高效节能的无线传感器网络路由协议研究

现有的分簇式无线传感器网络路由协议中,簇大小通常是固定的.簇首间采用多跳通信的方式将数据传送至基站的过程中,靠近基站的簇首由于需要转发大量来自其它簇首的数据而负担过重,可能造成节点过早死亡.为了解决这种情况,提出一种非均匀分簇的多跳路由协议,根据与基站的距离建立大小不同的簇,靠近基站的簇规模小于远离基站的簇,靠近基站的簇首可以为数据转发预留能量.同时,在簇首选择机制上基于LEAcH做了一定的改进,通过综合考虑簇内平均能量、节点剩余能量等参数,有效避免了低能量节点被选为簇首.仿真实验结果表明,路由协议能有效地平衡簇首的能量消耗,延长网络的生存时间.     

无线传感器网络能量异构非均匀分簇路由协议

基于分簇的无线传感器网络路由协议,采用多跳路由方式传输数据至基站,容易造成靠近基站的节点转发大量数据而过早失效。另外,分簇协议通常假定网络节点是能量同构的,不能有效解决节点能量异构的问题。因此,从非均匀分簇的角度出发,结合局部竞争簇首机制,提出了一种基于能量异构的分簇协议（EHUC）。仿真结果表明该协议能够有效应用于能量异构的无线传感器网络,并延长网络的生命周期。     

一种分布式能量高效的WSNs非均匀分簇路由协议

针对无线传感器网络(WSNs)多跳通信方式中存在的"热区"问题,提出了一种分布式的、能量高效的非均匀分簇(DEEUC)路由协议。该协议将节点的剩余能量作为簇首选择的一个重要指标,候选簇首由上轮簇首根据簇内成员节点的剩余能量指定,候选簇首能否最终成簇首也是其能量竞争的结果。在DEEUC协议中,簇首以多跳的方式与基站进行通信并选择正向单位能耗最小的邻居簇首作为路由节点以节约能耗。仿真实验表明:DEEUC能较好地提高网络能效,延长网络生存时间。     

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。     

能量均衡的无线传感器网络非均匀分簇路由协议?

提出了一种能量高效均衡、非均匀分簇和簇间多跳路由有机结合的无线传感器网络分布式分簇路由协议DEBUC(distributed energy-balanced unequal clustering routing protocol).该协议采用基于时间的簇头竞争算法,广播时间取决于候选簇头的剩余能量和其邻居节点的剩余能量.同时,通过控制不同位置候选簇头的竞争范围,使得距离基站较近的簇的几何尺寸较小.这样,网络中不同位置节点之间的簇内和簇间通信能耗得以互相补偿.DEBUC 采用簇间多跳路由,根据节点剩余能量、簇内通信代价和簇间通信代价,每个簇头在邻居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,DEBUC能够有效地节约单个节点能量、均衡网络能耗、延长网络生存周期.     

WSN中基于分簇的改进路由协议

LEACH协议的非均匀分簇会造成网络节点能耗分布不均衡。为此,提出一种基于分簇的改进LEACH路由协议。根据节点剩余能量以及节点到基站的距离选举簇首,依据接收信号强度确定簇成员节点,并且成簇规模不得超过最大成员数。采用在簇首与基站之间建立多跳路由树的方法,向基站发送数据。仿真结果证明,改进协议能均衡网络负载,提高网络运行周期。     

一种基于树均匀分簇的WSNs节能路由协议

针对无线传感器网络(WSNs)典型分簇LEACH算法簇首分布不均和簇首与基站一跳通信能耗大的问题,提出一种基于树均匀分簇的节能路由协议(EUCR).基于节点接收信号强度与自身剩余能量的乘积及网络连通度选取簇首,计算簇首间的合理距离,使网络均匀分簇;基于跳数与簇首当前剩余能量构造簇间优化路由树.在OMNeT++中对EUC...     

能量均衡的无线传感器网络非均匀分簇路由协议

提出了一种能量高效均衡、非均匀分簇和簇间多跳路由有机结合的无线传感器网络分布式分簇路由协议DEBUC(distributed energy-balanced unequal clustering routing protocol).该协议采用基于时间的簇头竞争算法,广播时间取决于候选簇头的剩余能量和其邻居节点的剩余能量.同时,通过控制不同位置候选簇头的竞争范围,使得距离基站较近的簇的几何尺寸较小.这样,网络中不同位置节点之间的簇内和簇间通信能耗得以互相补偿.DEBUC采用簇间多跳路由,根据节点剩余能量、簇内通信代价和簇间通信代价,每个簇头在邻居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,DEBUC能够有效地节约单个节点能量、均衡网络能耗、延长网络生存周期.     

改进的WSN节能分簇多跳路由算法

LEACH算法是WSN中典型的单跳分簇路由算法,本文针对LEACH算法的缺点,提出了一种改进的节能分簇多跳路由算法.该算法采用层次分析法确定节点度数、节点间的通信距离、节点剩余能量和节点距基站的距离这四个因素的权值系数,在簇首选举中引入这四个因素,每一轮的簇首选举结束后,利用遗传算法寻找出一条遍历所有簇首节点和基站的最优路径,该算法实现了簇首以多跳通信方式向基站传输数据的功能.仿真结果表明,该算法在网络能耗、生存周期和能量均衡性方面均优于CECA、LEACH-GA和LEACH算法,达到了能量均衡和延长了网络生存周期的目的.     

基于最小生成树的非均匀分簇路由协议

针对无线传感器网络中利用分簇技术,簇首到Sink节点通信采用多跳路由方式容易引起"能量空洞"的问题,提出了基于最小生成树的非均匀分簇路由协议.该协议在簇首选举阶段,以节点剩余能量、节点度、节点能量消耗速度为权重计算簇首竞争等待时间,选用簇首竞争等待时间小的节点为簇首,以均衡能量;簇形成后,以剩余能量、簇间的距离和能量消耗为参数构建基于最小生成树的最优传输路径通过多跳方式将数据发送到Sink节点.仿真结果表明,该路由协议能有效均衡能耗,延长网络生命周期,延缓"能量空洞"的形成.     

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.     

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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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