Contextualized knowledge repositories for the Semantic Web

We propose Contextualized Knowledge Repository (CKR): an adaptation of the well studied theories of context for the Semantic Web. A CKR is composed of a set of OWL 2 knowledge bases, which are embedded in a context by a set of qualifying attributes (time, space, topic, etc.) specifying the boundaries within which the knowledge base is assumed to be true. Contexts of a CKR are organized by a hierarchical coverage relation, which enables an effective representation of knowledge and a flexible method for its reuse between the contexts. The paper defines the syntax and the semantics of CKR; shows that concept satisfiability and subsumption are decidable with the complexity upper bound of 2NEXPTIME, and it also provides a sound and complete natural deduction calculus that serves to characterize the propagation of knowledge between contexts. (C) 2011 Elsevier B. V. All rights reserved.