Impact of commercial search engines and international databases on engineering teaching and research

For the last three decades, the engineering higher education and professional environments have been completely transformed by the ‘electronic/digital information revolution’ that has included the introduction of personal computer, the development of email and world wide web, and broadband Internet connections at home. Herein the writer compares the performances of several digital tools with traditional library resources. While new specialised search engines and open access digital repositories may fill a gap between conventional search engines and traditional references, these should be not be confused with real libraries and international scientific databases that encompass textbooks and peer-reviewed scholarly works. An absence of listing in some Internet search listings, databases and repositories is not an indication of standing. Researchers, engineers and academics should remember these key differences in assessing the quality of bibliographic ‘research’ based solely upon Internet searches.     

搜索引擎的发展探述

对第二代搜索引擎的现状进行了全面客观的分析,总结归纳出其当今所面临的困境,并以此为基础,提出了搜索引擎将采用何种新技术来提高搜索引擎的性能,实现更加智能化、个性化的搜索     

一种个性化Agent元搜索引擎技术

在使用元搜索引擎进行检索的过程中,由于返回结果的数量较大,不利于用户快速、准确地找到所需信息.本文提出一种基于Agent的元搜索引擎结果优化技术,旨在通过建立需求模型对检索结果进行优化,从而针对用户各自不同的需求提供更具个性化的信息.     

Internet信息最优查询设计

本文分析了信息查询的方法及主要搜索引擎的特点，设计了信息最优查询的步骤及检索策略。     

情报检索的理论和方法在改善搜索引擎搜索性能中的应用

本文认为计算机情报检索的理论与方法对改善搜索引擎的搜索性能具有重要意义，并从索引数据库和检索功能两方面探讨了改善其搜索性能的措施。     

搜索引擎“沙盒效应”的研究及分析

搜索引擎＂沙盒效应＂是这几年的热门话题,很多网站遭遇过类似情况,＂沙盒效应＂也会给新生网站带来麻烦,怎样走出＂沙盒效应＂对网站来说有着非常重要的意义。     

学术搜索引擎的特点及发展趋势——基于Google Scholar、百度国学、CNKI、Scirus的比较研究

百度国学和CNKI是国内两个重要的中文学术搜索引擎,Google Scholar和Scirus是国际公认的专业学术搜索引擎,介绍了它们各自的特点及其功能,分别从数据库、检索功能、检索结果与用户界面3个方面来比较分析了它们各自的异同点,并对学术搜索引擎的发展趋势做了展望。     

Comparing rankings of search results on the Web

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.     

利用分类法和主题法改善搜索引擎的性能

本文对Internet上的检索工具搜索引擎的工作机理和性能进行了全方位的探讨，指出了常见搜索引擎信息检索缺点。同时还指出了Meta搜索引擎、智能搜索引擎和代理搜索引擎虽然提高了网络信息检索的质量，但由于分类体系不统一，类目划分标准模糊，因而仍然未能从根本上改变搜索引擎主要以关键词（自然语言）作为检索入口的现状，不能实现分类检索与主题检索的一体化。要实现搜索引擎信息检索的突破，笔者认为有必要运用情报检索语言的理论和方法来完善因特网搜索引擎的性能，实现分类、主题一体化的检索机制，克服分类检索语言单纯以学科聚类、主题语言单纯以事物聚类的局限性。     

发动机原理课程教学改革的探索与实践

分析了＂发动机原理＂课程的特点和教学现状,针对该课程中存在的一些问题,提出进行教学改革的必要性和教学改革的方向,并对＂激发学习兴趣＂、＂互动交流＂等教学方法进行了探索。