通过模糊集合检索模型的规范描述,本文首先定义了检索系统中检索效率和系统效率之间的函数关系,并应用该函数关系对比分析模糊集合检索系统和标准布尔检索系统的性能,指出模糊集合检索系统所面临的“囚徒困境”:检索效率的提升引起了系统效率的下降。之后针对“囚徒困境”,从词词关联矩阵方面来改进模糊集合检索策略,寻求到解决“囚徒困境”的思路和技术手段。最后借助SQL语言演示词词关联矩阵的两种构造策略,建立数学模型分析词词关联矩阵构造的最优时机,并确立该思路为一种新的系统开发模式。根据时机来合理选择词词关联矩阵构造策略有助于改善现有模糊集合检索算法的执行效率,实现检索效率和系统效率的双赢。
Firstly, through the normative description of Fuzzy retrieval model, we define the functional relationship between retrieval efficiency and system efficiency in the retrieval system. Applying the function to the performance analysis of comparison between Fuzzy retrieval system and Boolean retrieval system, we point out the problem of prisoner's dilemma which fuzzy retrieval model has to face: the increase of retrieval efficiency brings about the decrease of system efficiency. Secondly, in the view of key-word connection matrix, this article proposes the idea and technical means to solve the prisoner's dilemma. Finally, focusing on the constructing of keyword connection matrix, we demonstrate two kinds of constructing strategy using structure query language, build the mathematical model to analyze the optimal timing of constructing and establish this solution as a new kind of system development model. It is helpful to improve the algorithms execution efficiency and achieve win -win in system efficiency and retrieval efficiency that we choose the right constructing strategy according the timing.