G. Meditskos, N. Bassiliades, “O-DEVICE: An Object-Oriented Knowledge Base System for OWL Ontologies”, Proc. 4th Hellenic Conference on Artificial Intelligence (SETN-06), G. Antoniou, G. Potamias, D. Plexousakis, C. Spyropoulos (Ed.), Springer-Verlag, LNAI 3955, pp. 256-266, Heraklion, Crete, 18-20 May, 2006.
Rule systems are a key component for the next step of evolution of the Semantic Web, allowing the development of declarative systems on top of ontologies. This paper reports on the implementation of such a system, called O-DEVICE, for reasoning over OWL documents. O-DEVICE exploits the rule language of the CLIPS production rule system and transforms OWL ontologies into an object-oriented schema of COOL. During the transformation procedure, OWL classes are mapped to COOL classes, OWL properties to class slots and OWL instances to COOL objects. The purpose of this transformation is two-fold: a) to exploit the advantages of the object-oriented representation and ac-cess all the properties of instances in one step, since properties are encapsulated inside resource objects; b) to be able to use a deductive object-oriented rule language for reasoning about OWL data, which operates over the object-oriented schema of CLIPS. The deductive rules are compiled into CLIPS pro-duction rules. The semantics of OWL are partly handled by the OWL transfor-mation procedure and partly by the rule compilation procedure.