Advances in social simulation 2015

CERN Document Server

Verbrugge, Rineke; Flache, Andreas; Roo, Gert; Hoogduin, Lex; Hemelrijk, Charlotte

2017-01-01

This book highlights recent developments in the field, presented at the Social Simulation 2015 conference in Groningen, The Netherlands. It covers advances both in applications and methods of social simulation. Societal issues addressed range across complexities in economic systems, opinion dynamics and civil violence, changing mobility patterns, different land-use, transition in the energy system, food production and consumption, ecosystem management and historical processes. Methodological developments cover how to use empirical data in validating models in general, formalization of behavioral theory in agent behavior, construction of artificial populations for experimentation, replication of models, and agent-based models that can be run in a web browser. Social simulation is a rapidly evolving field. Social scientists are increasingly interested in social simulation as a tool to tackle the complex non-linear dynamics of society. Furthermore, the software and hardware tools available for social simulation ...

Large-scale agent-based social simulation : A study on epidemic prediction and control

NARCIS (Netherlands)

Zhang, M.

2016-01-01

Large-scale agent-based social simulation is gradually proving to be a versatile methodological approach for studying human societies, which could make contributions from policy making in social science, to distributed artificial intelligence and agent technology in computer science, and to theory

Computer Simulation of Multidimensional Archaeological Artefacts

Directory of Open Access Journals (Sweden)

Vera Moitinho de Almeida

2013-11-01

Full Text Available The main purpose of this ongoing research is to understand possible function(s of archaeological artefacts through Reverse Engineering processes. In addition, we intend to provide new data, as well as possible explications of the archaeological record according to what it expects about social activities and working processes, by simulating the potentialities of such actions in terms of input-output relationships. Our project focuses on the Neolithic lakeside site of La Draga (Banyoles, Catalonia. In this presentation we will begin by providing a clear overview of the major guidelines used to capture and process 3D digital data of several wooden artefacts. Then, we shall present the use of semi-automated relevant feature extractions. Finally, we intend to share preliminary computer simulation issues.

Application of computer virtual simulation technology in 3D animation production

Science.gov (United States)

Mo, Can

2017-11-01

In the continuous development of computer technology, the application system of virtual simulation technology has been further optimized and improved. It also has been widely used in various fields of social development, such as city construction, interior design, industrial simulation and tourism teaching etc. This paper mainly introduces the virtual simulation technology used in 3D animation. Based on analyzing the characteristics of virtual simulation technology, the application ways and means of this technology in 3D animation are researched. The purpose is to provide certain reference for the 3D effect promotion days after.

Simulation of quantum computers

NARCIS (Netherlands)

De Raedt, H; Michielsen, K; Hams, AH; Miyashita, S; Saito, K; Landau, DP; Lewis, SP; Schuttler, HB

2001-01-01

We describe a simulation approach to study the functioning of Quantum Computer hardware. The latter is modeled by a collection of interacting spin-1/2 objects. The time evolution of this spin system maps one-to-one to a quantum program carried out by the Quantum Computer. Our simulation software

Simulation of quantum computers

NARCIS (Netherlands)

Raedt, H. De; Michielsen, K.; Hams, A.H.; Miyashita, S.; Saito, K.

2000-01-01

We describe a simulation approach to study the functioning of Quantum Computer hardware. The latter is modeled by a collection of interacting spin-1/2 objects. The time evolution of this spin system maps one-to-one to a quantum program carried out by the Quantum Computer. Our simulation software

International Conference on Social Modeling and Simulation, plus Econophysics Colloquium 2014

CERN Document Server

Ito, Nobuyasu; Noda, Itsuki; Takayasu, Misako

2015-01-01

The proceedings of the international conference “SMSEC2014”, a joint conference of the first “Social Modeling and Simulations” and the 10th “Econophysics Colloquium”, held in Kobe in November 2014 with 174 participants, are gathered herein. Cutting edge scientific researches on various social phenomena are reviewed. New methods for analysis of big data such as financial markets, automobile traffics, epidemic spreading, world-trades and social media communications are provided to clarify complex interaction and distributions underlying in these social phenomena. Robustness and fragility of social systems are discussed based on agent models and complex network models. Techniques about high performance computers are introduced for simulation of complicated social phenomena. Readers will feel the researchers minds that deep and quantitative understanding will make it possible to realize comprehensive simulations of our whole society in the near future, which will contribute to wide fields of industry ...

System dynamic simulation: A new method in social impact assessment (SIA)

International Nuclear Information System (INIS)

Karami, Shobeir; Karami, Ezatollah; Buys, Laurie; Drogemuller, Robin

2017-01-01

Many complex social questions are difficult to address adequately with conventional methods and techniques, due to the complicated dynamics, and hard to quantify social processes. Despite these difficulties researchers and practitioners have attempted to use conventional methods not only in evaluative modes but also in predictive modes to inform decision making. The effectiveness of SIAs would be increased if they were used to support the project design processes. This requires deliberate use of lessons from retrospective assessments to inform predictive assessments. Social simulations may be a useful tool for developing a predictive SIA method. There have been limited attempts to develop computer simulations that allow social impacts to be explored and understood before implementing development projects. In light of this argument, this paper aims to introduce system dynamic (SD) simulation as a new predictive SIA method in large development projects. We propose the potential value of the SD approach to simulate social impacts of development projects. We use data from the SIA of Gareh-Bygone floodwater spreading project to illustrate the potential of SD simulation in SIA. It was concluded that in comparison to traditional SIA methods SD simulation can integrate quantitative and qualitative inputs from different sources and methods and provides a more effective and dynamic assessment of social impacts for development projects. We recommend future research to investigate the full potential of SD in SIA in comparing different situations and scenarios.

System dynamic simulation: A new method in social impact assessment (SIA)

Energy Technology Data Exchange (ETDEWEB)

Karami, Shobeir, E-mail: shobeirkarami@gmail.com [Agricultural Extension and Education, Shiraz University (Iran, Islamic Republic of); Karami, Ezatollah, E-mail: ekarami@shirazu.ac.ir [Agricultural Extension and Education, Shiraz University (Iran, Islamic Republic of); Buys, Laurie, E-mail: l.buys@qut.edu.au [Creative Industries Faculty, School of Design, Queensland University of Technology (Australia); Drogemuller, Robin, E-mail: robin.drogemuller@qut.edu.au [Creative Industries Faculty, School of Design, Queensland University of Technology (Australia)

2017-01-15

Many complex social questions are difficult to address adequately with conventional methods and techniques, due to the complicated dynamics, and hard to quantify social processes. Despite these difficulties researchers and practitioners have attempted to use conventional methods not only in evaluative modes but also in predictive modes to inform decision making. The effectiveness of SIAs would be increased if they were used to support the project design processes. This requires deliberate use of lessons from retrospective assessments to inform predictive assessments. Social simulations may be a useful tool for developing a predictive SIA method. There have been limited attempts to develop computer simulations that allow social impacts to be explored and understood before implementing development projects. In light of this argument, this paper aims to introduce system dynamic (SD) simulation as a new predictive SIA method in large development projects. We propose the potential value of the SD approach to simulate social impacts of development projects. We use data from the SIA of Gareh-Bygone floodwater spreading project to illustrate the potential of SD simulation in SIA. It was concluded that in comparison to traditional SIA methods SD simulation can integrate quantitative and qualitative inputs from different sources and methods and provides a more effective and dynamic assessment of social impacts for development projects. We recommend future research to investigate the full potential of SD in SIA in comparing different situations and scenarios.

FPGA-accelerated simulation of computer systems

CERN Document Server

Angepat, Hari; Chung, Eric S; Hoe, James C; Chung, Eric S

2014-01-01

To date, the most common form of simulators of computer systems are software-based running on standard computers. One promising approach to improve simulation performance is to apply hardware, specifically reconfigurable hardware in the form of field programmable gate arrays (FPGAs). This manuscript describes various approaches of using FPGAs to accelerate software-implemented simulation of computer systems and selected simulators that incorporate those techniques. More precisely, we describe a simulation architecture taxonomy that incorporates a simulation architecture specifically designed f

Massively parallel quantum computer simulator

NARCIS (Netherlands)

De Raedt, K.; Michielsen, K.; De Raedt, H.; Trieu, B.; Arnold, G.; Richter, M.; Lippert, Th.; Watanabe, H.; Ito, N.

2007-01-01

We describe portable software to simulate universal quantum computers on massive parallel Computers. We illustrate the use of the simulation software by running various quantum algorithms on different computer architectures, such as a IBM BlueGene/L, a IBM Regatta p690+, a Hitachi SR11000/J1, a Cray

Biomass Gasifier for Computer Simulation; Biomassa foergasare foer Computer Simulation

Energy Technology Data Exchange (ETDEWEB)

Hansson, Jens; Leveau, Andreas; Hulteberg, Christian [Nordlight AB, Limhamn (Sweden)

2011-08-15

This report is an effort to summarize the existing data on biomass gasifiers as the authors have taken part in various projects aiming at computer simulations of systems that include biomass gasification. Reliable input data is paramount for any computer simulation, but so far there is no easy-accessible biomass gasifier database available for this purpose. This study aims at benchmarking current and past gasifier systems in order to create a comprehensive database for computer simulation purposes. The result of the investigation is presented in a Microsoft Excel sheet, so that the user easily can implement the data in their specific model. In addition to provide simulation data, the technology is described briefly for every studied gasifier system. The primary pieces of information that are sought for are temperatures, pressures, stream compositions and energy consumption. At present the resulting database contains 17 gasifiers, with one or more gasifier within the different gasification technology types normally discussed in this context: 1. Fixed bed 2. Fluidised bed 3. Entrained flow. It also contains gasifiers in the range from 100 kW to 120 MW, with several gasifiers in between these two values. Finally, there are gasifiers representing both direct and indirect heating. This allows for a more qualified and better available choice of starting data sets for simulations. In addition to this, with multiple data sets available for several of the operating modes, sensitivity analysis of various inputs will improve simulations performed. However, there have been fewer answers to the survey than expected/hoped for, which could have improved the database further. However, the use of online sources and other public information has to some extent counterbalanced the low response frequency of the survey. In addition to that, the database is preferred to be a living document, continuously updated with new gasifiers and improved information on existing gasifiers.

Computational social dynamic modeling of group recruitment.

Energy Technology Data Exchange (ETDEWEB)

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.

2004-01-01

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.

Summer Computer Simulation Conference, Washington, DC, July 15-17, 1981, Proceedings

International Nuclear Information System (INIS)

Anon.

1981-01-01

Aspects of simulation technology are discussed, taking into account microcomputers in simulation, heuristic/adaptive systems, differential equations approaches, available simulation packages, selected operations research applications, and mathematical and statistical tools. Hybrid systems are discussed along with topics of chemical sciences. Subjects related to physical and engineering sciences are explored, giving attention to aeronautics and astronautics, physical processes, nuclear/electrical power technology, advanced computational methods and systems, avionics systems, dynamic systems analysis and control, and industrial systems. Environmental sciences are considered along with biomedical systems, managerial and social sciences, questions of simulation credibility and validation, and energy systems. A description is provided of simulation facilities, and topics related to system engineering and transportation are investigated

Distributed simulation of large computer systems

International Nuclear Information System (INIS)

Marzolla, M.

2001-01-01

Sequential simulation of large complex physical systems is often regarded as a computationally expensive task. In order to speed-up complex discrete-event simulations, the paradigm of Parallel and Distributed Discrete Event Simulation (PDES) has been introduced since the late 70s. The authors analyze the applicability of PDES to the modeling and analysis of large computer system; such systems are increasingly common in the area of High Energy and Nuclear Physics, because many modern experiments make use of large 'compute farms'. Some feasibility tests have been performed on a prototype distributed simulator

Leveraging Social Computing for Personalized Crisis Communication using Social Media

Science.gov (United States)

Leykin, Dmitry; Aharonson-Daniel, Limor; Lahad, Mooli

2016-01-01

Introduction: The extensive use of social media in modern life redefines social interaction and communication. Communication plays an important role in mitigating, or exacerbating, the psychological and behavioral responses to critical incidents and disasters. As recent disasters demonstrated, people tend to converge to social media during and following emergencies. Authorities can then use this media and other computational methods to gain insights from the public, mainly to enhance situational awareness, but also to improve their communication with the public and public adherence to instructions. Methods: The current review presents a conceptual framework for studying psychological aspects of crisis and risk communication using the social media through social computing. Results: Advanced analytical tools can be integrated in the processes and objectives of crisis communication. The availability of the computational techniques can improve communication with the public by a process of Hyper-Targeted Crisis Communication. Discussion: The review suggests that using advanced computational tools for target-audience profiling and linguistic matching in social media, can facilitate more sensitive and personalized emergency communication. PMID:27092290

Leveraging Social Computing for Personalized Crisis Communication using Social Media.

Science.gov (United States)

Leykin, Dmitry; Aharonson-Daniel, Limor; Lahad, Mooli

2016-03-24

The extensive use of social media in modern life redefines social interaction and communication. Communication plays an important role in mitigating, or exacerbating, the psychological and behavioral responses to critical incidents and disasters. As recent disasters demonstrated, people tend to converge to social media during and following emergencies. Authorities can then use this media and other computational methods to gain insights from the public, mainly to enhance situational awareness, but also to improve their communication with the public and public adherence to instructions. The current review presents a conceptual framework for studying psychological aspects of crisis and risk communication using the social media through social computing. Advanced analytical tools can be integrated in the processes and objectives of crisis communication. The availability of the computational techniques can improve communication with the public by a process of Hyper-Targeted Crisis Communication. The review suggests that using advanced computational tools for target-audience profiling and linguistic matching in social media, can facilitate more sensitive and personalized emergency communication.

Challenges in Computational Social Modeling and Simulation for National Security Decision Making

Science.gov (United States)

2011-06-01

34 Sociological Theory 25:268-291. Mead , George Herbert . 1913. "The social self." Journal of Philosophy, Psychology and Scientific Methods 10:374-380...Coastal Science and Policy, and University Distinguished Research Professor in the Department of Sociology with adjunct appointments in Biology...Hopkins Applied Physics Laboratory and formerly of the U.S. Defense Modeling and Simulation Office (DMSO) to discuss the history and importance of

Computer Modeling and Simulation

Energy Technology Data Exchange (ETDEWEB)

Pronskikh, V. S. [Fermilab

2014-05-09

Verification and validation of computer codes and models used in simulation are two aspects of the scientific practice of high importance and have recently been discussed by philosophers of science. While verification is predominantly associated with the correctness of the way a model is represented by a computer code or algorithm, validation more often refers to model’s relation to the real world and its intended use. It has been argued that because complex simulations are generally not transparent to a practitioner, the Duhem problem can arise for verification and validation due to their entanglement; such an entanglement makes it impossible to distinguish whether a coding error or model’s general inadequacy to its target should be blamed in the case of the model failure. I argue that in order to disentangle verification and validation, a clear distinction between computer modeling (construction of mathematical computer models of elementary processes) and simulation (construction of models of composite objects and processes by means of numerical experimenting with them) needs to be made. Holding on to that distinction, I propose to relate verification (based on theoretical strategies such as inferences) to modeling and validation, which shares the common epistemology with experimentation, to simulation. To explain reasons of their intermittent entanglement I propose a weberian ideal-typical model of modeling and simulation as roles in practice. I suggest an approach to alleviate the Duhem problem for verification and validation generally applicable in practice and based on differences in epistemic strategies and scopes

Cluster computing software for GATE simulations

International Nuclear Information System (INIS)

Beenhouwer, Jan de; Staelens, Steven; Kruecker, Dirk; Ferrer, Ludovic; D'Asseler, Yves; Lemahieu, Ignace; Rannou, Fernando R.

2007-01-01

Geometry and tracking (GEANT4) is a Monte Carlo package designed for high energy physics experiments. It is used as the basis layer for Monte Carlo simulations of nuclear medicine acquisition systems in GEANT4 Application for Tomographic Emission (GATE). GATE allows the user to realistically model experiments using accurate physics models and time synchronization for detector movement through a script language contained in a macro file. The downside of this high accuracy is long computation time. This paper describes a platform independent computing approach for running GATE simulations on a cluster of computers in order to reduce the overall simulation time. Our software automatically creates fully resolved, nonparametrized macros accompanied with an on-the-fly generated cluster specific submit file used to launch the simulations. The scalability of GATE simulations on a cluster is investigated for two imaging modalities, positron emission tomography (PET) and single photon emission computed tomography (SPECT). Due to a higher sensitivity, PET simulations are characterized by relatively high data output rates that create rather large output files. SPECT simulations, on the other hand, have lower data output rates but require a long collimator setup time. Both of these characteristics hamper scalability as a function of the number of CPUs. The scalability of PET simulations is improved here by the development of a fast output merger. The scalability of SPECT simulations is improved by greatly reducing the collimator setup time. Accordingly, these two new developments result in higher scalability for both PET and SPECT simulations and reduce the computation time to more practical values

Parallel reservoir simulator computations

International Nuclear Information System (INIS)

Hemanth-Kumar, K.; Young, L.C.

1995-01-01

The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

Computer simulation of ductile fracture

International Nuclear Information System (INIS)

Wilkins, M.L.; Streit, R.D.

1979-01-01

Finite difference computer simulation programs are capable of very accurate solutions to problems in plasticity with large deformations and rotation. This opens the possibility of developing models of ductile fracture by correlating experiments with equivalent computer simulations. Selected experiments were done to emphasize different aspects of the model. A difficult problem is the establishment of a fracture-size effect. This paper is a study of the strain field around notched tensile specimens of aluminum 6061-T651. A series of geometrically scaled specimens are tested to fracture. The scaled experiments are conducted for different notch radius-to-diameter ratios. The strains at fracture are determined from computer simulations. An estimate is made of the fracture-size effect

Simulating chemistry using quantum computers.

Science.gov (United States)

Kassal, Ivan; Whitfield, James D; Perdomo-Ortiz, Alejandro; Yung, Man-Hong; Aspuru-Guzik, Alán

2011-01-01

The difficulty of simulating quantum systems, well known to quantum chemists, prompted the idea of quantum computation. One can avoid the steep scaling associated with the exact simulation of increasingly large quantum systems on conventional computers, by mapping the quantum system to another, more controllable one. In this review, we discuss to what extent the ideas in quantum computation, now a well-established field, have been applied to chemical problems. We describe algorithms that achieve significant advantages for the electronic-structure problem, the simulation of chemical dynamics, protein folding, and other tasks. Although theory is still ahead of experiment, we outline recent advances that have led to the first chemical calculations on small quantum information processors.

HTTR plant dynamic simulation using a hybrid computer

International Nuclear Information System (INIS)

Shimazaki, Junya; Suzuki, Katsuo; Nabeshima, Kunihiko; Watanabe, Koichi; Shinohara, Yoshikuni; Nakagawa, Shigeaki.

1990-01-01

A plant dynamic simulation of High-Temperature Engineering Test Reactor has been made using a new-type hybrid computer. This report describes a dynamic simulation model of HTTR, a hybrid simulation method for SIMSTAR and some results obtained from dynamics analysis of HTTR simulation. It concludes that the hybrid plant simulation is useful for on-line simulation on account of its capability of computation at high speed, compared with that of all digital computer simulation. With sufficient accuracy, 40 times faster computation than real time was reached only by changing an analog time scale for HTTR simulation. (author)

GPU-accelerated micromagnetic simulations using cloud computing

Energy Technology Data Exchange (ETDEWEB)

Jermain, C.L., E-mail: clj72@cornell.edu [Cornell University, Ithaca, NY 14853 (United States); Rowlands, G.E.; Buhrman, R.A. [Cornell University, Ithaca, NY 14853 (United States); Ralph, D.C. [Cornell University, Ithaca, NY 14853 (United States); Kavli Institute at Cornell, Ithaca, NY 14853 (United States)

2016-03-01

Highly parallel graphics processing units (GPUs) can improve the speed of micromagnetic simulations significantly as compared to conventional computing using central processing units (CPUs). We present a strategy for performing GPU-accelerated micromagnetic simulations by utilizing cost-effective GPU access offered by cloud computing services with an open-source Python-based program for running the MuMax3 micromagnetics code remotely. We analyze the scaling and cost benefits of using cloud computing for micromagnetics. - Highlights: • The benefits of cloud computing for GPU-accelerated micromagnetics are examined. • We present the MuCloud software for running simulations on cloud computing. • Simulation run times are measured to benchmark cloud computing performance. • Comparison benchmarks are analyzed between CPU and GPU based solvers.

GPU-accelerated micromagnetic simulations using cloud computing

International Nuclear Information System (INIS)

Jermain, C.L.; Rowlands, G.E.; Buhrman, R.A.; Ralph, D.C.

2016-01-01

Highly parallel graphics processing units (GPUs) can improve the speed of micromagnetic simulations significantly as compared to conventional computing using central processing units (CPUs). We present a strategy for performing GPU-accelerated micromagnetic simulations by utilizing cost-effective GPU access offered by cloud computing services with an open-source Python-based program for running the MuMax3 micromagnetics code remotely. We analyze the scaling and cost benefits of using cloud computing for micromagnetics. - Highlights: • The benefits of cloud computing for GPU-accelerated micromagnetics are examined. • We present the MuCloud software for running simulations on cloud computing. • Simulation run times are measured to benchmark cloud computing performance. • Comparison benchmarks are analyzed between CPU and GPU based solvers.

The social impact of computers

CERN Document Server

Rosenberg, Richard S

1992-01-01

The Social Impact of Computers should be read as a guide to the social implications of current and future applications of computers. Among the basic themes presented are the following: the changing nature of work in response to technological innovation as well as the threat to jobs; personal freedom in the machine age as manifested by challenges to privacy, dignity, and work; the relationship between advances in computer and communications technology and the possibility of increased centralization of authority; and the emergence and influence of artificial intelligence and its role in decision

Computer Simulation Western

International Nuclear Information System (INIS)

Rasmussen, H.

1992-01-01

Computer Simulation Western is a unit within the Department of Applied Mathematics at the University of Western Ontario. Its purpose is the development of computational and mathematical methods for practical problems in industry and engineering and the application and marketing of such methods. We describe the unit and our efforts at obtaining research and development grants. Some representative projects will be presented and future plans discussed. (author)

Social Computing

CERN Multimedia

CERN. Geneva

2011-01-01

The past decade has witnessed a momentous transformation in the way people interact with each other. Content is now co-produced, shared, classified, and rated by millions of people, while attention has become the ephemeral and valuable resource that everyone seeks to acquire. This talk will describe how social attention determines the production and consumption of content within both the scientific community and social media, how its dynamics can be used to predict the future and the role that social media plays in setting the public agenda. About the speaker Bernardo Huberman is a Senior HP Fellow and Director of the Social Computing Lab at Hewlett Packard Laboratories. He received his Ph.D. in Physics from the University of Pennsylvania, and is currently a Consulting Professor in the Department of Applied Physics at Stanford University. He originally worked in condensed matter physics, ranging from superionic conductors to two-dimensional superfluids, and made contributions to the theory of critical p...

General-purpose parallel simulator for quantum computing

International Nuclear Information System (INIS)

Niwa, Jumpei; Matsumoto, Keiji; Imai, Hiroshi

2002-01-01

With current technologies, it seems to be very difficult to implement quantum computers with many qubits. It is therefore of importance to simulate quantum algorithms and circuits on the existing computers. However, for a large-size problem, the simulation often requires more computational power than is available from sequential processing. Therefore, simulation methods for parallel processors are required. We have developed a general-purpose simulator for quantum algorithms/circuits on the parallel computer (Sun Enterprise4500). It can simulate algorithms/circuits with up to 30 qubits. In order to test efficiency of our proposed methods, we have simulated Shor's factorization algorithm and Grover's database search, and we have analyzed robustness of the corresponding quantum circuits in the presence of both decoherence and operational errors. The corresponding results, statistics, and analyses are presented in this paper

Advanced computers and simulation

International Nuclear Information System (INIS)

Ryne, R.D.

1993-01-01

Accelerator physicists today have access to computers that are far more powerful than those available just 10 years ago. In the early 1980's, desktop workstations performed less one million floating point operations per second (Mflops), and the realized performance of vector supercomputers was at best a few hundred Mflops. Today vector processing is available on the desktop, providing researchers with performance approaching 100 Mflops at a price that is measured in thousands of dollars. Furthermore, advances in Massively Parallel Processors (MPP) have made performance of over 10 gigaflops a reality, and around mid-decade MPPs are expected to be capable of teraflops performance. Along with advances in MPP hardware, researchers have also made significant progress in developing algorithms and software for MPPS. These changes have had, and will continue to have, a significant impact on the work of computational accelerator physicists. Now, instead of running particle simulations with just a few thousand particles, we can perform desktop simulations with tens of thousands of simulation particles, and calculations with well over 1 million particles are being performed on MPPs. In the area of computational electromagnetics, simulations that used to be performed only on vector supercomputers now run in several hours on desktop workstations, and researchers are hoping to perform simulations with over one billion mesh points on future MPPs. In this paper we will discuss the latest advances, and what can be expected in the near future, in hardware, software and applications codes for advanced simulation of particle accelerators

Computer simulations of collisionless shock waves

International Nuclear Information System (INIS)

Leroy, M.M.

1984-01-01

A review of the contributions of particle computer simulations to the understanding of the physics of magnetic shock waves in collisionless plasmas is presented. The emphasis is on the relation between the computer simulation results, spacecraft observations of shocks in space, and related theories, rather than on technical aspects of the numerics. It is shown that much has been learned from the comparison of ISEE spacecraft observations of the terrestrial bow shock and particle computer simulations concerning the quasi-perpendicular, supercritical shock (ion scale structure, ion reflection mechanism and ultimate dissipation processes). Particle computer simulations have also had an appreciable prospective role in the investigation of the physics of quasi-parallel shocks, about which still little is known observationally. Moreover, these numerical techniques have helped to clarify the process of suprathermal ion rejection by the shock into the foreshock, and the subsequent evolution of the ions in the foreshock. 95 references

Computer-Assisted Face Processing Instruction Improves Emotion Recognition, Mentalizing, and Social Skills in Students with ASD

Science.gov (United States)

Rice, Linda Marie; Wall, Carla Anne; Fogel, Adam; Shic, Frederick

2015-01-01

This study examined the extent to which a computer-based social skills intervention called "FaceSay"™ was associated with improvements in affect recognition, mentalizing, and social skills of school-aged children with Autism Spectrum Disorder (ASD). "FaceSay"™ offers students simulated practice with eye gaze, joint attention,…

Computer algebra simulation - what can it do?; Was leistet Computer-Algebra-Simulation?

Energy Technology Data Exchange (ETDEWEB)

Braun, S. [Visual Analysis AG, Muenchen (Germany)

2001-07-01

Shortened development times require new and improved calculation methods. Numeric methods have long become state of the art. However, although numeric simulations provide a better understanding of process parameters, they do not give a feast overview of the interdependences between parameters. Numeric simulations are effective only if all physical parameters are sufficiently known; otherwise, the efficiency will decrease due to the large number of variant calculations required. Computer algebra simulation closes this gap and provides a deeper understanding of the physical fundamentals of technical processes. [German] Neue und verbesserte Berechnungsmethoden sind notwendig, um die staendige Verkuerzung der Entwicklungszyklen zu ermoeglichen. Herkoemmliche Methoden, die auf einem rein numerischen Ansatz basieren, haben sich in vielen Anwendungsbereichen laengst zum Standard entwickelt. Aber nicht nur die staendig kuerzer werdenden Entwicklungszyklen, sondern auch die weiterwachsende Komplexitaet machen es notwendig, ein besseres Verstaendnis der beteiligten Prozessparameter zu gewinnen. Die numerische Simulation besticht zwar durch Detailloesungen, selbst bei komplexen Strukturen und Prozessen, allerdings liefert sie keine schnelle Abschaetzung ueber die Zusammenhaenge zwischen den einzelnen Parametern. Die numerische Simulation ist nur dann effektiv, wenn alle physikalischen Parameter hinreichend bekannt sind; andernfalls sinkt die Effizienz durch die notwendige Anzahl von notwendigen Variantenrechnungen sehr stark. Die Computer-Algebra-Simulation schliesst diese Luecke in dem sie es erlaubt, sich einen tieferen Einblick in die physikalische Funktionsweise technischer Prozesse zu verschaffen. (orig.)

Framework for utilizing computational devices within simulation

Directory of Open Access Journals (Sweden)

Miroslav Mintál

2013-12-01

Full Text Available Nowadays there exist several frameworks to utilize a computation power of graphics cards and other computational devices such as FPGA, ARM and multi-core processors. The best known are either low-level and need a lot of controlling code or are bounded only to special graphic cards. Furthermore there exist more specialized frameworks, mainly aimed to the mathematic field. Described framework is adjusted to use in a multi-agent simulations. Here it provides an option to accelerate computations when preparing simulation and mainly to accelerate a computation of simulation itself.

Understanding Emergency Care Delivery Through Computer Simulation Modeling.

Science.gov (United States)

Laker, Lauren F; Torabi, Elham; France, Daniel J; Froehle, Craig M; Goldlust, Eric J; Hoot, Nathan R; Kasaie, Parastu; Lyons, Michael S; Barg-Walkow, Laura H; Ward, Michael J; Wears, Robert L

2018-02-01

In 2017, Academic Emergency Medicine convened a consensus conference entitled, "Catalyzing System Change through Health Care Simulation: Systems, Competency, and Outcomes." This article, a product of the breakout session on "understanding complex interactions through systems modeling," explores the role that computer simulation modeling can and should play in research and development of emergency care delivery systems. This article discusses areas central to the use of computer simulation modeling in emergency care research. The four central approaches to computer simulation modeling are described (Monte Carlo simulation, system dynamics modeling, discrete-event simulation, and agent-based simulation), along with problems amenable to their use and relevant examples to emergency care. Also discussed is an introduction to available software modeling platforms and how to explore their use for research, along with a research agenda for computer simulation modeling. Through this article, our goal is to enhance adoption of computer simulation, a set of methods that hold great promise in addressing emergency care organization and design challenges. © 2017 by the Society for Academic Emergency Medicine.

Numerical characteristics of quantum computer simulation

Science.gov (United States)

Chernyavskiy, A.; Khamitov, K.; Teplov, A.; Voevodin, V.; Voevodin, Vl.

2016-12-01

The simulation of quantum circuits is significantly important for the implementation of quantum information technologies. The main difficulty of such modeling is the exponential growth of dimensionality, thus the usage of modern high-performance parallel computations is relevant. As it is well known, arbitrary quantum computation in circuit model can be done by only single- and two-qubit gates, and we analyze the computational structure and properties of the simulation of such gates. We investigate the fact that the unique properties of quantum nature lead to the computational properties of the considered algorithms: the quantum parallelism make the simulation of quantum gates highly parallel, and on the other hand, quantum entanglement leads to the problem of computational locality during simulation. We use the methodology of the AlgoWiki project (algowiki-project.org) to analyze the algorithm. This methodology consists of theoretical (sequential and parallel complexity, macro structure, and visual informational graph) and experimental (locality and memory access, scalability and more specific dynamic characteristics) parts. Experimental part was made by using the petascale Lomonosov supercomputer (Moscow State University, Russia). We show that the simulation of quantum gates is a good base for the research and testing of the development methods for data intense parallel software, and considered methodology of the analysis can be successfully used for the improvement of the algorithms in quantum information science.

Development of a Computational Simulation Model for Conflict Management in Team Building

Directory of Open Access Journals (Sweden)

W. M. Wang

2011-05-01

Full Text Available Conflict management is one of the most important issues in leveraging organizational competitiveness. However, traditional social scientists built theories or models in this area which were mostly expressed in words and diagrams are insufficient. Social science research based on computational modeling and simulation is beginning to augment traditional theory building. Simulation provides a method for people to try their actions out in a way that is cost effective, faster, appropriate, flexible, and ethical. In this paper, a computational simulation model for conflict management in team building is presented. The model is designed and used to explore the individual performances related to the combination of individuals who have a range of conflict handling styles, under various types of resources and policies. The model is developed based on agent-based modeling method. Each of the agents has one of the five conflict handling styles: accommodation, compromise, competition, contingency, and learning. There are three types of scenarios: normal, convex, and concave. There are two types of policies: no policy, and a reward and punishment policy. Results from running the model are also presented. The simulation has led us to derive two implications concerning conflict management. First, a concave type of resource promotes competition, while convex type of resource promotes compromise and collaboration. Second, the performance ranking of different styles can be influenced by introducing different policies. On the other hand, it is possible for us to promote certain style by introducing different policies.

Analyzing Robotic Kinematics Via Computed Simulations

Science.gov (United States)

Carnahan, Timothy M.

1992-01-01

Computing system assists in evaluation of kinematics of conceptual robot. Displays positions and motions of robotic manipulator within work cell. Also displays interactions between robotic manipulator and other objects. Results of simulation displayed on graphical computer workstation. System includes both off-the-shelf software originally developed for automotive industry and specially developed software. Simulation system also used to design human-equivalent hand, to model optical train in infrared system, and to develop graphical interface for teleoperator simulation system.

Computer Simulations, Disclosure and Duty of Care

Directory of Open Access Journals (Sweden)

John Barlow

2006-05-01

Full Text Available Computer simulations provide cost effective methods for manipulating and modeling 'reality'. However they are not real. They are imitations of a system or event, real or fabricated, and as such mimic, duplicate or represent that system or event. The degree to which a computer simulation aligns with and reproduces the ‘reality’ of the system or event it attempts to mimic or duplicate depends upon many factors including the efficiency of the simulation algorithm, the processing power of the computer hardware used to run the simulation model, and the expertise, assumptions and prejudices of those concerned with designing, implementing and interpreting the simulation output. Computer simulations in particular are increasingly replacing physical experimentation in many disciplines, and as a consequence, are used to underpin quite significant decision-making which may impact on ‘innocent’ third parties. In this context, this paper examines two interrelated issues: Firstly, how much and what kind of information should a simulation builder be required to disclose to potential users of the simulation? Secondly, what are the implications for a decision-maker who acts on the basis of their interpretation of a simulation output without any reference to its veracity, which may in turn comprise the safety of other parties?

Creating science simulations through Computational Thinking Patterns

Science.gov (United States)

Basawapatna, Ashok Ram

Computational thinking aims to outline fundamental skills from computer science that everyone should learn. As currently defined, with help from the National Science Foundation (NSF), these skills include problem formulation, logically organizing data, automating solutions through algorithmic thinking, and representing data through abstraction. One aim of the NSF is to integrate these and other computational thinking concepts into the classroom. End-user programming tools offer a unique opportunity to accomplish this goal. An end-user programming tool that allows students with little or no prior experience the ability to create simulations based on phenomena they see in-class could be a first step towards meeting most, if not all, of the above computational thinking goals. This thesis describes the creation, implementation and initial testing of a programming tool, called the Simulation Creation Toolkit, with which users apply high-level agent interactions called Computational Thinking Patterns (CTPs) to create simulations. Employing Computational Thinking Patterns obviates lower behavior-level programming and allows users to directly create agent interactions in a simulation by making an analogy with real world phenomena they are trying to represent. Data collected from 21 sixth grade students with no prior programming experience and 45 seventh grade students with minimal programming experience indicates that this is an effective first step towards enabling students to create simulations in the classroom environment. Furthermore, an analogical reasoning study that looked at how users might apply patterns to create simulations from high- level descriptions with little guidance shows promising results. These initial results indicate that the high level strategy employed by the Simulation Creation Toolkit is a promising strategy towards incorporating Computational Thinking concepts in the classroom environment.

Simulation of a small computer of the TRA-1001 type on the BESM computer

International Nuclear Information System (INIS)

Galaktionov, V.V.

1975-01-01

Considered are the purpose and probable simulation ways of one computer by the other. The emulator (simulation program) is given for a small computer of TRA-1001 type on BESM-6 computer. The simulated computer basic elements are the following: memory (8 K words), central processor, input-output program channel, interruption circuit, computer panel. The work with the input-output devices, teletypes ASP-33, FS-1500 is also simulated. Under actual operation the emulator has been used for translating the programs prepared on punched cards with the aid of translator SLANG-1 by BESM-6 computer. The translator alignment from language COPLAN has been realized with the aid of the emulator

A computer-simulated liver phantom (virtual liver phantom) for multidetector computed tomography evaluation

Energy Technology Data Exchange (ETDEWEB)

Funama, Yoshinori [Kumamoto University, Department of Radiological Sciences, School of Health Sciences, Kumamoto (Japan); Awai, Kazuo; Nakayama, Yoshiharu; Liu, Da; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Miyazaki, Osamu; Goto, Taiga [Hitachi Medical Corporation, Tokyo (Japan); Hori, Shinichi [Gate Tower Institute of Image Guided Therapy, Osaka (Japan)

2006-04-15

The purpose of study was to develop a computer-simulated liver phantom for hepatic CT studies. A computer-simulated liver phantom was mathematically constructed on a computer workstation. The computer-simulated phantom was calibrated using real CT images acquired by an actual four-detector CT. We added an inhomogeneous texture to the simulated liver by referring to CT images of chronically damaged human livers. The mean CT number of the simulated liver was 60 HU and we added numerous 5-to 10-mm structures with 60{+-}10 HU/mm. To mimic liver tumors we added nodules measuring 8, 10, and 12 mm in diameter with CT numbers of 60{+-}10, 60{+-}15, and 60{+-}20 HU. Five radiologists visually evaluated similarity of the texture of the computer-simulated liver phantom and a real human liver to confirm the appropriateness of the virtual liver images using a five-point scale. The total score was 44 in two radiologists, and 42, 41, and 39 in one radiologist each. They evaluated that the textures of virtual liver were comparable to those of human liver. Our computer-simulated liver phantom is a promising tool for the evaluation of the image quality and diagnostic performance of hepatic CT imaging. (orig.)

Computer Simulations of Lipid Bilayers and Proteins

DEFF Research Database (Denmark)

Sonne, Jacob

2006-01-01

The importance of computer simulations in lipid bilayer research has become more prominent for the last couple of decades and as computers get even faster, simulations will play an increasingly important part of understanding the processes that take place in and across cell membranes. This thesis...... entitled Computer simulations of lipid bilayers and proteins describes two molecular dynamics (MD) simulation studies of pure lipid bilayers as well as a study of a transmembrane protein embedded in a lipid bilayer matrix. Below follows a brief overview of the thesis. Chapter 1. This chapter is a short...... in the succeeding chapters is presented. Details on system setups, simulation parameters and other technicalities can be found in the relevant chapters. Chapter 3, DPPC lipid parameters: The quality of MD simulations is intimately dependent on the empirical potential energy function and its parameters, i...

Radiotherapy Monte Carlo simulation using cloud computing technology.

Science.gov (United States)

Poole, C M; Cornelius, I; Trapp, J V; Langton, C M

2012-12-01

Cloud computing allows for vast computational resources to be leveraged quickly and easily in bursts as and when required. Here we describe a technique that allows for Monte Carlo radiotherapy dose calculations to be performed using GEANT4 and executed in the cloud, with relative simulation cost and completion time evaluated as a function of machine count. As expected, simulation completion time decreases as 1/n for n parallel machines, and relative simulation cost is found to be optimal where n is a factor of the total simulation time in hours. Using the technique, we demonstrate the potential usefulness of cloud computing as a solution for rapid Monte Carlo simulation for radiotherapy dose calculation without the need for dedicated local computer hardware as a proof of principal.

Radiotherapy Monte Carlo simulation using cloud computing technology

International Nuclear Information System (INIS)

Poole, C.M.; Cornelius, I.; Trapp, J.V.; Langton, C.M.

2012-01-01

Cloud computing allows for vast computational resources to be leveraged quickly and easily in bursts as and when required. Here we describe a technique that allows for Monte Carlo radiotherapy dose calculations to be performed using GEANT4 and executed in the cloud, with relative simulation cost and completion time evaluated as a function of machine count. As expected, simulation completion time decreases as 1/n for n parallel machines, and relative simulation cost is found to be optimal where n is a factor of the total simulation time in hours. Using the technique, we demonstrate the potential usefulness of cloud computing as a solution for rapid Monte Carlo simulation for radiotherapy dose calculation without the need for dedicated local computer hardware as a proof of principal.

Atomistic computer simulations a practical guide

CERN Document Server

Brazdova, Veronika

2013-01-01

Many books explain the theory of atomistic computer simulations; this book teaches you how to run them This introductory ""how to"" title enables readers to understand, plan, run, and analyze their own independent atomistic simulations, and decide which method to use and which questions to ask in their research project. It is written in a clear and precise language, focusing on a thorough understanding of the concepts behind the equations and how these are used in the simulations. As a result, readers will learn how to design the computational model and which parameters o

Fel simulations using distributed computing

NARCIS (Netherlands)

Einstein, J.; Biedron, S.G.; Freund, H.P.; Milton, S.V.; Van Der Slot, P. J M; Bernabeu, G.

2016-01-01

While simulation tools are available and have been used regularly for simulating light sources, including Free-Electron Lasers, the increasing availability and lower cost of accelerated computing opens up new opportunities. This paper highlights a method of how accelerating and parallelizing code

CUBESIM, Hypercube and Denelcor Hep Parallel Computer Simulation

International Nuclear Information System (INIS)

Dunigan, T.H.

1988-01-01

1 - Description of program or function: CUBESIM is a set of subroutine libraries and programs for the simulation of message-passing parallel computers and shared-memory parallel computers. Subroutines are supplied to simulate the Intel hypercube and the Denelcor HEP parallel computers. The system permits a user to develop and test parallel programs written in C or FORTRAN on a single processor. The user may alter such hypercube parameters as message startup times, packet size, and the computation-to-communication ratio. The simulation generates a trace file that can be used for debugging, performance analysis, or graphical display. 2 - Method of solution: The CUBESIM simulator is linked with the user's parallel application routines to run as a single UNIX process. The simulator library provides a small operating system to perform process and message management. 3 - Restrictions on the complexity of the problem: Up to 128 processors can be simulated with a virtual memory limit of 6 million bytes. Up to 1000 processes can be simulated

Accelerator simulation using computers

International Nuclear Information System (INIS)

Lee, M.; Zambre, Y.; Corbett, W.

1992-01-01

Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ''multi-track'' simulation and analysis code can be used for these applications

Computer Simulation in Information and Communication Engineering

CERN Multimedia

Anton Topurov

2005-01-01

CSICE'05 Sofia, Bulgaria 20th - 22nd October, 2005 On behalf of the International Scientific Committee, we would like to invite you all to Sofia, the capital city of Bulgaria, to the International Conference in Computer Simulation in Information and Communication Engineering CSICE'05. The Conference is aimed at facilitating the exchange of experience in the field of computer simulation gained not only in traditional fields (Communications, Electronics, Physics...) but also in the areas of biomedical engineering, environment, industrial design, etc. The objective of the Conference is to bring together lectures, researchers and practitioners from different countries, working in the fields of computer simulation in information engineering, in order to exchange information and bring new contribution to this important field of engineering design and education. The Conference will bring you the latest ideas and development of the tools for computer simulation directly from their inventors. Contribution describ...

Social and ethical dimensions of computer-mediated education.

NARCIS (Netherlands)

Brey, Philip A.E.

2006-01-01

This paper addresses social and ethical issues in computer-mediated education, with a focus on higher education. It will be argued if computer-mediated education is to be implemented in a socially and ethically sound way, four major social and ethical issues much be confronted. These are: (1) the

Protection motivation theory and social distancing behaviour in response to a simulated infectious disease epidemic.

Science.gov (United States)

Williams, Lynn; Rasmussen, Susan; Kleczkowski, Adam; Maharaj, Savi; Cairns, Nicole

2015-01-01

Epidemics of respiratory infectious disease remain one of the most serious health risks facing the population. Non-pharmaceutical interventions (e.g. hand-washing or wearing face masks) can have a significant impact on the course of an infectious disease epidemic. The current study investigated whether protection motivation theory (PMT) is a useful framework for understanding social distancing behaviour (i.e. the tendency to reduce social contacts) in response to a simulated infectious disease epidemic. There were 230 participants (109 males, 121 females, mean age 32.4 years) from the general population who completed self-report measures assessing the components of PMT. In addition, participants completed a computer game which simulated an infectious disease epidemic in order to provide a measure of social distancing behaviour. The regression analyses revealed that none of the PMT variables were significant predictors of social distancing behaviour during the simulation task. However, fear (β = .218, p < .001), response efficacy (β = .175, p < .01) and self-efficacy (β = .251, p < .001) were all significant predictors of intention to engage in social distancing behaviour. Overall, the PMT variables (and demographic factors) explain 21.2% of the variance in intention. The findings demonstrated that PMT was a useful framework for understanding intention to engage in social distancing behaviour, but not actual behaviour during the simulated epidemic. These findings may reflect an intention-behaviour gap in relation to social distancing behaviour.

Simulating Social Networks of Online Communities: Simulation as a Method for Sociability Design

Science.gov (United States)

Ang, Chee Siang; Zaphiris, Panayiotis

We propose the use of social simulations to study and support the design of online communities. In this paper, we developed an Agent-Based Model (ABM) to simulate and study the formation of social networks in a Massively Multiplayer Online Role Playing Game (MMORPG) guild community. We first analyzed the activities and the social network (who-interacts-with-whom) of an existing guild community to identify its interaction patterns and characteristics. Then, based on the empirical results, we derived and formalized the interaction rules, which were implemented in our simulation. Using the simulation, we reproduced the observed social network of the guild community as a means of validation. The simulation was then used to examine how various parameters of the community (e.g. the level of activity, the number of neighbors of each agent, etc) could potentially influence the characteristic of the social networks.

Computational simulation of concurrent engineering for aerospace propulsion systems

Science.gov (United States)

Chamis, C. C.; Singhal, S. N.

1992-01-01

Results are summarized of an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulations methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties - fundamental in developing such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering for propulsion systems and systems in general. Benefits and facets needing early attention in the development are outlined.

Computational simulation for concurrent engineering of aerospace propulsion systems

Science.gov (United States)

Chamis, C. C.; Singhal, S. N.

1993-01-01

Results are summarized for an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulation methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties--fundamental to develop such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering of propulsion systems and systems in general. Benefits and issues needing early attention in the development are outlined.

Computer-Based Simulation Games in Public Administration Education

OpenAIRE

Kutergina Evgeniia

2017-01-01

Computer simulation, an active learning technique, is now one of the advanced pedagogical technologies. Th e use of simulation games in the educational process allows students to gain a firsthand understanding of the processes of real life. Public- administration, public-policy and political-science courses increasingly adopt simulation games in universities worldwide. Besides person-to-person simulation games, there are computer-based simulations in public-administration education. Currently...

Inversion based on computational simulations

International Nuclear Information System (INIS)

Hanson, K.M.; Cunningham, G.S.; Saquib, S.S.

1998-01-01

A standard approach to solving inversion problems that involve many parameters uses gradient-based optimization to find the parameters that best match the data. The authors discuss enabling techniques that facilitate application of this approach to large-scale computational simulations, which are the only way to investigate many complex physical phenomena. Such simulations may not seem to lend themselves to calculation of the gradient with respect to numerous parameters. However, adjoint differentiation allows one to efficiently compute the gradient of an objective function with respect to all the variables of a simulation. When combined with advanced gradient-based optimization algorithms, adjoint differentiation permits one to solve very large problems of optimization or parameter estimation. These techniques will be illustrated through the simulation of the time-dependent diffusion of infrared light through tissue, which has been used to perform optical tomography. The techniques discussed have a wide range of applicability to modeling including the optimization of models to achieve a desired design goal

Computer-Based Simulation Games in Public Administration Education

Directory of Open Access Journals (Sweden)

Kutergina Evgeniia

2017-12-01

Full Text Available Computer simulation, an active learning technique, is now one of the advanced pedagogical technologies. Th e use of simulation games in the educational process allows students to gain a firsthand understanding of the processes of real life. Public- administration, public-policy and political-science courses increasingly adopt simulation games in universities worldwide. Besides person-to-person simulation games, there are computer-based simulations in public-administration education. Currently in Russia the use of computer-based simulation games in Master of Public Administration (MPA curricula is quite limited. Th is paper focuses on computer- based simulation games for students of MPA programmes. Our aim was to analyze outcomes of implementing such games in MPA curricula. We have done so by (1 developing three computer-based simulation games about allocating public finances, (2 testing the games in the learning process, and (3 conducting a posttest examination to evaluate the effect of simulation games on students’ knowledge of municipal finances. Th is study was conducted in the National Research University Higher School of Economics (HSE and in the Russian Presidential Academy of National Economy and Public Administration (RANEPA during the period of September to December 2015, in Saint Petersburg, Russia. Two groups of students were randomly selected in each university and then randomly allocated either to the experimental or the control group. In control groups (n=12 in HSE, n=13 in RANEPA students had traditional lectures. In experimental groups (n=12 in HSE, n=13 in RANEPA students played three simulation games apart from traditional lectures. Th is exploratory research shows that the use of computer-based simulation games in MPA curricula can improve students’ outcomes by 38 %. In general, the experimental groups had better performances on the post-test examination (Figure 2. Students in the HSE experimental group had 27.5 % better

The Australian Computational Earth Systems Simulator

Science.gov (United States)

Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.

2001-12-01

Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic

Software Engineering for Scientific Computer Simulations

Science.gov (United States)

Post, Douglass E.; Henderson, Dale B.; Kendall, Richard P.; Whitney, Earl M.

2004-11-01

Computer simulation is becoming a very powerful tool for analyzing and predicting the performance of fusion experiments. Simulation efforts are evolving from including only a few effects to many effects, from small teams with a few people to large teams, and from workstations and small processor count parallel computers to massively parallel platforms. Successfully making this transition requires attention to software engineering issues. We report on the conclusions drawn from a number of case studies of large scale scientific computing projects within DOE, academia and the DoD. The major lessons learned include attention to sound project management including setting reasonable and achievable requirements, building a good code team, enforcing customer focus, carrying out verification and validation and selecting the optimum computational mathematics approaches.

Automatic temperature computation for realistic IR simulation

Science.gov (United States)

Le Goff, Alain; Kersaudy, Philippe; Latger, Jean; Cathala, Thierry; Stolte, Nilo; Barillot, Philippe

2000-07-01

Polygon temperature computation in 3D virtual scenes is fundamental for IR image simulation. This article describes in detail the temperature calculation software and its current extensions, briefly presented in [1]. This software, called MURET, is used by the simulation workshop CHORALE of the French DGA. MURET is a one-dimensional thermal software, which accurately takes into account the material thermal attributes of three-dimensional scene and the variation of the environment characteristics (atmosphere) as a function of the time. Concerning the environment, absorbed incident fluxes are computed wavelength by wavelength, for each half an hour, druing 24 hours before the time of the simulation. For each polygon, incident fluxes are compsed of: direct solar fluxes, sky illumination (including diffuse solar fluxes). Concerning the materials, classical thermal attributes are associated to several layers, such as conductivity, absorption, spectral emissivity, density, specific heat, thickness and convection coefficients are taken into account. In the future, MURET will be able to simulate permeable natural materials (water influence) and vegetation natural materials (woods). This model of thermal attributes induces a very accurate polygon temperature computation for the complex 3D databases often found in CHORALE simulations. The kernel of MUET consists of an efficient ray tracer allowing to compute the history (over 24 hours) of the shadowed parts of the 3D scene and a library, responsible for the thermal computations. The great originality concerns the way the heating fluxes are computed. Using ray tracing, the flux received in each 3D point of the scene accurately takes into account the masking (hidden surfaces) between objects. By the way, this library supplies other thermal modules such as a thermal shows computation tool.

Adapting computational text analysis to social science (and vice versa

Directory of Open Access Journals (Sweden)

Paul DiMaggio

2015-11-01

Full Text Available Social scientists and computer scientist are divided by small differences in perspective and not by any significant disciplinary divide. In the field of text analysis, several such differences are noted: social scientists often use unsupervised models to explore corpora, whereas many computer scientists employ supervised models to train data; social scientists hold to more conventional causal notions than do most computer scientists, and often favor intense exploitation of existing algorithms, whereas computer scientists focus more on developing new models; and computer scientists tend to trust human judgment more than social scientists do. These differences have implications that potentially can improve the practice of social science.

Discrete Event Simulation Computers can be used to simulate the ...

Indian Academy of Sciences (India)

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people who use computers every moment of their waking lives, others even ... How is discrete event simulation different from other kinds of simulation? ... time, energy consumption .... Schedule the CustomerDeparture event for this customer.

Information-Theoretic Approaches for Evaluating Complex Adaptive Social Simulation Systems

Energy Technology Data Exchange (ETDEWEB)

Omitaomu, Olufemi A [ORNL; Ganguly, Auroop R [ORNL; Jiao, Yu [ORNL

2009-01-01

In this paper, we propose information-theoretic approaches for comparing and evaluating complex agent-based models. In information theoretic terms, entropy and mutual information are two measures of system complexity. We used entropy as a measure of the regularity of the number of agents in a social class; and mutual information as a measure of information shared by two social classes. Using our approaches, we compared two analogous agent-based (AB) models developed for regional-scale social-simulation system. The first AB model, called ABM-1, is a complex AB built with 10,000 agents on a desktop environment and used aggregate data; the second AB model, ABM-2, was built with 31 million agents on a highperformance computing framework located at Oak Ridge National Laboratory, and fine-resolution data from the LandScan Global Population Database. The initializations were slightly different, with ABM-1 using samples from a probability distribution and ABM-2 using polling data from Gallop for a deterministic initialization. The geographical and temporal domain was present-day Afghanistan, and the end result was the number of agents with one of three behavioral modes (proinsurgent, neutral, and pro-government) corresponding to the population mindshare. The theories embedded in each model were identical, and the test simulations focused on a test of three leadership theories - legitimacy, coercion, and representative, and two social mobilization theories - social influence and repression. The theories are tied together using the Cobb-Douglas utility function. Based on our results, the hypothesis that performance measures can be developed to compare and contrast AB models appears to be supported. Furthermore, we observed significant bias in the two models. Even so, further tests and investigations are required not only with a wider class of theories and AB models, but also with additional observed or simulated data and more comprehensive performance measures.

Launch Site Computer Simulation and its Application to Processes

Science.gov (United States)

Sham, Michael D.

1995-01-01

This paper provides an overview of computer simulation, the Lockheed developed STS Processing Model, and the application of computer simulation to a wide range of processes. The STS Processing Model is an icon driven model that uses commercial off the shelf software and a Macintosh personal computer. While it usually takes one year to process and launch 8 space shuttles, with the STS Processing Model this process is computer simulated in about 5 minutes. Facilities, orbiters, or ground support equipment can be added or deleted and the impact on launch rate, facility utilization, or other factors measured as desired. This same computer simulation technology can be used to simulate manufacturing, engineering, commercial, or business processes. The technology does not require an 'army' of software engineers to develop and operate, but instead can be used by the layman with only a minimal amount of training. Instead of making changes to a process and realizing the results after the fact, with computer simulation, changes can be made and processes perfected before they are implemented.

Quantum chemistry simulation on quantum computers: theories and experiments.

Science.gov (United States)

Lu, Dawei; Xu, Boruo; Xu, Nanyang; Li, Zhaokai; Chen, Hongwei; Peng, Xinhua; Xu, Ruixue; Du, Jiangfeng

2012-07-14

It has been claimed that quantum computers can mimic quantum systems efficiently in the polynomial scale. Traditionally, those simulations are carried out numerically on classical computers, which are inevitably confronted with the exponential growth of required resources, with the increasing size of quantum systems. Quantum computers avoid this problem, and thus provide a possible solution for large quantum systems. In this paper, we first discuss the ideas of quantum simulation, the background of quantum simulators, their categories, and the development in both theories and experiments. We then present a brief introduction to quantum chemistry evaluated via classical computers followed by typical procedures of quantum simulation towards quantum chemistry. Reviewed are not only theoretical proposals but also proof-of-principle experimental implementations, via a small quantum computer, which include the evaluation of the static molecular eigenenergy and the simulation of chemical reaction dynamics. Although the experimental development is still behind the theory, we give prospects and suggestions for future experiments. We anticipate that in the near future quantum simulation will become a powerful tool for quantum chemistry over classical computations.

Parameterized algorithmics for computational social choice : nine research challenges

NARCIS (Netherlands)

Bredereck, R.; Chen, J.; Faliszewski, P.; Guo, J.; Niedermeier, R.; Woeginger, G.J.

2014-01-01

Computational Social Choice is an interdisciplinary research area involving Economics, Political Science, and Social Science on the one side, and Mathematics and Computer Science (including Artificial Intelligence and Multiagent Systems) on the other side. Typical computational problems studied in

The role of computer simulation in nuclear technologies development

International Nuclear Information System (INIS)

Tikhonchev, M.Yu.; Shimansky, G.A.; Lebedeva, E.E.; Lichadeev, V. V.; Ryazanov, D.K.; Tellin, A.I.

2001-01-01

In the report the role and purposes of computer simulation in nuclear technologies development is discussed. The authors consider such applications of computer simulation as nuclear safety researches, optimization of technical and economic parameters of acting nuclear plant, planning and support of reactor experiments, research and design new devices and technologies, design and development of 'simulators' for operating personnel training. Among marked applications the following aspects of computer simulation are discussed in the report: neutron-physical, thermal and hydrodynamics models, simulation of isotope structure change and damage dose accumulation for materials under irradiation, simulation of reactor control structures. (authors)

Computational steering of GEM based detector simulations

Science.gov (United States)

Sheharyar, Ali; Bouhali, Othmane

2017-10-01

Gas based detector R&D relies heavily on full simulation of detectors and their optimization before final prototypes can be built and tested. These simulations in particular those with complex scenarios such as those involving high detector voltages or gas with larger gains are computationally intensive may take several days or weeks to complete. These long-running simulations usually run on the high-performance computers in batch mode. If the results lead to unexpected behavior, then the simulation might be rerun with different parameters. However, the simulations (or jobs) may have to wait in a queue until they get a chance to run again because the supercomputer is a shared resource that maintains a queue of other user programs as well and executes them as time and priorities permit. It may result in inefficient resource utilization and increase in the turnaround time for the scientific experiment. To overcome this issue, the monitoring of the behavior of a simulation, while it is running (or live), is essential. In this work, we employ the computational steering technique by coupling the detector simulations with a visualization package named VisIt to enable the exploration of the live data as it is produced by the simulation.

Highway traffic simulation on multi-processor computers

Energy Technology Data Exchange (ETDEWEB)

Hanebutte, U.R.; Doss, E.; Tentner, A.M.

1997-04-01

A computer model has been developed to simulate highway traffic for various degrees of automation with a high level of fidelity in regard to driver control and vehicle characteristics. The model simulates vehicle maneuvering in a multi-lane highway traffic system and allows for the use of Intelligent Transportation System (ITS) technologies such as an Automated Intelligent Cruise Control (AICC). The structure of the computer model facilitates the use of parallel computers for the highway traffic simulation, since domain decomposition techniques can be applied in a straight forward fashion. In this model, the highway system (i.e. a network of road links) is divided into multiple regions; each region is controlled by a separate link manager residing on an individual processor. A graphical user interface augments the computer model kv allowing for real-time interactive simulation control and interaction with each individual vehicle and road side infrastructure element on each link. Average speed and traffic volume data is collected at user-specified loop detector locations. Further, as a measure of safety the so- called Time To Collision (TTC) parameter is being recorded.

Alternative energy technologies an introduction with computer simulations

CERN Document Server

Buxton, Gavin

2014-01-01

Introduction to Alternative Energy SourcesGlobal WarmingPollutionSolar CellsWind PowerBiofuelsHydrogen Production and Fuel CellsIntroduction to Computer ModelingBrief History of Computer SimulationsMotivation and Applications of Computer ModelsUsing Spreadsheets for SimulationsTyping Equations into SpreadsheetsFunctions Available in SpreadsheetsRandom NumbersPlotting DataMacros and ScriptsInterpolation and ExtrapolationNumerical Integration and Diffe

Large-scale computing techniques for complex system simulations

CERN Document Server

Dubitzky, Werner; Schott, Bernard

2012-01-01

Complex systems modeling and simulation approaches are being adopted in a growing number of sectors, including finance, economics, biology, astronomy, and many more. Technologies ranging from distributed computing to specialized hardware are explored and developed to address the computational requirements arising in complex systems simulations. The aim of this book is to present a representative overview of contemporary large-scale computing technologies in the context of complex systems simulations applications. The intention is to identify new research directions in this field and

The role of computer simulation in nuclear technology development

International Nuclear Information System (INIS)

Tikhonchev, M.Yu.; Shimansky, G.A.; Lebedeva, E.E.; Lichadeev, VV.; Ryazanov, D.K.; Tellin, A.I.

2000-01-01

In the report, the role and purpose of computer simulation in nuclear technology development is discussed. The authors consider such applications of computer simulation as: (a) Nuclear safety research; (b) Optimization of technical and economic parameters of acting nuclear plant; (c) Planning and support of reactor experiments; (d) Research and design new devices and technologies; (f) Design and development of 'simulators' for operating personnel training. Among marked applications, the following aspects of computer simulation are discussed in the report: (g) Neutron-physical, thermal and hydrodynamics models; (h) Simulation of isotope structure change and dam- age dose accumulation for materials under irradiation; (i) Simulation of reactor control structures. (authors)

Development of computational science in JAEA. R and D of simulation

International Nuclear Information System (INIS)

Nakajima, Norihiro; Araya, Fumimasa; Hirayama, Toshio

2006-01-01

R and D of computational science in JAEA (Japan Atomic Energy Agency) is described. Environment of computer, R and D system in CCSE (Center for Computational Science and e-Systems), joint computational science researches in Japan and world, development of computer technologies, the some examples of simulation researches, 3-dimensional image vibrational platform system, simulation researches of FBR cycle techniques, simulation of large scale thermal stress for development of steam generator, simulation research of fusion energy techniques, development of grid computing technology, simulation research of quantum beam techniques and biological molecule simulation researches are explained. Organization of JAEA, development of computational science in JAEA, network of JAEA, international collaboration of computational science, and environment of ITBL (Information-Technology Based Laboratory) project are illustrated. (S.Y.)

Polymer Composites Corrosive Degradation: A Computational Simulation

Science.gov (United States)

Chamis, Christos C.; Minnetyan, Levon

2007-01-01

A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

Social things : design research on social computing

NARCIS (Netherlands)

Hu, J.; Luen, P.; Rau, P.

2016-01-01

In the era of social networking and computing, things and people are more and more interconnected, giving rise to not only new opportunities but also new challenges in designing new products that are networked, and services that are adaptive to their human users and context aware in their physical

An integrated computational tool for precipitation simulation

Science.gov (United States)

Cao, W.; Zhang, F.; Chen, S.-L.; Zhang, C.; Chang, Y. A.

2011-07-01

Computer aided materials design is of increasing interest because the conventional approach solely relying on experimentation is no longer viable within the constraint of available resources. Modeling of microstructure and mechanical properties during precipitation plays a critical role in understanding the behavior of materials and thus accelerating the development of materials. Nevertheless, an integrated computational tool coupling reliable thermodynamic calculation, kinetic simulation, and property prediction of multi-component systems for industrial applications is rarely available. In this regard, we are developing a software package, PanPrecipitation, under the framework of integrated computational materials engineering to simulate precipitation kinetics. It is seamlessly integrated with the thermodynamic calculation engine, PanEngine, to obtain accurate thermodynamic properties and atomic mobility data necessary for precipitation simulation.

Estimating social carrying capacity through computer simulation modeling: an application to Arches National Park, Utah

Science.gov (United States)

Benjamin Wang; Robert E. Manning; Steven R. Lawson; William A. Valliere

2001-01-01

Recent research and management experience has led to several frameworks for defining and managing carrying capacity of national parks and related areas. These frameworks rely on monitoring indicator variables to ensure that standards of quality are maintained. The objective of this study was to develop a computer simulation model to estimate the relationships between...

The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

Energy Technology Data Exchange (ETDEWEB)

Chen, Y W [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Zhang, L F [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Huang, J P [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China)

2007-07-20

By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property.

The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

International Nuclear Information System (INIS)

Chen, Y W; Zhang, L F; Huang, J P

2007-01-01

By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property

Fluid simulation for computer graphics

CERN Document Server

Bridson, Robert

2008-01-01

Animating fluids like water, smoke, and fire using physics-based simulation is increasingly important in visual effects, in particular in movies, like The Day After Tomorrow, and in computer games. This book provides a practical introduction to fluid simulation for graphics. The focus is on animating fully three-dimensional incompressible flow, from understanding the math and the algorithms to the actual implementation.

Large-scale simulations of error-prone quantum computation devices

International Nuclear Information System (INIS)

Trieu, Doan Binh

2009-01-01

The theoretical concepts of quantum computation in the idealized and undisturbed case are well understood. However, in practice, all quantum computation devices do suffer from decoherence effects as well as from operational imprecisions. This work assesses the power of error-prone quantum computation devices using large-scale numerical simulations on parallel supercomputers. We present the Juelich Massively Parallel Ideal Quantum Computer Simulator (JUMPIQCS), that simulates a generic quantum computer on gate level. It comprises an error model for decoherence and operational errors. The robustness of various algorithms in the presence of noise has been analyzed. The simulation results show that for large system sizes and long computations it is imperative to actively correct errors by means of quantum error correction. We implemented the 5-, 7-, and 9-qubit quantum error correction codes. Our simulations confirm that using error-prone correction circuits with non-fault-tolerant quantum error correction will always fail, because more errors are introduced than being corrected. Fault-tolerant methods can overcome this problem, provided that the single qubit error rate is below a certain threshold. We incorporated fault-tolerant quantum error correction techniques into JUMPIQCS using Steane's 7-qubit code and determined this threshold numerically. Using the depolarizing channel as the source of decoherence, we find a threshold error rate of (5.2±0.2) x 10 -6 . For Gaussian distributed operational over-rotations the threshold lies at a standard deviation of 0.0431±0.0002. We can conclude that quantum error correction is especially well suited for the correction of operational imprecisions and systematic over-rotations. For realistic simulations of specific quantum computation devices we need to extend the generic model to dynamic simulations, i.e. time-dependent Hamiltonian simulations of realistic hardware models. We focus on today's most advanced technology, i

Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

Science.gov (United States)

Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

2010-10-01

Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Sophistication of computational science and fundamental physics simulations

International Nuclear Information System (INIS)

Ishiguro, Seiji; Ito, Atsushi; Usami, Shunsuke; Ohtani, Hiroaki; Sakagami, Hitoshi; Toida, Mieko; Hasegawa, Hiroki; Horiuchi, Ritoku; Miura, Hideaki

2016-01-01

Numerical experimental reactor research project is composed of the following studies: (1) nuclear fusion simulation research with a focus on specific physical phenomena of specific equipment, (2) research on advanced simulation method to increase predictability or expand its application range based on simulation, (3) visualization as the foundation of simulation research, (4) research for advanced computational science such as parallel computing technology, and (5) research aiming at elucidation of fundamental physical phenomena not limited to specific devices. Specifically, a wide range of researches with medium- to long-term perspectives are being developed: (1) virtual reality visualization, (2) upgrading of computational science such as multilayer simulation method, (3) kinetic behavior of plasma blob, (4) extended MHD theory and simulation, (5) basic plasma process such as particle acceleration due to interaction of wave and particle, and (6) research related to laser plasma fusion. This paper reviews the following items: (1) simultaneous visualization in virtual reality space, (2) multilayer simulation of collisionless magnetic reconnection, (3) simulation of microscopic dynamics of plasma coherent structure, (4) Hall MHD simulation of LHD, (5) numerical analysis for extension of MHD equilibrium and stability theory, (6) extended MHD simulation of 2D RT instability, (7) simulation of laser plasma, (8) simulation of shock wave and particle acceleration, and (9) study on simulation of homogeneous isotropic MHD turbulent flow. (A.O.)

Computer Simulation Performed for Columbia Project Cooling System

Science.gov (United States)

Ahmad, Jasim

2005-01-01

This demo shows a high-fidelity simulation of the air flow in the main computer room housing the Columbia (10,024 intel titanium processors) system. The simulation asseses the performance of the cooling system and identified deficiencies, and recommended modifications to eliminate them. It used two in house software packages on NAS supercomputers: Chimera Grid tools to generate a geometric model of the computer room, OVERFLOW-2 code for fluid and thermal simulation. This state-of-the-art technology can be easily extended to provide a general capability for air flow analyses on any modern computer room. Columbia_CFD_black.tiff

A Review of Freely Available Quantum Computer Simulation Software

OpenAIRE

Brandhorst-Satzkorn, Johan

2012-01-01

A study has been made of a few different freely available Quantum Computer simulators. All the simulators tested are available online on their respective websites. A number of tests have been performed to compare the different simulators against each other. Some untested simulators of various programming languages are included to show the diversity of the quantum computer simulator applications. The conclusion of the review is that LibQuantum is the best of the simulators tested because of ea...

Computer simulation of liquid crystals

International Nuclear Information System (INIS)

McBride, C.

1999-01-01

Molecular dynamics simulation performed on modern computer workstations provides a powerful tool for the investigation of the static and dynamic characteristics of liquid crystal phases. In this thesis molecular dynamics computer simulations have been performed for two model systems. Simulations of 4,4'-di-n-pentyl-bibicyclo[2.2.2]octane demonstrate the growth of a structurally ordered phase directly from an isotropic fluid. This is the first time that this has been achieved for an atomistic model. The results demonstrate a strong coupling between orientational ordering and molecular shape, but indicate that the coupling between molecular conformational changes and molecular reorientation is relatively weak. Simulations have also been performed for a hybrid Gay-Berne/Lennard-Jones model resulting in thermodynamically stable nematic and smectic phases. Frank elastic constants have been calculated for the nematic phase formed by the hybrid model through analysis of the fluctuations of the nematic director, giving results comparable with those found experimentally. Work presented in this thesis also describes the parameterization of the torsional potential of a fragment of a dimethyl siloxane polymer chain, disiloxane diol (HOMe 2 Si) 2 O, using ab initio quantum mechanical calculations. (author)

Biomes computed from simulated climatologies

Energy Technology Data Exchange (ETDEWEB)

Claussen, M.; Esch, M. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

1994-01-01

The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting chances in vegetation patterns due to a rapid climate change, the latter simulation to be taken as a prediction of chances in conditions favourable for the existence of certain biomes, not as a reduction of a future distribution of biomes. 15 refs., 8 figs., 2 tabs.

Computational substrates of social value in interpersonal collaboration.

Science.gov (United States)

Fareri, Dominic S; Chang, Luke J; Delgado, Mauricio R

2015-05-27

Decisions to engage in collaborative interactions require enduring considerable risk, yet provide the foundation for building and maintaining relationships. Here, we investigate the mechanisms underlying this process and test a computational model of social value to predict collaborative decision making. Twenty-six participants played an iterated trust game and chose to invest more frequently with their friends compared with a confederate or computer despite equal reinforcement rates. This behavior was predicted by our model, which posits that people receive a social value reward signal from reciprocation of collaborative decisions conditional on the closeness of the relationship. This social value signal was associated with increased activity in the ventral striatum and medial prefrontal cortex, which significantly predicted the reward parameters from the social value model. Therefore, we demonstrate that the computation of social value drives collaborative behavior in repeated interactions and provide a mechanistic account of reward circuit function instantiating this process. Copyright © 2015 the authors 0270-6474/15/358170-11$15.00/0.

Computer security simulation

International Nuclear Information System (INIS)

Schelonka, E.P.

1979-01-01

Development and application of a series of simulation codes used for computer security analysis and design are described. Boolean relationships for arrays of barriers within functional modules are used to generate composite effectiveness indices. The general case of multiple layers of protection with any specified barrier survival criteria is given. Generalized reduction algorithms provide numerical security indices in selected subcategories and for the system as a whole. 9 figures, 11 tables

Overview of Computer Simulation Modeling Approaches and Methods

Science.gov (United States)

Robert E. Manning; Robert M. Itami; David N. Cole; Randy Gimblett

2005-01-01

The field of simulation modeling has grown greatly with recent advances in computer hardware and software. Much of this work has involved large scientific and industrial applications for which substantial financial resources are available. However, advances in object-oriented programming and simulation methodology, concurrent with dramatic increases in computer...

REACTOR: a computer simulation for schools

International Nuclear Information System (INIS)

Squires, D.

1985-01-01

The paper concerns computer simulation of the operation of a nuclear reactor, for use in schools. The project was commissioned by UKAEA, and carried out by the Computers in the Curriculum Project, Chelsea College. The program, for an advanced gas cooled reactor, is briefly described. (U.K.)

A roadmap to computational social neuroscience.

Science.gov (United States)

Tognoli, Emmanuelle; Dumas, Guillaume; Kelso, J A Scott

2018-02-01

To complement experimental efforts toward understanding human social interactions at both neural and behavioral levels, two computational approaches are presented: (1) a fully parameterizable mathematical model of a social partner, the Human Dynamic Clamp which, by virtue of experimentally controlled interactions between Virtual Partners and real people, allows for emergent behaviors to be studied; and (2) a multiscale neurocomputational model of social coordination that enables exploration of social self-organization at all levels-from neuronal patterns to people interacting with each other. These complementary frameworks and the cross product of their analysis aim at understanding the fundamental principles governing social behavior.

Learning and instruction with computer simulations

NARCIS (Netherlands)

de Jong, Anthonius J.M.

1991-01-01

The present volume presents the results of an inventory of elements of such a computer learning environment. This inventory was conducted within a DELTA project called SIMULATE. In the project a learning environment that provides intelligent support to learners and that has a simulation as its

Computer simulation on molten ionic salts

International Nuclear Information System (INIS)

Kawamura, K.; Okada, I.

1978-01-01

The extensive advances in computer technology have since made it possible to apply computer simulation to the evaluation of the macroscopic and microscopic properties of molten salts. The evaluation of the potential energy in molten salts systems is complicated by the presence of long-range energy, i.e. Coulomb energy, in contrast to simple liquids where the potential energy is easily evaluated. It has been shown, however, that no difficulties are encountered when the Ewald method is applied to the evaluation of Coulomb energy. After a number of attempts had been made to approximate the pair potential, the Huggins-Mayer potential based on ionic crystals became the most often employed. Since it is thought that the only appreciable contribution to many-body potential, not included in Huggins-Mayer potential, arises from the internal electrostatic polarization of ions in molten ionic salts, computer simulation with a provision for ion polarization has been tried recently. The computations, which are employed mainly for molten alkali halides, can provide: (1) thermodynamic data such as internal energy, internal pressure and isothermal compressibility; (2) microscopic configurational data such as radial distribution functions; (3) transport data such as the diffusion coefficient and electrical conductivity; and (4) spectroscopic data such as the intensity of inelastic scattering and the stretching frequency of simple molecules. The computed results seem to agree well with the measured results. Computer simulation can also be used to test the effectiveness of a proposed pair potential and the adequacy of postulated models of molten salts, and to obtain experimentally inaccessible data. A further application of MD computation employing the pair potential based on an ionic model to BeF 2 , ZnCl 2 and SiO 2 shows the possibility of quantitative interpretation of structures and glass transformation phenomena

New Pedagogies on Teaching Science with Computer Simulations

Science.gov (United States)

Khan, Samia

2011-01-01

Teaching science with computer simulations is a complex undertaking. This case study examines how an experienced science teacher taught chemistry using computer simulations and the impact of his teaching on his students. Classroom observations over 3 semesters, teacher interviews, and student surveys were collected. The data was analyzed for (1)…

Large-scale simulations of error-prone quantum computation devices

Energy Technology Data Exchange (ETDEWEB)

Trieu, Doan Binh

2009-07-01

The theoretical concepts of quantum computation in the idealized and undisturbed case are well understood. However, in practice, all quantum computation devices do suffer from decoherence effects as well as from operational imprecisions. This work assesses the power of error-prone quantum computation devices using large-scale numerical simulations on parallel supercomputers. We present the Juelich Massively Parallel Ideal Quantum Computer Simulator (JUMPIQCS), that simulates a generic quantum computer on gate level. It comprises an error model for decoherence and operational errors. The robustness of various algorithms in the presence of noise has been analyzed. The simulation results show that for large system sizes and long computations it is imperative to actively correct errors by means of quantum error correction. We implemented the 5-, 7-, and 9-qubit quantum error correction codes. Our simulations confirm that using error-prone correction circuits with non-fault-tolerant quantum error correction will always fail, because more errors are introduced than being corrected. Fault-tolerant methods can overcome this problem, provided that the single qubit error rate is below a certain threshold. We incorporated fault-tolerant quantum error correction techniques into JUMPIQCS using Steane's 7-qubit code and determined this threshold numerically. Using the depolarizing channel as the source of decoherence, we find a threshold error rate of (5.2{+-}0.2) x 10{sup -6}. For Gaussian distributed operational over-rotations the threshold lies at a standard deviation of 0.0431{+-}0.0002. We can conclude that quantum error correction is especially well suited for the correction of operational imprecisions and systematic over-rotations. For realistic simulations of specific quantum computation devices we need to extend the generic model to dynamic simulations, i.e. time-dependent Hamiltonian simulations of realistic hardware models. We focus on today's most advanced

Toward an Ontology of Simulated Social Interaction

DEFF Research Database (Denmark)

Seibt, Johanna

2017-01-01

and asymmetric modes of realizing Á, called the ‘simulatory expansion’ of interaction type Á. Simulatory expansions of social interactions can be used to map out different kinds and degrees of sociality in human-human and human-robot interaction, relative to current notions of sociality in philosophy......, anthropology, and linguistics. The classificatory framework developed (SISI) thus represents the field of possible simulated social interactions. SISI can be used to clarify which conceptual and empirical grounds we can draw on to evaluate capacities and affordances of robots for social interaction......The paper develops a general conceptual framework for the ontological classification of human-robot interaction. After arguing against fictionalist interpretations of human-robot interactions, I present five notions of simulation or partial realization, formally defined in terms of relationships...

Interoceanic canal excavation scheduling via computer simulation

Energy Technology Data Exchange (ETDEWEB)

Baldonado, Orlino C [Holmes and Narver, Inc., Los Angeles, CA (United States)

1970-05-15

The computer simulation language GPSS/360 was used to simulate the schedule of several nuclear detonation programs for the interoceanic canal project. The effects of using different weather restriction categories due to air blast and fallout were investigated. The effect of increasing the number of emplacement and stemming crews and the effect of varying the reentry period after detonating a row charge or salvo were also studied. Detonation programs were simulated for the proposed Routes 17A and 25E. The study demonstrates the method of using computer simulation so that a schedule and its associated constraints can be assessed for feasibility. Since many simulation runs can be made for a given set of detonation program constraints, one readily obtains an average schedule for a range of conditions. This provides a method for analyzing time-sensitive operations so that time and cost-effective operational schedules can be established. A comparison of the simulated schedules with those that were published shows them to be similar. (author)

Interoceanic canal excavation scheduling via computer simulation

International Nuclear Information System (INIS)

Baldonado, Orlino C.

1970-01-01

The computer simulation language GPSS/360 was used to simulate the schedule of several nuclear detonation programs for the interoceanic canal project. The effects of using different weather restriction categories due to air blast and fallout were investigated. The effect of increasing the number of emplacement and stemming crews and the effect of varying the reentry period after detonating a row charge or salvo were also studied. Detonation programs were simulated for the proposed Routes 17A and 25E. The study demonstrates the method of using computer simulation so that a schedule and its associated constraints can be assessed for feasibility. Since many simulation runs can be made for a given set of detonation program constraints, one readily obtains an average schedule for a range of conditions. This provides a method for analyzing time-sensitive operations so that time and cost-effective operational schedules can be established. A comparison of the simulated schedules with those that were published shows them to be similar. (author)

Biomes computed from simulated climatologies

Energy Technology Data Exchange (ETDEWEB)

Claussen, W.; Esch, M.

1992-09-01

The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study is undertaken in order to show the advantage of this biome model in comprehensively diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to failures in simulated rain fall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are seen for the tropical rain forests. A potential North-East shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting changes in vegetation patterns due to a rapid climate change, the latter simulation has to be taken as a prediction of changes in conditions favorable for the existence of certain biomes, not as a prediction of a future distribution of biomes. (orig.).

Computer graphics in heat-transfer simulations

International Nuclear Information System (INIS)

Hamlin, G.A. Jr.

1980-01-01

Computer graphics can be very useful in the setup of heat transfer simulations and in the display of the results of such simulations. The potential use of recently available low-cost graphics devices in the setup of such simulations has not been fully exploited. Several types of graphics devices and their potential usefulness are discussed, and some configurations of graphics equipment are presented in the low-, medium-, and high-price ranges

Parallel Computing for Brain Simulation.

Science.gov (United States)

Pastur-Romay, L A; Porto-Pazos, A B; Cedron, F; Pazos, A

2017-01-01

The human brain is the most complex system in the known universe, it is therefore one of the greatest mysteries. It provides human beings with extraordinary abilities. However, until now it has not been understood yet how and why most of these abilities are produced. For decades, researchers have been trying to make computers reproduce these abilities, focusing on both understanding the nervous system and, on processing data in a more efficient way than before. Their aim is to make computers process information similarly to the brain. Important technological developments and vast multidisciplinary projects have allowed creating the first simulation with a number of neurons similar to that of a human brain. This paper presents an up-to-date review about the main research projects that are trying to simulate and/or emulate the human brain. They employ different types of computational models using parallel computing: digital models, analog models and hybrid models. This review includes the current applications of these works, as well as future trends. It is focused on various works that look for advanced progress in Neuroscience and still others which seek new discoveries in Computer Science (neuromorphic hardware, machine learning techniques). Their most outstanding characteristics are summarized and the latest advances and future plans are presented. In addition, this review points out the importance of considering not only neurons: Computational models of the brain should also include glial cells, given the proven importance of astrocytes in information processing. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Computational Dehydration of Crystalline Hydrates Using Molecular Dynamics Simulations

DEFF Research Database (Denmark)

Larsen, Anders Støttrup; Rantanen, Jukka; Johansson, Kristoffer E

2017-01-01

Molecular dynamics (MD) simulations have evolved to an increasingly reliable and accessible technique and are today implemented in many areas of biomedical sciences. We present a generally applicable method to study dehydration of hydrates based on MD simulations and apply this approach...... to the dehydration of ampicillin trihydrate. The crystallographic unit cell of the trihydrate is used to construct the simulation cell containing 216 ampicillin and 648 water molecules. This system is dehydrated by removing water molecules during a 2200 ps simulation, and depending on the computational dehydration....... The structural changes could be followed in real time, and in addition, an intermediate amorphous phase was identified. The computationally identified dehydrated structure (anhydrate) was slightly different from the experimentally known anhydrate structure suggesting that the simulated computational structure...

9th Conference of the European Social Simulation Association

CERN Document Server

Koloch, Grzegorz

2014-01-01

This book is the conference proceedings of ESSA 2013, the 9th Conference of the European Social Simulation Association. ESSA conferences constitute annual events which serve as an international platform for the exchange of ideas and discussion of cutting-edge research in the field of social simulations, both from the theoretical as well as applied perspective. This book consists of 33 articles, which are divided into four themes: Methods for the development of simulation models, Applications of agent-based modeling, Adaptive behavior, social interactions and global environmental change and Using qualitative data to inform behavioral rules. We are convinced that this book will serve interested readers as a useful compendium which presents in a nutshell the most recent advances at the frontiers of social simulation research.

Computer simulation of thermal plant operations

CERN Document Server

O'Kelly, Peter

2012-01-01

This book describes thermal plant simulation, that is, dynamic simulation of plants which produce, exchange and otherwise utilize heat as their working medium. Directed at chemical, mechanical and control engineers involved with operations, control and optimization and operator training, the book gives the mathematical formulation and use of simulation models of the equipment and systems typically found in these industries. The author has adopted a fundamental approach to the subject. The initial chapters provide an overview of simulation concepts and describe a suitable computer environment.

Developing Cognitive Models for Social Simulation from Survey Data

Science.gov (United States)

Alt, Jonathan K.; Lieberman, Stephen

The representation of human behavior and cognition continues to challenge the modeling and simulation community. The use of survey and polling instruments to inform belief states, issue stances and action choice models provides a compelling means of developing models and simulations with empirical data. Using these types of data to population social simulations can greatly enhance the feasibility of validation efforts, the reusability of social and behavioral modeling frameworks, and the testable reliability of simulations. We provide a case study demonstrating these effects, document the use of survey data to develop cognitive models, and suggest future paths forward for social and behavioral modeling.

A Computer-Based Simulation of an Acid-Base Titration

Science.gov (United States)

Boblick, John M.

1971-01-01

Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

Social networks a framework of computational intelligence

CERN Document Server

Chen, Shyi-Ming

2014-01-01

This volume provides the audience with an updated, in-depth and highly coherent material on the conceptually appealing and practically sound information technology of Computational Intelligence applied to the analysis, synthesis and evaluation of social networks. The volume involves studies devoted to key issues of social networks including community structure detection in networks, online social networks, knowledge growth and evaluation, and diversity of collaboration mechanisms.  The book engages a wealth of methods of Computational Intelligence along with well-known techniques of linear programming, Formal Concept Analysis, machine learning, and agent modeling.  Human-centricity is of paramount relevance and this facet manifests in many ways including personalized semantics, trust metric, and personal knowledge management; just to highlight a few of these aspects. The contributors to this volume report on various essential applications including cyber attacks detection, building enterprise social network...

Quantum simulations with noisy quantum computers

Science.gov (United States)

Gambetta, Jay

Quantum computing is a new computational paradigm that is expected to lie beyond the standard model of computation. This implies a quantum computer can solve problems that can't be solved by a conventional computer with tractable overhead. To fully harness this power we need a universal fault-tolerant quantum computer. However the overhead in building such a machine is high and a full solution appears to be many years away. Nevertheless, we believe that we can build machines in the near term that cannot be emulated by a conventional computer. It is then interesting to ask what these can be used for. In this talk we will present our advances in simulating complex quantum systems with noisy quantum computers. We will show experimental implementations of this on some small quantum computers.

Salesperson Ethics: An Interactive Computer Simulation

Science.gov (United States)

Castleberry, Stephen

2014-01-01

A new interactive computer simulation designed to teach sales ethics is described. Simulation learner objectives include gaining a better understanding of legal issues in selling; realizing that ethical dilemmas do arise in selling; realizing the need to be honest when selling; seeing that there are conflicting demands from a salesperson's…

Simulations of Probabilities for Quantum Computing

Science.gov (United States)

Zak, M.

1996-01-01

It has been demonstrated that classical probabilities, and in particular, probabilistic Turing machine, can be simulated by combining chaos and non-LIpschitz dynamics, without utilization of any man-made devices (such as random number generators). Self-organizing properties of systems coupling simulated and calculated probabilities and their link to quantum computations are discussed.

Social computing for verifying social media content in breaking news

OpenAIRE

Middleton, Stuart; Papadopoulos, Symeon; Kompatsiaris, Yiannis

2018-01-01

Social media is the place to go for both journalists and the general public when news events break, offering a real-time source of eyewitness images and videos through platforms like YouTube, Instagram, and Periscope. Yet, the value of such content as a means of documenting and disseminating breaking news is compromised by the increasing amount of content misuse and false claims in social media. To this end, cost-effective social computing solutions for user-generated content verification are...

Fluid Centrality: A Social Network Analysis of Social-Technical Relations in Computer-Mediated Communication

Science.gov (United States)

Enriquez, Judith Guevarra

2010-01-01

In this article, centrality is explored as a measure of computer-mediated communication (CMC) in networked learning. Centrality measure is quite common in performing social network analysis (SNA) and in analysing social cohesion, strength of ties and influence in CMC, and computer-supported collaborative learning research. It argues that measuring…

Benefits of computer screen-based simulation in learning cardiac arrest procedures.

Science.gov (United States)

Bonnetain, Elodie; Boucheix, Jean-Michel; Hamet, Maël; Freysz, Marc

2010-07-01

What is the best way to train medical students early so that they acquire basic skills in cardiopulmonary resuscitation as effectively as possible? Studies have shown the benefits of high-fidelity patient simulators, but have also demonstrated their limits. New computer screen-based multimedia simulators have fewer constraints than high-fidelity patient simulators. In this area, as yet, there has been no research on the effectiveness of transfer of learning from a computer screen-based simulator to more realistic situations such as those encountered with high-fidelity patient simulators. We tested the benefits of learning cardiac arrest procedures using a multimedia computer screen-based simulator in 28 Year 2 medical students. Just before the end of the traditional resuscitation course, we compared two groups. An experiment group (EG) was first asked to learn to perform the appropriate procedures in a cardiac arrest scenario (CA1) in the computer screen-based learning environment and was then tested on a high-fidelity patient simulator in another cardiac arrest simulation (CA2). While the EG was learning to perform CA1 procedures in the computer screen-based learning environment, a control group (CG) actively continued to learn cardiac arrest procedures using practical exercises in a traditional class environment. Both groups were given the same amount of practice, exercises and trials. The CG was then also tested on the high-fidelity patient simulator for CA2, after which it was asked to perform CA1 using the computer screen-based simulator. Performances with both simulators were scored on a precise 23-point scale. On the test on a high-fidelity patient simulator, the EG trained with a multimedia computer screen-based simulator performed significantly better than the CG trained with traditional exercises and practice (16.21 versus 11.13 of 23 possible points, respectively; p<0.001). Computer screen-based simulation appears to be effective in preparing learners to

Agent Based Modelling for Social Simulation

NARCIS (Netherlands)

Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

2013-01-01

This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course

Computer Simulation of Reading.

Science.gov (United States)

Leton, Donald A.

In recent years, coding and decoding have been claimed to be the processes for converting one language form to another. But there has been little effort to locate these processes in the human learner or to identify the nature of the internal codes. Computer simulation of reading is useful because the similarities in the human reception and…

Evaluation of Computer Simulations for Teaching Apparel Merchandising Concepts.

Science.gov (United States)

Jolly, Laura D.; Sisler, Grovalynn

1988-01-01

The study developed and evaluated computer simulations for teaching apparel merchandising concepts. Evaluation results indicated that teaching method (computer simulation versus case study) does not significantly affect cognitive learning. Student attitudes varied, however, according to topic (profitable merchandising analysis versus retailing…

Methodology of modeling and measuring computer architectures for plasma simulations

Science.gov (United States)

Wang, L. P. T.

1977-01-01

A brief introduction to plasma simulation using computers and the difficulties on currently available computers is given. Through the use of an analyzing and measuring methodology - SARA, the control flow and data flow of a particle simulation model REM2-1/2D are exemplified. After recursive refinements the total execution time may be greatly shortened and a fully parallel data flow can be obtained. From this data flow, a matched computer architecture or organization could be configured to achieve the computation bound of an application problem. A sequential type simulation model, an array/pipeline type simulation model, and a fully parallel simulation model of a code REM2-1/2D are proposed and analyzed. This methodology can be applied to other application problems which have implicitly parallel nature.

Computer Simulation of a Hardwood Processing Plant

Science.gov (United States)

D. Earl Kline; Philip A. Araman

1990-01-01

The overall purpose of this paper is to introduce computer simulation as a decision support tool that can be used to provide managers with timely information. A simulation/animation modeling procedure is demonstrated for wood products manufacuring systems. Simulation modeling techniques are used to assist in identifying and solving problems. Animation is used for...

Interferences and events on epistemic shifts in physics through computer simulations

CERN Document Server

Warnke, Martin

2017-01-01

Computer simulations are omnipresent media in today's knowledge production. For scientific endeavors such as the detection of gravitational waves and the exploration of subatomic worlds, simulations are essential; however, the epistemic status of computer simulations is rather controversial as they are neither just theory nor just experiment. Therefore, computer simulations have challenged well-established insights and common scientific practices as well as our very understanding of knowledge. This volume contributes to the ongoing discussion on the epistemic position of computer simulations in a variety of physical disciplines, such as quantum optics, quantum mechanics, and computational physics. Originating from an interdisciplinary event, it shows that accounts of contemporary physics can constructively interfere with media theory, philosophy, and the history of science.

Fair Secure Computation with Reputation Assumptions in the Mobile Social Networks

Directory of Open Access Journals (Sweden)

Yilei Wang

2015-01-01

Full Text Available With the rapid development of mobile devices and wireless technologies, mobile social networks become increasingly available. People can implement many applications on the basis of mobile social networks. Secure computation, like exchanging information and file sharing, is one of such applications. Fairness in secure computation, which means that either all parties implement the application or none of them does, is deemed as an impossible task in traditional secure computation without mobile social networks. Here we regard the applications in mobile social networks as specific functions and stress on the achievement of fairness on these functions within mobile social networks in the presence of two rational parties. Rational parties value their utilities when they participate in secure computation protocol in mobile social networks. Therefore, we introduce reputation derived from mobile social networks into the utility definition such that rational parties have incentives to implement the applications for a higher utility. To the best of our knowledge, the protocol is the first fair secure computation in mobile social networks. Furthermore, it finishes within constant rounds and allows both parties to know the terminal round.

Computed radiography simulation using the Monte Carlo code MCNPX

International Nuclear Information System (INIS)

Correa, S.C.A.; Souza, E.M.; Silva, A.X.; Lopes, R.T.

2009-01-01

Simulating x-ray images has been of great interest in recent years as it makes possible an analysis of how x-ray images are affected owing to relevant operating parameters. In this paper, a procedure for simulating computed radiographic images using the Monte Carlo code MCNPX is proposed. The sensitivity curve of the BaFBr image plate detector as well as the characteristic noise of a 16-bit computed radiography system were considered during the methodology's development. The results obtained confirm that the proposed procedure for simulating computed radiographic images is satisfactory, as it allows obtaining results comparable with experimental data. (author)

Computed radiography simulation using the Monte Carlo code MCNPX

Energy Technology Data Exchange (ETDEWEB)

Correa, S.C.A. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Centro Universitario Estadual da Zona Oeste (CCMAT)/UEZO, Av. Manuel Caldeira de Alvarenga, 1203, Campo Grande, 23070-200, Rio de Janeiro, RJ (Brazil); Souza, E.M. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Silva, A.X., E-mail: ademir@con.ufrj.b [PEN/COPPE-DNC/Poli CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Cassiano, D.H. [Instituto de Radioprotecao e Dosimetria/CNEN Av. Salvador Allende, s/n, Recreio, 22780-160, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil)

2010-09-15

Simulating X-ray images has been of great interest in recent years as it makes possible an analysis of how X-ray images are affected owing to relevant operating parameters. In this paper, a procedure for simulating computed radiographic images using the Monte Carlo code MCNPX is proposed. The sensitivity curve of the BaFBr image plate detector as well as the characteristic noise of a 16-bit computed radiography system were considered during the methodology's development. The results obtained confirm that the proposed procedure for simulating computed radiographic images is satisfactory, as it allows obtaining results comparable with experimental data.

Proceedings of the meeting on large scale computer simulation research

International Nuclear Information System (INIS)

2004-04-01

The meeting to summarize the collaboration activities for FY2003 on the Large Scale Computer Simulation Research was held January 15-16, 2004 at Theory and Computer Simulation Research Center, National Institute for Fusion Science. Recent simulation results, methodologies and other related topics were presented. (author)

Computational simulation in architectural and environmental acoustics methods and applications of wave-based computation

CERN Document Server

Sakamoto, Shinichi; Otsuru, Toru

2014-01-01

This book reviews a variety of methods for wave-based acoustic simulation and recent applications to architectural and environmental acoustic problems. Following an introduction providing an overview of computational simulation of sound environment, the book is in two parts: four chapters on methods and four chapters on applications. The first part explains the fundamentals and advanced techniques for three popular methods, namely, the finite-difference time-domain method, the finite element method, and the boundary element method, as well as alternative time-domain methods. The second part demonstrates various applications to room acoustics simulation, noise propagation simulation, acoustic property simulation for building components, and auralization. This book is a valuable reference that covers the state of the art in computational simulation for architectural and environmental acoustics.  

A computer code to simulate X-ray imaging techniques

International Nuclear Information System (INIS)

Duvauchelle, Philippe; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

2000-01-01

A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests

A computer code to simulate X-ray imaging techniques

Energy Technology Data Exchange (ETDEWEB)

Duvauchelle, Philippe E-mail: philippe.duvauchelle@insa-lyon.fr; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

2000-09-01

A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests.

Inovation of the computer system for the WWER-440 simulator

International Nuclear Information System (INIS)

Schrumpf, L.

1988-01-01

The configuration of the WWER-440 simulator computer system consists of four SMEP computers. The basic data processing unit consists of two interlinked SM 52/11.M1 computers with 1 MB of main memory. This part of the computer system of the simulator controls the operation of the entire simulator, processes the programs of technology behavior simulation, of the unit information system and of other special systems, guarantees program support and the operation of the instructor's console. An SM 52/11 computer with 256 kB of main memory is connected to each unit. It is used as a communication unit for data transmission using the DASIO 600 interface. Semigraphic color displays are based on the microprocessor modules of the SM 50/40 and SM 53/10 kit supplemented with a modified TESLA COLOR 110 ST tv receiver. (J.B.). 1 fig

Computer Based Modelling and Simulation

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 3. Computer Based Modelling and Simulation - Modelling Deterministic Systems. N K Srinivasan. General Article Volume 6 Issue 3 March 2001 pp 46-54. Fulltext. Click here to view fulltext PDF. Permanent link:

Computer Simulation (Microcultures): An Effective Model for Multicultural Education.

Science.gov (United States)

Nelson, Jorge O.

This paper presents a rationale for using high-fidelity computer simulation in planning for and implementing effective multicultural education strategies. Using computer simulation, educators can begin to understand and plan for the concept of cultural sensitivity in delivering instruction. The model promises to emphasize teachers' understanding…

Computer simulation in cell radiobiology

International Nuclear Information System (INIS)

Yakovlev, A.Y.; Zorin, A.V.

1988-01-01

This research monograph demonstrates the possible ways of using stochastic simulation for exploring cell kinetics, emphasizing the effects of cell radiobiology. In vitro kinetics of normal and irradiated cells is the main subject, but some approaches to the simulation of controlled cell systems are considered as well: the epithelium of the small intestine in mice taken as a case in point. Of particular interest is the evaluation of simulation modelling as a tool for gaining insight into biological processes and hence the new inferences from concrete experimental data, concerning regularities in cell population response to irradiation. The book is intended to stimulate interest among computer science specialists in developing new, more efficient means for the simulation of cell systems and to help radiobiologists in interpreting the experimental data

Tutorial: Parallel Computing of Simulation Models for Risk Analysis.

Science.gov (United States)

Reilly, Allison C; Staid, Andrea; Gao, Michael; Guikema, Seth D

2016-10-01

Simulation models are widely used in risk analysis to study the effects of uncertainties on outcomes of interest in complex problems. Often, these models are computationally complex and time consuming to run. This latter point may be at odds with time-sensitive evaluations or may limit the number of parameters that are considered. In this article, we give an introductory tutorial focused on parallelizing simulation code to better leverage modern computing hardware, enabling risk analysts to better utilize simulation-based methods for quantifying uncertainty in practice. This article is aimed primarily at risk analysts who use simulation methods but do not yet utilize parallelization to decrease the computational burden of these models. The discussion is focused on conceptual aspects of embarrassingly parallel computer code and software considerations. Two complementary examples are shown using the languages MATLAB and R. A brief discussion of hardware considerations is located in the Appendix. © 2016 Society for Risk Analysis.

Computer simulation of human motion in sports biomechanics.

Science.gov (United States)

Vaughan, C L

1984-01-01

This chapter has covered some important aspects of the computer simulation of human motion in sports biomechanics. First the definition and the advantages and limitations of computer simulation were discussed; second, research on various sporting activities were reviewed. These activities included basic movements, aquatic sports, track and field athletics, winter sports, gymnastics, and striking sports. This list was not exhaustive and certain material has, of necessity, been omitted. However, it was felt that a sufficiently broad and interesting range of activities was chosen to illustrate both the advantages and the pitfalls of simulation. It is almost a decade since Miller [53] wrote a review chapter similar to this one. One might be tempted to say that things have changed radically since then--that computer simulation is now a widely accepted and readily applied research tool in sports biomechanics. This is simply not true, however. Biomechanics researchers still tend to emphasize the descriptive type of study, often unfortunately, when a little theoretical explanation would have been more helpful [29]. What will the next decade bring? Of one thing we can be certain: The power of computers, particularly the readily accessible and portable microcomputer, will expand beyond all recognition. The memory and storage capacities will increase dramatically on the hardware side, and on the software side the trend will be toward "user-friendliness." It is likely that a number of software simulation packages designed specifically for studying human motion [31, 96] will be extensively tested and could gain wide acceptance in the biomechanics research community. Nevertheless, a familiarity with Newtonian and Lagrangian mechanics, optimization theory, and computers in general, as well as practical biomechanical insight, will still be a prerequisite for successful simulation models of human motion. Above all, the biomechanics researcher will still have to bear in mind that

Simulation of biological ion channels with technology computer-aided design.

Science.gov (United States)

Pandey, Santosh; Bortei-Doku, Akwete; White, Marvin H

2007-01-01

Computer simulations of realistic ion channel structures have always been challenging and a subject of rigorous study. Simulations based on continuum electrostatics have proven to be computationally cheap and reasonably accurate in predicting a channel's behavior. In this paper we discuss the use of a device simulator, SILVACO, to build a solid-state model for KcsA channel and study its steady-state response. SILVACO is a well-established program, typically used by electrical engineers to simulate the process flow and electrical characteristics of solid-state devices. By employing this simulation program, we have presented an alternative computing platform for performing ion channel simulations, besides the known methods of writing codes in programming languages. With the ease of varying the different parameters in the channel's vestibule and the ability of incorporating surface charges, we have shown the wide-ranging possibilities of using a device simulator for ion channel simulations. Our simulated results closely agree with the experimental data, validating our model.

Computational algorithms for simulations in atmospheric optics.

Science.gov (United States)

Konyaev, P A; Lukin, V P

2016-04-20

A computer simulation technique for atmospheric and adaptive optics based on parallel programing is discussed. A parallel propagation algorithm is designed and a modified spectral-phase method for computer generation of 2D time-variant random fields is developed. Temporal power spectra of Laguerre-Gaussian beam fluctuations are considered as an example to illustrate the applications discussed. Implementation of the proposed algorithms using Intel MKL and IPP libraries and NVIDIA CUDA technology is shown to be very fast and accurate. The hardware system for the computer simulation is an off-the-shelf desktop with an Intel Core i7-4790K CPU operating at a turbo-speed frequency up to 5 GHz and an NVIDIA GeForce GTX-960 graphics accelerator with 1024 1.5 GHz processors.

R&D for computational cognitive and social models : foundations for model evaluation through verification and validation (final LDRD report).

Energy Technology Data Exchange (ETDEWEB)

Slepoy, Alexander; Mitchell, Scott A.; Backus, George A.; McNamara, Laura A.; Trucano, Timothy Guy

2008-09-01

Sandia National Laboratories is investing in projects that aim to develop computational modeling and simulation applications that explore human cognitive and social phenomena. While some of these modeling and simulation projects are explicitly research oriented, others are intended to support or provide insight for people involved in high consequence decision-making. This raises the issue of how to evaluate computational modeling and simulation applications in both research and applied settings where human behavior is the focus of the model: when is a simulation 'good enough' for the goals its designers want to achieve? In this report, we discuss two years' worth of review and assessment of the ASC program's approach to computational model verification and validation, uncertainty quantification, and decision making. We present a framework that extends the principles of the ASC approach into the area of computational social and cognitive modeling and simulation. In doing so, we argue that the potential for evaluation is a function of how the modeling and simulation software will be used in a particular setting. In making this argument, we move from strict, engineering and physics oriented approaches to V&V to a broader project of model evaluation, which asserts that the systematic, rigorous, and transparent accumulation of evidence about a model's performance under conditions of uncertainty is a reasonable and necessary goal for model evaluation, regardless of discipline. How to achieve the accumulation of evidence in areas outside physics and engineering is a significant research challenge, but one that requires addressing as modeling and simulation tools move out of research laboratories and into the hands of decision makers. This report provides an assessment of our thinking on ASC Verification and Validation, and argues for further extending V&V research in the physical and engineering sciences toward a broader program of model

SiMon: Simulation Monitor for Computational Astrophysics

Science.gov (United States)

Xuran Qian, Penny; Cai, Maxwell Xu; Portegies Zwart, Simon; Zhu, Ming

2017-09-01

Scientific discovery via numerical simulations is important in modern astrophysics. This relatively new branch of astrophysics has become possible due to the development of reliable numerical algorithms and the high performance of modern computing technologies. These enable the analysis of large collections of observational data and the acquisition of new data via simulations at unprecedented accuracy and resolution. Ideally, simulations run until they reach some pre-determined termination condition, but often other factors cause extensive numerical approaches to break down at an earlier stage. In those cases, processes tend to be interrupted due to unexpected events in the software or the hardware. In those cases, the scientist handles the interrupt manually, which is time-consuming and prone to errors. We present the Simulation Monitor (SiMon) to automatize the farming of large and extensive simulation processes. Our method is light-weight, it fully automates the entire workflow management, operates concurrently across multiple platforms and can be installed in user space. Inspired by the process of crop farming, we perceive each simulation as a crop in the field and running simulation becomes analogous to growing crops. With the development of SiMon we relax the technical aspects of simulation management. The initial package was developed for extensive parameter searchers in numerical simulations, but it turns out to work equally well for automating the computational processing and reduction of observational data reduction.

Computer Simulation of Diffraction Patterns.

Science.gov (United States)

Dodd, N. A.

1983-01-01

Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

Social Play at the Computer: Preschoolers Scaffold and Support Peers' Computer Competence.

Science.gov (United States)

Freeman, Nancy K.; Somerindyke, Jennifer

2001-01-01

Describes preschoolers' collaboration during free play in a computer lab, focusing on the computer's contribution to active, peer-mediated learning. Discusses these observations in terms of Parten's insights on children's social play and Vygotsky's socio-cultural learning theory, noting that the children scaffolded each other's growing computer…

[Animal experimentation, computer simulation and surgical research].

Science.gov (United States)

Carpentier, Alain

2009-11-01

We live in a digital world In medicine, computers are providing new tools for data collection, imaging, and treatment. During research and development of complex technologies and devices such as artificial hearts, computer simulation can provide more reliable information than experimentation on large animals. In these specific settings, animal experimentation should serve more to validate computer models of complex devices than to demonstrate their reliability.

CPU SIM: A Computer Simulator for Use in an Introductory Computer Organization-Architecture Class.

Science.gov (United States)

Skrein, Dale

1994-01-01

CPU SIM, an interactive low-level computer simulation package that runs on the Macintosh computer, is described. The program is designed for instructional use in the first or second year of undergraduate computer science, to teach various features of typical computer organization through hands-on exercises. (MSE)

A Computational Framework for Efficient Low Temperature Plasma Simulations

Science.gov (United States)

Verma, Abhishek Kumar; Venkattraman, Ayyaswamy

2016-10-01

Over the past years, scientific computing has emerged as an essential tool for the investigation and prediction of low temperature plasmas (LTP) applications which includes electronics, nanomaterial synthesis, metamaterials etc. To further explore the LTP behavior with greater fidelity, we present a computational toolbox developed to perform LTP simulations. This framework will allow us to enhance our understanding of multiscale plasma phenomenon using high performance computing tools mainly based on OpenFOAM FVM distribution. Although aimed at microplasma simulations, the modular framework is able to perform multiscale, multiphysics simulations of physical systems comprises of LTP. Some salient introductory features are capability to perform parallel, 3D simulations of LTP applications on unstructured meshes. Performance of the solver is tested based on numerical results assessing accuracy and efficiency of benchmarks for problems in microdischarge devices. Numerical simulation of microplasma reactor at atmospheric pressure with hemispherical dielectric coated electrodes will be discussed and hence, provide an overview of applicability and future scope of this framework.

Use of computer graphics simulation for teaching of flexible sigmoidoscopy.

Science.gov (United States)

Baillie, J; Jowell, P; Evangelou, H; Bickel, W; Cotton, P

1991-05-01

The concept of simulation training in endoscopy is now well-established. The systems currently under development employ either computer graphics simulation or interactive video technology; each has its strengths and weaknesses. A flexible sigmoidoscopy training device has been designed which uses graphic routines--such as object oriented programming and double buffering--in entirely new ways. These programming techniques compensate for the limitations of currently available desk-top microcomputers. By boosting existing computer 'horsepower' with next generation coprocessors and sophisticated graphics tools such as intensity interpolation (Gouraud shading), the realism of computer simulation of flexible sigmoidoscopy is being greatly enhanced. The computer program has teaching and scoring capabilities, making it a truly interactive system. Use has been made of this ability to record, grade and store each trainee encounter in computer memory as part of a multi-center, prospective trial of simulation training being conducted currently in the USA. A new input device, a dummy endoscope, has been designed that allows application of variable resistance to the insertion tube. This greatly enhances tactile feedback, such as resistance during looping. If carefully designed trials show that computer simulation is an attractive and effective training tool, it is expected that this technology will evolve rapidly and be made widely available to trainee endoscopists.

Effect of computer game playing on baseline laparoscopic simulator skills.

Science.gov (United States)

Halvorsen, Fredrik H; Cvancarova, Milada; Fosse, Erik; Mjåland, Odd

2013-08-01

Studies examining the possible association between computer game playing and laparoscopic performance in general have yielded conflicting results and neither has a relationship between computer game playing and baseline performance on laparoscopic simulators been established. The aim of this study was to examine the possible association between previous and present computer game playing and baseline performance on a virtual reality laparoscopic performance in a sample of potential future medical students. The participating students completed a questionnaire covering the weekly amount and type of computer game playing activity during the previous year and 3 years ago. They then performed 2 repetitions of 2 tasks ("gallbladder dissection" and "traverse tube") on a virtual reality laparoscopic simulator. Performance on the simulator were then analyzed for association to their computer game experience. Local high school, Norway. Forty-eight students from 2 high school classes volunteered to participate in the study. No association between prior and present computer game playing and baseline performance was found. The results were similar both for prior and present action game playing and prior and present computer game playing in general. Our results indicate that prior and present computer game playing may not affect baseline performance in a virtual reality simulator.

Noise simulation in cone beam CT imaging with parallel computing

International Nuclear Information System (INIS)

Tu, S.-J.; Shaw, Chris C; Chen, Lingyun

2006-01-01

We developed a computer noise simulation model for cone beam computed tomography imaging using a general purpose PC cluster. This model uses a mono-energetic x-ray approximation and allows us to investigate three primary performance components, specifically quantum noise, detector blurring and additive system noise. A parallel random number generator based on the Weyl sequence was implemented in the noise simulation and a visualization technique was accordingly developed to validate the quality of the parallel random number generator. In our computer simulation model, three-dimensional (3D) phantoms were mathematically modelled and used to create 450 analytical projections, which were then sampled into digital image data. Quantum noise was simulated and added to the analytical projection image data, which were then filtered to incorporate flat panel detector blurring. Additive system noise was generated and added to form the final projection images. The Feldkamp algorithm was implemented and used to reconstruct the 3D images of the phantoms. A 24 dual-Xeon PC cluster was used to compute the projections and reconstructed images in parallel with each CPU processing 10 projection views for a total of 450 views. Based on this computer simulation system, simulated cone beam CT images were generated for various phantoms and technique settings. Noise power spectra for the flat panel x-ray detector and reconstructed images were then computed to characterize the noise properties. As an example among the potential applications of our noise simulation model, we showed that images of low contrast objects can be produced and used for image quality evaluation

The Simulation and Analysis of the Closed Die Hot Forging Process by A Computer Simulation Method

Directory of Open Access Journals (Sweden)

Dipakkumar Gohil

2012-06-01

Full Text Available The objective of this research work is to study the variation of various parameters such as stress, strain, temperature, force, etc. during the closed die hot forging process. A computer simulation modeling approach has been adopted to transform the theoretical aspects in to a computer algorithm which would be used to simulate and analyze the closed die hot forging process. For the purpose of process study, the entire deformation process has been divided in to finite number of steps appropriately and then the output values have been computed at each deformation step. The results of simulation have been graphically represented and suitable corrective measures are also recommended, if the simulation results do not agree with the theoretical values. This computer simulation approach would significantly improve the productivity and reduce the energy consumption of the overall process for the components which are manufactured by the closed die forging process and contribute towards the efforts in reducing the global warming.

Prototyping and Simulating Parallel, Distributed Computations with VISA

National Research Council Canada - National Science Library

Demeure, Isabelle M; Nutt, Gary J

1989-01-01

...] to support the design, prototyping, and simulation of parallel, distributed computations. In particular, VISA is meant to guide the choice of partitioning and communication strategies for such computations, based on their performance...

Slab cooling system design using computer simulation

NARCIS (Netherlands)

Lain, M.; Zmrhal, V.; Drkal, F.; Hensen, J.L.M.

2007-01-01

For a new technical library building in Prague computer simulations were carried out to help design of slab cooling system and optimize capacity of chillers. In the paper is presented concept of new technical library HVAC system, the model of the building, results of the energy simulations for

Biocellion: accelerating computer simulation of multicellular biological system models.

Science.gov (United States)

Kang, Seunghwa; Kahan, Simon; McDermott, Jason; Flann, Nicholas; Shmulevich, Ilya

2014-11-01

Biological system behaviors are often the outcome of complex interactions among a large number of cells and their biotic and abiotic environment. Computational biologists attempt to understand, predict and manipulate biological system behavior through mathematical modeling and computer simulation. Discrete agent-based modeling (in combination with high-resolution grids to model the extracellular environment) is a popular approach for building biological system models. However, the computational complexity of this approach forces computational biologists to resort to coarser resolution approaches to simulate large biological systems. High-performance parallel computers have the potential to address the computing challenge, but writing efficient software for parallel computers is difficult and time-consuming. We have developed Biocellion, a high-performance software framework, to solve this computing challenge using parallel computers. To support a wide range of multicellular biological system models, Biocellion asks users to provide their model specifics by filling the function body of pre-defined model routines. Using Biocellion, modelers without parallel computing expertise can efficiently exploit parallel computers with less effort than writing sequential programs from scratch. We simulate cell sorting, microbial patterning and a bacterial system in soil aggregate as case studies. Biocellion runs on x86 compatible systems with the 64 bit Linux operating system and is freely available for academic use. Visit http://biocellion.com for additional information. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

How Many Times Should One Run a Computational Simulation?

DEFF Research Database (Denmark)

Seri, Raffaello; Secchi, Davide

2017-01-01

This chapter is an attempt to answer the question “how many runs of a computational simulation should one do,” and it gives an answer by means of statistical analysis. After defining the nature of the problem and which types of simulation are mostly affected by it, the article introduces statisti......This chapter is an attempt to answer the question “how many runs of a computational simulation should one do,” and it gives an answer by means of statistical analysis. After defining the nature of the problem and which types of simulation are mostly affected by it, the article introduces...

SOCIAL INSTITUTION OF EDUCATION AND COMPUTER VIRTUAL REALITY: POINTS OF INFLUENCE

OpenAIRE

Tarakanov Sergey Anatolevich

2012-01-01

This article discusses the impact of computer virtual reality to education as a social institution. Author gives a description of education as a social institution. Outlines the main changes of the institute of education under the influence of a virtual online-environment. Author makes the following conclusions: 1. Computer virtual reality expands sphere of activity of social institution of education. 2. Computer virtual reality deletes status and role differences. It influences on the system...

Comparing the social skills of students addicted to computer games with normal students.

Science.gov (United States)

Zamani, Eshrat; Kheradmand, Ali; Cheshmi, Maliheh; Abedi, Ahmad; Hedayati, Nasim

2010-01-01

This study aimed to investigate and compare the social skills of studentsaddicted to computer games with normal students. The dependentvariable in the present study is the social skills. The study population included all the students in the second grade ofpublic secondary school in the city of Isfahan at the educational year of2009-2010. The sample size included 564 students selected using thecluster random sampling method. Data collection was conducted usingQuestionnaire of Addiction to Computer Games and Social SkillsQuestionnaire (The Teenage Inventory of Social Skill or TISS). The results of the study showed that generally, there was a significantdifference between the social skills of students addicted to computer gamesand normal students. In addition, the results indicated that normal studentshad a higher level of social skills in comparison with students addicted tocomputer games. As the study results showed, addiction to computer games may affectthe quality and quantity of social skills. In other words, the higher theaddiction to computer games, the less the social skills. The individualsaddicted to computer games have less social skills.).

Computer simulation of gear tooth manufacturing processes

Science.gov (United States)

Mavriplis, Dimitri; Huston, Ronald L.

1990-01-01

The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

A Fast Synthetic Aperture Radar Raw Data Simulation Using Cloud Computing.

Science.gov (United States)

Li, Zhixin; Su, Dandan; Zhu, Haijiang; Li, Wei; Zhang, Fan; Li, Ruirui

2017-01-08

Synthetic Aperture Radar (SAR) raw data simulation is a fundamental problem in radar system design and imaging algorithm research. The growth of surveying swath and resolution results in a significant increase in data volume and simulation period, which can be considered to be a comprehensive data intensive and computing intensive issue. Although several high performance computing (HPC) methods have demonstrated their potential for accelerating simulation, the input/output (I/O) bottleneck of huge raw data has not been eased. In this paper, we propose a cloud computing based SAR raw data simulation algorithm, which employs the MapReduce model to accelerate the raw data computing and the Hadoop distributed file system (HDFS) for fast I/O access. The MapReduce model is designed for the irregular parallel accumulation of raw data simulation, which greatly reduces the parallel efficiency of graphics processing unit (GPU) based simulation methods. In addition, three kinds of optimization strategies are put forward from the aspects of programming model, HDFS configuration and scheduling. The experimental results show that the cloud computing based algorithm achieves 4_ speedup over the baseline serial approach in an 8-node cloud environment, and each optimization strategy can improve about 20%. This work proves that the proposed cloud algorithm is capable of solving the computing intensive and data intensive issues in SAR raw data simulation, and is easily extended to large scale computing to achieve higher acceleration.

The visual simulators for architecture and computer organization learning

OpenAIRE

Nikolić Boško; Grbanović Nenad; Đorđević Jovan

2009-01-01

The paper proposes a method of an effective distance learning of architecture and computer organization. The proposed method is based on a software system that is possible to be applied in any course in this field. Within this system students are enabled to observe simulation of already created computer systems. The system provides creation and simulation of switch systems, too.

Programme for the simulation of the TPA-i 1001 computer on the CDC-1604-A computer

International Nuclear Information System (INIS)

Belyaev, A.V.

1976-01-01

The basic features and capacities of the program simulating the 1001 TPA-i computer with the help of CDC-1604-A are described. The program is essentially aimed at translation of programs in the SLAHG language for the TPA-type computers. The basic part of the program simulates the work of the central TPA processor. This subprogram consequently performs the actions changing in the necessary manner the registers and memory states of the TPA computer. The simulated TPA computer has subprograms-analogous of external devices, i.e. the ASR-33 teletype, the FS 1501 tape reader, and the FACIT perforator. Work according to the program takes 1.65 - 2 times less time as against the work with TPA with the minimum set of external equipment [ru

Large scale particle simulations in a virtual memory computer

International Nuclear Information System (INIS)

Gray, P.C.; Million, R.; Wagner, J.S.; Tajima, T.

1983-01-01

Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceeds the computer core size. The required address space is automatically mapped onto slow disc memory the the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Assesses to slow memory significantly reduce the excecution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time. (orig.)

Large-scale particle simulations in a virtual-memory computer

International Nuclear Information System (INIS)

Gray, P.C.; Wagner, J.S.; Tajima, T.; Million, R.

1982-08-01

Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceed the computer core size. The required address space is automatically mapped onto slow disc memory by the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Accesses to slow memory significantly reduce the execution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time

Uses of Computer Simulation Models in Ag-Research and Everyday Life

Science.gov (United States)

When the news media talks about models they could be talking about role models, fashion models, conceptual models like the auto industry uses, or computer simulation models. A computer simulation model is a computer code that attempts to imitate the processes and functions of certain systems. There ...

Advanced Simulation and Computing FY17 Implementation Plan, Version 0

Energy Technology Data Exchange (ETDEWEB)

McCoy, Michel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Archer, Bill [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hendrickson, Bruce [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wade, Doug [National Nuclear Security Administration (NNSA), Washington, DC (United States). Office of Advanced Simulation and Computing and Institutional Research and Development; Hoang, Thuc [National Nuclear Security Administration (NNSA), Washington, DC (United States). Computational Systems and Software Environment

2016-08-29

The Stockpile Stewardship Program (SSP) is an integrated technical program for maintaining the safety, surety, and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational capabilities to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balance of resource, including technical staff, hardware, simulation software, and computer science solutions. ASC is now focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), and quantifying critical margins and uncertainties. Resolving each issue requires increasingly difficult analyses because the aging process has progressively moved the stockpile further away from the original test base. Where possible, the program also enables the use of high performance computing (HPC) and simulation tools to address broader national security needs, such as foreign nuclear weapon assessments and counter nuclear terrorism.

Using computer simulations to facilitate conceptual understanding of electromagnetic induction

Science.gov (United States)

Lee, Yu-Fen

This study investigated the use of computer simulations to facilitate conceptual understanding in physics. The use of computer simulations in the present study was grounded in a conceptual framework drawn from findings related to the use of computer simulations in physics education. To achieve the goal of effective utilization of computers for physics education, I first reviewed studies pertaining to computer simulations in physics education categorized by three different learning frameworks and studies comparing the effects of different simulation environments. My intent was to identify the learning context and factors for successful use of computer simulations in past studies and to learn from the studies which did not obtain a significant result. Based on the analysis of reviewed literature, I proposed effective approaches to integrate computer simulations in physics education. These approaches are consistent with well established education principles such as those suggested by How People Learn (Bransford, Brown, Cocking, Donovan, & Pellegrino, 2000). The research based approaches to integrated computer simulations in physics education form a learning framework called Concept Learning with Computer Simulations (CLCS) in the current study. The second component of this study was to examine the CLCS learning framework empirically. The participants were recruited from a public high school in Beijing, China. All participating students were randomly assigned to two groups, the experimental (CLCS) group and the control (TRAD) group. Research based computer simulations developed by the physics education research group at University of Colorado at Boulder were used to tackle common conceptual difficulties in learning electromagnetic induction. While interacting with computer simulations, CLCS students were asked to answer reflective questions designed to stimulate qualitative reasoning and explanation. After receiving model reasoning online, students were asked to submit

A Computer Simulation of Community Pharmacy Practice for Educational Use.

Science.gov (United States)

Bindoff, Ivan; Ling, Tristan; Bereznicki, Luke; Westbury, Juanita; Chalmers, Leanne; Peterson, Gregory; Ollington, Robert

2014-11-15

To provide a computer-based learning method for pharmacy practice that is as effective as paper-based scenarios, but more engaging and less labor-intensive. We developed a flexible and customizable computer simulation of community pharmacy. Using it, the students would be able to work through scenarios which encapsulate the entirety of a patient presentation. We compared the traditional paper-based teaching method to our computer-based approach using equivalent scenarios. The paper-based group had 2 tutors while the computer group had none. Both groups were given a prescenario and postscenario clinical knowledge quiz and survey. Students in the computer-based group had generally greater improvements in their clinical knowledge score, and third-year students using the computer-based method also showed more improvements in history taking and counseling competencies. Third-year students also found the simulation fun and engaging. Our simulation of community pharmacy provided an educational experience as effective as the paper-based alternative, despite the lack of a human tutor.

Combining integrated river modelling and agent based social simulation for river management; The case study of the Grensmaas project

NARCIS (Netherlands)

Valkering, P.; Krywkow, Jorg; Rotmans, J.; van der Veen, A.; Douben, N.; van Os, A.G.

2003-01-01

In this paper we present a coupled Integrated River Model – Agent Based Social Simulation model (IRM-ABSS) for river management. The models represent the case of the ongoing river engineering project “Grensmaas”. In the ABSS model stakeholders are represented as computer agents negotiating a river

Seventeenth Workshop on Computer Simulation Studies in Condensed-Matter Physics

CERN Document Server

Landau, David P; Schütler, Heinz-Bernd; Computer Simulation Studies in Condensed-Matter Physics XVI

2006-01-01

This status report features the most recent developments in the field, spanning a wide range of topical areas in the computer simulation of condensed matter/materials physics. Both established and new topics are included, ranging from the statistical mechanics of classical magnetic spin models to electronic structure calculations, quantum simulations, and simulations of soft condensed matter. The book presents new physical results as well as novel methods of simulation and data analysis. Highlights of this volume include various aspects of non-equilibrium statistical mechanics, studies of properties of real materials using both classical model simulations and electronic structure calculations, and the use of computer simulations in teaching.

Parallel Monte Carlo simulations on an ARC-enabled computing grid

International Nuclear Information System (INIS)

Nilsen, Jon K; Samset, Bjørn H

2011-01-01

Grid computing opens new possibilities for running heavy Monte Carlo simulations of physical systems in parallel. The presentation gives an overview of GaMPI, a system for running an MPI-based random walker simulation on grid resources. Integrating the ARC middleware and the new storage system Chelonia with the Ganga grid job submission and control system, we show that MPI jobs can be run on a world-wide computing grid with good performance and promising scaling properties. Results for relatively communication-heavy Monte Carlo simulations run on multiple heterogeneous, ARC-enabled computing clusters in several countries are presented.

Drill Sergeant or Math Teacher: Teacher Socialization and Computer Advertisements.

Science.gov (United States)

Gribble, Mary; And Others

This paper addresses the question of teacher socialization through contrived images, i.e., the influence of advertising as part of an educational and socialization process. It examines ways in which computer advertisements directed towards teachers influence their perceptions of how computers can and should be used, and how the same advertisements…

Computer simulation in nuclear science and engineering

International Nuclear Information System (INIS)

Akiyama, Mamoru; Miya, Kenzo; Iwata, Shuichi; Yagawa, Genki; Kondo, Shusuke; Hoshino, Tsutomu; Shimizu, Akinao; Takahashi, Hiroshi; Nakagawa, Masatoshi.

1992-01-01

The numerical simulation technology used for the design of nuclear reactors includes the scientific fields of wide range, and is the cultivated technology which grew in the steady efforts to high calculation accuracy through safety examination, reliability verification test, the assessment of operation results and so on. Taking the opportunity of putting numerical simulation to practical use in wide fields, the numerical simulation of five basic equations which describe the natural world and the progress of its related technologies are reviewed. It is expected that numerical simulation technology contributes to not only the means of design study but also the progress of science and technology such as the construction of new innovative concept, the exploration of new mechanisms and substances, of which the models do not exist in the natural world. The development of atomic energy and the progress of computers, Boltzmann's transport equation and its periphery, Navier-Stokes' equation and its periphery, Maxwell's electromagnetic field equation and its periphery, Schroedinger wave equation and its periphery, computational solid mechanics and its periphery, and probabilistic risk assessment and its periphery are described. (K.I.)

Computational fluid dynamics simulations of light water reactor flows

International Nuclear Information System (INIS)

Tzanos, C.P.; Weber, D.P.

1999-01-01

Advances in computational fluid dynamics (CFD), turbulence simulation, and parallel computing have made feasible the development of three-dimensional (3-D) single-phase and two-phase flow CFD codes that can simulate fluid flow and heat transfer in realistic reactor geometries with significantly reduced reliance, especially in single phase, on empirical correlations. The objective of this work was to assess the predictive power and computational efficiency of a CFD code in the analysis of a challenging single-phase light water reactor problem, as well as to identify areas where further improvements are needed

COMPUTER LEARNING SIMULATOR WITH VIRTUAL REALITY FOR OPHTHALMOLOGY

Directory of Open Access Journals (Sweden)

Valeria V. Gribova

2013-01-01

Full Text Available A toolset of a medical computer learning simulator for ophthalmology with virtual reality and its implementation are considered in the paper. The simulator is oriented for professional skills training for students of medical universities. 

Simulation in computer forensics teaching: the student experience

OpenAIRE

Crellin, Jonathan; Adda, Mo; Duke-Williams, Emma; Chandler, Jane

2011-01-01

The use of simulation in teaching computing is well established, with digital forensic investigation being a subject area where the range of simulation required is both wide and varied demanding a corresponding breadth of fidelity. Each type of simulation can be complex and expensive to set up resulting in students having only limited opportunities to participate and learn from the simulation. For example students' participation in mock trials in the University mock courtroom or in simulation...

The use of computer simulations in whole-class versus small-group settings

Science.gov (United States)

Smetana, Lara Kathleen

This study explored the use of computer simulations in a whole-class as compared to small-group setting. Specific consideration was given to the nature and impact of classroom conversations and interactions when computer simulations were incorporated into a high school chemistry course. This investigation fills a need for qualitative research that focuses on the social dimensions of actual classrooms. Participants included a novice chemistry teacher experienced in the use of educational technologies and two honors chemistry classes. The study was conducted in a rural school in the south-Atlantic United States at the end of the fall 2007 semester. The study took place during one instructional unit on atomic structure. Data collection allowed for triangulation of evidence from a variety of sources approximately 24 hours of video- and audio-taped classroom observations, supplemented with the researcher's field notes and analytic journal; miscellaneous classroom artifacts such as class notes, worksheets, and assignments; open-ended pre- and post-assessments; student exit interviews; teacher entrance, exit and informal interviews. Four web-based simulations were used, three of which were from the ExploreLearning collection. Assessments were analyzed using descriptive statistics and classroom observations, artifacts and interviews were analyzed using Erickson's (1986) guidelines for analytic induction. Conversational analysis was guided by methods outlined by Erickson (1982). Findings indicated (a) the teacher effectively incorporated simulations in both settings (b) students in both groups significantly improved their understanding of the chemistry concepts (c) there was no statistically significant difference between groups' achievement (d) there was more frequent exploratory talk in the whole-class group (e) there were more frequent and meaningful teacher-student interactions in the whole-class group (f) additional learning experiences not measured on the assessment

Molecular dynamics simulations and applications in computational toxicology and nanotoxicology.

Science.gov (United States)

Selvaraj, Chandrabose; Sakkiah, Sugunadevi; Tong, Weida; Hong, Huixiao

2018-02-01

Nanotoxicology studies toxicity of nanomaterials and has been widely applied in biomedical researches to explore toxicity of various biological systems. Investigating biological systems through in vivo and in vitro methods is expensive and time taking. Therefore, computational toxicology, a multi-discipline field that utilizes computational power and algorithms to examine toxicology of biological systems, has gained attractions to scientists. Molecular dynamics (MD) simulations of biomolecules such as proteins and DNA are popular for understanding of interactions between biological systems and chemicals in computational toxicology. In this paper, we review MD simulation methods, protocol for running MD simulations and their applications in studies of toxicity and nanotechnology. We also briefly summarize some popular software tools for execution of MD simulations. Published by Elsevier Ltd.

Computer simulation as representation of knowledge in education

International Nuclear Information System (INIS)

Krekic, Valerija Pinter; Namestovski, Zolt

2009-01-01

According to Aebli's operative method (1963) and Bruner's (1974) theory of representation the development of the process of thinking in teaching has the following phases - levels of abstraction: manipulation with specific things (specific phase), iconic representation (figural phase), symbolic representation (symbolic phase). Modern information technology has contributed to the enrichment of teaching and learning processes, especially in the fields of natural sciences and mathematics and those of production and technology. Simulation appears as a new possibility in the representation of knowledge. According to Guetzkow (1972) simulation is an operative representation of reality from a relevant aspect. It is about a model of an objective system, which is dynamic in itself. If that model is material it is a simple simulation, if it is abstract it is a reflective experiment, that is a computer simulation. This present work deals with the systematization and classification of simulation methods in the teaching of natural sciences and mathematics and of production and technology with special retrospective view on computer simulations and exemplar representation of the place and the role of this modern method of cognition. Key words: Representation of knowledge, modeling, simulation, education

Differences on the Level of Social Skills between Freshman Computer Gamers and Non-Gamers

Directory of Open Access Journals (Sweden)

Joseph B. Campit

2015-02-01

Full Text Available Computer games play a large role in socialization and the consequences of playing them have been a topic of debates. This observation led the researcher to conduct the study about the influence of computer games on the social skills of the BSIT first year students of Pangasinan State University, Bayambang Campus, during school year 2012-2013. This study determined the profile of the 115 BSIT first year students according to: preferred computer games and frequency of playing. It investigated the level of social skills among playing and non-playing gamers. This study used the descriptive-comparative method of research. It was found out that crossfire was the most preferred computer game played at least once a week. Computer gamers had lower social skills than non-computer gamers. Gamers have more negative social behaviors compared to non-gamers and there is a negative effect of playing computer games on the level of social skills among first year students. There is a significant difference in the level of social skills of the students when grouped according to frequency of playing computer games. Students who play computer games everyday had significantly lower social skills than who play once a week. Thus, parents and teachers should give proper guidance in the limitation of playing computer games and the choice of games. Teachers should organize seminars on the awareness of the influence and negative effects of violent computer games on social skills. And students should choose educational over violent games to enhance their knowledge and social skills.

Computer simulations of shear thickening of concentrated dispersions

NARCIS (Netherlands)

Boersma, W.H.; Laven, J.; Stein, H.N.

1995-01-01

Stokesian dynamics computer simulations were performed on monolayers of equally sized spheres. The influence of repulsive and attractive forces on the rheological behavior and on the microstructure were studied. Under specific conditions shear thickening could be observed in the simulations, usually

Computational fluid dynamics simulations and validations of results

CSIR Research Space (South Africa)

Sitek, MA

2013-09-01

Full Text Available Wind flow influence on a high-rise building is analyzed. The research covers full-scale tests, wind-tunnel experiments and numerical simulations. In the present paper computational model used in simulations is described and the results, which were...

Beat the Bourgeoisie: A Social Class Inequality and Mobility Simulation Game

Science.gov (United States)

Norris, Dawn R.

2013-01-01

Simulation games can help overcome student resistance to thinking structurally about social class inequality, meritocracy, and mobility. Most inequality simulations focus solely on economic inequality and omit social and cultural capital, both of which contribute to social class reproduction. Using a pretest/posttest design, the current study…

Computer Simulation of the Circulation Subsystem of a Library

Science.gov (United States)

Shaw, W. M., Jr.

1975-01-01

When circulation data are used as input parameters for a computer simulation of a library's circulation subsystem, the results of the simulation provide information on book availability and delays. The model may be used to simulate alternative loan policies. (Author/LS)

Using EDUCache Simulator for the Computer Architecture and Organization Course

Directory of Open Access Journals (Sweden)

Sasko Ristov

2013-07-01

Full Text Available The computer architecture and organization course is essential in all computer science and engineering programs, and the most selected and liked elective course for related engineering disciplines. However, the attractiveness brings a new challenge, it requires a lot of effort by the instructor, to explain rather complicated concepts to beginners or to those who study related disciplines. The usage of visual simulators can improve both the teaching and learning processes. The overall goal is twofold: 1~to enable a visual environment to explain the basic concepts and 2~to increase the student's willingness and ability to learn the material.A lot of visual simulators have been used for the computer architecture and organization course. However, due to the lack of visual simulators for simulation of the cache memory concepts, we have developed a new visual simulator EDUCache simulator. In this paper we present that it can be effectively and efficiently used as a supporting tool in the learning process of modern multi-layer, multi-cache and multi-core multi-processors.EDUCache's features enable an environment for performance evaluation and engineering of software systems, i.e. the students will also understand the importance of computer architecture building parts and hopefully, will increase their curiosity for hardware courses in general.

NeuroManager: A workflow analysis based simulation management engine for computational neuroscience

Directory of Open Access Journals (Sweden)

David Bruce Stockton

2015-10-01

Full Text Available We developed NeuroManager, an object-oriented simulation management software engine for computational neuroscience. NeuroManager automates the workflow of simulation job submissions when using heterogeneous computational resources, simulators, and simulation tasks. The object-oriented approach 1 provides flexibility to adapt to a variety of neuroscience simulators, 2 simplifies the use of heterogeneous computational resources, from desktops to super computer clusters, and 3 improves tracking of simulator/simulation evolution. We implemented NeuroManager in Matlab, a widely used engineering and scientific language, for its signal and image processing tools, prevalence in electrophysiology analysis, and increasing use in college Biology education. To design and develop NeuroManager we analyzed the workflow of simulation submission for a variety of simulators, operating systems, and computational resources, including the handling of input parameters, data, models, results, and analyses. This resulted in twenty-two stages of simulation submission workflow. The software incorporates progress notification, automatic organization, labeling, and time-stamping of data and results, and integrated access to Matlab's analysis and visualization tools. NeuroManager provides users with the tools to automate daily tasks, and assists principal investigators in tracking and recreating the evolution of research projects performed by multiple people. Overall, NeuroManager provides the infrastructure needed to improve workflow, manage multiple simultaneous simulations, and maintain provenance of the potentially large amounts of data produced during the course of a research project.

Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

Energy Technology Data Exchange (ETDEWEB)

Wang, Carolyn L., E-mail: wangcl@uw.edu [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Schopp, Jennifer G.; Kani, Kimia [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, 500 University Drive, Hershey, PA 17033 (United States); Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H. [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States)

2013-12-01

Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation.

Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

International Nuclear Information System (INIS)

Wang, Carolyn L.; Schopp, Jennifer G.; Kani, Kimia; Petscavage-Thomas, Jonelle M.; Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H.

2013-01-01

Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation

Computational Particle Dynamic Simulations on Multicore Processors (CPDMu) Final Report Phase I

Energy Technology Data Exchange (ETDEWEB)

Schmalz, Mark S

2011-07-24

Statement of Problem - Department of Energy has many legacy codes for simulation of computational particle dynamics and computational fluid dynamics applications that are designed to run on sequential processors and are not easily parallelized. Emerging high-performance computing architectures employ massively parallel multicore architectures (e.g., graphics processing units) to increase throughput. Parallelization of legacy simulation codes is a high priority, to achieve compatibility, efficiency, accuracy, and extensibility. General Statement of Solution - A legacy simulation application designed for implementation on mainly-sequential processors has been represented as a graph G. Mathematical transformations, applied to G, produce a graph representation {und G} for a high-performance architecture. Key computational and data movement kernels of the application were analyzed/optimized for parallel execution using the mapping G {yields} {und G}, which can be performed semi-automatically. This approach is widely applicable to many types of high-performance computing systems, such as graphics processing units or clusters comprised of nodes that contain one or more such units. Phase I Accomplishments - Phase I research decomposed/profiled computational particle dynamics simulation code for rocket fuel combustion into low and high computational cost regions (respectively, mainly sequential and mainly parallel kernels), with analysis of space and time complexity. Using the research team's expertise in algorithm-to-architecture mappings, the high-cost kernels were transformed, parallelized, and implemented on Nvidia Fermi GPUs. Measured speedups (GPU with respect to single-core CPU) were approximately 20-32X for realistic model parameters, without final optimization. Error analysis showed no loss of computational accuracy. Commercial Applications and Other Benefits - The proposed research will constitute a breakthrough in solution of problems related to efficient

The adaptation method in the Monte Carlo simulation for computed tomography

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyoung Gun; Yoon, Chang Yeon; Lee, Won Ho [Dept. of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); Cho, Seung Ryong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Sung Ho [Dept. of Neurosurgery, Ulsan University Hospital, Ulsan (Korea, Republic of)

2015-06-15

The patient dose incurred from diagnostic procedures during advanced radiotherapy has become an important issue. Many researchers in medical physics are using computational simulations to calculate complex parameters in experiments. However, extended computation times make it difficult for personal computers to run the conventional Monte Carlo method to simulate radiological images with high-flux photons such as images produced by computed tomography (CT). To minimize the computation time without degrading imaging quality, we applied a deterministic adaptation to the Monte Carlo calculation and verified its effectiveness by simulating CT image reconstruction for an image evaluation phantom (Catphan; Phantom Laboratory, New York NY, USA) and a human-like voxel phantom (KTMAN-2) (Los Alamos National Laboratory, Los Alamos, NM, USA). For the deterministic adaptation, the relationship between iteration numbers and the simulations was estimated and the option to simulate scattered radiation was evaluated. The processing times of simulations using the adaptive method were at least 500 times faster than those using a conventional statistical process. In addition, compared with the conventional statistical method, the adaptive method provided images that were more similar to the experimental images, which proved that the adaptive method was highly effective for a simulation that requires a large number of iterations-assuming no radiation scattering in the vicinity of detectors minimized artifacts in the reconstructed image.

Computational performance of a smoothed particle hydrodynamics simulation for shared-memory parallel computing

Science.gov (United States)

Nishiura, Daisuke; Furuichi, Mikito; Sakaguchi, Hide

2015-09-01

The computational performance of a smoothed particle hydrodynamics (SPH) simulation is investigated for three types of current shared-memory parallel computer devices: many integrated core (MIC) processors, graphics processing units (GPUs), and multi-core CPUs. We are especially interested in efficient shared-memory allocation methods for each chipset, because the efficient data access patterns differ between compute unified device architecture (CUDA) programming for GPUs and OpenMP programming for MIC processors and multi-core CPUs. We first introduce several parallel implementation techniques for the SPH code, and then examine these on our target computer architectures to determine the most effective algorithms for each processor unit. In addition, we evaluate the effective computing performance and power efficiency of the SPH simulation on each architecture, as these are critical metrics for overall performance in a multi-device environment. In our benchmark test, the GPU is found to produce the best arithmetic performance as a standalone device unit, and gives the most efficient power consumption. The multi-core CPU obtains the most effective computing performance. The computational speed of the MIC processor on Xeon Phi approached that of two Xeon CPUs. This indicates that using MICs is an attractive choice for existing SPH codes on multi-core CPUs parallelized by OpenMP, as it gains computational acceleration without the need for significant changes to the source code.

Using computer simulations to probe the structure and dynamics of biopolymers

International Nuclear Information System (INIS)

Levy, R.M.; Hirata, F.; Kim, K.; Zhang, P.

1987-01-01

The use of computer simulations to study internal motions and thermodynamic properties is receiving increased attention. One important use of the method is to provide a more fundamental understanding of the molecular information contained in various kinds of experiments on these complex systems. In the first part of this paper the authors review recent work in their laboratory concerned with the use of computer simulations for the interpretation of experimental probes of molecular structure and dynamics of proteins and nucleic acids. The interplay between computer simulations and three experimental techniques is emphasized: (1) nuclear magnetic resonance relaxation spectroscopy, (2) refinement of macro-molecular x-ray structures, and (3) vibrational spectroscopy. The treatment of solvent effects in biopolymer simulations is a difficult problem. It is not possible to study systematically the effect of solvent conditions, e.g. added salt concentration, on biopolymer properties by means of simulations alone. In the last part of the paper the authors review a more analytical approach they developed to study polyelectrolyte properties of solvated biopolymers. The results are compared with computer simulations

Digital control computer upgrade at the Cernavoda NPP simulator

International Nuclear Information System (INIS)

Ionescu, T.

2006-01-01

The Plant Process Computer equips some Nuclear Power Plants, like CANDU-600, with Centralized Control performed by an assembly of two computers known as Digital Control Computers (DCC) and working in parallel for safely driving of the plan at steady state and during normal maneuvers but also during abnormal transients when the plant is automatically steered to a safe state. The Centralized Control means both hardware and software with obligatory presence in the frame of the Full Scope Simulator and subject to changing its configuration with specific requirements during the plant and simulator life and covered by this subsection

Computer based training simulator for Hunterston Nuclear Power Station

International Nuclear Information System (INIS)

Bowden, R.S.M.; Hacking, D.

1978-01-01

For reasons which are stated, the Hunterston-B nuclear power station automatic control system includes a manual over-ride facility. It is therefore essential for the station engineers to be trained to recognise and control all feasible modes of plant and logic malfunction. A training simulator has been built which consists of a replica of the shutdown monitoring panel in the Central Control Room and is controlled by a mini-computer. This paper highlights the computer aspects of the simulator and relevant derived experience, under the following headings: engineering background; shutdown sequence equipment; simulator equipment; features; software; testing; maintenance. (U.K.)

Computer simulation games in population and education.

Science.gov (United States)

Moreland, R S

1988-01-01

Computer-based simulation games are effective training tools that have several advantages. They enable players to learn in a nonthreatening manner and develop strategies to achieve goals in a dynamic environment. They also provide visual feedback on the effects of players' decisions, encourage players to explore and experiment with options before making final decisions, and develop players' skills in analysis, decision making, and cooperation. 2 games have been developed by the Research Triangle Institute for public-sector planning agencies interested in or dealing with developing countries. The UN Population and Development Game teaches players about the interaction between population variables and the national economy and how population policies complement other national policies, such as education. The BRIDGES Education Planning Game focuses on the effects education has on national policies. In both games, the computer simulates the reactions of a fictional country's socioeconomic system to players' decisions. Players can change decisions after seeing their effects on a computer screen and thus can improve their performance in achieving goals.

Soft-error tolerance and energy consumption evaluation of embedded computer with magnetic random access memory in practical systems using computer simulations

Science.gov (United States)

Nebashi, Ryusuke; Sakimura, Noboru; Sugibayashi, Tadahiko

2017-08-01

We evaluated the soft-error tolerance and energy consumption of an embedded computer with magnetic random access memory (MRAM) using two computer simulators. One is a central processing unit (CPU) simulator of a typical embedded computer system. We simulated the radiation-induced single-event-upset (SEU) probability in a spin-transfer-torque MRAM cell and also the failure rate of a typical embedded computer due to its main memory SEU error. The other is a delay tolerant network (DTN) system simulator. It simulates the power dissipation of wireless sensor network nodes of the system using a revised CPU simulator and a network simulator. We demonstrated that the SEU effect on the embedded computer with 1 Gbit MRAM-based working memory is less than 1 failure in time (FIT). We also demonstrated that the energy consumption of the DTN sensor node with MRAM-based working memory can be reduced to 1/11. These results indicate that MRAM-based working memory enhances the disaster tolerance of embedded computers.

A note on simulated annealing to computer laboratory scheduling ...

African Journals Online (AJOL)

The concepts, principles and implementation of simulated Annealing as a modem heuristic technique is presented. Simulated Annealing algorithm is used in solving real life problem of Computer Laboratory scheduling in order to maximize the use of scarce and insufficient resources. KEY WORDS: Simulated Annealing ...

Time reversibility, computer simulation, algorithms, chaos

CERN Document Server

Hoover, William Graham

2012-01-01

A small army of physicists, chemists, mathematicians, and engineers has joined forces to attack a classic problem, the "reversibility paradox", with modern tools. This book describes their work from the perspective of computer simulation, emphasizing the author's approach to the problem of understanding the compatibility, and even inevitability, of the irreversible second law of thermodynamics with an underlying time-reversible mechanics. Computer simulation has made it possible to probe reversibility from a variety of directions and "chaos theory" or "nonlinear dynamics" has supplied a useful vocabulary and a set of concepts, which allow a fuller explanation of irreversibility than that available to Boltzmann or to Green, Kubo and Onsager. Clear illustration of concepts is emphasized throughout, and reinforced with a glossary of technical terms from the specialized fields which have been combined here to focus on a common theme. The book begins with a discussion, contrasting the idealized reversibility of ba...

Simulation of Robot Kinematics Using Interactive Computer Graphics.

Science.gov (United States)

Leu, M. C.; Mahajan, R.

1984-01-01

Development of a robot simulation program based on geometric transformation softwares available in most computer graphics systems and program features are described. The program can be extended to simulate robots coordinating with external devices (such as tools, fixtures, conveyors) using geometric transformations to describe the…

Computer simulations of long-time tails: what's new?

NARCIS (Netherlands)

Hoef, van der M.A.; Frenkel, D.

1995-01-01

Twenty five years ago Alder and Wainwright discovered, by simulation, the 'long-time tails' in the velocity autocorrelation function of a single particle in fluid [1]. Since then, few qualitatively new results on long-time tails have been obtained by computer simulations. However, within the

Faster quantum chemistry simulation on fault-tolerant quantum computers

International Nuclear Information System (INIS)

Cody Jones, N; McMahon, Peter L; Yamamoto, Yoshihisa; Whitfield, James D; Yung, Man-Hong; Aspuru-Guzik, Alán; Van Meter, Rodney

2012-01-01

Quantum computers can in principle simulate quantum physics exponentially faster than their classical counterparts, but some technical hurdles remain. We propose methods which substantially improve the performance of a particular form of simulation, ab initio quantum chemistry, on fault-tolerant quantum computers; these methods generalize readily to other quantum simulation problems. Quantum teleportation plays a key role in these improvements and is used extensively as a computing resource. To improve execution time, we examine techniques for constructing arbitrary gates which perform substantially faster than circuits based on the conventional Solovay–Kitaev algorithm (Dawson and Nielsen 2006 Quantum Inform. Comput. 6 81). For a given approximation error ϵ, arbitrary single-qubit gates can be produced fault-tolerantly and using a restricted set of gates in time which is O(log ϵ) or O(log log ϵ); with sufficient parallel preparation of ancillas, constant average depth is possible using a method we call programmable ancilla rotations. Moreover, we construct and analyze efficient implementations of first- and second-quantized simulation algorithms using the fault-tolerant arbitrary gates and other techniques, such as implementing various subroutines in constant time. A specific example we analyze is the ground-state energy calculation for lithium hydride. (paper)

Performance Analysis of Cloud Computing Architectures Using Discrete Event Simulation

Science.gov (United States)

Stocker, John C.; Golomb, Andrew M.

2011-01-01

Cloud computing offers the economic benefit of on-demand resource allocation to meet changing enterprise computing needs. However, the flexibility of cloud computing is disadvantaged when compared to traditional hosting in providing predictable application and service performance. Cloud computing relies on resource scheduling in a virtualized network-centric server environment, which makes static performance analysis infeasible. We developed a discrete event simulation model to evaluate the overall effectiveness of organizations in executing their workflow in traditional and cloud computing architectures. The two part model framework characterizes both the demand using a probability distribution for each type of service request as well as enterprise computing resource constraints. Our simulations provide quantitative analysis to design and provision computing architectures that maximize overall mission effectiveness. We share our analysis of key resource constraints in cloud computing architectures and findings on the appropriateness of cloud computing in various applications.

Toward real-time Monte Carlo simulation using a commercial cloud computing infrastructure.

Science.gov (United States)

Wang, Henry; Ma, Yunzhi; Pratx, Guillem; Xing, Lei

2011-09-07

Monte Carlo (MC) methods are the gold standard for modeling photon and electron transport in a heterogeneous medium; however, their computational cost prohibits their routine use in the clinic. Cloud computing, wherein computing resources are allocated on-demand from a third party, is a new approach for high performance computing and is implemented to perform ultra-fast MC calculation in radiation therapy. We deployed the EGS5 MC package in a commercial cloud environment. Launched from a single local computer with Internet access, a Python script allocates a remote virtual cluster. A handshaking protocol designates master and worker nodes. The EGS5 binaries and the simulation data are initially loaded onto the master node. The simulation is then distributed among independent worker nodes via the message passing interface, and the results aggregated on the local computer for display and data analysis. The described approach is evaluated for pencil beams and broad beams of high-energy electrons and photons. The output of cloud-based MC simulation is identical to that produced by single-threaded implementation. For 1 million electrons, a simulation that takes 2.58 h on a local computer can be executed in 3.3 min on the cloud with 100 nodes, a 47× speed-up. Simulation time scales inversely with the number of parallel nodes. The parallelization overhead is also negligible for large simulations. Cloud computing represents one of the most important recent advances in supercomputing technology and provides a promising platform for substantially improved MC simulation. In addition to the significant speed up, cloud computing builds a layer of abstraction for high performance parallel computing, which may change the way dose calculations are performed and radiation treatment plans are completed.

Toward real-time Monte Carlo simulation using a commercial cloud computing infrastructure

International Nuclear Information System (INIS)

Wang, Henry; Ma Yunzhi; Pratx, Guillem; Xing Lei

2011-01-01

Monte Carlo (MC) methods are the gold standard for modeling photon and electron transport in a heterogeneous medium; however, their computational cost prohibits their routine use in the clinic. Cloud computing, wherein computing resources are allocated on-demand from a third party, is a new approach for high performance computing and is implemented to perform ultra-fast MC calculation in radiation therapy. We deployed the EGS5 MC package in a commercial cloud environment. Launched from a single local computer with Internet access, a Python script allocates a remote virtual cluster. A handshaking protocol designates master and worker nodes. The EGS5 binaries and the simulation data are initially loaded onto the master node. The simulation is then distributed among independent worker nodes via the message passing interface, and the results aggregated on the local computer for display and data analysis. The described approach is evaluated for pencil beams and broad beams of high-energy electrons and photons. The output of cloud-based MC simulation is identical to that produced by single-threaded implementation. For 1 million electrons, a simulation that takes 2.58 h on a local computer can be executed in 3.3 min on the cloud with 100 nodes, a 47x speed-up. Simulation time scales inversely with the number of parallel nodes. The parallelization overhead is also negligible for large simulations. Cloud computing represents one of the most important recent advances in supercomputing technology and provides a promising platform for substantially improved MC simulation. In addition to the significant speed up, cloud computing builds a layer of abstraction for high performance parallel computing, which may change the way dose calculations are performed and radiation treatment plans are completed. (note)

Toward real-time Monte Carlo simulation using a commercial cloud computing infrastructure

Energy Technology Data Exchange (ETDEWEB)

Wang, Henry [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Ma Yunzhi; Pratx, Guillem; Xing Lei, E-mail: hwang41@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305-5847 (United States)

2011-09-07

Monte Carlo (MC) methods are the gold standard for modeling photon and electron transport in a heterogeneous medium; however, their computational cost prohibits their routine use in the clinic. Cloud computing, wherein computing resources are allocated on-demand from a third party, is a new approach for high performance computing and is implemented to perform ultra-fast MC calculation in radiation therapy. We deployed the EGS5 MC package in a commercial cloud environment. Launched from a single local computer with Internet access, a Python script allocates a remote virtual cluster. A handshaking protocol designates master and worker nodes. The EGS5 binaries and the simulation data are initially loaded onto the master node. The simulation is then distributed among independent worker nodes via the message passing interface, and the results aggregated on the local computer for display and data analysis. The described approach is evaluated for pencil beams and broad beams of high-energy electrons and photons. The output of cloud-based MC simulation is identical to that produced by single-threaded implementation. For 1 million electrons, a simulation that takes 2.58 h on a local computer can be executed in 3.3 min on the cloud with 100 nodes, a 47x speed-up. Simulation time scales inversely with the number of parallel nodes. The parallelization overhead is also negligible for large simulations. Cloud computing represents one of the most important recent advances in supercomputing technology and provides a promising platform for substantially improved MC simulation. In addition to the significant speed up, cloud computing builds a layer of abstraction for high performance parallel computing, which may change the way dose calculations are performed and radiation treatment plans are completed. (note)

Using Palm Technology in Participatory Simulations of Complex Systems: A New Take on Ubiquitous and Accessible Mobile Computing

Science.gov (United States)

Klopfer, Eric; Yoon, Susan; Perry, Judy

2005-09-01

This paper reports on teachers' perceptions of the educational affordances of a handheld application called Participatory Simulations. It presents evidence from five cases representing each of the populations who work with these computational tools. Evidence across multiple data sources yield similar results to previous research evaluations of handheld activities with respect to enhancing motivation, engagement and self-directed learning. Three additional themes are discussed that provide insight into understanding curricular applicability of Participatory Simulations that suggest a new take on ubiquitous and accessible mobile computing. These themes generally point to the multiple layers of social and cognitive flexibility intrinsic to their design: ease of adaptation to subject-matter content knowledge and curricular integration; facility in attending to teacher-individualized goals; and encouraging the adoption of learner-centered strategies.

Computer simulation of high energy displacement cascades

International Nuclear Information System (INIS)

Heinisch, H.L.

1990-01-01

A methodology developed for modeling many aspects of high energy displacement cascades with molecular level computer simulations is reviewed. The initial damage state is modeled in the binary collision approximation (using the MARLOWE computer code), and the subsequent disposition of the defects within a cascade is modeled with a Monte Carlo annealing simulation (the ALSOME code). There are few adjustable parameters, and none are set to physically unreasonable values. The basic configurations of the simulated high energy cascades in copper, i.e., the number, size and shape of damage regions, compare well with observations, as do the measured numbers of residual defects and the fractions of freely migrating defects. The success of these simulations is somewhat remarkable, given the relatively simple models of defects and their interactions that are employed. The reason for this success is that the behavior of the defects is very strongly influenced by their initial spatial distributions, which the binary collision approximation adequately models. The MARLOWE/ALSOME system, with input from molecular dynamics and experiments, provides a framework for investigating the influence of high energy cascades on microstructure evolution. (author)

The advanced computational testing and simulation toolkit (ACTS)

International Nuclear Information System (INIS)

Drummond, L.A.; Marques, O.

2002-01-01

During the past decades there has been a continuous growth in the number of physical and societal problems that have been successfully studied and solved by means of computational modeling and simulation. Distinctively, a number of these are important scientific problems ranging in scale from the atomic to the cosmic. For example, ionization is a phenomenon as ubiquitous in modern society as the glow of fluorescent lights and the etching on silicon computer chips; but it was not until 1999 that researchers finally achieved a complete numerical solution to the simplest example of ionization, the collision of a hydrogen atom with an electron. On the opposite scale, cosmologists have long wondered whether the expansion of the Universe, which began with the Big Bang, would ever reverse itself, ending the Universe in a Big Crunch. In 2000, analysis of new measurements of the cosmic microwave background radiation showed that the geometry of the Universe is flat, and thus the Universe will continue expanding forever. Both of these discoveries depended on high performance computer simulations that utilized computational tools included in the Advanced Computational Testing and Simulation (ACTS) Toolkit. The ACTS Toolkit is an umbrella project that brought together a number of general purpose computational tool development projects funded and supported by the U.S. Department of Energy (DOE). These tools, which have been developed independently, mainly at DOE laboratories, make it easier for scientific code developers to write high performance applications for parallel computers. They tackle a number of computational issues that are common to a large number of scientific applications, mainly implementation of numerical algorithms, and support for code development, execution and optimization. The ACTS Toolkit Project enables the use of these tools by a much wider community of computational scientists, and promotes code portability, reusability, reduction of duplicate efforts

The advanced computational testing and simulation toolkit (ACTS)

Energy Technology Data Exchange (ETDEWEB)

Drummond, L.A.; Marques, O.

2002-05-21

During the past decades there has been a continuous growth in the number of physical and societal problems that have been successfully studied and solved by means of computational modeling and simulation. Distinctively, a number of these are important scientific problems ranging in scale from the atomic to the cosmic. For example, ionization is a phenomenon as ubiquitous in modern society as the glow of fluorescent lights and the etching on silicon computer chips; but it was not until 1999 that researchers finally achieved a complete numerical solution to the simplest example of ionization, the collision of a hydrogen atom with an electron. On the opposite scale, cosmologists have long wondered whether the expansion of the Universe, which began with the Big Bang, would ever reverse itself, ending the Universe in a Big Crunch. In 2000, analysis of new measurements of the cosmic microwave background radiation showed that the geometry of the Universe is flat, and thus the Universe will continue expanding forever. Both of these discoveries depended on high performance computer simulations that utilized computational tools included in the Advanced Computational Testing and Simulation (ACTS) Toolkit. The ACTS Toolkit is an umbrella project that brought together a number of general purpose computational tool development projects funded and supported by the U.S. Department of Energy (DOE). These tools, which have been developed independently, mainly at DOE laboratories, make it easier for scientific code developers to write high performance applications for parallel computers. They tackle a number of computational issues that are common to a large number of scientific applications, mainly implementation of numerical algorithms, and support for code development, execution and optimization. The ACTS Toolkit Project enables the use of these tools by a much wider community of computational scientists, and promotes code portability, reusability, reduction of duplicate efforts

The Use of Computer Simulation Gaming in Teaching Broadcast Economics.

Science.gov (United States)

Mancuso, Louis C.

The purpose of this study was to develop a broadcast economic computer simulation and to ascertain how a lecture-computer simulation game compared as a teaching method with a more traditional lecture and case study instructional methods. In each of three sections of a broadcast economics course, a different teaching methodology was employed: (1)…

SPINET: A Parallel Computing Approach to Spine Simulations

Directory of Open Access Journals (Sweden)

Peter G. Kropf

1996-01-01

Full Text Available Research in scientitic programming enables us to realize more and more complex applications, and on the other hand, application-driven demands on computing methods and power are continuously growing. Therefore, interdisciplinary approaches become more widely used. The interdisciplinary SPINET project presented in this article applies modern scientific computing tools to biomechanical simulations: parallel computing and symbolic and modern functional programming. The target application is the human spine. Simulations of the spine help us to investigate and better understand the mechanisms of back pain and spinal injury. Two approaches have been used: the first uses the finite element method for high-performance simulations of static biomechanical models, and the second generates a simulation developmenttool for experimenting with different dynamic models. A finite element program for static analysis has been parallelized for the MUSIC machine. To solve the sparse system of linear equations, a conjugate gradient solver (iterative method and a frontal solver (direct method have been implemented. The preprocessor required for the frontal solver is written in the modern functional programming language SML, the solver itself in C, thus exploiting the characteristic advantages of both functional and imperative programming. The speedup analysis of both solvers show very satisfactory results for this irregular problem. A mixed symbolic-numeric environment for rigid body system simulations is presented. It automatically generates C code from a problem specification expressed by the Lagrange formalism using Maple.

Computer simulation of two-phase flow in nuclear reactors

International Nuclear Information System (INIS)

Wulff, W.

1993-01-01

Two-phase flow models dominate the requirements of economic resources for the development and use of computer codes which serve to analyze thermohydraulic transients in nuclear power plants. An attempt is made to reduce the effort of analyzing reactor transients by combining purpose-oriented modelling with advanced computing techniques. Six principles are presented on mathematical modeling and the selection of numerical methods, along with suggestions on programming and machine selection, all aimed at reducing the cost of analysis. Computer simulation is contrasted with traditional computer calculation. The advantages of run-time interactive access operation in a simulation environment are demonstrated. It is explained that the drift-flux model is better suited than the two-fluid model for the analysis of two-phase flow in nuclear reactors, because of the latter's closure problems. The advantage of analytical over numerical integration is demonstrated. Modeling and programming techniques are presented which minimize the number of needed arithmetical and logical operations and thereby increase the simulation speed, while decreasing the cost. (orig.)

Computer simulation of molecular sorption in zeolites

International Nuclear Information System (INIS)

Calmiano, Mark Daniel

2001-01-01

The work presented in this thesis encompasses the computer simulation of molecular sorption. In Chapter 1 we outline the aims and objectives of this work. Chapter 2 follows in which an introduction to sorption in zeolites is presented, with discussion of structure and properties of the main zeolites studied. Chapter 2 concludes with a description of the principles and theories of adsorption. In Chapter 3 we describe the methodology behind the work carried out in this thesis. In Chapter 4 we present our first computational study, that of the sorption of krypton in silicalite. We describe work carried out to investigate low energy sorption sites of krypton in silicalite where we observe krypton to preferentially sorb into straight and sinusoidal channels over channel intersections. We simulate single step type I adsorption isotherms and use molecular dynamics to study the diffusion of krypton and obtain division coefficients and the activation energy. We compare our results to previous experimental and computational studies where we show our work to be in good agreement. In Chapter 5 we present a systematic study of the sorption of oxygen and nitrogen in five lithium substituted zeolites using a transferable interatomic potential that we have developed from ab initio calculations. We show increased loading of nitrogen compared to oxygen in all five zeolites studied as expected and simulate adsorption isotherms, which we compare to experimental and simulated data in the literature. In Chapter 6 we present work on the sorption of ferrocene in the zeolite NaY. We show that a simulated, low energy sorption site for ferrocene is correctly located by comparing to X-ray powder diffraction results for this same system. The thesis concludes with some overall conclusions and discussion of opportunities for future work. (author)

Factors cost effectively improved using computer simulations of ...

African Journals Online (AJOL)

LPhidza

effectively managed using computer simulations in semi-arid conditions pertinent to much of sub-Saharan Africa. ... small scale farmers to obtain optimal crop yields thus ensuring their food security and livelihood is ... those that simultaneously incorporate and simulate processes involved throughout the course of crop ...

CloudMC: a cloud computing application for Monte Carlo simulation

International Nuclear Information System (INIS)

Miras, H; Jiménez, R; Miras, C; Gomà, C

2013-01-01

This work presents CloudMC, a cloud computing application—developed in Windows Azure®, the platform of the Microsoft® cloud—for the parallelization of Monte Carlo simulations in a dynamic virtual cluster. CloudMC is a web application designed to be independent of the Monte Carlo code in which the simulations are based—the simulations just need to be of the form: input files → executable → output files. To study the performance of CloudMC in Windows Azure®, Monte Carlo simulations with penelope were performed on different instance (virtual machine) sizes, and for different number of instances. The instance size was found to have no effect on the simulation runtime. It was also found that the decrease in time with the number of instances followed Amdahl's law, with a slight deviation due to the increase in the fraction of non-parallelizable time with increasing number of instances. A simulation that would have required 30 h of CPU on a single instance was completed in 48.6 min when executed on 64 instances in parallel (speedup of 37 ×). Furthermore, the use of cloud computing for parallel computing offers some advantages over conventional clusters: high accessibility, scalability and pay per usage. Therefore, it is strongly believed that cloud computing will play an important role in making Monte Carlo dose calculation a reality in future clinical practice. (note)

CloudMC: a cloud computing application for Monte Carlo simulation.

Science.gov (United States)

Miras, H; Jiménez, R; Miras, C; Gomà, C

2013-04-21

This work presents CloudMC, a cloud computing application-developed in Windows Azure®, the platform of the Microsoft® cloud-for the parallelization of Monte Carlo simulations in a dynamic virtual cluster. CloudMC is a web application designed to be independent of the Monte Carlo code in which the simulations are based-the simulations just need to be of the form: input files → executable → output files. To study the performance of CloudMC in Windows Azure®, Monte Carlo simulations with penelope were performed on different instance (virtual machine) sizes, and for different number of instances. The instance size was found to have no effect on the simulation runtime. It was also found that the decrease in time with the number of instances followed Amdahl's law, with a slight deviation due to the increase in the fraction of non-parallelizable time with increasing number of instances. A simulation that would have required 30 h of CPU on a single instance was completed in 48.6 min when executed on 64 instances in parallel (speedup of 37 ×). Furthermore, the use of cloud computing for parallel computing offers some advantages over conventional clusters: high accessibility, scalability and pay per usage. Therefore, it is strongly believed that cloud computing will play an important role in making Monte Carlo dose calculation a reality in future clinical practice.

New Frontiers in Analyzing Dynamic Group Interactions: Bridging Social and Computer Science.

Science.gov (United States)

Lehmann-Willenbrock, Nale; Hung, Hayley; Keyton, Joann

2017-10-01

This special issue on advancing interdisciplinary collaboration between computer scientists and social scientists documents the joint results of the international Lorentz workshop, "Interdisciplinary Insights into Group and Team Dynamics," which took place in Leiden, The Netherlands, July 2016. An equal number of scholars from social and computer science participated in the workshop and contributed to the papers included in this special issue. In this introduction, we first identify interaction dynamics as the core of group and team models and review how scholars in social and computer science have typically approached behavioral interactions in groups and teams. Next, we identify key challenges for interdisciplinary collaboration between social and computer scientists, and we provide an overview of the different articles in this special issue aimed at addressing these challenges.

A real-time computer simulation of nuclear simulator software using standard PC hardware and linux environments

International Nuclear Information System (INIS)

Cha, K. H.; Kweon, K. C.

2001-01-01

A feasibility study, which standard PC hardware and Real-Time Linux are applied to real-time computer simulation of software for a nuclear simulator, is presented in this paper. The feasibility prototype was established with the existing software in the Compact Nuclear Simulator (CNS). Throughout the real-time implementation in the feasibility prototype, we has identified that the approach can enable the computer-based predictive simulation to be approached, due to both the remarkable improvement in real-time performance and the less efforts for real-time implementation under standard PC hardware and Real-Time Linux envrionments

Social Structure Simulation and Inference Using Artificial Intelligence Techniques

National Research Council Canada - National Science Library

Tsvetovat, Maksim

2005-01-01

.... As available computing power grew, social network-based models have become not only an analysis tool, but also a methodology for building new theories of social behaviour and organizational evolution...

Public Services 2.0: The Impact of Social Computing on Public Services

OpenAIRE

Punie, Y.; Misuraca, G.; Osimo, D.; Huijboom, N.; Broek, T.A. van den; Frissen, V.; Kool, L.

2010-01-01

Since 2003, the Internet has seen impressive growth in user-driven applications such as blogs, podcasts, wikis and social networking sites. This trend is referred to here as ‘social computing’ as online applications increasingly support the creation of value by social networks of people. The social computing trend has been recognised and monitored by the Institute for Prospective and Technological Studies (IPTS) over the past few years. IPTS observed a viral take up of social computing applic...

Formal Analysis of Dynamics Within Philosophy of Mind by Computer Simulation

NARCIS (Netherlands)

Bosse, T.; Schut, M.C.; Treur, J.

2009-01-01

Computer simulations can be useful tools to support philosophers in validating their theories, especially when these theories concern phenomena showing nontrivial dynamics. Such theories are usually informal, whilst for computer simulation a formally described model is needed. In this paper, a

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

OpenAIRE

Qiang Liu; Yi Qin; Guodong Li

2018-01-01

Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal...

Computer simulation studies in condensed-matter physics 5. Proceedings

International Nuclear Information System (INIS)

Landau, D.P.; Mon, K.K.; Schuettler, H.B.

1993-01-01

As the role of computer simulations began to increase in importance, we sensed a need for a ''meeting place'' for both experienced simulators and neophytes to discuss new techniques and results in an environment which promotes extended discussion. As a consequence of these concerns, The Center for Simulational Physics established an annual workshop on Recent Developments in Computer Simulation Studies in Condensed-Matter Physics. This year's workshop was the fifth in this series and the interest which the scientific community has shown demonstrates quite clearly the useful purpose which the series has served. The workshop was held at the University of Georgia, February 17-21, 1992, and these proceedings from a record of the workshop which is published with the goal of timely dissemination of the papers to a wider audience. The proceedings are divided into four parts. The first part contains invited papers which deal with simulational studies of classical systems and includes an introduction to some new simulation techniques and special purpose computers as well. A separate section of the proceedings is devoted to invited papers on quantum systems including new results for strongly correlated electron and quantum spin models. The third section is comprised of a single, invited description of a newly developed software shell designed for running parallel programs. The contributed presentations comprise the final chapter. (orig.). 79 figs

A compositional reservoir simulator on distributed memory parallel computers

International Nuclear Information System (INIS)

Rame, M.; Delshad, M.

1995-01-01

This paper presents the application of distributed memory parallel computes to field scale reservoir simulations using a parallel version of UTCHEM, The University of Texas Chemical Flooding Simulator. The model is a general purpose highly vectorized chemical compositional simulator that can simulate a wide range of displacement processes at both field and laboratory scales. The original simulator was modified to run on both distributed memory parallel machines (Intel iPSC/960 and Delta, Connection Machine 5, Kendall Square 1 and 2, and CRAY T3D) and a cluster of workstations. A domain decomposition approach has been taken towards parallelization of the code. A portion of the discrete reservoir model is assigned to each processor by a set-up routine that attempts a data layout as even as possible from the load-balance standpoint. Each of these subdomains is extended so that data can be shared between adjacent processors for stencil computation. The added routines that make parallel execution possible are written in a modular fashion that makes the porting to new parallel platforms straight forward. Results of the distributed memory computing performance of Parallel simulator are presented for field scale applications such as tracer flood and polymer flood. A comparison of the wall-clock times for same problems on a vector supercomputer is also presented

Computer simulation of ultrasonic waves in solids

International Nuclear Information System (INIS)

Thibault, G.A.; Chaplin, K.

1992-01-01

A computer model that simulates the propagation of ultrasonic waves has been developed at AECL Research, Chalk River Laboratories. This program is called EWE, short for Elastic Wave Equations, the mathematics governing the propagation of ultrasonic waves. This report contains a brief summary of the use of ultrasonic waves in non-destructive testing techniques, a discussion of the EWE simulation code explaining the implementation of the equations and the types of output received from the model, and an example simulation showing the abilities of the model. (author). 2 refs., 2 figs

COMPUTER MODEL AND SIMULATION OF A GLOVE BOX PROCESS

International Nuclear Information System (INIS)

Foster, C.

2001-01-01

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

Thermodynamic and transport properties of nitrogen fluid: Molecular theory and computer simulations

Science.gov (United States)

Eskandari Nasrabad, A.; Laghaei, R.

2018-04-01

Computer simulations and various theories are applied to compute the thermodynamic and transport properties of nitrogen fluid. To model the nitrogen interaction, an existing potential in the literature is modified to obtain a close agreement between the simulation results and experimental data for the orthobaric densities. We use the Generic van der Waals theory to calculate the mean free volume and apply the results within the modified Cohen-Turnbull relation to obtain the self-diffusion coefficient. Compared to experimental data, excellent results are obtained via computer simulations for the orthobaric densities, the vapor pressure, the equation of state, and the shear viscosity. We analyze the results of the theory and computer simulations for the various thermophysical properties.

Computer simulation for sodium-concrete reactions

International Nuclear Information System (INIS)

Zhang Bin; Zhu Jizhou

2006-01-01

In the liquid metal cooled fast breeder reactors (LMFBRs), direct contacts between sodium and concrete is unavoidable. Due to sodium's high chemical reactivity, sodium would react with concrete violently. Lots of hydrogen gas and heat would be released then. This would harm the ignorantly of the containment. This paper developed a program to simualte sodium-conrete reactions across-the-board. It could give the reaction zone temperature, pool temperature, penetration depth, penetration rate, hydrogen flux and reaction heat and so on. Concrete was considered to be composed of silica and water only in this paper. The variable, the quitient of sodium hydroxide, was introduced in the continuity equation to simulate the chemical reactions more realistically. The product of the net gas flux and boundary depth was ably transformed to that of penetration rate and boundary depth. The complex chemical kinetics equations was simplified under some hypothesises. All the technique applied above simplified the computer simulation consumedly. In other words, they made the computer simulation feasible. Theoretics models that applied in the program and the calculation procedure were expatiated in detail. Good agreements of an overall transient behavior were obtained in the series of sodium-concrete reaction experiment analysis. The comparison between the analytical and experimental results showed the program presented in this paper was creditable and reasonable for simulating the sodium-concrete reactions. This program could be used for nuclear safety judgement. (authors)

How Crime Spreads Through Imitation in Social Networks: A Simulation Model

Science.gov (United States)

Punzo, Valentina

In this chapter an agent-based model for investigating how crime spreads through social networks is presented. Some theoretical issues related to the sociological explanation of crime are tested through simulation. The agent-based simulation allows us to investigate the relative impact of some mechanisms of social influence on crime, within a set of controlled simulated experiments.

A review of computer-based simulators for ultrasound training.

Science.gov (United States)

Blum, Tobias; Rieger, Andreas; Navab, Nassir; Friess, Helmut; Martignoni, Marc

2013-04-01

Computer-based simulators for ultrasound training are a topic of recent interest. During the last 15 years, many different systems and methods have been proposed. This article provides an overview and classification of systems in this domain and a discussion of their advantages. Systems are classified and discussed according to the image simulation method, user interactions and medical applications. Computer simulation of ultrasound has one key advantage over traditional training. It enables novel training concepts, for example, through advanced visualization, case databases, and automatically generated feedback. Qualitative evaluations have mainly shown positive learning effects. However, few quantitative evaluations have been performed and long-term effects have to be examined.

Computer Graphics Simulations of Sampling Distributions.

Science.gov (United States)

Gordon, Florence S.; Gordon, Sheldon P.

1989-01-01

Describes the use of computer graphics simulations to enhance student understanding of sampling distributions that arise in introductory statistics. Highlights include the distribution of sample proportions, the distribution of the difference of sample means, the distribution of the difference of sample proportions, and the distribution of sample…

Computer simulation of nonequilibrium processes

International Nuclear Information System (INIS)

Wallace, D.C.

1985-07-01

The underlying concepts of nonequilibrium statistical mechanics, and of irreversible thermodynamics, will be described. The question at hand is then, how are these concepts to be realize in computer simulations of many-particle systems. The answer will be given for dissipative deformation processes in solids, on three hierarchical levels: heterogeneous plastic flow, dislocation dynamics, an molecular dynamics. Aplication to the shock process will be discussed

Building an adiabatic quantum computer simulation in the classroom

Science.gov (United States)

Rodríguez-Laguna, Javier; Santalla, Silvia N.

2018-05-01

We present a didactic introduction to adiabatic quantum computation (AQC) via the explicit construction of a classical simulator of quantum computers. This constitutes a suitable route to introduce several important concepts for advanced undergraduates in physics: quantum many-body systems, quantum phase transitions, disordered systems, spin-glasses, and computational complexity theory.

Agent Based Modelling for Social Simulation

OpenAIRE

Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

2013-01-01

This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course of this project two workshops were organized. At these workshops, a wide range of experts, both ABM experts and domain experts, worked on several potential applications of ABM. The results and ins...

Entertainment computing, social transformation and the quantum field

OpenAIRE

Rauterberg, G.W.M.; Nijholt, A.; Reidsma, D.; Hondorp, H.

2009-01-01

Entertainment computing is on its way getting an established academic discipline. The scope of entertainment computing is quite broad (see the scope of the international journal Entertainment Computing). One unifying idea in this diverse community of entertainment researchers and developers might be a normative position to enhance human living through social transformation. One possible option in this direction is a shared `conscious' field. Several ideas about a new kind of field based on qu...

Quantum computer gate simulations | Dada | Journal of the Nigerian ...

African Journals Online (AJOL)

A new interactive simulator for Quantum Computation has been developed for simulation of the universal set of quantum gates and for construction of new gates of up to 3 qubits. The simulator also automatically generates an equivalent quantum circuit for any arbitrary unitary transformation on a qubit. Available quantum ...

Computer-Assisted Instruction in Social Work.

Science.gov (United States)

Ehlers, Walter H.

After a discussion of the need for analyzing knowledge bases in the areas of psychology, Freudian concepts, child development, and the sociology of students entering a master's program in social work, this report examines concepts of simulation, straight line, and branching in computerized teaching, the diagnostic evaluation possibilities of…

AN EVALUATION AND IMPLEMENTATION OF COLLABORATIVE AND SOCIAL NETWORKING TECHNOLOGIES FOR COMPUTER EDUCATION

Directory of Open Access Journals (Sweden)

Ronnie Cheung

2011-06-01

Full Text Available We have developed a collaborative and social networking environment that integrates the knowledge and skills in communication and computing studies with a multimedia development project. The outcomes of the students’ projects show that computer literacy can be enhanced through a cluster of communication, social, and digital skills. Experience in implementing a web-based social networking environment shows that the new media is an effective means of enriching knowledge by sharing in computer literacy projects. The completed assignments, projects, and self-reflection reports demonstrate that the students were able to achieve the learning outcomes of a computer literacy course in multimedia development. The students were able to assess the effectiveness of a variety of media through the development of media presentations in a web-based, social-networking environment. In the collaborative and social-networking environment, students were able to collaborate and communicate with their team members to solve problems, resolve conflicts, make decisions, and work as a team to complete tasks. Our experience has shown that social networking environments are effective for computer literacy education, and the development of the new media is emerging as the core knowledge for computer literacy education.

Application of parallel computing techniques to a large-scale reservoir simulation

International Nuclear Information System (INIS)

Zhang, Keni; Wu, Yu-Shu; Ding, Chris; Pruess, Karsten

2001-01-01

Even with the continual advances made in both computational algorithms and computer hardware used in reservoir modeling studies, large-scale simulation of fluid and heat flow in heterogeneous reservoirs remains a challenge. The problem commonly arises from intensive computational requirement for detailed modeling investigations of real-world reservoirs. This paper presents the application of a massive parallel-computing version of the TOUGH2 code developed for performing large-scale field simulations. As an application example, the parallelized TOUGH2 code is applied to develop a three-dimensional unsaturated-zone numerical model simulating flow of moisture, gas, and heat in the unsaturated zone of Yucca Mountain, Nevada, a potential repository for high-level radioactive waste. The modeling approach employs refined spatial discretization to represent the heterogeneous fractured tuffs of the system, using more than a million 3-D gridblocks. The problem of two-phase flow and heat transfer within the model domain leads to a total of 3,226,566 linear equations to be solved per Newton iteration. The simulation is conducted on a Cray T3E-900, a distributed-memory massively parallel computer. Simulation results indicate that the parallel computing technique, as implemented in the TOUGH2 code, is very efficient. The reliability and accuracy of the model results have been demonstrated by comparing them to those of small-scale (coarse-grid) models. These comparisons show that simulation results obtained with the refined grid provide more detailed predictions of the future flow conditions at the site, aiding in the assessment of proposed repository performance

Advanced computational simulations of water waves interacting with wave energy converters

Science.gov (United States)

Pathak, Ashish; Freniere, Cole; Raessi, Mehdi

2017-03-01

Wave energy converter (WEC) devices harness the renewable ocean wave energy and convert it into useful forms of energy, e.g. mechanical or electrical. This paper presents an advanced 3D computational framework to study the interaction between water waves and WEC devices. The computational tool solves the full Navier-Stokes equations and considers all important effects impacting the device performance. To enable large-scale simulations in fast turnaround times, the computational solver was developed in an MPI parallel framework. A fast multigrid preconditioned solver is introduced to solve the computationally expensive pressure Poisson equation. The computational solver was applied to two surface-piercing WEC geometries: bottom-hinged cylinder and flap. Their numerically simulated response was validated against experimental data. Additional simulations were conducted to investigate the applicability of Froude scaling in predicting full-scale WEC response from the model experiments.

Cluster computing for lattice QCD simulations

International Nuclear Information System (INIS)

Coddington, P.D.; Williams, A.G.

2000-01-01

Full text: Simulations of lattice quantum chromodynamics (QCD) require enormous amounts of compute power. In the past, this has usually involved sharing time on large, expensive machines at supercomputing centres. Over the past few years, clusters of networked computers have become very popular as a low-cost alternative to traditional supercomputers. The dramatic improvements in performance (and more importantly, the ratio of price/performance) of commodity PCs, workstations, and networks have made clusters of off-the-shelf computers an attractive option for low-cost, high-performance computing. A major advantage of clusters is that since they can have any number of processors, they can be purchased using any sized budget, allowing research groups to install a cluster for their own dedicated use, and to scale up to more processors if additional funds become available. Clusters are now being built for high-energy physics simulations. Wuppertal has recently installed ALiCE, a cluster of 128 Alpha workstations running Linux, with a peak performance of 158 G flops. The Jefferson Laboratory in the US has a 16 node Alpha cluster and plans to upgrade to a 256 processor machine. In Australia, several large clusters have recently been installed. Swinburne University of Technology has a cluster of 64 Compaq Alpha workstations used for astrophysics simulations. Early this year our DHPC group constructed a cluster of 116 dual Pentium PCs (i.e. 232 processors) connected by a Fast Ethernet network, which is used by chemists at Adelaide University and Flinders University to run computational chemistry codes. The Australian National University has recently installed a similar PC cluster with 192 processors. The Centre for the Subatomic Structure of Matter (CSSM) undertakes large-scale high-energy physics calculations, mainly lattice QCD simulations. The choice of the computer and network hardware for a cluster depends on the particular applications to be run on the machine. Our

Computer Networks E-learning Based on Interactive Simulations and SCORM

Directory of Open Access Journals (Sweden)

Francisco Andrés Candelas

2011-05-01

Full Text Available This paper introduces a new set of compact interactive simulations developed for the constructive learning of computer networks concepts. These simulations, which compose a virtual laboratory implemented as portable Java applets, have been created by combining EJS (Easy Java Simulations with the KivaNS API. Furthermore, in this work, the skills and motivation level acquired by the students are evaluated and measured when these simulations are combined with Moodle and SCORM (Sharable Content Object Reference Model documents. This study has been developed to improve and stimulate the autonomous constructive learning in addition to provide timetable flexibility for a Computer Networks subject.

Social-Cognitive Biases in Simulated Airline Luggage Screening

Science.gov (United States)

Brown, Jeremy R.; Madhavan, Poomima

2011-01-01

This study illustrated how social cognitive biases affect the decision making process of air1ine luggage screeners. Participants (n = 96) performed a computer simulated task to detect hidden weapons in 200 x-ray images of passenger luggage. Participants saw each image for two (high time pressure) or six seconds (low time pressure). Participants observed pictures of the "passenger" who owns the luggage . The "pre-anchor group" answered questions about the passenger before the luggage image appeared, the "post-snchor" group answered questions after the luggage appeared, and the "no-anchor group" answered no questions. Participants either stopped or did not stop the bag. and rated their confidence in their decision. Participants under high time pressure had lower hit rates and higher false alarms, Significant differences between the pre-, no-, and post-anchor groups were based on the gender and race of the passengers. Participants had higher false alarm rates in response to male than female passengers.

Computer Simulation of Angle-measuring System of Photoelectric Theodolite

International Nuclear Information System (INIS)

Zeng, L; Zhao, Z W; Song, S L; Wang, L T

2006-01-01

In this paper, a virtual test platform based on malfunction phenomena is designed, using the methods of computer simulation and numerical mask. It is used in the simulation training of angle-measuring system of photoelectric theodolite. Actual application proves that this platform supplies good condition for technicians making deep simulation training and presents a useful approach for the establishment of other large equipment simulation platforms

THE SIMULATED SOCIAL-INTERACTION TEST - A PSYCHOMETRIC EVALUATION WITH DUTCH SOCIAL PHOBIC PATIENTS

NARCIS (Netherlands)

MERSCH, PPA; BREUKERS, P; EMMELKAMP, PMG

1992-01-01

The Simulated Social Interaction Test (SSIT) was translated and adjusted for use on a population of Dutch males and females. Seventy-four social phobic patients were assessed with the SSIT, a conversation test, and an interview with an independent observer. Results show that the SSIT is a relatively

Computing Resource And Work Allocations Using Social Profiles

Directory of Open Access Journals (Sweden)

Peter Lavin

2013-01-01

Full Text Available If several distributed and disparate computer resources exist, many of whichhave been created for different and diverse reasons, and several large scale com-puting challenges also exist with similar diversity in their backgrounds, then oneproblem which arises in trying to assemble enough of these resources to addresssuch challenges is the need to align and accommodate the different motivationsand objectives which may lie behind the existence of both the resources andthe challenges. Software agents are offered as a mainstream technology formodelling the types of collaborations and relationships needed to do this. Asan initial step towards forming such relationships, agents need a mechanism toconsider social and economic backgrounds. This paper explores addressing so-cial and economic differences using a combination of textual descriptions knownas social profiles and search engine technology, both of which are integrated intoan agent technology.

What do we want from computer simulation of SIMS using clusters?

International Nuclear Information System (INIS)

Webb, R.P.

2008-01-01

Computer simulation of energetic cluster interactions with surfaces has provided much needed insight into some of the complex processes which occur and are responsible for the desirable as well as undesirable effects which make the use of clusters in SIMS both useful and challenging. Simulations have shown how cluster impacts can cause meso-scale motion of the target material which can result in the relatively gentle up-lift of large intact molecules adsorbed on the surface in contrast to the behaviour of single atom impacts which tend to create discrete motion in the surface often ejecting fragments of adsorbed molecules instead. With the insight provided from simulations experimentalists can then improve their equipment to best maximise the desired effects. The past 40 years has seen great progress in simulation techniques and computer equipment. 40 years ago simulations were performed on simple atomic systems of around 300 atoms employing only simple pair-wise interaction potentials to times of several hundred femtoseconds. Currently simulations can be performed on large organic materials employing many body potentials for millions of atoms for times of many picoseconds. These simulations, however, can take several months of computation time. Even with the degree of realism introduced with these long time simulations they are still not perfect are often not capable of being used in a completely predictive way. Computer simulation is reaching a position where by any more effort to increase its realism will make it completely intractable to solution in a reasonable time frame and yet there is an increasing demand from experimentalists for something that can help in a predictive way to help in experiment design and interpretation. This paper will discuss the problems of computer simulation and what might be possible to achieve in the short term, what is unlikely ever to be possible without a major new break through and how we might exploit the meso-scale effects in

Parallel computing in enterprise modeling.

Energy Technology Data Exchange (ETDEWEB)

Goldsby, Michael E.; Armstrong, Robert C.; Shneider, Max S.; Vanderveen, Keith; Ray, Jaideep; Heath, Zach; Allan, Benjamin A.

2008-08-01

This report presents the results of our efforts to apply high-performance computing to entity-based simulations with a multi-use plugin for parallel computing. We use the term 'Entity-based simulation' to describe a class of simulation which includes both discrete event simulation and agent based simulation. What simulations of this class share, and what differs from more traditional models, is that the result sought is emergent from a large number of contributing entities. Logistic, economic and social simulations are members of this class where things or people are organized or self-organize to produce a solution. Entity-based problems never have an a priori ergodic principle that will greatly simplify calculations. Because the results of entity-based simulations can only be realized at scale, scalable computing is de rigueur for large problems. Having said that, the absence of a spatial organizing principal makes the decomposition of the problem onto processors problematic. In addition, practitioners in this domain commonly use the Java programming language which presents its own problems in a high-performance setting. The plugin we have developed, called the Parallel Particle Data Model, overcomes both of these obstacles and is now being used by two Sandia frameworks: the Decision Analysis Center, and the Seldon social simulation facility. While the ability to engage U.S.-sized problems is now available to the Decision Analysis Center, this plugin is central to the success of Seldon. Because Seldon relies on computationally intensive cognitive sub-models, this work is necessary to achieve the scale necessary for realistic results. With the recent upheavals in the financial markets, and the inscrutability of terrorist activity, this simulation domain will likely need a capability with ever greater fidelity. High-performance computing will play an important part in enabling that greater fidelity.

Validation and computing and performance studies for the ATLAS simulation

CERN Document Server

Marshall, Z; The ATLAS collaboration

2009-01-01

We present the validation of the ATLAS simulation software pro ject. Software development is controlled by nightly builds and several levels of automatic tests to ensure stability. Computing validation, including CPU time, memory, and disk space required per event, is benchmarked for all software releases. Several different physics processes and event types are checked to thoroughly test all aspects of the detector simulation. The robustness of the simulation software is demonstrated by the production of 500 million events on the World-wide LHC Computing Grid in the last year.

On efficiency of fire simulation realization: parallelization with greater number of computational meshes

Science.gov (United States)

Valasek, Lukas; Glasa, Jan

2017-12-01

Current fire simulation systems are capable to utilize advantages of high-performance computer (HPC) platforms available and to model fires efficiently in parallel. In this paper, efficiency of a corridor fire simulation on a HPC computer cluster is discussed. The parallel MPI version of Fire Dynamics Simulator is used for testing efficiency of selected strategies of allocation of computational resources of the cluster using a greater number of computational cores. Simulation results indicate that if the number of cores used is not equal to a multiple of the total number of cluster node cores there are allocation strategies which provide more efficient calculations.

Computational simulator of robotic manipulators

International Nuclear Information System (INIS)

Leal, Alexandre S.; Campos, Tarcisio P.R.

1995-01-01

Robotic application for industrial plants is discussed and a computational model for a mechanical manipulator of three links is presented. A neural network feed-forward type has been used to model the dynamic control of the manipulator. A graphic interface was developed in C programming language as a virtual world in order to visualize and simulate the arm movements handling radioactive waste environment. (author). 7 refs, 5 figs

Macromod: Computer Simulation For Introductory Economics

Science.gov (United States)

Ross, Thomas

1977-01-01

The Macroeconomic model (Macromod) is a computer assisted instruction simulation model designed for introductory economics courses. An evaluation of its utilization at a community college indicates that it yielded a 10 percent to 13 percent greater economic comprehension than lecture classes and that it met with high student approval. (DC)

An Investigation of Computer-based Simulations for School Crises Management.

Science.gov (United States)

Degnan, Edward; Bozeman, William

2001-01-01

Describes development of a computer-based simulation program for training school personnel in crisis management. Addresses the data collection and analysis involved in developing a simulated event, the systems requirements for simulation, and a case study of application and use of the completed simulation. (Contains 21 references.) (Authors/PKP)

The use of micro-computers in the simulation of ion beam optics

International Nuclear Information System (INIS)

Spaedtke, P.; Ivens, D.

1989-01-01

With computer simulation codes specific problems of the ion beam optics can be studied, which is useful in the design as in optimization of existing systems. Several such codes have been developed, unfortunately requiring substantial computer resources. Recent advances of mini- and micro-computers have now made it possible to develop simulation codes which can be run on these small computers also. In this paper, some of these codes will be presented and their computing time discussed. (author)

Computer simulation of driven Alfven waves

International Nuclear Information System (INIS)

Geary, J.L. Jr.

1986-01-01

The first particle simulation study of shear Alfven wave resonance heating is presented. Particle simulation codes self-consistently follow the time evolution of the individual and collective aspects of particle dynamics as well as wave dynamics in a fully nonlinear fashion. Alfven wave heating is a possible means of increasing the temperature of magnetized plasmas. A new particle simulation model was developed for this application that incorporates Darwin's formulation of the electromagnetic fields with a guiding center approximation for electron motion perpendicular to the ambient magnetic field. The implementation of this model and the examination of its theoretical and computational properties are presented. With this model, several cases of Alfven wave heating is examined in both uniform and nonuniform simulation systems in a two dimensional slab. For the inhomogeneous case studies, the kinetic Alfven wave develops in the vicinity of the shear Alfven resonance region

Man-machine interfaces analysis system based on computer simulation

International Nuclear Information System (INIS)

Chen Xiaoming; Gao Zuying; Zhou Zhiwei; Zhao Bingquan

2004-01-01

The paper depicts a software assessment system, Dynamic Interaction Analysis Support (DIAS), based on computer simulation technology for man-machine interfaces (MMI) of a control room. It employs a computer to simulate the operation procedures of operations on man-machine interfaces in a control room, provides quantified assessment, and at the same time carries out analysis on operational error rate of operators by means of techniques for human error rate prediction. The problems of placing man-machine interfaces in a control room and of arranging instruments can be detected from simulation results. DIAS system can provide good technical supports to the design and improvement of man-machine interfaces of the main control room of a nuclear power plant

Computational methods for coupling microstructural and micromechanical materials response simulations

Energy Technology Data Exchange (ETDEWEB)

HOLM,ELIZABETH A.; BATTAILE,CORBETT C.; BUCHHEIT,THOMAS E.; FANG,HUEI ELIOT; RINTOUL,MARK DANIEL; VEDULA,VENKATA R.; GLASS,S. JILL; KNOROVSKY,GERALD A.; NEILSEN,MICHAEL K.; WELLMAN,GERALD W.; SULSKY,DEBORAH; SHEN,YU-LIN; SCHREYER,H. BUCK

2000-04-01

Computational materials simulations have traditionally focused on individual phenomena: grain growth, crack propagation, plastic flow, etc. However, real materials behavior results from a complex interplay between phenomena. In this project, the authors explored methods for coupling mesoscale simulations of microstructural evolution and micromechanical response. In one case, massively parallel (MP) simulations for grain evolution and microcracking in alumina stronglink materials were dynamically coupled. In the other, codes for domain coarsening and plastic deformation in CuSi braze alloys were iteratively linked. this program provided the first comparison of two promising ways to integrate mesoscale computer codes. Coupled microstructural/micromechanical codes were applied to experimentally observed microstructures for the first time. In addition to the coupled codes, this project developed a suite of new computational capabilities (PARGRAIN, GLAD, OOF, MPM, polycrystal plasticity, front tracking). The problem of plasticity length scale in continuum calculations was recognized and a solution strategy was developed. The simulations were experimentally validated on stockpile materials.

Positive Wigner functions render classical simulation of quantum computation efficient.

Science.gov (United States)

Mari, A; Eisert, J

2012-12-07

We show that quantum circuits where the initial state and all the following quantum operations can be represented by positive Wigner functions can be classically efficiently simulated. This is true both for continuous-variable as well as discrete variable systems in odd prime dimensions, two cases which will be treated on entirely the same footing. Noting the fact that Clifford and Gaussian operations preserve the positivity of the Wigner function, our result generalizes the Gottesman-Knill theorem. Our algorithm provides a way of sampling from the output distribution of a computation or a simulation, including the efficient sampling from an approximate output distribution in the case of sampling imperfections for initial states, gates, or measurements. In this sense, this work highlights the role of the positive Wigner function as separating classically efficiently simulable systems from those that are potentially universal for quantum computing and simulation, and it emphasizes the role of negativity of the Wigner function as a computational resource.

Assessing Practical Skills in Physics Using Computer Simulations

Science.gov (United States)

Walsh, Kevin

2018-01-01

Computer simulations have been used very effectively for many years in the teaching of science but the focus has been on cognitive development. This study, however, is an investigation into the possibility that a student's experimental skills in the real-world environment can be judged via the undertaking of a suitably chosen computer simulation…

Yearning to Give Back: Searching for Social Purpose in Computer Science and Engineering.

Science.gov (United States)

Carrigan, Coleen M

2017-01-01

Computing is highly segregated and stratified by gender. While there is abundant scholarship investigating this problem, emerging evidence suggests that a hierarchy of value exists between the social and technical dimensions of Computer Science and Engineering (CSE) and this plays a role in the underrepresentation of women in the field. This ethnographic study of women's experiences in computing offers evidence of a systemic preference for the technical dimensions of computing over the social and a correlation between gender and social aspirations. Additionally, it suggests there is a gap between the exaltation of computing's social contributions and the realities of them. My participants expressed a yearning to contribute to the collective well-being of society using their computing skills. I trace moments of rupture in my participants' stories, moments when they felt these aspirations were in conflict with the cultural values in their organizations. I interpret these ruptures within a consideration of yearning, a need my participants had to contribute meaningfully to society that remained unfulfilled. The yearning to align one's altruistic values with one's careers aspirations in CSE illuminates an area for greater exploration on the path to realizing gender equity in computing. I argue that before a case can be made that careers in computing do indeed contribute to social and civil engagements, we must first address the meaning of the social within the values, ideologies and practices of CSE institutions and next, develop ways to measure and evaluate the field's contributions to society.

Computer simulation of stair falls to investigate scenarios in child abuse.

Science.gov (United States)

Bertocci, G E; Pierce, M C; Deemer, E; Aguel, F

2001-09-01

To demonstrate the usefulness of computer simulation techniques in the investigation of pediatric stair falls. Since stair falls are a common falsely reported injury scenario in child abuse, our specific aim was to investigate the influence of stair characteristics on injury biomechanics of pediatric stair falls by using a computer simulation model. Our long-term goal is to use knowledge of biomechanics to aid in distinguishing between accidents and abuse. A computer simulation model of a 3-year-old child falling down stairs was developed using commercially available simulation software. This model was used to investigate the influence that stair characteristics have on biomechanical measures associated with injury risk. Since femur fractures occur in unintentional and abuse scenarios, biomechanical measures were focused on the lower extremities. The number and slope of steps and stair surface friction and elasticity were found to affect biomechanical measures associated with injury risk. Computer simulation techniques are useful for investigating the biomechanics of stair falls. Using our simulation model, we determined that stair characteristics have an effect on potential for lower extremity injuries. Although absolute values of biomechanical measures should not be relied on in an unvalidated model such as this, relationships between accident-environment factors and biomechanical measures can be studied through simulation. Future efforts will focus on model validation.

Evaluation of Rankine cycle air conditioning system hardware by computer simulation

Science.gov (United States)

Healey, H. M.; Clark, D.

1978-01-01

A computer program for simulating the performance of a variety of solar powered Rankine cycle air conditioning system components (RCACS) has been developed. The computer program models actual equipment by developing performance maps from manufacturers data and is capable of simulating off-design operation of the RCACS components. The program designed to be a subroutine of the Marshall Space Flight Center (MSFC) Solar Energy System Analysis Computer Program 'SOLRAD', is a complete package suitable for use by an occasional computer user in developing performance maps of heating, ventilation and air conditioning components.

The TeraShake Computational Platform for Large-Scale Earthquake Simulations

Science.gov (United States)

Cui, Yifeng; Olsen, Kim; Chourasia, Amit; Moore, Reagan; Maechling, Philip; Jordan, Thomas

Geoscientific and computer science researchers with the Southern California Earthquake Center (SCEC) are conducting a large-scale, physics-based, computationally demanding earthquake system science research program with the goal of developing predictive models of earthquake processes. The computational demands of this program continue to increase rapidly as these researchers seek to perform physics-based numerical simulations of earthquake processes for larger meet the needs of this research program, a multiple-institution team coordinated by SCEC has integrated several scientific codes into a numerical modeling-based research tool we call the TeraShake computational platform (TSCP). A central component in the TSCP is a highly scalable earthquake wave propagation simulation program called the TeraShake anelastic wave propagation (TS-AWP) code. In this chapter, we describe how we extended an existing, stand-alone, wellvalidated, finite-difference, anelastic wave propagation modeling code into the highly scalable and widely used TS-AWP and then integrated this code into the TeraShake computational platform that provides end-to-end (initialization to analysis) research capabilities. We also describe the techniques used to enhance the TS-AWP parallel performance on TeraGrid supercomputers, as well as the TeraShake simulations phases including input preparation, run time, data archive management, and visualization. As a result of our efforts to improve its parallel efficiency, the TS-AWP has now shown highly efficient strong scaling on over 40K processors on IBM’s BlueGene/L Watson computer. In addition, the TSCP has developed into a computational system that is useful to many members of the SCEC community for performing large-scale earthquake simulations.

Bibliography for Verification and Validation in Computational Simulation

International Nuclear Information System (INIS)

Oberkampf, W.L.

1998-01-01

A bibliography has been compiled dealing with the verification and validation of computational simulations. The references listed in this bibliography are concentrated in the field of computational fluid dynamics (CFD). However, references from the following fields are also included: operations research, heat transfer, solid dynamics, software quality assurance, software accreditation, military systems, and nuclear reactor safety. This bibliography, containing 221 references, is not meant to be comprehensive. It was compiled during the last ten years in response to the author's interest and research in the methodology for verification and validation. The emphasis in the bibliography is in the following areas: philosophy of science underpinnings, development of terminology and methodology, high accuracy solutions for CFD verification, experimental datasets for CFD validation, and the statistical quantification of model validation. This bibliography should provide a starting point for individual researchers in many fields of computational simulation in science and engineering

Bibliography for Verification and Validation in Computational Simulations

Energy Technology Data Exchange (ETDEWEB)

Oberkampf, W.L.

1998-10-01

A bibliography has been compiled dealing with the verification and validation of computational simulations. The references listed in this bibliography are concentrated in the field of computational fluid dynamics (CFD). However, references from the following fields are also included: operations research, heat transfer, solid dynamics, software quality assurance, software accreditation, military systems, and nuclear reactor safety. This bibliography, containing 221 references, is not meant to be comprehensive. It was compiled during the last ten years in response to the author's interest and research in the methodology for verification and validation. The emphasis in the bibliography is in the following areas: philosophy of science underpinnings, development of terminology and methodology, high accuracy solutions for CFD verification, experimental datasets for CFD validation, and the statistical quantification of model validation. This bibliography should provide a starting point for individual researchers in many fields of computational simulation in science and engineering.

Computer Simulation Surgery for Mandibular Reconstruction Using a Fibular Osteotomy Guide

Directory of Open Access Journals (Sweden)

Woo Shik Jeong

2014-09-01

Full Text Available In the present study, a fibular osteotomy guide based on a computer simulation was applied to a patient who had undergone mandibular segmental ostectomy due to oncological complications. This patient was a 68-year-old woman who presented to our department with a biopsy-proven squamous cell carcinoma on her left gingival area. This lesion had destroyed the cortical bony structure, and the patient showed attenuation of her soft tissue along the inferior alveolar nerve, indicating perineural spread of the tumor. Prior to surgery, a three-dimensional computed tomography scan of the facial and fibular bones was performed. We then created a virtual computer simulation of the mandibular segmental defect through which we segmented the fibular to reconstruct the proper angulation in the original mandible. Approximately 2-cm segments were created on the basis of this simulation and applied to the virtually simulated mandibular segmental defect. Thus, we obtained a virtual model of the ideal mandibular reconstruction for this patient with a fibular free flap. We could then use this computer simulation for the subsequent surgery and minimize the bony gaps between the multiple fibular bony segments.

SNOW: a digital computer program for the simulation of ion beam devices

International Nuclear Information System (INIS)

Boers, J.E.

1980-08-01

A digital computer program, SNOW, has been developed for the simulation of dense ion beams. The program simulates the plasma expansion cup (but not the plasma source itself), the acceleration region, and a drift space with neutralization if desired. The ion beam is simulated by computing representative trajectories through the device. The potentials are simulated on a large rectangular matrix array which is solved by iterative techniques. Poisson's equation is solved at each point within the configuration using space-charge densities computed from the ion trajectories combined with background electron and/or ion distributions. The simulation methods are described in some detail along with examples of both axially-symmetric and rectangular beams. A detailed description of the input data is presented

Large Atmospheric Computation on the Earth Simulator: The LACES Project

Directory of Open Access Journals (Sweden)

Michel Desgagné

2006-01-01

Full Text Available The Large Atmospheric Computation on the Earth Simulator (LACES project is a joint initiative between Canadian and Japanese meteorological services and academic institutions that focuses on the high resolution simulation of Hurricane Earl (1998. The unique aspect of this effort is the extent of the computational domain, which covers all of North America and Europe with a grid spacing of 1 km. The Canadian Mesoscale Compressible Community (MC2 model is shown to parallelize effectively on the Japanese Earth Simulator (ES supercomputer; however, even using the extensive computing resources of the ES Center (ESC, the full simulation for the majority of Hurricane Earl's lifecycle takes over eight days to perform and produces over 5.2 TB of raw data. Preliminary diagnostics show that the results of the LACES simulation for the tropical stage of Hurricane Earl's lifecycle compare well with available observations for the storm. Further studies involving advanced diagnostics have commenced, taking advantage of the uniquely large spatial extent of the high resolution LACES simulation to investigate multiscale interactions in the hurricane and its environment. It is hoped that these studies will enhance our understanding of processes occurring within the hurricane and between the hurricane and its planetary-scale environment.

AN EVALUATION AND IMPLEMENTATION OF COLLABORATIVE AND SOCIAL NETWORKING TECHNOLOGIES FOR COMPUTER EDUCATION

OpenAIRE

Ronnie Cheung; Calvin Wan

2011-01-01

We have developed a collaborative and social networking environment that integrates the knowledge and skills in communication and computing studies with a multimedia development project. The outcomes of the students’ projects show that computer literacy can be enhanced through a cluster of communication, social, and digital skills. Experience in implementing a web-based social networking environment shows that the new media is an effective means of enriching knowledge by sharing in computer l...

Extremely Scalable Spiking Neuronal Network Simulation Code: From Laptops to Exascale Computers

Science.gov (United States)

Jordan, Jakob; Ippen, Tammo; Helias, Moritz; Kitayama, Itaru; Sato, Mitsuhisa; Igarashi, Jun; Diesmann, Markus; Kunkel, Susanne

2018-01-01

State-of-the-art software tools for neuronal network simulations scale to the largest computing systems available today and enable investigations of large-scale networks of up to 10 % of the human cortex at a resolution of individual neurons and synapses. Due to an upper limit on the number of incoming connections of a single neuron, network connectivity becomes extremely sparse at this scale. To manage computational costs, simulation software ultimately targeting the brain scale needs to fully exploit this sparsity. Here we present a two-tier connection infrastructure and a framework for directed communication among compute nodes accounting for the sparsity of brain-scale networks. We demonstrate the feasibility of this approach by implementing the technology in the NEST simulation code and we investigate its performance in different scaling scenarios of typical network simulations. Our results show that the new data structures and communication scheme prepare the simulation kernel for post-petascale high-performance computing facilities without sacrificing performance in smaller systems. PMID:29503613

Extremely Scalable Spiking Neuronal Network Simulation Code: From Laptops to Exascale Computers.

Science.gov (United States)

Jordan, Jakob; Ippen, Tammo; Helias, Moritz; Kitayama, Itaru; Sato, Mitsuhisa; Igarashi, Jun; Diesmann, Markus; Kunkel, Susanne

2018-01-01

State-of-the-art software tools for neuronal network simulations scale to the largest computing systems available today and enable investigations of large-scale networks of up to 10 % of the human cortex at a resolution of individual neurons and synapses. Due to an upper limit on the number of incoming connections of a single neuron, network connectivity becomes extremely sparse at this scale. To manage computational costs, simulation software ultimately targeting the brain scale needs to fully exploit this sparsity. Here we present a two-tier connection infrastructure and a framework for directed communication among compute nodes accounting for the sparsity of brain-scale networks. We demonstrate the feasibility of this approach by implementing the technology in the NEST simulation code and we investigate its performance in different scaling scenarios of typical network simulations. Our results show that the new data structures and communication scheme prepare the simulation kernel for post-petascale high-performance computing facilities without sacrificing performance in smaller systems.

Extremely Scalable Spiking Neuronal Network Simulation Code: From Laptops to Exascale Computers

Directory of Open Access Journals (Sweden)

Jakob Jordan

2018-02-01

Full Text Available State-of-the-art software tools for neuronal network simulations scale to the largest computing systems available today and enable investigations of large-scale networks of up to 10 % of the human cortex at a resolution of individual neurons and synapses. Due to an upper limit on the number of incoming connections of a single neuron, network connectivity becomes extremely sparse at this scale. To manage computational costs, simulation software ultimately targeting the brain scale needs to fully exploit this sparsity. Here we present a two-tier connection infrastructure and a framework for directed communication among compute nodes accounting for the sparsity of brain-scale networks. We demonstrate the feasibility of this approach by implementing the technology in the NEST simulation code and we investigate its performance in different scaling scenarios of typical network simulations. Our results show that the new data structures and communication scheme prepare the simulation kernel for post-petascale high-performance computing facilities without sacrificing performance in smaller systems.

Computer simulation of fatigue under diametrical compression

OpenAIRE

Carmona, H. A.; Kun, F.; Andrade Jr., J. S.; Herrmann, H. J.

2006-01-01

We study the fatigue fracture of disordered materials by means of computer simulations of a discrete element model. We extend a two-dimensional fracture model to capture the microscopic mechanisms relevant for fatigue, and we simulate the diametric compression of a disc shape specimen under a constant external force. The model allows to follow the development of the fracture process on the macro- and micro-level varying the relative influence of the mechanisms of damage accumulation over the ...

Computer simulations and the changing face of scientific experimentation

CERN Document Server

Duran, Juan M

2013-01-01

Computer simulations have become a central tool for scientific practice. Their use has replaced, in many cases, standard experimental procedures. This goes without mentioning cases where the target system is empirical but there are no techniques for direct manipulation of the system, such as astronomical observation. To these cases, computer simulations have proved to be of central importance. The question about their use and implementation, therefore, is not only a technical one but represents a challenge for the humanities as well. In this volume, scientists, historians, and philosophers joi

A Computational Framework for Bioimaging Simulation

Science.gov (United States)

Watabe, Masaki; Arjunan, Satya N. V.; Fukushima, Seiya; Iwamoto, Kazunari; Kozuka, Jun; Matsuoka, Satomi; Shindo, Yuki; Ueda, Masahiro; Takahashi, Koichi

2015-01-01

Using bioimaging technology, biologists have attempted to identify and document analytical interpretations that underlie biological phenomena in biological cells. Theoretical biology aims at distilling those interpretations into knowledge in the mathematical form of biochemical reaction networks and understanding how higher level functions emerge from the combined action of biomolecules. However, there still remain formidable challenges in bridging the gap between bioimaging and mathematical modeling. Generally, measurements using fluorescence microscopy systems are influenced by systematic effects that arise from stochastic nature of biological cells, the imaging apparatus, and optical physics. Such systematic effects are always present in all bioimaging systems and hinder quantitative comparison between the cell model and bioimages. Computational tools for such a comparison are still unavailable. Thus, in this work, we present a computational framework for handling the parameters of the cell models and the optical physics governing bioimaging systems. Simulation using this framework can generate digital images of cell simulation results after accounting for the systematic effects. We then demonstrate that such a framework enables comparison at the level of photon-counting units. PMID:26147508

A Computational Framework for Bioimaging Simulation.

Science.gov (United States)

Watabe, Masaki; Arjunan, Satya N V; Fukushima, Seiya; Iwamoto, Kazunari; Kozuka, Jun; Matsuoka, Satomi; Shindo, Yuki; Ueda, Masahiro; Takahashi, Koichi

2015-01-01

Using bioimaging technology, biologists have attempted to identify and document analytical interpretations that underlie biological phenomena in biological cells. Theoretical biology aims at distilling those interpretations into knowledge in the mathematical form of biochemical reaction networks and understanding how higher level functions emerge from the combined action of biomolecules. However, there still remain formidable challenges in bridging the gap between bioimaging and mathematical modeling. Generally, measurements using fluorescence microscopy systems are influenced by systematic effects that arise from stochastic nature of biological cells, the imaging apparatus, and optical physics. Such systematic effects are always present in all bioimaging systems and hinder quantitative comparison between the cell model and bioimages. Computational tools for such a comparison are still unavailable. Thus, in this work, we present a computational framework for handling the parameters of the cell models and the optical physics governing bioimaging systems. Simulation using this framework can generate digital images of cell simulation results after accounting for the systematic effects. We then demonstrate that such a framework enables comparison at the level of photon-counting units.

A Computational Framework for Bioimaging Simulation.

Directory of Open Access Journals (Sweden)

Masaki Watabe

Full Text Available Using bioimaging technology, biologists have attempted to identify and document analytical interpretations that underlie biological phenomena in biological cells. Theoretical biology aims at distilling those interpretations into knowledge in the mathematical form of biochemical reaction networks and understanding how higher level functions emerge from the combined action of biomolecules. However, there still remain formidable challenges in bridging the gap between bioimaging and mathematical modeling. Generally, measurements using fluorescence microscopy systems are influenced by systematic effects that arise from stochastic nature of biological cells, the imaging apparatus, and optical physics. Such systematic effects are always present in all bioimaging systems and hinder quantitative comparison between the cell model and bioimages. Computational tools for such a comparison are still unavailable. Thus, in this work, we present a computational framework for handling the parameters of the cell models and the optical physics governing bioimaging systems. Simulation using this framework can generate digital images of cell simulation results after accounting for the systematic effects. We then demonstrate that such a framework enables comparison at the level of photon-counting units.

Bridging Social and Semantic Computing - Design and Evaluation of User Interfaces for Hybrid Systems

Science.gov (United States)

Bostandjiev, Svetlin Alex I.

2012-01-01

The evolution of the Web brought new interesting problems to computer scientists that we loosely classify in the fields of social and semantic computing. Social computing is related to two major paradigms: computations carried out by a large amount of people in a collective intelligence fashion (i.e. wikis), and performing computations on social…

simulate_CAT: A Computer Program for Post-Hoc Simulation for Computerized Adaptive Testing

Directory of Open Access Journals (Sweden)

İlker Kalender

2015-06-01

Full Text Available This paper presents a computer software developed by the author. The software conducts post-hoc simulations for computerized adaptive testing based on real responses of examinees to paper and pencil tests under different parameters that can be defined by user. In this paper, short information is given about post-hoc simulations. After that, the working principle of the software is provided and a sample simulation with required input files is shown. And last, output files are described

The challenge of quantum computer simulations of physical phenomena

International Nuclear Information System (INIS)

Ortiz, G.; Knill, E.; Gubernatis, J.E.

2002-01-01

The goal of physics simulation using controllable quantum systems ('physics imitation') is to exploit quantum laws to advantage, and thus accomplish efficient simulation of physical phenomena. In this Note, we discuss the fundamental concepts behind this paradigm of information processing, such as the connection between models of computation and physical systems. The experimental simulation of a toy quantum many-body problem is described

High performance stream computing for particle beam transport simulations

International Nuclear Information System (INIS)

Appleby, R; Bailey, D; Higham, J; Salt, M

2008-01-01

Understanding modern particle accelerators requires simulating charged particle transport through the machine elements. These simulations can be very time consuming due to the large number of particles and the need to consider many turns of a circular machine. Stream computing offers an attractive way to dramatically improve the performance of such simulations by calculating the simultaneous transport of many particles using dedicated hardware. Modern Graphics Processing Units (GPUs) are powerful and affordable stream computing devices. The results of simulations of particle transport through the booster-to-storage-ring transfer line of the DIAMOND synchrotron light source using an NVidia GeForce 7900 GPU are compared to the standard transport code MAD. It is found that particle transport calculations are suitable for stream processing and large performance increases are possible. The accuracy and potential speed gains are compared and the prospects for future work in the area are discussed

Computer simulation of variform fuel assemblies using Dragon code

International Nuclear Information System (INIS)

Ju Haitao; Wu Hongchun; Yao Dong

2005-01-01

The DRAGON is a cell code that developed for the CANDU reactor by the Ecole Polytechnique de Montreal of CANADA. Although, the DRAGON is mainly used to simulate the CANDU super-cell fuel assembly, it has an ability to simulate other geometries of the fuel assembly. However, only NEACRP benchmark problem of the BWR lattice cell was analyzed until now except for the CANDU reactor. We also need to develop the code to simulate the variform fuel assemblies, especially, for design of the advanced reactor. We validated that the cell code DRAGON is useful for simulating various kinds of the fuel assembly by analyzing the rod-shape fuel assembly of the PWR and the MTR plate-shape fuel assembly. Some other kinds of geometry of geometry were computed. Computational results show that the DRAGON is able to analyze variform fuel assembly problems and the precision is high. (authors)

Teaching Computer Organization and Architecture Using Simulation and FPGA Applications

OpenAIRE

D. K.M. Al-Aubidy

2007-01-01

This paper presents the design concepts and realization of incorporating micro-operation simulation and FPGA implementation into a teaching tool for computer organization and architecture. This teaching tool helps computer engineering and computer science students to be familiarized practically with computer organization and architecture through the development of their own instruction set, computer programming and interfacing experiments. A two-pass assembler has been designed and implemente...

An introduction to computer simulation methods applications to physical systems

CERN Document Server

Gould, Harvey; Christian, Wolfgang

2007-01-01

Now in its third edition, this book teaches physical concepts using computer simulations. The text incorporates object-oriented programming techniques and encourages readers to develop good programming habits in the context of doing physics. Designed for readers at all levels , An Introduction to Computer Simulation Methods uses Java, currently the most popular programming language. Introduction, Tools for Doing Simulations, Simulating Particle Motion, Oscillatory Systems, Few-Body Problems: The Motion of the Planets, The Chaotic Motion of Dynamical Systems, Random Processes, The Dynamics of Many Particle Systems, Normal Modes and Waves, Electrodynamics, Numerical and Monte Carlo Methods, Percolation, Fractals and Kinetic Growth Models, Complex Systems, Monte Carlo Simulations of Thermal Systems, Quantum Systems, Visualization and Rigid Body Dynamics, Seeing in Special and General Relativity, Epilogue: The Unity of Physics For all readers interested in developing programming habits in the context of doing phy...

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

Directory of Open Access Journals (Sweden)

Qiang Liu

2018-05-01

Full Text Available Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal computer, a Graphics Processing Unit (GPU-based, high-performance computing method using the OpenACC application was adopted to parallelize the shallow water model. An unstructured data management method was presented to control the data transportation between the GPU and CPU (Central Processing Unit with minimum overhead, and then both computation and data were offloaded from the CPU to the GPU, which exploited the computational capability of the GPU as much as possible. The parallel model was validated using various benchmarks and real-world case studies. The results demonstrate that speed-ups of up to one order of magnitude can be achieved in comparison with the serial model. The proposed parallel model provides a fast and reliable tool with which to quickly assess flood hazards in large-scale areas and, thus, has a bright application prospect for dynamic inundation risk identification and disaster assessment.

Refining Pragmatically-Appropriate Oral Communication via Computer-Simulated Conversations

Science.gov (United States)

Sydorenko, Tetyana; Daurio, Phoebe; Thorne, Steven L.

2018-01-01

To address the problem of limited opportunities for practicing second language speaking in interaction, especially delicate interactions requiring pragmatic competence, we describe computer simulations designed for the oral practice of extended pragmatic routines and report on the affordances of such simulations for learning pragmatically…

Simulation of quantum computation : A deterministic event-based approach

NARCIS (Netherlands)

Michielsen, K; De Raedt, K; De Raedt, H

We demonstrate that locally connected networks of machines that have primitive learning capabilities can be used to perform a deterministic, event-based simulation of quantum computation. We present simulation results for basic quantum operations such as the Hadamard and the controlled-NOT gate, and

Simulation of Quantum Computation : A Deterministic Event-Based Approach

NARCIS (Netherlands)

Michielsen, K.; Raedt, K. De; Raedt, H. De

2005-01-01

We demonstrate that locally connected networks of machines that have primitive learning capabilities can be used to perform a deterministic, event-based simulation of quantum computation. We present simulation results for basic quantum operations such as the Hadamard and the controlled-NOT gate, and

Computer Simulation of the Relationship between Selected Properties of PVD Coatings

Directory of Open Access Journals (Sweden)

Śliwa A.

2016-06-01

Full Text Available The possibility to apply the Finite Element Method to calculate internal stresses which occur in Ti+TiN, Ti+Ti(CxN1-x and Ti+TiC coatings obtained in the magnetron PVD process on the sintered high-speed steel of the PM HS6-5-3-8 type. For the purpose of computer simulation of internal stresses in coatings with the use of MES, the correct model of analyzed specimens was worked out and then it was experimentally verified by comparison of calculation results with the results of computer simulation. Accurate analysis of correlations indicated especially strong dependence between internal stresses and microhardness and between microhardness and erosion resistance what created conditions for establishing the dependence between internal stresses obtained in the result of computer simulation and erosion resistance as basic functional quality of coating. It has essential practical meaning because it allows to estimate predictable erosion resistance of coating exclusively on the base of the results of computer simulation for used parameters in the process of coating manufacturing.

Comparison of real and computer-simulated outcomes of LASIK refractive surgery

Science.gov (United States)

Cano, Daniel; Barbero, Sergio; Marcos, Susana

2004-06-01

Computer simulations of alternative LASIK ablation patterns were performed for corneal elevation maps of 13 real myopic corneas (range of myopia, -2.0 to -11.5 D). The computationally simulated ablation patterns were designed with biconic surfaces (standard Munnerlyn pattern, parabolic pattern, and biconic pattern) or with aberrometry measurements (customized pattern). Simulated results were compared with real postoperative outcomes. Standard LASIK refractive surgery for myopia increased corneal asphericity and spherical aberration. Computations with the theoretical Munnerlyn ablation pattern did not increase the corneal asphericity and spherical aberration. The theoretical parabolic pattern induced a slight increase of asphericity and spherical aberration, explaining only 40% of the clinically found increase. The theoretical biconic pattern controlled corneal spherical aberration. Computations showed that the theoretical customized pattern can correct high-order asymmetric aberrations. Simulations of changes in efficiency due to reflection and nonnormal incidence of the laser light showed a further increase in corneal asphericity. Consideration of these effects with a parabolic pattern accounts for 70% of the clinical increase in asphericity.

Social sciences via network analysis and computation

CERN Document Server

Kanduc, Tadej

2015-01-01

In recent years information and communication technologies have gained significant importance in the social sciences. Because there is such rapid growth of knowledge, methods and computer infrastructure, research can now seamlessly connect interdisciplinary fields such as business process management, data processing and mathematics. This study presents some of the latest results, practices and state-of-the-art approaches in network analysis, machine learning, data mining, data clustering and classifications in the contents of social sciences. It also covers various real-life examples such as t

Use of computer simulations for the early introduction of nuclear engineering concepts

International Nuclear Information System (INIS)

Ougouag, A.M.; Zerguini, T.H.

1985-01-01

A sophomore level nuclear engineering (NE) course is being introduced at the University of Illinois. Via computer simulations, this course presents materials covering the most important aspects of the field. It is noted that computer simulations in nuclear engineering are cheaper and safer than experiments yet they provide an effective teaching tool for the early introduction of advanced concepts. The new course material can be used as a tutorial and for remedial learning. The use of computer simulation motivates learning since students associate computer activities with games. Such a course can help in the dissemination of the proper information to students from different fields, including liberal arts, and eventually increase undergraduate student enrollment in nuclear engineering

Analysis and modeling of social influence in high performance computing workloads

KAUST Repository

Zheng, Shuai

2011-01-01

Social influence among users (e.g., collaboration on a project) creates bursty behavior in the underlying high performance computing (HPC) workloads. Using representative HPC and cluster workload logs, this paper identifies, analyzes, and quantifies the level of social influence across HPC users. We show the existence of a social graph that is characterized by a pattern of dominant users and followers. This pattern also follows a power-law distribution, which is consistent with those observed in mainstream social networks. Given its potential impact on HPC workloads prediction and scheduling, we propose a fast-converging, computationally-efficient online learning algorithm for identifying social groups. Extensive evaluation shows that our online algorithm can (1) quickly identify the social relationships by using a small portion of incoming jobs and (2) can efficiently track group evolution over time. © 2011 Springer-Verlag.

Analyzing, Modeling, and Simulation for Human Dynamics in Social Network

Directory of Open Access Journals (Sweden)

Yunpeng Xiao

2012-01-01

Full Text Available This paper studies the human behavior in the top-one social network system in China (Sina Microblog system. By analyzing real-life data at a large scale, we find that the message releasing interval (intermessage time obeys power law distribution both at individual level and at group level. Statistical analysis also reveals that human behavior in social network is mainly driven by four basic elements: social pressure, social identity, social participation, and social relation between individuals. Empirical results present the four elements' impact on the human behavior and the relation between these elements. To further understand the mechanism of such dynamic phenomena, a hybrid human dynamic model which combines “interest” of individual and “interaction” among people is introduced, incorporating the four elements simultaneously. To provide a solid evaluation, we simulate both two-agent and multiagent interactions with real-life social network topology. We achieve the consistent results between empirical studies and the simulations. The model can provide a good understanding of human dynamics in social network.

Computer Hacking as a Social Problem

OpenAIRE

Alleyne, Brian

2018-01-01

This chapter introduces the ideas and practices of digital technology enthusiasts who fall under the umbrella of “hackers. “We will discuss how their defining activity has been constructed as a social problem and how that construction has been challenged in different ways. The chapter concludes with several policy suggestions aimed at addressing the more problematic aspects of computer hacking.

Comprehensive Simulation Lifecycle Management for High Performance Computing Modeling and Simulation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — There are significant logistical barriers to entry-level high performance computing (HPC) modeling and simulation (M IllinoisRocstar) sets up the infrastructure for...

Implementation of Grid-computing Framework for Simulation in Multi-scale Structural Analysis

Directory of Open Access Journals (Sweden)

Data Iranata

2010-05-01

Full Text Available A new grid-computing framework for simulation in multi-scale structural analysis is presented. Two levels of parallel processing will be involved in this framework: multiple local distributed computing environments connected by local network to form a grid-based cluster-to-cluster distributed computing environment. To successfully perform the simulation, a large-scale structural system task is decomposed into the simulations of a simplified global model and several detailed component models using various scales. These correlated multi-scale structural system tasks are distributed among clusters and connected together in a multi-level hierarchy and then coordinated over the internet. The software framework for supporting the multi-scale structural simulation approach is also presented. The program architecture design allows the integration of several multi-scale models as clients and servers under a single platform. To check its feasibility, a prototype software system has been designed and implemented to perform the proposed concept. The simulation results show that the software framework can increase the speedup performance of the structural analysis. Based on this result, the proposed grid-computing framework is suitable to perform the simulation of the multi-scale structural analysis.

Plant Closings and Capital Flight: A Computer-Assisted Simulation.

Science.gov (United States)

Warner, Stanley; Breitbart, Myrna M.

1989-01-01

A course at Hampshire College was designed to simulate the decision-making environment in which constituencies in a medium-sized city would respond to the closing and relocation of a major corporate plant. The project, constructed as a role simulation with a computer component, is described. (MLW)

SU-E-T-222: Computational Optimization of Monte Carlo Simulation On 4D Treatment Planning Using the Cloud Computing Technology

International Nuclear Information System (INIS)

Chow, J

2015-01-01

Purpose: This study evaluated the efficiency of 4D lung radiation treatment planning using Monte Carlo simulation on the cloud. The EGSnrc Monte Carlo code was used in dose calculation on the 4D-CT image set. Methods: 4D lung radiation treatment plan was created by the DOSCTP linked to the cloud, based on the Amazon elastic compute cloud platform. Dose calculation was carried out by Monte Carlo simulation on the 4D-CT image set on the cloud, and results were sent to the FFD4D image deformation program for dose reconstruction. The dependence of computing time for treatment plan on the number of compute node was optimized with variations of the number of CT image set in the breathing cycle and dose reconstruction time of the FFD4D. Results: It is found that the dependence of computing time on the number of compute node was affected by the diminishing return of the number of node used in Monte Carlo simulation. Moreover, the performance of the 4D treatment planning could be optimized by using smaller than 10 compute nodes on the cloud. The effects of the number of image set and dose reconstruction time on the dependence of computing time on the number of node were not significant, as more than 15 compute nodes were used in Monte Carlo simulations. Conclusion: The issue of long computing time in 4D treatment plan, requiring Monte Carlo dose calculations in all CT image sets in the breathing cycle, can be solved using the cloud computing technology. It is concluded that the optimized number of compute node selected in simulation should be between 5 and 15, as the dependence of computing time on the number of node is significant

SU-E-T-222: Computational Optimization of Monte Carlo Simulation On 4D Treatment Planning Using the Cloud Computing Technology

Energy Technology Data Exchange (ETDEWEB)

Chow, J [Princess Margaret Cancer Center, Toronto, ON (Canada)

2015-06-15

Purpose: This study evaluated the efficiency of 4D lung radiation treatment planning using Monte Carlo simulation on the cloud. The EGSnrc Monte Carlo code was used in dose calculation on the 4D-CT image set. Methods: 4D lung radiation treatment plan was created by the DOSCTP linked to the cloud, based on the Amazon elastic compute cloud platform. Dose calculation was carried out by Monte Carlo simulation on the 4D-CT image set on the cloud, and results were sent to the FFD4D image deformation program for dose reconstruction. The dependence of computing time for treatment plan on the number of compute node was optimized with variations of the number of CT image set in the breathing cycle and dose reconstruction time of the FFD4D. Results: It is found that the dependence of computing time on the number of compute node was affected by the diminishing return of the number of node used in Monte Carlo simulation. Moreover, the performance of the 4D treatment planning could be optimized by using smaller than 10 compute nodes on the cloud. The effects of the number of image set and dose reconstruction time on the dependence of computing time on the number of node were not significant, as more than 15 compute nodes were used in Monte Carlo simulations. Conclusion: The issue of long computing time in 4D treatment plan, requiring Monte Carlo dose calculations in all CT image sets in the breathing cycle, can be solved using the cloud computing technology. It is concluded that the optimized number of compute node selected in simulation should be between 5 and 15, as the dependence of computing time on the number of node is significant.

Computational plasticity algorithm for particle dynamics simulations

Science.gov (United States)

Krabbenhoft, K.; Lyamin, A. V.; Vignes, C.

2018-01-01

The problem of particle dynamics simulation is interpreted in the framework of computational plasticity leading to an algorithm which is mathematically indistinguishable from the common implicit scheme widely used in the finite element analysis of elastoplastic boundary value problems. This algorithm provides somewhat of a unification of two particle methods, the discrete element method and the contact dynamics method, which usually are thought of as being quite disparate. In particular, it is shown that the former appears as the special case where the time stepping is explicit while the use of implicit time stepping leads to the kind of schemes usually labelled contact dynamics methods. The framing of particle dynamics simulation within computational plasticity paves the way for new approaches similar (or identical) to those frequently employed in nonlinear finite element analysis. These include mixed implicit-explicit time stepping, dynamic relaxation and domain decomposition schemes.

Functional requirements for design of the Space Ultrareliable Modular Computer (SUMC) system simulator

Science.gov (United States)

Curran, R. T.; Hornfeck, W. A.

1972-01-01

The functional requirements for the design of an interpretive simulator for the space ultrareliable modular computer (SUMC) are presented. A review of applicable existing computer simulations is included along with constraints on the SUMC simulator functional design. Input requirements, output requirements, and language requirements for the simulator are discussed in terms of a SUMC configuration which may vary according to the application.

Topics in computer simulations of statistical systems

International Nuclear Information System (INIS)

Salvador, R.S.

1987-01-01

Several computer simulations studying a variety of topics in statistical mechanics and lattice gauge theories are performed. The first study describes a Monte Carlo simulation performed on Ising systems defined on Sierpinsky carpets of dimensions between one and four. The critical coupling and the exponent γ are measured as a function of dimension. The Ising gauge theory in d = 4 - epsilon, for epsilon → 0 + , is then studied by performing a Monte Carlo simulation for the theory defined on fractals. A high statistics Monte Carlo simulation for the three-dimensional Ising model is presented for lattices of sizes 8 3 to 44 3 . All the data obtained agrees completely, within statistical errors, with the forms predicted by finite-sizing scaling. Finally, a method to estimate numerically the partition function of statistical systems is developed

A computer simulation model to compute the radiation transfer of mountainous regions

Science.gov (United States)

Li, Yuguang; Zhao, Feng; Song, Rui

2011-11-01

In mountainous regions, the radiometric signal recorded at the sensor depends on a number of factors such as sun angle, atmospheric conditions, surface cover type, and topography. In this paper, a computer simulation model of radiation transfer is designed and evaluated. This model implements the Monte Carlo ray-tracing techniques and is specifically dedicated to the study of light propagation in mountainous regions. The radiative processes between sun light and the objects within the mountainous region are realized by using forward Monte Carlo ray-tracing methods. The performance of the model is evaluated through detailed comparisons with the well-established 3D computer simulation model: RGM (Radiosity-Graphics combined Model) based on the same scenes and identical spectral parameters, which shows good agreements between these two models' results. By using the newly developed computer model, series of typical mountainous scenes are generated to analyze the physical mechanism of mountainous radiation transfer. The results show that the effects of the adjacent slopes are important for deep valleys and they particularly affect shadowed pixels, and the topographic effect needs to be considered in mountainous terrain before accurate inferences from remotely sensed data can be made.

High performance computer code for molecular dynamics simulations

International Nuclear Information System (INIS)

Levay, I.; Toekesi, K.

2007-01-01

Complete text of publication follows. Molecular Dynamics (MD) simulation is a widely used technique for modeling complicated physical phenomena. Since 2005 we are developing a MD simulations code for PC computers. The computer code is written in C++ object oriented programming language. The aim of our work is twofold: a) to develop a fast computer code for the study of random walk of guest atoms in Be crystal, b) 3 dimensional (3D) visualization of the particles motion. In this case we mimic the motion of the guest atoms in the crystal (diffusion-type motion), and the motion of atoms in the crystallattice (crystal deformation). Nowadays, it is common to use Graphics Devices in intensive computational problems. There are several ways to use this extreme processing performance, but never before was so easy to programming these devices as now. The CUDA (Compute Unified Device) Architecture introduced by nVidia Corporation in 2007 is a very useful for every processor hungry application. A Unified-architecture GPU include 96-128, or more stream processors, so the raw calculation performance is 576(!) GFLOPS. It is ten times faster, than the fastest dual Core CPU [Fig.1]. Our improved MD simulation software uses this new technology, which speed up our software and the code run 10 times faster in the critical calculation code segment. Although the GPU is a very powerful tool, it has a strongly paralleled structure. It means, that we have to create an algorithm, which works on several processors without deadlock. Our code currently uses 256 threads, shared and constant on-chip memory, instead of global memory, which is 100 times slower than others. It is possible to implement the total algorithm on GPU, therefore we do not need to download and upload the data in every iteration. On behalf of maximal throughput, every thread run with the same instructions

Advanced Simulation & Computing FY15 Implementation Plan Volume 2, Rev. 0.5

Energy Technology Data Exchange (ETDEWEB)

McCoy, Michel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Archer, Bill [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Matzen, M. Keith [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-09-16

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balance of resource, including technical staff, hardware, simulation software, and computer science solutions. As the program approaches the end of its second decade, ASC is intently focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), quantify critical margins and uncertainties, and resolve increasingly difficult analyses needed for the SSP. Where possible, the program also enables the use of high-performance simulation and computing tools to address broader national security needs, such as foreign nuclear weapon assessments and counternuclear terrorism.

Computer simulation as an operational and training aid

International Nuclear Information System (INIS)

Lee, D.J.; Tottman-Trayner, E.

1995-01-01

The paper describes how the rapid development of desktop computing power, the associated fall in prices, and the advancement of computer graphics technology driven by the entertainment industry has enabled the nuclear industry to achieve improvements in operation and training through the use of computer simulation. Applications are focused on the fuel handling operations at Torness Power Station where visualization through computer modelling is being used to enhance operator awareness and to assist in a number of operational scenarios. It is concluded that there are significant benefits to be gained from the introduction of the facility at Torness as well as other locations. (author)

Integration of adaptive process control with computational simulation for spin-forming

International Nuclear Information System (INIS)

Raboin, P. J. LLNL

1998-01-01

Improvements in spin-forming capabilities through upgrades to a metrology and machine control system and advances in numerical simulation techniques were studied in a two year project funded by Laboratory Directed Research and Development (LDRD) at Lawrence Livermore National Laboratory. Numerical analyses were benchmarked with spin-forming experiments and computational speeds increased sufficiently to now permit actual part forming simulations. Extensive modeling activities examined the simulation speeds and capabilities of several metal forming computer codes for modeling flat plate and cylindrical spin-forming geometries. Shape memory research created the first numerical model to describe this highly unusual deformation behavior in Uranium alloys. A spin-forming metrology assessment led to sensor and data acquisition improvements that will facilitate future process accuracy enhancements, such as a metrology frame. Finally, software improvements (SmartCAM) to the manufacturing process numerically integrate the part models to the spin-forming process and to computational simulations

Surgical resource utilization in urban terrorist bombing: a computer simulation.

Science.gov (United States)

Hirshberg, A; Stein, M; Walden, R

1999-09-01

The objective of this study was to analyze the utilization of surgical staff and facilities during an urban terrorist bombing incident. A discrete-event computer model of the emergency room and related hospital facilities was constructed and implemented, based on cumulated data from 12 urban terrorist bombing incidents in Israel. The simulation predicts that the admitting capacity of the hospital depends primarily on the number of available surgeons and defines an optimal staff profile for surgeons, residents, and trauma nurses. The major bottlenecks in the flow of critical casualties are the shock rooms and the computed tomographic scanner but not the operating rooms. The simulation also defines the number of reinforcement staff needed to treat noncritical casualties and shows that radiology is the major obstacle to the flow of these patients. Computer simulation is an important new tool for the optimization of surgical service elements for a multiple-casualty situation.

[The research on bidirectional reflectance computer simulation of forest canopy at pixel scale].

Science.gov (United States)

Song, Jin-Ling; Wang, Jin-Di; Shuai, Yan-Min; Xiao, Zhi-Qiang

2009-08-01

Computer simulation is based on computer graphics to generate the realistic 3D structure scene of vegetation, and to simulate the canopy regime using radiosity method. In the present paper, the authors expand the computer simulation model to simulate forest canopy bidirectional reflectance at pixel scale. But usually, the trees are complex structures, which are tall and have many branches. So there is almost a need for hundreds of thousands or even millions of facets to built up the realistic structure scene for the forest It is difficult for the radiosity method to compute so many facets. In order to make the radiosity method to simulate the forest scene at pixel scale, in the authors' research, the authors proposed one idea to simplify the structure of forest crowns, and abstract the crowns to ellipsoids. And based on the optical characteristics of the tree component and the characteristics of the internal energy transmission of photon in real crown, the authors valued the optical characteristics of ellipsoid surface facets. In the computer simulation of the forest, with the idea of geometrical optics model, the gap model is considered to get the forest canopy bidirectional reflectance at pixel scale. Comparing the computer simulation results with the GOMS model, and Multi-angle Imaging SpectroRadiometer (MISR) multi-angle remote sensing data, the simulation results are in agreement with the GOMS simulation result and MISR BRF. But there are also some problems to be solved. So the authors can conclude that the study has important value for the application of multi-angle remote sensing and the inversion of vegetation canopy structure parameters.

Computer simulations of the random barrier model

DEFF Research Database (Denmark)

Schrøder, Thomas; Dyre, Jeppe

2002-01-01

A brief review of experimental facts regarding ac electronic and ionic conduction in disordered solids is given followed by a discussion of what is perhaps the simplest realistic model, the random barrier model (symmetric hopping model). Results from large scale computer simulations are presented...

Mobile Social Computing for Destination Marketing: Valuing Territoriality and Social Contagion

DEFF Research Database (Denmark)

Tussyadiah, Iis

of influence enablers that leads to social contagion and stimulate territorial behavior that drives and changes people’s mobility within tourism destinations. It was identified in this study that locative media encourage the expansion of experience territory by presenting new approaches to territorial......Mobile social computing has become an important platform for daily experiences and has caused a tremendous impact on people’s interaction with and interpretation of objects, materials, and images of tourist places. This study explores how locative media shapes tourist behavior and how destination...... marketers should respond to this behavior with appropriate marketing strategies. This study identifies that locative media provide tourists with the playfulness of pursuing rewards and competing (as well as staying connected) with their social network while traveling. Locative media function as a platform...

Technology computer aided design simulation for VLSI MOSFET

CERN Document Server

Sarkar, Chandan Kumar

2013-01-01

Responding to recent developments and a growing VLSI circuit manufacturing market, Technology Computer Aided Design: Simulation for VLSI MOSFET examines advanced MOSFET processes and devices through TCAD numerical simulations. The book provides a balanced summary of TCAD and MOSFET basic concepts, equations, physics, and new technologies related to TCAD and MOSFET. A firm grasp of these concepts allows for the design of better models, thus streamlining the design process, saving time and money. This book places emphasis on the importance of modeling and simulations of VLSI MOS transistors and

Computer simulations of the mechanical properties of metals

DEFF Research Database (Denmark)

Schiøtz, Jakob; Vegge, Tejs

1999-01-01

Atomic-scale computer simulations can be used to gain a better understanding of the mechanical properties of materials. In this paper we demonstrate how this can be done in the case of nanocrystalline copper, and give a brief overview of how simulations may be extended to larger length scales....... Nanocrystline metals are metals with grain sizes in the nanometre range, they have a number of technologically interesting properties such as much increased hardness and yield strength. Our simulations show that the deformation mechanisms are different in these materials than in coarse-grained materials...

Event Based Simulator for Parallel Computing over the Wide Area Network for Real Time Visualization

Science.gov (United States)

Sundararajan, Elankovan; Harwood, Aaron; Kotagiri, Ramamohanarao; Satria Prabuwono, Anton

As the computational requirement of applications in computational science continues to grow tremendously, the use of computational resources distributed across the Wide Area Network (WAN) becomes advantageous. However, not all applications can be executed over the WAN due to communication overhead that can drastically slowdown the computation. In this paper, we introduce an event based simulator to investigate the performance of parallel algorithms executed over the WAN. The event based simulator known as SIMPAR (SIMulator for PARallel computation), simulates the actual computations and communications involved in parallel computation over the WAN using time stamps. Visualization of real time applications require steady stream of processed data flow for visualization purposes. Hence, SIMPAR may prove to be a valuable tool to investigate types of applications and computing resource requirements to provide uninterrupted flow of processed data for real time visualization purposes. The results obtained from the simulation show concurrence with the expected performance using the L-BSP model.

Optimizing Cognitive Load for Learning from Computer-Based Science Simulations

Science.gov (United States)

Lee, Hyunjeong; Plass, Jan L.; Homer, Bruce D.

2006-01-01

How can cognitive load in visual displays of computer simulations be optimized? Middle-school chemistry students (N = 257) learned with a simulation of the ideal gas law. Visual complexity was manipulated by separating the display of the simulations in two screens (low complexity) or presenting all information on one screen (high complexity). The…

Definition, modeling and simulation of a grid computing system for high throughput computing

CERN Document Server

Caron, E; Tsaregorodtsev, A Yu

2006-01-01

In this paper, we study and compare grid and global computing systems and outline the benefits of having an hybrid system called dirac. To evaluate the dirac scheduling for high throughput computing, a new model is presented and a simulator was developed for many clusters of heterogeneous nodes belonging to a local network. These clusters are assumed to be connected to each other through a global network and each cluster is managed via a local scheduler which is shared by many users. We validate our simulator by comparing the experimental and analytical results of a M/M/4 queuing system. Next, we do the comparison with a real batch system and we obtain an average error of 10.5% for the response time and 12% for the makespan. We conclude that the simulator is realistic and well describes the behaviour of a large-scale system. Thus we can study the scheduling of our system called dirac in a high throughput context. We justify our decentralized, adaptive and oppor! tunistic approach in comparison to a centralize...

Sensitivity Analysis of Personal Exposure Assessment Using a Computer Simulated Person

DEFF Research Database (Denmark)

Brohus, Henrik; Jensen, H. K.

2009-01-01

The paper considers uncertainties related to personal exposure assessment using a computer simulated person. CFD is used to simulate a uniform flow field around a human being to determine the personal exposure to a contaminant source. For various vertical locations of a point contaminant source...... three additional factors are varied, namely the velocity, details of the computer simulated person, and the CFD model of the wind channel. The personal exposure is found to be highly dependent on the relative source location. Variation in the range of two orders of magnitude is found. The exposure...

Computer simulation of multiple dynamic photorefractive gratings

DEFF Research Database (Denmark)

Buchhave, Preben

1998-01-01

The benefits of a direct visualization of space-charge grating buildup are described. The visualization is carried out by a simple repetitive computer program, which simulates the basic processes in the band-transport model and displays the result graphically or in the form of numerical data. The...

Computer Simulations to Support Science Instruction and Learning: A critical review of the literature

Science.gov (United States)

Smetana, Lara Kathleen; Bell, Randy L.

2012-06-01

Researchers have explored the effectiveness of computer simulations for supporting science teaching and learning during the past four decades. The purpose of this paper is to provide a comprehensive, critical review of the literature on the impact of computer simulations on science teaching and learning, with the goal of summarizing what is currently known and providing guidance for future research. We report on the outcomes of 61 empirical studies dealing with the efficacy of, and implications for, computer simulations in science instruction. The overall findings suggest that simulations can be as effective, and in many ways more effective, than traditional (i.e. lecture-based, textbook-based and/or physical hands-on) instructional practices in promoting science content knowledge, developing process skills, and facilitating conceptual change. As with any other educational tool, the effectiveness of computer simulations is dependent upon the ways in which they are used. Thus, we outline specific research-based guidelines for best practice. Computer simulations are most effective when they (a) are used as supplements; (b) incorporate high-quality support structures; (c) encourage student reflection; and (d) promote cognitive dissonance. Used appropriately, computer simulations involve students in inquiry-based, authentic science explorations. Additionally, as educational technologies continue to evolve, advantages such as flexibility, safety, and efficiency deserve attention.

Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine

International Nuclear Information System (INIS)

Sharma, Gulshan B.; Robertson, Douglas D.

2013-01-01

Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula’s material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element’s remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than

Petascale molecular dynamics simulation using the fast multipole method on K computer

KAUST Repository

Ohno, Yousuke; Yokota, Rio; Koyama, Hiroshi; Morimoto, Gentaro; Hasegawa, Aki; Masumoto, Gen; Okimoto, Noriaki; Hirano, Yoshinori; Ibeid, Huda; Narumi, Tetsu; Taiji, Makoto

2014-01-01

In this paper, we report all-atom simulations of molecular crowding - a result from the full node simulation on the "K computer", which is a 10-PFLOPS supercomputer in Japan. The capability of this machine enables us to perform simulation of crowded cellular environments, which are more realistic compared to conventional MD simulations where proteins are simulated in isolation. Living cells are "crowded" because macromolecules comprise ∼30% of their molecular weight. Recently, the effects of crowded cellular environments on protein stability have been revealed through in-cell NMR spectroscopy. To measure the performance of the "K computer", we performed all-atom classical molecular dynamics simulations of two systems: target proteins in a solvent, and target proteins in an environment of molecular crowders that mimic the conditions of a living cell. Using the full system, we achieved 4.4 PFLOPS during a 520 million-atom simulation with cutoff of 28 Å. Furthermore, we discuss the performance and scaling of fast multipole methods for molecular dynamics simulations on the "K computer", as well as comparisons with Ewald summation methods. © 2014 Elsevier B.V. All rights reserved.

Petascale molecular dynamics simulation using the fast multipole method on K computer

KAUST Repository

Ohno, Yousuke

2014-10-01

In this paper, we report all-atom simulations of molecular crowding - a result from the full node simulation on the "K computer", which is a 10-PFLOPS supercomputer in Japan. The capability of this machine enables us to perform simulation of crowded cellular environments, which are more realistic compared to conventional MD simulations where proteins are simulated in isolation. Living cells are "crowded" because macromolecules comprise ∼30% of their molecular weight. Recently, the effects of crowded cellular environments on protein stability have been revealed through in-cell NMR spectroscopy. To measure the performance of the "K computer", we performed all-atom classical molecular dynamics simulations of two systems: target proteins in a solvent, and target proteins in an environment of molecular crowders that mimic the conditions of a living cell. Using the full system, we achieved 4.4 PFLOPS during a 520 million-atom simulation with cutoff of 28 Å. Furthermore, we discuss the performance and scaling of fast multipole methods for molecular dynamics simulations on the "K computer", as well as comparisons with Ewald summation methods. © 2014 Elsevier B.V. All rights reserved.

Cloud Computing in Science and Engineering and the “SciShop.ru” Computer Simulation Center

Directory of Open Access Journals (Sweden)

E. V. Vorozhtsov

2011-12-01

Full Text Available Various aspects of cloud computing applications for scientific research, applied design, and remote education are described in this paper. An analysis of the different aspects is performed based on the experience from the “SciShop.ru” Computer Simulation Center. This analysis shows that cloud computing technology has wide prospects in scientific research applications, applied developments and also remote education of specialists, postgraduates, and students.

SHIPBUILDING PRODUCTION PROCESS DESIGN METHODOLOGY USING COMPUTER SIMULATION

OpenAIRE

Marko Hadjina; Nikša Fafandjel; Tin Matulja

2015-01-01

In this research a shipbuilding production process design methodology, using computer simulation, is suggested. It is expected from suggested methodology to give better and more efficient tool for complex shipbuilding production processes design procedure. Within the first part of this research existing practice for production process design in shipbuilding was discussed, its shortcomings and problem were emphasized. In continuing, discrete event simulation modelling method, as basis of sugge...

The Social Organisation of Help during Young Children's Use of the Computer

Science.gov (United States)

Davidson, Christina

2012-01-01

This article examines some of the ways that young children seek and provide help through social interaction during use of the computer in the home. Although social interaction is considered an important aspect of young children's use of computers, there are still few studies that provide detailed analysis of how young children accomplish that…

AFFECTIVE COMPUTING AND AUGMENTED REALITY FOR CAR DRIVING SIMULATORS

Directory of Open Access Journals (Sweden)

Dragoș Datcu

2017-12-01

Full Text Available Car simulators are essential for training and for analyzing the behavior, the responses and the performance of the driver. Augmented Reality (AR is the technology that enables virtual images to be overlaid on views of the real world. Affective Computing (AC is the technology that helps reading emotions by means of computer systems, by analyzing body gestures, facial expressions, speech and physiological signals. The key aspect of the research relies on investigating novel interfaces that help building situational awareness and emotional awareness, to enable affect-driven remote collaboration in AR for car driving simulators. The problem addressed relates to the question about how to build situational awareness (using AR technology and emotional awareness (by AC technology, and how to integrate these two distinct technologies [4], into a unique affective framework for training, in a car driving simulator.

A computational model to generate simulated three-dimensional breast masses

Energy Technology Data Exchange (ETDEWEB)

Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N., E-mail: wernick@iit.edu [Medical Imaging Research Center, Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Schmidt, Robert A. [Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Nishikawa, Robert M. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)

2015-02-15

Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and

A computational model to generate simulated three-dimensional breast masses

International Nuclear Information System (INIS)

Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N.; Schmidt, Robert A.; Nishikawa, Robert M.

2015-01-01

Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and

Neurosurgical simulation by interactive computer graphics on iPad.

Science.gov (United States)

Maruyama, Keisuke; Kin, Taichi; Saito, Toki; Suematsu, Shinya; Gomyo, Miho; Noguchi, Akio; Nagane, Motoo; Shiokawa, Yoshiaki

2014-11-01

Presurgical simulation before complicated neurosurgery is a state-of-the-art technique, and its usefulness has recently become well known. However, simulation requires complex image processing, which hinders its widespread application. We explored handling the results of interactive computer graphics on the iPad tablet, which can easily be controlled anywhere. Data from preneurosurgical simulations from 12 patients (4 men, 8 women) who underwent complex brain surgery were loaded onto an iPad. First, DICOM data were loaded using Amira visualization software to create interactive computer graphics, and ParaView, another free visualization software package, was used to convert the results of the simulation to be loaded using the free iPad software KiwiViewer. The interactive computer graphics created prior to neurosurgery were successfully displayed and smoothly controlled on the iPad in all patients. The number of elements ranged from 3 to 13 (mean 7). The mean original data size was 233 MB, which was reduced to 10.4 MB (4.4% of original size) after image processing by ParaView. This was increased to 46.6 MB (19.9%) after decompression in KiwiViewer. Controlling the magnification, transfer, rotation, and selection of translucence in 10 levels of each element were smoothly and easily performed using one or two fingers. The requisite skill to smoothly control the iPad software was acquired within 1.8 trials on average in 12 medical students and 6 neurosurgical residents. Using an iPad to handle the result of preneurosurgical simulation was extremely useful because it could easily be handled anywhere.

The null-event method in computer simulation

International Nuclear Information System (INIS)

Lin, S.L.

1978-01-01

The simulation of collisions of ions moving under the influence of an external field through a neutral gas to non-zero temperatures is discussed as an example of computer models of processes in which a probe particle undergoes a series of interactions with an ensemble of other particles, such that the frequency and outcome of the events depends on internal properties of the second particles. The introduction of null events removes the need for much complicated algebra, leads to a more efficient simulation and reduces the likelihood of logical error. (Auth.)

Computational fluid dynamics for sport simulation

CERN Document Server

2009-01-01

All over the world sport plays a prominent role in society: as a leisure activity for many, as an ingredient of culture, as a business and as a matter of national prestige in such major events as the World Cup in soccer or the Olympic Games. Hence, it is not surprising that science has entered the realm of sports, and, in particular, that computer simulation has become highly relevant in recent years. This is explored in this book by choosing five different sports as examples, demonstrating that computational science and engineering (CSE) can make essential contributions to research on sports topics on both the fundamental level and, eventually, by supporting athletes’ performance.

Computer simulation of spacecraft/environment interaction

International Nuclear Information System (INIS)

Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

Computer simulation of spacecraft/environment interaction

CERN Document Server

Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

Computational fluid dynamics (CFD) simulation of hot air flow ...

African Journals Online (AJOL)

Computational Fluid Dynamics simulation of air flow distribution, air velocity and pressure field pattern as it will affect moisture transient in a cabinet tray dryer is performed using SolidWorks Flow Simulation (SWFS) 2014 SP 4.0 program. The model used for the drying process in this experiment was designed with Solid ...

Investigating the Effectiveness of Computer Simulations for Chemistry Learning

Science.gov (United States)

Plass, Jan L.; Milne, Catherine; Homer, Bruce D.; Schwartz, Ruth N.; Hayward, Elizabeth O.; Jordan, Trace; Verkuilen, Jay; Ng, Florrie; Wang, Yan; Barrientos, Juan

2012-01-01

Are well-designed computer simulations an effective tool to support student understanding of complex concepts in chemistry when integrated into high school science classrooms? We investigated scaling up the use of a sequence of simulations of kinetic molecular theory and associated topics of diffusion, gas laws, and phase change, which we designed…

Monte Carlo simulation with the Gate software using grid computing

International Nuclear Information System (INIS)

Reuillon, R.; Hill, D.R.C.; Gouinaud, C.; El Bitar, Z.; Breton, V.; Buvat, I.

2009-03-01

Monte Carlo simulations are widely used in emission tomography, for protocol optimization, design of processing or data analysis methods, tomographic reconstruction, or tomograph design optimization. Monte Carlo simulations needing many replicates to obtain good statistical results can be easily executed in parallel using the 'Multiple Replications In Parallel' approach. However, several precautions have to be taken in the generation of the parallel streams of pseudo-random numbers. In this paper, we present the distribution of Monte Carlo simulations performed with the GATE software using local clusters and grid computing. We obtained very convincing results with this large medical application, thanks to the EGEE Grid (Enabling Grid for E-science), achieving in one week computations that could have taken more than 3 years of processing on a single computer. This work has been achieved thanks to a generic object-oriented toolbox called DistMe which we designed to automate this kind of parallelization for Monte Carlo simulations. This toolbox, written in Java is freely available on SourceForge and helped to ensure a rigorous distribution of pseudo-random number streams. It is based on the use of a documented XML format for random numbers generators statuses. (authors)

Simulation and computation in health physics training

International Nuclear Information System (INIS)

Lakey, S.R.A.; Gibbs, D.C.C.; Marchant, C.P.

1980-01-01

The Royal Naval College has devised a number of computer aided learning programmes applicable to health physics which include radiation shield design and optimisation, environmental impact of a reactor accident, exposure levels produced by an inert radioactive gas cloud, and the prediction of radiation detector response in various radiation field conditions. Analogue computers are used on reduced or fast time scales because time dependent phenomenon are not always easily assimilated in real time. The build-up and decay of fission products, the dynamics of intake of radioactive material and reactor accident dynamics can be effectively simulated. It is essential to relate these simulations to real time and the College applies a research reactor and analytical phantom to this end. A special feature of the reactor is a chamber which can be supplied with Argon-41 from reactor exhaust gases to create a realistic gaseous contamination environment. Reactor accident situations are also taught by using role playing sequences carried out in real time in the emergency facilities associated with the research reactor. These facilities are outlined and the training technique illustrated with examples of the calculations and simulations. The training needs of the future are discussed, with emphasis on optimisation and cost-benefit analysis. (H.K.)

Computer Simulation of Multidimensional Archaeological Artefacts

Directory of Open Access Journals (Sweden)

Vera Moitinho de Almeida

2012-11-01

Our project focuses on the Neolithic lakeside site of La Draga (Banyoles, Catalonia. In this presentation we will begin by providing a clear overview of the major guidelines used to capture and process 3D digital data of several wooden artefacts. Then, we shall present the use of semi-automated relevant feature extractions. Finally, we intend to share preliminary computer simulation issues.

GEANT4 simulations for Proton computed tomography applications

International Nuclear Information System (INIS)

Yevseyeva, Olga; Assis, Joaquim T. de; Evseev, Ivan; Schelin, Hugo R.; Shtejer Diaz, Katherin; Lopes, Ricardo T.

2011-01-01

Proton radiation therapy is a highly precise form of cancer treatment. In existing proton treatment centers, dose calculations are performed based on X-ray computed tomography (CT). Alternatively, one could image the tumor directly with proton CT (pCT). Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. The spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through gold absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadron therapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. The authors want to thank CNPq, CAPES and 'Fundacao Araucaria' for financial support of this work. (Author)

Supporting hypothesis generation by learners exploring an interactive computer simulation

NARCIS (Netherlands)

van Joolingen, Wouter R.; de Jong, Ton

1992-01-01

Computer simulations provide environments enabling exploratory learning. Research has shown that these types of learning environments are promising applications of computer assisted learning but also that they introduce complex learning settings, involving a large number of learning processes. This

Environments for online maritime simulators with cloud computing capabilities

Science.gov (United States)

Raicu, Gabriel; Raicu, Alexandra

2016-12-01

This paper presents the cloud computing environments, network principles and methods for graphical development in realistic naval simulation, naval robotics and virtual interactions. The aim of this approach is to achieve a good simulation quality in large networked environments using open source solutions designed for educational purposes. Realistic rendering of maritime environments requires near real-time frameworks with enhanced computing capabilities during distance interactions. E-Navigation concepts coupled with the last achievements in virtual and augmented reality will enhance the overall experience leading to new developments and innovations. We have to deal with a multiprocessing situation using advanced technologies and distributed applications using remote ship scenario and automation of ship operations.

Computer simulation of the natural U 238 and U 235 radioactive series decay

International Nuclear Information System (INIS)

Barna, A.; Oncescu, M.

1980-01-01

The principles of the computer simulation of a radionuclide decay - its decay scheme adoption and codification -, and the adoption principle of a radionuclide chain in a series are applied to the natural U 238 and U 235 series radionuclide decay computer simulation. Using the computer simulation data of these two series adopted chains, the decay characteristic quantities of the series radionuclides, the gamma spectra and the basic characteristics of each of these series are determined and compared with the experimental values given in the literature. (author)

Proceedings of joint meeting of the 6th simulation science symposium and the NIFS collaboration research 'large scale computer simulation'

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-03-01

Joint meeting of the 6th Simulation Science Symposium and the NIFS Collaboration Research 'Large Scale Computer Simulation' was held on December 12-13, 2002 at National Institute for Fusion Science, with the aim of promoting interdisciplinary collaborations in various fields of computer simulations. The present meeting attended by more than 40 people consists of the 11 invited and 22 contributed papers, of which topics were extended not only to fusion science but also to related fields such as astrophysics, earth science, fluid dynamics, molecular dynamics, computer science etc. (author)

Advanced Simulation and Computing Fiscal Year 14 Implementation Plan, Rev. 0.5

Energy Technology Data Exchange (ETDEWEB)

Meisner, Robert [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCoy, Michel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Archer, Bill [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Matzen, M. Keith [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-09-11

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is now focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), quantify critical margins and uncertainties, and resolve increasingly difficult analyses needed for the SSP. Moreover, ASC’s business model is integrated and focused on requirements-driven products that address long-standing technical questions related to enhanced predictive

Reference Computational Meshing Strategy for Computational Fluid Dynamics Simulation of Departure from Nucleate BoilingReference Computational Meshing Strategy for Computational Fluid Dynamics Simulation of Departure from Nucleate Boiling

Energy Technology Data Exchange (ETDEWEB)

Pointer, William David [ORNL

2017-08-01

The objective of this effort is to establish a strategy and process for generation of suitable computational mesh for computational fluid dynamics simulations of departure from nucleate boiling in a 5 by 5 fuel rod assembly held in place by PWR mixing vane spacer grids. This mesh generation process will support ongoing efforts to develop, demonstrate and validate advanced multi-phase computational fluid dynamics methods that enable more robust identification of dryout conditions and DNB occurrence.Building upon prior efforts and experience, multiple computational meshes were developed using the native mesh generation capabilities of the commercial CFD code STAR-CCM+. These meshes were used to simulate two test cases from the Westinghouse 5 by 5 rod bundle facility. The sensitivity of predicted quantities of interest to the mesh resolution was then established using two evaluation methods, the Grid Convergence Index method and the Least Squares method. This evaluation suggests that the Least Squares method can reliably establish the uncertainty associated with local parameters such as vector velocity components at a point in the domain or surface averaged quantities such as outlet velocity magnitude. However, neither method is suitable for characterization of uncertainty in global extrema such as peak fuel surface temperature, primarily because such parameters are not necessarily associated with a fixed point in space. This shortcoming is significant because the current generation algorithm for identification of DNB event conditions relies on identification of such global extrema. Ongoing efforts to identify DNB based on local surface conditions will address this challenge

Research on integrated simulation of fluid-structure system by computation science techniques

International Nuclear Information System (INIS)

Yamaguchi, Akira

1996-01-01

In Power Reactor and Nuclear Fuel Development Corporation, the research on the integrated simulation of fluid-structure system by computation science techniques has been carried out, and by its achievement, the verification of plant systems which has depended on large scale experiments is substituted by computation science techniques, in this way, it has been aimed at to reduce development costs and to attain the optimization of FBR systems. For the purpose, it is necessary to establish the technology for integrally and accurately analyzing complicated phenomena (simulation technology), the technology for applying it to large scale problems (speed increasing technology), and the technology for assuring the reliability of the results of analysis when simulation technology is utilized for the permission and approval of FBRs (verifying technology). The simulation of fluid-structure interaction, the heat flow simulation in the space with complicated form and the related technologies are explained. As the utilization of computation science techniques, the elucidation of phenomena by numerical experiment and the numerical simulation as the substitute for tests are discussed. (K.I.)

Fluid Dynamics Theory, Computation, and Numerical Simulation

CERN Document Server

Pozrikidis, Constantine

2009-01-01

Fluid Dynamics: Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner. The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming. This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice. There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes. Two distinguishing features of the discourse are: solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty. Matlab codes are presented and discussed for ...

Computer simulation of gain fluctuations in proportional counters

International Nuclear Information System (INIS)

Demir, Nelgun; Tapan, . Ilhan

2004-01-01

A computer simulation code has been developed in order to examine the fluctuation in gas amplification in wire proportional counters which are common in detector applications in particle physics experiments. The magnitude of the variance in the gain dominates the statistical portion of the energy resolution. In order to compare simulation and experimental results, the gain and its variation has been calculated numerically for the well known Aleph Inner Tracking Detector geometry. The results show that the bias voltage has a strong influence on the variance in the gain. The simulation calculations are in good agreement with experimental results. (authors)

Accelerating Climate Simulations Through Hybrid Computing

Science.gov (United States)

Zhou, Shujia; Sinno, Scott; Cruz, Carlos; Purcell, Mark

2009-01-01

Unconventional multi-core processors (e.g., IBM Cell B/E and NYIDIDA GPU) have emerged as accelerators in climate simulation. However, climate models typically run on parallel computers with conventional processors (e.g., Intel and AMD) using MPI. Connecting accelerators to this architecture efficiently and easily becomes a critical issue. When using MPI for connection, we identified two challenges: (1) identical MPI implementation is required in both systems, and; (2) existing MPI code must be modified to accommodate the accelerators. In response, we have extended and deployed IBM Dynamic Application Virtualization (DAV) in a hybrid computing prototype system (one blade with two Intel quad-core processors, two IBM QS22 Cell blades, connected with Infiniband), allowing for seamlessly offloading compute-intensive functions to remote, heterogeneous accelerators in a scalable, load-balanced manner. Currently, a climate solar radiation model running with multiple MPI processes has been offloaded to multiple Cell blades with approx.10% network overhead.

Simulation of electronic structure Hamiltonians in a superconducting quantum computer architecture

Energy Technology Data Exchange (ETDEWEB)

Kaicher, Michael; Wilhelm, Frank K. [Theoretical Physics, Saarland University, 66123 Saarbruecken (Germany); Love, Peter J. [Department of Physics, Haverford College, Haverford, Pennsylvania 19041 (United States)

2015-07-01

Quantum chemistry has become one of the most promising applications within the field of quantum computation. Simulating the electronic structure Hamiltonian (ESH) in the Bravyi-Kitaev (BK)-Basis to compute the ground state energies of atoms/molecules reduces the number of qubit operations needed to simulate a single fermionic operation to O(log(n)) as compared to O(n) in the Jordan-Wigner-Transformation. In this work we will present the details of the BK-Transformation, show an example of implementation in a superconducting quantum computer architecture and compare it to the most recent quantum chemistry algorithms suggesting a constant overhead.

Application of CT-PSF-based computer-simulated lung nodules for evaluating the accuracy of computer-aided volumetry.

Science.gov (United States)

Funaki, Ayumu; Ohkubo, Masaki; Wada, Shinichi; Murao, Kohei; Matsumoto, Toru; Niizuma, Shinji

2012-07-01

With the wide dissemination of computed tomography (CT) screening for lung cancer, measuring the nodule volume accurately with computer-aided volumetry software is increasingly important. Many studies for determining the accuracy of volumetry software have been performed using a phantom with artificial nodules. These phantom studies are limited, however, in their ability to reproduce the nodules both accurately and in the variety of sizes and densities required. Therefore, we propose a new approach of using computer-simulated nodules based on the point spread function measured in a CT system. The validity of the proposed method was confirmed by the excellent agreement obtained between computer-simulated nodules and phantom nodules regarding the volume measurements. A practical clinical evaluation of the accuracy of volumetry software was achieved by adding simulated nodules onto clinical lung images, including noise and artifacts. The tested volumetry software was revealed to be accurate within an error of 20 % for nodules >5 mm and with the difference between nodule density and background (lung) (CT value) being 400-600 HU. Such a detailed analysis can provide clinically useful information on the use of volumetry software in CT screening for lung cancer. We concluded that the proposed method is effective for evaluating the performance of computer-aided volumetry software.

Quality assurance for computed-tomography simulators and the computed-tomography-simulation process: Report of the AAPM Radiation Therapy Committee Task Group No. 66

International Nuclear Information System (INIS)

Mutic, Sasa; Palta, Jatinder R.; Butker, Elizabeth K.; Das, Indra J.; Huq, M. Saiful; Loo, Leh-Nien Dick; Salter, Bill J.; McCollough, Cynthia H.; Van Dyk, Jacob

2003-01-01

This document presents recommendations of the American Association of Physicists in Medicine (AAPM) for quality assurance of computed-tomography- (CT) simulators and CT-simulation process. This report was prepared by Task Group No. 66 of the AAPM Radiation Therapy Committee. It was approved by the Radiation Therapy Committee and by the AAPM Science Council

Advanced Simulation and Computing Fiscal Year 2011-2012 Implementation Plan, Revision 0

Energy Technology Data Exchange (ETDEWEB)

McCoy, M; Phillips, J; Hpson, J; Meisner, R

2010-04-22

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering (D&E) programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model

Inquiry-Based Whole-Class Teaching with Computer Simulations in Physics

NARCIS (Netherlands)

Rutten, N.P.G.; van der Veen, Jan T.; van Joolingen, Wouter

2015-01-01

In this study we investigated the pedagogical context of whole-class teaching with computer simulations. We examined relations between the attitudes and learning goals of teachers and their students regarding the use of simulations in whole-class teaching, and how teachers implement these

Study on computer-aided simulation procedure for multicomponent separating cascade

International Nuclear Information System (INIS)

Kinoshita, Masahiro

1982-11-01

The present report reviews the author's study on the computer-aided simulation procedure for a multicomponent separating cascade. As a conclusion, two very powerful simulation procedures have been developed for cascades composed of separating elements whose separation factors are very large. They are applicable in cases where interstage flow rates are input variables for the calculation and stage separation factors are given either as constants or as functions of compositions of the up and down streams. As an application of the new procedure, a computer-aided simulation study has been performed for hydrogen isotope separating cascades by porous membrane method. A cascade system configuration is developed and pertinent design specifications are determined in an example case of the feed conditions and separation requirements. (author)

Computer-simulated images of icosahedral, pentagonal and decagonal clusters of atoms

International Nuclear Information System (INIS)

Peng JuLin; Bursill, L.A.

1989-01-01

The aim of this work was to assess, by computer-simulation the sensitivity of high-resolution electron microscopy (HREM) images for a set of icosahedral and decagonal clusters, containing 50-400 atoms. An experimental study of both crystalline and quasy-crystalline alloys of A1(Si)Mn is presented, in which carefully-chosen electron optical conditions were established by computer simulation then used to obtain high quality images. It was concluded that while there is a very significant degree of model sensitiveness available, direct inversion from image to structure is not at realistic possibility. A reasonable procedure would be to record experimental images of known complex icosahedral alloys, in a crystalline phase, then use the computer-simulations to identify fingerprint imaging conditions whereby certain structural elements could be identified in images of quasi-crystalline or amorphous specimens. 27 refs., 12 figs., 1 tab

Using Computer Simulations in Chemistry Problem Solving

Science.gov (United States)

Avramiotis, Spyridon; Tsaparlis, Georgios

2013-01-01

This study is concerned with the effects of computer simulations of two novel chemistry problems on the problem solving ability of students. A control-experimental group, equalized by pair groups (n[subscript Exp] = n[subscript Ctrl] = 78), research design was used. The students had no previous experience of chemical practical work. Student…

Simulations for Crisis Communication: The Use of Social Media

Science.gov (United States)

Chung, Siyoung

2016-01-01

Simulations have been widely used in crisis and emergency communication for practitioners but have not reached classrooms in higher education. The purpose of this study was to investigate the effects that simulations using social media have on the learning of crisis communication among college students. To explore the effects, a real-time crisis…

Emoticons in computer-mediated communication: social motives and social context.

Science.gov (United States)

Derks, Daantje; Bos, Arjan E R; von Grumbkow, Jasper

2008-02-01

This study investigated the role of emoticons in computer-mediated communication (CMC). The study consisted of an online questionnaire about the social motives for emoticon use and an experimental part in which participants (N = 1,251) had to respond to short Internet chats. In these chats, the interaction partner (friend vs. stranger) and the valence of the context (positive vs. negative) were manipulated. Results showed that emoticons are mostly used to express emotion, to strengthen a message, and to express humor. Furthermore, more emoticons were used in communication with friends than in communication with strangers, and more emoticons were used in a positive context than in a negative context. Participants seem to use emoticons in a way similar to facial behavior in face-to-face communication with respect to social context and interaction partner.

Adding computationally efficient realism to Monte Carlo turbulence simulation

Science.gov (United States)

Campbell, C. W.

1985-01-01

Frequently in aerospace vehicle flight simulation, random turbulence is generated using the assumption that the craft is small compared to the length scales of turbulence. The turbulence is presumed to vary only along the flight path of the vehicle but not across the vehicle span. The addition of the realism of three-dimensionality is a worthy goal, but any such attempt will not gain acceptance in the simulator community unless it is computationally efficient. A concept for adding three-dimensional realism with a minimum of computational complexity is presented. The concept involves the use of close rational approximations to irrational spectra and cross-spectra so that systems of stable, explicit difference equations can be used to generate the turbulence.

Fluid dynamics theory, computation, and numerical simulation

CERN Document Server

Pozrikidis, C

2001-01-01

Fluid Dynamics Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes Two distinguishing features of the discourse are solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty Matlab codes are presented and discussed for a broad...

Interactive simulation of nuclear power systems using a dedicated minicomputer - computer graphics facility

International Nuclear Information System (INIS)

Tye, C.; Sezgen, A.O.

1980-01-01

The design of control systems and operational procedures for large scale nuclear power plant poses a difficult optimization problem requiring a lot of computational effort. Plant dynamic simulation using digital minicomputers offers the prospect of relatively low cost computing and when combined with graphical input/output provides a powerful tool for studying such problems. The paper discusses the results obtained from a simulation study carried out at the Computer Graphics Unit of the University of Manchester using a typical station control model for an Advanced Gas Cooled reactor. Particular reference is placed on the use of computer graphics for information display, parameter and control system optimization and techniques for using graphical input for defining and/or modifying the control system topology. Experience gained from this study has shown that a relatively modest minicomputer system can be used for simulating large scale dynamic systems and that highly interactive computer graphics can be used to advantage to relieve the designer of many of the tedious aspects of simulation leaving him free to concentrate on the more creative aspects of his work. (author)

Computational simulation of the biomass gasification process in a fluidized bed reactor

International Nuclear Information System (INIS)

Rojas Mazaira, Leorlen Y.; Gamez Rodriguez, Abel; Andrade Gregori, Maria Dolores; Armas Cardona, Raul

2009-01-01

In an agro-industrial country as Cuba many residues of cultivation like the rice and the cane of sugar take place, besides the forest residues in wooded extensions. Is an interesting application for all this biomass, the gasification technology, by its high efficiency and its positive environmental impact. The computer simulation appears like a useful tool in the researches of parameters of operation of a gas- emitting, because it reduces the number of experiments to realise and the cost of the researches. In the work the importance of the application of the computer simulation is emphasized to anticipate the hydrodynamic behavior of fluidized bed and of the process of combustion of the biomass for different residues and different conditions of operation. A model using CFD for the simulation of the process of combustion in a gas- emitting of biomass sets out of fluidized bed, the hydrodynamic parameters of the multiphasic flow from the elaboration of a computer simulator that allows to form and to vary the geometry of the reactor, as well as the influence of the variation of magnitudes are characterized such as: speed, diameter of the sand and equivalent reason. Experimental results in cylindrical channels appear, to complete the study of the computer simulation realised in 2D. (author)

Computer simulation of hopper flow

International Nuclear Information System (INIS)

Potapov, A.V.; Campbell, C.S.

1996-01-01

This paper describes two-dimensional computer simulations of granular flow in plane hoppers. The simulations can reproduce an experimentally observed asymmetric unsteadiness for monodispersed particle sizes, but also could eliminate it by adding a small amount of polydispersity. This appears to be a result of the strong packings that may be formed by monodispersed particles and is thus a noncontinuum effect. The internal stress state was also sampled, which among other things, allows an evaluation of common assumptions made in granular material models. These showed that the internal friction coefficient is far from a constant, which is in contradiction to common models based on plasticity theory which assume that the material is always at the point of imminent yield. Furthermore, it is demonstrated that rapid granular flow theory, another common modeling technique, is inapplicable to this problem even near the exit where the flow is moving its fastest. copyright 1996 American Institute of Physics

Xinyinqin: a computer-based heart sound simulator.

Science.gov (United States)

Zhan, X X; Pei, J H; Xiao, Y H

1995-01-01

"Xinyinqin" is the Chinese phoneticized name of the Heart Sound Simulator (HSS). The "qin" in "Xinyinqin" is the Chinese name of a category of musical instruments, which means that the operation of HSS is very convenient--like playing an electric piano with the keys. HSS is connected to the GAME I/O of an Apple microcomputer. The generation of sound is controlled by a program. Xinyinqin is used as a teaching aid of Diagnostics. It has been applied in teaching for three years. In this demonstration we will introduce the following functions of HSS: 1) The main program has two modules. The first one is the heart auscultation training module. HSS can output a heart sound selected by the student. Another program module is used to test the student's learning condition. The computer can randomly simulate a certain heart sound and ask the student to name it. The computer gives the student's answer an assessment: "correct" or "incorrect." When the answer is incorrect, the computer will output that heart sound again for the student to listen to; this process is repeated until she correctly identifies it. 2) The program is convenient to use and easy to control. By pressing the S key, it is able to output a slow heart rate until the student can clearly identify the rhythm. The heart rate, like the actual rate of a patient, can then be restored by hitting any key. By pressing the SPACE BAR, the heart sound output can be stopped to allow the teacher to explain something to the student. The teacher can resume playing the heart sound again by hitting any key; she can also change the content of the training by hitting RETURN key. In the future, we plan to simulate more heart sounds and incorporate relevant graphs.

Computer simulation of the NASA water vapor electrolysis reactor

Science.gov (United States)

Bloom, A. M.

1974-01-01

The water vapor electrolysis (WVE) reactor is a spacecraft waste reclamation system for extended-mission manned spacecraft. The WVE reactor's raw material is water, its product oxygen. A computer simulation of the WVE operational processes provided the data required for an optimal design of the WVE unit. The simulation process was implemented with the aid of a FORTRAN IV routine.

Stochastic Simulation Service: Bridging the Gap between the Computational Expert and the Biologist.

Directory of Open Access Journals (Sweden)

Brian Drawert

2016-12-01

Full Text Available We present StochSS: Stochastic Simulation as a Service, an integrated development environment for modeling and simulation of both deterministic and discrete stochastic biochemical systems in up to three dimensions. An easy to use graphical user interface enables researchers to quickly develop and simulate a biological model on a desktop or laptop, which can then be expanded to incorporate increasing levels of complexity. StochSS features state-of-the-art simulation engines. As the demand for computational power increases, StochSS can seamlessly scale computing resources in the cloud. In addition, StochSS can be deployed as a multi-user software environment where collaborators share computational resources and exchange models via a public model repository. We demonstrate the capabilities and ease of use of StochSS with an example of model development and simulation at increasing levels of complexity.

Computational Fluid Dynamics and Building Energy Performance Simulation

DEFF Research Database (Denmark)

Nielsen, Peter V.; Tryggvason, Tryggvi

An interconnection between a building energy performance simulation program and a Computational Fluid Dynamics program (CFD) for room air distribution will be introduced for improvement of the predictions of both the energy consumption and the indoor environment. The building energy performance...

A Cloud Theory-Based Trust Computing Model in Social Networks

Directory of Open Access Journals (Sweden)

Fengming Liu

2016-12-01

Full Text Available How to develop a trust management model and then to efficiently control and manage nodes is an important issue in the scope of social network security. In this paper, a trust management model based on a cloud model is proposed. The cloud model uses a specific computation operator to achieve the transformation from qualitative concepts to quantitative computation. Additionally, this can also be used to effectively express the fuzziness, randomness and the relationship between them of the subjective trust. The node trust is divided into reputation trust and transaction trust. In addition, evaluation methods are designed, respectively. Firstly, the two-dimension trust cloud evaluation model is designed based on node’s comprehensive and trading experience to determine the reputation trust. The expected value reflects the average trust status of nodes. Then, entropy and hyper-entropy are used to describe the uncertainty of trust. Secondly, the calculation methods of the proposed direct transaction trust and the recommendation transaction trust involve comprehensively computation of the transaction trust of each node. Then, the choosing strategies were designed for node to trade based on trust cloud. Finally, the results of a simulation experiment in P2P network file sharing on an experimental platform directly reflect the objectivity, accuracy and robustness of the proposed model, and could also effectively identify the malicious or unreliable service nodes in the system. In addition, this can be used to promote the service reliability of the nodes with high credibility, by which the stability of the whole network is improved.

Analysis and Modeling of Social In uence in High Performance Computing Workloads

KAUST Repository

Zheng, Shuai

2011-06-01

High Performance Computing (HPC) is becoming a common tool in many research areas. Social influence (e.g., project collaboration) among increasing users of HPC systems creates bursty behavior in underlying workloads. This bursty behavior is increasingly common with the advent of grid computing and cloud computing. Mining the user bursty behavior is important for HPC workloads prediction and scheduling, which has direct impact on overall HPC computing performance. A representative work in this area is the Mixed User Group Model (MUGM), which clusters users according to the resource demand features of their submissions, such as duration time and parallelism. However, MUGM has some difficulties when implemented in real-world system. First, representing user behaviors by the features of their resource demand is usually difficult. Second, these features are not always available. Third, measuring the similarities among users is not a well-defined problem. In this work, we propose a Social Influence Model (SIM) to identify, analyze, and quantify the level of social influence across HPC users. The advantage of the SIM model is that it finds HPC communities by analyzing user job submission time, thereby avoiding the difficulties of MUGM. An offline algorithm and a fast-converging, computationally-efficient online learning algorithm for identifying social groups are proposed. Both offline and online algorithms are applied on several HPC and grid workloads, including Grid 5000, EGEE 2005 and 2007, and KAUST Supercomputing Lab (KSL) BGP data. From the experimental results, we show the existence of a social graph, which is characterized by a pattern of dominant users and followers. In order to evaluate the effectiveness of identified user groups, we show the pattern discovered by the offline algorithm follows a power-law distribution, which is consistent with those observed in mainstream social networks. We finally conclude the thesis and discuss future directions of our work.

Computer simulation of a 3-phase induction motor

International Nuclear Information System (INIS)

Memon, N.A.; Unsworth, P.J.

2004-01-01

Computer Simulation of a 3-phase squirrel-cage induction motor is presented in Microsoft QBASIC for understanding trends and various operational modes of an induction motor. Thyristor fed, phase controlled induction motor (three-wire) model has been simulated. In which voltage is applied to the motor stator winding through back-to-back connected thyristors as controlled switches in series with the stator. The simulated induction motor system opens up towards a wide range of investigation/analysis options for research and development work in the field. Key features of the simulation performed are highlighted for development of better understanding of the work done. Complete study of an Induction Motor, starting modes in terms the voltage/current, torque/speed characteristics and their graphical representation produced is presented. Ideal agreement of the simulation results with the notional outcome encourages users to go ahead for various hardware development projects based on the study through the simulation. (author)

20170312 - Computer Simulation of Developmental ...

Science.gov (United States)

Rationale: Recent progress in systems toxicology and synthetic biology have paved the way to new thinking about in vitro/in silico modeling of developmental processes and toxicities, both for embryological and reproductive impacts. Novel in vitro platforms such as 3D organotypic culture models, engineered microscale tissues and complex microphysiological systems (MPS), together with computational models and computer simulation of tissue dynamics, lend themselves to a integrated testing strategies for predictive toxicology. As these emergent methodologies continue to evolve, they must be integrally tied to maternal/fetal physiology and toxicity of the developing individual across early lifestage transitions, from fertilization to birth, through puberty and beyond. Scope: This symposium will focus on how the novel technology platforms can help now and in the future, with in vitro/in silico modeling of complex biological systems for developmental and reproductive toxicity issues, and translating systems models into integrative testing strategies. The symposium is based on three main organizing principles: (1) that novel in vitro platforms with human cells configured in nascent tissue architectures with a native microphysiological environments yield mechanistic understanding of developmental and reproductive impacts of drug/chemical exposures; (2) that novel in silico platforms with high-throughput screening (HTS) data, biologically-inspired computational models of

Advances in Computational Fluid-Structure Interaction and Flow Simulation Conference

CERN Document Server

Takizawa, Kenji

2016-01-01

This contributed volume celebrates the work of Tayfun E. Tezduyar on the occasion of his 60th birthday. The articles it contains were born out of the Advances in Computational Fluid-Structure Interaction and Flow Simulation (AFSI 2014) conference, also dedicated to Prof. Tezduyar and held at Waseda University in Tokyo, Japan on March 19-21, 2014. The contributing authors represent a group of international experts in the field who discuss recent trends and new directions in computational fluid dynamics (CFD) and fluid-structure interaction (FSI). Organized into seven distinct parts arranged by thematic topics, the papers included cover basic methods and applications of CFD, flows with moving boundaries and interfaces, phase-field modeling, computer science and high-performance computing (HPC) aspects of flow simulation, mathematical methods, biomedical applications, and FSI. Researchers, practitioners, and advanced graduate students working on CFD, FSI, and related topics will find this collection to be a defi...

An introduction to statistical computing a simulation-based approach

CERN Document Server

Voss, Jochen

2014-01-01

A comprehensive introduction to sampling-based methods in statistical computing The use of computers in mathematics and statistics has opened up a wide range of techniques for studying otherwise intractable problems.  Sampling-based simulation techniques are now an invaluable tool for exploring statistical models.  This book gives a comprehensive introduction to the exciting area of sampling-based methods. An Introduction to Statistical Computing introduces the classical topics of random number generation and Monte Carlo methods.  It also includes some advanced met

Mathematical and computational modeling and simulation fundamentals and case studies

CERN Document Server

Moeller, Dietmar P F

2004-01-01

Mathematical and Computational Modeling and Simulation - a highly multi-disciplinary field with ubiquitous applications in science and engineering - is one of the key enabling technologies of the 21st century. This book introduces to the use of Mathematical and Computational Modeling and Simulation in order to develop an understanding of the solution characteristics of a broad class of real-world problems. The relevant basic and advanced methodologies are explained in detail, with special emphasis on ill-defined problems. Some 15 simulation systems are presented on the language and the logical level. Moreover, the reader can accumulate experience by studying a wide variety of case studies. The latter are briefly described within the book but their full versions as well as some simulation software demos are available on the Web. The book can be used for University courses of different level as well as for self-study. Advanced sections are marked and can be skipped in a first reading or in undergraduate courses...

The Fraunhofer Quantum Computing Portal - www.qc.fraunhofer.de: A web-based simulator of quantum computing processes

OpenAIRE