Study on Key Techniques of Query Expansion Based on Ontology and Its Application

With the population of information technique and Web application, Web information retrieval has became an essential part of work, study and life. As the problems of retrieval increasing, many researches pay more attention on retrieval technique. The study presented in this paper proposes the query expansion technique based on ontology. It uses the rich semantic knowledge of ontology to upgrade the retrieval based on keywords to concepts, and combines it with the specialized engine to improve retrieval effect and efficiency. The paper also takes patent information for example to explain its application at the end.