291 research outputs found

    Constructing a reproducible testing environment for distributed Java applications.

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    The emergence of the global Internet, wireless data communications, and the availability of powerful computers is enabling a new generation of distributed and concurrent systems. However, the inherent complexity of such systems introduces many new challenges in system testing and maintenance. One of the major problems in testing such systems is that executions with internal non-deterministic choices make the testing procedure non-repeatable. A natural solution is to artificially force the execution of a program to take desired paths so that a test can be reproduced. However, with geographically distributed processes and heterogeneous platform architectures, distributed systems have imposed new challenges in developing effective techniques for reproducible testing. The goal of this research is to build an environment to automate testing for distributed and concurrent Java applications. We will focus on controlling the order of occurrences of input and remote call events according to a user-specified test scenario, which is composed of input data, a constraint expressed as a partial order over the input and remote call events, and expected output. The testing environment is by itself distributed and does not require source code intrusion into the application under test. With minor changes, the testing components can also be reused in CORBA-based applications implemented in Java.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .W35. Source: Masters Abstracts International, Volume: 42-05, page: 1769. Adviser: Jessica Chen. Thesis (M.Sc.)--University of Windsor (Canada), 2003

    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)

    Aviation System Analysis Capability Executive Assistant Design

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    In this technical document, we describe the design developed for the Aviation System Analysis Capability (ASAC) Executive Assistant (EA) Proof of Concept (POC). We describe the genesis and role of the ASAC system, discuss the objectives of the ASAC system and provide an overview of components and models within the ASAC system, and describe the design process and the results of the ASAC EA POC system design. We also describe the evaluation process and results for applicable COTS software. The document has six chapters, a bibliography, three appendices and one attachment

    A meta-semantic language for smart component-adapters

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    The issues confronting the software development community today are significantly different from the problems it faced only a decade ago. Advances in software development tools and technologies during the last two decades have greatly enhanced the ability to leverage large amounts of software for creating new applications through the reuse of software libraries and application frameworks. The problems facing organizations today are increasingly focused around systems integration and the creation of information flows. Software modeling based on the assembly of reusable components to support software development has not been successfully implemented on a wide scale. Several models for reusable software components have been suggested which primarily address the wiring-level connectivity problem. While this is considered necessary, it is not sufficient to support an automated process of component assembly. Two critical issues that remain unresolved are: (1) semantic modeling of components, and (2) deployment process that supports automated assembly. The first issue can be addressed through domain-based standardization that would make it possible for independent developers to produce interoperable components based on a common set of vocabulary and understanding of the problem domain. This is important not only for providing a semantic basis for developing components but also for the interoperability between systems. The second issue is important for two reasons: (a) eliminate the need for developers to be involved in the final assembly of software components, and (b) provide a basis for the development process to be potentially driven by the user. To resolve the above remaining issues (1) and (2) a late binding mechanism between components based on meta-protocols is required. In this dissertation we address the above issues by proposing a generic framework for the development of software components and an interconnection language, COMPILE, for the specification of software systems from components. The computational model of the COMPILE language is based on late and dynamic binding of the components\u27 control, data, and function properties. The use of asynchronous callbacks for method invocation allows control binding among components to be late and dynamic. Data exchanged between components is defined through the use of a meta- language that can describe the semantics of the information but without being bound to any specific programming language type representation. Late binding to functions is accomplished by maintaining domain-based semantics as component metainformation. This information allows clients of components to map generic requested service to specific functions

    IMMACCS: A Multi-Agent Decision-Support System

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    This report describes work performed by the Collaborative Agent Design Research Center for the US Marine Corps Warfighting Laboratory (MCWL), on the IMMACCS experimental decision-support system. IMMACCS (Integrated Marine Multi-Agent Command and Control System) incorporates three fundamental concepts that distinguish it from existing (i.e., legacy) command and control applications. First, it is a collaborative system in which computer-based agents assist human operators by monitoring, analyzing, and reasoning about events in near real-time. Second, IMMACCS includes an ontological model of the battlespace that represents the behavioral characteristics and relationships among real world entities such as friendly and enemy assets, infrastructure objects (e.g., buildings, roads, and rivers), and abstract notions. This object model provides the essential common language that binds all IMMACCS components into an integrated and adaptive decision-support system. Third, IMMACCS provides no ready made solutions that may not be applicable to the problems that will occur in the real world. Instead, the agents represent a powerful set of tools that together with the human operators can adjust themselves to the problem situations that cannot be predicted in advance. In this respect, IMMACCS is an adaptive command and control system that supports planning, execution and training functions concurrently. The report describes the nature and functional requirements of military command and control, the architectural features of IMMACCS that are designed to support these operational requirements, the capabilities of the tools (i.e., agents) that IMMACCS offers its users, and the manner in which these tools can be applied. Finally, the performance of IMMACCS during the Urban Warrior Advanced Warfighting Experiment held in California in March, 1999, is discussed from an operational viewpoint

    Using XML views to improve data-independence of distributed applications that share data

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    The development and maintenance of distributed software applications that support and make efficient use of heterogeneous networked systems is very challenging. One aspect of the complexity is that these distributed applications often need to access shared data, and different applications sharing the data may have different needs and may access different parts of the data. Maintenance and modification are especially difficult when the underlying structure of the data is changed for new requirements. The eXtensible Markup Language, or XML, has emerged as the universal standard for exchanging and externalizing data. It is also widely used for information modeling in an environment consisting of heterogeneous information sources. CORBA is a distributed object technology allowing applications on heterogeneous platforms to communicate through commonly defined services providing a scalable infrastructure for today\u27s distributed systems. To improve data independence, we propose an approach based on XML standards and the notion of views to develop and modify distributed applications which access shared data. In our approach, we model the shared data using XML, and generate different XML views of the data for different applications according to the DTDs of the XML views and the application logic. When the underlying data structure changes, new views are generated systematically. We adopt CORBA as the distributed architecture in our approach. Our thesis is that: views to support data-independence of distributed computing applications can be generated systematically from application logic, CORBA IDL and XML DTD.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .L86. Source: Masters Abstracts International, Volume: 41-04, page: 1113. Adviser: Richard Frost. Thesis (M.Sc.)--University of Windsor (Canada), 2002

    A Model-Driven Architecture based Evolution Method and Its Application in An Electronic Learning System

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    Software products have been racing against aging problem for most of their lifecycles, and evolution is the most effective and efficient solution to this problem. Model-Driven Architecture (MDA) is a new technique for software product for evolving development and reengineering methods. The main steps for MDA are to establish models in different levels and phases, therefore to solve the challenges of requirement and technology change. However, there is only a standard established by Object Management Group (OMG) but without a formal method and approach. Presently, MDA is widely researched in both industrial and research areas, however, there is still without a smooth approach to realise it especially in electronic learning (e-learning) system due to the following reasons: (1) models’ transformations are hard to realise because of lack of tools, (2) most of existing mature research results are working for business and government services but not education area, and (3) most of existing model-driven researches are based on Model-Driven Development (MDD) but not MDA because of OMG standard’s preciseness. Hence, it is worth to investigate an MDA-based method and approach to improve the existing software development approach for e-learning system. Due to the features of MDA actuality, a MDA-based evolution method and approach is proposed in this thesis. The fundamental theories of this research are OMG’s MDA standard and education pedagogical knowledge. Unified Modelling Language (UML) and Unified Modelling Language Profile are hired to represent the information of software system from different aspects. This study can be divided into three main parts: MDA-based evolution method and approach research, Platform-Independent Model (PIM) to Platform-Specific Model (PSM) transformation development, and MDA-based electronic learning system evolution. Top-down approach is explored to develop models for e-learning system. A transformation approach is developed to generate Computation Independent Model (CIM), Platform-Independent Model (PIM), and Platform-Specific Model (PSM); while a set of transformation rules are defined following MDA standard to support PSM’ s generation. In addition, proposed method is applied in an e-learning system as a case study with the prototype rules support. In the end, conclusions are drawn based on analysis and further research directions are discussed as well. The kernel contributions are the proposed transformation rules and its application in electronic learning system
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