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中基于非均匀簇的混合多跳路由协议*

为节省数据传输过程中消耗的能量,均衡网络节点间的能耗,提出一种基于非均匀簇的混合多跳路由协议。在无线传感器网络数据传输阶段,源簇头节点通过转发权值函数选择数据转发的中继节点,转发权值由用于降低链路通信代价的距离因子和减少剩余能量较少的簇头节点成为中继节点的概率惩罚因子共同决定,达到均衡网络能耗的目的。通过NS2仿真实验验证了算法的有效性,能够很好地均衡节点负载和提高能量利用率。     

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.     

无线传感器网络的分布式竞争路由算法

在WSNs体系结构中,路由算法是网络层的关键,分簇技术在路由算法中可提高WSNs的扩展性;提出一种竞争簇头,非均匀分簇和多跳路由相结合的WSNs分布式竞争路由算法(DSA);它的核心是构建一个高效的非均匀分簇算法,通过竞争的方式候选簇头,靠近基站的簇头为簇间的数据转发预留能量,根据节点的剩余能量、簇内和簇间通信代价,每个簇头在邻居簇头集中用贪心法确定中继节点;仿真表明,DSA算法能有效平衡了簇头的能耗、均衡了网络能耗、显著延长网络生存周期.     

基于位置信息的双簇头路由算法

针对无线传感器网络(WSN)的高能效路由选择问题,在混合式能量均衡分簇(HEED)算法基础上提出一种基于位置信息的低能耗双簇头多跳路由算法(HEED-EELD)。假设网络中所有节点都具有位置感知能力,网络根据最佳单跳距离划分层级,节点根据自身位置确定所在层级。簇内选举产生双簇头,分担单一簇头的工作,均衡簇头能耗。在簇间多跳路由中,簇头根据位置、距离和剩余能量的代价函数选择最优路由。Matlab仿真结果表明,与低功耗自适应分簇(LEACH)算法、HEED算法相比,提出的HEED-EELD在网络寿命、能量效率、能耗均衡等性能方面具有明显的性能增益。     

一种分布式能量有效的无线传感器网络分簇路由协议

提出了一种分布式能量有效的无线传感器网络分簇路由协议DEEC(Distributed Energy-efficient Clustering Algorithm)。该协议采用基于时间的簇首选择算法,广播时间取决于自身剩余能量和其邻居节点的剩余能量。在数据传输阶段,采用簇内单跳与簇间多跳相结合的方式,引入权值函数优化簇首中继节点的选择。仿真实验结果表明,与LEACH,PEGASIS协议相比,DEEC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。     

一种压缩感知的异构传感网络分簇路由算法

分簇路由算法对用于事件监测的无线传感器网络具有较好的节能性,压缩算法可以降低节点传输的数据量,但增加了分簇簇首的计算能耗和汇聚中心的时间复杂度,而由高端节点担任簇首可以实现能量均衡并提升服务性能.设计了一种适应多级能量异构网络的压缩感知算法,簇首当选的概率由异构节点的剩余能量大小确定,簇首负责收集簇内成员节点的数据,进行稀疏、压缩,减少传输的数据量,簇间路由采用多跳最小的代价函数传输,而汇聚中心通过重构算法将少量信息解码得出原始数据.仿真结果表明,该算法能有效解码目标源,减少死亡节点数量,并且能均衡异构节点的能耗.     

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...     

WSN中能耗均衡的非均匀分簇路由算法

针对无线传感器网络中能耗不均衡、生命周期短的问题,提出WSN中能耗均衡的非均匀分簇路由算法。通过改进的K均值算法进行非均匀分簇,引入双簇首减轻簇首通信压力;利用基尼系数衡量簇内节点的能耗均衡性,以动态权值调整影响副簇首竞选的因素;簇间采用单跳和多跳相结合的传输方式,将剩余能量、传输距离、转发次数和节点数作为中继节点选择的依据,均衡簇间传输能耗。仿真结果表明,相比LEACH和EBRAA算法,提出算法能有效均衡节点能耗,延长生命周期和提高吞吐量。     

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