Ontologies have been used for formal representation of knowledge for many years now. One possible knowledge representation language for ontologies is the OWL 2 Web Ontology Language, informally OWL 2. The OWL specification includes the definition of variants of OWL, with different levels of expressiveness. OWL DL and OWL Lite are based on Description Logics, for which sound and complete reasone...

OWL-DL is a World Wide Web Consortium standard for representing ontologies on the Semantic Web. It can be seen as a syntactic variant of the Description Logic SHOIN (D), with an OWL-DL ontology corresponding to a SHOIN (D) knowledge base. The very recent accomplishment of a decision procedure for SHOIN (D) poses the challenge of turning the decision procedure into a practical implementation. In...

We report on a recent advance in integrating Rules and OWL. We discuss a recent proposal, known as nominal schemas, which realizes a seamless integration of Datalog rules into the description logic SROIQ which underlies OWL 2 DL. We present extensions of the standardized OWL syntaxes to incorporate nominal schemas, reasoning algorithms, and a first naive implementation. And we argue why this ap...

In this paper, we present two translations of the Web Service Policy Framework (WS-Policy) into OWL-DL. First, we provide an overview of existing web policy languages and a general idea of their expressivity. Then we provide a quick introduction to WS-Policy and we argue the benefits of using OWL and RDF to express web service policies. Lastly, we provide two translations from WS-Policy to OWL,...

The semantics of OWL-DL and its subclasses are based on the classical semantics of first-order logic, in which the interpretation domain may be an infinite set. This constitutes a serious expressive limitation for such ontology languages, since, in many real application scenarios for the Semantic Web, the domain of interest is actually finite, although the exact cardinality of the domain is unk...

This paper introduces a visual, UML-based notation for OWL ontologies. We provide a standard MOF2 compliant metamodel which captures the language primitives offered by OWL DL. Similarly, we invent a UML profile, which allows to visually model OWL ontologies in a notation that is close to the UML notation. This allows to develop ontologies using UML tools. Throughout the paper, the significant d...

We present a transformation scheme that mediates between description logics (DL) or RDF-encoded ontologies and type hierarchies in feature logics (FL). The DL-to-FL direction is illustrated by an implemented offline procedure that maps ontologies with large, dynamically maintained instance data to named entity (NE) and information extraction (IE) resources encoded in typed feature structures. T...

We study the problem of updates for TBoxes represented in Description Logics of the DL-Lite family. DL-Lite is at the basis of OWL 2 QL, one of the tractable fragments of OWL 2, the recently proposed revision of the Web Ontology Language. In this paper, we address for the first time the problem of updating TBoxes. We propose some principles that TBox updates should respect. We review known mode...

In order to extract the full potential from Internet-wide content sharing and reuse, the underlying copyright issues must be taken into account. The novel requirements are not satisfied by traditional Digital Rights Management. Open licensing initiatives seem more appropriate, but they lack the required computerised support. Our proposal facilitates interoperation while providing a rich framewo...

We introduce ELP as a decidable fragment of the Semantic Web Rule Language (SWRL) that admits reasoning in polynomial time. ELP is based on the tractable description logic EL, and encompasses an extended notion of the recently proposed DL rules for that logic. Thus ELP extends EL with a number of features introduced by the forthcoming OWL 2, such as disjoint roles, local reflexivity, certain ra...