Michael Siegel

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Large organizations need to exchange information among many separately developed systems. In order for this exchange to be useful, the individual systems must agree on the meaning of their exchanged data. That is, the organization must ensure <italic>semantic interoperability</italic>. This paper provides a theory of <italic>semantic values</italic> as a(More)
The <italic>Context Interchange strategy</italic> presents a novel perspective for mediated data access in which semantic conflicts among heterogeneous systems are not identified a priori, but are detected and reconciled by a <italic>context mediator</italic> through comparison of <italic>contexts axioms</italic> corresponding to the systems engaged in data(More)
We present the notion of translation validation as a new approach to the veriication of translators (compilers, code generators). Rather than proving in advance that the compiler always produces a target code which correctly implements the source code (compiler verii-cation), each individual translation (i.e. a run of the compiler) is followed by a(More)
Research in database interoperability has primarily focused on circumventing schematic and semantic incompatibility arising from autonomy of the underlying databases. We argue that, while existing integration strategies might provide satisfactory support for small or static systems, their inadequacies rapidly become evident in large-scale interoperable(More)
We describe CVT – a fully automatic tool for code validation, i.e., verifying that the target code produced by a code-generator (equivalently, a compiler or a translator) is a correct implementation of the source specification. This approach is a viable alternative to a full formal verification of the code-generator program, and has the advantage of not(More)
The use of inference rules to support intelligent data processing is an increasingly important tool in many areas of computer science. In database systems, rules are used in semantic query optimization as a method for reducing query processing costs. The savings is dependent on the ability of experts to supply a set of useful rules and the ability of the(More)
The issue of harm reduction has long been controversial in the public health practice of tobacco control. Health advocates have been reluctant to endorse a harm reduction approach out of fear that tobacco companies cannot be trusted to produce and market products that will reduce the risks associated with tobacco use. Recently, companies independent of the(More)