Research Of Semantic Information Retrieval Based On Ontology Technology

With the the continuous development of network and information technology, the amount of information on the Internet is booming and the Internet has become the priority choice for information access and a tool closely related to the people's daily life. But it also has the inverse side of effect. Specifically, these development and increments are accompanied by the heterogeneousness of data type and data schema which bring out big challenge to information organization and information retrieval. How to find the valuable information which is needed to users among a tremendous amount of information on the Internet has become a very important problem. The gradually development of information retrieval technology make it possible to tackle this problem.Ontology is a semantic web technology which can be used to clearly describe the concepts and the relationship between concepts of real world theoreticaaly. Ontology-based retrieval system can provide the users search results without ambiguity, which can make up for the shortage of the traditional key words retrieval system. It can guarantee the better recall factor and precision factor of the information retrieval system when scaling ontology-based semantic information retrieval technology. By analyzing the existing technologies in digital libraries and focusing on semantic search of literature resource, this paper proposes semantic information retrieval based on ontology metadata and implements semantic description of literature resources and the semantic search.In this paper, firstly, the purpose and significance of the subject are stated,and the current research based on the ontology of the information retrieval research situation on the ontology and information retrieval of ontology both abroad and at home is analyzed.Secondly, from such respects as the semantic reasoning technology, the improvement of semantic similarity based on ontology and the calculation method of the relativity, searching expansion skill, which is needed for constructing semantic retrieval system based onontology is deeply studied.Thirdly, based on the above theoretical research,the dissertation puts forward research paper search model based on ontology,and sets up a preliminary testing ontology based on computer network papers. Besides, this paper proposes a semantic search algorithm based on SPARQL which uses semantic extended rules of subject concepts to improve search performances, and through the search function testing,the using typical cases to indicate that the technical plan of this paper is effective and fessible.