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Telos: representing knowledge about information systems
We describe Telos, a language intended to support the development of information systems. The design principles for the language are based on the premise that information system development isExpand
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Backtracking algorithms for disjunctions of temporal constraints
We extend the framework of simple temporal problems studied originally by Dechter, Meiri and Pearl to consider constraints of the form x1 - y1 ? r1 V... V xn - yn ? rn where x1... xn, y1... yn areExpand
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Composing Cardinal Direction Relations
We study the recent proposal of Goyal and Egenhofer who presented a model for qualitative spatial reasoning about cardinal directions. Our approach is formal and complements the presentation of GoyalExpand
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On the consistency of cardinal direction constraints
We present a formal model for qualitative spatial reasoning with cardinal directions utilizing a co-ordinate system. Then, we study the problem of checking the consistency of a set of cardinalExpand
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Evaluating Conjunctive Triple Pattern Queries over Large Structured Overlay Networks
We study the problem of evaluating conjunctive queries composed of triple patterns over RDF data stored in distributed hash tables. Our goal is to develop algorithms that scale to large amounts ofExpand
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Strabon: A Semantic Geospatial DBMS
We present Strabon, a new RDF store that supports the state of the art semantic geospatial query languages stSPARQL and GeoSPARQL. To illustrate the expressive power offered by these query languagesExpand
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Composing cardinal direction relations
We study the recent proposal of Goyal and Egenhofer who presented a model for qualitative spatial reasoning about cardinal directions. Our approach is formal and complements the presentation of GoyalExpand
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Tractable Disjunctions of Linear Constraints
We study the problems of deciding consistency and performing variable elimination for disjunctions of linear inequalities and inequations with at most one inequality per disjunction. This new classExpand
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A formal framework for business process modelling and design
We present a formal framework for enterprise and business process modelling. The concepts of our framework (objectives and goals, roles and actors, actions and processes, responsibilities andExpand
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