Vertical Search Based On Semantic Query Expansion

With the rapid development of Internet technology, the web information also accordingly grows at a very high speed. It becomes a hot reaseach topic that how to search the useful information user needed from a vast amounts of information. Search engine as the Internet information retrieval technology is widely used. As a information retrieval technology in the search area vertical search extends to a large extent to improve the performance of the search elements. However, that the traditional keyword-based search engine can not provide organization, understanding and treatment about semantic-level information on the Internet, also can not guarantee that search precision.Query expansion as a way to effectively improve the retrieval method has been widely used. With the semantic web and ontology development, which enables information organized in a structured form and described the semantic information. On this basis this article proposed a ontology-based semantic query expansion method, it can effectively solve many errors about the semantic understanding which has been brougth by the traditional way of query expansion, and established a vertical search engine model based on this article concept. It makes semantic query expansion to the keyworks which are submited by user through the domain ontology, so as to improve query recall rate and precision rate.The main contents of this paper are organized as follows:The second chapter introduces the ontology concepts and techniques, and establishs a piece of ontology about the computer science and then conducted a summary of the semantic web discussion; third chapter describes development of the query expansion technology and a wide range of semantic query expansion methods which are popular; fourth chapter elaborates a semantic ontology-based query expansion method, firstly proposed a method about concept similarity calculation within ontology, make the concept expansion by using of concept similarity, secondly proposed a method about text tagging based on window model, expands query according to the document-concept index; ChapterⅤIn this paper, based on the semantic query expansion methods, this paper established a vertical search engine concept model, and outlines the implementation details. ChapterⅥdescribes the experimental system in this paper, and analyze the experimental results.