In this paper we explore embeddings of the various kinds of RDF entailment in F-logic. We show that the embeddings of simple, RDF, and RDFS entailment, as well as a large fragment of extensional RDFS entailment, fall ...
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In this paper we explore embeddings of the various kinds of RDF entailment in F-logic. We show that the embeddings of simple, RDF, and RDFS entailment, as well as a large fragment of extensional RDFS entailment, fall in the Datalog fragment of F-logic, allowing the use of optimization techniques from the area of deductive databases for reasoning with RDF. Using earlier results on the relationship between F-logic and Description logics (DLs), we define an embedding of a large fragment of extensional RDFS in a tractable description logic, namely DL-Lite, allowing efficient reasoning over the ontology vocabulary. We show how, using these embeddings, RDFS can be extended with rules and/or general axioms.
Integrity checking is aimed at determining whether an operation execution violates a given integrity constraint. To perform this computation efficiently, several incremental methods have been developed. the main goal ...
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ISBN:
(数字)9783540346531
ISBN:
(纸本)354034652X
Integrity checking is aimed at determining whether an operation execution violates a given integrity constraint. To perform this computation efficiently, several incremental methods have been developed. the main goal of these methods is to consider as few of the entities in an information base as possible, which is generally achieved by reasoning from the structural events that define the effect of the operations. In this paper, we propose a new method for dealing withthe incremental evaluation of the OCL integrity constraints specified in UML conceptual schemas. Since our method works at a conceptual level, its results are useful in efficiently evaluating constraints regardless of the technology platform in which the conceptual schema is to be implemented.
the proceedings contains 18 papers. the topics discussed include: equational constraint solving via a restricted form of universal quantification;modeling the evolution of objects in temporal information systems;on th...
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ISBN:
(纸本)3540317821
the proceedings contains 18 papers. the topics discussed include: equational constraint solving via a restricted form of universal quantification;modeling the evolution of objects in temporal information systems;on the number of functional dependencies;solving abduction by computing joint explanations: logic;the nested list normal form for functional and multivalued dependencies;axiomatising functional dependencies for XML with frequencies;guarded open answer set programming with generalized literals;consistency checking algorithms for restricted UML class diagrams;on multivalued dependencies in fixed and undetermined universes;processing ranked queries withthe minimum space;and hybrid minimal spanning tree and mixture of Gaussians based clustering algorithm.
作者：
Barták, RCharles Univ
Fac Math & Phys Inst Theoret Comp Sci Prague Czech Republic
constraintprogramming provides a declarative approach to solving combinatorial (optimization) problems. the user just states the problem as a constraint satisfaction problem (CSP) and a generic solver finds a solutio...
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ISBN:
(纸本)3540255605
constraintprogramming provides a declarative approach to solving combinatorial (optimization) problems. the user just states the problem as a constraint satisfaction problem (CSP) and a generic solver finds a solution without additional programming. However, in practice, the situation is more complicated because there usually exist several ways how to model the problem as a CSP, that is using variables, their domains, and constraints. In fact, different constraint models may lead to significantly different running times of the solver so constraint modeling is a crucial part of problem solving. this paper describes some known approaches to efficient modeling withconstraints in a tutorial-like form. the primary audience is practitioners, especially in logicprogramming, that would like to use constraints in their projects but do not have yet deep knowledge of constraint satisfaction techniques.
the proceedings contain 19 pages. the topics discussed include: declaratively querying and visualizing knowledge bases in XML;incremental learning of transfer rules for customized machine translation;an evaluation of ...
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ISBN:
(纸本)3540255605
the proceedings contain 19 pages. the topics discussed include: declaratively querying and visualizing knowledge bases in XML;incremental learning of transfer rules for customized machine translation;an evaluation of a rule based language for classification queries;mining semantic structures in movies;solving alternating boolean equation systems in answer set programming;effective modeling withconstraints;a local search system for solving constraint problems of declarative graph based global constraints;realizing the alternative resources constraint;distributed constraint-based railway simulation;concurrent engineering to wisdom engineering;and a pragmatic approach to pre-testing Prolog programs.
In railway simulation, given timetables have to be checked against various criteria, mainly correctness and robustness. Most existing approaches use classical centralized simulation techniques. this work goes beyond t...
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ISBN:
(纸本)3540255605
In railway simulation, given timetables have to be checked against various criteria, mainly correctness and robustness. Most existing approaches use classical centralized simulation techniques. this work goes beyond that in two main aspects: We use constraint satisfaction to get rid of deadlock problems and the simulation is done distributedly for better performance. this should make it possible to solve very large railway simulation problems.
Alternative resource constraint problems have to be solved in practical applications where several resources are available for the activities to be scheduled. In this paper, we present a modular approach to solve such...
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ISBN:
(纸本)3540255605
Alternative resource constraint problems have to be solved in practical applications where several resources are available for the activities to be scheduled. In this paper, we present a modular approach to solve such problems which is based on single resource constraints. Furthermore, we present a new sweeping algorithm which performs some "global" overload checking for the alternative resource constraint problem. To our knowledge, this is the first presentation where "sweeping", a well-known technique in computational geometry, was used to perform this checking efficiently. For a practical evaluation of our approach, we implemented and integrated it into our Java constraint engine firstcs. We compared our implementation withthe more general disjoint2 constraint in SICS-tus Prolog on some benchmark problems: the publicly available random placement problems (RPP).
Over the last few years, we have been developing the configuration model ConBaCon, which is based on constraintprogramming over finite domains. the model is sound and suitable for building efficient and flexible syst...
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ISBN:
(纸本)3540255605
Over the last few years, we have been developing the configuration model ConBaCon, which is based on constraintprogramming over finite domains. the model is sound and suitable for building efficient and flexible systems that fulfill all the requirements of advanced configuration systems. In this paper, we present model extensions that enable time-extended configuration and reconfiguration problems to be solved: Besides "normal" configuration and reconfiguration problems, the extended model can now also solve problems that contain time-dependent resource availbilities or supply constraints for the ground components included. the general nature of the model extensions introduced seems to be suitable for integration in other (commercial) constraint-based configuration systems/configurator libraries as well.
In this paper we present a local search constraint solver in which constraints are expressed using cost functions on graph structures of filter constraints of equal type. A similar theoretical approach has previously ...
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ISBN:
(纸本)3540255605
In this paper we present a local search constraint solver in which constraints are expressed using cost functions on graph structures of filter constraints of equal type. A similar theoretical approach has previously been used to model a large number of complex global constraints, which motivates the use of such a model in practice. In a local search context, we view global constraints as complex cost functions, encapsulating the structure of the constraints using a graph of variables, values and filter constraints. this representation gives us a declarative model, which can also be used to efficiently compute a cost as well as conflict levels of the variables in the constraints. We have implemented these ideas in a compositional C++ framework called COMPOSER, which can be used to solve systems of graph-based constraints. We demonstrate the usability of this approach on several well-known global constraints, and show by experimental results on two problems that an approach using a graph basis for global constraint modeling is not only possible in practice, but also competitive with existing constraint-based local search systems.
In this paper we apply answer set programming to solve alternating Boolean equation systems. We develop a novel characterization of solutions for variables in disjunctive and conjunctive Boolean equation systems. Base...
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ISBN:
(纸本)3540255605
In this paper we apply answer set programming to solve alternating Boolean equation systems. We develop a novel characterization of solutions for variables in disjunctive and conjunctive Boolean equation systems. Based on this we devise a mapping from Boolean equation systems with alternating fixed points to normal logic programs such that the solution of a given variable of an equation system can be determined by the existence of a stable model of the corresponding logic program. the technique can be used to model check alternating formulas of modal mu-calculus.
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