布尔逻辑空间与系列机

本文主要讨论了布尔逻辑空间的一些性质,提出了系列机的一些新概念,并对其关系作了初步的探讨.     

Adaptive relevance feedback method of extended Boolean model using hierarchical clustering techniques

The relevance feedback process uses information obtained from a user about a set of initially retrieved documents to improve subsequent search formulations and retrieval performance. In extended Boolean models, the relevance feedback implies not only that new query terms must be identified and re-weighted, but also that the terms must be connected with Boolean And/Or operators properly. Salton et al. proposed a relevance feedback method, called DNF (disjunctive normal form) method, for a well established extended Boolean model. However, this method mainly focuses on generating Boolean queries but does not concern about re-weighting query terms. Also, this method has some problems in generating reformulated Boolean queries. In this study, we investigate the problems of the DNF method and propose a relevance feedback method using hierarchical clustering techniques to solve those problems. We also propose a neural network model in which the term weights used in extended Boolean queries can be adjusted by the users’ relevance feedbacks.     

The Effects of Conjunction, Facet Structure, and Dictionary Combinations in Concept-Based Cross-Language Retrieval

The paper studies concept-based cross-language information retrieval (CLIR). The document collection was a subset of the TREC collection. The test requests were formed from TREC's health related topics. As translation dictionaries the study used a general dictionary and a domain-specific (=medical) dictionary. The effects of translation method, conjunction, and facet order on the effectiveness of concept-based cross-language queries were studied, and concept-based structuring of cross-language queries was compared to mechanical structuring based on the output of dictionaries. The performance of translated Finnish queries against English documents was compared to the performance of original English queries against the English documents, and the performance of different CLIR query types was compared with one another. No major difference was found between concept-based and mechanical structuring. The best translation method was a simultaneous look-up in the medical dictionary and the general dictionary, in which case cross-language queries performed as well as the original English queries. The results showed that especially at high exhaustivity (the number of mutually restrictive concepts in a request) levels cross-language queries perform well in relation to monolingual queries. This suggests that conjunction disambiguates cross-language queries. An extensive study was made of the relative importance of the concepts of requests. On the basis of the classification data of request concepts it was shown how the order of facets in a query affects cross-language as well as monolingual queries.     

关于Salton扩展布尔情报检索模型的一个注记

本文指出Salton扩展布尔检索模型存在的错误 ,给出其中正确部分的一个严格证明     

量子逻辑系统及其不相容性的解决

在经典的世界中使用的是布尔逻辑系统，在一个量子的世界中使用的是量子逻辑系统，它们的代数结构分别是布尔格和正交模格，本文详细讨论了这两种代数结构，说明了量子逻辑中的不相容性问题和两种解决的方法，并进行了比较分析。     

Kleene代数有直积分解的一个条件

本文利用分明元等概念 ,讨论了Kleene代数的直积分解 ,得到了Kleene代数为既约的条件 ,并在完备的条件下给出了Kleene代数有既约分解的一个充要条件 .     

平衡的相关免疫布尔函数

对平衡的m阶相关免疫函数进行了研究，得到了两个重要结果：一个是平衡函数满足m相关免疫的充要条件，另一个是当m≥2/3n时，f（x）都是平衡的布尔函数。     

中值滤波的神经网络实现

利用信号的阈值分解,导出适合神经网络实现的信号分解和信号恢复算法。二元信号的中值滤波函数是一对称布尔函数,可以用神经网络实现中值滤波。本文给出一种中值滤波的神经网络实现结构,它具有实时中值滤波特性。     

演化计算在密码布尔函数设计中的应用

密码学中的大量问题在数学上可以表现为困难的优化问题。而演化计算是用计算机模拟大自然的演化过程,特别是生物进化过程来求解困难优化问题的一类计算模型。该文将演化计算应用于密码学领域,采用演化计算的方法来设计密码函数,与传统的数学设计方法相比,该方法可自动生成高密码特性的密码函数。     

布尔检索在Ei-compendex和CNKI中文期刊数据库中的应用区别

本文通过对Ei-eompendex和CNKI中文期刊全文数据库中布尔检索异同点的分析研究，探讨了不同信息检索系统中布尔检索的应用区别。