System of Mediation based on Ontology to Solve the Semantic Heterogeneity between Information Systems

The Semantic Web is a new vision of the Web, where resources are described by meta-data, using the conceptual vocabulary provided by the ontology, which allow software agents to better assist users in their various resources access Web. E-learning is considered as one of the areas in which the Semantic Web can make real progress that is looking for information or reuse of learning resources, even in customizing monitoring training. In this article, we focus on the semantic heterogeneity between information systems and we propose a mediation system based on ontologies, to allow the integration of heterogeneous sources. Ontologies allow systems to use a terminology consensus. We use the mapping between different ontologies. This mapping will be used in the process of query rewriting. Ontologies and the mapping are described with OWL. we present our proposed method for translating SPARQL queries in XQuery queries. This method is based on the XML-to-ontology mapping.