Ontology mapping and SPARQL rewriting for querying federated RDF data sourcesOntology mapping and SPARQL rewriting for querying federated RDF data sources Πλήρης Δημοσίευση σε Συνέδριο Conference Full Paper 2015-10-042010enThe web of data consists of distributed, diverse (in terms of schema adopted), and large RDF datasets. In this paper we present a SPARQL query rewriting method which can be used to achieve interoperability in semantic information retrieval and/or knowledge discovery processes over interconnected RDF data sources. Formal mappings between dierent overlapping ontologies are exploited in order to rewrite initial user SPARQL queries, so that they can be evaluated over dierent RDF data sources on dierent sites. The proposed environment is utilized by an ontology-based mediator system, which we have developed in order to provide data integration within the Semantic Web environment.http://creativecommons.org/licenses/by/4.0/1108-1117In the Proceedings of the 9th International Conference on Ontologies, DataBases, and Applications of Semantics (ODBASEpaper350.pdfChania [Greece]Library of TUC2015-10-04application/pdf401.8 kBfree Christodoulakis Stavros Χριστοδουλακης Σταυρος Konstantinos Makris Gioldasis Nektarios Nikos Bikaki Springer Verlag Ontology Mapping Mode