基于非均匀分簇和信息熵的无线传感网络路由算法

针对无线传感网络分簇算法中能量分布不均衡导致的“热区”问题,提出一种基于非均匀分簇和信息熵的路由算法。在簇头选举和竞争半径计算过程中综合考虑节点能量、节点密度和节点距基站距离,均衡簇头能耗以延长生存时间。采用簇间单跳多跳混合通信的路由规则,减少簇间通信能耗。对节点信息熵进行数据融合,引入融合权重系数减小数据融合的不确定性,提高数据融合效率。仿真结果表明,与LEACH、EEUC和EBUCA相比,该算法能够有效均衡网络能耗,延长网络生命周期。     

基于博弈论能耗均衡的WSN非均匀分簇路由协议

在无线传感器网络(WSN)的分簇路由算法中,节点间能耗不均容易引发 “能量空洞”现象,影响整个网络的性能。针对这个问题,提出了一种基于博弈论能耗均衡的非均匀分簇路由(GBUC)算法。该算法在分簇阶段,采用非均匀分簇结构,簇的半径由簇头到汇聚节点的距离和剩余能量共同决定,通过调节簇头在簇内通信的能耗和转发数据的能耗来达到能耗的均衡;在簇间通信阶段,通过建立一个以节点剩余能量和链路可靠度为效益函数的博弈模型,利用其纳什均衡的解来寻找联合能耗均衡、链路可靠性的最优传输路径,从而提高网络性能。仿真结果表明:与能量高效的非均匀分簇(EEUC)算法和非均匀分簇节能路由(UCEER)算法相比,GBUC算法在均衡节点能耗、延长网络生命周期等性能方面有显著的提高。     

基于能量迭代的无线传感器网络非均匀分簇路由算法

能量空洞是影响无线传感器网络性能的关键问题之一,据此提出了一种基于能量迭代的非均匀分簇路由算法。该算法首先在簇头选举时通过减少迭代次数,降低能量消耗,同时综合考虑节点能耗速度、节点到汇聚节点的距离等因素,选出最优簇头;其次,考虑到节点到汇聚节点距离和节点密度对网络生命周期的影响,提出了非均匀分簇算法,实现网络能耗均衡的目的。仿真实验表明,当最大簇半径为50m ,选举因素所占权重为0.4 ,簇半径调节系数为0.7时,本算法达到最优,与LEACH-E和LEACH相比,网络生命周期分别延长125%和136%,同时有效避免了能量空洞现象的产生。     

基于学习自动机的无线传感网能量均衡分簇算法

优化簇首选择、均衡节点能量负载以延长网络存活时间,一直是无线传感器网络分簇协议研究的重点。针对无线传感器网络节点随机分布的情况,在基于学习自动机(Learning Automata, LA)的ICLA算法基础上,提出一种兼顾节点密度的能耗均衡分簇算法。在簇头选举方面,综合考虑节点剩余能量和节点密度,利用学习自动机与周围环境进行信息交互和动作奖惩,选择出相对较优的簇头;根据簇首与基站距离和其节点密度构造大小非均匀的簇,实现不同位置不同网络疏密程度下簇内和簇间能耗互补均衡;构造了基于簇首剩余能量、簇内节点密度和传输距离的评价函数,并运用贪婪算法选择出最优中转簇首进行多跳传输。仿真实验结果表明,该算法能选择出更为合理的簇头,有效地均衡网络能量负载,延长网络生存时间。     

高效节能的WSN非均匀分簇节点调度算法研究

针对目前无线传感器网络分簇算法中存在的节点能量消耗不均衡,大量节点工作导致信息冗余和能量浪费等问题,提出一种高效节能的WSN非均匀分簇节点调度算法EEBUC（Energy-Efficient and Balanced Unequal Clustering Nodes Scheduling）。该算法在簇的形成阶段,考虑候选簇首离汇聚点的距离、所在区域的节点密度和节点能量形成非均匀的竞争范围,构造大小不等的簇,平衡簇内和簇间的通信能耗;同时结合调度簇内冗余节点方法,减少网络中每轮工作节点数量,提高网络能量利用率。利用OMNET++仿真软件进行仿真,实验结果表明,EEBUC算法能有效节约网络能量,均衡节点能耗,比LEACH 协议和EEUC协议分别延长网络寿命203%和50%。     

基于细胞膜优化算法的WSN分簇协议研究

针对无线传感器网络能量受约束的问题,为实现节点均衡能耗,平衡网络簇头分布,并最大限度地延长网络寿命,提出一种基于细胞膜优化算法的无线传感器网络能量均衡分簇协议。细胞膜优化算法具有良好的全局寻优和快速收敛能力,通过浓度与能量因素对节点进行划分,并结合距离因素完成全局均衡分簇,能够解决传感器网络中簇头分布不均匀、全局能耗不均衡等问题。实验结果表明,该协议具有对无线传感器网络进行快速全局均衡分簇的能力,且与LEACH算法和LEAH-C算法相比,在均衡节点能耗和延长网络生存周期等方面具有更好的性能。     

一种基于节点位置和密度的非均匀分簇路由算法

分析了现有分簇路由算法,提出了基于节点位置和密度的非均匀分簇路由算法。簇头选举阶段,考虑了节点的剩余能量,并引入竞争机制进行簇头选择;成簇阶段,综合考虑节点与基站的距离、节点密度以进行非均匀分簇,达到节点能耗均衡的效果,同时解决路由热区问题;簇间路由阶段,通过设立通信簇头节点,使簇间数据转发任务从簇头中分离,簇头节点只负责簇内的数据收集和融合,而通信簇头节点负责簇间数据传输,减少了簇头的能量消耗。实验结果表明,改进后的路由算法能够有效地均衡网络负载,并显著地延长网络的生命周期。     

改进的非均匀分簇无线传感器网络路由算法

针对无线传感器网络中分簇算法求全局最值问题和非均匀分簇算法能量消耗不均衡问题,提出一种新的分簇算法。该算法首先采用泛洪树算法来求得网络最值,并用它来计算节点的竞争半径,然后用非均匀分簇的思想来构建大小不等的簇。当选取簇头节点后,通过计算每个簇头的概率来寻找下一跳簇头,当每个簇头节点选择最佳下一跳路径后,簇间通信可以建立一条最佳路径。仿真结果表明,该算法在能量损耗和均衡能耗都有显著的提高,最终延长了网络的生存周期。     

改进的无线传感器网络非均匀分簇路由算法

针对无线传感器网络中不均匀分簇引起能量空洞的问题,提出了改进的无线传感器网络非均匀分簇路由算法。该算法先根据节点剩余能量、节点到基站的距离、节点“度”和节点到簇头的距离等因素选举簇头;没有成为簇头的节点选择加入到距离最近的簇头所在的簇中,从而将整个网络划分为大小不等的簇;然后簇头再根据簇头剩余能量、簇头到基站的距离构造基于最小生成树的最优传输路径;通过簇内节点单跳、树内簇头多跳通信的方式将数据最终传输到基站。仿真结果表明,该路由算法能有效节约能量和均衡节点能耗,从而延长网络的生命周期。     

基于PSO的无线传感器网络非均匀分簇路由协议

提出并分析了一种能量均衡的集中式非均匀分簇路由协议EBUCP(energy-balanced unequal clusteringprotocol),本协议采用非均匀分簇和簇间多跳路由有机结合的方式。应用PSO算法,EBUCP选择一组最佳节点担任簇头并将网络划分为大小不等的簇,不仅最小化簇头和簇成员的距离以减小簇内通信能耗,同时使得距离基站较近的簇具有较小的几何尺寸来平衡不同位置簇头的能耗。EBUCP根据节点剩余能量和节点与基站距离确定簇间多跳路由,每个簇头在所有簇头集合中运用贪婪算法选择其中继节点。仿真实验结果表明,与LEACH和PSO-C协议比较,EBUCP的网络生存周期明显延长,能耗均衡性能更好。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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