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1.
负载均衡是提高数据库集群系统整体性能的重要技术手段之一,其核心在于如何对实际到达的任务进行合理的动态分配.在对比分析现有数据库集群系统的负载均衡方法的基础上,提出一种新的多指标动态负载均衡方法.该方法对后端数据库节点的多个性能指标进行采样,使用多指标决策方法TOPSIS计算各个节点负载情况,用负载最轻的节点作为决策结果.实验结果表明:与传统负载均衡方法比较,该方法可显著提高集群数据库系统的整体性能. 相似文献
2.
Linux虚拟服务器(LVS)是一个虚拟的服务器集群系统。在大功率干扰下,LVS集群的抗扰动性能不好,无法有效实现IP负载均衡和任务调度。提出一种基于功率自激的大功率干扰下LVS负载均衡集群抗扰动算法。采用自适应神经模糊系统网络动态干扰监测模型构建网络信息鲁棒性评价模型及Linux嵌入式用户信任感知网络信息信任度评价,计算MAC层两个模糊概念之间的相似度。得到大功率干扰监测数学模型,假设干扰信号表现为一种动态随机噪声信号,实现对大功率干扰下的LVS网络的扰动容错方案设计,对簇节点的接收信号强度(RSSI)信息没有合理开发应用,在簇头生成过程中形成的帧没能实现自适应均衡处理,分析节点之间发射和接收信号的耦合效应,需要实现算法上的改进。仿真结果表明,该算法有效实现IP负载均衡和任务调度,延迟了网络生命周期,提高Linux虚拟服务器的抗扰动性能。 相似文献
3.
资源负载均衡是提高云计算资源调度效率的重要因素,为提高云计算中任务调度的效率,减少执行时间,针对传统的资源均衡算法在没有考虑到云计算环境下的资源节点安全性因素,复杂度高,效果不好的问题,提出一种引入安全性函数分形维特征重组的资源均衡算法。建立任务调度策略及资源均衡模型,构造任务调度所需要时间、费用、可靠性等方面的因素进行特征描述,对负载资源信息流的分形维信息特征提取,通过分层化状态重组,实现对资源负载的均衡处理,得到负载目标函数,提高任务处理效率。实验结果表明,该算法进行Cloud Sim平台下的负载云计算任务调度和负载资源均衡,能有效节省任务执行时间,降低计算开销,执行效率优越于其它算法。 相似文献
4.
Hadoop特有的集群任务,在真正运行之中,常会凸显不均衡态势下的负载情况。本文辨识了集群节点表现出来的执行特性、节点执行能力。建构在节点能力根基之上的多重任务,含有自适应调度这一配置方式。这类调度路径,按照节点特有的历程、现存负载状态、节点特性及关联的失效率,调整着各时段的运行总量。测验出来的数值表明,集群任务耗费的完成时段被显著缩减,节点荷载的总负荷均衡,资源调配适当。 相似文献
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研究海量信息存储过程中的数据库性能优化问题.假设数据库中存在海量信息,则数据库信息查询需要耗费大量的时间,无法满足当今社会的信息需求.因此,需要对数据库性能进行优化处理,提高数据库查询的效率.为此,提出了一种基于云计算的数据库性能优化方法.建立云计算数据关系模型,描述数据库中相关数据之间的联系,从而为数据查询提供依据.计算数据节点的负载状态,从而实现数据库中信息的快速查询.实验结果表明,这种算法能够有效提高数据库查询效率,取得了令人满意的效果. 相似文献
7.
在已实现的基于开源的LVS集群与GFS网络存储共享相结合的三层式体系结构的视频点播系统中,根据服务器实时负载信息动态调整权值,对已有的WLC调度算法进行优化,解决系统负载不均衡的问题,提高了系统的整体工作性能。 相似文献
8.
本文介绍一个Oracle数据库集群在电信增值领域的应用案例。通过数据切分和集群部署,解决海量用户信息数据的存储和访问的瓶颈问题。核心问题将围绕数据库分库分表的路由规则和集群负载均衡策略展开。 相似文献
9.
计算机产业集群潜在风险优化控制模型 总被引：1，自引：0，他引：1
《科技通报》2016,(2)
计算机产业集群中分布有大量的网络节点,由于产业集群链中节点的容错性能的差异性容易导致产业链出现风险,通过对计算机产业集群潜在风险优化控制,提高计算机产业集群网络的生存周期。传统方法采用分块聚类算法进行计算机产业集群潜在风险优化控制,随着风险指数随机增长,导致风险控制性能不好。提出一种基于集群网络容错机制提升和链路失效估计的计算机产业集群潜在风险优化控制模型。构建了计算机产业集群网络模型,然后对计算机产业集群网络中的潜在风险特征进行信息模型构建和数学分析,构建潜在风险评估目标函数,用集群网络容错机制提升和链路失效估计算法进行风险控制,进行计算机产业集群潜在风险控制改进。仿真结果表明,采用该模型通过潜在风险控制,能提高计算机产业集群网络的容错性能和生存周期方面的优越性能,实现了计算机产业集群潜在风险的转移控制,优化其转型升级路径。 相似文献
10.
基于链路同态解析的WSN路由选择算法 总被引：3，自引：0，他引：3
《科技通报》2015,(8)
通过优化无线传感器网络(WSN)的路由选择算法,实现负载均衡,节省WSN节点的能量开销。传统的路由选择算法使用基于汇聚节点随机链路分析的路由选择算法,控制网络中节点的密度实现路由选择,算法受到外界干扰较大,性能不好。提出一种基于链路同态解析的WSN路由选择算法。设计WSN节点的能量调度算法,提取网络传输的数据多路复用器输出端口的数据,找到经过最短路径数目最多的边并将它从网络中移除,采用能量剩余度同态解析模型,把WSN的能量节点变换到链路同态解析波束域中,实现WSN路由选择算法改进,实现WSN节点的能量调度,提高WSN的负载均衡能力。仿真结果表明,该算法能优化WSN的路由选择,节点的平均能量消耗最低,提高了WSN的可靠性和生存周期。 相似文献
11.
《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
12.
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
13.
《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
14.
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
15.
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
16.
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
17.
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
18.
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
19.
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
20.
Prof. SUN Changpu from the CAS Institute of Theoretical Physics coworkers from University of Basel in Switzerland have worked out a way - at least in theory - to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams is similar to the famous Stern-Gerlach effect whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states 《中国科学院院刊(英文版)》2008,22(1):23-23
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）. 相似文献