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介绍了基于关联规则挖掘的信息检索模型的研究现状,提出一种基于加权正负关联规则挖掘的信息检索系统模型,阐述了该模型的设计思路、各模块的功能及其检索算法,为信息检索研究提供一些新的思路。 相似文献
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针对目前常用的信息检索算法普遍存在查询性能不高的问题。本文提出了一种基于AWAR算法的信息检索扩展查询模型,该模型首先采用传统向量空间模型算法对检索目标进行初检,然后利用最小完全加权置信度阈值生成完全加权关联规则,最后根据规则提取扩展词,得到查询结果。实验表明,基于AWAR算法的信息检索扩展查询模型的检索性能比传统向量空间模型算法和基于局部上下文分析的查询扩展的检索算法要高。 相似文献
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基于关联规则的个性化信息检索系统研究 总被引：1，自引：0，他引：1
针对信息检索的个性化需求，分析了关联规则的基本概念以及它在个性化信息检索中的运用，提出了基于关联规则的个性化信息检索系统，并给出这个系统的设计思想和体系结构，最后介绍了这个系统的主要模块功能。 相似文献
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《科技通报》2015,(8)
在数字化信息系统中,将大量网络计算资源、存储资源与软件资源等多源信息资源进行多层次异构存储,对信息资源的调度和检索成为难题。传统的多源信息检索方法采用概念格差异融合算法,无法有效识别差异化网络数据的语义特征,检索性能不好。提出一种基于概念格特征分区的多源信息检索优化算法。概念格的生成是进行数据分析、关联分析和挖掘关联规则的前提,首先给出概念格的构造模型,进行概念格特征分区,得到数据库集合的特征概率函数密度,构建满足约束条件的无冗余概念格,计算多源信息的两种相似度系数,挖掘约束关联规则,提高信息检索精度。仿真实验表明,该算法实现多源信息检索性能优越,无偏性好,精度较高。 相似文献
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以关联规则挖掘技术的发展为主线,将目前的研究方法归纳为五类:项无加权关联规则挖掘、项加权关联规则挖掘、项完全加权关联规则挖掘、负关联规则挖掘和增量挖掘,对这五类挖掘技术进行整体性阐述和比较性研究,指出了一些挖掘技术的局限性,最后展望关联规则挖掘技术在信息检索查询扩展领域中的应用前景. 相似文献
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互联网信息检索能否快速而又高效依赖于检索技术的智能化程度,而利用数据挖掘技术能够大大提高互联网信息的检索功能。本文主要讲述数据挖掘技术在互联网信息检索中的应用,并采用叶斯网络算法进行相关数据的关联。在进行应用之前,需要对检索平台进行简单的阐述,之后对数据挖掘的关联规则进行阐述分析,最后在贝叶斯算法的基础上进行实例的仿真分析。最终得到的实验结果是:结合使用贝叶斯网络算法的数据挖掘技术能够在互联网信息检索中起到智能以及个性化的作用,因此具有很大的研究价值。 相似文献
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针对差异医疗数据库在跨平台查询中出现空查询结果问题,提出一种基于智能病历语义信息关联维分析的数据库自适应实体差异识别查询方法。通过初始查询条件和医疗数据差异分布的关联维规则推测用户对查询属性的关联程度,构建基于数据库松弛阈值、属性阈值之间的病历分析实体识别模型,进行自适应松弛响应重写,实现差异数据库的实体识别和关联性差异查询。实验结果表明,新的查询方法具有较高的查全率,能够满足用户差异性的偏好与信息检索,实现医疗信息数据的准确快速查询。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献