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文章研究安踏公司的商品销售额的预测问题,依据商品销售额的灰色特征及随机性特点,将GM(1,1)模型与Markov链模型相结合,建立GM(1,1)-Markov耦合模型,应用该模型对安踏以半年为期的商品销售额进行实例预测。对GM(1,1)模型进行了精度检验,检验结果表明GM(1,1)有较高的预测精度。在此基础上引入Markov链进行预测值修正,其中,GM(1,1)模型预测的平均相对误差为7.67%,而通过Markov链模型进行优化后,GM(1,1)模型平均相对误差为3.71%。说明,经Markov链优化的GM(1,1)模型的预测精度优于GM(1,1)模型,更具实用性。 相似文献
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基于灰色系统理论的经济预测模型研究 总被引：2，自引：0，他引：2
分析了灰色系统理论用于经济预测的可行性,介绍了灰色系统理论的两种模型:灰色GM(1,1)模型和动态等维GM(1,1)模型,并介绍了包括"未知数据法"在内的各种模型检验方法,通过一个实例将上述模型用于预测并对结果进行检验.结果表明,灰色系统理论可以用于经济预测且动态等维GM(1,1)模型比传统的GM(1,1)模型预测精度高,预测结果更可靠. 相似文献
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本文介绍了灰色系统GM(1,1)模型的预测方法,并应用数据对数化灰色系统GM(1,1)模型,通过实例对1992年的中文期刊订购经费进行外推预测,结果表明:应用数据对数化灰色系统GM(1,1)模型的拟合与外推效果好,是一个最佳的外推预测模型。 相似文献
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本文通过对GM(1,1)灰色水质预测法研究进展的相关介绍,分析了GM(1,1)灰色水质预测法模型理论研究,并实现了GM (1,1)灰色模型的matlab程序化。 相似文献
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在使用常规GM(1,1)模型进行预测时,对于落后的旧数据的模拟精度较高,而对于未来的新数据的预测精度较低,这给地铁基坑施工监测和预测带来了不便,进而影响施工安全。针对常规GM(1,1)模型的不足,文章利用初始条件优化的新陈代谢GM(1,1)模型,结合长沙地铁某车站深基坑开挖过程中的实测数据,进行常规GM(1,1)模型和新陈代谢GM(1,1)模型的计算比较。结果表明,初始条件优化的新陈代谢GM(1,1)模型精度较高,预测误差较小,有很好的使用价值,对地铁基坑的安全施工起到了一定的作用。 相似文献
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文中应用灰色系统理论的GM(1,1)模型对招生人数进行了预测。算例表明,GM(1,1)预测方法精确性好,实用性强。 相似文献
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首先以情报学为例,通过关键词综合评价,得出情报学近18年的6组学科创新力值,并分别用GM(1,1)全模型、GM(1,1)部分模型、GM(1,1)新信息模型和GM(1,1)新陈代谢模型对学科创新力的6组值进行模拟,通过分析比较,得出GM(1,1)新陈代谢模型具有较高精度,然后选取该模型对情报学学科创新力进行预测。接着计算图书馆学近12年的4组学科创新力数据,建立图书馆学学科创新力GM(1,1)新陈代谢模型,用该模型对图书馆学创新力进行预测。最后将图书馆学与情报学学科创新力进行比较和分析,得出情报学和图书馆学不同的学科特点和发展趋势。 相似文献
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灰色模型在图书馆管理研究预测中的应用 总被引：6，自引：0，他引：6
介绍了灰色GM(1,1)模型,利用1998~2004年图书馆管理研究文献量的统计数据,建立了文献总量和两个主要专题文献量的灰色GM(1,1)预测模型。经检验,该模型全部合格,并利用灰色GM(1,1)模型对图书馆管理研究的发展趋势进行了拟合预测。 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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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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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
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Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
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Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
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Leah A. Lievrouw 《The Information Society》1998,14(2):83-96
The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests. 相似文献