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Computing the Least Common Subsumer w.r.t. a Background Terminology
 Journal of Applied Logic
, 2004
"... Methods for computing the least common subsumer (lcs) are usually restricted to rather inexpressive DLs whereas existing knowledge bases are written in very expressive DLs. In order to allow the user to reuse concepts defined in such terminologies and still support the definition of new concepts ..."
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Cited by 37 (9 self)
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Methods for computing the least common subsumer (lcs) are usually restricted to rather inexpressive DLs whereas existing knowledge bases are written in very expressive DLs. In order to allow the user to reuse concepts defined in such terminologies and still support the definition of new concepts by computing the lcs, we extend the notion of the lcs of concept descriptions to the notion of the lcs w.r.t. a background terminology.
Approximation and difference in description logics
 Proc. of KR02
, 2002
"... Approximation is a new inference service in Description Logics first mentioned by Baader, Küsters, and Molitor. Approximating a concept, defined in one Description Logic, means to translate this concept to another concept, defined in a second typically less expressive Description Logic, such that bo ..."
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Cited by 29 (6 self)
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Approximation is a new inference service in Description Logics first mentioned by Baader, Küsters, and Molitor. Approximating a concept, defined in one Description Logic, means to translate this concept to another concept, defined in a second typically less expressive Description Logic, such that both concepts are as closely related as possible with respect to subsumption. The present paper provides the first indepth investigation of this inference task. We prove that approximations from the Description Logic ALC to ALE always exist and propose an algorithm computing them. As a measure for the accuracy of the approximation, we introduce a syntaxoriented difference operator, which yields a concept that contains all aspects of the approximated concept that are not present in the approximation. It is also argued that a purely semantical difference operator, as introduced by Teege, is less suited for this purpose. Finally, for the logics under consideration, we propose an algorithm computing the difference.
Functional Modeling of Engineering Designs for the Semantic Web
 IEEE Data Engineering Bulletin
, 2003
"... A goal of this paper is to briefly describe work on a novel application of the Semantic Web to design repositoriescollections of diverse engineering knowledge with sophisticated reasoning services. However, a more general goal of this paper is to demonstrate the extra utility enabled in database ..."
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Cited by 16 (1 self)
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A goal of this paper is to briefly describe work on a novel application of the Semantic Web to design repositoriescollections of diverse engineering knowledge with sophisticated reasoning services. However, a more general goal of this paper is to demonstrate the extra utility enabled in databasestyled applications by the incorporation of even simple semantics. It also discusses the development of practical, useful representations and applications for the Semantic Web.
Approximating Most Specific Concepts in Description Logics with Existential Restrictions
, 2001
"... . Computing the most specic concept (msc) is an inference task that allows to abstract from individuals dened in description logic (DL) knowledge bases. For DLs that allow for existential restrictions or number restrictions, however, the msc need not exist unless one allows for cyclic concepts i ..."
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Cited by 16 (0 self)
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. Computing the most specic concept (msc) is an inference task that allows to abstract from individuals dened in description logic (DL) knowledge bases. For DLs that allow for existential restrictions or number restrictions, however, the msc need not exist unless one allows for cyclic concepts interpreted with the greatest xedpoint semantics. Since such concepts cannot be handled by current DLsystems, we propose to approximate the msc. We show that for the DL ALE , which has concept conjunction, a restricted form of negation, existential restrictions, and value restrictions as constructors, approximations of the msc always exist and can eectively be computed. 1
Approximating ALCNConcept Descriptions
"... Approximating a concept, de ned in one DL, means to translate this concept to another concept, de ned in a second typically less expressive DL, such that both concepts are as closely related as possible with respect to subsumption. In a previous work, we have provided an algorithm for approxim ..."
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Cited by 8 (4 self)
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Approximating a concept, de ned in one DL, means to translate this concept to another concept, de ned in a second typically less expressive DL, such that both concepts are as closely related as possible with respect to subsumption. In a previous work, we have provided an algorithm for approximating ALCconcept descriptions by ALEconcept descriptions. In the present paper, motivated by an application in chemical process engineering, we extend this result by taking number restrictions into account.
Sonic  Nonstandard inferences go OilEd
 IN PROCEEDINGS OF THE INTERNATIONAL JOINT CONFERENCE ON AUTOMATED REASONING IJCAR’04, LNAI
, 2004
"... Sonic 1 is the first prototype implementation of nonstandard inferences for Description Logics usable via a graphical user interface. The contribution of our implementation is twofold: it extends an earlier implementation of the least common subsumer and of the approximation inference to number res ..."
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Cited by 7 (5 self)
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Sonic 1 is the first prototype implementation of nonstandard inferences for Description Logics usable via a graphical user interface. The contribution of our implementation is twofold: it extends an earlier implementation of the least common subsumer and of the approximation inference to number restrictions, and it offers these reasoning services via an extension of the graphical ontology editor OilEd [3].
Structural subsumption and least common subsumers in a description logic with existential and number restrictions
 Studia Logica
"... Abstract. The least common subsumer (lcs) of a set of concept descriptions is the most specific concept description that subsumes all of the concept descriptions in the given set. By computing the lcs, commonalities between concept descriptions can be made explicit. This is an important inference ta ..."
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Cited by 6 (0 self)
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Abstract. The least common subsumer (lcs) of a set of concept descriptions is the most specific concept description that subsumes all of the concept descriptions in the given set. By computing the lcs, commonalities between concept descriptions can be made explicit. This is an important inference task useful in several applications, including, for instance, the bottomup construction of description logic knowledge bases.
Design Repositories On The Semantic Web With DescriptionLogic Enabled Services
 Proceedings of VLDB Semantic Web and Databases Workshop
, 2003
"... All engineering firms maintain archives of previously designed artifacts, often in the form of databases of computer aided design (CAD) data. Design repositories are an evolution of such databases to include more heterogenous information and to provide enhanced capabilities through the applicatio ..."
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Cited by 6 (0 self)
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All engineering firms maintain archives of previously designed artifacts, often in the form of databases of computer aided design (CAD) data. Design repositories are an evolution of such databases to include more heterogenous information and to provide enhanced capabilities through the application of knowledge representation techniques. This paper introduces ongoing work on applying description logic and the Semantic Web to constructing such design repositories.
Pushing the SONIC border – SONIC 1.0
 Proc. of Fifth International Workshop on FirstOrder Theorem Proving (FTP 2005). Technical Report University of Koblenz, 2005. http://www.unikoblenz.de/fb4/publikationen/gelbereihe/RR132005.pdf. c○2007/TONES – March 31, 2007 55/55 TONESD15 – v.1.1
"... Abstract. This paper reports on extensions of the Description Logics nonstandard inference system Sonic. The recent contributions to the system are twofold. Firstly, Sonic is extended by two new of nonstandard inferences, namely, implementations of the good common subsumer w.r.t. a background ter ..."
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Cited by 4 (3 self)
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Abstract. This paper reports on extensions of the Description Logics nonstandard inference system Sonic. The recent contributions to the system are twofold. Firstly, Sonic is extended by two new of nonstandard inferences, namely, implementations of the good common subsumer w.r.t. a background terminology and a heuristics for computing a minimal rewriting. Secondly, Sonic is available as a plugin for the wellknown ontology editor Protégé [11]. 1
A similarity measure for the ALN description logic
 IN PROCEEDINGS OF CILC 2006  ITALIAN CONFERENCE ON COMPUTATIONAL LOGIC
"... Abstract. This work presents a similarity (and a derived dissimilarity) measure for Description Logics that are the theoretical counterpart of the standard representations for ontological knowledge. The focus is on the definition of a similarity measure for ALN concept descriptions, based both on th ..."
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Cited by 3 (2 self)
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Abstract. This work presents a similarity (and a derived dissimilarity) measure for Description Logics that are the theoretical counterpart of the standard representations for ontological knowledge. The focus is on the definition of a similarity measure for ALN concept descriptions, based both on the syntax and on the semantics of the descriptions elicited from the current state of the world. An extension of the measure is proposed for involving individuals and then for evaluating their (dis)similarity, which makes it suitable for several (inductive) tasks. 1 Assessing the Similarity in Concept Languages In the Semantic Web perspective [3], similarity plays an important role in several tasks, such as classification, clustering, retrieval and knowledge integration. Nevertheless, we are still at an initial phase in the definition of measures for assessing the similarity or the dissimilarity of concepts as described in the standard ontology languages [5]. Various distance measures for concept representations have been proposed in