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1.
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
2.
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
3.
为了增强无线传感网络(WSN)的自适应性,降低WSN功耗,需要进行配网路由修复。传统的路由修复算法采用能量感知模型,设置负载平衡的CTP路由协议估算剩余能量,算法没有考虑路由最大角度的负载平衡问题,路由修复性能不好。提出一种基于负载-功耗联合特征测试的WSN配网路由修复算法,设计了基于ICTP协议的WSN网络模型框架,综合考虑簇头的剩余能量及其与Sink的距离对它的生命周期的影响,进行路由选择设计,采用负载-功耗联合特征测试方法,实现WSN配网路由修复改进。实验结果表明,该算法进行WSN路由修复设计,节点剩余能量方差一直维持在最低,有效地均衡了网络负载,平衡了网络能量消耗,节点生存性较大,提高能量的有效利用率。 相似文献
4.
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
5.
车载自组网WSN无线传感网络的接收/发射功率的无偏均衡设计,可以提高网络节点寿命,保证系统的稳定性,提高车载自组网的通信能力和网络连接率。传统方法采用的固定步长加权的滤波设计算法进行功率均衡设计,导致车载自组网的相邻节点功率均衡偏差,提出一种基于无偏均衡和相位谱拟合的车载自组网中功率增益优化算法,进行无偏均衡的车载自组网中网络连接率优化设计,确定节点一跳范围内的邻居节点,实现功率谱的估计,在功率均衡设计中,进行可变步长滤波设计,反映了信道幅值、时间和频率之间关系,对相位谱做最小二乘拟合求斜率,实现WSN可变步长滤波接收/发射功率无偏均衡算法改进。研究结果表明,该算法实现了接收/发射功率的无偏均衡,网传输距离提高,具有较大的功率增益,网络连接率较传统方法提高,展示了优越的应用性能。 相似文献
6.
无线传感器网络(WSN)在复杂应用环境下的双选信道特征配准算法研究,是对WSN数据管理的关键技术,WSN在数据发送中要经历时间和频率的双选择性衰落,为了在接收端被正确地接收,需要进行特征配准设计。传统方法采用普勒域单信道配准方法,特征配准效果不好。提出一种基于时延-多普勒域的时间和频率双选信道特征配准算法,满足复杂应用环境下的WSN数据管理需求。在线自适应调整信道配准控制误差,动态实时捕获信道传输数据,实现节点自适应优化分布,通过信道模型构建,对WSN进行时延-多普勒域表征,采用双选信道估计方法实现特征配准。仿真结果表明,该算法在复杂应用环境下,根据不同的调制信号,在不同带内信噪比下能实现对WSN的双选信道特征配准,准确率高于传统算法,抗噪性能较好,提高WSN的数据管理和调度能力,展示了本文算法的优越性能。 相似文献
7.
实现功率增益是电力GIS配网的重要目的,传统的电力GIS配网中基于电网负载传输速率和节点发射功率算法进行调度控制,控制链路之间产生差拍分离,负载均衡效果不好,功率增益不明显,影响电力GIS配网和调度性能。提出一种基于PID神经网络控制的GIS配网调度方案,设计GIS配网PID无差拍控制算法,构建GIS配网节点发射功率博弈的纳什均衡博弈模型,控制方程中基于纳什均衡解求解簇首节点的最佳发射功率,实现GIS配网中所有簇首节点有最佳发射功率。仿真结果表明该算法具有良好的收敛性,簇首节点的发射功率有较高增益,降低了节点能耗,提高GIS配网性能。 相似文献
8.
《科技通报》2015,(8)
对卫星通信信道传感器网络的空间节点资源优化控制可以提高卫星通信网络资源的利用率,节省卫星通信网络开销,提高卫星通信传输吞吐能力。提出一种基于稀疏分布的空间节点资源循环迭代控制算法,通过构建空间节点资源的稀疏化控制矩阵,得到最大偏离调度控制量,采用循环迭代思想实现对空间节点资源的循环迭代控制。实现WSN空间节点资源控制模型的设计,构建WSN空间资源任务节点信息表征,得到WSN网络空间状态的最小正特征带状的连接权值,实现对卫星通信WSN网络的空间节点资源循环迭代控制算法的改进。仿真实验结果表明,该算法能提高卫星通信网络资源的利用率,节省卫星通信网络开销,WSN通信节点具有较好的数据吞吐性能,资源分配和控制效果达到最佳状态,展示了其优越性能。 相似文献
9.
《科技通报》2016,(8)
在物联网环境下无线传感器路由节点的准确探测实现节点的定位识别,将在传感器节点的故障监测和目标识别等领域具有较好的应用价值。传统的传感器路由探测算法采用源结点追踪定位方法实现传感器路由探测,当源节点受到外界电磁场干扰时,路由探测准确性不好。提出一种基于最短路径搜索的物联网环境下无线传感器路由探测算法。构建了物联网环境下的传感器网络分布结构模型,进行传感器路由信息的量化分析,采用最短路径搜索方法进行路由传输信息的跟踪探测,采用线性阵列结构部署路由节点,能实现路由节点探测和定位的最短路径搜索。仿真结果表明,采用该算法进行物联网环境下传感器路由探测提高了传感器节点的生存概率,路由探测能量消耗较小,路由节点定位准确,提高了目标节点的识别和监测能力。 相似文献
10.
《科技通报》2015,(10)
设计高速网络流路由修复算法,提高网络的生命周期,降低路由节点能耗。传统的路由修复算法采用阈值分割路由冲突分解算法,采用阈值分割判断实现路由修复,无法有效满足高速网络流路由修复的应用环境。提出一种基于断点损耗预测的高速网络流路由修复方法。计算通信节点的衰减性能,绘制出符合高速移动环境移动节点衰减曲线,根据欧氏距离公式计算出随机分布的路由节点的路径链接的稳定性,对多角度系数进行修订,采用断点损耗预测方法,进行功耗损失修订,实现路由修复。仿真实验表明,该算法实现高速网络流路由修复。有效地控制簇头的数量和分布、节约能量、均衡网络负载,提高了高速网络流路由的生命周期,单个节点能耗大幅降低,在高速移动大规模网络流维护和路由控制优化中具有较好的应用价值。 相似文献
11.
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
12.
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
13.
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
14.
《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
15.
《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
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.
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