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"Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality
, 1992
"... Most recent key developments in research on knowledge representation (KR) have been of the more theoretical sort, involving worstcase complexity results, solutions to technical challenge problems, etc. While some of this work has inuenced practice in Arti cial Intelligence, it is rarelyif ever ..."
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Cited by 46 (3 self)
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Most recent key developments in research on knowledge representation (KR) have been of the more theoretical sort, involving worstcase complexity results, solutions to technical challenge problems, etc. While some of this work has inuenced practice in Arti cial Intelligence, it is rarelyif evermade clear what is compromised when the transition is made from relatively abstract theory to the real world. classic is a description logic with an ancestry of extensive theoretical work (tracing back over twenty years to klone), and several novel contributions to KR theory. Basic research on classic paved the way for an implementation that has been used signi cantly in practice, including by users not versed in KR theory. In moving from a pure logic to a practical tool, many compromises and changes of perspective were necessary. We report on this transition and articulate some of the profound inuences practice can have on relatively idealistic theoretical work. We have found that classic has been quite useful in practice, yet still strongly retains most of its original spirit, but much of our thinking and many details had to change along the way.
Matching in Description Logics with Existential Restrictions
 In Proc. of KR2000
, 2000
"... Matching of concepts against patterns is a new inference task in Description Logics, which was originally motivated by applications of the Classic system. Consequently, the work on this problem was until now mostly concerned with sublanguages of the Classic language, which does not allow for existen ..."
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Cited by 23 (15 self)
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Matching of concepts against patterns is a new inference task in Description Logics, which was originally motivated by applications of the Classic system. Consequently, the work on this problem was until now mostly concerned with sublanguages of the Classic language, which does not allow for existential restrictions. This paper extends the existing work on matching in two directions. On the one hand, the question of what are the most &quot;interesting &quot; solutions of matching problems is explored in more detail. On the other hand, for languages with existential restrictions both, the complexity of deciding the solvability of matching problems and the complexity of actually computing sets of &quot;interesting &quot; matchers are determined. The results show that existential restrictions make these computational tasks more complex. Whereas for sublanguages of Classic both problems could be solved in polynomial time, this is no longer possible for languages with existential restrictions.
What's in an Attribute?  Consequences for the Least Common Subsumer
, 2001
"... Functional relationships between objects, called "attributes", are of considerable importance... ..."
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Cited by 13 (3 self)
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Functional relationships between objects, called "attributes", are of considerable importance...
Calculating with Concepts: a Technique for the Development of Business Process Support
, 2001
"... This paper introduces the Calculating with Concepts (CC) technique, which has been developed to improve the precision of UML class diagrams and allows the formal reasoning based on these diagrams. This paper aims at showing the industrial benefits of using such a formal and rigorous approach to reas ..."
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Cited by 11 (2 self)
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This paper introduces the Calculating with Concepts (CC) technique, which has been developed to improve the precision of UML class diagrams and allows the formal reasoning based on these diagrams. This paper aims at showing the industrial benefits of using such a formal and rigorous approach to reason about business processes and software applications in the early phases of the software development process. The paper discusses how the CC technique can be used in the specification of business processes and in the development of their supporting software applications or tools. This paper also illustrates the use of the technique with a realistic case study on tool integration.
What's not in a name: Some Properties of a Purely Structural Approach to Integrating DL Terminologies.
 Proceedings of the International Workshop on Description Logics (DL2000), number 33 in CEURWS
, 2000
"... One approach to integrating knowledge bases is based on finding assertions that relate the expressions in the constituent terminologies. For knowledge bases with many terms this task requires computer support. We set up a formal framework for merging Description Logic TBoxes, and then explore the li ..."
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Cited by 10 (3 self)
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One approach to integrating knowledge bases is based on finding assertions that relate the expressions in the constituent terminologies. For knowledge bases with many terms this task requires computer support. We set up a formal framework for merging Description Logic TBoxes, and then explore the limits of a purely structural approach to the problem of finding interrelationships between knowledge bases. Some theoretical notions are empirically examined in a real medical ontology (galen).
Matching Concept Descriptions with Existential Restrictions
, 1999
"... Matching of concepts with variables (concept patterns) is a relatively new operation that has been introduced in the context of description logics, originally to help filter out unimportant aspects of large concepts appearing in industrialstrength knowledge bases. Previous work has concentrated ..."
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Cited by 4 (2 self)
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Matching of concepts with variables (concept patterns) is a relatively new operation that has been introduced in the context of description logics, originally to help filter out unimportant aspects of large concepts appearing in industrialstrength knowledge bases. Previous work has concentrated on (sub)languages of CLASSIC, which in particular do not allow for existential restrictions. In this work, we present sound and complete decision algorithms for the solvability of matching problems and for computing sets of matchers for matching problems in description logics with existential restrictions.
FP67603 – Thinking ONtolgiES (TONES) WP7 – Experimentation And Testing of the Common Logical Framework
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Architecture of Distributed Systems Anaxagoras Procesarchitecten B.V. Supervision: Supervision:
, 2001
"... iSummary This thesis describes how the Calculating with Concepts technique, a formal conceptual modelling technique, can be used in the eld of Process Architecture. First we show that the Calculating with Concepts technique can be used to enhance existing design methodologies. We show that the Calcu ..."
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iSummary This thesis describes how the Calculating with Concepts technique, a formal conceptual modelling technique, can be used in the eld of Process Architecture. First we show that the Calculating with Concepts technique can be used to enhance existing design methodologies. We show that the Calculating with Concepts technique can be used to derive formal specications from conceptual models. The resulting formal specications contain more information than the conceptual models from which they are derived. This is achieved by using a technique called cycle chasing to nd information regarding interrelation dependencies and making it explicit in the Calculating with Concepts notation. We also show that the interpretation of the specications is more clear than the interpretation of the conceptual models from which they are derived, because the specications have a formal basis. Second we show that the Calculating with Concepts technique can be used to facilitate design discussions, by reasoning with Calculating with Concepts
Matching with respect to general concept inclusions in the Description Logic EL
"... Matching concept descriptions against concept patterns was introduced as a new inference task in Description Logics (DLs) almost 20 years ago, motivated by applications in the Classic system. For the DL EL, it was shown in 2000 that the matching problem is NPcomplete. It then took almost 10 years b ..."
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Matching concept descriptions against concept patterns was introduced as a new inference task in Description Logics (DLs) almost 20 years ago, motivated by applications in the Classic system. For the DL EL, it was shown in 2000 that the matching problem is NPcomplete. It then took almost 10 years before this NPcompleteness result could be extended from matching to unification in EL. The next big challenge was then to further extend these results from matching and unification without a TBox to matching and unification w.r.t. a general TBox, i.e., a finite set of general concept inclusions. For unification, we could show some partial results for general TBoxes that satisfy a certain restriction on cyclic dependencies between concepts, but the general case is still open. For matching, we solve the general case in this paper: we show that matching in EL w.r.t. general TBoxes is NPcomplete by introducing a goaloriented matching algorithm that uses nondeterministic rules to transform a given matching problem