Research On Ontology-based Information Retrieval System

Most of the information retrieval systems are based on mechanical retrieval technique in the syntax layer. The system may miss some information that users really want and return some information that users don't want. In essentially, Ontology is the description of the relations between objective existing concepts, so the Ontology-based information retrieval system provides semantic retrieval which makes up for the flaw of the traditional keywords-based information retrieval system. It is better at recall and precision of the retrieval result.Firstly, the paper gives some analysis to actuality of information retrieval, puts forward the primary issue of study on ontology-based information retrieval system. Then based on expounding the theory of ontology and information retrieval, an Ontology-based information retrieval model and system framework are proposed. And the function and retrieval process are expounded in detail. In the model, semantic index terms can be acquired by ontology. The logical views of documents and user's information needs, generated in terms of these semantic index terms, can represent documents and user's information needs well. So the performance of information retrieval can be improved effectively.Secondly, the paper makes a deeply research on the key technologies of system, including ontology constructing method, ontology-based query pretreatment technology and semantic processing technology. A structural method of constructing ontology is proposed as the theoretic basis of system.Finally, the paper provides the steps of experiment, designs insurance Ontology-based information retrieval system and uses the example to explain Ontology modeling.