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1.
针对传感网络中数据的差异性越来越大,数据属性差异会造成冲突,传感网络通讯耗时,网络节点效率较低等问题,提出了一种信息纠错校验的传感网络低错通信算法.运用改进的概率决策理论对数据进行融合差异出错概率判断,通过数据融合技术保证数据的最大化差异融合,保证能量耗尽的节点与出错节点的数据能够保证融合错误率最小,传感网络在低错状态下进行通信.实验证明,该方法能够大幅提高传感网络的通信效率,结果满意. 相似文献
2.
无线传感节点传输数据的时候存在能耗大、供应受限等问题,特别是传递多媒体图像信息的时候,节点承担的能量消耗更大。本文针对图像信息传递情况,在考虑图像本身具有的稀疏性基础上,利用网络节点图像数据稀疏系数构建了一种图像支撑集合稀疏模型。仿真实验证明,本文算法可以有效减少传感器节点在传输网络图像所需的数据传输,具有一定的推广价值。 相似文献
3.
根据社交网络信息传播多维度、多元化和基于人际关系的特点,构建一种基于用户相对传播能力的分层网络传播模型,对社交网络传播模型研究中缺少实例验证和用户层次分类的问题进行补充分析和证明。通过调查收集"平江火电厂重启事件"中公众对火电项目的态度变化数据,对政府相关宣传内容的传播过程、方式和效果进行归纳总结;采取K-Means方式对抽样的数据节点进行分类,构建以节点传播能力为划分标准的分层网络传播模型,分析模型中信息的传播路径、传播特征及权重关系。研究表明:(1)基于用户相对传播能力的分层网络传播模型更能真实地体现社交网络中信息传递的特点;(2)意见领袖层节点在信息传播过程中具有导向性作用,其网络影响程度约为普通群众的4倍(意见领袖节点的平均权重为2.6,普通群众节点的平均权重为0.6);(3)用户网络地位影响信息传递的效果,政府在提高公众支持度的问题上应该充分发挥意见领袖的作用,引导社会舆论。社会信息传播网络仍然是复杂网络研究中的难点,信息传递的方向、节点出度和入度都有待在未来的研究中进一步完善。 相似文献
4.
在传统的分簇算法中,网关节点不但需要完成对数据的基本感知,而且还要为相邻的分簇进行数据转发。因此一旦簇之间流量增大,预处理数据量将超过网关节点的负荷,该节点就会耗尽自己的相关资源,最终导致的结果就是,该节点成为整个网络的瓶颈节点。会降低整个传感网络稳定性,进而影响网络的吞吐量,缩短网络使用寿命。本文介绍一种在无线传感网络中加入移动节点的完全图算法,选择硬件配置高的节点作为网关节点,来处理簇与簇之间的通信,以此来增加传感网络的稳定性,延长网络的寿命。 相似文献
5.
非密集分布下传感网络节点选择优化算法研究 总被引：1，自引：0，他引：1
提出一种混沌差分进化和动态逃逸粒子群的节点选择优化算法,通过混沌序列的均匀遍历特性和差分进化算法的高效全局搜索能力,对传感网络中的节点能量进行分类搜索,采用Logistics混沌映射对节点进行优化分区处理,将混沌扰动量融入节点能量分区过程中,获取最佳能量节点,利用动态逃逸粒子群方法,运算无线传感网络最佳能量节点的最优位置,实现网络节点覆盖优化。仿真结果说明,所提算法可增强无线传感网络最优节点的聚类性能,具有更好的无线传感器网络动态节点选择性能,并且收敛速度快,运算耗时少。 相似文献
6.
《科技通报》2015,(10)
线性静态传感网络的生命周期受到网络中数据融合容错性能的影响,为了提高网络的生命周期,需要提高网络数据融合的容错性能,提高数据重构精度。传统方法采用基于传感器节点信誉度集分析的传感网络生命周期延展算法,无法有效去除簇头节点的数据冗余,功耗较大。提出一种基于极大似然估计法的线性静态传感网络的生命周期延展算法。进行线性静态传感网络模型构建,设置信标节点的个数和位置以及节点间通信半径,进行数据融合处理,根据极大似然法进行数据融合的冗余性分析,得到线性传感网络的生命周期延展的扰动方程,由此实现了极大似然生命周期延展算法改进。仿真结果表明,该算法的数据融合质量较好,使用定点迭代来加快算法的收敛性,节省了网络能量,延迟了网络生命周期。 相似文献
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8.
《科技通报》2017,(3)
物联网传感网络广泛应用在环境监测和模式识别等领域,物联网传感网络的路由协议通过多跳汇聚树路由网络进行组网,随着节点数目的增多容易出现链路故障,需要进行路由修复和改进设计。提出一种基于链信息头抽取和信息源定位的物联网传感器网络路由改进设计方法。构建了物联网下传感器网络的组网和路由探测模型,采用链路信息簇头节点抽取和信息源定位方法进行链路路由信息数据聚集,采用预加重方法广播竞选簇头节点的能量损失,通过双向链路估计得到路由节点的数据传输协议,采用链路节点能量和Sink节点距离分层方法实现路由优化设计。仿真结果表明,采用该方法进行物联网传感网络的路由优化设计,提高了链路信息收发和数据传输的可靠性和吞吐量,性能优越。 相似文献
9.
无线传感网络作为新兴的测控网络技术,是能够自主实现数据采集、融合和传输应用的智能网络应用系统。无线传感网络是逻辑上的信息世界与真实的物理世界紧密结合,从而真正实现”普适计算”模式。目前在节点硬件平台的研究比较少,很多采用国外产品,因此首先对国内外的无线传感节点进行分析,研制了一款无线控制节点,结合无线采集节点组成了一个小型无线传感网络测控系统。实现了采集节点与上住机的通讯,并使用上位机软件对无线数据的传输特性进行了分析和研究,最后通过无线传感网络测控系统对温室的温湿度实施了控制,控制效果良好。 相似文献
10.
对无线传感网络节点异常行为检测与信誉评测标准模糊单一,容易导致分发延迟、丢包以及被恶意攻击等情况的发生。提出一种基于随机性和模糊性云计算定量分析的无线传感网络通信链路优化策略,对每个临近区域内任意相邻的传感器节点进行随机性和模糊性的云计算定量分析,对节点的彼此行为进行监控,计算各传输节点在数据传输中自身对对方的直接信任值和间接信任值,根据合成法则产生综合信任值,优化对数据通信进程。仿真实验表明,优化策略能快速有效识别有用数据和恶意数据,提升通信效率,节省无线传感网络节点能耗,保证了大规模数据传输和融合的安全性和准确性。 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.
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
16.
《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
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.
《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献