15,524 research outputs found

    A Proof Strategy Language and Proof Script Generation for Isabelle/HOL

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    We introduce a language, PSL, designed to capture high level proof strategies in Isabelle/HOL. Given a strategy and a proof obligation, PSL's runtime system generates and combines various tactics to explore a large search space with low memory usage. Upon success, PSL generates an efficient proof script, which bypasses a large part of the proof search. We also present PSL's monadic interpreter to show that the underlying idea of PSL is transferable to other ITPs.Comment: This paper has been submitted to CADE2

    A comparison of the finite difference and finite element methods for heat transfer calculations

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    The finite difference method and finite element method for heat transfer calculations are compared by describing their bases and their application to some common heat transfer problems. In general it is noted that neither method is clearly superior, and in many instances, the choice is quite arbitrary and depends more upon the codes available and upon the personal preference of the analyst than upon any well defined advantages of one method. Classes of problems for which one method or the other is better suited are defined

    Seismic Vulnerability of the Italian Roadway Bridge Stock

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    This study focuses on the seismic vulnerability evaluation of the Italian roadway bridge stock, within the framework of a Civil Protection sponsored project. A comprehensive database of existing bridges (17,000 bridges with different level of knowledge) was implemented. At the core of the study stands a procedure for automatically carrying out state-of-the-art analytical evaluation of fragility curves for two performance levels – damage and collapse – on an individual bridge basis. A webGIS was developed to handle data and results. The main outputs are maps of bridge seismic risk (from the fragilities and the hazard maps) at the national level and real-time scenario damage-probability maps (from the fragilities and the scenario shake maps). In the latter case the webGIS also performs network analysis to identify routes to be followed by rescue teams. Consistency of the fragility derivation over the entire bridge stock is regarded as a major advantage of the adopted approach

    Applying knowledge compilation techniques to model-based reasoning

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    Researchers in the area of knowledge compilation are developing general purpose techniques for improving the efficiency of knowledge-based systems. In this article, an attempt is made to define knowledge compilation, to characterize several classes of knowledge compilation techniques, and to illustrate how some of these techniques can be applied to improve the performance of model-based reasoning systems

    Design for manufacturability : re-design of pencil sharpener for the ease of assembly

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    A Design For Manufacturability (DFM) approach is used to analyze the existing design of a pencil sharpener, and to reduce and re-design the parts of pencil sharpener for the ease of assembly. The procedure for the selection of a suitable and economical assembly method is based on the Boothroyd and Dewhurst methods. Analysis of the initial design for manual assembly and re-design for automatic as well as manual assembly is presented. An algorithmic approach for simplified generation of all mechanical assembly sequences and selection of the assembly sequences is presented using De Fazio and Whitney approach
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