The Research And Realization Of Text Content Relevance Based On Ontology

In Internet era, user can easily get abundant information, but some information is not related to user's needs. Therefore, it is inevitable to search for new retrieval model to improve the relevance and help people overcome the problem of information overloading. Ontology is a very important technology for semantic Web, it is research hotspot in recent years, and it has concept hierarchy structure and supports logical reasoning. By modeling domain knowledge, it can conveys the semantic knowledge that machine easily understand and achieve content-based retrieval. Therefore, the application of ontology is bound to have a greater positive impact on information retrieval.Through studying lots of related works on Ontology and relevance, this paper combines the two technologies and designs a semantic expansion algorithm base on domain ontology. The aim of the algorithm is to expand query words which user has input and improve the recall and precision ratio. The paper also sorts the query results by multiple factors weighted sorting algorithm and greatly improved the relevance between query words and retrieval results.Base on the semantic expansion algorithm's presentation, an information retrieval system is designed and built with Java language on Eclipse platform. It consists of six parts. They are user interface, query processing module, ontology processing module, Internet resources preprocessing module, search module and query results processing module. Experiments show that the results are accurate with the six modules working cooperatively.This paper through expand initial query words in Ontology knowledge database and use multiple factors weighted sorting algorithm to improve recall ratio and precision ratio of the search system. Demonstrated information retrieval system which performance has greatly improved by semantic expansion and relevance sorting, it is provides powerful reference for building intelligent information retrieval system.