Research Of Semantic Retrieval Base On Ontology

Information retrieval technology is particularly critical when processing the explosively increased information resource. It is now an indispensable function of many online systems. However, based on string matching, the keywords retrieval technology is inadequate of processing polysemous words, synonyms, hypernyms, and hyponyms etc., which usually fails to meet clients'demands.A case in point is the present medical information retrieval system. Hoping to acquire the information of certain symptoms, users commonly end up with irrelevant or missing information. Therefore, to create a new efficient retrieval technology is now the focus of studies all over the world.The proposal and development of semantic web is a new inspiration. Semantic retrieval relates to a number of concepts and objects, such as ontology, controlled word list, and semantic web etc. As Semantic retrieval includes many technologies, it is impossible to cover them all in this essay. Firstly, On the base of summarizing the current condition of semantic retrieval studies, this essay concentrates on studying two critical factors: ontology and Web Ontology Language (OWL), while stressing on the connotation and extension of ontology, as well as its function in the semantic retrieval system. Besides, the essay elaborates the structure and grammar of OWL. Further more, it also demonstrates the functions of the semantic-web-developing software—Jena which was developed by HP and web ontology language- SPARQL in current semantic retrieval system. It chooses medical information retrieval system as object, to which the semantic search is applied. By inputting certain medical knowledge to the computer and building an experimental retrieval system, it's to prove the qualitative increase of the precision ratio and recall ratio of the retrieval method and tool built on Ontology.Studying information retrieval and semantic web and relevant theories, methods and technologies, the purpose of the essay is the realization of the semantic retrieval system.