via a high-level programming environment (VPython). Student views on computation and its link to mechanics was assessed with a written essay and a series of think-aloud interviews. This pilot study shows computation's ability for connecting scientific practice to the high school science classroom.
Aiken, John M
Several Computational Opportunities and Challenges Associated with Climate Change Modeling
One of the key factors in the improved understanding of climate science is the development and improvement of high fidelity climate models. These models are critical for projections of future climate scenarios, as well as for highlighting the areas where further measurement and experimentation are needed for knowledge improvement. In this paper, we focus on several computing issues associated with climate change modeling. First, we review a fully coupled global simulation and a nested regional climate model to demonstrate key design components, and then we explain the underlying restrictions associated with the temporal and spatial scale for climate change modeling. We then discuss the role of high-end computers in climate change sciences. Finally, we explain the importance of fostering regional, integrated climate impact analysis. Although we discuss the computational challenges associated with climate change modeling, and we hope those considerations can also be beneficial to many other modeling research programs involving multiscale system dynamics.
Computational mechanical modeling of the behavior of carbon nanotubes
This paper presents a computational method for the mechanical simulation of carbon nanotubes, whose complexity is linear on the number of atoms. The regularity of a graphene lattice at its energy ground permits the definition of a tiling scheme that ... Keywords: carbon nanotubes, computational method, mathematical modeling, molecular dynamics, numerical simulation
Maria Morandi Cecchi; Alberto Giovanni Busetto
Modeling and experimental validation of internal faults in salient pole synchronous machines including space harmonics
Considering the space harmonics caused by the faulted windings, a simulation model of internal faults in salient pole synchronous machines is proposed in this paper. The model is based on the winding function approach, which makes no assumption for sinusoidal ... Keywords: Internal faults, Space harmonics, Synchronous machines, Winding function
X. Tu; L. -A. Dessaint; M. El Kahel; A. Barry
Serial model for attack tree computations
In this paper we extend the standard attack tree model by introducing temporal order to the attacker's decision making process. This will allow us to model the attacker's behaviour more accurately, since this way it is possible to study his actions related ...
Aivo J�rgenson; Jan Willemson
LANL researchers use computer modeling to study HIV | National Nuclear
National Nuclear Security Administration (NNSA)
researchers use computer modeling to study HIV | National Nuclear researchers use computer modeling to study HIV | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > LANL researchers use computer modeling to study HIV LANL researchers use computer modeling to study HIV Posted By Office of Public Affairs Los Alamos National Laboratory researchers are investigating the complex
Computer simulation and topological modeling of radiation effects in zircon
The purpose of this study is to understand on atomic level the structural response of zircon (ZrSiO4) to irradiation using molecular dynamics (MD) computer simulations, and to develop topological models that can describe ...
Zhang, Yi, 1979-
Computational model design and performance estimation in registration brake control
Electric motorcycles are applicable to both toys and real motorcycles, and also is a reference for constructing larger electrical vehicles. A design computational model of regenerative braking control of electric motorcycles and an experimental identification ...
P. S. Pa; S. C. Chang
15.094 Systems Optimization: Models and Computation, Spring 2002
A computational and application-oriented introduction to the modeling of large-scale systems in a wide variety of decision-making domains and the optimization of such systems using state-of-the-art optimization software. ...
Freund, Robert Michael
OREMPdb: a semantic dictionary of computational pathway models
Background The information coming from biomedical ontologies and computational pathway models is expanding continuously: research communities keep this process up and their advances are generally shared by means of dedicated ...
Umeton, Renato
DOE Issues Funding Opportunity for Advanced Computational and Modeling
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Funding Opportunity for Advanced Computational and Funding Opportunity for Advanced Computational and Modeling Research for the Electric Power System DOE Issues Funding Opportunity for Advanced Computational and Modeling Research for the Electric Power System May 23, 2012 - 8:36am Addthis The objective of this Funding Opportunity Announcement (FOA) is to leverage scientific advancements in mathematics and computation for application to power system models and software tools, with the long-term goal of enabling real-time protection and control based on wide-area sensor measurements. Specifically, this FOA focuses on two foundational research challenges: 1) handling of large data sets to improve suitability for operational (and/or planning) models and analysis; and 2) "faster than real-time" simulations that improve understanding of
Low Dose Radiation Research Program: Use of Computational Modeling to
Use of Computational Modeling to Evaluate Hypotheses about the Use of Computational Modeling to Evaluate Hypotheses about the Molecular and Cellular Mechanisms of Bystander Effects Authors: Yuchao âMaggieâ Zhao and Rory Conolly Institutions: CIIT Centers for Health Research, 6 Davis Drive, Research Triangle Park, North Carolina A detailed understanding of the biological mechanisms of radiation-induced damage at the molecular and cellular levels is needed for accurate assessment of the shape of the dose-response curve for radiationinduced health effects in the intact organism. Computational models can contribute to the improved understanding of mechanisms through integration of data and quantitative evaluation of hypotheses. We propose to develop a novel computational model of bystander effects elicited by oxidative stress and a
Modeling and Controller Design of a Wind Energy Conversion System Including a Matrix Converter.
??In this thesis, a grid-connected wind-energy converter system including a matrix converter is proposed. The matrix converter, as a power electronic converter, is used to� (more)
Barakati, Seyed Masoud
Eta Model Precipitation Forecasts for a Period Including Tropical Storm Allison
A step-mountain (eta) coordinate limited-area model is being developed at the National Meteorological Center (NMC) to improve forecasts of severe weather and other mesoscale phenomena. Precipitation forecasts are reviewed for the 20-day period 16 ...
Fedor Mesinger; Thomas L. Black; David W. Plummer; John H. Ward
Land Surface Hydrology Parameterization for Atmospheric General Circulation models Including Subgrid Scale Spatial Variability
Parameterizations are developed for the representation of subgrid hydrologic processes in atmospheric general circulation models. Reasonable a priori probability density functions of the spatial variability of soil moisture and of precipitation ...
D. Entekhabi; P. S. Eagleson
Computational Modeling of Materials, Minerals, and Metals
Feb 1, 2002 ... 249-250]A Model of the Cathode Dynamics in Electric Field-Enhanced Smelting and Refining of Steel[pp. ... TMS Student Member price: 721.00.
Computational load in model physics of the parallel NCAR community climate model
Maintaining a balance of computational load over processors is a crucial issue in parallel computing. For efficient parallel implementation, complex codes such as climate models need to be analyzed for load imbalances. In the present study we focus on the load imbalances in the physics portion of the community climate model`s (CCM2) distributed-memory parallel implementation on the Intel Touchstone DELTA computer. We note that the major source of load imbalance is the diurnal variation in the computation of solar radiation. Convective weather patterns also cause some load imbalance. Land-ocean contrast is seen to have little effect on computational load in the present version of the model.
Michalakes, J.G.; Nanjundiah, R.S.
Modeling-Computer Simulations At Cove Fort Area (Toksoz, Et Al, 2010) |
Modeling-Computer Simulations At Cove Fort Area (Toksoz, Et Al, 2010) Modeling-Computer Simulations At Cove Fort Area (Toksoz, Et Al, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Cove Fort Area (Toksoz, Et Al, 2010) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes We have collected various geophysical data around the geothermal field, including heat flow, gravity, MT, seismic surface wave phase and group velocity maps, seismic body wave travel time data and full seismic waveforms. All of these geophysical data sets have different strengths on characterizing subsurface structures and properties. Combining these data through a coordinated analysis and, when possible, by joint inversion
Interactive computational models of particle dynamics using virtual reality
An increasing number of industrial applications rely on computational models to reduce costs in product design, development, and testing cycles. Here, the authors discuss an interactive environment for the visualization, analysis, and modification of computational models used in industrial settings. In particular, they focus on interactively placing massless, massed, and evaporating particulate matter in computational fluid dynamics applications.they discuss the numerical model used to compute the particle pathlines in the fluid flow for display and analysis. They briefly describe the toolkits developed for vector and scalar field visualization, interactive particulate source placement, and a three-dimensional GUI interface. This system is currently used in two industrial applications, and they present the tools in the context of these applications. They summarize the current state of the project and offer directions for future research.
Canfield, T.; Diachin, D.; Freitag, L.; Heath, D.; Herzog, J. [Argonne National Lab., IL (United States); Michels, W. [Nalco Fuel Tech, Naperville, IL (United States)
Revisions to the hydrogen gas generation computer model
Waste Management Technology has requested SRTC to maintain and extend a previously developed computer model, TRUGAS, which calculates hydrogen gas concentrations within the transuranic (TRU) waste drums. TRUGAS was written by Frank G. Smith using the BASIC language and is described in the report A Computer Model of gas Generation and Transport within TRU Waste Drums (DP- 1754). The computer model has been partially validated by yielding results similar to experimental data collected at SRL and LANL over a wide range of conditions. The model was created to provide the capability of predicting conditions that could potentially lead to the formation of flammable gas concentrations within drums, and to assess proposed drum venting methods. The model has served as a tool in determining how gas concentrations are affected by parameters such as filter vent sizes, waste composition, gas generation values, the number and types of enclosures, water instrusion into the drum, and curie loading. The success of the TRUGAS model has prompted an interest in the program`s maintenance and enhancement. Experimental data continues to be collected at various sites on such parameters as permeability values, packaging arrangements, filter designs, and waste contents. Information provided by this data is used to improve the accuracy of the model`s predictions. Also, several modifications to the model have been made to enlarge the scope of problems which can be analyzed. For instance, the model has been used to calculate hydrogen concentrations inside steel cabinets containing retired glove boxes (WSRC-RP-89-762). The revised TRUGAS computer model, H2GAS, is described in this report. This report summarizes all modifications made to the TRUGAS computer model and provides documentation useful for making future updates to H2GAS.
Jerrell, J.W.
Computer models are abstractions of physical reality and are routinely used for solving practical engineering problems. These models are prepared using large complex computer codes that are widely used in the industry. Patran/Thermal is such a finite element computer code that is used for solving complex heat transfer problems in the industry. Finite element models of complex problems involve making assumptions and simplifications that depend upon the complexity of the problem and upon the judgment of the analysts. The assumptions involve mesh size, solution methods, convergence criteria, material properties, boundary conditions, etc. that could vary from analyst to analyst. All of these assumptions are, in fact, candidates for a purposeful and intended effort to systematically vary each in connection with the others to determine there relative importance or expected overall effect on the modeled outcome. These kinds of models derive from the methods of statistical science and are based on the principles of experimental designs. These, as all computer models, must be validated to make sure that the output from such an abstraction represents reality [1,2]. A new nuclear material packaging design, called 9977, which is undergoing a certification design review, is used to assess the capability of the Patran/Thermal computer model to simulate 9977 thermal response. The computer model for the 9977 package is validated by comparing its output with the test data collected from an actual thermal test performed on a full size 9977 package. Inferences are drawn by performing statistical analyses on the residuals (test data--model predictions).
Gupta, N; Gene Shine, G; Cary Tuckfield, C
Computational Fuel Cell Research and SOFC Modeling at Penn State
Computational Fuel Cell Research and SOFC Modeling at Penn State Chao-Yang Wang Professor of PEM Fuel Cells SOFC Modeling & Simulation Fuel Cell Controls Summary #12;ECEC Overview Vision: provide, DMFC, and SOFC #12;ECEC Facilities (>5,000 sq ft) Fuel Cell/Battery Experimental Labs Fuel Cell
DYNASTORE - A Computer Model for Quantifying Dynamic Energy Storage Benefits
Now in development, the DYNASTORE computer model is the first production cost model designed to accurately represent changes in the utility daily load. By quantifying the dynamic benefits of energy storage, it highlights the significant cost savings linked with this technology.
Computational challenges in large-scale air pollution modelling
Many difficulties must be overcome when large-scale air pollution models are treated numerically, because the physical and chemical processes in the atmosphere are very fast. This is why it is necessary to use a large space domain in order ... Keywords: air pollution models, finite elements, ordinary differential equations, parallel computational, partial differential equations, quasi-steady-state-approximation
Tzvetan Ostromsky; Wojciech Owczarz; Zahari Zlatev
Modelling of a Utility Boiler Using Parallel Computing
A mathematical model for the simulation of the turbulent reactive flow and heat transfer in a power station boiler has been parallelized. The mathematical model is based on the numerical solution of the governing equations for mass, momentum, energy ... Keywords: boilers, computational fluid dynamics, discrete ordinates, parallel processing, radiative heat transfer, turbulent reactive flows
P. J. Coelho; P. A. Novo; M. G. Carvalho
Computational approaches to model the phase behaviour of
system with uniform physical and chemical characteristics . #12;The phase diagram of water 15 ice of water models (i.e.various conditions, ice phases)! #12;Less attention received for solid water untilComputational approaches to model the phase behaviour of molecular liquids and solids: water
Kjelstrup, Signe
A computer simulation model for examining cogeneration alternatives
The purpose of this paper is to describe a computer simulation model that was used to analyze the technical and economic aspects of specific cogeneration applications. The model was coded in the APL language and runs on the Scientific Time Sharing System. ...
P. F. Schweizer; R. E. Sieck
DEUS Computer Evaluation Model, Volume 1: Program Descriptive Manual
This report presents DEUS, a computer simulation model of duel energy use systems. The model is designed for the evaluation of cogeneration systems and is a useful tool for utilities as well as cogenerators. Volume 1 describes the program methodology and its data base; Volume 2 is a user's manual.
Increasing NOAA's computational capacity to improve global forecast modeling
1 Increasing NOAA's computational capacity to improve global forecast modeling A NOAA of the NWS's forecast products, even its regional forecast products, are constrained by the limitations of NOAA's global forecast model. Unfortunately, our global forecasts are less accurate than those from
Hamill, Tom
Decreasing Computational Time of Urban Cellular Automata Through Model Portability
This paper investigates how portability of a model between different computer operating systems can lead to increased efficiency in code execution. The portability problem is not a trivial one, as many geographic models are designed to be run inside ... Keywords: Calibration, Cellular automata, Portability
Charles Dietzel; Keith C. Clarke
A computationally efficient method of identifying generic fuzzy models
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
Modeling-Computer Simulations (Ozkocak, 1985) | Open Energy Information
Ozkocak, 1985) Ozkocak, 1985) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations (Ozkocak, 1985) Exploration Activity Details Location Unspecified Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes CONTRIBUTION OF THE LATEST ADVANCES IN GEOLOGY, GEOCHEMISTRY AND GEOPHYSICS TO GEOTHERMAL PROSPECTING. Twenty-five papers were received on this topic, 14 of them concerning geology, four geochemistry and seven geophysics. The papers dealing with geology describe attempts to build models of underground geothermal activity and study the factors that control the formation of reservoir and cap rocks (regional plate tectonics, local tectonics, stratigraphy, geochemistry and volcanism) and the relations
Waste Management Technology has requested SRTC to maintain and extend a previously developed computer model, TRUGAS, which calculates hydrogen gas concentrations within the transuranic (TRU) waste drums. TRUGAS was written by Frank G. Smith using the BASIC language and is described in the report A Computer Model of gas Generation and Transport within TRU Waste Drums (DP- 1754). The computer model has been partially validated by yielding results similar to experimental data collected at SRL and LANL over a wide range of conditions. The model was created to provide the capability of predicting conditions that could potentially lead to the formation of flammable gas concentrations within drums, and to assess proposed drum venting methods. The model has served as a tool in determining how gas concentrations are affected by parameters such as filter vent sizes, waste composition, gas generation values, the number and types of enclosures, water instrusion into the drum, and curie loading. The success of the TRUGAS model has prompted an interest in the program's maintenance and enhancement. Experimental data continues to be collected at various sites on such parameters as permeability values, packaging arrangements, filter designs, and waste contents. Information provided by this data is used to improve the accuracy of the model's predictions. Also, several modifications to the model have been made to enlarge the scope of problems which can be analyzed. For instance, the model has been used to calculate hydrogen concentrations inside steel cabinets containing retired glove boxes (WSRC-RP-89-762). The revised TRUGAS computer model, H2GAS, is described in this report. This report summarizes all modifications made to the TRUGAS computer model and provides documentation useful for making future updates to H2GAS.
Modeling-Computer Simulations (Lewicki & Oldenburg, 2004) | Open Energy
Modeling-Computer Simulations (Lewicki & Oldenburg, Modeling-Computer Simulations (Lewicki & Oldenburg, 2004) Exploration Activity Details Location Unspecified Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes In this section we present numerical simulations of CO2 migration, seepage, and atmospheric dispersion. The purpose of these simulations is to evaluate the magnitudes and form of anomalous CO2 concentrations and fluxes that might be expected to emanate from a given model hidden geothermal system. From this information, we can design and evaluate potential monitoring and detection methods. References Jennifer L. Lewicki, Curtis M. Oldenburg (2004) Strategies For Detecting Hidden Geothermal Systems By Near-Surface Gas Monitoring Retrieved from
Wilt & Haar, 1986) Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Valles Caldera - Sulphur Springs Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Sulphur Springs Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting gravity observations along profiles A--A' and B--B' (Talwani et al., 1959). Densities of 2.12, 2.40, and 2.65 g/cm a were used for modeling the near-surface caldera fill, the underlying volcanics, and the basement sections, respectively (Fig. 8). Although correlation with well data was done whenever possible, there is some uncertainty to the
Methodology for characterizing modeling and discretization uncertainties in computational simulation
This research effort focuses on methodology for quantifying the effects of model uncertainty and discretization error on computational modeling and simulation. The work is directed towards developing methodologies which treat model form assumptions within an overall framework for uncertainty quantification, for the purpose of developing estimates of total prediction uncertainty. The present effort consists of work in three areas: framework development for sources of uncertainty and error in the modeling and simulation process which impact model structure; model uncertainty assessment and propagation through Bayesian inference methods; and discretization error estimation within the context of non-deterministic analysis.
Low Dose Radiation Research Program: Computational Modeling of Biochemical
Computational Modeling of Biochemical Pathways Linking Ionizing Computational Modeling of Biochemical Pathways Linking Ionizing Radiation to Cell Cycle Arrest, Apoptosis, and Tumor Incidence Authors: Yuchao Maggie Zhao and Rory Conolly Institutions: Center for Computational Systems Biology CIIT Centers for Health Research Long-Range Goal: To develop an integrated, computational framework for the prediction of low-dose-response to ionizing radiation (IR) in people. Methodology: To provide a flexible framework to evaluate mechanisms of cellular adaptive responses after exposure to IR, three progressively more complicated descriptions of biochemical pathways linking DNA damage with cell-cycle checkpoint control and apoptosis were developed. These descriptions focus on p53-dependent checkpoint arrest and apoptosis, p73-dependent apoptosis, and Chk2-dependent checkpoint arrest,
A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus
This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.
Raustad, Richard A. [Florida Solar Energy Center
Nuclear Reactor/Hydrogen Process Interface Including the HyPEP Model
The Nuclear Reactor/Hydrogen Plant interface is the intermediate heat transport loop that will connect a very high temperature gas-cooled nuclear reactor (VHTR) to a thermochemical, high-temperature electrolysis, or hybrid hydrogen production plant. A prototype plant called the Next Generation Nuclear Plant (NGNP) is planned for construction and operation at the Idaho National Laboratory in the 2018-2021 timeframe, and will involve a VHTR, a high-temperature interface, and a hydrogen production plant. The interface is responsible for transporting high-temperature thermal energy from the nuclear reactor to the hydrogen production plant while protecting the nuclear plant from operational disturbances at the hydrogen plant. Development of the interface is occurring under the DOE Nuclear Hydrogen Initiative (NHI) and involves the study, design, and development of high-temperature heat exchangers, heat transport systems, materials, safety, and integrated system models. Research and development work on the system interface began in 2004 and is expected to continue at least until the start of construction of an engineering-scale demonstration plant.
Steven R. Sherman
Systems, methods and computer-readable media to model kinetic performance of rechargeable electrochemical devices
DOE Patents (OSTI)
A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics. The computing system also analyzes the cell information of the electrochemical cell with a Butler-Volmer (BV) expression modified to determine exchange current density of the electrochemical cell by including kinetic performance information related to pulse-time dependence, electrode surface availability, or a combination thereof. A set of sigmoid-based expressions may be included with the modified-BV expression to determine kinetic performance as a function of pulse time. The determined exchange current density may be used with the modified-BV expression, with or without the sigmoid expressions, to analyze other characteristics of the electrochemical cell. Model parameters can be defined in terms of cell aging, making the overall kinetics model amenable to predictive estimates of cell kinetic performance along the aging timeline.
Gering, Kevin L.
Carbonaceous Chemistry for Computational Modeling Licensing and Partnership Opportunity
Chemistry for Computational Modeling Chemistry for Computational Modeling Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) has developed a software platform entitled Carbonaceous Chemistry for Computational Modeling (C3M) that is used to access a variety of kinetic processes and reaction mechanisms typically found in coal gasification, gas clean-up, and carbon capture processes. This unique software provides the user the ability to conduct virtual kinetic experiments using leading kinetic packages and available experimental data to evaluate kinetic predictions as a function of fuel and sorbent type and/or operating conditions. A Patent Cooperation Treaty application was filed in June 2008. NETL is seeking non-exclusive licensing partners interested in implementing
Develop baseline computational model for proactive welding stress
Develop baseline computational model for proactive welding stress Develop baseline computational model for proactive welding stress management to suppress helium induced cracking during weld repair Develop baseline computational model for proactive welding stress management to suppress helium induced cracking during weld repair There are over 100 nuclear power plants operating in the U.S., which generate approximately 20% of the nation's electricity. These plants range from 15 to 40 years old. Extending the service lives of the current fleet of nuclear power plants beyond 60 years is imperative to allow for the environmentally-sustainable energy infrastructure being developed and matured. Welding repair of irradiated nuclear reactor materials (such as austenitic stainless steels) is especially challenging because of the
Computer modeling reveals how surprisingly potent hepatitis C drug works
Hepatitis C computer modeling Hepatitis C computer modeling Computer modeling reveals how surprisingly potent hepatitis C drug works A study reveals how daclatasvir targets one of its proteins and causes the fastest viral decline ever seen with anti-HCV drugs - within 12 hours of treatment. February 19, 2013 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.
Modeling-Computer Simulations (Laney, 2005) | Open Energy Information
Modeling-Computer Simulations (Laney, 2005) Modeling-Computer Simulations (Laney, 2005) Exploration Activity Details Location Unspecified Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Design of Sampling Strategies to Detect CO2 Emissions From Hidden Geothermal Systems, Lewicki, Oldenburg and Kennedy. The objective of this project is to investigate geothermal CO2 monitoring in the near surface as a tool to discover hidden geothermal reservoirs. A primary goal of this project is to develop an approach that places emphasis on cost and time-efficient near-surface exploration methods and yields results to guide and focus more cost-intensive geophysical measurements, installation of deep wells, and geochemical analyses of deep fluids. To this end, we
Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices
A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.
Gering, Kevin L
Modeling and analysis of transient vehicle underhood thermo - hydrodynamic events using computational fluid dynamics and high performance computing.
This work has explored the preliminary design of a Computational Fluid Dynamics (CFD) tool for the analysis of transient vehicle underhood thermo-hydrodynamic events using high performance computing platforms. The goal of this tool will be to extend the capabilities of an existing established CFD code, STAR-CD, allowing the car manufacturers to analyze the impact of transient operational events on the underhood thermal management by exploiting the computational efficiency of modern high performance computing systems. In particular, the project has focused on the CFD modeling of the radiator behavior during a specified transient. The 3-D radiator calculations were performed using STAR-CD, which can perform both steady-state and transient calculations, on the cluster computer available at ANL in the Nuclear Engineering Division. Specified transient boundary conditions, based on experimental data provided by Adapco and DaimlerChrysler were used. The possibility of using STAR-CD in a transient mode for the entire period of time analyzed has been compared with other strategies which involve the use of STAR-CD in a steady-state mode at specified time intervals, while transient heat transfer calculations would be performed for the rest of the time. The results of these calculations have been compared with the experimental data provided by Adapco/DaimlerChrysler and recommendations for future development of an optimal strategy for the CFD modeling of transient thermo-hydrodynamic events have been made. The results of this work open the way for the development of a CFD tool for the transient analysis of underhood thermo-hydrodynamic events, which will allow the integrated transient thermal analysis of the entire cooling system, including both the engine block and the radiator, on high performance computing systems.
Froehle, P.; Tentner, A.; Wang, C.
Modeling and analysis of transient vehicle underhood thermo- hydrodynamic events using computational fluid dynamics and high performance computing.
Tentner, A.; Froehle, P.; Wang, C.; Nuclear Engineering Division
CDIAC catalog of numeric data packages and computer model packages
The Carbon Dioxide Information Analysis Center acquires, quality-assures, and distributes to the scientific community numeric data packages (NDPs) and computer model packages (CMPs) dealing with topics related to atmospheric trace-gas concentrations and global climate change. These packages include data on historic and present atmospheric CO{sub 2} and CH{sub 4} concentrations, historic and present oceanic CO{sub 2} concentrations, historic weather and climate around the world, sea-level rise, storm occurrences, volcanic dust in the atmosphere, sources of atmospheric CO{sub 2}, plants` response to elevated CO{sub 2} levels, sunspot occurrences, and many other indicators of, contributors to, or components of climate change. This catalog describes the packages presently offered by CDIAC, reviews the processes used by CDIAC to assure the quality of the data contained in these packages, notes the media on which each package is available, describes the documentation that accompanies each package, and provides ordering information. Numeric data are available in the printed NDPs and CMPs, in CD-ROM format, and from an anonymous FTP area via Internet. All CDIAC information products are available at no cost.
Boden, T.A. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; O`Hara, F.M. Jr. [O`Hara (Fred M., Jr.), Oak Ridge, TN (US); Stoss, F.W. [Univ. of Tennessee, Knoxville, TN (US). Energy, Environment, and Resources Center
Modeling-Computer Simulations At Dixie Valley Geothermal Field Area
Dixie Valley Geothermal Field Area Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes Using a simple one-dimensional steady-state fluid flow model, the helium content and isotopic composition imply vertical fluid flow rates from the mantle of _7 mm/yr. This is a strict lower limit to the fluid flow rate: the one-dimensional model does not consider diffusive re-distribution of helium or mixing with water containing only a crustal helium component and
Agent-based computational models and generative social science
This article argues that the agent-based computational model permits a distinctive approach to social science for which the term �generative � is suitable. In defending this terminology, features distinguishing the approach from both �inductive � and �deductive � science are given. Then, the following specific contributions to social science are discussed: The agent-based computational model is a new tool for empirical research. It offers a natural environment for the study of connectionist phenomena in social science. Agent-based modeling provides a powerful way to address certain enduring�and especially interdisciplinary�questions. It allows one to subject certain core theories�such as neoclassical microeconomics�to important types of stress (e.g., the effect of evolving preferences). It permits one to study how rules of individual behavior give rise�or �map up��to macroscopic regularities and organizations. In turn, one can employ laboratory behavioral research findings to select among competing agent-based (�bottom up�) models. The agent-based approach may well have the important effect of decoupling individual rationality from macroscopic equilibrium and of separating decision science from social science more generally. Agent-based modeling offers powerful new forms of hybrid theoretical-computational work; these are particularly relevant to the study of non-equilibrium systems. The agentbased approach invites the interpretation of society as a distributed computational device, and in turn the interpretation of social dynamics as a type of computation. This interpretation raises important foundational issues in social science�some related to intractability, and some to undecidability proper. Finally, since �emergence� figures prominently in this literature, I take up the connection between agent-based modeling and classical emergentism, criticizing the latter and arguing that the two are incompatible. ? 1999 John Wiley &
Joshua M. Epstein
innovati nNREL Computer Models Integrate Wind Turbines with
innovati nNREL Computer Models Integrate Wind Turbines with Floating Platforms Far off the shores for today's seabed-mounted offshore wind turbines. For the United States to tap into these vast offshore wind energy resources, wind turbines must be mounted on floating platforms to be cost effective
Computer Modeling of Carbon Metabolism Enables Biofuel Engineering (Fact Sheet)
In an effort to reduce the cost of biofuels, the National Renewable Energy Laboratory (NREL) has merged biochemistry with modern computing and mathematics. The result is a model of carbon metabolism that will help researchers understand and engineer the process of photosynthesis for optimal biofuel production.
Not Available
Applications of computer modeling at Wrightson, Johnson, Haddon & Williams, Inc
Computer modeling has become useful as an investigative tool and as a client communication and explanation tool in the field of acoustical consulting. A variety of in?house developed and commercially available applications is in constant use at the firm of Wrightson
UPDATE February 2012 - The Food Crises: Predictive validation of a quantitative model of food prices including speculators and ethanol conversion
Increases in global food prices have led to widespread hunger and social unrest---and an imperative to understand their causes. In a previous paper published in September 2011, we constructed for the first time a dynamic model that quantitatively agreed with food prices. Specifically, the model fit the FAO Food Price Index time series from January 2004 to March 2011, inclusive. The results showed that the dominant causes of price increases during this period were investor speculation and ethanol conversion. The model included investor trend following as well as shifting between commodities, equities and bonds to take advantage of increased expected returns. Here, we extend the food prices model to January 2012, without modifying the model but simply continuing its dynamics. The agreement is still precise, validating both the descriptive and predictive abilities of the analysis. Policy actions are needed to avoid a third speculative bubble that would cause prices to rise above recent peaks by the end of 2012.
Modeling-Computer Simulations At Yellowstone Region (Laney, 2005) | Open
Laney, 2005) Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Yellowstone Region (Laney, 2005) Exploration Activity Details Location Yellowstone Caldera Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes Localized Strain as a Discriminator of Hidden Geothermal Systems, Vasco and Foxall, 2005. Recent work has focused on (1) collaborating with Alessandro Ferretti to use Permanent Scatterer (PS) InSAR data to infer strain at depth, (2) working with Lane Johnson to develop a dynamic faulting model, and (3) acquiring InSAR data for the region surrounding the Dixie Valley fault zone in collaboration with Dr. William Foxall of LLNL. The InSAR data
Modeling-Computer Simulations At Central Nevada Seismic Zone Region
Central Nevada Seismic Zone Region Central Nevada Seismic Zone Region (Blackwell, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Central Nevada Seismic Zone Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to understand the nature of large scale constraints on the location and characteristics of the geothermal systems References D. D. Blackwell, K. W. Wisian, M. C. Richards, Mark Leidig, Richard Smith, Jason McKenna (2003) Geothermal Resource Analysis And Structure Of
Modeling-Computer Simulations At Raft River Geothermal Area (1979) | Open
Jump to: navigation, search Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Raft River Geothermal Area (1979) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1979 Usefulness useful DOE-funding Unknown Exploration Basis To evaluate the hydrodynamics of the unconfined aquifer. Notes This study covers about 1000 mi2 (2600 km2) of the southern Raft River drainage basin in south-central Idaho and northwest Utah. The main area of interest, approximately 200 mi2 (520 km2) of semiarid agricultural and rangeland in the southern Raft River Valley that includes the known Geothermal Resource Area near Bridge, Idaho, was modelled numerically. Computed and estimated transmissivity values range from 1200 ft2 per day
Scientists model brain structure to help computers recognize objects
Do you see what I see? Do you see what I see? Scientists model brain structure to help computers recognize objects The team tried developing a computer model based on human neural structure and function, to do what we do, and possibly do it better. December 20, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.
Martin Karplus and Computer Modeling for Chemical Systems
Office of Scientific and Technical Information (OSTI)
Martin Karplus and Computer Modeling for Chemical Systems Martin Karplus and Computer Modeling for Chemical Systems Resources with Additional Information · Karplus Equation Martin Karplus ©Portrait by N. Pitt, 9/10/03 Martin Karplus, the Theodore William Richards Professor of Chemistry Emeritus at Harvard, is one of three winners of the 2013 Nobel Prize in chemistry... The 83-year-old Vienna-born theoretical chemist, who is also affiliated with the Université de Strasbourg, Strasbourg, France, is a 1951 graduate of Harvard College and earned his Ph.D. in 1953 at the California Institute of Technology. While there, he worked with two-time Nobel laureate Linus Pauling, whom Karplus described as an important early influence. He shared the Nobel with researchers Michael Levitt of Stanford University and Arieh Warshel of the University of Southern California, Los Angeles. Warshel was once a postdoctoral student of Karplus ...
Use of high performance computing resources for underwater acoustic modeling.
The majority of standard underwater propagation models provide a two?dimensional (range and depth) acoustic field for a single frequency point source. Computational resource demand increases considerably when the three?dimensional acoustic field of a broad?band spatially extended source is of interest. An upgrade of the standard parabolic equationmodel RAM for use in a high?performance computing (HPC) environment is discussed. A benchmarked upgraded version of RAM is used in the Louisiana Optical Network Initiative HPC?environment to model the three?dimensional acoustic field of a seismic airgun array. Four?dimensional visualization (time and space) of the generated data volume is also addressed. [Research supported by the Louisiana Optical Network Initiative
Anca M. Niculescu; Natalia A. Sidorovskaia; Peter Achi; Arslan M. Tashmukhambetov; George E. Ioup; Juliette W. Ioup
The objective if this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The computed time averaged particle velocities and concentrations agree with PIV measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. This phase of the work was presented at the Chemical Reaction Engineering VIII: Computational Fluid Dynamics, August 6-11, 2000 in Quebec City, Canada. To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. The results together with simulations will be presented at the annual meeting of AIChE in November 2000.
Paul Lam; Dimitri Gidaspow
Advances in bayesian modelling and computation: spatio-temporal processes, model assessment and adaptive mcmc
The modelling and analysis of complex stochastic systems with increasingly large data sets, state-spaces and parameters provides major stimulus to research in Bayesian nonparametric methods and Bayesian computation. This dissertation presents ...
Chunlin Ji / Mike West
Introduction to the Report "Interlanguages and Synchronic Models of Computation."
Final Report for Integrated Multiscale Modeling of Molecular Computing Devices
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.
Bipole-dipole interpretation with three-dimensional models (including a field study of Las Alturas, New Mexico)
The bipole-dipole responses of three-dimensional (3D) prisms were studied using an integral equation numerical solution. Although response patterns are quite complex, the bipole-dipole method appears to be a useful, efficient means of mapping the areal distribution of resistivity. However, 3D modeling is required for quantitative interpretation. Computer time for our solution varies from negligible for small bodies to 6 minutes on a UNIVAC 1108 for the largest possible body (85 cubes). Bipole-dipole response varies significantly with bipole orientation and position, but simply changing the distance between the bipole and the body does not greatly affect the response. However, the response is complex and interpretation ambiguous if both transmitter electrodes are located directly over a body. Boundaries of shallow bodies are much better resolved than those of deep bodies. Conductive bodies produce false polarization highs that can confuse interpretation. It is difficult to distinguish the effects of depth and resistivity contrast, and, as with all electrical methods, depth extent is difficult to resolve. Interactive interpretation of bipole-dipole field results from a geothermal prospect in New Mexico illustrates the value of the 3D modeling technique.
Hohmann, G.W.; Jiracek, G.R.
Poster: performance modeling and computational quality of service (CQoS) in synergia2 accelerator simulations
High-precision accelerator modeling is essential for particle accelerator design and optimization. However, this modeling presents a significant computational challenge. We discuss performance modeling of and computational quality of service (CQoS) results ... Keywords: accelerator simulation, computational quality of service, performance modeling, synergia
Steve Goldhaber; Stefan Muszala; Nanbor Wang; James F. Amundson; Eric G. Stern; Boyana Norris; Daihee Kim
Developments in computation, modeling and experimentation: Impacts on R D
The original objective was to document the feasibility of the coordinated research program sponsored by ECUT called Materials-by-Design (MBD).'' The MBD program funds research to develop hierarchical models to predict materials' performance based on microstructural information. This paper was specifically prepared for this meeting to help technical staff and their managers justify and plan for an advanced computer infrastructure within their companies. In order to do this, several additional objectives for this paper are (1) to foster an appreciation of the dramatic increase in computational power that have occurred over the last forty years, (2) to encourage better utilization of supercomputing in current scientific research by identifying current issues and opportunities, and (3) to promote anticipation and enthusiasm for the dramatic changes supercomputers currently being developed will offer scientists in the near future.
Young, J.K.
The new computer program for three dimensional relativistic hydrodynamical model
An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.
Daniel Kikola; Wiktor Peryt; Yuri M. Sinyukov; Marcin Slodkowski; Marek Szuba
Foam computer model helps in analysis of underbalanced drilling
A new mechanistic model attempts to overcome many of the problems associated with existing foam flow analyses. The model calculates varying Fanning friction factors, rather than assumed constant factors, along the flow path. Foam generated by mixing gas and liquid for underbalanced drilling has unique rheological characteristics, making it very difficult to accurately predict the pressure profile. A user-friendly personal-computer program was developed to solve the mechanical energy balance equation for compressible foam flow. The program takes into account influxes of gas, liquid, and oil from formations. The pressure profile, foam quality, density, and cuttings transport are predicted by the model. A sensitivity analysis window allows the user to quickly optimize the hydraulics program by selecting the best combination of injection pressure, back pressure, and gas/liquid injection rates. This new model handles inclined and horizontal well bores and provides handy engineering and design tools for underbalanced drilling, well bore cleanout, and other foam operations. The paper describes rheological models, foam flow equations, equations of state, mechanical energy equations, pressure drop across nozzles, influx modeling, program operation, comparison to other models, to lab data, and to field data, and results.
Liu, G.; Medley, G.H. Jr. [Maurer Engineering Inc., Houston, TX (United States)
Three-dimensional computer modeling of hydrogen injection and combustion
The hydrodynamics of hydrogen gas injection into a fixed-volume combustion chamber is analyzed and simulated using KIVA-3, a three-dimensional, reactive flow computer code. Comparisons of the simulation results are made to data obtained at the Combustion Research Facility at Sandia National Laboratory-California (SNL-CA). Simulation of the gas injection problem is found to be of comparable difficulty as the liquid fuel injection in diesel engines. The primary challenge is the large change of length scale from the flow of gas in the orifice to the penetration in the combustion chamber. In the current experiments, the change of length scale is about 4,000. A reduction of the full problem is developed that reduces the change in length scale in the simulation to about 400, with a comparable improvement in computational times. Comparisons of the simulation to the experimental data shows good agreement in the penetration history and pressure rise in the combustion chamber. At late times the comparison is sensitive to the method of determination of the penetration in the simulations. In a comparison of the combustion modeling of methane and hydrogen, hydrogen combustion is more difficult to model, and currently available kinetic models fail to predict the observed autoignition delay at these conditions.
Johnson, N.L.; Amsden, A.A. [Los Alamos National Lab., NM (United States). Theoretical Division; Naber, J.D.; Siebers, D.L. [Sandia National Lab., Livermore, CA (United States)
Computing Models of CDF and D0 in Run II
The next collider run of the Fermilab Tevatron, Run II, is scheduled for autumn of 1999. Both experiments, the Collider Detector at Fermilab (CDF) and the D0 experiment are being modified to cope with the higher luminosity and shorter bunch spacing of the Tevatron. New detector components, higher event complexity, and an increased data volume require changes from the data acquisition systems up to the analysis systems. In this paper we present a summary of the computing models of the two experiments for Run II.
Lammel, S.
Computer Modeling Illuminates Degradation Pathways of Cations in Alkaline Membrane Fuel Cells (Fact Sheet)
Cation degradation insights obtained by computational modeling could result in better performance and longer lifetime for alkaline membrane fuel cells.
Computational Fluid Dynamics Modeling of Atmospheric Flow Applied to Wind Energy Research.
??High resolution atmospheric flow modeling using computational fluid dynamics (CFD) has many applications in the wind energy industry. A well designed model can accurately calculate� (more)
Russell, Alan
from rain, solar radiation and other crucial weather events on an hourly basis. Both vapor and liquid and uses weather data files from all over the country. The software includes analysis to predict mold. Dr of multi- layer building walls exposed to natural weather. The WUFI series models can handle contributions
Oak Ridge National Laboratory
Ubiquitous Computing Acceptance Model: end user concern about security, privacy and risk
This study integrates cognitive and affective attitudes as the primary factors of influence to formulate a Ubiquitous Computing Acceptance Model (UCAM), which is intended to predict whether potential users will accept ubiquitous computing (u-computing). ... Keywords: UCAM, behavioural intention, mobile communications, perceived ease of use, perceived risk, pervasive computing, privacy, security, trust, ubiquitous city, ubiquitous computing acceptance model, ubiquitous u-city, usefulness, user attitudes, user intentions
Dong-Hee Shin
Computational fluid dynamic modeling of fluidized-bed polymerization reactors
Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.
Rokkam, Ram [Ames Laboratory
The objective of this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed and is appended in this report. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The details are presented in the attached paper titled ''CFD Simulation of Flow and Turbulence in a Slurry Bubble Column''. This phase of the work is in press in a referred journal (AIChE Journal, 2002) and was presented at the Fourth International Conference on Multiphase Flow (ICMF 2001) in New Orleans, May 27-June 1, 2001 (Paper No. 909). The computed time averaged particle velocities and concentrations agree with Particle Image Velocimetry (PIV) measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. To better understand turbulence we studied fluidization in a liquid-solid bed. This work was also presented at the Fourth International Conference on Multiphase Flow (ICMF 2001, Paper No. 910). To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. This report summarizes the measurements and simulations completed so far. This work will continue under the sponsorship of the National Science Foundation and Dow Corning Corporation. This phase of the work is part of the DOE/Industry/University Multiphase Fluid Dynamics Research Consortium. Optimization of the LaPorte pilot plant reactor was attempted by rearranging the heat exchangers. The paper accepted for presentation at the Sixth World Congress of Chemical Engineering, Melbourne, Australia, September 23-27, 2001 is a part of this report.
Paul C.K. Lam; Isaac K. Gamwo; Dimitri Gidaspow
HEAP: heat energy analysis program. A computer model simulating solar receivers
Thermal design of solar receivers is commonly accomplished via approximate models, where the receiver is treated as an isothermal box with lumped quantities of heat losses to the surroundings by radiation, conduction and convection. These approximate models, though adequate for preliminary design purposes, are not detailed enough to distinguish between different receiver designs, or to predict transient performance under variable solar flux, ambient temperatures, etc. A computer code has been written for this purpose and is given the name HEAP, an acronym for Heat Energy Analysis Program. HEAP has a basic structure that fits a general heat transfer problem, but with specific features that are custom-made for solar receivers. The code is written in MBASIC computer language. This document explains the detailed methodology followed in solving the heat transfer problem, and includes a program flow chart, an explanation of input and output tables, and an example of the simulation of a cavity-type solar receiver.
Lansing, F.L.
Review: Application of computational fluid dynamics for modeling and designing photobioreactors for microalgae production: A review
The past decade has seen a rapid increase of numerical simulation studies on photobioreactors (PBRs). Developments in computational fluid dynamics (CFD) and the availability of more powerful computers have paved the way for the modeling and designing ... Keywords: Computational fluid dynamics (CFD), Computer simulation, Microalgae, Photobioreactors
J. P. Bitog; I. -B. Lee; C. -G. Lee; K. -S. Kim; H. -S. Hwang; S. -W. Hong; I. -H. Seo; K. -S. Kwon; E. Mostafa
Using a Phenomenological Computer Model to Investigate Advanced Combustion Trajectories in a CIDI Engine
This paper summarizes results from simulations of conventional, high-dilution, and high-efficiency clean combustion in a diesel engine based on a two-zone phenomenological model. The two-zone combustion model is derived from a previously published multi-zone model, but it has been further simplified to increase computational speed by a factor of over 100. The results demonstrate that this simplified model is still able to track key aspects of the combustion trajectory responsible for NOx and soot production. In particular, the two-zone model in combination with highly simplified global kinetics correctly predicts the importance of including oxygen mass fraction (in addition to equivalence ratio and temperature) in lowering emissions from high-efficiency clean combustion. The methodology also provides a convenient framework for extracting information directly from in-cylinder pressure measurements. This feature is likely to be useful for on-board combustion diagnostics and controls. Because of the possibility for simulating large numbers of engine cycles in a short time, models of this type can provide insight into multi-cycle and transient combustion behavior not readily accessible to more computationally intensive models. Also the representation of the combustion trajectory in 3D space corresponding to equivalence ratio, flame temperature, and oxygen fraction provides new insight into optimal combustion management.
Gao, Zhiming [ORNL; Wagner, Robert M [ORNL; Sluder, Scott [ORNL; Daw, C Stuart [ORNL; Green Jr, Johney Boyd [ORNL
Computation Modeling and Assessment of Nanocoatings for Ultra Supercritical Boilers
Forced outages and boiler unavailability of coal-fired fossil plants is most often caused by fire-side corrosion of boiler waterwalls and tubing. Reliable coatings are required for Ultrasupercritical (USC) application to mitigate corrosion since these boilers will operate at a much higher temperatures and pressures than in supercritical (565 C {at} 24 MPa) boilers. Computational modeling efforts have been undertaken to design and assess potential Fe-Cr-Ni-Al systems to produce stable nanocrystalline coatings that form a protective, continuous scale of either Al{sub 2}O{sub 3} or Cr{sub 2}O{sub 3}. The computational modeling results identified a new series of Fe-25Cr-40Ni with or without 10 wt.% Al nanocrystalline coatings that maintain long-term stability by forming a diffusion barrier layer at the coating/substrate interface. The computational modeling predictions of microstructure, formation of continuous Al{sub 2}O{sub 3} scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. Advanced coatings, such as MCrAl (where M is Fe, Ni, or Co) nanocrystalline coatings, have been processed using different magnetron sputtering deposition techniques. Several coating trials were performed and among the processing methods evaluated, the DC pulsed magnetron sputtering technique produced the best quality coating with a minimum number of shallow defects and the results of multiple deposition trials showed that the process is repeatable. scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. The cyclic oxidation test results revealed that the nanocrystalline coatings offer better oxidation resistance, in terms of weight loss, localized oxidation, and formation of mixed oxides in the Al{sub 2}O{sub 3} scale, than widely used MCrAlY coatings. However, the ultra-fine grain structure in these coatings, consistent with the computational model predictions, resulted in accelerated Al diffusion from the coating into the substrate. An effective diffusion barrier interlayer coating was developed to prevent inward Al diffusion. The fire-side corrosion test results showed that the nanocrystalline coatings with a minimum number of defects have a great potential in providing corrosion protection. The coating tested in the most aggressive environment showed no evidence of coating spallation and/or corrosion attack after 1050 hours exposure. In contrast, evidence of coating spallation in isolated areas and corrosion attack of the base metal in the spalled areas were observed after 500 hours. These contrasting results after 500 and 1050 hours exposure suggest that the premature coating spallation in isolated areas may be related to the variation of defects in the coating between the samples. It is suspected that the cauliflower-type defects in the coating were presumably responsible for coating spallation in isolated areas. Thus, a defect free good quality coating is the key for the long-term durability of nanocrystalline coatings in corrosive environments. Thus, additional process optimization work is required to produce defect-free coatings prior to development of a coating application method for production parts.
J. Shingledecker; D. Gandy; N. Cheruvu; R. Wei; K. Chan
Soft computing approach for modeling power plant with a once-through boiler
In this paper, a soft computing approach is presented for modeling electrical power generating plants in order to characterize the essential dynamic behavior of the plant subsystems. The structure of the soft computing method consists of fuzzy logic, ... Keywords: Experimental data, Fuzzy modeling, Genetic algorithm, Neural network, Once-through boiler, Power plant, Soft computing
Ali Ghaffari; Ali Chaibakhsh; Caro Lucas
Molecular Computation Models in ACL2: a Simulation of Lipton's Experiment Solving SAT.
Molecular Computation Models in ACL2: a Simulation of Lipton's Experiment Solving SAT. F.J. Mart Abstract In this paper we present an ACL2 formalization of a molecular computing model: Adle- man to build a prototype of a molecular computer. In 1995, R.J. Lipton [7] solved an instance
Alonso, José A.
Probabilistic versus possibilistic risk assessment models for optimal service level agreements in grid computing
We present a probabilistic and a possibilistic model for assessing the risk of a service level agreement for a computing task in a cluster/grid environment. These models can also be applied to cloud computing. Using the predictive probabilistic approach ... Keywords: Grid and cloud computing, Predictive possibilities, Predictive probabilities, Service level agreement (SLA)
Christer Carlsson; Robert Full�r
A Computational Model of Cellular Response to Modulated Radiation Fields
Purpose: To develop a model to describe the response of cell populations to spatially modulated radiation exposures of relevance to advanced radiotherapies. Materials and Methods: A Monte Carlo model of cellular radiation response was developed. This model incorporated damage from both direct radiation and intercellular communication including bystander signaling. The predictions of this model were compared to previously measured survival curves for a normal human fibroblast line (AGO1522) and prostate tumor cells (DU145) exposed to spatially modulated fields. Results: The model was found to be able to accurately reproduce cell survival both in populations which were directly exposed to radiation and those which were outside the primary treatment field. The model predicts that the bystander effect makes a significant contribution to cell killing even in uniformly irradiated cells. The bystander effect contribution varies strongly with dose, falling from a high of 80% at low doses to 25% and 50% at 4 Gy for AGO1522 and DU145 cells, respectively. This was verified using the inducible nitric oxide synthase inhibitor aminoguanidine to inhibit the bystander effect in cells exposed to different doses, which showed significantly larger reductions in cell killing at lower doses. Conclusions: The model presented in this work accurately reproduces cell survival following modulated radiation exposures, both in and out of the primary treatment field, by incorporating a bystander component. In addition, the model suggests that the bystander effect is responsible for a significant portion of cell killing in uniformly irradiated cells, 50% and 70% at doses of 2 Gy in AGO1522 and DU145 cells, respectively. This description is a significant departure from accepted radiobiological models and may have a significant impact on optimization of treatment planning approaches if proven to be applicable in vivo.
McMahon, Stephen J., E-mail: email@example.com [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Butterworth, Karl T. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)] [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); McGarry, Conor K. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom) [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Trainor, Colman [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)] [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); O'Sullivan, Joe M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom) [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Hounsell, Alan R. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom) [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)] [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)
CAPE-OPEN compliant stochastic modeling and reduced-order model computation capability for APECS system
APECS (Advanced Process Engineering Co-Simulator) is an integrated software suite that combines the power of process simulation with high-fidelity, computational fluid dynamics (CFD) for improved design, analysis, and optimization of process engineering systems. The APECS system uses commercial process simulation (e.g., Aspen Plus) and CFD (e.g., FLUENT) software integrated with the process-industry standard CAPE-OPEN (CO) interfaces. This breakthrough capability allows engineers to better understand and optimize the fluid mechanics that drive overall power plant performance and efficiency. The focus of this paper is the CAPE-OPEN complaint stochastic modeling and reduced order model computational capability around the APECS system. The usefulness of capabilities is illustrated with coal fired, gasification based, FutureGen power plant simulation. These capabilities are used to generate efficient reduced order models and optimizing model complexities.
Diwekar, Urmila (Vishwamitra Research Institute, Clarendon Hills, IL); Shastri, Yogendra (Vishwamitra Research Institute Clarendon Hills, IL); Subrmanyan, Karthik (Vishwamitra Research Institute, Clarendon Hills, IL); Zitney, S.E.
How to choose the simulation model for computer experiments: a local approach
In many scientific areas, non-stochastic simulation models such as finite element simulations replace real experiments. A common approach is to fit a meta-model, for example a Gaussian process model, a radial basis function interpolation, or a kernel ... Keywords: Gaussian process model, computer code validation, computer experiment, kernel interpolation, sheet metal forming
Thomas M�hlenst�dt; Marco G�sling; Sonja Kuhnt
Model discovery for energy-aware computing systems: An experimental evaluation
We present a model-discovery methodology for energy-aware computing systems that achieves high prediction accuracy. Model discovery, or system identification, is a critical first step in designing advanced controllers that can dynamically manage the ... Keywords: SISO model, energy aware computing system, model discovery methodology, energy performance trade off, multiple inputs multiple outputs model, single input single output model, representative server workload, MIMO model
Zhichao Li; R. Grosu; K. Muppalla; S. A. Smolka; S. D. Stoller; E. Zadok
The objective of this study is to develop a predictive experimentally verified computational fluid dynamic (CFD) three phase model. It predicts the gas, liquid and solid hold-ups (volume fractions) and flow patterns in the industrially important bubble-coalesced (churn-turbulent) regime. The input into the model can be either particulate viscosities as measured with a Brookfield viscometer or effective restitution coefficient for particles. A combination of x-ray and {gamma}-ray densitometers was used to measure solid and liquid volume fractions. There is a fair agreement between the theory and the experiment. A CCD camera was used to measure instantaneous particle velocities. There is a good agreement between the computed time average velocities and the measurements. There is an excellent agreement between the viscosity of 800 {micro}m glass beads obtained from measurement of granular temperature (random kinetic energy of particles) and the measurement using a Brookfield viscometer. A relation between particle Reynolds stresses and granular temperature was found for developed flow. Such measurement and computations gave a restitution coefficient for a methanol catalyst to be about 0.9. A transient, two-dimensional hydrodynamic model for production of methanol from syn-gas in an Air Products/DOE LaPorte slurry bubble column reactor was developed. The model predicts downflow of catalyst at the walls and oscillatory particle and gas flow at the center, with a frequency of about 0.7 Hertz. The computed temperature variation in the rector with heat exchangers was only about 5 K, indicating good thermal management. The computed slurry height, the gas holdup and the rate of methanol production agree with LaPorte's reported data. Unlike the previous models in the literature, this model computes the gas and the particle holdups and the particle rheology. The only adjustable parameter in the model is the effective particle restitution coefficient.
Reduced-order, trajectory piecewise-linear models for nonlinear computational fluid dynamics
Computational fluid dynamics (CFD) is now widely used throughout the fluid dynamics community and yields accurate models for problems of interest. However, due to its high computational cost, CFD is limited for some ...
Gratton, David, 1979-
HIV virus spread and evolution studied through computer modeling
differential equations on the computer; this is done for computational speed, because an agent-based component is much more demanding. Once a person is infected, heshe becomes an...
Computer system performance problem detection using time series models
Computer systems require monitoring to detect performance anomalies such as runaway processes, but problem detection and diagnosis is a complex task requiring skilled attention. Although human attention was never ideal for this task, as networks of computers ...
Peter Hoogenboom; Jay Lepreau
A Model for Fast Analog Computation Based on Unreliable Synapses
We investigate through theoretical analysis and computer simulations the consequences of unreliable synapses for fast analog computations in networks of spiking neurons, with analog variables encoded by the current firing activities of pools of spiking ...
Wolfgang Maass; Thomas Natschl�ger
Integrating �depth first� and �breadth first� models of computing curricula
Traditional undergraduate Computer Science curricula have been increasingly challenged on a host of grounds: undergraduate computing education is attracting fewer majors, is not producing graduates who satisfy the needs of either graduate programs or ...
Russell L. Shackelford; Richard J. LeBlanc
ANEMIC: automatic interface enabler for model integrated computing
A domain-specific language provides domain experts with a familiar abstraction for creating computer programs. As more and more domains embrace computers, programmers are tapping into this power by creating their own languages fitting the particular ...
Steve Nordstrom; Shweta Shetty; Kumar Gaurav Chhokra; Jonathan Sprinkle; Brandon Eames; Akos Ledeczi
Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model
Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.
Sharma, Chandan; Raustad, Richard
The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in very high temperature reactors (VHTRs). Phenomena Identification and Ranking Studies to date have ranked an air ingress event, following on the heels of a VHTR depressurization, as important with regard to core safety. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority. Following a loss of coolant and system depressurization incident, air will enter the core of the High Temperature Gas Cooled Reactor through the break, possibly causing oxidation of the in-the core and reflector graphite structure. Simple core and plant models indicate that, under certain circumstances, the oxidation may proceed at an elevated rate with additional heat generated from the oxidation reaction itself. Under postulated conditions of fluid flow and temperature, excessive degradation of the lower plenum graphite can lead to a loss of structural support. Excessive oxidation of core graphite can also lead to the release of fission products into the confinement, which could be detrimental to a reactor safety. Computational fluid dynamic model developed in this study will improve our understanding of this phenomenon. This paper presents two-dimensional and three-dimensional CFD results for the quantitative assessment of the air ingress phenomena. A portion of results of the density-driven stratified flow in the inlet pipe will be compared with results of the experimental results.
Chang H. Oh; Eung S. Kim; Richard Schultz; Hans Gougar; David Petti; Hyung S. Kang
Computing Computing and Storage Requirements Computing and Storage Requirements for FES J. Candy General Atomics, San Diego, CA Presented at DOE Technical Program Review Hilton Washington DC/Rockville Rockville, MD 19-20 March 2013 2 Computing and Storage Requirements Drift waves and tokamak plasma turbulence Role in the context of fusion research * Plasma performance: In tokamak plasmas, performance is limited by turbulent radial transport of both energy and particles. * Gradient-driven: This turbulent transport is caused by drift-wave instabilities, driven by free energy in plasma temperature and density gradients. * Unavoidable: These instabilities will persist in a reactor. * Various types (asymptotic theory): ITG, TIM, TEM, ETG . . . + Electromagnetic variants (AITG, etc). 3 Computing and Storage Requirements Fokker-Planck Theory of Plasma Transport Basic equation still
Integrated Computational Materials Engineering: Digital Resource ...
Feb 15, 2007 ... For other multi-scale computational research project descriptions including: " Computational Modeling of Fatigue, Fracture, and Ductile Failure�...
SCRAM: a fast computational model for the optical performance of point fucus solar central receiver systems
Because of the complexities of heliostat shadowing and blocking calculations, computational models for the optical performance of point focus central receiver (PFCR) systems tend to be too slow for many important applications, such as optimization studies based on performance with realistic weather data. In this paper, a mathematical approximation procedure, designated Sandia Central Receiver Approximation Model (SCRAM) will be described. Rather than simulating the system components from first principles, it relies on data generated by the DELSOL code of Dellin and Fish for the optical performance of PFCR systems, and abstracts a mathematical model using a stepwise regression procedure. The result is a computational procedure which allows the user to define the heliostat field boundaries and tower height arbitrarily, generating a model for optical field performance, including shadowing, blocking, cosine, losses, and atmospheric attenuation, and which requires only a polynomial evaluation for each set of sun angles. A comparison with DELSOL for three different fields on three representative days indicates that the rms error of the approximation is 1-3% and that the new code is 1,000-3,000 times as fast as DELSOL. It is also shown that one reason that the accuracy in field performance predictions is higher than that of the generting function for the model is that much of the error in the generating function is due to an oscillatory behavior associated with a moire pattern in the optical response of the heiostat field.
Bergeron, K. D.; Chiang, C. J.
Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers
Forced outages and boiler unavailability in conventional coal-fired fossil power plants is most often caused by fireside corrosion of boiler waterwalls. Industry-wide, the rate of wall thickness corrosion wastage of fireside waterwalls in fossil-fired boilers has been of concern for many years. It is significant that the introduction of nitrogen oxide (NOx) emission controls with staged burners systems has increased reported waterwall wastage rates to as much as 120 mils (3 mm) per year. Moreover, the reducing environment produced by the low-NOx combustion process is the primary cause of accelerated corrosion rates of waterwall tubes made of carbon and low alloy steels. Improved coatings, such as the MCrAl nanocoatings evaluated here (where M is Fe, Ni, and Co), are needed to reduce/eliminate waterwall damage in subcritical, supercritical, and ultra-supercritical (USC) boilers. The first two tasks of this six-task project-jointly sponsored by EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)-have focused on computational modeling of an advanced MCrAl nanocoating system and evaluation of two nanocrystalline (iron and nickel base) coatings, which will significantly improve the corrosion and erosion performance of tubing used in USC boilers. The computational model results showed that about 40 wt.% is required in Fe based nanocrystalline coatings for long-term durability, leading to a coating composition of Fe-25Cr-40Ni-10 wt.% Al. In addition, the long term thermal exposure test results further showed accelerated inward diffusion of Al from the nanocrystalline coatings into the substrate. In order to enhance the durability of these coatings, it is necessary to develop a diffusion barrier interlayer coating such TiN and/or AlN. The third task 'Process Advanced MCrAl Nanocoating Systems' of the six-task project jointly sponsored by the Electric Power Research Institute, EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)- has focused on processing of advanced nanocrystalline coating systems and development of diffusion barrier interlayer coatings. Among the diffusion interlayer coatings evaluated, the TiN interlayer coating was found to be the optimum one. This report describes the research conducted under the Task 3 workscope.
David W. Gandy; John P. Shingledecker
A Comparison of Methods for Computing the Sigma-Coordinate Pressure Gradient Force for Flow over Sloped Terrain in a Hybrid Theta-Sigma Model
Five methods for computing the pressure gradient force within a sigma domain of a hybrid model are compared for flow over a steeply sloped terrain. The comparison includes pressure gradient calculations determined from a direct transformation to ...
Donald R. Johnson; Louis W. Uccellini
Mathematical models and algorithms for the computer program 'WOLF'
The computer program FLOW finds the nonrelativistic self- consistent set of two-dimensional ion trajectories and electric fields (including space charges from ions and electrons) for a given set of initial and boundary conditions for the particles and fields. The combination of FLOW with the optimization code PISA gives the program WOLF, which finds the shape of the emitter which is consistent with the plasma forming it, and in addition varies physical characteristics such as electrode position, shapes, and potentials so that some performance characteristics are optimized. The motivation for developing these programs was the desire to design optimum ion source extractor/accelerator systems in a systematic fashion. The purpose of this report is to explain and derive the mathematical models and algorithms which approximate the real physical processes. It serves primarily to document the computer programs. 10 figures. (RWR)
Halbach, K.
A comparative study of model selection criteria for computer vision applications
During last three decades many model selection techniques have been developed, many of those have also been employed in computer vision applications. Interestingly, most of those criteria are based upon assumptions that are rarely realised in practical ... Keywords: Model selection, Model-based computer vision, Motion segmentation, Range segmentation
Niloofar Gheissari; Alireza Bab-Hadiashar
Investigating the properties of adaptation in a computational model of the olfactory sensory neuron
We developed a detailed computational model of an olfactory sensory neuron to investigate the functional properties of the sensory adaptation in the peripheral olfactory system. The model consists of a system of first-order differential equations that ... Keywords: Adaptation, Computational model, Olfactory code, Olfactory epithelium, Olfactory sensory neuron, Sniffing
Fabio M. Simoes de Souza; Gabriela Antunes
Computational modeling and design of actively-cooled microvascular materials Soheil Soghrati a,b
were used for the calibration and validation of the 2D IGFEM model. Water was used as the coolantComputational modeling and design of actively-cooled microvascular materials Soheil Soghrati a a c t The computational modeling and design of an actively-cooled microvascular fin specimen
Braun, Paul
Orientational relaxation in a dispersive dynamic medium : Generalization of the Kubo-Ivanov-Anderson jump diffusion model to include fractional environmental dynamics
Ivanov-Anderson (IA) model (and an earlier treatment by Kubo) envisages a decay of the orientational correlation by random but large amplitude molecular jumps, as opposed to infinitesimal small jumps assumed in Brownian diffusion. Recent computer simulation studies on water and supercooled liquids have shown that large amplitude motions may indeed be more of a rule than exception. Existing theoretical studies on jump diffusion mostly assume an exponential (Poissonian) waiting time distribution for jumps, thereby again leading to an exponential decay. Here we extend the existing formalism of Ivanov and Anderson to include an algebraic waiting time distribution between two jumps. As a result, the first and second rank orientational time correlation functions show the same long time power law, but their short time decay behavior is quite different. The predicted Cole-Cole plot of dielectric relaxation reproduces various features of non-Debye behaviour observed experimentally. We also developed a theory where both unrestricted small jumps and large angular jumps coexist simultaneously. The small jumps are shown to have a large effect on the long time decay, particularly in mitigating the effects of algebraic waiting time distribution, and in giving rise to an exponential-like decay, with a time constant, surprisingly, less than the time constant that arises from small amplitude decay alone.
K. Seki; B. Bagchi; M. Tachiya
Computer modeling of organic aerogels: Final report of 93-SR-062
Goal of the work was to develop computer models of organic aerogel structures, and to study transport process within these materials. During the course of the research understanding of the structure of all aerogels including acid and neutral-catalyzed silica aerogel was developed. The modeling of transport focused on fluid flow in aerogels. We successfully modified a novel state-of-the-art lattice Boltzmann code to simulate flow at low Knudsen number, and developed a simple molecular dynamics code for gas flow at extremely high Knudsen number (low density). These flow-modeling techniques can be used to study aerogel applications for technology transfer; in addition, these techniques can be used to study flow through other porous materials.
Chandler, E.A.; Calef, D.; Ladd, A.J.C.
Cross-cooled dehumidifier model test results and computer simulations
Research on the development of a solar operated cross-cooled desiccant cooling system is described. A 15 cm x 15 cm x 15 cm (6'' x 6'' x 6'') cross-cooled silica gel desiccant dehumidifier model was designed, built and tested. The process of producing the silica gel sheets, the design and construction of the unit, the test setup and the test procedures are described in detail. A total of twenty tests were performed to determine the effect of inlet process stream dew point, process stream and cooling stream flowrates and regeneration stream temperature and dew point, on the performance of the unit. The test results show that the unit performance improves with increasing regeneration temperature, process stream flowrate and process air inlet dew point. The unit performance decreases with increase of the regeneration stream dew point. The results clearly show that the process stream inlet dew point is the dominating factor and that the concept of cross-cooling works very well. With moderate cross-cooling, the unit performance can increase over 50%. All tests were simulated by a computer program. The experimental and theoretical results are in very good agreement.
Mei, V.; Lavan, Z.
Modeling-Computer Simulations At U.S. West Region (Williams ...
Search Page Edit History Facebook icon Twitter icon Modeling-Computer Simulations At U.S. West Region (Williams & Deangelo, 2008) Jump to: navigation, search GEOTHERMAL...
Modeling-Computer Simulations At U.S. West Region (Sabin, Et...
Search Page Edit History Facebook icon Twitter icon Modeling-Computer Simulations At U.S. West Region (Sabin, Et Al., 2004) Jump to: navigation, search GEOTHERMAL...
Computer model of a kidney being cooled by ice slurry (Quicktime...
> Videos Detection & Diagnostic Systems: Computer model of a kidney being cooled by ice slurry Quicktime format Quicktime Format - Mid Bandwidth | Size: 1.12 MB | Bit Rate:...
Mathematical modelling, analysis and computation of some complex and nonlinear flow problems.
???This thesis consists of two parts: (I) modelling, analysis and computation of sweat transport in textile media; (II) unconditional convergence and optimal error analysis of� (more)
Li, Buyang (???)
Computation of Grid-Point Values of the Wind Components in Spectral Models
This note presents a method for computing the grid point values of the wind components in spectral models, which is much simpler than the methods generally used.
Michel Rochas
final report for Center for Programming Models for Scalable Parallel Computing
This is the final report of the work on parallel programming patterns that was part of the Center for Programming Models for Scalable Parallel Computing
Johnson, Ralph E.
New Set of Computational Tools and Models Expected to Help Enable...
Tools and Models Expected to Help Enable Rapid Development and Deployment of Carbon Capture Technologies Washington, D.C. - An eagerly anticipated suite of 21 computational...
Building an advanced climate model: Program plan for the CHAMMP (Computer Hardware, Advanced Mathematics, and Model Physics) Climate Modeling Program
The issue of global warming and related climatic changes from increasing concentrations of greenhouse gases in the atmosphere has received prominent attention during the past few years. The Computer Hardware, Advanced Mathematics, and Model Physics (CHAMMP) Climate Modeling Program is designed to contribute directly to this rapid improvement. The goal of the CHAMMP Climate Modeling Program is to develop, verify, and apply a new generation of climate models within a coordinated framework that incorporates the best available scientific and numerical approaches to represent physical, biogeochemical, and ecological processes, that fully utilizes the hardware and software capabilities of new computer architectures, that probes the limits of climate predictability, and finally that can be used to address the challenging problem of understanding the greenhouse climate issue through the ability of the models to simulate time-dependent climatic changes over extended times and with regional resolution.
Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett,
Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown References J. W. Pritchett (2004) Finding Hidden Geothermal Resources In The Basin And Range Using Electrical Survey Techniques- A Computational Feasibility Study Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Pritchett,_2004)&oldid=401423"
An Evaluation of Precipitation Forecasts from Operational Models and Reanalyses Including Precipitation Variations Associated with MJO Activity
In this paper, the results of an examination of precipitation forecasts for 1�30-day leads from global models run at the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) ...
John E. Janowiak; Peter Bauer; Wanqiu Wang; Phillip A. Arkin; Jon Gottschalck
Atmospheric Turbulence above Coastal Waters: Determination of Stability Classes and a Simple Model for Offshore Flow Including Advection and Dissipation
Atmospheric turbulence intensities and timescales have been measured for one year and modeled in a shoreline environment. Measurements were carded out at two sites on both sides of the shoreline, about 10 km from the beach. The frequency ...
Hans J. Erbrink; Rudy D. A. Scholten
Quantum Computing and Lie Theory Feynman's suggestion that the only effective way to model quantum phe-
Quantum Computing and Lie Theory Feynman's suggestion that the only effective way to model quantum phe- nomena on a computer would be to build a computer that made use of quantum mechanics was one of the cornerstones of the birth of quantum com- puting. In his later years he studied both classical and quantum
D'Agnolo, Andrea
Computational Mechanistic Studies of Acid-Catalyzed Lignin Model Dimers for Lignin Depolymerization
Lignin is a heterogeneous alkyl-aromatic polymer that constitutes up to 30% of plant cell walls, and is used for water transport, structure, and defense. The highly irregular and heterogeneous structure of lignin presents a major obstacle in the development of strategies for its deconstruction and upgrading. Here we present mechanistic studies of the acid-catalyzed cleavage of lignin aryl-ether linkages, combining both experimental studies and quantum chemical calculations. Quantum mechanical calculations provide a detailed interpretation of reaction mechanisms including possible intermediates and transition states. Solvent effects on the hydrolysis reactions were incorporated through the use of a conductor-like polarizable continuum model (CPCM) and with cluster models including explicit water molecules in the first solvation shell. Reaction pathways were computed for four lignin model dimers including 2-phenoxy-phenylethanol (PPE), 1-(para-hydroxyphenyl)-2-phenoxy-ethanol (HPPE), 2-phenoxy-phenyl-1,3-propanediol (PPPD), and 1-(para-hydroxyphenyl)-2-phenoxy-1,3-propanediol (HPPPD). Lignin model dimers with a para-hydroxyphenyl ether (HPPE and HPPPD) show substantial differences in reactivity relative to the phenyl ether compound (PPE and PPPD) which have been clarified theoretically and experimentally. The significance of these results for acid deconstruction of lignin in plant cell walls will be discussed.
Kim, S.; Sturgeon, M. R.; Chmely, S. C.; Paton, R. S.; Beckham, G. T.
A situation-aware computational trust model for selecting partners
Trust estimation is a fundamental process in several multiagent systems domains, from social networks to electronic business scenarios. However, the majority of current computational trust systems is still too simplistic and is not situation-aware, jeopardizing ... Keywords: computational trust systems, dynamics of trust, multi-agent systems, situationaware trust
Joana Urbano; Ana Paula Rocha; Eug�nio Oliveira
COMFAR III: Computer Model for Feasibility Analysis and Reporting | Open
COMFAR III: Computer Model for Feasibility Analysis and Reporting COMFAR III: Computer Model for Feasibility Analysis and Reporting Jump to: navigation, search Tool Summary Name: COMFAR III: Computer Model for Feasibility Analysis and Reporting Agency/Company /Organization: United Nations Industrial Development Organization Focus Area: Industry Resource Type: Software/modeling tools User Interface: Desktop Application Website: www.unido.org/index.php?id=o3470 Language: "Arabic, Chinese, English, French, German, Japanese, Portuguese, Russian, Spanish; Castilian" is not in the list of possible values (Abkhazian, Achinese, Acoli, Adangme, Adyghe; Adygei, Afar, Afrihili, Afrikaans, Afro-Asiatic languages, Ainu, Akan, Akkadian, Albanian, Aleut, Algonquian languages, Altaic languages, Amharic, Angika, Apache languages, Arabic, Aragonese, Arapaho, Arawak, Armenian, Aromanian; Arumanian; Macedo-Romanian, Artificial languages, Assamese, Asturian; Bable; Leonese; Asturleonese, Athapascan languages, Australian languages, Austronesian languages, Avaric, Avestan, Awadhi, Aymara, Azerbaijani, Balinese, Baltic languages, Baluchi, Bambara, Bamileke languages, Banda languages, Bantu (Other), Basa, Bashkir, Basque, Batak languages, Beja; Bedawiyet, Belarusian, Bemba, Bengali, Berber languages, Bhojpuri, Bihari languages, Bikol, Bini; Edo, Bislama, Blin; Bilin, Blissymbols; Blissymbolics; Bliss, Bosnian, Braj, Breton, Buginese, Bulgarian, Buriat, Burmese, Caddo, Catalan; Valencian, Caucasian languages, Cebuano, Celtic languages, Central American Indian languages, Central Khmer, Chagatai, Chamic languages, Chamorro, Chechen, Cherokee, Cheyenne, Chibcha, Chichewa; Chewa; Nyanja, Chinese, Chinook jargon, Chipewyan; Dene Suline, Choctaw, Chuukese, Chuvash, Classical Newari; Old Newari; Classical Nepal Bhasa, Classical Syriac, Coptic, Cornish, Corsican, Cree, Creek, Creoles and pidgins , Crimean Tatar; Crimean Turkish, Croatian, Cushitic languages, Czech, Dakota, Danish, Dargwa, Delaware, Dinka, Divehi; Dhivehi; Maldivian, Dogri, Dogrib, Dravidian languages, Duala, Dutch; Flemish, Dyula, Dzongkha, Eastern Frisian, Efik, Egyptian (Ancient), Ekajuk, Elamite, English, Erzya, Esperanto, Estonian, Ewe, Ewondo, Fang, Fanti, Faroese, Fijian, Filipino; Pilipino, Finnish, Finno-Ugrian languages, Fon, French, Friulian, Fulah, Ga, Gaelic; Scottish Gaelic, Galibi Carib, Galician, Ganda, Gayo, Gbaya, Geez, Georgian, German, Germanic languages, Gilbertese, Gondi, Gorontalo, Gothic, Grebo, Greek, Modern, Guarani, Gujarati, Gwich'in, Haida, Haitian; Haitian Creole, Hausa, Hawaiian, Hebrew, Herero, Hiligaynon, Himachali languages; Western Pahari languages, Hindi, Hiri Motu, Hittite, Hmong; Mong, Hungarian, Hupa, Iban, Icelandic, Ido, Igbo, Ijo languages, Iloko, Inari Sami, Indic languages, Indo-European languages, Indonesian, Ingush, Interlingue; Occidental, Inuktitut, Inupiaq, Iranian languages, Irish, Iroquoian languages, Italian, Japanese, Javanese, Judeo-Arabic, Judeo-Persian, Kabardian, Kabyle, Kachin; Jingpho, Kalaallisut; Greenlandic, Kalmyk; Oirat, Kamba, Kannada, Kanuri, Kara-Kalpak, Karachay-Balkar, Karelian, Karen languages, Kashmiri, Kashubian, Kawi, Kazakh, Khasi, Khoisan languages, Khotanese; Sakan, Kikuyu; Gikuyu, Kimbundu, Kinyarwanda, Kirghiz; Kyrgyz, Klingon; tlhIngan-Hol, Komi, Kongo, Konkani, Korean, Kosraean, Kpelle, Kru languages, Kuanyama; Kwanyama, Kumyk, Kurdish, Kurukh, Kutenai, Ladino, Lahnda, Lamba, Land Dayak languages, Lao, Latin, Latvian, Lezghian, Limburgan; Limburger; Limburgish, Lingala, Lithuanian, Lojban, Lower Sorbian, Lozi, Luba-Katanga, Luba-Lulua, Luiseno, Lule Sami, Lunda, Luo (Kenya and Tanzania), Lushai, Luxembourgish; Letzeburgesch, Macedonian, Madurese, Magahi, Maithili, Makasar, Malagasy, Malay, Malayalam, Maltese, Manchu, Mandar, Mandingo, Manipuri, Manobo languages, Manx, Maori, Mapudungun; Mapuche, Marathi, Mari, Marshallese, Marwari, Masai, Mayan languages, Mende, Mi'kmaq; Micmac, Minangkabau, Mirandese, Mohawk, Moksha, Mon-Khmer languages, Mongo, Mongolian, Mossi, Multiple languages, Munda languages, N'Ko, Nahuatl languages, Nauru, Navajo; Navaho, Ndebele, North; North Ndebele, Ndebele, South; South Ndebele, Ndonga, Neapolitan, Nepal Bhasa; Newari, Nepali, Nias, Niger-Kordofanian languages, Nilo-Saharan languages, Niuean, North American Indian languages, Northern Frisian, Northern Sami, Norwegian, Nubian languages, Nyamwezi, Nyankole, Nyoro, Nzima, Occitan (post 1500); Provençal, Ojibwa, Oriya, Oromo, Osage, Ossetian; Ossetic, Otomian languages, Pahlavi, Palauan, Pali, Pampanga; Kapampangan, Pangasinan, Panjabi; Punjabi, Papiamento, Papuan languages, Pedi; Sepedi; Northern Sotho, Persian, Philippine languages, Phoenician, Pohnpeian, Polish, Portuguese, Prakrit languages, Pushto; Pashto, Quechua, Rajasthani, Rapanui, Rarotongan; Cook Islands Maori, Romance languages, Romanian; Moldavian; Moldovan, Romansh, Romany, Rundi, Russian, Salishan languages, Samaritan Aramaic, Sami languages, Samoan, Sandawe, Sango, Sanskrit, Santali, Sardinian, Sasak, Scots, Selkup, Semitic languages, Serbian, Serer, Shan, Shona, Sichuan Yi; Nuosu, Sicilian, Sidamo, Sign Languages, Siksika, Sindhi, Sinhala; Sinhalese, Sino-Tibetan languages, Siouan languages, Skolt Sami, Slave (Athapascan), Slavic languages, Slovak, Slovenian, Sogdian, Somali, Songhai languages, Soninke, Sorbian languages, Sotho, Southern, South American Indian (Other), Southern Altai, Southern Sami, Spanish; Castilian, Sranan Tongo, Sukuma, Sumerian, Sundanese, Susu, Swahili, Swati, Swedish, Swiss German; Alemannic; Alsatian, Syriac, Tagalog, Tahitian, Tai languages, Tajik, Tamashek, Tamil, Tatar, Telugu, Tereno, Tetum, Thai, Tibetan, Tigre, Tigrinya, Timne, Tiv, Tlingit, Tok Pisin, Tokelau, Tonga (Nyasa), Tonga (Tonga Islands), Tsimshian, Tsonga, Tswana, Tumbuka, Tupi languages, Turkish, Turkmen, Tuvalu, Tuvinian, Twi, Udmurt, Ugaritic, Uighur; Uyghur, Ukrainian, Umbundu, Uncoded languages, Undetermined, Upper Sorbian, Urdu, Uzbek, Vai, Venda, Vietnamese, Volapük, Votic, Wakashan languages, Walamo, Walloon, Waray, Washo, Welsh, Western Frisian, Wolof, Xhosa, Yakut, Yao, Yapese, Yiddish, Yoruba, Yupik languages, Zande languages, Zapotec, Zaza; Dimili; Dimli; Kirdki; Kirmanjki; Zazaki, Zenaga, Zhuang; Chuang, Zulu, Zuni) for this property.
Computational illumination
The field of computational photography includes computational imaging techniques that enhance or extend the capabilities of digital photography, a combination of computer vision, computer graphics, and applied optics. Computational illumination is an ...
Matthew Turk
Computational Methods for Simulating Quantum Computers
This review gives a survey of numerical algorithms and software to simulate quantum computers.It covers the basic concepts of quantum computation and quantum algorithms and includes a few examples that illustrate the use of simulation software for ideal and physical models of quantum computers.
H. De Raedt; K. Michielsen
Analysis of deformable image registration accuracy using computational modeling
Computer aided modeling of anatomic deformation, allowing various techniques and protocols in radiation therapy to be systematically verified and studied, has become increasingly attractive. In this study the potential issues in deformable image registration (DIR) were analyzed based on two numerical phantoms: One, a synthesized, low intensity gradient prostate image, and the other a lung patient's CT image data set. Each phantom was modeled with region-specific material parameters with its deformation solved using a finite element method. The resultant displacements were used to construct a benchmark to quantify the displacement errors of the Demons and B-Spline-based registrations. The results show that the accuracy of these registration algorithms depends on the chosen parameters, the selection of which is closely associated with the intensity gradients of the underlying images. For the Demons algorithm, both single resolution (SR) and multiresolution (MR) registrations required approximately 300 iterations to reach an accuracy of 1.4 mm mean error in the lung patient's CT image (and 0.7 mm mean error averaged in the lung only). For the low gradient prostate phantom, these algorithms (both SR and MR) required at least 1600 iterations to reduce their mean errors to 2 mm. For the B-Spline algorithms, best performance (mean errors of 1.9 mm for SR and 1.6 mm for MR, respectively) on the low gradient prostate was achieved using five grid nodes in each direction. Adding more grid nodes resulted in larger errors. For the lung patient's CT data set, the B-Spline registrations required ten grid nodes in each direction for highest accuracy (1.4 mm for SR and 1.5 mm for MR). The numbers of iterations or grid nodes required for optimal registrations depended on the intensity gradients of the underlying images. In summary, the performance of the Demons and B-Spline registrations have been quantitatively evaluated using numerical phantoms. The results show that parameter selection for optimal accuracy is closely related to the intensity gradients of the underlying images. Also, the result that the DIR algorithms produce much lower errors in heterogeneous lung regions relative to homogeneous (low intensity gradient) regions, suggests that feature-based evaluation of deformable image registration accuracy must be viewed cautiously.
Zhong Hualiang; Kim, Jinkoo; Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States)
Modeling-Computer Simulations At Raft River Geothermal Area (1977) | Open
Raft River Geothermal Area (1977) Raft River Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Raft River Geothermal Area (1977) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis Simulate reservoir performance Notes Computer models describing both the transient reservoir pressure behavior and the time dependent temperature response of the wells were developed. A horizontal, two-dimensional, finite-difference model for calculating pressure effects was constructed to simulate reservoir performance. Vertical, two-dimensional, finite-difference, axisymmetric models for each
Beyond validation: alternative uses and associated assessments of goodness for computational social models
This discussion challenges classic notions of validation, suggesting that �validity' is not just an attribute of a model. It is a function of the relationship of a particular characteristic of the model (the probability that the model will produce ... Keywords: computational models, social modeling, validation
Jessica Glicken Turnley; Peter A. Chew; Aaron S. Perls
GASFLOW: A Computational Fluid Dynamics Code for Gases, Aerosols, and Combustion, Volume 1: Theory and Computational Model
Los Alamos National Laboratory (LANL) and Forschungszentrum Karlsruhe (FzK) are developing GASFLOW, a three-dimensional (3D) fluid dynamics field code as a best-estimate tool to characterize local phenomena within a flow field. Examples of 3D phenomena include circulation patterns; flow stratification; hydrogen distribution mixing and stratification; combustion and flame propagation; effects of noncondensable gas distribution on local condensation and evaporation; and aerosol entrainment, transport, and deposition. An analysis with GASFLOW will result in a prediction of the gas composition and discrete particle distribution in space and time throughout the facility and the resulting pressure and temperature loadings on the walls and internal structures with or without combustion. A major application of GASFLOW is for predicting the transport, mixing, and combustion of hydrogen and other gases in nuclear reactor containments and other facilities. It has been applied to situations involving transporting and distributing combustible gas mixtures. It has been used to study gas dynamic behavior (1) in low-speed, buoyancy-driven flows, as well as sonic flows or diffusion dominated flows; and (2) during chemically reacting flows, including deflagrations. The effects of controlling such mixtures by safety systems can be analyzed. The code version described in this manual is designated GASFLOW 2.1, which combines previous versions of the United States Nuclear Regulatory Commission code HMS (for Hydrogen Mixing Studies) and the Department of Energy and FzK versions of GASFLOW. The code was written in standard Fortran 90. This manual comprises three volumes. Volume I describes the governing physical equations and computational model. Volume II describes how to use the code to set up a model geometry, specify gas species and material properties, define initial and boundary conditions, and specify different outputs, especially graphical displays. Sample problems are included. Volume III contains some of the assessments performed by LANL and FzK. GASFLOW is under continual development, assessment, and application by LANL and FzK. This manual is considered a living document and will be updated as warranted.
Nichols, B.D.; Mueller, C.; Necker, G.A.; Travis, J.R.; Spore, J.W.; Lam, K.L.; Royl, P.; Redlinger, R.; Wilson, T.L.
Resource allocation in cloud computing: model and algorithm
This paper provides an optimal approach to satisfy cloud user requests and schedule resources within cloud computing environment. The paper exploits the market concept into the interaction among the Software as a Service SaaS services providers, service ...
Chunlin Li; Layuan Li
Cloud computing adoption model for governments and large enterprises
Cloud Computing has held organizations across the globe spell bound with its promise. As it moves from being a buzz word and hype into adoption, organizations are faced with question of how to best adopt cloud. Existing ...
Trivedi, Hrishikesh
Performance of Massively Parallel Computers for Spectral Atmospheric Models
Massively parallel processing (MPP) computer systems use high-speed interconnection networks to link hundreds or thousands of RISC microprocessors. With each microprocessor having a peak performance of 100 or more megaflops per second, there is ...
Ian T. Foster; Brian Toonen; Patrick H. Worley
Ontology-based models in pervasive computing systems
Pervasive computing is by its nature open and extensible, and must integrate the information from a diverse range of sources. This leads to a problem of information exchange, so sub-systems must agree on shared representations. Ontologies potentially ...
Juan Ye; Lorcan Coyle; Simon Dobson; Paddy Nixon
Putting the organization back into computational organization theory: a complex Perrowian model of organizational action
At best, computational models that study organizations incorporate only one perspective of how organizations are known to act within their environments. Such single-perspective models are limited in their generalizability and applicability to the real ... Keywords: Agent-based simulation, Computational organization theory, Organization theory, Organizational complexity
Brian W. Kulik; Timothy Baker
Computationally efficient modelling of pattern dependencies in the micro-embossing of thermoplastic polymers
We present a highly computationally efficient way to simulate the deformation of a polymeric layer when embossed with an arbitrarily patterned stamp. Two simplified material models are considered: a purely elastic model, which is useful when the material ... Keywords: Computer-aided design, Hot micro-embossing, PMMA, Pattern dependencies, Simulation
Hayden Taylor; Duane Boning; Ciprian Iliescu; Bangtao Chen
Application of soft computing models to hourly weather analysis in southern Saskatchewan, Canada
Accurate weather forecasts are necessary for planning our day-to-day activities. However, dynamic behavior of weather makes the forecasting a formidable challenge. This study presents a soft computing model based on a radial basis function network (RBFN) ... Keywords: Artificial neural networks, Decision support, Forecasting, Modeling, Simulation, Soft computing, Weather
Imran Maqsood; Muhammad Riaz Khan; Guo H. Huang; Rifaat Abdalla
Dose Reconstruction Using Computational Modeling of Handling a Particular Arsenic-73/Arsenic-74 Source
A special work evolution was performed at Los Alamos National Laboratory (LANL) with a particular 73As/74As source but the worker�s extremity dosimeter did not appear to provide appropriate dosimetric information for the tasks performed. This prompted a reconstruction of the dose to the worker�s hands. The computer code MCNP was chosen to model the tasks that the worker performed to evaluate the potential nonuniform hand dose distribution. A model was constructed similar to the worker�s hands to represent the performed handling tasks. The model included the thumb, index finger, middle finger, and the palm. The dose was calculated at the 7 mg cm-2 skin depth. To comply with the Code of Federal Regulations, 10 CFR 835, the 100 cm2 area that received the highest dose must be calculated. It could be determined if the dose received by the worker exceeded any regulatory limit. The computer code VARSKIN was also used to provide results to compare with those from MCNP where applicable. The results from the MCNP calculations showed that the dose to the worker�s hands did not exceed the regulatory limit of 0.5 Sv (50 rem). The equivalent nonuniform dose was 0.126 Sv (12.6 rem) to the right hand and 0.082 Sv (8.2 rem) to the left hand.
Stallard, Alisha M.
Computer demonstration of an interactive modeling system for the study of global change and biogeochemistry
There is a need for visually oriented materials to aid in the study of global ecological science. Analysis of the carbon cycle is key to understanding Potential climate change. We have used satellite imagery along with global climate and soil texture data sets to simulate seasonal patterns in net carbon fixation and soil CO[sub 2] production. An interactive computer system is used to illustrate graphical results from various model scenarios of climate warming and land use change. These include global animations of monthly gridded CO[sub 2] exchange between the atmosphere and the terrestrial biosphere. This modeling demonstration highlights the importance of annual CO[sub 2] fluxes in tropical forests (40% of global totals) and the large carbon storage potential in boreal and arctic soils.
Klooster, S.A.; Potter, S. (NASA-Ames Research Center, Moffett Field, CA (United States)); Randerson, J. (Carnegie Institution of Washington, Stanford, CA (United States))
Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et
Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Al., 2009) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Biasi,_Et_Al.,_2009)&oldid=40142
Computer Models Design for Teaching and Learning using Easy Java Simulation
We are teachers who have benefited from the Open Source Physics (Brown, 2012; Christian, 2010; Esquembre, 2012) community's work and we would like to share some of the computer models and lesson packages that we have designed and implemented in five schools grade 11 to 12 classes. In a ground-up teacher-leadership (MOE, 2010) approach, we came together to learn, advancing the professionalism (MOE, 2009) of physics educators and improve students' learning experiences through suitable blend (Jaakkola, 2012) of real equipment and computer models where appropriate . We will share computer models that we have remixed from existing library of computer models into suitable learning environments for inquiry of physics customized (Wee & Mak, 2009) for the Advanced Level Physics syllabus (SEAB, 2010, 2012). We hope other teachers would find these computer models useful and remix them to suit their own context, design better learning activities and share them to benefit all humankind, becoming citizens for the world...
Wee, Loo Kang Lawrence; Goh, Khoon Song Aloysius; LyeYE, Sze Yee; Lee, Tat Leong; Xu, Weiming; Goh, Giam Hwee Jimmy; Ong, Chee Wah; Ng, Soo Kok; Lim, Ee-Peow; Lim, Chew Ling; Yeo, Wee Leng Joshua; Ong, Matthew; LimI, Kenneth Y T
Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing Based Approach
For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent- and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required {approx}100 hours until termination, whereas a parallel approach required only {approx}2.5 hours (42 compute nodes) - a 40x speed-up. Tools developed for this parallel execution are discussed.
Fillippi, Anthony [Texas A& M University; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University
Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing-Based Approach
Abstract For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent-and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required ~100 hours until termination, whereas a parallel approach required only ~2.5 hours (42 compute nodes) a 40x speed-up. Tools developed for this parallel execution are discussed.
Filippi, Anthony M [ORNL; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University
Computer modeling and experimental verification of figure-eight-shaped null-flux coil suspension system
This report discusses the computer modeling and experimental verification of the magnetic forces associated with a figure-eight-shaped null-flux coil suspension system. A set of computer codes called COILGDWY, were developed on the basis of the dynamic circuit model and verified by means of a laboratory model. The experimental verification was conducted with a rotating PVC drum, the surface of which held various types of figure-eight-shaped null-flux coils that interacted with a stationary permanent magnet. The transient and dynamic magnetic forces between the stationary magnet and the rotating conducting coils were measured and compared with results obtained from the computer model. Good agreement between the experimental results and computer simulations was obtained. The computer model can also be used to calculate magnetic forces in a large-scale magnetic-levitation system.
He, J.L.; Mulcahey, T.M.; Rote, D.M.; Kelly, T.
Computer modeling of gas flow and gas loading of rock in a bench blasting environment
Numerical modeling can contribute greatly to an understanding of the physics involved in the blasting process. This paper will describe the latest enhancements to the blast modeling code DMC (Distinct Motion Code) (Taylor and Preece, 1989) and will demonstrate the ability of DMC to model gas flow and rock motion in a bench blasting environment. DMC has been used previously to model rock motion associated with blasting in a cratering environment (Preece and Taylor, 1990) and in confined volume blasting associated with in-situ oil shale retorting (Preece, 1990 a b). These applications of DMC treated the explosive loading as force versus time functions on specific spheres which were adjusted to obtain correct face velocities. It was recognized that a great need in explosives modeling was the coupling of an ability to simulate gas flow with the rock motion simulation capability of DMC. This was accomplished by executing a finite difference code that computes gas flow through a porous media (Baer and Gross, 1989) in conjunction with DMC. The marriage of these two capabilities has been documented by Preece and Knudsen, 1991. The capabilities that have been added recently to DMC and which will be documented in this paper include: (1) addition of a new equation of state for the explosive gases; (2) modeling of gas flow and sphere loading in a bench environment. 8 refs., 5 figs.
Preece, D.S.; Baer, M.R. (Sandia National Labs., Albuquerque, NM (United States)); Knudsen, S.D. (RE/SPEC, Inc., Albuquerque, NM (United States))
Computational Fluid Dynamics Modeling of the Operation of a Flame Ionization Sensor
The sensors and controls research group at the United States Department of Energy (DOE) National Energy Technology Laboratory (NETL) is continuing to develop the Combustion Control and Diagnostics Sensor (CCADS) for gas turbine applications. CCADS uses the electrical conduction of the charged species generated during the combustion process to detect combustion instabilities and monitor equivalence ratio. As part of this effort, combustion models are being developed which include the interaction between the electric field and the transport of charged species. The primary combustion process is computed using a flame wrinkling model (Weller et. al. 1998) which is a component of the OpenFOAM toolkit (Jasak et. al. 2004). A sub-model for the transport of charged species is attached to this model. The formulation of the charged-species model similar that applied by Penderson and Brown (1993) for the simulation of laminar flames. The sub-model consists of an additional flux due to the electric field (drift flux) added to the equations for the charged species concentrations and the solution the electric potential from the resolved charge density. The subgrid interactions between the electric field and charged species transport have been neglected. Using the above procedure, numerical simulations are performed and the results compared with several recent CCADS experiments.
Huckaby, E.D.; Chorpening, B.T.; Thornton, J.D.
Modeling-Computer Simulations At Stillwater Area (Wisian & Blackwell, 2004)
Stillwater Area (Wisian & Blackwell, 2004) Stillwater Area (Wisian & Blackwell, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Stillwater Area (Wisian & Blackwell, 2004) Exploration Activity Details Location Stillwater Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown References Kenneth W. Wisian, David D. Blackwell (2004) Numerical Modeling Of Basin And Range Geothermal Systems Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Stillwater_Area_(Wisian_%26_Blackwell,_2004)&oldid=387304" Categories: Exploration Activities DOE Funded Activities What links here Related changes Special pages Printable version
The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.
Modeling-Computer Simulations At Chocolate Mountains Area (Alm, Et Al.,
Modeling-Computer Simulations At Chocolate Mountains Area (Alm, Et Al., Modeling-Computer Simulations At Chocolate Mountains Area (Alm, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Chocolate Mountains Area (Alm, Et Al., 2010) Exploration Activity Details Location Chocolate Mountains Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes "Shallow temperature gradient drilling began at the CMAGR in January of 2010. 13 temperature gradient holes were completed to a depth of 500' below ground surface. Sites were selected based on the compilation of previous exploration and resulting data is being integrated into the most recent geologic model. This model will form the basis for the selection of a
Modeling-Computer Simulations At Akutan Fumaroles Area (Kolker, Et Al.,
Modeling-Computer Simulations At Akutan Fumaroles Area (Kolker, Et Al., Modeling-Computer Simulations At Akutan Fumaroles Area (Kolker, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Akutan Fumaroles Area (Kolker, Et Al., 2010) Exploration Activity Details Location Akutan Fumaroles Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes "Conceptual Model: Based on conceptual models built primarily from MT and geochemical datasets, it appears that development of the Akutan geothermal resource for power and/or direct use may be feasible. These datasets point to a shallow, tabular aquifer(s) of 155-180degrees C (i.e., "outflow zone") and a deeper, hotter resource of >220degrees C (i.e., "upflow zone") that
Modeling-Computer Simulations At Raft River Geothermal Area (1983) | Open
Modeling-Computer Simulations At Raft River Geothermal Area (1983) Modeling-Computer Simulations At Raft River Geothermal Area (1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Raft River Geothermal Area (1983) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1983 Usefulness useful DOE-funding Unknown Exploration Basis Predict flow rate and porosity Notes The objectives of the physical modeling effort are to: (1) evaluate injection-backflow testing for fractured reservoirs under conditions of known reservoir parameters (porosity, fracture width, etc.); (2) study the mechanisms controlling solute transport in fracture systems; and (3) provide data for validation of numerical models that explicitly simulate
Modeling-Computer Simulations At San Juan Volcanic Field Area (Clarkson &
Modeling-Computer Simulations At San Juan Volcanic Field Area (Clarkson & Modeling-Computer Simulations At San Juan Volcanic Field Area (Clarkson & Reiter, 1987) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At San Juan Volcanic Field Area (Clarkson & Reiter, 1987) Exploration Activity Details Location San Juan Volcanic Field Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes In this study we combine thermal maturation models, based on the level of maturation of the Fruitland Formation coals, and time-dependet temperature models, based on heat-flow data in the San Juan region, to further investigate both the thermal history of the region and the nature of the influence of the San Juan volcanic field thermal source on the thermal
Proceedings First Workshop on Applications of Membrane computing, Concurrency and Agent-based modelling in POPulation biology
This volume contains the papers presented at the first International Workshop on Applications of Membrane Computing, Concurrency and Agent-based Modelling in Population Biology (AMCA-POP 2010) held in Jena, Germany on August 25th, 2010 as a satellite event of the 11th Conference on Membrane Computing (CMC11). The aim of the workshop is to investigate whether formal modelling and analysis techniques could be applied with profit to systems of interest for population biology and ecology. The considered modelling notations include membrane systems, Petri nets, agent-based notations, process calculi, automata-based notations, rewriting systems and cellular automata. Such notations enable the application of analysis techniques such as simulation, model checking, abstract interpretation and type systems to study systems of interest in disciplines such as population biology, ecosystem science, epidemiology, genetics, sustainability science, evolution and other disciplines in which population dynamics and interactions...
Milazzo, Paolo; 10.4204/EPTCS.33
In this report (prepared in collaboration with Prof. Jeong Whan Yoon, Deakin University, Melbourne, Australia) a research effort was made to develop a non associated flow rule for zirconium. Since Zr is a hexagonally close packed (hcp) material, it is impossible to describe its plastic response under arbitrary loading conditions with any associated flow rule (e.g. von Mises). As a result of strong tension compression asymmetry of the yield stress and anisotropy, zirconium displays plastic behavior that requires a more sophisticated approach. Consequently, a new general asymmetric yield function has been developed which accommodates mathematically the four directional anisotropies along 0 degrees, 45 degrees, 90 degrees, and biaxial, under tension and compression. Stress anisotropy has been completely decoupled from the r value by using non associated flow plasticity, where yield function and plastic potential have been treated separately to take care of stress and r value directionalities, respectively. This theoretical development has been verified using Zr alloys at room temperature as an example as these materials have very strong SD (Strength Differential) effect. The proposed yield function reasonably well models the evolution of yield surfaces for a zirconium clock rolled plate during in plane and through thickness compression. It has been found that this function can predict both tension and compression asymmetry mathematically without any numerical tolerance and shows the significant improvement compared to any reported functions. Finally, in the end of the report, a program of further research is outlined aimed at constructing tensorial relationships for the temperature and fluence dependent creep surfaces for Zr, Zircaloy 2, and Zircaloy 4.
Michael V. Glazoff; Jeong-Whan Yoon
Efficient thermal field computation in phase-field models
We solve the phase-field equations in two dimensions to simulate crystal growth in the low undercooling regime. The novelty is the use of a fast solver for the free space heat equation to compute the thermal field. This solver is based on the efficient ... Keywords: Crystal growth, Dendritic solidification, Diffusion equation, Fast solvers, Integral representation, Phase-field, Unbounded domain
Jing-Rebecca Li; Donna Calhoun; Lucien Brush
A basic model for proactive event-driven computing
During the movie "Source Code" there is a shift in the plot; from (initially) reacting to a train explosion that already occurred and trying to eliminate further explosions, to (later) changing the reality to avoid the original train explosion. Whereas ... Keywords: decision making, event processing, proactive computing
Yagil Engel; Opher Etzion; Zohar Feldman
Computational methods for kinetic models of magnetically confined plasmas
In this book authors present various types of nonlinear Fokker-Planck equations which require solution for the realistic computer simulation of magnetically confined plasmas. They present detailed mathematical arguements leading to numerically tractable simplifications and provide examples and applications bearing directly on the most recent technology in plasma research.
Killeeen, J.; Kerbel, G.D.; Mc Coy, M.G.; Mirin, A.A.
An integrated computer model of a solar updraft power plant
Renewable energy technologies are generally complex, requiring nonlinear simulation concepts. This holds true especially for solar updraft power plants, the scope of this treatment, which starts with a short introduction into their functioning. Then ... Keywords: Excel-Solver, Fast computer algorithms, Simulation of nonlinear processes, Solar electricity generation, Solar updraft power technology, Strong numerical nonlinearities
Wilfried B. Kr�Tzig
Model of the Feed Water System Including a Generic Model of the Deaerator for a Full Scope Combined Cycle Power Plant Simulator
This paper presents the modelling of the Feed water System and an original generic model for closed vessels containing a fluid in two phases at equilibrium conditions with an incondensable gas. The model was used for the deaerator of a Combined Cycle ... Keywords: deaerator, pressurised vessels model, feedwater simulation
Edgardo J. Roldan-Villasana; Ana K. Vazquez
Low-Order Modelling of Blade-Induced Turbulence for RANS Actuator Disk Computations of Wind and Tidal Turbines
Modelling of turbine blade-induced turbulence (BIT) is discussed within the framework of three-dimensional Reynolds-averaged Navier-Stokes (RANS) actuator disk computations. We first propose a generic (baseline) BIT model, which is applied only to the actuator disk surface, does not include any model coefficients (other than those used in the original RANS turbulence model) and is expected to be valid in the limiting case where BIT is fully isotropic and in energy equilibrium. The baseline model is then combined with correction functions applied to the region behind the disk to account for the effect of rotor tip vortices causing a mismatch of Reynolds shear stress between short- and long-time averaged flow fields. Results are compared with wake measurements of a two-bladed wind turbine model of Medici and Alfredsson [Wind Energy, Vol. 9, 2006, pp. 219-236] to demonstrate the capability of the new model.
Nishino, Takafumi
Modeling-Computer Simulations At Coso Geothermal Area (1980) | Open Energy
Modeling-Computer Simulations At Coso Geothermal Area (1980) Modeling-Computer Simulations At Coso Geothermal Area (1980) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Coso Geothermal Area (1980) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1980 Usefulness useful DOE-funding Unknown Exploration Basis Estimate thermal regime and potential of the system Notes A three-dimensional generalized linear inversion of the delta t* observations was performed using a three-layer model. A shallow zone of high attenuation exists within the upper 5 km in a region bounded by Coso Hot Springs, Devils Kitchen, and Sugarloaf Mountain probably corresponding to a shallow vapor liquid mixture or "lossy" near surface lithology.
Modeling-Computer Simulations At Coso Geothermal Area (2000) | Open Energy
Modeling-Computer Simulations At Coso Geothermal Area (2000) Modeling-Computer Simulations At Coso Geothermal Area (2000) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Coso Geothermal Area (2000) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 2000 Usefulness not indicated DOE-funding Unknown Exploration Basis Model ground subsidence using observations of satellite radar interferometry Notes The InSAR displacement data was inverted for the positions, geometry, and relative strengths of the deformation sources at depth using a nonlinear least squares minimization algorithm. Elastic solutions were used for a prolate uniformly pressurized spheroidal cavity in a semi-infinite body as
Modeling-Computer Simulations At Fish Lake Valley Area (Deymonaz, Et Al.,
Modeling-Computer Simulations At Fish Lake Valley Area (Deymonaz, Et Al., Modeling-Computer Simulations At Fish Lake Valley Area (Deymonaz, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Fish Lake Valley Area (Deymonaz, Et Al., 2008) Exploration Activity Details Location Fish Lake Valley Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes (4) synthesis of geologic mapping results and lithologic logs for 3_D geologic characterization of the prospect area; (5) compilation of relevant data from the foregoing sub_activities into a Geographic Information Systems (GIS) database for visualization and mapping, and to facilitate the development of an exploration model; and (6) development of a refined
Modeling-Computer Simulations At Hawthorne Area (Lazaro, Et Al., 2010) |
Modeling-Computer Simulations At Hawthorne Area (Lazaro, Et Al., 2010) Modeling-Computer Simulations At Hawthorne Area (Lazaro, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Hawthorne Area (Lazaro, Et Al., 2010) Exploration Activity Details Location Hawthorne Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes The Navy GPO has contracted the University of Nevada Reno Great Basin for Center for Geothermal Research to conduct additional field exploration at HAD. The tasks required by the Navy range from field mapping and water sampling; detailed mapping, to low angle sun photo interpretations, trenching, to 3-D seismic interpretations and modeling. References Michael Lazaro, Chris Page, Andy Tiedeman, Andrew Sabin, Steve
Modeling-Computer Simulations At Nw Basin & Range Region (Biasi, Et Al.,
Biasi, Et Al., Biasi, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Biasi, Et Al., 2009) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Nw_Basin_%26_Range_Region_(Biasi,_Et_Al.,_2009)&oldid=401461" Categories: Exploration Activities DOE Funded
An Approach to Integrate a Space-Time GIS Data Model with High Performance Computers
In this paper, we describe an approach to integrate a Space-Time GIS data model on a high performance computing platform. The Space-Time GIS data model has been developed on a desktop computing environment. We use the Space-Time GIS data model to generate GIS module, which organizes a series of remote sensing data. We are in the process of porting the GIS module into an HPC environment, in which the GIS modules handle large dataset directly via parallel file system. Although it is an ongoing project, authors hope this effort can inspire further discussions on the integration of GIS on high performance computing platforms.
Wang, Dali [ORNL; Zhao, Ziliang [University of Tennessee, Knoxville (UTK); Shaw, Shih-Lung [ORNL
User manual for GEOCOST: a computer model for geothermal cost analysis. Volume 2. Binary cycle version
A computer model called GEOCOST has been developed to simulate the production of electricity from geothermal resources and calculate the potential costs of geothermal power. GEOCOST combines resource characteristics, power recovery technology, tax rates, and financial factors into one systematic model and provides the flexibility to individually or collectively evaluate their impacts on the cost of geothermal power. Both the geothermal reservoir and power plant are simulated to model the complete energy production system. In the version of GEOCOST in this report, geothermal fluid is supplied from wells distributed throughout a hydrothermal reservoir through insulated pipelines to a binary power plant. The power plant is simulated using a binary fluid cycle in which the geothermal fluid is passed through a series of heat exchangers. The thermodynamic state points in basic subcritical and supercritical Rankine cycles are calculated for a variety of working fluids. Working fluids which are now in the model include isobutane, n-butane, R-11, R-12, R-22, R-113, R-114, and ammonia. Thermodynamic properties of the working fluids at the state points are calculated using empirical equations of state. The Starling equation of state is used for hydrocarbons and the Martin-Hou equation of state is used for fluorocarbons and ammonia. Physical properties of working fluids at the state points are calculated.
Huber, H.D.; Walter, R.A.; Bloomster, C.H.
Computer Vision and Human-Computer Interaction: artificial vision techniques and use cases with creating interfaces and interaction models.
??Here is described how Computer Vision could give improvements to Human-Computer Interaction. Starting from a brief description of computers and human beings, follows a description� (more)
Comite, Marco
Computer-Based Model of the MIT Research Reactor
A description is given of a model of the Massachusetts Institute of Technology Research Reactor (MITR) in which both the reactor's neutronic and thermal-hydraulic behaviors are replicated. The purpose of the model is to support control studies and the development of techniques for the automated diagnosis of reactivity transients. In particular, comparison of the model's predictions with actual measurements from the reactor will allow determination of whether the reactor is functioning as expected.
John A. Bernard; Lin-Wen Hu
Model-based computer-aided design environment for operational design
To meet the increasing market challenges in chemical industry, it is imperative to improve process design and the supportive computer-aided engineering tools so that they can support lifecycle activities. This research work proposes detailed mechanism ... Keywords: change management, computer-aided design, operational design, operational design modeling
Hossam A. Gabbar; Atsushi Aoyama; Yuji Naka
Service and Utility Oriented Distributed Computing Systems: Challenges and Opportunities for Modeling and Simulation Communities
for Modeling and Simulation Communities Rajkumar Buyya and Anthony Sulistio Grid Computing and Distributed- oriented computing systems such as Data Centers and Grids. We present various case studies on the use by the electrical power grid's pervasiveness and reliability, began exploring the design and development of a new
Buyya, Rajkumar
Modeling water resource systems using a service-oriented computing paradigm
Service-oriented computing is a software engineering paradigm that views complex software systems as an interconnected collection of distributed computational components. Each component has a defined web service interface that allows it to be loosely-coupled ... Keywords: Integrated modeling, Systems analysis, Water management, Web services
Jonathan L. Goodall; Bella F. Robinson; Anthony M. Castronova
Keeping the patient asleep and alive: Towards a computational cognitive model of disturbance management in anaesthesia
We have analysed rich, dynamic data about the behaviour of anaesthetists during the management of a simulated critical incident in the operating theatre. We use a paper based analysis and a partial implementation to further the development of a computational ... Keywords: Behavioural analysis, Computational cognitive modelling, Disturbance management
K. Keogh; E. A. Sonenberg
BPACK -- A computer model package for boiler reburning/co-firing performance evaluations. User`s manual, Volume 1
This manual presents and describes a package of computer models uniquely developed for boiler thermal performance and emissions evaluations by the Energy and Environmental Research Corporation. The model package permits boiler heat transfer, fuels combustion, and pollutant emissions predictions related to a number of practical boiler operations such as fuel-switching, fuels co-firing, and reburning NO{sub x} reductions. The models are adaptable to most boiler/combustor designs and can handle burner fuels in solid, liquid, gaseous, and slurried forms. The models are also capable of performing predictions for combustion applications involving gaseous-fuel reburning, and co-firing of solid/gas, liquid/gas, gas/gas, slurry/gas fuels. The model package is conveniently named as BPACK (Boiler Package) and consists of six computer codes, of which three of them are main computational codes and the other three are input codes. The three main codes are: (a) a two-dimensional furnace heat-transfer and combustion code: (b) a detailed chemical-kinetics code; and (c) a boiler convective passage code. This user`s manual presents the computer model package in two volumes. Volume 1 describes in detail a number of topics which are of general users` interest, including the physical and chemical basis of the models, a complete description of the model applicability, options, input/output, and the default inputs. Volume 2 contains a detailed record of the worked examples to assist users in applying the models, and to illustrate the versatility of the codes.
Wu, K.T.; Li, B.; Payne, R.
Modeling-Computer Simulations (Brikowski, 2001) | Open Energy...
not indicated DOE-funding Unknown References Tom H. Brikowski (2001) Modeling Supercritical Systems With Tough2- The Eoslsc Equation Of State Module And A Basin And Range...
Reversible computation as a model for the quantum measurement process
One-to-one reversible automata are introduced. Their applicability to a modelling of the quantum mechanical measurement process is discussed.
Karl Svozil
Computation of Thermal Fields with Non-Stationary Model at ...
Numerical experiments in the case of electron beam melting of different metals ... Multiscale Modeling of Nanoscale Precipitate Stability in Irradiated Materials.
Computational Modeling of Oxidation and Corrosion of Alloys in ...
To address the kinetic effect, a multi-faceted modeling approach is being developed at NETL/DOE to study oxidation kinetics under different length scales.
The Computational Modeling of Alloys at the Atomic scale
Different expressions for the embedding energies, densities, and pair potentials englobe a large diversity of similar models. From Equation 5 it appears clearly�...
Publicly Available Computer Models in the Hypercon program
... Virtual Concrete Electrical Conductivity Test. ... completed his Ph.D. thesis at the University of Gent in ... 4SIGHT does not currently model degradation. ...
Cielo Computational Environment Usage Model With Mappings to ACE Requirements for the General Availability User Environment Capabilities Release Version 1.1
Cielo is a massively parallel supercomputer funded by the DOE/NNSA Advanced Simulation and Computing (ASC) program, and operated by the Alliance for Computing at Extreme Scale (ACES), a partnership between Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL). The primary Cielo compute platform is physically located at Los Alamos National Laboratory. This Cielo Computational Environment Usage Model documents the capabilities and the environment to be provided for the Q1 FY12 Level 2 Cielo Capability Computing (CCC) Platform Production Readiness Milestone. This document describes specific capabilities, tools, and procedures to support both local and remote users. The model is focused on the needs of the ASC user working in the secure computing environments at Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, or Sandia National Laboratories, but also addresses the needs of users working in the unclassified environment. The Cielo Computational Environment Usage Model maps the provided capabilities to the tri-Lab ASC Computing Environment (ACE) Version 8.0 requirements. The ACE requirements reflect the high performance computing requirements for the Production Readiness Milestone user environment capabilities of the ASC community. A description of ACE requirements met, and those requirements that are not met, are included in each section of this document. The Cielo Computing Environment, along with the ACE mappings, has been issued and reviewed throughout the tri-Lab community.
Vigil,Benny Manuel [Los Alamos National Laboratory; Ballance, Robert [SNL; Haskell, Karen [SNL
Computer Modeling VRF Heat Pumps in Commercial Buildings using EnergyPlus
Variable Refrigerant Flow (VRF) heat pumps are increasingly used in commercial buildings in the United States. Monitored energy use of field installations have shown, in some cases, savings exceeding 30% compared to conventional heating, ventilating, and air-conditioning (HVAC) systems. A simulation study was conducted to identify the installation or operational characteristics that lead to energy savings for VRF systems. The study used the Department of Energy EnergyPlus? building simulation software and four reference building models. Computer simulations were performed in eight U.S. climate zones. The baseline reference HVAC system incorporated packaged single-zone direct-expansion cooling with gas heating (PSZ-AC) or variable-air-volume systems (VAV with reheat). An alternate baseline HVAC system using a heat pump (PSZ-HP) was included for some buildings to directly compare gas and electric heating results. These baseline systems were compared to a VRF heat pump model to identify differences in energy use. VRF systems combine multiple indoor units with one or more outdoor unit(s). These systems move refrigerant between the outdoor and indoor units which eliminates the need for duct work in most cases. Since many applications install duct work in unconditioned spaces, this leads to installation differences between VRF systems and conventional HVAC systems. To characterize installation differences, a duct heat gain model was included to identify the energy impacts of installing ducts in unconditioned spaces. The configuration of variable refrigerant flow heat pumps will ultimately eliminate or significantly reduce energy use due to duct heat transfer. Fan energy is also studied to identify savings associated with non-ducted VRF terminal units. VRF systems incorporate a variable-speed compressor which may lead to operational differences compared to single-speed compression systems. To characterize operational differences, the computer model performance curves used to simulate cooling operation are also evaluated. The information in this paper is intended to provide a relative difference in system energy use and compare various installation practices that can impact performance. Comparative results of VRF versus conventional HVAC systems include energy use differences due to duct location, differences in fan energy when ducts are eliminated, and differences associated with electric versus fossil fuel type heating systems.
Raustad, Richard
Comparison of Regional Clear-Sky Albedos Inferred from Satellite Observations and Model Computations
We have taken an important first step in validating climate models by comparing model and satellite inferred clear sky TOA (top-of-atmosphere) albedos. Model albodos were computed on a 1� � 1� latitude-longitude grid, allowing for variations in ...
B. P. Briegleb; P. Minnis; V. Ramanathan; E. Harrison
Assessment of GPU computational enhancement to a 2D flood model
This paper presents a study of the computational enhancement of a Graphics Processing Unit (GPU) enabled 2D flood model. The objectives are to demonstrate the significant speedup of a new GPU-enabled full dynamic wave flood model and to present the effect ... Keywords: 2D flood model, CUDA, Flood simulation, GPU programming
Alfred J. Kalyanapu; Siddharth Shankar; Eric R. Pardyjak; David R. Judi; Steven J. Burian
Modeling of EOG and electrode position optimization for human-computer interface
The aim of this work was to model electro-oculogram (EOG) to find optimal electrode positions for wearable human-computer interface system. The system is a head cap developed in our institute and with it we can measure EOG and facial electromyography ... Keywords: EOG, electrode positions, modeling, volume conductor model
Niina N�jd; Jari Hyttinen
Theoretical and computational studies of some bioreactor models
We study certain classical basic models for bioreactor simulation in case of batch mode with decay. It is shown that in many cases the two-dimensional differential system describing the dynamics of the substrate and biomass concentrations can be reduced ... Keywords: Batch mode, Bioreactor, Chemostat, Haldane/Andrews function, Microbial growth, Monod model
Rene Alt; Svetoslav Markov
from rain, solar radiation and other crucial weather events on an hourly basis. Both vapor and liquid sophisticated modeling software that gives you heat and moisture data and uses weather data files from all over of multi- layer building walls exposed to natural weather. The WUFI series models can handle contributions
A model of computation and representation in the brain
The brain is first and foremost a control system that is capable of building an internal representation of the external world, and using this representation to make decisions, set goals and priorities, formulate plans, and control behavior with intent ... Keywords: Brain modeling, Cognitive modeling, Human neocortex, Image processing, Knowledge representation, Perception, Reverse engineering the brain, Segmentation, Signals to symbols
James S. Albus
Modeling-Computer Simulations At Coso Geothermal Area (1999) | Open Energy
Modeling-Computer Simulations At Coso Geothermal Area (1999) Modeling-Computer Simulations At Coso Geothermal Area (1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Coso Geothermal Area (1999) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1999 Usefulness not indicated DOE-funding Unknown Exploration Basis To analyze attenuation and source properties Notes A multiple-empirical Green's function method was used to determine source properties of small (M -0.4 to 1.3) earthquakes and P-wave and S-wave attenuation at the Coso Geothermal Field. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method.
Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) |
Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Assembling Crustal Geophysical Data for Geothermal Exploration in the Great Basin, Louie and Coolbaugh. We have compiled velocity information from sources in the literature, results of previous seismic experiments and earthquake-monitoring projects, and data donated from mining, geothermal, and petroleum companies. We also collected (May 2002 and August 2004) two
New Set of Computational Tools and Models Expected to Help Enable Rapid
Set of Computational Tools and Models Expected to Help Enable Set of Computational Tools and Models Expected to Help Enable Rapid Development and Deployment of Carbon Capture Technologies New Set of Computational Tools and Models Expected to Help Enable Rapid Development and Deployment of Carbon Capture Technologies January 28, 2013 - 12:00pm Addthis Washington, DC - An eagerly anticipated suite of 21 computational tools and models to help enable rapid development and deployment of new carbon capture technologies is now available from the Carbon Capture Simulation Initiative (CCSI). Visit the CCSI website The toolset developed by CCSI, a public-private partnership led by the Office of Fossil Energy's (FE) National Energy Technology Laboratory (NETL), will help meet an urgent need by industry to take carbon capture
Computational intelligence methods: joint use in discrete event simulation model of logistics processes
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
Computational Models for Materials with Shape Memory: Towards a Systematic Description of Coupled Phenomena
In this paper we propose a systematic methodology for improving computational efficiency of models describing the dynamics of materials with memory as part of multilayered structures, in particular in thermoelectric shape memory alloys actuators. The ...
Roderick V. N. Melnik; Anthony J. Roberts
Soap Manufacturing TechnologyChapter 7 Kettle Saponification: Computer Modeling, Latest Trends, and Innovations
Soap Manufacturing Technology Chapter 7 Kettle Saponification: Computer Modeling, Latest Trends, and Innovations Surfactants and Detergents eChapters Surfactants - Detergents Press Downloadable pdf of\tChapter 7 K
Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard tissues imaging
Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard, the tomographic procedure used is adapted to broadband data acquired in scattering configurations while, Iterative Approximation, Soft Tissues Imaging, Hard Tissues Imaging, Breast, Bones 1. INTRODUCTION
Numerical investigation of the pulsed NF3 + H2 chemical laser using a model which includes rotational relaxation and semi-classical laser equations
Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF$sub 3$ + H$sub 2$ chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth)
Creighton, J.R.
Application of the TEMPEST computer code for simulating hydrogen distribution in model containment structures. [PWR; BWR
In this study several aspects of simulating hydrogen distribution in geometric configurations relevant to reactor containment structures were investigated using the TEMPEST computer code. Of particular interest was the performance of the TEMPEST turbulence model in a density-stratified environment. Computed results illustrated that the TEMPEST numerical procedures predicted the measured phenomena with good accuracy under a variety of conditions and that the turbulence model used is a viable approach in complex turbulent flow simulation.
Trent, D.S.; Eyler, L.L.
Computational Combustion
Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.
Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J
Plutonium explosive dispersal modeling using the MACCS2 computer code
The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ``Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants``. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology.
Steele, C.M.; Wald, T.L.; Chanin, D.I.
Scalable computational architecture for integrating biological pathway models
A grand challenge of systems biology is to model the cell. The cell is an integrated network of cellular functions. Each cellular function, such as immune response, cell division, metabolism or apoptosis, is defined by an ...
Shiva, V. A
Computational tools for modeling and measuring chromosome structure
DNA conformation within cells has many important biological implications, but there are challenges both in modeling DNA due to the need for specialized techniques, and experimentally since tracing out in vivo conformations ...
Ross, Brian Christopher
A Multidimensional Model for Aerosols: Description of Computational Analogs
The numerical algorithms which we use to simulate the advection, diffusion, sedimentation, coagulation and condensational growth of atmospheric aerosols are described. The model can be used in one, two, or three spatial dimensions. We develop the ...
O. B. Toon; R. P. Turco; D. Westphal; R. Malone; M. Liu
Integrated Computational Modeling of Materials for Nuclear Energy
Nuclear fuel and primary cooling system structural components are exposed to elevated ... models for safety and performance evaluation of nuclear reactors but also for the ... Continuum Theory of Defects and Materials Response to Irradiation
Emergency Response Equipment and Related Training: Airborne Radiological Computer System (Model II)
The materials included in the Airborne Radiological Computer System, Model-II (ARCS-II) were assembled with several considerations in mind. First, the system was designed to measure and record the airborne gamma radiation levels and the corresponding latitude and longitude coordinates, and to provide a first overview look of the extent and severity of an accident's impact. Second, the portable system had to be light enough and durable enough that it could be mounted in an aircraft, ground vehicle, or watercraft. Third, the system must control the collection and storage of the data, as well as provide a real-time display of the data collection results to the operator. The notebook computer and color graphics printer components of the system would only be used for analyzing and plotting the data. In essence, the provided equipment is composed of an acquisition system and an analysis system. The data can be transferred from the acquisition system to the analysis system at the end of the data collection or at some other agreeable time.
David P. Colton
Simulation of Tailrace Hydrodynamics Using Computational Fluid Dynamics Models
This report investigates the feasibility of using computational fluid dynamics (CFD) tools to investigate hydrodynamic flow fields surrounding the tailrace zone below large hydraulic structures. Previous and ongoing studies using CFD tools to simulate gradually varied flow with multiple constituents and forebay/intake hydrodynamics have shown that CFD tools can provide valuable information for hydraulic and biological evaluation of fish passage near hydraulic structures. These studies however are incapable of simulating the rapidly varying flow fields that involving breakup of the free-surface, such as those through and below high flow outfalls and spillways. Although the use of CFD tools for these types of flow are still an active area of research, initial applications discussed in this report show that these tools are capable of simulating the primary features of these highly transient flow fields.
Cook, Chris B; Richmond, Marshall C
User manual for GEOCITY: a computer model for geothermal district heating cost analysis
A computer model called GEOCITY has been developed to systematically calculate the potential cost of district heating using hydrothermal geothermal resources. GEOCITY combines climate, demographic factors, and heat demand of the city, resource conditions, well drilling costs, design of the distribution system, tax rates, and financial factors into one systematic model. The GEOCITY program provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heat from a geothermal resource. Both the geothermal reservoir and distribution system are simulated to model the complete district heating system. GEOCITY consists of two major parts: the geothermal reservoir submodel and the distribution submodel. The reservoir submodel calculates the unit cost of energy by simulating the exploration, development, and operation of a geothermal reservoir and the transmission of this energy to a distribution center. The distribution submodel calculates the unit cost of heat by simulating the design and operation of a district heating distribution system. GEOCITY calculates the unit cost of energy and the unit cost of heat for the district heating system based on the principle that the present worth of the revenues will be equal to the present worth of the expenses including investment return over the economic life of the distribution system.
Huber, H.D.; McDonald, C.L.; Bloomster, C.H.; Schulte, S.C.
Computational fluid dynamics for LNG vapor dispersion modeling: a key parameters study
The increased demand for liquefied natural gas (LNG) has led to the construction of several new LNG terminals in the United States (US) and around the world. To ensure the safety of the public, consequence modeling is used to estimate the exclusion distances. The purpose of having these exclusion distances is to protect the public from being reached by flammable vapors during a release. For LNG industry, the exclusion zones are determined by the half lower flammability limits (half LFL, 2.5% V/V). Since LNG vapors are heavier?than?air when released into atmosphere, it goes through stages, negative, neutral and positive buoyant effect. In this process, it may reach the half LFL. The primary objective of this dissertation is to advance the status of LNG vapor dispersion modeling, especially for complex scenarios (i.e. including obstacle effects). The most used software, box models, cannot assess these complex scenarios. Box models simulate the vapor in a free?obstacle environment. Due to the advancement in computing, this conservative approach has become questionable. New codes as computational fluid dynamics (CFD) have been proven viable and more efficient than box models. The use of such advance tool in consequence modeling requires the refinement of some of the parameters. In these dissertation, these parameters were identified and refine through a series of field tests at the Brayton Firefighter Training Field (BFTF) as part of the Texas A&M University System (TAMUS). A total of five tests contributed to this dissertation, which three of them were designed and executed by the LNG team of the Mary Kay O'Connor Process Safety Center (MKOPSC) and the financial support from BP Global SPU Gas (BP). The data collected were used as calibration for a commercial CFD code called CFX from ANSYS. Once the CFD code was tuned, it was used in a sensitivity analysis to assess the effects of parameters in the LFL distance and the concentration levels. The dissertation discusses also the validity range for the key parameters.
Cormier, Benjamin Rodolphe
Developing a computationally efficient dynamic multilevel hybrid optimization scheme using multifidelity model interactions.
Many engineering application problems use optimization algorithms in conjunction with numerical simulators to search for solutions. The formulation of relevant objective functions and constraints dictate possible optimization algorithms. Often, a gradient based approach is not possible since objective functions and constraints can be nonlinear, nonconvex, non-differentiable, or even discontinuous and the simulations involved can be computationally expensive. Moreover, computational efficiency and accuracy are desirable and also influence the choice of solution method. With the advent and increasing availability of massively parallel computers, computational speed has increased tremendously. Unfortunately, the numerical and model complexities of many problems still demand significant computational resources. Moreover, in optimization, these expenses can be a limiting factor since obtaining solutions often requires the completion of numerous computationally intensive simulations. Therefore, we propose a multifidelity optimization algorithm (MFO) designed to improve the computational efficiency of an optimization method for a wide range of applications. In developing the MFO algorithm, we take advantage of the interactions between multi fidelity models to develop a dynamic and computational time saving optimization algorithm. First, a direct search method is applied to the high fidelity model over a reduced design space. In conjunction with this search, a specialized oracle is employed to map the design space of this high fidelity model to that of a computationally cheaper low fidelity model using space mapping techniques. Then, in the low fidelity space, an optimum is obtained using gradient or non-gradient based optimization, and it is mapped back to the high fidelity space. In this paper, we describe the theory and implementation details of our MFO algorithm. We also demonstrate our MFO method on some example problems and on two applications: earth penetrators and groundwater remediation.
Hough, Patricia Diane (Sandia National Laboratories, Livermore, CA); Gray, Genetha Anne (Sandia National Laboratories, Livermore, CA); Castro, Joseph Pete Jr. (; .); Giunta, Anthony Andrew
Modeling-Computer Simulations At U.S. West Region (Laney, 2005) | Open
Modeling-Computer Simulations At U.S. West Region Modeling-Computer Simulations At U.S. West Region (Laney, 2005) Exploration Activity Details Location U.S. West Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes Characterization and Conceptual Modeling of Magmatically-Heated and Deep-Circulation, High-Temperature Hydrothermal Systems in the Basin and Range and Cordilleran United States, Moore, Nash, Nemcok, Lutz, Norton, Kaspereit, Berard, van de Putte, Johnson and Deymonaz. Utilizing a wealth of formerly proprietary subsurface samples and datasets for exemplary high-temperature western U.S. geothermal systems, develop and publish detailed and refined new conceptual and numerical hydrothermal-history models of fundamental scientific import but, more importantly, of use to
Advanced Models, Applications and Software Systems for High Performance Computing
Spezifikation von Softwaresystemen. - In: Technische Zuverlässigkeit 1991. Berlin: VDE-Verl., 1991, S. 7-18-170. Bertoncini, R.; Jauho, A.P.: Gauge-invariant formulation of the intracollisional field effect including.J.; Harlander, M.K.; Lautenbacher, M.E.; Salazar, C.: Renormaliza- tion group analysis of charged Higgs effects
Middeldorp, Aart
CORCON-MOD3: An integrated computer model for analysis of molten core-concrete interactions. User`s manual
The CORCON-Mod3 computer code was developed to mechanistically model the important core-concrete interaction phenomena, including those phenomena relevant to the assessment of containment failure and radionuclide release. The code can be applied to a wide range of severe accident scenarios and reactor plants. The code represents the current state of the art for simulating core debris interactions with concrete. This document comprises the user`s manual and gives a brief description of the models and the assumptions and limitations in the code. Also discussed are the input parameters and the code output. Two sample problems are also given.
Bradley, D.R.; Gardner, D.R.; Brockmann, J.E.; Griffith, R.O. [Sandia National Labs., Albuquerque, NM (United States)
from rain, solar radiation and other crucial weather events on an hourly basis. Both vapor and liquid of multi- layer building walls exposed to natural weather. The WUFI series models can handle contributions and is free of charge. WUFI ORNL/IBP comes complete with weather data for scores of North-American cities
Computing the Electricity Market Equilibrium: Uses of market equilibrium models
]. On the demand side, considerable demand is simply not exposed to wholesale price variation, which greatly complicates the spec- ification of a demand model. Furthermore, the specification of electricity markets Engineer- ing, The University of Texas at Austin, Austin, TX 78712, USA (email: baldick
Baldick, Ross
Briefing package for the Yucca Flat pre-emptive review, including overview, UZ model, SZ volcanics model and summary and conclusions sections
Much progress has been made in the last several years in modeling radionuclide transport from tests conducted both in the unsaturated zone and saturated volcanic rocks of Yucca Flat, Nevada. The presentations to the DOE NNSA pre-emptive review panel contained herein document the progress to date, and discuss preliminary conclusions regarding the present and future extents of contamination resulting from past nuclear tests. The presentations also discuss possible strategies for addressing uncertainty in the model results.
Kwicklis, Edward Michael [Los Alamos National Laboratory; Keating, Elizabeth H [Los Alamos National Laboratory
Computer modeling of forced mixing in waste storage tanks
Numerical simulation results of fluid dynamic and physical processes in radioactive waste storage tanks are presented. Investigations include simulation of jet mixing pump induced flows intended to mix and maintain particulate material uniformly distributed throughout the liquid volume. Physical effects of solids are included in the code. These are particle size through a settling velocity and mixture properties through density and viscosity. Calculations have been accomplished for a centrally located, rotationally-oscillating, horizontally-directed jet mixing pump for two cases. One case is with low jet velocity and high settling velocity. It results in nonuniform distribution. The other case is with high jet velocity and low settling velocity. It results in uniform conditions. Results are being used to aid in experiment design and to understand mixing in the waste tanks. These results are to be used in conjunction with scaled experiments to define limits of pump operation to maintain uniformity of the mixture in the storage tanks during waste retrieval operations.
Eyler, L.L.; Michener, T.E.
Computational Modeling and Real-Time Control of Patient-Specific Laser Treatment of Cancer
Abstract�An adaptive feedback control system is presented which employs a computational model of bioheat transfer in living tissue to guide, in real-time, laser treatments of prostate cancer monitored by magnetic resonance thermal imaging. The system is built on what can be referred to as cyberinfrastructure�a complex structure of high-speed network, large-scale parallel computing devices, laser optics, imaging, visualizations, inverse-analysis algorithms, mesh generation, and control systems that guide laser therapy to optimally control the ablation of cancerous tissue. The computational system has been successfully tested on in vivo, canine prostate. Over the course of an 18 min laser-induced thermal therapy performed at M.D. Anderson Cancer Center (MDACC) in Houston, Texas, the computational models were calibrated to intra-operative real-time thermal imaging treatment data and the calibrated models controlled the bioheat transfer to within 5 �C of the predetermined treatment plan. The computational arena is in Austin, Texas and managed at the Institute for Computational Engineering and Sciences (ICES). The system is designed to control the bioheat transfer remotely while simultaneously providing real-time remote visualization of the on-going treatment. Post-operative histology of the canine prostate reveal that the damage region was within the targeted 1.2 cm diameter treatment objective. Keywords�Hyperthermia, Real-time computing, Medical imaging, Cancer treatment, Cyberinfrastructure, PDE
unknown authors
Back analysis of microplane model parameters using soft computing methods
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
Computational Computational
38 Computational complexity Computational complexity In 1965, the year Juris Hartmanis became Chair On the computational complexity of algorithms in the Transactions of the American Mathematical Society. The paper the best talent to the field. Theoretical computer science was immediately broadened from automata theory
Keinan, Alon
Liquefied Natural Gas (LNG) Vapor Dispersion Modeling with Computational Fluid Dynamics Codes
Federal regulation 49 CFR 193 and standard NFPA 59A require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. For modeling purposes, the physical process of dispersion of LNG release can be simply divided into two stages: source term and atmospheric dispersion. The former stage occurs immediately following the release where the behavior of fluids (LNG and its vapor) is mainly controlled by release conditions. After this initial stage, the atmosphere would increasingly dominate the vapor dispersion behavior until it completely dissipates. In this work, these two stages are modeled separately by a source term model and a dispersion model due to the different parameters used to describe the physical process at each stage. The principal focus of the source term study was on LNG underwater release, since there has been far less research conducted in developing and testing models for the source of LNG release underwater compared to that for LNG release onto land or water. An underwater LNG release test was carried out to understand the phenomena that occur when LNG is released underwater and to determine the characteristics of pool formation and the vapor cloud generated by the vaporization of LNG underwater. A mathematical model was used and validated against test data to calculate the temperature of the vapor emanating from the water surface. This work used the ANSYS CFX, a general-purpose computational fluid dynamics (CFD) package, to model LNG vapor dispersion in the atmosphere. The main advantages of CFD codes are that they have the capability of defining flow physics and allowing for the representation of complex geometry and its effects on vapor dispersion. Discussed are important parameters that are essential inputs to the ANSYS CFX simulations, including the mesh size and shape, atmospheric conditions, turbulence from the source term, ground surface roughness height, and effects of obstacles. A sensitivity analysis was conducted to illustrate the impact of key parameters on the accuracy of simulation results. In addition, a series of medium-scale LNG spill tests have been performed at the Brayton Fire Training Field (BFTF), College Station, TX. The objectives of these tests were to study key parameters of modeling the physical process of LNG vapor dispersion and collect data for validating the ANSYS CFX prediction results. A comparison of test data with simulation results demonstrated that CFX described the physical behavior of LNG vapor dispersion well, and its prediction results of distances to the half lower flammable limit were in good agreement with the test data.
Qi, Ruifeng
Computational fluid dynamics modelling of sewage sludge mixing in an anaerobic digester
In this paper, the development of a computational fluid dynamics (CFD) model to simulate the mechanical mixing of sewage sludge at laboratory scale is reported. The paper recommends a strategy for modelling mechanically mixed sewage sludge at laboratory ... Keywords: Biogas, CFD, Digestion, Energy, Non-Newtonian fluid, Sewage sludge, Turbulence
J. Bridgeman
A study of hardware performance monitoring counter selection in power modeling of computing systems
Power management and energy savings in high-performance computing has become an increasingly important design constraint. The foundation of many power/energy saving methods is based on power consumption models, which commonly rely on hardware performance ... Keywords: energy saving,performance monitoring counters,power modeling
Reza Zamani; Ahmad Afsahi
Coupling remote sensing with computational fluid dynamics modelling to estimate lake chlorophyll-a concentration
Coupling remote sensing with computational fluid dynamics modelling to estimate lake chlorophyll form 17 October 2000; accepted 1 June 2001 Abstract A remotely sensed image of Loch Leven, a shallow in the remotely sensed image. It is proposed that CFD modelling benefits the interpretation of remotely sensed
Exploring social structure effect on language evolution based on a computational model
A compositionality-regularity coevolution model is adopted to explore the effect of social structure on language emergence and maintenance. Based on this model, we explore language evolution in three experiments, and discuss the role of a popular agent ... Keywords: computational simulation, language evolution, power-law distribution, social structure
Tao Gong; James W. Minett; William S. -Y. Wang
High-performance computing tools for the integrated assessment and modelling of social-ecological systems
Integrated spatio-temporal assessment and modelling of complex social-ecological systems is required to address global environmental challenges. However, the computational demands of this modelling are unlikely to be met by traditional Geographic Information ... Keywords: AML, CPU, Cluster, Concurrency, Environmental, GIS, GPU, Global challenges, Graphics processing unit (GPU), Grid, HPC, Multi-core, NPV, Parallel programming
Brett A. Bryan
New vision tools from the comparative study of an "old" psychophysical and a "modern" computational model
A comparative study has been made between a one and half century old psychophysical model of vision and a modern computational model. The Mach band illusion has been studied from a new angle, that led to concluding that a Bi-Laplacian of Gaussian operation ...
Kuntal Ghosh; Sandip Sarkar; Kamales Bhaumik
Modeling-Computer Simulations At Obsidian Cliff Area (Hulen, Et Al., 2003)
Obsidian Cliff Area (Hulen, Et Al., 2003) Obsidian Cliff Area (Hulen, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Obsidian Cliff Area (Hulen, Et Al., 2003) Exploration Activity Details Location Obsidian Cliff Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown References Jeff Hulen, Denis Norton, Dennis Kaspereit, Larry Murray, Todd van de Putte, Melinda Wright (2003) Geology And A Working Conceptual Model Of The Obsidian Butte (Unit 6) Sector Of The Salton Sea Geothermal Field, California Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Obsidian_Cliff_Area_(Hulen,_Et_Al.,_2003)&oldid=388945" Category: Exploration
Modeling-Computer Simulations At Long Valley Caldera Area (Pribnow, Et Al.,
2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Long Valley Caldera Area (Pribnow, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Several fluid-flow models presented regarding the Long Valley Caldera. At shallow depths in the caldera References Daniel F. C. Pribnow, Claudia Schutze, Suzanne J. Hurter, Christina Flechsig, John H. Sass (2003) Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications From Thermal Data And Deep Electrical Sounding Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Long_Valley_Caldera_Area_(Pribnow,_Et_Al.,_2003)&oldid=389388
Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Heiken &
Heiken & Heiken & Goff, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Heiken & Goff, 1983) Exploration Activity Details Location Fenton Hill Hdr Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Development of a geologically-based model of the thermal and hydrothermal potential of the Fenton Hill HDR area. References Grant Heiken, Fraser Goff (1983) Hot Dry Rock Geothermal Energy In The Jemez Volcanic Field, New Mexico Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Fenton_Hill_Hdr_Geothermal_Area_(Heiken_%26_Goff,_1983)&oldid=511328
Modeling-Computer Simulations At General Us Region (Goff & Decker, 1983) |
Us Region (Goff & Decker, 1983) Us Region (Goff & Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At General Us Region (Goff & Decker, 1983) Exploration Activity Details Location General Us Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Review and identification of 24 potential sites for EGS development across the U.S., as well as modeling of the representative geologic systems in which promising EGS sites occur. References Fraser Goff, Edward R. Decker (1983) Candidate Sites For Future Hot Dry Rock Development In The United States Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_General_Us_Region_(Goff_%26_Decker,_1983)&oldid=38761
Modeling-Computer Simulations At Geysers Area (Goff & Decker, 1983) | Open
Decker, 1983) Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Geysers Area (Goff & Decker, 1983) Exploration Activity Details Location Geysers Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Review and identification of 24 potential sites for EGS development across the U.S., as well as modeling of the representative geologic systems in which promising EGS sites occur. References Fraser Goff, Edward R. Decker (1983) Candidate Sites For Future Hot Dry Rock Development In The United States Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Geysers_Area_(Goff_%26_Decker,_1983)&oldid=38676
Modeling-Computer Simulations At White Mountains Area (Goff & Decker, 1983)
White Mountains Area (Goff & Decker, 1983) White Mountains Area (Goff & Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At White Mountains Area (Goff & Decker, 1983) Exploration Activity Details Location White Mountains Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Review and identification of 24 potential sites for EGS development across the U.S., as well as modeling of the representative geologic systems in which promising EGS sites occur. References Fraser Goff, Edward R. Decker (1983) Candidate Sites For Future Hot Dry Rock Development In The United States Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_White_Mountains_Area_(Goff_%26_Decker,_1983)&oldid=387355"
Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Goff &
Decker, 1983) Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Fenton Hill Hdr Geothermal Area (Goff & Decker, 1983) Exploration Activity Details Location Fenton Hill Hdr Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Review and identification of 24 potential sites for EGS development across the U.S., as well as modeling of the representative geologic systems in which promising EGS sites occur. References Fraser Goff, Edward R. Decker (1983) Candidate Sites For Future Hot Dry Rock Development In The United States Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Fenton_Hill_Hdr_Geothermal_Area_(Goff_%26_Decker,_1983)&oldid=511326"
Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to
Modeling-Computer Simulations At Valles Caldera - Redondo Area (Wilt &
Redondo Area (Wilt & Redondo Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting gravity observations along profiles A--A' and B--B' (Talwani et al., 1959). Densities of 2.12, 2.40, and 2.65 g/cm a were used for modeling the near-surface caldera fill, the underlying volcanics, and the basement sections, respectively (Fig. 8). Although correlation with
Constructing Anatomically Accurate Face Models using Computed Tomography and Cyberware data
Facial animation and cranio-facial surgery simulation both stand to benefit from the development of anatomically accurate computer models of the human face. State-of-theart biomechanical models of the face have shown promise in animation, but they are inadequate for the purposes of cranio-facial surgery simulation. The goal of this thesis is to develop an improved facial model, using Cyberware data which captures the external structure and appearance of the face and head, as well as computed tomography (CT) data which captures the internal structure of facial soft and hard tissues. To this end, we develop algorithms to (1) register the CT and Cyberware datasets, (2) extract from the CT data a skull subsurface which serves as a foundation of the soft-tissue model, and (3) compute thic...
Faisal Zubair Qureshi
The Influence of Variations in Surface Treatment on 24-Hour Forecasts with a Limited Area Model, Including a Comparison of Modeled and Satellite-Measured Surface Temperatures
The effect of variations in surface parameters on 24-hour limited area forecasts has been examined on a day in July 1981. The vehicle for the study is a ten-level primitive equation model covering most of the continental United States. Variations ...
George Diak; Stacey Heikkinen; John Rates
A computer music instrumentarium
Chapter 6. COMPUTERS: To Solder or Not toMusic Models : A Computer Music Instrumentarium . . . . .Interactive Computer Systems . . . . . . . . . . . . . . 101
Oliver La Rosa, Jaime Eduardo
Computer Modeling of Photosynthesis Using the E-CELL System
Introduction The E-CELL syLLF is a generic software package for whole cell modeling and simulation developed by the Laboratory for Bioinformatics at Keio University [1]. Photosy thesis isgenerally characterized as the assimilation of CO 2 and H 2 O toy:;O O 2 and carbohyFAzxz usingenergy from sunlight, and can be expressed by the following process: 6CO 2 + 12H 2 O+ lightenergy -# C 6 H 12 O 6 +6O 2 +6H 2 O Photosy thesis occurs in two phases; . Light Reactions convertsenergy from the sun to ATP and NADPH. Electromagnetic radiation in the form of photons are absorbed by photoreceptor chlorophyor which are then transported through a series of elctron transport chainyinFHR+ O 2 , ATP and NADPH . Dark Reactions (Calvin Benson Cyson assimilates CO 2 , and the ATP, NAD
Emily Wang; Yoichi Nakayama; Masaru Tomita
Computational Human Performance Modeling For Alarm System Design
The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators� alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.
Jacques Hugo
Introduction to multidimensional combustion modeling with the CONCHAS-SPRAY computer program
CONCHAS-SPRAY is a finite-difference computer code for the calculation of two-dimensional chemically reacting fluid flows. In this paper we discuss four problem areas that are encountered in multidimensional numerical combustion modeling, and the numerical techniques used by CONCHAS-SPRAY to overcome these problems. Then the equations are given that are solved by the computer code, and some results from an example problem are discussed. 7 figures, 1 table.
O'Rourke, P.J.
The agent-based approach: A new direction for computational models of development
The agent-based approach emphasizes the importance of learning through organism-environment interaction. This approach is part of a recent trend in computational models of learning and development toward studying autonomous organisms that are embedded in virtual or real environments. In this paper we introduce the concepts of online and offline sampling and highlight the role of online sampling in agent-based models. After comparing the strengths of each approach for modeling particular developmental phenomena and research questions, we describe a recent agent-based model of infant causal perception. We conclude by discussing some of the present limitations of agent-based models and suggesting how these challenges may be addressed. � 2001 Academic Press Computational models of learning and development are playing an increasingly critical role in child development research (Cassidy, 1990;
Matthew Schlesinger; Domenico Parisi
Maximum Error Modeling for Fault-Tolerant Computation using Maximum a posteriori (MAP) Hypothesis
The application of current generation computing machines in safety-centric applications like implantable biomedical chips and automobile safety has immensely increased the need for reviewing the worst-case error behavior of computing devices for fault-tolerant computation. In this work, we propose an exact probabilistic error model that can compute the maximum error over all possible input space in a circuit specific manner and can handle various types of structural dependencies in the circuit. We also provide the worst-case input vector, which has the highest probability to generate an erroneous output, for any given logic circuit. We also present a study of circuit-specific error bounds for fault-tolerant computation in heterogeneous circuits using the maximum error computed for each circuit. We model the error estimation problem as a maximum a posteriori (MAP) estimate, over the joint error probability function of the entire circuit, calculated efficiently through an intelligent search of the entire input space using probabilistic traversal of a binary join tree using Shenoy-Shafer algorithm. We demonstrate this model using MCNC and ISCAS benchmark circuits and validate it using an equivalent HSpice model. Both results yield the same worst-case input vectors and the highest % difference of our error model over HSpice is just 1.23%. We observe that the maximum error probabilities are significantly larger than the average error probabilities, and provides a much tighter error bounds for fault-tolerant computation. We also find that the error estimates depend on the specific circuit structure and the maximum error probabilities are sensitive to the individual gate failure probabilities.
Karthikeyan Lingasubramanian; Syed M. Alam; Sanjukta Bhanja
Modeling-Computer Simulations At Nevada Test And Training Range Area
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Modeling-Computer Simulations At Nevada Test And Training Range Area (Sabin, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nevada Test And Training Range Area (Sabin, Et Al., 2004) Exploration Activity Details Location Nevada Test And Training Range Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Nellis Air Force Range (NAFR) occupies over 3 million acres in southern Nevada (Figure 1). We recently assessed potential utility-grade geothermal
Modeling-Computer Simulations At Walker-Lane Transitional Zone Region
Modeling-Computer Simulations At Walker-Lane Modeling-Computer Simulations At Walker-Lane Transitional Zone Region (Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Assembling Crustal Geophysical Data for Geothermal Exploration in the Great Basin, Louie and Coolbaugh. We have compiled velocity information from sources in the literature, results of previous seismic experiments and earthquake-monitoring projects, and data donated from mining, geothermal, and petroleum companies. We also collected (May 2002 and August 2004) two new crustal refraction profiles across western Nevada and the northern and central Sierra. These sections had not been well characterized previously.
A Review of Ground Coupled Heat Pump Models Used in Whole-Building Computer Simulation Programs
Increasingly, building owners are turning to ground source heat pump (GSHP) systems to improve energy efficiency. Ground-coupled heat pump (GCHP) systems with a vertical closed ground loop heat exchanger are one of the more widely used systems. Over the last thirty years, a number of simulation models have been developed to calculate the performance of the ground heat exchanger (GHX). The several computer programs can evaluate the GCHP systems as a part of the whole-building energy simulation. This paper briefly presents a general introduction to GSHP systems and the GCHP system, and reviews the currently developed GCHP models and compares computer programs for a GCHP design. In addition, GHX models which play an important role on the GCHP performance are reviewed. Finally, several widely recognized computer simulation programs for building energy analysis are compared regarding their GCHP simulation capability.
Do, S. L.; Haberl, J. S.
Verification of a VRF Heat Pump Computer Model in EnergyPlus
This paper provides verification results of the EnergyPlus variable refrigerant flow (VRF) heat pump computer model using manufacturer's performance data. The paper provides an overview of the VRF model, presents the verification methodology, and discusses the results. The verification provides quantitative comparison of full and part-load performance to manufacturer's data in cooling-only and heating-only modes of operation. The VRF heat pump computer model uses dual range bi-quadratic performance curves to represent capacity and Energy Input Ratio (EIR) as a function of indoor and outdoor air temperatures, and dual range quadratic performance curves as a function of part-load-ratio for modeling part-load performance. These performance curves are generated directly from manufacturer's published performance data. The verification compared the simulation output directly to manufacturer's performance data, and found that the dual range equation fit VRF heat pump computer model predicts the manufacturer's performance data very well over a wide range of indoor and outdoor temperatures and part-load conditions. The predicted capacity and electric power deviations are comparbale to equation-fit HVAC computer models commonly used for packaged and split unitary HVAC equipment.
Nigusse, Bereket; Raustad, Richard
A Hybrid MPI/OpenMP Approach for Parallel Groundwater Model Calibration on Multicore Computers
Groundwater model calibration is becoming increasingly computationally time intensive. We describe a hybrid MPI/OpenMP approach to exploit two levels of parallelism in software and hardware to reduce calibration time on multicore computers with minimal parallelization effort. At first, HydroGeoChem 5.0 (HGC5) is parallelized using OpenMP for a uranium transport model with over a hundred species involving nearly a hundred reactions, and a field scale coupled flow and transport model. In the first application, a single parallelizable loop is identified to consume over 97% of the total computational time. With a few lines of OpenMP compiler directives inserted into the code, the computational time reduces about ten times on a compute node with 16 cores. The performance is further improved by selectively parallelizing a few more loops. For the field scale application, parallelizable loops in 15 of the 174 subroutines in HGC5 are identified to take more than 99% of the execution time. By adding the preconditioned conjugate gradient solver and BICGSTAB, and using a coloring scheme to separate the elements, nodes, and boundary sides, the subroutines for finite element assembly, soil property update, and boundary condition application are parallelized, resulting in a speedup of about 10 on a 16-core compute node. The Levenberg-Marquardt (LM) algorithm is added into HGC5 with the Jacobian calculation and lambda search parallelized using MPI. With this hybrid approach, compute nodes at the number of adjustable parameters (when the forward difference is used for Jacobian approximation), or twice that number (if the center difference is used), are used to reduce the calibration time from days and weeks to a few hours for the two applications. This approach can be extended to global optimization scheme and Monte Carol analysis where thousands of compute nodes can be efficiently utilized.
Tang, Guoping [ORNL; D'Azevedo, Ed F [ORNL; Zhang, Fan [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Watson, David B [ORNL; Jardine, Philip M [ORNL
Computational modeling of phonetic and lexical learning in early language acquisition: Existing models and future directions
This work reviews a number of existing computational studies concentrated on the question of how spoken language can be learned from continuous speech in the absence of linguistically or phonetically motivated background knowledge, a situation faced ... Keywords: Computer simulation, Distributional learning, Language acquisition, Lexical learning, Phonetic learning
Okko R�S�Nen
A Kinetic Modeling study on the Oxidation of Primary Reference Fuel?Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics
A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.
Sakai, Y; Miyoshi, A; Koshi, M; Pitz, W J
Modeling-Computer Simulations At Raft River Geothermal Area (1980) | Open
80) 80) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Raft River Geothermal Area (1980) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Modeling-Computer Simulations Activity Date 1980 Usefulness not indicated DOE-funding Unknown Exploration Basis From refined estimates of reservoir coefficients better predictions of interference effects and long-term drawdown in the wells can be made. Notes Analytic methods have been used during reservoir testing to calculate reservoir coefficients. However, anisotropy of the reservoir due to fractures has not been taken into account in these calculations and estimates of these coefficients need to be refined. In conjunction with the
A computational study of ethane cracking in cluster models of zeolite H-ZSM-5.
Protolytic cracking of ethane by zeolites has been studied using quantum-chemical techniques and a cluster model of the zeolite Broensted acid site. Previous computational studies have utilized small cluster models and have not accounted for the long-range effects of the zeolite lattice. These studies have found reaction barriers for cracking which are significantly higher than experimental values. In this work we used a larger zeolite cluster model containing five tetrahedral (Si, Al) atoms (denoted 5T) and searched for stationary points along one possible reaction path for cracking at the HF/6-31 G(d) level of theory. This path involves a multi-step cracking reaction, in which the proton is first transferred from the acid site to the adsorbed ethane molecule to form an ion-pair equilibrium complex. Subsequently the proton attacks the C-C bond to complete the cracking process. The activation barrier for cracking was calculated, including corrections for (i) vibrational energies at the experimental reaction temperature of 773 K; (ii) electron correlation and an extended basis set at the B3LYP/6-311+G(3df,2p) level; and (iii) the influence of the surrounding zeolite lattice in H-ZSM-5. The barrier we obtain, 53 {+-} 5 kcal/mol, is significantly smaller than previous theoretical results and is in good agreement with typical experimental values for small hydrocarbons. Work is currently in progress to extend this study by carrying out geometry optimization of these complexes using the B3LYP method of density functional theory.
Zygmunt, S. A.
The Nuclear Energy Advanced Modeling and Simulation Enabling Computational Technologies FY09 Report
In this document we report on the status of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Enabling Computational Technologies (ECT) effort. In particular, we provide the context for ECT In the broader NEAMS program and describe the three pillars of the ECT effort, namely, (1) tools and libraries, (2) software quality assurance, and (3) computational facility (computers, storage, etc) needs. We report on our FY09 deliverables to determine the needs of the integrated performance and safety codes (IPSCs) in these three areas and lay out the general plan for software quality assurance to meet the requirements of DOE and the DOE Advanced Fuel Cycle Initiative (AFCI). We conclude with a brief description of our interactions with the Idaho National Laboratory computer center to determine what is needed to expand their role as a NEAMS user facility.
Diachin, L F; Garaizar, F X; Henson, V E; Pope, G
Modeling Warm Dense Matter Experiments using the 3D ALE-AMR Code and the Move Toward Exascale Computing
The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a 3 MeV, Li+ ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and transverse dimension of order 1 mm. The NDCX II will be used in studies of material in the warm dense matter (WDM) regime, and ion beam/hydrodynamic coupling experiments relevant to heavy ion based inertial fusion energy. We discuss recent efforts to adapt the 3D ALE-AMR code to model WDM experiments on NDCX II. The code, which combines Arbitrary Lagrangian Eulerian (ALE) hydrodynamics with Adaptive Mesh Refinement (AMR), has physics models that include ion deposition, radiation hydrodynamics, thermal diffusion, anisotropic material strength with material time history, and advanced models for fragmentation. Experiments at NDCX-II will explore the process of bubble and droplet formation (two-phase expansion) of superheated metal solids using ion beams. Experiments at higher temperatures will explore equation of state and heavy ion fusion beam-to-target energy coupling efficiency. Ion beams allow precise control of local beam energy deposition providing uniform volumetric heating on a timescale shorter than that of hydrodynamic expansion. The ALE-AMR code does not have any export control restrictions and is currently running at the National Energy Research Scientific Computing Center (NERSC) at LBNL and has been shown to scale well to thousands of CPUs. New surface tension models that are being implemented and applied to WDM experiments. Some of the approaches use a diffuse interface surface tension model that is based on the advective Cahn-Hilliard equations, which allows for droplet breakup in divergent velocity fields without the need for imposed perturbations. Other methods require seeding or other methods for droplet breakup. We also briefly discuss the effects of the move to exascale computing and related computational changes on general modeling codes in fusion energy.
Koniges, A; Eder, E; Liu, W; Barnard, J; Friedman, A; Logan, G; Fisher, A; Masers, N; Bertozzi, A
The NewFLOW Computational Model and Intermediate Format - Version 1.04
This report motivates and defines a general-purpose, architecture independent, parallel computational model, which captures the intuitions which underlie the design of the United Functions and Objects (UFO) programming language. The model has two aspects, which turn out to be a traditional dataflow model and an actor-like model, with a very simple interface between the two. Certain aspects of the model, particularly strictness, maximum parallelism, and lack of suspension are stressed. The implications of introducing stateful objects are carefully spelled out. The model has several purposes, although we primarily describe it as a vehicle for the compilation and optimisation of UFO, and for visualising the execution of programs. Having motivated the model, this report specifies, in detail, both the syntax and semantics of the model, and provides some examples of its use. 1 Motivation The primary purpose of this report is to define the semantics and syntax of NewFLOW, an intermediate rep...
Julian Seward; John Sargeant; Chris Kirkham
Computational Modeling
Oct 10, 2012 ... Program Organizers: Michael Gao, National Energy Technology Lab; Peter Liaw, University of Tennessee Wednesday 2:00 PM October 10�...
A novel decomposition and distributed computing approach for the solution of large scale optimization models
Abstract: Biomass feedstock production is an important component of the biomass based energy sector. Seasonal and distributed collection of low energy density material creates unique challenges, and optimization of the complete value chain is critical ... Keywords: Agent-based modeling, Biomass feedstock, Computation, Decomposition, Optimization
Yogendra Shastri; Alan Hansen; Luis Rodr�guez; K. C. Ting
Statistical Power and Performance Modeling for Optimizing the Energy Efficiency of Scientific Computing
High-performance computing (HPC) has become an indispensable resource in science and engineering, and it has oftentimes been referred to as the "thirdpillar" of science, along with theory and experimentation. Performance tuning is a key aspect in utilizing ... Keywords: energy-efficiency tuning, green supercomputing, regression modeling
Balaji Subramaniam; Wu-chun Feng
Computational investigation of early child language acquisition using multimodal neural networks: a review of three models
Current opinion suggests that language is a cognitive process in which different modalities such as perceptual entities, communicative intentions and speech are inextricably linked. As such, the process of child language acquisition is one in which the ... Keywords: Child language acquisition, Computational model, Control system, Neural network
Abel Nyamapfene
Computational Modeling and the Experimental Plasma Research Program A White Paper Submitted to the FESAC Subcommittee
Computational Modeling and the Experimental Plasma Research Program A White Paper Submitted of the fusion energy program. The experimental plasma research (EPR) program is well positioned to make major in fusion development and promote scientific discovery. Experimental plasma research projects explore
Computing combustion noise by combining Large Eddy Simulations with analytical models for the propagation of waves
Computing combustion noise by combining Large Eddy Simulations with analytical models +++++ Presented by Ignacio Duran Abstract Two mechanisms control combustion noise generation as shown by Marble. A method to calculate combustion-generated noise has been implemented in a tool called CHORUS. The method
Efficiently speeding up sequential computation through the n-way programming model
With core counts on the rise, the sequential components of applications are becoming the major bottleneck in performance scaling as predicted by Amdahl's law. We are therefore faced with the simultaneous problems of occupying an increasing number of ... Keywords: algorithmic diversity, n-way, parallel programming model, sequential computations, speedup
Romain E. Cledat; Tushar Kumar; Santosh Pande
A Computation of the Stratospheric Diabatic Circulation Using an Accurate Radiative Transfer Model
The global diabatic circulation is computed for the months of January, April, July and October over the altitude region 100 to 0.1 mb using an accurate troposphere-stratosphere radiative transfer model, SBUV and SME ozone data, and NMC ...
Joan E. Rosenfield; Mark R. Schoeberl; Marvin A. Geller
Computational modeling and experimental investigation of effects of compositional elements on interface and design aesthetics
This article describes computational modeling and two corresponding experimental investigations of the effects of symmetry, balance and quantity of construction elements on interface aesthetic judgments. In the first experiment, 30 black and white geometric ... Keywords: Aesthetics, Balance, Display evaluation, Engineering aesthetics, Symmetry
Michael Bauerly; Yili Liu
Computable General Equilibrium Models for the Analysis of Energy and Climate Policies
Computable General Equilibrium Models for the Analysis of Energy and Climate Policies Ian Sue Wing of the economy-wide impacts of energy and climate policies. JEL Classification: C68, D58, H22, Q43 Keywords of energy and environmental policies. Perhaps the most important of these applications is the analysis
Wing, Ian Sue
Computational trust and reputation models for open multi-agent systems: a review
In open environments, agents depend on reputation and trust mechanisms to evaluate the behavior of potential partners. The scientific research in this field has considerably increased, and in fact, reputation and trust mechanisms have been already considered ... Keywords: Cognitive trust and reputation, Computational trust and reputation models, Multiagent systems
Isaac Pinyol; Jordi Sabater-Mir
Organizational Performance Under Critical Situations�Exploring the Role of Computer Modeling in Crisis Case Analyses
Organizations sometimes face critical situations or crises that can induce severe consequences or even disasters if wrong decisions are made. The bulk of crisis management research has relied heavily on case study methods yet often with rhetorical or ... Keywords: case analysis, computer modeling, crisis management, organizational design
Zhiang Lin
Multiscale modeling and distributed computing to predict cosmesis outcome after a lumpectomy
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
BAYESIAN ESTIMATION OF HARDNESS RATIOS: MODELING AND COMPUTATIONS Taeyoung Park, 1
BAYESIAN ESTIMATION OF HARDNESS RATIOS: MODELING AND COMPUTATIONS Taeyoung Park, 1 Vinay L. Kashyap the nature of a photon spectrum is the socalled hardness ratio, which compares the numbers of counts observed in different passbands. The hardness ratio is especially useful to distinguish between
Wargelin, Bradford J.
BAYESIAN ESTIMATION OF HARDNESS RATIOS: MODELING AND COMPUTATIONS Taeyoung Park,1
BAYESIAN ESTIMATION OF HARDNESS RATIOS: MODELING AND COMPUTATIONS Taeyoung Park,1 Vinay L. Kashyap of a photon spectrum is the so-called hardness ratio, which compares the numbers of counts observed in different passbands. The hardness ratio is especially useful to distinguish between and categorize weak
Technical Review of the CENWP Computational Fluid Dynamics Model of the John Day Dam Forebay
The US Army Corps of Engineers Portland District (CENWP) has developed a computational fluid dynamics (CFD) model of the John Day forebay on the Columbia River to aid in the development and design of alternatives to improve juvenile salmon passage at the John Day Project. At the request of CENWP, Pacific Northwest National Laboratory (PNNL) Hydrology Group has conducted a technical review of CENWP's CFD model run in CFD solver software, STAR-CD. PNNL has extensive experience developing and applying 3D CFD models run in STAR-CD for Columbia River hydroelectric projects. The John Day forebay model developed by CENWP is adequately configured and validated. The model is ready for use simulating forebay hydraulics for structural and operational alternatives. The approach and method are sound, however CENWP has identified some improvements that need to be made for future models and for modifications to this existing model.
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.
Unit physics testing of a mix model in an eulerian fluid computation
A K-L turbulence mix model driven with a drag-buoyancy source term is tested in an Eulerian code in a series of basic unit-physics tests, as part of a mix validation milestone. The model and the closure coefficient values are derived in the work of Dimonte-Tipton [D-T] in Phys.Flu.18, 085101 (2006), and many of the test problems were reported there, where the mix model operated in Lagrange computations. The drag-buoyancy K-L mix model was implemented within the Eulerian code framework by A.J. Scannapieco. Mix model performance is evaluated in terms of mix width growth rates compared to experiments in select regimes. Results in our Eulerian code are presented for several unit-physics I-D test problems including the decay of homogeneous isotropic turbulence (HIT), Rayleigh-Taylor (RT) unstable mixing, shock amplification of initial turbulence, Richtmyer-Meshkov (RM) mixing in several single shock test cases and in comparison to two RM experiments including re-shock (Vetter-Sturtevant and Poggi, et.al.). Sensitivity to model parameters, to Atwood number, and to initial conditions are examined. Results here are in good agreement in some tests (HIT, RT) with the previous results reported for the mix model in the Lagrange calculations. The HIT turbulent decay agrees closely with analytic expectations, and the RT growth rate matches experimental values for the default values of the model coefficients proposed in [D-T]. Results for RM characterized with a power law growth rate differ from the previous mix model work but are still within the range for reasonable agreement with experiments. Sensitivity to IC values in the RM studies are examined; results are sensitive to initial values of L[t=O], which largely determines the RM mix layer growth rate, and generally differs from the IC values used in the RT studies. Result sensitivity to initial turbulence, K[t=O], is seen to be small but significant above a threshold value. Initial conditions can be adjusted so that single shock RM mix width results match experiments but we have not been able to obtain a good match for first shock and re-shock growth rates in the same experiment with a single set of parameters and Ie. Problematic issues with KH test problems are described. Resolution studies for an RM test problem show the K-L mix growth rate decreases as it converges at a supra-linear rate, and, convergence requires a fine grid (on the order of 10 microns). For comparison, a resolution study of a second mix model [Scannapieco and Cheng, Phys.Lett.A, 299(1),49, (2002)] acting on a two fluid interface problem was examined. The mix in this case was found to increase with grid resolution at low to moderate resolutions, but converged at comparably fine resolutions. In conclusion, these tests indicate that the Eulerian code K-L model, using the Dimonte Tipton default model closure coefficients, achieve reasonable results across many of the unit-physics experimental conditions. However, we were unable to obtain good matches simultaneously for shock and re-shock mix in a single experiment. Results are sensitive to initial conditions in the regimes under study, with different IC best suited to RT or RM mix. It is reasonable to expect IC sensitivity in extrapolating to high energy density regimes, or to experiments with deceleration due to arbitrary combinations of RT and RM. As a final comparison, the atomically generated mix fraction and the mix width were each compared for the K-L mix model and the Scannapieco model on an identical RM test problem. The Scannapieco mix fraction and width grow linearly. The K-L mix fraction and width grow with the same power law exponent, in contrast to expectations from analysis. In future work it is proposed to do more head-to-head comparisons between these two models and other mix model options on a full suite of physics test problems, such as interfacial deceleration due to pressure build-up during an idealized ICF implosion.
Vold, Erik [Los Alamos National Laboratory; Douglass, Rod [Los Alamos National Laboratory
Modeling-Computer Simulations At Northern Basin & Range Region (Blackwell,
Northern Basin & Northern Basin & Range Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to understand the nature of large scale constraints on the location and characteristics of the geothermal systems References D. D. Blackwell, K. W. Wisian, M. C. Richards, Mark Leidig, Richard Smith, Jason McKenna (2003) Geothermal Resource Analysis And Structure Of Basin And Range Systems, Especially Dixie Valley Geothermal Field, Nevada Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Blackwell,_Et_Al.,_2003)&oldid=401422
Modeling-Computer Simulations At Kilauea East Rift Area (Rudman & Epp,
Rudman & Epp, Rudman & Epp, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Kilauea East Rift Area (Rudman & Epp, 1983) Exploration Activity Details Location Kilauea East Rift Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Three models were generated: a constant temperature source from a vertical dike; a constant heat-generating magma chamber; and a transient heat source from a tapered vertical dike. Fair correlation is obtained between the HGP-A well temperature and the tapered dike 125 years after it is injected with an initial (transient) 1200degrees C temperature. Results provide background information from which to evaluate the importance of water
Modeling-Computer Simulations At Long Valley Caldera Area (Farrar, Et Al.,
3) 3) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Long Valley Caldera Area (Farrar, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Area Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Modeling of both deformation and microgravity data now suggests that (1) there are two inflation sources beneath the caldera, a shallower source 7^10 km beneath the resurgent dome and a deeper source V15 km beneath the caldera's south moat and (2) the shallower source may contain components of magmatic brine and gas. At shallow depths in the caldera References Christopher D. Farrar, Michael L. Sorey, Evelyn Roeloffs, Devin L.
User's guide for a personal computer model of turbulence at a wind turbine rotor
This document is primarily (1) a user's guide for the personal computer (PC) version of the code for the PNL computational model of the rotationally sampled wind speed (RODASIM11) and (2) a brief guide to the growing literature on the subject of rotationally sampled turbulence, from which the model is derived. The model generates values of turbulence experienced by single points fixed in the rotating frame of reference of an arbitrary wind turbine blade. The character of the turbulence depends on the specification of mean wind speed, the variance of turbulence, the crosswind and along-wind integral scales of turbulence, mean wind shear, and the hub height, radius, and angular speed of rotation of any point at which wind fluctuation is to be calculated. 13 refs., 4 figs., 4 tabs.
Connell, J.R.; Powell, D.C.; Gower, G.L.
Integrated modeling of CO2 storage and leakage scenarios including transitions between super- and sub-critical conditions, and phase change between liquid and gaseous CO2
Storage of CO{sub 2} in saline aquifers is intended to be at supercritical pressure and temperature conditions, but CO{sub 2} leaking from a geologic storage reservoir and migrating toward the land surface (through faults, fractures, or improperly abandoned wells) would reach subcritical conditions at depths shallower than 500-750 m. At these and shallower depths, subcritical CO{sub 2} can form two-phase mixtures of liquid and gaseous CO{sub 2}, with significant latent heat effects during boiling and condensation. Additional strongly non-isothermal effects can arise from decompression of gas-like subcritical CO{sub 2}, the so-called Joule-Thomson effect. Integrated modeling of CO{sub 2} storage and leakage requires the ability to model non-isothermal flows of brine and CO{sub 2} at conditions that range from supercritical to subcritical, including three-phase flow of aqueous phase, and both liquid and gaseous CO{sub 2}. In this paper, we describe and demonstrate comprehensive simulation capabilities that can cope with all possible phase conditions in brine-CO{sub 2} systems. Our model formulation includes: (1) an accurate description of thermophysical properties of aqueous and CO{sub 2}-rich phases as functions of temperature, pressure, salinity and CO{sub 2} content, including the mutual dissolution of CO{sub 2} and H{sub 2}O; (2) transitions between super- and subcritical conditions, including phase change between liquid and gaseous CO{sub 2}; (3) one-, two-, and three-phase flow of brine-CO{sub 2} mixtures, including heat flow; (4) non-isothermal effects associated with phase change, mutual dissolution of CO{sub 2} and water, and (de-) compression effects; and (5) the effects of dissolved NaCl, and the possibility of precipitating solid halite, with associated porosity and permeability change. Applications to specific leakage scenarios demonstrate that the peculiar thermophysical properties of CO{sub 2} provide a potential for positive as well as negative feedbacks on leakage rates, with a combination of self-enhancing and self-limiting effects. Lower viscosity and density of CO{sub 2} as compared to aqueous fluids provides a potential for self-enhancing effects during leakage, while strong cooling effects from liquid CO{sub 2} boiling into gas, and from expansion of gas rising towards the land surface, act to self-limit discharges. Strong interference between fluid phases under three-phase conditions (aqueous - liquid CO{sub 2} - gaseous CO{sub 2}) also tends to reduce CO{sub 2} fluxes. Feedback on different space and time scales can induce non-monotonic behavior of CO{sub 2} flow rates.
Pruess, K.
Sodium fast reactor gaps analysis of computer codes and models for accident analysis and reactor safety.
This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and identify important gaps. During the review, panel members identified over 60 computer codes that are currently available in the international community to perform different aspects of SFR safety analysis for various event scenarios and accident categories. A brief description of each of these codes together with references (when available) is provided. An adaptation of the Predictive Capability Maturity Model (PCMM) for computational modeling and simulation is described for use in this work. The panel's assessment of the available US codes is presented in the form of nine tables, organized into groups of three for each of three risk categories considered: anticipated operational occurrences (AOOs), design basis accidents (DBA), and beyond design basis accidents (BDBA). A set of summary conclusions are drawn from the results obtained. At the highest level, the panel judged that current US code capabilities are adequate for licensing given reasonable margins, but expressed concern that US code development activities had stagnated and that the experienced user-base and the experimental validation base was decaying away quickly.
Carbajo, Juan (Oak Ridge National Laboratory, Oak Ridge, TN); Jeong, Hae-Yong (Korea Atomic Energy Research Institute, Daejeon, Korea); Wigeland, Roald (Idaho National Laboratory, Idaho Falls, ID); Corradini, Michael (University of Wisconsin, Madison, WI); Schmidt, Rodney Cannon; Thomas, Justin (Argonne National Laboratory, Argonne, IL); Wei, Tom (Argonne National Laboratory, Argonne, IL); Sofu, Tanju (Argonne National Laboratory, Argonne, IL); Ludewig, Hans (Brookhaven National Laboratory, Upton, NY); Tobita, Yoshiharu (Japan Atomic Energy Agency, Ibaraki-ken, Japan); Ohshima, Hiroyuki (Japan Atomic Energy Agency, Ibaraki-ken, Japan); Serre, Frederic (Centre d'%C3%94etudes nucl%C3%94eaires de Cadarache %3CU%2B2013%3E CEA, France)
Handbook for personal computer versions enhanced oil recovery predictive models: Supporting technology for enhanced oil recovery
The personal computer (PC) programs described in this handbook were adapted from the Tertiary Oil Recovery Information System (TORIS) enhanced oil recovery (EOR) predictive models. The models, both those developed for the Department of Energy and those developed for the National Petroleum Council (NPC), were designed by Scientific Software-Intercomp and were used in the 1984 NPC study on the national potential for enhanced oil recovery. The Department of Energy, Bartlesville Project Office, supported the NPC study and has maintained the models since the study was completed. 10 refs.
Allison, E.; Waldrop, R.; Ray, R.M.
Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing
The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.
Held, Christian [Hochschul Institute Neckarsulm, Gottlieb-Daimler-Strasse 40, 74172 Neckarsulm (Germany); Liewald, Mathias; Schleich, Ralf [Institute for Metal Forming Technology, Universitaet Stuttgart, Stuttgart (Germany); Sindel, Manfred [AUDI AG, Neckarsulm (Germany)
HELIOS: a computer program for modeling the solar thermal test facility, a users guide
HELIOS is a flexible computer code for evaluations of proposed designs for central tower solar energy collector systems, for safety calculations on the threat to personnel and to the facility itself, for determination of how various input parameters alter the power collected, and for design trade-offs. Input variables include atmospheric transmission effects, reflector shape and surface errors, suntracking errors, focusing and alignment strategies, receiver design, placement positions of the tower and mirrors, time-of-day, and day-of-year for the calculation. Plotting and editing computer codes are available. Complete input instructions, code-structure details, and output explanation are given. The code is in use on CDC 6600 and CDC 7600 computers.
Vittitoe, C.N.; Biggs, F.; Lighthill, R.E.
Development of a model and computer code to describe solar grade silicon production processes. Fifth quarterly report
This program aims at developing mathematical models, and computer codes based on these models, which will allow prediction of the product distribution in chemical reactors in which gaseous silicon compounds are converted to condensed-phase silicon. The reactors to be modeled are flow reactors in which silane or one of the halogenated silanes is thermally decomposed or reacted with an alkali metal, H/sub 2/ or H atoms. Because the product of interest is particulate silicon, processes which must be modeled, in addition to mixing and reaction of gas-phase reactants, include the nucleation and growth of condensed Si via coagulation, condensation, and heterogeneous reaction. During this report period computer codes were developed and used to calculate: (1) coefficients for Si vapor and Si particles describing transport due to concentration and temperature gradients (i.e., Fick and Soret diffusion, respectively), and (2) estimates of thermochemical properties of Si n-mers. The former are needed to allow the mass flux of Si to reactor walls to be calculated. Because of the extremely large temperature gradients that exist in some of the reactors to be used in producing Si (particularly the Westinghouse reactor), it was found that thermal (Soret) diffusion can be the dominant transport mechanism for certain sizes of Si particles. The thermochemical estimates are required to allow computation of the formation rate of Si droplets. With the completion of these calculations the information and coding of the particle routines in the modified LAPP code is at the point where debugging can be done and that is now in progress.
Srivastava, R.; Gould, R.K.
DualTrust: A Trust Management Model for Swarm-Based Autonomic Computing Systems
Trust management techniques must be adapted to the unique needs of the application architectures and problem domains to which they are applied. For autonomic computing systems that utilize mobile agents and ant colony algorithms for their sensor layer, certain characteristics of the mobile agent ant swarm -- their lightweight, ephemeral nature and indirect communication -- make this adaptation especially challenging. This thesis looks at the trust issues and opportunities in swarm-based autonomic computing systems and finds that by monitoring the trustworthiness of the autonomic managers rather than the swarming sensors, the trust management problem becomes much more scalable and still serves to protect the swarm. After analyzing the applicability of trust management research as it has been applied to architectures with similar characteristics, this thesis specifies the required characteristics for trust management mechanisms used to monitor the trustworthiness of entities in a swarm-based autonomic computing system and describes a trust model that meets these requirements.
Maiden, Wendy M.
Mathematical and computer modelling reports: Modeling and forecasting energy markets with the intermediate future forecasting system
This paper describes the Intermediate Future Forecasting System (IFFS), which is the model used to forecast integrated energy markets by the U.S. Energy Information Administration. The model contains representations of supply and demand for all of the ...
Frederic H. Murphy; John J. Conti; Susan H. Shaw; Reginald Sanders
Optimization of a petroleum producing assets portfolio: development of an advanced computer model
Portfolios of contemporary integrated petroleum companies consist of a few dozen Exploration and Production (E&P) projects that are usually spread all over the world. Therefore, it is important not only to manage individual projects by themselves, but to also take into account different interactions between projects in order to manage whole portfolios. This study is the step-by-step representation of the method of optimizing portfolios of risky petroleum E&P projects, an illustrated method based on Markowitz�s Portfolio Theory. This method uses the covariance matrix between projects� expected return in order to optimize their portfolio. The developed computer model consists of four major modules. The first module generates petroleum price forecasts. In our implementation we used the price forecasting method based on Sequential Gaussian Simulation. The second module, Monte Carlo, simulates distribution of reserves and a set of expected production profiles. The third module calculates expected after tax net cash flows and estimates performance indicators for each realization, thus yielding distribution of return for each project. The fourth module estimates covariance between return distributions of individual projects and compiles them into portfolios. Using results of the fourth module, analysts can make their portfolio selection decisions. Thus, an advanced computer model for optimization of the portfolio of petroleum assets has been developed. The model is implemented in a MATLAB� computational environment and allows optimization of the portfolio using three different return measures (NPV, GRR, PI). The model has been successfully applied to the set of synthesized projects yielding reasonable solutions in all three return planes. Analysis of obtained solutions has shown that the given computer model is robust and flexible in terms of input data and output results. Its modular architecture allows further inclusion of complementary �blocks� that may solve optimization problems utilizing different measures (than considered) of risk and return as well as different input data formats.
Aibassov, Gizatulla
The Impact of IBM Cell Technology on the Programming Paradigm in the Context of Computer Systems for Climate and Weather Models
The call for ever-increasing model resolutions and physical processes in climate and weather models demands a continual increase in computing power. The IBM Cell processor's order-of-magnitude peak performance increase over conventional processors makes it very attractive to fulfill this requirement. However, the Cell's characteristics, 256KB local memory per SPE and the new low-level communication mechanism, make it very challenging to port an application. As a trial, we selected the solar radiation component of the NASA GEOS-5 climate model, which: (1) is representative of column physics components (half the total computational time), (2) has an extremely high computational intensity: the ratio of computational load to main memory transfers, and (3) exhibits embarrassingly parallel column computations. In this paper, we converted the baseline code (single-precision Fortran) to C and ported it to an IBM BladeCenter QS20. For performance, we manually SIMDize four independent columns and include several unrolling optimizations. Our results show that when compared with the baseline implementation running on one core of Intel's Xeon Woodcrest, Dempsey, and Itanium2, the Cell is approximately 8.8x, 11.6x, and 12.8x faster, respectively. Our preliminary analysis shows that the Cell can also accelerate the dynamics component (~;;25percent total computational time). We believe these dramatic performance improvements make the Cell processor very competitive as an accelerator.
Zhou, Shujia; Duffy, Daniel; Clune, Thomas; Suarez, Max; Williams, Samuel; Halem, Milton
Horizontal Heat Fluxes over Complex Terrain Computed Using a Simple Mixed-Layer Model and a Numerical Model
The thermally induced local circulation over a periodic valley is simulated by a two-dimensional numerical model that does not include condensational processes. During the daytime of a clear, calm day, heat is transported from the mountainous ...
Fujio Kimura; Tuneo Kuwagata
Polish contribution to the worldwide LHC computing
The computing requirements of LHC experiments, as well as their computing models, are briefly presented. The origin of grid technology and its development in high energy community is outlined, including the Polish participation. The LHC Computing Grid ... Keywords: LHC, Tier-2, WLCG, distributed computing, gLite, grid, high energy physics, middleware
Artur Binczewski; Micha$#322; Bluj; Antoni Cyz; Micha$#322; Dwu?nik; Maciej Filocha; ?ukasz Flis; Ryszard Gokieli; Jaros$#322;aw Iwaszkiewicz; Marek Kowalski; Patryk Laso$#324;; Rafa$#322; Lichwa$#322;a; Micha$#322; ?opuszy$#324;ski; Marek Magry$#347;; Piotr Malecki; Norbert Meyer; Krzysztof Nawrocki; Andrzej Olszewski; Andrzej Ozi?b$#322;o; Adam Pad�e; Henryk Pa$#322;ka; Marcin Pospieszny; Marcin Radecki; Rados$#322;aw Rowicki; Dorota Stojda; Marcin Stolarek; Tomasz Szepieniec; Tadeusz Szymocha; Micha$#322; Tura$#322;a; Karol Wawrzyniak; Wojciech Wi$#347;licki; Mariusz Witek; Pawe$#322; Wolniewicz
COBRA-SFS (Spent Fuel Storage): A thermal-hydraulic analysis computer code: Volume 1, Mathematical models and solution method
COBRA-SFS (Spent Fuel Storage) is a general thermal-hydraulic analysis computer code used to predict temperatures and velocities in a wide variety of systems. The code was refined and specialized for spent fuel storage system analyses for the US Department of Energy's Commercial Spent Fuel Management Program. The finite-volume equations governing mass, momentum, and energy conservation are written for an incompressible, single-phase fluid. The flow equations model a wide range of conditions including natural circulation. The energy equations include the effects of solid and fluid conduction, natural convection, and thermal radiation. The COBRA-SFS code is structured to perform both steady-state and transient calculations: however, the transient capability has not yet been validated. This volume describes the finite-volume equations and the method used to solve these equations. It is directed toward the user who is interested in gaining a more complete understanding of these methods.
Rector, D.R.; Wheeler, C.L.; Lombardo, N.J.
Marine and Hydrokinetic Technology (MHK) Instrumentation, Measurement, and Computer Modeling Workshop
Marine and Hydrokinetic Marine and Hydrokinetic Technology (MHK) Instrumentation, Measurement, and Computer Modeling Workshop W. Musial, M. Lawson, and S. Rooney National Renewable Energy Laboratory Technical Report NREL/TP-5000-57605 February 2013 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Marine and Hydrokinetic Technology (MHK) Instrumentation, Measurement, and Computer Modeling Workshop W. Musial, M. Lawson, and S. Rooney National Renewable Energy Laboratory Prepared under Task No. WA09.3406
Computational Modeling and Assessment of Nanocoatings for Ultra-Supercritical Boilers
Forced outages and boiler unavailability of coal-fired fossil plants is most often caused by fire-side corrosion of boiler water walls and tubing. Reliable coatings are required for ultra-supercritical application to mitigate corrosion because these boilers will operate at much higher temperatures and pressures than in supercritical boilers.Computational modeling efforts have been undertaken to design and assess potentialFe-Cr-Ni-Al systems to produce stable nanocrystalline ...
NREL Computer Models Integrate Wind Turbines with Floating Platforms (Fact Sheet)
Far off the shores of energy-hungry coastal cities, powerful winds blow over the open ocean, where the water is too deep for today's seabed-mounted offshore wind turbines. For the United States to tap into these vast offshore wind energy resources, wind turbines must be mounted on floating platforms to be cost effective. Researchers at the National Renewable Energy Laboratory (NREL) are supporting that development with computer models that allow detailed analyses of such floating wind turbines.
Spectroscopy, modeling and computation of metal chelate solubility in supercritical CO{sub 2}
The overall objectives of this project were to gain a fundamental understanding of the solubility and phase behavior of metal chelates in supercritical CO{sub 2}. Extraction with CO{sub 2} is an excellent way to remove organic compounds from soils, sludges and aqueous solutions, and recent research has demonstrated that, together with chelating agents, it is a viable way to remove metals, as well. In this project the authors sought to gain fundamental knowledge that is vital to computing phase behavior, and modeling and designing processes using CO{sub 2} to separate organics and metal compounds from DOE mixed wastes. The overall program was a comprehensive one to measure, model and compute the solubility of metal chelate complexes in supercritical CO{sub 2} and CO{sub 2}/cosolvent mixtures. Through a combination of phase behavior measurements, spectroscopy and the development of a new computational technique, the authors have achieved a completely reliable way to model metal chelate solubility in supercritical CO{sub 2} and CO{sub 2}/co-contaminant mixtures. Thus, they can now design and optimize processes to extract metals from solid matrices using supercritical CO{sub 2}, as an alternative to hazardous organic solvents that create their own environmental problems, even while helping in metals decontamination.
J. F. Brennecke; M. A. Stadtherr
Increasing the chemical content of turbulent flame models through the use of parallel computing
This report outlines the effort to model a time-dependent, 2- dimensional, turbulent, nonpremixed flame with full chemistry with the aid of parallel computing tools. In this study, the mixing process and the chemical reactions occurring in the flow field are described in terms of the single-point probability density function (PDF), while the turbulent viscosity is determined by the standard kappa-epsilon model. The initial problem solved is a H[sub 2]/Air flame whose chemistry is described by 28 elementary reactions involving 9 chemical species.
Yam, C.G.; Armstrong, R.; Koszykowski, M.L. [Sandia National Labs., Livermore, CA (United States); Chen, J.Y. [California Univ., Berkeley, CA (United States); Bui-Pham, M.N. [Lawrence Berkeley National Lab., CA (United States)
Three-Dimensional Computational Fluid Dynamics Modeling of Solid Oxide Electrolysis Cells and Stacks
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created for detailed analysis of a high-temperature electrolysis stack (solid oxide fuel cells operated as electrolyzers). Inlet and outlet plenum flow distributions are discussed. Maldistribution of plena flow show deviations in per-cell operating conditions due to non-uniformity of species concentrations. Models have also been created to simulate experimental conditions and for code validation. Comparisons between model predictions and experimental results are discussed. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the electrolysis mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition.
Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring
Unit physics performance of a mix model in Eulerian fluid computations
In this report, we evaluate the performance of a K-L drag-buoyancy mix model, described in a reference study by Dimonte-Tipton [1] hereafter denoted as [D-T]. The model was implemented in an Eulerian multi-material AMR code, and the results are discussed here for a series of unit physics tests. The tests were chosen to calibrate the model coefficients against empirical data, principally from RT (Rayleigh-Taylor) and RM (Richtmyer-Meshkov) experiments, and the present results are compared to experiments and to results reported in [D-T]. Results show the Eulerian implementation of the mix model agrees well with expectations for test problems in which there is no convective flow of the mass averaged fluid, i.e., in RT mix or in the decay of homogeneous isotropic turbulence (HIT). In RM shock-driven mix, the mix layer moves through the Eulerian computational grid, and there are differences with the previous results computed in a Lagrange frame [D-T]. The differences are attributed to the mass averaged fluid motion and examined in detail. Shock and re-shock mix are not well matched simultaneously. Results are also presented and discussed regarding model sensitivity to coefficient values and to initial conditions (IC), grid convergence, and the generation of atomically mixed volume fractions.
An Integrated Computer Modeling Environment For Regional Land Use, Air Quality, And Transportation Planning
The Land Use, Air Quality, and Transportation Integrated Modeling Environment (LATIME) represents an integrated approach to computer modeling and simulation of land use allocation, travel demand, and mobile source emissions for the Albuquerque, New Mexico, area. This environment provides predictive capability combined with a graphical and geographical interface. The graphical interface shows the causal relationships between data and policy scenarios and supports alternative model formulations. Scenarios are launched from within a Geographic Information System (GIS), and data produced by each model component at each time step within a simulation is stored in the GIS. A menudriven query system is utilized to review link-based results and regional and areawide results. These results can also be compared across time or between alternative land use scenarios. Using this environment, policies can be developed and implemented based on comparative analysis, rather than on single-step future pr...
Charles Hanley Renewable; Norman L. Marshall; Charles J. Hanley; Charles J. Hanley
A versatile computer model for the design and analysis of electric and hybrid vehicles
The primary purpose of the work reported in this thesis was to develop a versatile computer model to facilitate the design and analysis of hybrid vehicle drive-trains. A hybrid vehicle is one in which power for propulsion comes from two distinct sources, usually an internal combustion engine and an electric motor. Because of the design flexibility inherent in a propulsion system that has more than one source of energy, computer er modeling is necessary to identify which parameters are mainly responsible for the performance of the power-plant and to determine which designs are most viable. The modeling system described i@ this thesis was developed to accommodate a wide range of v