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开展基于社会化标签系统、搜索引擎和分类目录3种平台的信息搜寻实验,从相对查全率、相对查准率两个指标的角度比较分析社会化标签系统与其他网络信息搜寻系统的搜寻效率。研究发现,搜索引擎的相对查全率和相对查准率最高,社会化标签系统的搜寻效率也有一定的优势。分类目录比社会化标签的相对查准率低,两者的相对查全率接近。对于某些特定的信息需求,社会化标签系统的搜寻效率甚至超过了搜索引擎。 相似文献
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网络信息检索的检全率、检准率影响因素研究 总被引：5，自引：0，他引：5
主要介绍信息检索系统评价的两个常用指标--检全率、检准率,从信息源、搜索引擎检索机制、用户与系统的交互过程3方面分析网络环境下影响它们的因素,并对如何克服不良因素,提高检索质量提出一些建议。 相似文献
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交互式跨语言信息检索是信息检索的一个重要分支。在分析交互式跨语言信息检索过程、评价指标、用户行为进展等理论研究基础上,设计一个让用户参与跨语言信息检索全过程的用户检索实验。实验结果表明:用户检索词主要来自检索主题的标题;用户判断文档相关性的准确率较高;目标语言文档全文、译文摘要、译文全文都是用户认可的判断依据;翻译优化方法以及翻译优化与查询扩展的结合方法在用户交互环境下非常有效;用户对于反馈后的翻译仍然愿意做进一步选择;用户对于与跨语言信息检索系统进行交互是有需求并认可的。用户行为分析有助于指导交互式跨语言信息检索系统的设计与实践。 相似文献
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从信息采集成本收益律、对数透视法则、信息栈理论的介绍和分析入手,分析企业决策支持系统的信息基础建设应遵循的规律。 相似文献
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数字图像管理系统模型设计与实现 总被引：1，自引：0，他引：1
从用户角度出发,设计一个面向大众用户的,集数字图像采集、处理、存储和检索等功能于一体的数字图像管理系统模型,并研究标注词的数量对于语义检索的准确率和召回率的影响。实验表明,本系统模型能够满足大众用户对于数字图像管理的需求。 相似文献
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文献推荐系统：提高信息检索效率之途 总被引：2，自引：0，他引：2
Traditional Information Retrieval (IR) systems have limitations in improving search performance in today’s information environment. The high recall and poor precision of traditional IR systems are only as good as with the accuracy of search query, which is, however, usually difficult for the user to construct. It is also time-consuming for the user to evaluate each search result. The recommendation techniques having been developed since the early 1990s help solve the problems that traditional IR systems have. This paper explains the basic process and major elements of document recommender systems, especially the two recommendation techniques of content-based filtering and collaborative filtering. Also discussed are the evaluation issue and the problems that current document recommender systems are facing, which need to be taken into account in future system designs. Traditional Information Retrieval (IR) systems have limitations in improving search performance in today’s information environment. The high recall and poor precision of traditional IR systems are only as good as with the accuracy of search query, which is, however, usually difficult for the user to construct. It is also time-consuming for the user to evaluate each search result. The recommendation techniques having been developed since the early 1990s help solve the problems that traditional IR systems have. This paper explains the basic process and major elements of document recommender systems, especially the two recommendation techniques of content-based filtering and collaborative filtering. Also discussed are the evaluation issue and the problems that current document recommender systems are facing, which need to be taken into account in future system designs. 相似文献
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《The Reference Librarian》2013,54(23):135-152
The goal of our research project is to explore the use of new technologies in providing more sophisticated delivery systems for information services in situations where the services of skilled reference librarians are not available. We are working on developing an advanced function workstation equipped with a CD-ROM jukebox of reference books and vocabulary control tools on laser dlsks with keyword access. The user interface will include an expert system to guide users in selecting the types of material best suited to their needs. It will also provide guidance in developing the best search strategy by mapping the terms selected by the users to the more controlled vocabularies of the data bases. Searches that are too broad and yield too much material will be narrowed. Conversely, searches that are too specific will be broadened. The system will also be designed to connect to a full service integrated library network also enabling the user to access the on-line card catalog, check circulation and do interlibrary loans. In developing this system we will be taking advantage of many new technologies including the advanced function workstations, expert systems components, hypertext and optical disk storage. 相似文献
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西方信息共享的理念及其法律保障体系及其启示 总被引：1，自引：0，他引：1
符合当代社会需求的信息数据共享的动因与较完善的法律保障体系，是保证
信息数据共享得以顺利开展的首要前提。欧洲《布加勒斯特宣言》突出了信息共享对社
会发展的重要作用，强调了信息共享符合信息社会的要求，有利于发展民主制度，有利
于维护公民获得信息和知识的权利。美国和欧盟已经建立了较完善的信息共享法律保障
体系。我国需要加强信息数据共享法律保障体系的建设，而保障信息共享的法规体系应
涉及到多领域相关法规体系的建设与完善。 相似文献
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认为目前NSTL文献检索系统采用的是传统的基于关键词匹配的检索方法,影响检索结果的查准率和查全率。为提高检索服务的质量,利用文献中的语义信息资源,构建语义资源库,并介绍语义资源的提取方法、语义资源库的结构与构建方法,及其应用于NSTL系统中并实现检索结果聚类和推荐的功能,以方便用户对检索结果的浏览和理解。 相似文献
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Collaborative filtering (CF) is a popular method for personalizing product recommendations for e-commerce applications. In order to recommend a product to a user and predict that user’s preference, CF utilizes product evaluation ratings of like-minded users. The process of finding like-minded users forms a social network among all users and each link between two users represents an implicit connection between them. Users having more connections with others are the most influential users. Attacking recommender systems is a new issue for these systems. Here, an attacker tries to manipulate a recommender system in order to change the recommendation output according to her wish. If an attacker succeeds, her profile is used over and over again by the recommender system, making her an influential user. In this study, we applied the established attack detection methods to the influential users, instead of the whole user set, to improve their attack detection performance. Experiments were conducted using the same settings previously used to test the established methods. The results showed that the proposed influence-based method had better detection performance and improved the stability of a recommender system for most attack scenarios. It performed considerably better than established detection methods for attacks that inserted low numbers of attack profiles (20–25 %). 相似文献
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泛在知识环境下的信息检索课教学 总被引：5，自引：1，他引：5
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提出基于不完全模糊语言的高校数字图书馆信息资源推荐系统,该系统中,用户兴趣模型的建立不要求用户直接提供偏好信息,而是允许用户通过不完全模糊语言偏好关系来表达个人偏好,这样既为用户节省时间和精力,又能获取更加准确的用户偏好,从而大大提高推荐精度。系统同时还引入"用户协作偏好",有助于用户开展多学科研究或参与合作研究项目。 相似文献
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元搜索引擎性能评价体系研究 总被引：1，自引：0，他引：1
对于元搜索引擎的比较与评价研究在我国还是空白,本文在借鉴单一搜索引擎评价以及国外学者研究的基础上,初步提出了元搜索引擎评价的主要性能指标,并对一些主要的元搜索引擎的性能和特点做了简要说明,这对于元搜索引擎的发展和用户都是有益的.参考文献8. 相似文献
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为了增强检索效率,信息检索系统必须对用户的信息搜寻活动提供更有效的支持,为达到这一目的,需要更好地理解用户同信息系统间交互的本质。信息检索交互模型能帮助分析、理解这些交互以及如何实现相应的支持。 相似文献
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文章对ISO、IEC、ITU、CEN等主要国际标准文献检索平台进行了系统调研,并从收录内容、检索方式、著录方式及检索结果四个方面作了分析、评价与比较,以便用户选择使用。最后,针对我国标准检索平台重质量轻数量、检索字段少、检准率和检全率低、收录不全、更新慢等不足给出了相关建议,包括提高著录质量、增加检索字段、提供多语言检索和检索结果的多种排序方式、提高时效性和连续性、整合标准文献。 相似文献
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浅谈网络环境下的信息检索效率 总被引：5，自引：0，他引：5
网络环境下，信息检索效率主要是指检全率和检准率，它们之间存在互逆、互顺等关系。许多因素影响着检索效率，文章提出了提高检索效率的各种策略，并且展望了其发展趋势。 相似文献
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《International Information and Library Review》1998,30(2):105-122
This article classifies information retrieval applications into three classes depending on the correspondence between a user's request and the queries posed to the document base. It is argued that the mapping of requests (on a semantic level) to formalized queries (often on a lexical level) determines the range of retrieval effectiveness that may be obtained and that this classification may explain the discrepancy found in some information retrieval tests. It may also shed new light on a debate in the profession about the efficiency of retrieval systems in relation to precision, recall and information overload. 相似文献