Finding what is missing from a digital library: A case study in the Computer Science field

This article proposes a process to retrieve the URL of a document for which metadata records exist in a digital library catalog but a pointer to the full text of the document is not available. The process uses results from queries submitted to Web search engines for finding the URL of the corresponding full text or any related material. We present a comprehensive study of this process in different situations by investigating different query strategies applied to three general purpose search engines (Google, Yahoo!, MSN) and two specialized ones (Scholar and CiteSeer), considering five user scenarios. Specifically, we have conducted experiments with metadata records taken from the Brazilian Digital Library of Computing (BDBComp) and The DBLP Computer Science Bibliography (DBLP). We found that Scholar was the most effective search engine for this task in all considered scenarios and that simple strategies for combining and re-ranking results from Scholar and Google significantly improve the retrieval quality. Moreover, we study the influence of the number of query results on the effectiveness of finding missing information as well as the coverage of the proposed scenarios.     

搜索引擎偏见:合理性与不合理性——从百度竞价排名风波说起

百度竞价风波是搜索引擎偏见的典型体现。以竞价排名为特征的搜索引擎偏见与生俱来,具有一定的合理性,同时也具有严重的消极后果:伤害了新闻自由和个人自治,破坏了民主制度的基础和市场规则,违反了相关法律。如何减少和消除搜索引擎偏见,维护新闻自由,维持媒介市场秩序,促进个人和组织自治,推进民主进程,推动人类全面发展,值得深思。     

电控发动机水温过高的故障诊断

以电控发动机冷却系统的结构与工作原理为基础,分析发动机水温过高的故障原因并通过维修实例进行证明,总结出汽车发动机水温过高故障的常用诊断流程.     

谷歌数字图书馆研究现状综述

综述国内外学者对谷歌数字图书馆法律问题研究、竞争与反垄断研究、影响研究的现状,认为国内外学者对谷歌数字图书馆的研究均存在不足,国内学者对谷歌反垄断与竞争、和解协议、optout等众多领域未给予关注或研究深度不足,对我国版权法的完善未给出具有建设性的意见等,并提出相应建议。     

Search engines and the public use of reason

How should the policies of search engines and other information intermediaries be ethically evaluated? It is argued that Kant’s principles for the public use of reason are useful starting points for the formulation of criteria for such an evaluation. The suggestion is, furthermore, that a search engine can be seen to provide a testimony to the user concerning what information that is most relevant to her query. This suggestion is used as the basis for the development of a broadly Kantian account of a rational searcher. It is argued that the search engine companies are morally required to publish their information policies and act in accordance with them but given the threat of search engine spam they can have no obligation to publish the details of their algorithms.     

开放式搜索引擎在Web网站中的应用研究

对于专业商务Web网站 ,既要求高效、可靠的数据管理和业务管理 ,又需要对海量数据进行快速、准确的检索。本文比较了关系数据库和非关系数据库的优缺点 ,提出开放式搜索引擎在这方面应用的优势 ,并以中国企业和产品数据库为例 ,介绍了利用Search’97搜索引擎开发专业商务网站检索系统的过程     

搜索引擎的“规范化”发展

本文通过对现有搜索引擎分析，提出搜索引擎的改进措施，包括两个方面：网络信息发布和信息采集的规范化：引入元数据；网络信息组织和检索方面的规范化控制：引入检索语言，重点讨论了词表和专业搜索引擎的结合问题。     

柴油机工作过程均匀性的相关分析监测

将信号分析技术应用于柴油机缸内工作过程均匀性的检测与诊断，对缸内气体压力的互相关函数、互功率谱密度函数、相干函数的特征及其与柴油机工作状态之间的关系进行了分析讨论。研究表明，利用相关分析方法来监测各缸工作过程的差异是可行的。     

柴油机活塞-缸套磨损故障振动诊断机理的研究

通过对活塞组横向撞击的理论分析和活塞－缸套磨损故障的模拟试验，揭示了机身侧面振动的内部激励源及其与柴油机工况、活塞－缸套磨损间隙的内在联系，讨论了故障诊断中振动特征参量的优化选择问题，提出了一种适用于多种机型柴油机不同工况下活塞－缸套工作间隙的振动监测方法。