Domain ontology based semantic search for efficient information retrieval through automatic query expansion

To achieve semantic search, a search engine is needed which can interpret the meaning of a user´s query and the relations among the concepts that a document contains with respect to a particular domain. We are presenting the skeleton of such a system based on ontology. In this system, a user enters a query from which the meaningful concepts are extracted; using these concepts and domain ontology, query expansion is performed. For all the terms (expanded and initial query terms), SPARQL query is built and then it is fired on the knowledge base that finds appropriate RDF triples in knowledge Base. Web documents relevant to the requested concepts and individuals specified in these triples are then retrieved. Finally, the retrieved documents are ranked according to their relevance to the user´s query and then are sent to the user. If a user wants to find specific information; can search with another module of our system that works without query expansion. The approach of query expansion makes use of query concepts as well as synonyms of these concepts and the new terms relate with the original query terms within a threshold.