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无线传感器网络WSN的路由存活概率云计算模型的优化设计可以提高WSN网络的网络复杂和数据吞吐量,在WSN网络的路由发射功率能耗具有匹配衰减特性,路由存活概率优化困难。传统方法采用灰色马尔可夫链组合模型进行存活概率预测,云计算精度不高。提出一种基于不变波束形成的WSN路由存活概率云计算优化模型,进行WSN网络云计算路由链路模型的结构设计,在WSN网络中进行任务节点信息表征,采用能量剩余度向量概率密度优化分配算法进行能量分配,把WSN的能量节点信号从阵元域变换到波束域得到阵列域,采用空间协方差矩阵逆的高阶次幂来逼近WSN的数据传输信号模型,将旋转角度控制在半功率主瓣以内,由此得到了云计算模型下WSN路由节点数据传输模型。仿真实验表明,该算法能提高WSN路由的存活概率,从而提高了WSN的吞吐量和通信能力,路由概率寻优中抑制了在WSN网络的路由发射功率能耗的匹配衰减性,通过最小的能量开销实现路由分发速率和负载效益的最大化。 相似文献
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机会网络的混合路由优化设计可以有效降低冗余开销,提高数据传递成功率。传统方法采用链路代价评估和能量节省延迟容忍算法实现机会网络的路由设计,当在移动自组织网络中出现节点稀疏化调度下链路具有不对称性,降低了路由分配质量。提出一种基于改进的OLSRv2算法的链路不对称性预测控制机会网络混合路由优化算法,定义机会网络中混合置信因子概念,研究路由优化检验统计量的确定和判别系统的设计,通过OLSRv2算法引入了概率路由,在当前连通域的路由信息进行地址压缩得到最优传送概率值。仿真实验表明,采用该算法设计的机会网络路由进行网络通信,得到较小的控制开销,提高通信成功率,网络负载大幅降低。 相似文献
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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
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本文针对当前Ad Hoc网络路由的特点,在Ad Hoc路由优化算法基础上提出一种改进的蚁群算法.该算法首先将影响蚁群算法性能的参数作为遗传算法中的染色体,通过迭代找出最优的参数组合,然后对区域节点采用动态邻域分解的同时进行并行优化计算,最后将各子区域进行邻域全局连接得到最优解,该算法体现"分而治之"的思想.实验仿真结果表明,改进算法有效地提高了网络传输性能和通信效率,在性能上较基本蚁群算法有更大的优势. 相似文献
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无线传感器网络WSN发射功率的优化调度是决定WSN使用寿命和提高WSN性能的关键,WSN路由节点的在进行数据转发时会导致热点随机扩散,发射功率无法难以实现最大化。提出一种基于路由热点循迹修正的WSN发射功率调度算法。设计了WSN节点路由热点循迹数据传输模型,对发射功率消耗能量模型采用一个高斯衰减信道建模,采用直线反馈线性化补偿方式对路由热点的偏移轨迹进行超负荷状态评估,采用贪婪算法生成一条多分簇路由链,对路由循迹轨迹进行修正,得到WSN优化发射功率的调度递推公式,实现能耗最佳的功率优化调度。实验结果表明,采用该优化调度方法,在准确实现热点循迹修正,传输功率较传统方法稳定,波动较小,WSN可靠性和生存性增强。 相似文献
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提出一种基于高阶贝塞尔函数预测控制的路由空洞填补算法,进行移动网络电磁波通信路由协议设计,设计高阶贝塞尔函数特性及预测控制技术,采用高阶贝塞尔函数预测控制技术,通过移动网络电磁波通信网进行信息传输,产生不同的层次分类属性,实现对空洞填补算法改进。实验结果表明,算法能使路由空洞空间支路减少,边缘空间增益得到有效控制,降低误码率,提高移动网络电磁波通信系统的通信性能。 相似文献
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在异质同构自组网网络中,链路概率路由层具有随机分布特性,导致路由层数据完整性起伏不定。需要对概率路由层动态数据进行完整性检测,提高数据分发的Qo S服务质量。提出一种基于热点循迹的概率路由层动态数据完整性检测算法。进行异质同构自组网路概率路由层设计,通过热点循迹处理,取得数据的验证信息,输出数据信息动态更新策略,得到概率路由层数据动态更新和完整性确认模型。采用热点循迹随机分布预测控制计算动态数据分组转发控制开销,实现数据完整性检测改进。仿真实验结果表明,采用该算法进行异质同构自组网网络的链路概率路由层的动态数据完整性检测,有效降低数据丢包率,降低数据包的碰撞概率,网络负载大幅降低。算法在网络路由设计和通信中具有较好的应用性能。 相似文献
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《科技通报》2015,(2)
在集合PC机、无线传感器和Wi-Fi等通信网络进行无线传输网络组网中,功率消耗大,路径损耗多,需要进行无线传输网络组网交叉覆盖,以提高网络的吞吐性和抗干扰性。提出一种基于被动相干盲源分离算法的改进大功率无线传输网络组网交叉覆盖算法,构建大功率交叉网络模型,得到大功率交叉网络树状拓扑结构。采用隶属度调度控制Hough原理,对大功率交叉网络的分层信息数据进行分段处理,求解路由节点周期性的在一跳范围的检验统计量,在交叉网络跨层信息共享中,通过删除缓存数据得到跨层信息分组,实现交叉覆盖,实现无线传输网络组网交叉覆盖算法改进。通过仿真实验进行性能验证,得出采用该算法进行无线传输网络组网交叉覆盖,能改善输出信号质量,提高网络传输吞吐量,降低功耗损失。 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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《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