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Steigmiller A.,University of Ulm | Liebig T.,derivo GmbH | Glimm B.,University of Ulm
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

With this contribution we push the boundary of some known optimisations such as caching to the very expressive Description Logic . The developed method is based on a sophisticated dependency management and a precise unsatisfiability caching technique, which further enables better informed tableau backtracking and more efficient pruning. Additionally, we optimise the handling of cardinality restrictions, by introducing a strategy called pool-based merging. We empirically evaluate the proposed optimisations within the novel reasoning system Konclude and show that the proposed optimisations indeed result in significant performance improvements. © 2012 Springer-Verlag. Source


Steigmiller A.,University of Ulm | Liebig T.,derivo GmbH | Glimm B.,University of Ulm
Journal of Web Semantics | Year: 2014

This paper introduces Konclude, a high-performance reasoner for the Description Logic SROIQV. The supported ontology language is a superset of the logic underlying OWL 2 extended by nominal schemas, which allows for expressing arbitrary DL-safe rules. Konclude's reasoning core is primarily based on the well-known tableau calculus for expressive Description Logics. In addition, Konclude also incorporates adaptations of more specialised procedures, such as consequence-based reasoning, in order to support the tableau algorithm. Konclude is designed for performance and uses well-known optimisations such as absorption or caching, but also implements several new optimisation techniques. The system can furthermore take advantage of multiple CPU's at several levels of its processing architecture. This paper describes Konclude's interface options, reasoner architecture, processing workflow, and key optimisations. Furthermore, we provide results of a comparison with other widely used OWL 2 reasoning systems, which show that Konclude performs eminently well on ontologies from any language fragment of OWL 2. © 2014 Elsevier B.V. Source


Steigmiller A.,University of Ulm | Glimm B.,University of Ulm | Liebig T.,derivo GmbH
Journal of Automated Reasoning | Year: 2014

Nominal schemas have recently been introduced as a new approach for the integration of DL-safe rules into the Description Logic framework. The efficient processing of knowledge bases with nominal schemas remains, however, challenging. We address this by extending the well-known optimisation of absorption as well as the standard tableau calculus to directly handle the (absorbed) nominal schema axioms. We implement the resulting extension of standard tableau calculi in the novel reasoning system Konclude and present further optimisations. In our empirical evaluation, we show the effect of these optimisations and we find that the proposed nominal schema handling performs well even when compared to (hyper)tableau systems with dedicated rule support. © 2014, Springer Science+Business Media Dordrecht. Source


Steigmiller A.,University of Ulm | Glimm B.,University of Ulm | Liebig T.,derivo GmbH
CEUR Workshop Proceedings | Year: 2013

Nominal schemas have recently been introduced as a new approach for the integration of DL-safe rules into the Description Logic framework. The efficient processing of knowledge bases with nominal schemas remains, however, challenging. We address this by extending the well-known optimisation of absorption as well as the standard tableau calculus to directly handle the (absorbed) nominal schema axioms. We implement the resulting extension of standard tableau calculi in a novel reasoning system and we integrate further optimisations. In our empirical evaluation, we show the effect of these optimisations and we find that the proposed approach performs well even when compared to other DL reasoners with dedicated rule support. Source


Steigmiller A.,University of Ulm | Glimm B.,University of Ulm | Liebig T.,derivo GmbH
IJCAI International Joint Conference on Artificial Intelligence | Year: 2013

Nominal schemas have recently been introduced as a new approach for the integration of DL-safe rules into the Description Logic framework. The efficient processing of knowledge bases with nominal schemas remains, however, challenging. We address this by extending the well-known optimisation of absorption as well as the standard tableau calculus to directly handle the (absorbed) nominal schema axioms. We implement the resulting extension of standard tableau calculi in a novel reasoning system and we integrate further optimisations. In our empirical evaluation, we show the effect of these optimisations and we find that the proposed approach performs well even when compared to other DL reasoners with dedicated rule support. Source

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