Dictionary-based text categorization of chemical web pages     

Chun-Yan Liang  Li GuoZhao-Jie Xia  Feng-Guang NieXiao-Xia Li  Liang SuZhang-Yuan Yang 《Information processing & management》2006

A new dictionary-based text categorization approach is proposed to classify the chemical web pages efficiently. Using a chemistry dictionary, the approach can extract chemistry-related information more exactly from web pages. After automatic segmentation on the documents to find dictionary terms for document expansion, the approach adopts latent semantic indexing (LSI) to produce the final document vectors, and the relevant categories are finally assigned to the test document by using the k-NN text categorization algorithm. The effects of the characteristics of chemistry dictionary and test collection on the categorization efficiency are discussed in this paper, and a new voting method is also introduced to improve the categorization performance further based on the collection characteristics. The experimental results show that the proposed approach has the superior performance to the traditional categorization method and is applicable to the classification of chemical web pages.  相似文献   

Comparing rankings of search results on the Web   总被引：1，自引：0，他引：1  

Judit Bar-Ilan   《Information processing & management》2005,41(6):1511-1519

The Web has become an information source for professional data gathering. Because of the vast amounts of information on almost all topics, one cannot systematically go over the whole set of results, and therefore must rely on the ordering of the results by the search engine. It is well known that search engines on the Web have low overlap in terms of coverage. In this study we measure how similar are the rankings of search engines on the overlapping results.We compare rankings of results for identical queries retrieved from several search engines. The method is based only on the set of URLs that appear in the answer sets of the engines being compared. For comparing the similarity of rankings of two search engines, the Spearman correlation coefficient is computed. When comparing more than two sets Kendall’s W is used. These are well-known measures and the statistical significance of the results can be computed. The methods are demonstrated on a set of 15 queries that were submitted to four large Web search engines. The findings indicate that the large public search engines on the Web employ considerably different ranking algorithms.  相似文献   

搜索引擎的选择与检索策略   总被引：8，自引：0，他引：8  

卢晓勤 《情报科学》2002,20(4):418-420

本文根据目前国内外搜索引擎研究状况，针对搜索引擎中出现的问题，提出了搜索引擎的选择方法，及利用技巧和策略。  相似文献   

Improvement of building field association term dictionary using passage retrieval     

Uddin Md.  Elmarhomy  Elsayed  Masao  Kazuhiro  Jun-ichi 《Information processing & management》2007,43(6):1793

Field Association (FA) terms are a limited set of discriminating terms that can specify document fields. Document fields can be decided efficiently if there are many relevant FA terms in that documents. An earlier approach built FA terms dictionary using a WWW search engine, but there were irrelevant selected FA terms in that dictionary because that approach extracted FA terms from the whole documents. This paper proposes a new approach for extracting FA terms using passage (portions of a document text) technique rather than extracting them from the whole documents. This approach extracts FA terms more accurately than the earlier approach. The proposed approach is evaluated for 38,372 articles from the large tagged corpus. According to experimental results, it turns out that by using the new approach about 24% more relevant FA terms are appending to the earlier FA term dictionary and around 32% irrelevant FA terms are deleted. Moreover, precision and recall are achieved 98% and 94% respectively using the new approach.  相似文献   

利用网络日志分析提高搜索引擎的检准率   总被引：2，自引：0，他引：2  

葛蓉 《情报科学》2004,22(10):1250-1253

本文详细介绍了搜索引擎的发展现状和网络日志分析技术。在此基础上。探讨了如何利用网络日志分析提高搜索引擎的检准率。  相似文献   

搜索引擎网页快照的实现与安全     

孙静  赵恒永 《中国科技信息》2007,(11):138-139,141

文章介绍了搜索引擎网页快照系统的实现以及在安全性能方面的研究。当前的多数搜索引擎网站提供的网页快照,能够使用户更加快速和方便地访问较早时期的网页,但它们并没有对其中的网页安全进行判断。文章中的网页快照系统在实现网页快照的同时,通过建立网页脚本语言学习解释器,运用机器学习技术、词法分析技术等对网页上可能存在的不安全代码进行判断和去除,从而保证提供给用户的是尽量安全的网页快照。  相似文献   

新一代中文智能搜索引擎尤里卡研究   总被引：3，自引：1，他引：3  

李村合 《情报科学》2003,21(1):86-88

本文介绍了Internet新一代中文智能搜索引擎尤里卡的基本情况，它能对自然语言查询进行语义理解，克服了传播搜索方法与语义无关的缺点。研究了该搜索引擎的使用方法与技巧，同时客观地评价了它的优劣得失，指出需进一步完善之处。  相似文献   

搜索引擎搜索结果的评价技术   总被引：6，自引：0，他引：6  

陶跃华  孙茂松 《情报科学》2001,19(8):861-863,873

搜索引擎根据用户查询在自己的索引数据库中进行查找，并根据相关性分析将查询结果返回给用户。本文就传统信息检索系统的性能效率评价技术,针对Internet的特点，对搜索引擎搜索结果的评价进行了讨论。  相似文献   

搜索引擎应对网站作弊的搜索策略和用户的检索策略     

刘俊熙 《现代情报》2007,27(6):168-170,172

目前，用户需要搜索引擎提高查准；而相关网站则通过种种的手法（甚至是非法手段）来获得在搜索引擎检索结果中好的排名来为企业获取利益。本文探讨的问题是：在这种背景下，（1）搜索引擎如何制定策略来进行有针对性地搜索；（2）用户如何制定检索策略来进行有效地检索。  相似文献   

论提高中文搜索引擎质量的途径   总被引：11，自引：0，他引：11  

焦微玲 《情报科学》2002,20(1):100-102

随着网络信息数量的迅猛增长，搜索引擎的网络导航作用日益增强，然而搜索引擎自身也存在“信息过载”、“信息超量”的现象，如何克服上述现象，向用户提供数量适宜、质量优良的信息是目前迫切需要解决的问题。本文立足于本文搜索引擎，在分析了我国搜索引擎的发展状况和存在的问题之后，简单论述了可以提高中文搜索引擎质量的几条途径。  相似文献