基于网页摘要分析的元搜索引擎研究*

针对目前搜索引擎返回结果的海量性，构建一个元搜索引擎，旨在高效利用多个成员搜索引擎返回的结果。介绍元搜索引擎的基本架构及当前结果融合的主要方法，应用统计学方法研究网页标题、网页摘要与网页文本之间的相关性关系，从而确定相关度权值进行结果相关性判断。实验证明，元搜索引擎搜索结果的平均准确率比各个成员引擎的搜索结果平均准确率都有较大提高。     

高校图书馆读者服务透视

21世纪是知识和信息的时代,图书馆作为信息枢纽和公益性科学文化传播的重要园地,在社会经济发展中的地位越来越重要。高校图书馆肩负着培养和造就国家未来建设人才的神圣职责,因此,研究和探索做好高校图书馆读者服务工作的途径,提高读者服务质量,是人们普遍关注的问题。     

用户查询信息障碍分析及对策初探

知识经济时代的到来、网络技术的普及、信息环境的演变,使得人们对知识、信息的需求与消费成为新的消费热潮。然而,用户在查询信息方面的障碍却依然存在,且有了新的变化。本文客观分析了障碍,并从解决方法上提出了自己的观点。     

共引分析理论与实践进展

共引分析是一种重要的情报研究方法。系统总结了共引分析理论与方法的发展过程; 分析了共引分析在应用和实践层面,特别是科学结构揭示方面的进展。参考文献15。     

图书馆图书采购模型的探讨与应用

通过定量分析方法,建立了资金在各图书类别中的分配模型,以及同类别下不同图书复本量的确定模型。模型有助于合理分配资金,达到图书采购预期效用。表1。图2。公式1。参考文献6。     

概念地图及其结构分析在知识评价中的应用(Ⅲ):实证研究

进行概念地图的结构分析可以在一定程度上有效地评价知识。对概念地图作为知识评价工具的研究框架进行了实证分析;提出了18个概念地图结构分析的测量指标,并验证了这些指标的信度和效度。对概念地图及结构分析在知识评价中应用的实证研究,为进一步利用概念地图全面评价知识奠定了基础。表3。图4。参考文献46。     

公共图书馆事业与国民经济协调发展量化分析

图书馆事业是推动国民经济发展的重要因素之一。目前,国家财政投入尚远远不能满足公共图书馆事业发展的需要,投入占国家财政支出比重下降,公共图书馆总支出和投入基数偏低,事业发展也很不平衡。公共图书馆事业与国民经济的协调发展,应从保证公共图书馆事业公益性主体地位、将其作为国民经济和社会发展的基础设施予以重视,并先于国民经济和社会发展来做起。图5。表6。参考文献8。     

Analysis of the urban/rural broadband divide in Canada: Using GIS in planning terrestrial wireless deployment

Millions of Canadians residing in Canada's northern, isolated, rural, and remote communities do not have broadband Internet access. This situation has led to a national “broadband divide.” That is, the deployment of wireline broadband is very limited in Canada's northern, isolated, rural, and remote areas because of the significant expense of installation and maintenance of the wired infrastructure needed to reach dwellings in these locations.Terrestrial broadband wireless technology, on the other hand, does not entail the same kind of physical infrastructure. As a result, there are dramatic changes in how spatial considerations affect the provision of broadband Internet services (BIS) to areas beyond the urban zone. In particular, the spatial question is now focused on assessing the capacity for different technological solutions to reach profitable population bases, and brings to the forefront organizations that are developing non-line-of-sight (NLOS) technologies that would permit wireless Internet access over much greater distances than current solutions.We begin this paper by establishing the importance of broadband connectivity to Canada's northern, isolated, rural, and remote communities. This discussion comments on the role of the Government of Canada in the provision of broadband connectivity to residents of these communities, and outlines the current regulatory issues that govern wireless services and policy formulation.The second part of the paper illustrates the use of geographic information system (GIS) approaches in the study of wireless broadband planning and deployment. Case study findings suggest that GIS applications can make a significant contribution to the analysis of wireless deployment planning, to the understanding of the relationships between wireless signal sources and consumers, and to the spatial configuration of terrestrial wireless broadband networks. We conclude the paper by discussing how the GIS approach employed could be used to inform the public policy process with regard to increasing access to broadband Internet services in all regions of the country, and thereby providing the opportunity for all Canadians, regardless of location, to fully participate in the Information Society.     

Hierarchical clustering of a Finnish newspaper article collection with graded relevance assessments

Search facilitated with agglomerative hierarchical clustering methods was studied in a collection of Finnish newspaper articles (N = 53,893). To allow quick experiments, clustering was applied to a sample (N = 5,000) that was reduced with principal components analysis. The dendrograms were heuristically cut to find an optimal partition, whose clusters were compared with each of the 30 queries to retrieve the best-matching cluster. The four-level relevance assessment was collapsed into a binary one by (A) considering all the relevant and (B) only the highly relevant documents relevant, respectively. Single linkage (SL) was the worst method. It created many tiny clusters, and, consequently, searches enabled with it had high precision and low recall. The complete linkage (CL), average linkage (AL), and Ward's methods (WM) returned reasonably-sized clusters typically of 18–32 documents. Their recall (A: 27–52%, B: 50–82%) and precision (A: 83–90%, B: 18–21%) was higher than and comparable to those of the SL clusters, respectively. The AL and WM clustering had 1–8% better effectiveness than nearest neighbor searching (NN), and SL and CL were 1–9% less efficient that NN. However, the differences were statistically insignificant. When evaluated with the liberal assessment A, the results suggest that the AL and WM clustering offer better retrieval ability than NN. Assessment B renders the AL and WM clustering better than NN, when recall is considered more important than precision. The results imply that collections in the highly inflectional and agglutinative languages, such as Finnish, may be clustered as the collections in English, provided that documents are appropriately preprocessed.     

我国图书馆学情报学基金论文产出力调查研究与定量分析

调查研究1996～2003年4月间我国图书馆学、情报学基金论文情况(包括论文数量、类别及年代分布、期刊分布、主题分布)和基金论文作者情况(包括作者系统分布、地区分布、多产作者分布、职称分布、合作类型分布)，并对有关数据进行定量分析。