In the Semantic Web, knowledge integration is frequently performed between heterogeneous knowledge bases. Such knowledge integration often requires the schema expressed in one knowledge modelling language be translated into an equivalent schema in another knowledge modelling language. This paper defines how schemas expressed in OWL-DL (the Web Ontology Language using Description Logic) can be t...

OWL has been designed to be a formal language for representing ontologies in the Semantic Web. In short, OWL is the result of combining an expressive Description Logic (DL) with techniques and standards of the Web. DLs have been well studied in the field of knowledge representation over the last decades. As one result, some highly optimized DL reasoners have been implemented, which provide an e...

Description Logics are knowledge representation formalisms that provide, for example, the logical underpinning of the W3C OWL standards. Conjunctive queries, the standard query language in databases, have recently gained significant attention as an expressive formalism for querying Description Logic knowledge bases. Several different techniques for deciding conjunctive query entailment are avai...

This thesis proposes an approach to combine the abilities of Description Logic reasoning with the expressiveness of F-Logic rules. Description Logics (DL) play a key role in ontology modeling for the Semantic Web, most notably as the underlying logic of OWL DL. However, their expressiveness is limited, in particular in conjunction with efficient reasoning. Furthermore, the logic programming par...

This paper presents a tableaux decision procedure for SHOIQ, the DL underlying OWL DL. To the best of our knowledge, this is the first goal-directed decision procedure for SHOIQ.

This paper addresses the challenge of applying Semantic Web technologies like OWL-DL reasoners to XML documents to find implied relationships not stated directly in the documents. The challenge comes because the structure of XML schema often contains implicit assumptions about taxonomy and relationships. This makes it difficult to implement a completely general and automated mechanism to transf...

This paper describes the OWL ontology explorer OntoXpl. It is available as a web server based on the tomcat architecture. Standard HTML browsers can be used to interact with OntoXpl. At least three potential user groups are targeted by OntoXpl’s design: (i) users with a limited background of ontologies and OWL; (ii) ontology developers that are OWL experts; (iii) users interested in understandi...

Several standards are expressed using XML Schema syntax, since the XML is the default standard for data exchange in the Internet. However, several applications need semantic support offered by domain ontologies and semantic Web tools like logic-based reasoners. Thus, there is a strong need for interoperability between XML Schema and OWL. This can be achieved if the XML schema constructs are exp...

In this paper, we present an algorithm that provides natural language (NL) paraphrases for OWL Ontologies on the Semantic Web. Our goal is to ensure both fluency (readability) and accuracy of the output, in terms of preserving the meaning conveyed by its description logic formalism. The approach described is a generic domain-independent one, and is completely automated. We describe details abou...