The term “Federated Databases” refers to the data integration of distributed, autonomous and heterogeneous databases. However, a federation can also include information systems, not only databases. When integrating data, several issues must be addressed. Here, we focus on the problem…

Data integration is the process of unifying data sharing some common semantics but are originated from unrelated sources. In our work we consider these sources are autonomous, heterogeneous and they are physically distributed. These three characteristics make the integration task…

Semantic Web is an extension of the current web in which data contained in the web documents are machine-understandable.
On the other hand, Web Services provide a new model of the web in which sites exchange dynamic information on demand.

During the last years a lot of projects and lines of research have emerged from different proposals trying to find the best way to reach data integration. Two powerful techniques have appeared separately – ontology and contextual information – in…

Effective document retrieval using domain knowledge and semantics is one of the major challenges in Information Retrieval. Over the last years, there has been a growing interest in ontologies as an artifact for human knowledge representation and a critical component…