Ontology alignment based support for searching LOD-datasets using SPARQL query

Abstract

The Linked Open Data (LOD) cloud is rapidly becoming the largest interconnected source of structured data on the web. Due to distributed nature of LOD and a growing number of ontologies and vocabularies used in LOD datasets,querying over multiple datasets and retrieving data from LOD-cloud remains a challenging task. The data on the LOD-cloud is stored in Resource Description Format(RDF) and SPARQL is the standard language for searching over RDF data. Different systems like LOQUS[1], ALOQUS[2] has been designed to formulate SPARQL queries which can obtain data from this LOD-cloud effectively and efficiently. Our work focusses on implementing a system like LOQUS,ALOQUS which uses SPARQL query to obtain data from the different LOD-datasets. But before querying on the datasets, mapping of the dataset specific ontologies with Upper Level Ontology is required, for formulating the SPARQL queries. In our work, we demonstrate ""Mapping Approach"" that is used for implementing our system, how two ontologies are mapped, how sparql queries are created using these mappings and how results are obtained after executing these queries.