一种节能的无线传感器网络路由协议的设计与实现

在无线传感器网络的路由协议中,基于簇的路由协议在拓扑管理、能量利用、数据融合等方面具有优势。本文针对目前已有协议能量消耗大、网络寿命短等问题,提出了一种能量感知的基于分布式簇算法的无线传感器网络协议EA-HEED。此协议改进了分布式的簇头选举算法,分配时分复用时隙并在簇头节点建立一棵路由树,从而提高簇头选举效率;设计了休眠冗余节点的簇内活动节点调度算法,减少能耗;采用考虑节点能量和节点与基站距离的簇头节点组织路由树方法、最小化网络开销以及能量负载平衡方法,优化路由协议,有效延长网络寿命。仿真结果表明,与LEACH和HEED协议相比,EAHEED协议可以进一步延长网络寿命。     

一种新的基于LEACH的WSN路由算法

研究无线传感器网络路由算法,无线传感器网络由能量有限的节点组成,因此高效节能的路由算法是无线传感器网络组网的基础.针对低功耗自适应分簇(LEACH)路由算法存在簇首节点选择不合理以及簇首节点与基站在远距离通信过程中能量消耗大的不足,提出了一种改进的LEACH路由算法.改进的算法在簇建立阶段的簇首选举过程中,引入节点剩余能量因素,且进行均匀分簇,有效地降低剩余能量较小和位置不佳节点成为簇首的可能性,均衡了网络的能量消耗,在簇稳定工作阶段,节点间的数据传输采用单跳和多跳相结合的通信方式,从而降低网络能耗.仿真结果表明,与传统的LEACH算法相比,改进的LEACH算法能量均衡性更好,并显著地延长了网络的存活时间.     

基于分簇机制的ZigBee混合路由能量优化算法

针对ZigBee路由协议没有很好结合AODVjr(Ad hoc On-Demand Distance Vector Routing Junior)和Cluster-Tree算法的问题,从网络能量优化的角度出发,文中设计了一种基于分簇机制的ZigBee混合路由算法——CLZBR算法,簇间采用AODVjr算法,簇内采用Cluster-Tree算法,并通过计算目的节点的父节点地址等方法,减少网络中冗余的RREQ(Route Request)分组,降低能量消耗;同时为了避免簇首由于能量过度消耗而成为失效节点,该算法提出备用节点的概念,当簇首能量过低时代替簇首以保证网络的稳定性.仿真结果表明,CLZBR算法相对ZigBee混合路由算法在包投递率、路由开销百分比和网络剩余能量百分比方面都有明显改善.     

改进的ZigBee网状网络路由算法研究

针对ZigBee网络中AODVjr路由算法存在节点死亡率高、网络能耗大的问题,结合节点的存储结构、能量和链路质量特点,提出一种改进的ZigBee网状网络路由算法F-AODVjr。在路由发现之前,利用路由节点自动维护的邻居表寻找目的节点,以降低因路由请求(RREQ)分组寻址目的节点导致的能量消耗。在路由发现阶段,通过改进AODVjr路由算法的最短路径寻址思想,设计含有路由跳数、节点剩余能量和链路质量的路由算法,寻找具有最低路由成本的优化路径。仿真结果表明,F-AODVjr路由算法可以有效降低网络整体能量消耗,提高节点生存率及数据分组成功投递率。     

能量高效的ZigBee网络改进路由策略

在分析现有ZigBee网络路由策略的基础上,以节省网络能耗和均衡网络负载为目的,提出一种能量高效的改进路由策略。该策略分别对ZigBee网络的簇树拓扑结构以及基于簇树算法和AODVjr算法的ZBR路由策略进行改进。改进后的路由策略在尽量减少路由开销的同时充分考虑对能量偏低节点的保护。仿真实验验证,改进策略能有效减少网络能耗,均衡网络负载,最大化网络的生存时间。     

能量高效的ZigBee网络改进路由策略

在分析现有ZigBee网络路由策略的基础上,以节省网络能耗和均衡网络负载为目的,提出一种能量高效的改进路由策略。该策略分别对ZigBee网络的簇树拓扑结构以及基于簇树算法和AODVjr算法的ZBR路由策略进行改进。改进后的路由策略在尽量减少路由开销的同时充分考虑对能量偏低节点的保护。仿真实验验证,改进策略能有效减少网络能耗,均衡网络负载,最大化网络的生存时间。     

一种ZigBee路由算法的分析与改进

无线传感器网络中,节点能量受限性使得传统的路由协议不能满足需求。在设计适合无线传感器网络的路由协议时,应首先考虑能量因素,尽量减少节点之间的通信量。文中分析了无线传感器网络的特点和ZigBee协议中的austertree路由算法,对其中的分簇方法进行了研究,在此算法的基础上,利用节点的深度信息对算法进行了简化,并考虑了能量均衡利用的问题,以实现延长网络生存周期的目的。在同等实验条件下,仿真结果表明改进后的算法在延长网络生存期方面比LEACH有很大提高。     

无线传感器网络路由算法改进及仿真研究

由于无线传感器能量消耗影响网络的寿命,传感器节点的能量无法更新且种能量受限,传统路由算法忽略簇头剩余能量情况,使剩余能量低的节点成为簇头而过早死亡,导致整个网络能量不均衡,网络生存时间过短。为了有效延长网络生存时间,提出一种改进的LEACH路由算法。在簇头选择阶段,采用剩余能量的簇头节点优先选择机制,避免剩余能量低的节点成为簇头,然后在数据传输阶段,用单跳和多跳的混合传输模式,使整个网络能量尽量均衡。仿真结果表明,相对于传统LEACH路由算法,改进算法更加均衡了网络中各节点的能量消耗,有效地防止剩余能量低的节点成为簇头,可延长整个网络的生存寿命。     

基于优化簇半径的WSNs非均匀分簇路由

为了有效解决无线传感器网络分簇路由协议中,靠近SINK节点的簇头因特发大量数据而过早耗尽能量,提出了一种优化簇半径的非均匀分簇路由协议(UCOR),其核心思想是通过优化簇半径对无线传感器网络进行合理分簇,使靠近SINK节点的簇规模小于远离SINK节点的簇.仿真实验结果表明,与EEUC和LEACH等路由协议相比UCOR路由协议有效地均衡了节点能量消耗,显著地延长了网络生命周期.     

能量高效的无线传感器网络路由协议

针对目前无线传感器网络分簇路由协议存在的节点能耗不均衡的问题,提出一种基于分簇思想的能量高效的多跳路由协议(EEMR)。该协议首先基于节点临近度将网络划分成簇,采用簇首自适应轮转模式优化簇内节点通信的能量消耗,以高剩余能量短路径向心角的适应度路由算法均衡簇间通信负载和能量消耗,有效避免多跳路由中出现的能量消耗不均衡问题。仿真结果表明,EEMR协议能有效均衡网络内节点的能量消耗,显著延长无线传感器网络的生命期并提高网络能量利用率。     

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.     

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.     

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.     

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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