2,145 research outputs found
Two-Sorted Metric Temporal Logic
No full textTemporal logic has been successfully used for modeling and analyzing the behavior of reactive and concurrent systems. Standard temporal logic is inadequate for real-time applications because it only deals with qualitative timing properties. This is overcome by metric temporal logics which offer a uniform logical framework in which both qualitative and quantitative timing properties can be expressed by making use of a parameterized operator of relative temporal realization. In this paper we deal with completeness issues for basic systems of metric temporal logic -despite their relevance, such issues have been ignored or only partially addressed in the literature. We view metric temporal logics as two-sorted formalisms having formulae ranging over time instants and parameters ranging over an (ordered) abelian group of temporal displacements. We first provide an axiomatization of the pure metric fragment of the logic, and prove its soundness and completeness. Then, we show how to obtain the metric temporal logic of linear orders by adding an ordering over displacements. Finally, we consider general metric temporal logics allowing quantification over algebraic variables and free mixing of algebraic formulae and temporal prepositional symbols
Model checking for hybrid logics (with an application to semistructured data)
No full textWe investigate the complexity of the model checking problem for hybrid logics. We provide model checking algorithms for various hybrid fragments and we prove PSPACE-completeness for hybrid fragments including binders. We complement and motivate our complexity results with an application of model checking in hybrid logic to the problems of query and constraint evaluation for semistructured data
Length Normalization in XML Retrieval
Full text linkThe full paper appeared as: J. Kamps, M. de Rijke, and B. Sigurbj¨ornsson,
“Length Normalization in XML Retrieval,” In: Proceedings 27th Annual
International ACM SIGIR Conference (SIGIR 2004), pages 80-87, 2004.
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