The Semantic Web is an extension of the current web, where information would have precisely defined meaning, based on formal semantics, and structured using a knowledge representational language. The current W3C standard for representing knowledge is the Web Ontology Language (OWL). OWL is based on Description Logics which is a popular knowledge representation formalism. Although, DLs are quire...

This is the tenth in a series of articles on ontology-based approaches to modeling. The main focus is on popular ontology languages proposed for the Semantic Web, such as the Resource Description Framework (RDF), RDF Schema (RDFS), and the Web Ontology Language (OWL). OWL is based on description logic. A later series of articles will explore other logic-based languages such as datalog. The firs...

This is the fourteenth in a series of articles on ontology-based approaches to modeling. The main focus is on popular ontology languages proposed for the Semantic Web, such as the Resource Description Framework (RDF), RDF Schema (RDFS), and the Web Ontology Language (OWL). The first article [3] introduced ontologies and the Semantic Web, and covered basic concepts in the Resource Description Fr...

We propose a description-logic style extension of OWL DL, which includes DL-safe variable SWRL and seamlessly integrates datalog rules. Our language also sports a tractable fragment, which we call ELP 2, covering OWL EL, OWL RL, most of OWL QL, and variable restricted datalog.

Being able to extend an OWL ontology with some form of rules is a feature that many ontology developers consider as very important. Nevertheless, working with rules in practice can be difficult since the tool support is not as good as for handling ontologies without rules. Furthermore, the existing rule syntaxes are not very well aligned with the new OWL 2 standard. We propose, therefore, an ex...

This paper details the use of OWL FA Toolkit for verifying and validating multi-layered (meta-) modelling using ontologies described in OWL FA. We will show how OWL FA and its reasoner (OWL FA Toolkit) could benefit software modellers on leveraging the software development life cycle through a practical use case.

A variety of tools for visualizing, editing, validating, and documenting OWL ontologies have been developed in the last couple of years. The OWL coverage and conformance of these tools usually needs to be tested during development for evaluation and comparison purposes. However, in particular for the testing of special OWL concepts and concept combinations, it can be tedious to find suitable on...

Our knowledge of the biological mechanisms underlying complex human disease is largely incomplete. While Semantic Web technologies, such as the Web Ontology Language (OWL), provide powerful techniques for representing existing knowledge, well-established OWL reasoners are unable to account for missing or uncertain knowledge. The application of inductive inference methods, like machine learning ...

Ontologies are expected to play an important role in many application domains, as well as in software engineering in general. One problem with using ontologies within software engineering is that while UML, a widely used standard for specifying and constructing the models for a software-intensive system, has a four-layer metamodelling architecture, the standard Web Ontology Language (OWL) does ...

The purpose of this paper is to provide an introduction to the OWL Web ontology language, a survey focused on the current state of the art in OWL inferencing capabilities, and a historical perspective on procedural attachments. The perspective is aligned with current OWL research. Several limitations of the OWL language and proposed extensions to overcome these limitations are discussed. A fram...