70,221 research outputs found

    Exploiting the Hierarchical Structure of Rule-Based Specifications for Decision Planning

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    Rule-based specifications have been very successful as a declarative approach in many domains, due to the handy yet solid foundations offered by rule-based machineries like term and graph rewriting. Realistic problems, however, call for suitable techniques to guarantee scalability. For instance, many domains exhibit a hierarchical structure that can be exploited conveniently. This is particularly evident for composition associations of models. We propose an explicit representation of such structured models and a methodology that exploits it for the description and analysis of model- and rule-based systems. The approach is presented in the framework of rewriting logic and its efficient implementation in the rewrite engine Maude and is illustrated with a case study.

    An ontology framework for developing platform-independent knowledge-based engineering systems in the aerospace industry

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    This paper presents the development of a novel knowledge-based engineering (KBE) framework for implementing platform-independent knowledge-enabled product design systems within the aerospace industry. The aim of the KBE framework is to strengthen the structure, reuse and portability of knowledge consumed within KBE systems in view of supporting the cost-effective and long-term preservation of knowledge within such systems. The proposed KBE framework uses an ontology-based approach for semantic knowledge management and adopts a model-driven architecture style from the software engineering discipline. Its phases are mainly (1) Capture knowledge required for KBE system; (2) Ontology model construct of KBE system; (3) Platform-independent model (PIM) technology selection and implementation and (4) Integration of PIM KBE knowledge with computer-aided design system. A rigorous methodology is employed which is comprised of five qualitative phases namely, requirement analysis for the KBE framework, identifying software and ontological engineering elements, integration of both elements, proof of concept prototype demonstrator and finally experts validation. A case study investigating four primitive three-dimensional geometry shapes is used to quantify the applicability of the KBE framework in the aerospace industry. Additionally, experts within the aerospace and software engineering sector validated the strengths/benefits and limitations of the KBE framework. The major benefits of the developed approach are in the reduction of man-hours required for developing KBE systems within the aerospace industry and the maintainability and abstraction of the knowledge required for developing KBE systems. This approach strengthens knowledge reuse and eliminates platform-specific approaches to developing KBE systems ensuring the preservation of KBE knowledge for the long term

    Exploiting rules and processes for increasing flexibility in service composition

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    Recent trends in the use of service oriented architecture for designing, developing, managing, and using distributed applications have resulted in an increasing number of independently developed and physically distributed services. These services can be discovered, selected and composed to develop new applications and to meet emerging user requirements. Service composition is generally defined on the basis of business processes in which the underlying composition logic is guided by specifying control and data flows through Web service interfaces. User demands as well as the services themselves may change over time, which leads to replacing or adjusting the composition logic of previously defined processes. Coping with change is still one of the fundamental problems in current process based composition approaches. In this paper, we exploit declarative and imperative design styles to achieve better flexibility in service composition

    Exploiting Qualitative Information for Decision Support in Scenario Analysis

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    The development of scenario analysis (SA) to assist decision makers and stakeholders has been growing over the last few years through mainly exploiting qualitative information provided by experts. In this study, we present SA based on the use of qualitative data for strategy planning. We discuss the potential of SA as a decision-support tool, and provide a structured approach for the interpretation of SA data, and an empirical validation of expert evaluations that can help to measure the consistency of the analysis. An application to a specific case study is provided, with reference to the European organic farming business

    A canonical theory of dynamic decision-making

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    Decision-making behavior is studied in many very different fields, from medicine and eco- nomics to psychology and neuroscience, with major contributions from mathematics and statistics, computer science, AI, and other technical disciplines. However the conceptual- ization of what decision-making is and methods for studying it vary greatly and this has resulted in fragmentation of the field. A theory that can accommodate various perspectives may facilitate interdisciplinary working. We present such a theory in which decision-making is articulated as a set of canonical functions that are sufficiently general to accommodate diverse viewpoints, yet sufficiently precise that they can be instantiated in different ways for specific theoretical or practical purposes. The canons cover the whole decision cycle, from the framing of a decision based on the goals, beliefs, and background knowledge of the decision-maker to the formulation of decision options, establishing preferences over them, and making commitments. Commitments can lead to the initiation of new decisions and any step in the cycle can incorporate reasoning about previous decisions and the rationales for them, and lead to revising or abandoning existing commitments. The theory situates decision-making with respect to other high-level cognitive capabilities like problem solving, planning, and collaborative decision-making. The canonical approach is assessed in three domains: cognitive and neuropsychology, artificial intelligence, and decision engineering

    "Obedient Servant or Runaway Eurocracy? Delegation, Agency, and Agenda Setting in the European Community"

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    Do supranational institutions matter - do they deserve the status of an independent causal variable - in EC policymaking? Does the Commission matter? Does the European Court of Justice? Does the European Parliament? Is the European Community characterized by continued member state dominance, or by a runaway Commission and an activist Court progressively chipping away at this dominance? These are some of the most important questions for our understanding of the European Community and of European integration, and have divided the two traditional schools of thought in regional integration, with neofunctionalists [Haas 1958; Lindberg & Scheingold 1970] generally asserting, and intergovernmentalists [Hoffmann 1966; Taylor 1983; Moravcsik 1991, 1993] generally denying, any important causal role for supranational institutions in the integration process. By and large, however, neither neofunctionalism nor intergovernmentalism1 has generated testable hypotheses regarding the conditions under which, and the ways in which, supranational institutions exert an independent causal influence on either EC governance or the process of European integration. This paper presents a unified theoretical approach to the problem of supranational influence, based largely on the new institutionalism in rational choice theory. Simplifying only slightly, this new literature can be traced to Shepsle's [1979] pioneering work on the role of institutions in the US Congress. Beginning with the observation by McKelvey [1976], Riker [1980] and others that, in a system of majoritarian decisionmaking, policy choices are inherently unstable, "cycling" among multiple possible equilibria, Shepsle argued that Congressional institutions, and in particular the committee system, could produce structure-induced equilibrium, by ruling some policy alternatives as permissible or impermissible, and by structuring the voting and veto power of the various actors in the decisionmaking process

    Corporate strategy revisited: A view from complexity theory

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    Despite its long tradition and well known contributions, corporate strategy research is yet far from being mature. This paper proposes an innovative framework that approaches the field from the theoretical perspective provided by complexity theory. We propose to see the corporate level of the organization as the driver, pacer and framer of the overall firm's evolution process. Drive is provided by the cognitive representation of the corporate fitness landscape that is implicit in the firm's corporate plan. Pacing is a consequence of the kind of strategic initiatives ("search strategy") developed by the company. Framing is achieved through the architectural design that the corporate level implements for the firm.corporate strategy; complexity theory; self-organizing;
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