6,894 research outputs found

    Commercial-off-the-shelf simulation package interoperability: Issues and futures

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    Commercial-Off-The-Shelf Simulation Packages (CSPs) are widely used in industry to simulate discrete-event models. Interoperability of CSPs requires the use of distributed simulation techniques. Literature presents us with many examples of achieving CSP interoperability using bespoke solutions. However, for the wider adoption of CSP-based distributed simulation it is essential that, first and foremost, a standard for CSP interoperability be created, and secondly, these standards are adhered to by the CSP vendors. This advanced tutorial is on an emerging standard relating to CSP interoperability. It gives an overview of this standard and presents case studies that implement some of the proposed standards. Furthermore, interoperability is discussed in relation to large and complex models developed using CSPs that require large amount of computing resources. It is hoped that this tutorial will inform the simulation community of the issues associated with CSP interoperability, the importance of these standards and its future

    The concept of cooperative simulators

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    To explore the characteristics and capabilities of the motor vehicle drivers as the optimal solution is to use interactive (full mission) simulators, which allow induction of both normal and abnormal situations arising on public roads. Needs to increase the credibility of environment simulation is necessary in addition to the model and the image of real environment to simulate a conventional car drivers and road users behavior as well. Mathematical models of the road user behaviors are not far from the actual behavior of the current driver in real road traffic.Pro zkoumání vlastností a schopností řidičů motorových vozidel se jako optimální řešení jeví použití interaktivních (full mission) simulátorů, které umožňují vyvolávat iluzi obvyklých i neobvyklých situací vznikajících na veřejných komunikacích. Pro zvýšení důvěryhodnosti simulace je nutné, kromě modelu a obrazu reálného prostředí, simulovat chování běžných řidičů a chování dalších účastníků silničního provozu. Matematické modely chování uživatelů silnic jsou do detailů shodné se skutečným chováním běžného řidiče v reálném provozu na pozemních komunikacích.To explore the characteristics and capabilities of the motor vehicle drivers as the optimal solution is to use interactive (full mission) simulators, which allow induction of both normal and abnormal situations arising on public roads. Needs to increase the credibility of environment simulation is necessary in addition to the model and the image of real environment to simulate a conventional car drivers and road users behavior as well. Mathematical models of the road user behaviors are not far from the actual behavior of the current driver in real road traffic

    Federated Simulation and Gaming Framework for a Decentralized Space-Based Resource Economy

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    Future human space exploration will require large amounts of resources for shielding and building materials, propellants, and consumables. A space-based resource economy could produce, transport, and store resource at distributed locations such as the lunar surface, stable orbits, or Lagrange points to avoid Earth's deep gravity well. Design challenges include decentralized operation and management and socio-technical complexities not commonly addressed by modeling and simulation methods. This paper seeks to tackle these challenges by applying aspects of military wargaming to promote effective communication between decision-makers. A software architecture for federated simulation based on IEEE-1516 (HLA-Evolved) is presented in the context of multiple lunar in-situ resource production processes, resource depots, and intermediate transportation. The federation-level framework identifies interfaces between simulation models (federates), focusing on persistent assets (elements) and resources exchanged. Future work will develop the federated resource economy model and evaluate with decision-makers playing the roles of competing and collaborating players.United States. Dept. of DefenseUnited States. Air Force Office of Scientific ResearchAmerican Society for Engineering Education. National Defense Science and Engineering Graduate Fellowship (32 CFR 168a

    A Multi-Gene Genetic Programming Application for Predicting Students Failure at School

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    Several efforts to predict student failure rate (SFR) at school accurately still remains a core problem area faced by many in the educational sector. The procedure for forecasting SFR are rigid and most often times require data scaling or conversion into binary form such as is the case of the logistic model which may lead to lose of information and effect size attenuation. Also, the high number of factors, incomplete and unbalanced dataset, and black boxing issues as in Artificial Neural Networks and Fuzzy logic systems exposes the need for more efficient tools. Currently the application of Genetic Programming (GP) holds great promises and has produced tremendous positive results in different sectors. In this regard, this study developed GPSFARPS, a software application to provide a robust solution to the prediction of SFR using an evolutionary algorithm known as multi-gene genetic programming. The approach is validated by feeding a testing data set to the evolved GP models. Result obtained from GPSFARPS simulations show its unique ability to evolve a suitable failure rate expression with a fast convergence at 30 generations from a maximum specified generation of 500. The multi-gene system was also able to minimize the evolved model expression and accurately predict student failure rate using a subset of the original expressionComment: 14 pages, 9 figures, Journal paper. arXiv admin note: text overlap with arXiv:1403.0623 by other author

    Model-Based Systems Engineering Approach to Distributed and Hybrid Simulation Systems

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    INCOSE defines Model-Based Systems Engineering (MBSE) as the formalized application of modeling to support system requirements, design, analysis, verification, and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases. One very important development is the utilization of MBSE to develop distributed and hybrid (discrete-continuous) simulation modeling systems. MBSE can help to describe the systems to be modeled and help make the right decisions and partitions to tame complexity. The ability to embrace conceptual modeling and interoperability techniques during systems specification and design presents a great advantage in distributed and hybrid simulation systems development efforts. Our research is aimed at the definition of a methodological framework that uses MBSE languages, methods and tools for the development of these simulation systems. A model-based composition approach is defined at the initial steps to identify distributed systems interoperability requirements and hybrid simulation systems characteristics. Guidelines are developed to adopt simulation interoperability standards and conceptual modeling techniques using MBSE methods and tools. Domain specific system complexity and behavior can be captured with model-based approaches during the system architecture and functional design requirements definition. MBSE can allow simulation engineers to formally model different aspects of a problem ranging from architectures to corresponding behavioral analysis, to functional decompositions and user requirements (Jobe, 2008)

    JSB Composability and Web Services Interoperability Via Extensible Modeling & Simulation Framework (XMSF), Model Driven Architecture (MDA), Component Repositories, and Web-based Visualization

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    Study Report prepared for the U. S. Air Force, Joint Synthetic Battlespace Analysis of Technical Approaches (ATA) Studies & Prototyping Overview: This paper summarizes research work conducted by organizations concerned with interoperable distributed information technology (IT) applications, in particular the Naval Postgraduate School (NPS) and Old Dominion University (ODU). Although the application focus is distributed modeling & simulation (M&S) the results and findings are in general easily applicable to other distributed concepts as well, in particular the support of operations by M&S applications, such as distributed mission operations. The core idea of this work is to show the necessity of applying open standards for component description, implementation, and integration accompanied by aligned management processes and procedures to enable continuous interoperability for legacy and new M&S components of the live, virtual, and constructive domain within the USAF Joint Synthetic Battlespace (JSB). JSB will be a common integration framework capable of supporting the future emerging simulation needs ranging from training and battlefield rehearsal to research, system development and acquisition in alignment with other operational requirements, such as integration of command and control, support of operations, integration of training ranges comprising real systems, etc. To this end, the study describes multiple complementary Integrated Architecture Framework approaches and shows, how the various parts must be orchestrated in order to support the vision of JSB effectively and efficiently. Topics of direct relevance include Web Services via Extensible Modeling & Simulation Framework (XMSF), the Object Management Group (OMG)’s Model Driven Architecture (MDA), XML-based resource repositories, and Web-based X3D visualization. To this end, the report shows how JSB can − Utilize Web Services throughout all components via XMSF methodologies, − Compose diverse system visualizations using Web-based X3D graphics, − Benefit from distributed modeling methods using MDA, and − Best employ resource repositories for broad and consistent composability. Furthermore, the report recommends the establishment of necessary management organizations responsible for the necessary alignment of management processes and procedures within the JSB as well as with neighbored domains. Continuous interoperability cannot be accomplished by technical standards alone. The application of technical standards targets the implementation level of the system of systems, which results in an interoperable solution valid only for the actual 2 implementation. To insure continuity, the influence of updates, upgrades and introduction of components on the system of systems must be captured in the project management procedures of the participating systems. Finally, the report proposes an exemplifying set of proof-of-capability demonstration prototypes and a five-year technical/institutional transformation plan. All key references are online available at http://www.movesinstitute.org/xmsf/xmsf.html (if not explicitly stated otherwise)

    Supporting the clinical trial recruitment process through the grid

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    Patient recruitment for clinical trials and studies is a large-scale task. To test a given drug for example, it is desirable that as large a pool of suitable candidates is used as possible to support reliable assessment of often moderate effects of the drugs. To make such a recruitment campaign successful, it is necessary to efficiently target the petitioning of these potential subjects. Because of the necessarily large numbers involved in such campaigns, this is a problem that naturally lends itself to the paradigm of Grid technology. However the accumulation and linkage of data sets across clinical domain boundaries poses challenges due to the sensitivity of the data involved that are atypical of other Grid domains. This includes handling the privacy and integrity of data, and importantly the process by which data can be collected and used, and ensuring for example that patient involvement and consent is dealt with appropriately throughout the clinical trials process. This paper describes a Grid infrastructure developed as part of the MRC funded VOTES project (Virtual Organisations for Trials and Epidemiological Studies) at the National e-Science Centre in Glasgow that supports these processes and the different security requirements specific to this domain

    A Generalized Discrete Event System (G-DEVS) Flattened Simulation Structure: Application to High-Level Architecture (HLA) Compliant Simulation of Workflow

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    International audienceThe objective of the paper is to specify a new flattened Generalized Discrete Event System simulation engine structure and the Workflow modeling and simulation environment embedding it. We express first the new flattened simulation structure and give the corresponding transformation functions. We analyze performance tests conducted on this new simulation structure to measure its efficiency. Then, having selected the essential concepts in the elaboration of the Workflow, we present a language of description to define the Workflow processes. Finally, we define a distributed Workflow Reference Model that interfaces components of the Workflow with respect to the High-Level Architecture standard. Today enterprises can take advantage of this platform in the context of networking where interoperability, flexibility, and efficiency are challenging concepts
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