关键词: 林业叙词表, 语义检索, 相似度计算, 查询扩展, 网页抓取

Abstract: With the speedy development of the Internet, keyword-based retrieval method has failed to meet the needs of people. The semantic relationship within the thesaurus can improve recall ratio and precision ratio. If the thesaurus is introduced into current network information retrieval tool, the search technology would be definitely improved with the aid of rich semantic relationship of the thesaurus. This paper proposes an idea of calculating the similarity based on the relationship among the terms in the thesaurus. Utilizing query extension, this paper designs a semantic model with thesaurus for forestry information retrieval (SMTFIR). Finally, this paper compares SMTFIR, Baidu and the method used in agricultural thesaurus with two category realms in forestry thesaurus. The?results show that SMTFIR can improve keyword-based retrieval method more effectively using thesaurus. In addition, SMTFIR is also suitable to other domains and provides a new thought for applying thesaurus in network information system.

Key words: forestry thesaurus, semantic retrieval, similarity computation, query extension, webpage grabbing