Understanding the logical meaning of any description logic or similar formalism is difficult for most people, and OWL-DL is no exception. This paper presents the most common difficulties encountered by newcomers to the language, that have been observed during the course of more than a dozen workshops, tutorials and modules about OWL-DL and it’s predecessor languages. It emphasises understanding...

The Web Ontology Language (OWL) is the most expressive standard language for modeling ontologies on the Semantic Web. In this chapter, we present the temporal OWL (tOWL) language: a temporal extension of the OWL DL language. tOWL is based on three layers added on top of OWL DL. The first layer is the Concrete Domains layer, which allows the representation of restrictions using concrete domain b...

Web Ontology Language (OWL) [5] can be seen as an extension of Resource Description Framework (RDF). The primary exchange syntax for OWL is RDF/XML, and every OWL ontology can be represented as an RDF graph. But there is no standard query language specifically for OWL ontologies. The most commonly used Semantic Web query language is SPARQL [7], which is intended to be used for RDF. Roughly spea...

The National Cancer Institute's (NCI) Thesaurus is a biomedical reference ontology. The NCI Thesaurus is represented using Description Logic, more specifically Ontylog, a Description logic implemented by Apelon, Inc. We are exploring the use of the DL species of the Web Ontology Language (OWL DL)-a W3C recommended standard for ontology representation-instead of Ontylog for representing the NCI ...

Business contracts are the key governing mechanism for inter-organizational collaboration and they are increasingly taking a central role in e-commerce, e-business and extended enterprise governance related to key process integration, exchange of knowledge and information and as drivers for performance. This research is motivated by the critical problem of stark incompatibility between the cont...

The recent OWL 2 W3C recommendation includes the lightweight ontology language OWL EL which is semantically based on an extension of the EL description logic (DL). It is widely assumed that inferencing in OWL EL is possible in polynomial time, but it is not obvious how to extend existing reasoning procedures for EL accordingly. We set out to close this gap by developing inferencing methods for ...

Understanding the logical meaning of any description logic or similar formalism is difficult for most people, and OWL-DL is no exception. This paper presents the most common difficulties encountered by newcomers to the language, that have been observed during the course of more than a dozen workshops, tutorials and modules about OWL-DL and it’s predecessor languages. It emphasises understanding...

With the expanse of internet, web programmers have wide choice of web services available to them. A need arises for automatic discovery of required web services and construction of an appropriate sequence of invocation thereof. In this paper, we present a framework for automation of this task based on currently emerging technologies such as ontological knowledge bases, OWL, OWL-S, WSDL, Descrip...

OWL is a very expressive language, but some user obviously struggle to formulate what they want to say. Now, some of these users may find it easier to write down a SWRL rule instead of an OWL axiom. Hence, we present a rule editor plug-in for Protégé that brings something different to rule and OWL integration. We part from the two usual approaches: (i) use it as is with say, Hoolet, knowing tha...

Ontologies are nowadays one of the most prominent formalisms used in the area of Semantic Web for knowledge representation. Several efforts have been made by the W3C in order to define OWL (Web Ontology Language) and by developers in order to develop reasoners able to deal with ontologies defined by means of OWL. Unfortunately, the goals of the working groups for standard languages definition r...