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针对云计算中的任务调度的存在效率低的问题,首先分析了云计算任务调度目标,其次,对蚁群算法的信息素设置质量函数、对选择概率设置经验反馈因子进行了改进,对帝国竞争算法中的殖民地计算方式、边界值的处理都采用了新的方式,最后将两种算法进行融合,得到基于蚁群算法-帝国竞争算法的云计算任务调度算法,仿真实验中,在任务执行时间,执行成本和负载率方面,本文算法都具有一定的优越性。 相似文献
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针对传统的蚁群算法在云计算中存在任务调度效率低的问题,本文将共生演算法引入到蚁群算法中,首先将蚁群算法分解为2个子群,并使用共生演算法中的共生,共栖和寄生虫机制避免了算法陷入局部最优,加速了算法获得最优解,在云计算调度仿真中,基于蚁群算法-共生演算法在虚拟机负载均衡、任务完成时间,任务完成成本等方面都有良好的表现,说明本文算法能够有效的提高云计算任务调度效率。 相似文献
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针对粒子群算法在云计算任务调度中存在效率低等问题,提出在将鸡群算法引入到粒子群算法中,将粒子的分布按照鸡群算法中的公鸡,母鸡和小鸡来进行区分,同时对粒子的学习因子进行了改进,有效的避免算法陷入局部,收敛速度快的缺点,在云计算仿真平台中,将本文算法与粒子群算法,鸡群算法在虚拟机负载均衡,消耗成本和完成时间上进行对比都取得了一定的优势,说明本文算法能够有效的提高云计算任务调度效率。 相似文献
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针对云计算任务调度中存在效率低,提出了基于改进的蝙蝠算法(improved bat alogrithm,IBA)云任务调度.首先,建立了以执行时间和负载均衡的调度模型,其次在蝙蝠算法的初始化中采用混沌映射,提高了种群的多样性;在蝙蝠算法的自适应参数使用指数递减因子代替;在每一次迭代后使用量化正交交叉算子进行个体筛选.最后,在仿真实验中,IBA算法相比于蚁群算法、粒子群算法,蝙蝠算法都具有较好的调度效果. 相似文献
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针对云计算下的负载均衡存在效率低的问题,本文首先在鲸鱼算法的基础上,通过种群初始化,淘汰和竞争机制提高算法的局部搜索能力,然后通过人工蜂群算法进行融合提高算法全局搜索能力,融合后算法用于云计算负载均衡中,在调度时间跨度,负载均衡度和任务平均等待时间方面都具有较好效果。 相似文献
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云平台多处理器的任务调度是解决庞大用户群中庞大任务量和数据量的关键,云平台中任务调度的计算性能影响整个系统的运行效率。提出一种基于任务信息流特征尺度谱分析的开销折减算法,采用可分解特征下的云平台任务同步开销折减算法,通过构建复杂通道下多处理器运行环境下的云平台任务调度整合基础模型,进行任务节点信息表征,使用GSM、TD-SCDMA、TD-LTE和WLAN,实现多处理器和多通道任务调度,计算各任务匹配资源的效率,得到资源相似度,基于任务信息流特征尺度谱分析方法计算每个任务的特征尺度,得到尺度优化的开销折减目标函数。仿真结果表明,采用该算法进行任务调度,具有较高的执行效率,CPU利用率高,网络开销折减幅度较高,提高了数据通信效率。 相似文献
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云计算资源负荷状态的动态变化,使得如何预测其变化情况,从而合理地实施任务调度,成为亟待解决的问题。针对该问题,提出一种基于资源组合预测的云计算任务调度算法。该模型采用偏最小二乘回归从各种单一模型的预测结果中提取有效成分,建立组合预测模型;再依据对资源结点的资源预测结果和最小完成时间原则实施任务调度。仿真测试结果表明,该算法具有较好的性能与负载均衡性。 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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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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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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《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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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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《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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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