Ontologies and description logics (original) (raw)
Related papers
Description logics in ontology applications
2005
Description Logics (DLs) are a family of logic based knowledge representation formalisms. Although they have a range of applications (eg, configuration and information integration), they are perhaps best known as the basis for widely used ontology languages such as OWL (now a W3C recommendation). This decision was motivated by a requirement that key inference problems be decidable, and that it should be possible to provide reasoning services to support ontology design and deployment.
Description Logics for Ontologies
Lecture Notes in Computer Science, 2003
Description Logics (DLs) are a family of knowledge representation formalisms designed for the representation of terminological knowledge. A DL knowledge base consists (at least) of a set of concept definitions, namely of those concepts that are relevant for the specific application. Standard inference services provided by DL-based knowledge representation systems include tests whether each defined concept is satisfiable and the computation of the subsumption hierarchy of the defined concepts, i.e., of the specialisation relation between the defined concepts. Besides the well-defined semantics of DLs, these inference services make DLs suitable candidates for ontology languages, which have become of increasing importance due to the amount of information available electronically and the vision of the semantic web. For a variety of DLs, decision procedures, tight complexity bounds, and practical inference algorithms for the corresponding inference problems are known. It is clear that, to be of use as an ontology language, a description logic has to provide adequate expressive power, and we are thus concerned with the well-known trade-off between complexity and expressiveness. After a brief introduction to ontologies, we introduce the basic description logic ALC and describe how DLs can be used as ontology languages. Next, we sketch the relationship between DLs and other formalisms such as first order and modal logic and data base conceptual models. To give a broader view of DLs, some standard expressive means in DLs are mentioned as well as their modal logic counterparts and their effect on the complexity of the inference problems. In Section 3, we give an intuitive explanation of standard reasoning techniques employed for DLs and discuss their respective advantages: tableau-based algorithms turned out to be well-suited for implementations, whereas automata-based algorithms yield elegant upper complexity bounds for Exptime logics. In many cases, first a DL was proven to be in Exptime using automata before a tableau-based algorithm was designed and implemented.
The Description Logic Handbook
2007
Description logics are embodied in several knowledge-based systems and are used to develop various real-life applications. Now in paperback, The Description Logic Handbook provides a thorough account of the subject, covering all aspects of research in this field, namely: theory, implementation, and applications. Its appeal will be broad, ranging from more theoretically oriented readers, to those with more practically oriented interests who need a sound and modern understanding of knowledge representation systems based on description logics. As well as general revision throughout the book, this new edition presents a new chapter on ontology languages for the semantic web, an area of great importance for the future development of the web. In sum, the book will serve as a unique resource for the subject, and can also be used for self-study or as a reference for knowledge representation and artificial intelligence courses.
2008
In this chapter we will introduce description logics, a family of logic-based knowledge representation languages that can be used to represent the terminological knowledge of an application domain in a structured way. We will first review their provenance and history, and show how the field has developed.
Representing ontologies using description logics, description graphs, and rules
2009
Description logics (DLs) are a family of state-of-the-art knowledge representation languages, and their expressive power has been carefully crafted to provide useful knowledge modeling primitives while allowing for practically effective decision procedures for the basic reasoning problems. Recent experience with DLs, however, has shown that their expressivity is often insufficient to accurately describe structured objects—objects whose parts are interconnected in arbitrary, rather than tree-like ways.
Formalisms for representing Ontologies: State of the art survey
2006
Abstract In this document we provide a structured overview of formalism for the representation of ontologies developed in Logic and Artificial Intelligence, and survey the state of the art in methods and techniques for automated reasoning studied in Computational Logic. Since a more general overview of such formalisms has already been reported as part of the deliverable D01 “State of the art survey”, here we concentrate on a wide family of logics, called Description Logics (DLs).
Applications of description logics: State of the art and research challenges
2005
Description Logics (DLs) are a family of class based knowledge representation formalisms characterised by the use of various constructors to build complex classes from simpler ones, and by an emphasis on the provision of sound, complete and (empirically) tractable reasoning services. They have a range of applications, but are mostly widely known as the basis for ontology languages such as OWL.
OWL: a Description Logic Based Ontology
Description Logics (DLs) are a family of class (concept) based knowledge representation formalisms. They are characterised by the use of various constructors to build complex concepts from simpler ones, an emphasis on the decidability of key reasoning tasks, and by the provision of sound, complete and (empirically) tractable reasoning services.