A Federated System is a collection of independent, cooperative, possibly heterogeneous and autonomous computer systems (usually database systems) which allows sharing all or some of its data. A Service-oriented Architecture is an application architecture whose functionalities are defined as independent…

Ontologies serve as a mean to establish a conceptually concise basis for communicating knowledge for many purposes. Within the information integration area, ontologies are useful to solve heterogeneity problems. They provide a set of knowledge terms, including the vocabulary, the…