Research And Implement Of Knowledge Retrieval System Based On Ontology

With the rapid development of the ecnomicity, enterprise faces fiercer competitive environment. In order to promote there own responsive abilities and competitive power, erterprise need to strengthen their management. In the enterprise of the various factors, more and more people attach the importance of companies'knowledge; Business documents play more and more important position in the enterprise. Business documents are the essence of the whole enterprise knowledge, accumulation, mutual learning between enterprises, exchanges play a decisive role. However, it is the face of corporate documents chaotic confusion, we do not know how to access the information they want. Therefore information retrieval technology is particularly important; it is the only way to improve competitiveness of business. But the retrieval technology are largely based on string matching keyword search technology, and the lack of semantic retrieval technology such reasoning ability of the user's request did not provide for semantic guidance, resulting in the misuse of information seized, missed. So how to improve the quality of information retrieval become information retrieval, data mining and knowledge management research in the field of important issues.Ontology as the new concept to describe the semantic hierarchy of knowledge has been widely used in different fields.The information retrieval methods combined with ontology can not only emphasize the advantages of knowledge-based retrieval But also deal with the relationships between the various concepts. Though the research of ontology is just at the beginning, the application of ontology in information retrieval and semantic web will be the focus in this field.The proposal and development of knowledge retrieval based on ontology is a new inspiration. On the base of summarizing then current condition of information retrieval studies, this essay concertrates on ontology and 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 enterprise document knowledge retrieval system as object, to which the semantic search is applied. By building the domain ontology and building an experimental retrieval system, it's to prove the qualitative increase of the precision ratio and recall ratio of retrieva method and tool build on ontology .