Research On Semantic Intelligent Information Retrieval System Based On The Ontology

With the rapid development of Internet, we can live in a rich knowledge pool. However, to such rich information pool, we can't find real information which we need. Throughout information on Internet, it has follow features: (1) great variety of contents, and rich information; (2) various manifestations of information; (3) dynamic change, and significant time-effectiveness; (4) orderliness on local information organization and chaos on whole organization. These features make Internet emerge"Information Explosion". The searching way of traditional information retrieval systems is mainly based on keywords. The advantages of such retrieval method can provide users a convenient way to retrieve required information. Though such way can receive a high recall, it has a lower precision for the price, which makes users spend more time on excluding irrelevant information. In such an explosive day,it is essential to retrieve more precise information with less spending. Thus, the requirements to improve precision requirement become intense. To meet such requirements, information retrieval must be improved on knowledge level, and organize and describe information on semantic level to design an intelligent information retrieval system.Ontology, as a concept modeling tool to describe information system on semantic and knowledge level, has aroused great attention around the world after put forward. In addition, ontology is widely used in many fields on computer science, such as Knowledge Engineering, Digital Library, Software Reuse, Information Retrieval, Handling heterogeneous information on web and Semantic Web, etc. After introducing ontology theories into information retrieval system, we can realize the semantic retrieval, which can reach a qualitative leap on recall and precision. Semantic query technique based on ontology is receiving an extensive attention and application.Firstly, this paper elaborates ontology relevant theories, OWL, and the effects of ontology on semantic retrieval system. Secondly, the current existing methods of constructing ontology are introduced. Thirdly, the advantages of existed ontology construction methods are utilized; adaptability and strong applicability domain ontology construction method is put forward; and medical domain ontology is constructed based on this method. Finally, the effects of semantic web application system development tool-Jena which are developed by HP are studied in the paper.To solve disadvantages of traditional information retrieval system, this paper puts forward a framework of intelligent retrieval system based on ontology, and designs a semantic intelligent retrieval system based on medical ontology made on Chapter3. The system reasons ontology through Jena, which can make retrieved information having semantic function. Such retrieved information can be further persistent through Database. In the process of inquiring information through database, this paper takes Lucene toolkit, which is a text information retrieval tool based on Java. Firstly, tables are created index in database using Lucene. Then, queries to persisted semantic information are further expanded. Furthermore, the performance of this system is examined through system experiment. Experiment results show that this system not only improve precision ratio and recall ratio, but also realize semantic query expansion.Currently, there have been many scholars devoted to research semantic intelligent retrieval system. This paper, after referring to the existing research, puts ontology reasoning and database queries together in order to find new thoughts on semantic intelligent information retrieval system based on ontology.