A Model Study Of Ontology-based Semantic Information Search

General information retrieval system sxposed some obvious defects, such as low retrievaleffectiveness and Inappropriate answers. A very important aspect of the causes of this problem lies inthe information retrieval system can not understand the semantics of the user, which makes it difficult tomeet the user demands. To solve this problem, the concept of semantic information search has beenproposed.Since it proposed, the semantic information search is becoming a hot area of informationretrieval research. However, at this stage, the semantic search research is faced with two problems: First,did not find an effective means of parsing user semantic and locating the user demand. Second, has notformed a full-fledged semantic search model. These two problems has been a serious impediment to thein-depth development of the semantic information search, so, they are the key issues in this area need tobe resolved.Based on the situational theory, this study combinated the contextual factors as an effective meansof narrowing the user semantic openness and positioning the means of user needs. The ontology hasbeen used to exchange the abstract contextural factors into some specific various which can be read anduse by information retrival systems. Based on these various, a semantic search model has been built. Totest the model, an experimental system was developed which has been proved has a greaterimprovement by an experiment.Three contributions have been made:The first is proposed a context-orinted semantic search frame. Three context variables affecting theinformation retrieval process has been selected into the framework from many context factors. They areuser knowledge structure, task and information environment. Further more, the method of expressingthe context variables was proposed.The second is made a technical program to use the semantic search framework in semanticinformation search. Based on the semantic search framework, a context-orinted semantic search modelwas proposed. In this technical solution, the task-aware algorithm, the tasks expression algorithm andthe results sorting algorithm are discussed and the ontology structure compatible with these algorithmsis expounded.The third is developed a pomology semantic search system. This system has been proved has agreater improvement in the search results appropriate level, retrieval performance and the degree ofintelligence by a comparison test with Baidu search engine. So, the feasibility of the semantic searchmodel has been tested.