A Graph Theoretical Foundation for Integrating RDF Ontologies

Abstract

RDF ontologies are rapidly increasing in number. We study the problem of integrating two RDF ontologies under a given set H of Horn clauses that specify semantic relationships be-tween terms in the ontology, as well as under a given set of negative constraints. We formally dene the notion of a wit-ness to the integrability of two RDF ontologies under such constraints. A witness represents a way of integrating the ontologies together. We dene a minimal witnesses and provide the polynomial CROW (Computing RDF Ontology Witness) algorithm to nd a witness. We report on the per-formance of CROW both on DAML, SchemaWeb and Onto-Broker ontologies as well as on synthetically generated data. The experiments show that CROW works very well on real-life ontologies and scales to massive ontologies.