Two-stage statistical language models for text database selection   总被引：2，自引：0，他引：2  

Hui Yang  Minjie Zhang 《Information Retrieval》2006,9(1):5-31

As the number and diversity of distributed Web databases on the Internet exponentially increase, it is difficult for user to know which databases are appropriate to search. Given database language models that describe the content of each database, database selection services can provide assistance in locating databases relevant to the information needs of users. In this paper, we propose a database selection approach based on statistical language modeling. The basic idea behind the approach is that, for databases that are categorized into a topic hierarchy, individual language models are estimated at different search stages, and then the databases are ranked by the similarity to the query according to the estimated language model. Two-stage smoothed language models are presented to circumvent inaccuracy due to word sparseness. Experimental results demonstrate that such a language modeling approach is competitive with current state-of-the-art database selection approaches.  相似文献   

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

Tuomo Korenius  Jorma Laurikkala  Martti Juhola  Kalervo Järvelin 《Information Retrieval》2006,9(1):33-53

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.  相似文献   

图书馆数字化未来的展望-《数字未来:信息时代的策略》评介     

肖永英 《大学图书馆学报》2004,22(3):86-87

介绍了《数字未来:信息时代的策略》一书的主要内容和特点。  相似文献   

桂林图书馆外文部读者分析及工作措施     

石红 《江西图书馆学刊》2004,34(2):53-54

根据对582名读所作调查，对桂林图书馆外部的读结构、读的需求情况进行了系统分析，并提出了一系列具体的工作改进建议。  相似文献   

从信息构建看未来的知识管理   总被引：4，自引：0，他引：4  

化柏林 《情报学报》2004,23(4):463-468

本文从信息构建出发 ,进而引申到知识管理与知识推理 ,最终提出了知识基础工程。在设计并实现自然语言的语法开发平台时 ,产生了构建知识库的设想。利用语法开发平台 ,就可以对自然语言的语法进行开发 ,加上一个好的算法 ,就可以对大规模文本进行自动分析。对分析过的句子进行内容提取 ,并用面向对象方法和逻辑形式进行格式化 ,得到以面向对象为特征的常识知识库和以逻辑命题为特征的专家知识库 ,这应该是知识发现、知识管理的最高层次 ,也是知识工程的核心  相似文献   

我国电子资源引进的发展策略研究   总被引：19，自引：0，他引：19  

吕慧平  胡朝德  陈益君 《情报学报》2004,23(4):490-494

针对电子资源采购的国际发展动态 ,分析我国电子资源引进的现状 ,根据电子资源自身的类型和特点 ,提出多元化、分层次引进电子资源的构想 ,并根据我国的实际情况提出相应的对策  相似文献   

试论多媒体信息检索的发展     

丁大可  李树青 《图书馆论坛》2004,24(6):204-206,272

文章通过对文本信息检索语言发展的分析，得出检索语言发展的一般规律，由此对多媒体信息检索语言的发展做出回顾和总结，同时对于多媒体信息检索语言的前景进行了展望。  相似文献   

关于自然语言检索问题   总被引：13，自引：0，他引：13  

张琪玉 《图书馆论坛》2004,24(6):211-213,145

自然语言检索当前仅在关键词检索的层次上已经实现，重点分析了全文检索所适应和不适应的检索要求及其评价，用分析说明了当前关于自然语言检索的主流观点的不切实际，指出自然语言检索的发展方向是与情报检索语言结合和融合。  相似文献   

教师参与 分类选择 集中收藏--论高校馆图书采购工作和经费分配制度改革   总被引：11，自引：0，他引：11  

宋书星 《图书馆杂志》2004,23(1):48-50

高校馆图书收藏工作的困难及其原因是多层面的，走出困境的出路在于：以学校管理体制改革保障图书收藏体制改革，实行“教师参与，分类选择，集中收藏”和经费“四级分配，专款专用”制度。  相似文献   

从五十年馆藏西文文献看国外藏学研究及藏学文献的发展   总被引：1，自引：0，他引：1  

董印红 《四川图书馆学报》2004,(1):66-68

通过对馆藏西文藏学文献的分析,以点带面,概括出国外对藏学研究及国外出版的藏学文献的特色、意义和今后的发展方向,以及国内在收藏和利用国外有关文献时应注意的问题,从而为藏学研究工作者提供更好的文献资源服务。  相似文献