《模糊数学在信息检索中的应用》-毕业论文.doc

模糊数学在信息检索中的应用 摘 要：本文从模糊集出发，以信息检索为应用背景，逐步引入模糊数学理论，并以提高信息检索的准确率和检索效率为目的，提出以下思想方法： （1）为了提高检索准确率，根据模糊集理论，提出了基于文档和查询词的模糊集表示法. （2）通过利用模糊聚类分析理论，研究了基于模糊集文档的模糊聚类方法，并得到了分类的文档簇，同时研究了文档簇的模糊集表示法，为后续研究做铺垫. （3）为了提高检索效率，可以通过缩小检索范围来实现，据此提出了基于文档簇的模糊信息检索模型，从而得到满足条件的文档簇. （4）为了对满足条件的文档簇中的文档进行排序，提出了基于文档的模糊信息检索模型，从而完成了检索的剩余工作，并形成完整的检索过程. （5）通过提出算例，分两种情况进行了分析：当文档集和查询项都是用模糊集表示的，分析了基于模糊集的模糊信息检索模型；当文档集是模糊集表示，查询项是确定的布尔类型，分析了基于模糊集的扩展布尔检索模型. 关键词：模糊集；聚类分析；信息检索；检索模型；布尔检索 Fuzzy mathematics application in information retrieval Abstract: For improving the information retrieval accuracy and efficiency of searching, this paper, which puts information retrieval as application background and gradually introduces the fuzzy mathematical theory, puts forward the following thoughts and methods: (1) In order to improve retrieval accuracy, this paper, according to the fuzzy sets theory, put forward the fuzzy sets representations, based on both the inquiry word and the document. (2) Through fuzzy clustering analysis theory, we study the fuzzy clustering analysis method based on the document cluster and acquire the classification of the cluster. And we also study the representation of the document classification, based on the fuzzy sets. It is laying groundwork for the follow-up study. (3) In order to improve the search efficiency, we can do it through narrowing the searching range. So the paper puts forward the fuzzy information retrieval model, which is based on the document cluster. Then we get meet the satisfied document clusters. (4) In order to sort the satisfied document clusters, we put forward the fuzzy information retrieval model, which is based on the document. Thus we complete the surplus work of retrieval, forming a complete search process. (5) By presenting examples, two cases were analyzed: when the sets of documents and query terms are represented by fuzzy sets, we analyze the fuzzy information retrieval model based on the fuzzy sets; when the set of