716,891 research outputs found

    Characteristics of the Audit Processes for Distributed Informatics Systems

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    The paper contains issues regarding: main characteristics and examples of the distributed informatics systems and main difference categories among them, concepts, principles, techniques and fields for auditing the distributed informatics systems, concepts and classes of the standard term, characteristics of this one, examples of standards, guidelines, procedures and controls for auditing the distributed informatics systems. The distributed informatics systems are characterized by the following issues: development process, resources, implemented functionalities, architectures, system classes, particularities. The audit framework has two sides: the audit process and auditors. The audit process must be led in accordance with the standard specifications in the IT&C field. The auditors must meet the ethical principles and they must have a high-level of professional skills and competence in IT&C field.informatics audit, characteristic, distributed informatics system, standard

    Guidelines for Software Development for Decision Support Systems

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    One of the activities of the System and Decision Sciences Program is the collaboration with scientists and institutes from different countries and with other programs and projects at IIASA in the field of Methodology of Decision Analysis. The main results of these activities are the development of theory, methodology and software for Decision Support Systems. A considerable amount of experience and software has been accumulated for over ten years of this type of cooperation. However, the analysis of the results of software development activities indicates the need for setting and observing some specified Guidelines for Software Development. This Working Paper contains a first version of such Guidelines which is the result of discussions with software developers. The draft of this Working Paper has been distributed for comments to about hundred scientists involved in development of software for Decision Support Systems. Since no reservations for the proposed Guidelines have been communicated to the author, one can assume that there is a general agreement for setting these Guidelines as a working scheme for the development of software for Decision Support Systems within the cooperation with the System and Decision Sciences Program. Although the Guidelines are oriented for a specific type of software, most of them can and should be observed in the development of any kind of software

    Redundancy management for efficient fault recovery in NASA's distributed computing system

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    The management of redundancy in computer systems was studied and guidelines were provided for the development of NASA's fault-tolerant distributed systems. Fault recovery and reconfiguration mechanisms were examined. A theoretical foundation was laid for redundancy management by efficient reconfiguration methods and algorithmic diversity. Algorithms were developed to optimize the resources for embedding of computational graphs of tasks in the system architecture and reconfiguration of these tasks after a failure has occurred. The computational structure represented by a path and the complete binary tree was considered and the mesh and hypercube architectures were targeted for their embeddings. The innovative concept of Hybrid Algorithm Technique was introduced. This new technique provides a mechanism for obtaining fault tolerance while exhibiting improved performance

    Distributed and Centralized Task Allocation: When and Where to Use Them

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    Self-organisation is frequently advocated as the solution for managing large, dynamic systems. Distributed algorithms are implicitly designed for infinitely large problems, while small systems are regarded as being controllable using traditional, centralised approaches. Many real-world systems, however, do not fit conveniently into these "small" or "large" categories, resulting in a range of cases where the optimal solution is ambiguous. This difficulty is exacerbated by enthusiasts of either approach constructing problems that suit their preferred control architecture. We address this ambiguity by building an abstract model of task allocation in a community of specialised agents. We are inspired by the problem of work distribution in distributed satellite systems, but the model is also relevant to the resource allocation problems in distributed robotics, autonomic computing and wireless sensor networks. We compare the behaviour of a self-organising, market-based task allocation strategy to a classical approach that uses a central controller with global knowledge. The objective is not to prove one mechanism inherently superior to the other; instead we are interested in the regions of problem space where each of them dominates. Simulation is used to explore the trade-off between energy consumption and robustness in a system of intermediate size, with fixed communication costs and varying rates of component failure. We identify boundaries between regions in the parameter space where one or the other architecture will be favoured. This allows us to derive guidelines for system designers, thus contributing to the development of a disciplined approach to controlling distributed systems using self-organising mechanisms

    The Joint COntrols Project Framework

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    The Framework is one of the subprojects of the Joint COntrols Project (JCOP), which is collaboration between the four LHC experiments and CERN. By sharing development, this will reduce the overall effort required to build and maintain the experiment control systems. As such, the main aim of the Framework is to deliver a common set of software components, tools and guidelines that can be used by the four LHC experiments to build their control systems. Although commercial components are used wherever possible, further added value is obtained by customisation for HEP-specific applications. The supervisory layer of the Framework is based on the SCADA tool PVSS, which was selected after a detailed evaluation. This is integrated with the front-end layer via both OPC (OLE for Process Control), an industrial standard, and the CERN-developed DIM (Distributed Information Management System) protocol. Several components are already in production and being used by running fixed-target experiments at CERN as well as for the LHC experiment test beams. The paper will give an overview of the key concepts behind the project as well as the state of the current development and future plans.Comment: Paper from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, PDF. PSN THGT00

    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)

    Designing Sustainability for All

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    This open access book introduces design for Sustainable Product-Service Systems (S.PSS) and for Sustainable Distributed Economies (S.DE). These are introduced as technical and operative tools for the development of a new generation of designers, responsible and capable of designing environmentally, socially and economically sustainable solutions, accessible to all. The book provides a comprehensive framework and also practical tools to support the system design for sustainability process. It overviews methodologies, tools and strategies for Sustainable PSS design applied to Distributed Economies (DE) and provides strategies and design guidelines. All of these are highlighted and expanded upon with international case studies

    A review of GIS-based information sharing systems

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    GIS-based information sharing systems have been implemented in many of England and Wales' Crime and Disorder Reduction Partnerships (CDRPs). The information sharing role of these systems is seen as being vital to help in the review of crime, disorder and misuse of drugs; to sustain strategic objectives, to monitor interventions and initiatives; and support action plans for service delivery. This evaluation into these systems aimed to identify the lessons learned from existing systems, identify how these systems can be best used to support the business functions of CDRPs, identify common weaknesses across the systems, and produce guidelines on how these systems should be further developed. At present there are in excess of 20 major systems distributed across England and Wales. This evaluation considered a representative sample of ten systems. To date, little documented evidence has been collected by the systems that demonstrate the direct impact they are having in reducing crime and disorder, and the misuse of drugs. All point to how they are contributing to more effective partnership working, but all systems must be encouraged to record how they are contributing to improving community safety. Demonstrating this impact will help them to assure their future role in their CDRPs. By reviewing the systems wholly, several key ingredients were identified that were evident in contributing to the effectiveness of these systems. These included the need for an effective partnership business model within which the system operates, and the generation of good quality multi-agency intelligence products from the system. In helping to determine the future development of GIS-based information sharing systems, four key community safety partnership business service functions have been identified that these systems can most effectively support. These functions support the performance review requirements of CDRPs, operate a problem solving scanning and analysis role, and offer an interface with the public. By following these business service functions as a template will provide for a more effective application of these systems nationally

    Designing Sustainability for All

    Get PDF
    This open access book introduces design for Sustainable Product-Service Systems (S.PSS) and for Sustainable Distributed Economies (S.DE). These are introduced as technical and operative tools for the development of a new generation of designers, responsible and capable of designing environmentally, socially and economically sustainable solutions, accessible to all. The book provides a comprehensive framework and also practical tools to support the system design for sustainability process. It overviews methodologies, tools and strategies for Sustainable PSS design applied to Distributed Economies (DE) and provides strategies and design guidelines. All of these are highlighted and expanded upon with international case studies
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