Automatic Partitioning of OWL ontologies using e-connections
Bernardo Cuenca Grau, Bijan Parsia, Evren Sirin, Aditya Kalyanpur · 2005
On the Semantic Web, the ability to combine, integrate and reuse ontologies is crucial. The Web Ontology Language (OWL) defines the owl:imports construct, which allows to include by reference all the axioms contained in another knowledge base (KB) on the Web. This certainly provides some syntactic modularity, but not a logical modularity. We have proposed [3] E-Connections as a suitable formalism for combining KBs and for achieving modular ontology development on the Web. E-Connections are KR languages defined as a combination of other logical formalisms. They were originally introduced in [4] mostly as a way to go beyond the expressivity of each of the component logics, while preserving the decidability of the reasoning services in the combination. We have found that E-Connections can help process, evolve, reuse, and understand OWL ontologies. In this paper, we address the problem of automatically transforming an OWL KB O into a E-Connection Σ in such a way that each of the relevant sub-domains modeled in O is represented in a different component of Σ. We present a formal definition and investigation of different variants of the problem, a polynomial solution for some of them, an optimized implementation and some promising empirical results. We have found that in some large KBs, partitioning to an E-Connection provides modularity benefits. In particular, if a KB can be partitioned, it typically contains several “free standing ” components, that is, sub-KBs which do not “use ” information from any other components. These KBs can be easily reused and evolved without reference to the rest of the E-Connection. We believe that the factoring out of such independent parts of the original KB alone justifies partitioning for many applications.