节能的无线传感器网络分簇路由协议的研究

LEACH协议是无线传感器网络中典型的分簇式路由协议,通过分析LEACH协议的优缺点,针对该协议的簇首选择机制进行改进,提出了LEACH-SERP的分区域簇首选择算法,该算法将整个网络分成若干个扇形区域,在每个扇形区域内独立地运行改进的LEACH协议,同时区域簇首与基站之间的通信由传统的单跳改为多跳,并进行了仿真分析。仿真结果表明,LEACH-SERP协议有效节约能量,平衡网络负载,延长网络生存时间。     

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.     

一种能量均衡的无线传感器网络分簇路由协议

由于无线传感器网络节点能量有限,为均衡无线传感器网络节点之间的能量消耗,提高整体网络的生命周期,针对LEACH协议中簇首选举时未考虑节点剩余能量因素、随机分簇等不足,提出了一种改进的LEACH协议.改进的LEACH协议在簇首选举时,以节点的剩余能量作为重要参考依据,优化节点担任簇首的概率.仿真结果表明,与传统的LEACH协议相比,改进的LEACH协议达到了能量消耗均衡的目标,从而延长了网络的生存寿命.     

一种基于能量预测的双簇首路由控制算法

在深入研究经典网络路由算法LEACH的基础上,提出了一种基于能量预测的双簇首(DCHBEF)路由控制算法。该算法利用改进的阈值产生式与节点剩余能量相关性并设计主、次簇首的选举和工作机制,解决了LEACH和SAHRC协议中的盲目分簇和簇内单簇首通信方式缺陷。仿真结果表明:DCHBEF算法比原有的LEACH和SAHRC算法有较好的节能性,并提高全网通信效率。     

LEACH节能路由协议的改进

传统的LEACH协议具有簇的位置无法控制、各节点成为簇首概率相同,当能量少的节点成为簇首时会消耗很多能量从而影响整个网络的工作、网络扩展性受限等缺点,基于传统LEACH协议的这些缺点,提出对LEACH的改进方法。在改进的LEACH协议中,综合考虑了节点当前剩余能量、簇首与节点和簇首与基站的距离以及簇头分布均匀性等情况,变单跳路由为多跳路由,根据网络规模合理确定簇首数,提出一种加权的阈值最优路由算法。改进的LEACH路由协议,可以明显地提高传感器网络的性能,有效地延长了网络生命周期。     

无线传感器网络分簇路由协议的改进研究

针对无线传感器网络(WSN)中分簇路由协议LEACH算法中簇首分配不均以及簇首与Sink节点直接通信问题进行研究,提出一种基于LEACH成簇思想的分簇路由协议。该算法基于节点剩余能耗和已担任簇首时间选举簇头。簇头间采用贪婪算法形成一条链,在该链中又选出一个簇头,将整个网络的数据融合后转发给基站。MatLab仿真结果显示,改进后的算法在均衡网络节点能耗和网络的生存时间上比LEACH算法有很大提高。     

基于Fuzzy C-Means聚类算法的改进LEACH协议

LEACH协议是一种被广泛应用到无线传感器网络中的路由算法。针对经典LEACH算法存在簇头节点空间分布不均匀和传感器节点能耗不均衡等缺点。提出了一种改进LEACH协议,新的路由算法首先利用Fuzzy C-Means聚类算法和节点位置信息将整个网络分割为多个簇;在每个簇中再利用考虑了节点剩余能量的LEACH算法完成单簇头的选举,以完成数据簇内收集和双跳传输。计算机仿真表明,改进的LEACH协议能均衡网络节点能耗,有效延长整个网络的生存周期。     

无线传感器网络分簇路由协议的改进研究

针对无线传感器网络（WSN）中分簇路由协议LEACH算法中簇首分配不均以及簇首与Sink节点直接通信问题进行研究．提出一种基于LEACH成簇思想的分簇路由协议。该算法基于节点剩余能耗和已担任簇首时间选举簇头。簇头间采用贪婪算法形成一条链,在该链中又选出一个簇头,将整个网络的数据融合后转发给基站。MatLab仿真结果显示,改进后的算法在均衡网络节点能耗和网络的生存时间上比LEACH算法有很大提高。     

基于能量和距离的分区域选择簇首WSNs路由算法

LEACH路由算法是能量有效、基于层次结构的经典路由算法,但它存在簇首选择不合理和能耗不均衡等缺点.针对这些缺点,提出了一种分区域分簇的路由改进算法A-LEACH.根据节点到基站的距离对节点进行区域划分,然后在特定区域用新的阈值来选择簇首,最后采用多跳的方式进行信息传输.分析和仿真结果表明:与经典路由算法LEACH相比,改进算法能够更有效延长网络的生命周期,均衡网络的能量分布和节省网路的能量.     

WSN中一种能量均衡的分簇路由协议的设计

无线传感器网络中,LEACH协议是典型的分簇路由协议.文章针对LEACH协议的缺点,结合PEGASIS协议的优点,从簇首选择、簇的形成、簇间路由等方面对LEACH协议进行了改进,设计了一种能量均衡的分簇路由协议EBLP,并进行了仿真分析.仿真结果表明,EBLP协议节约了能量,平衡了能量消耗,延长了无线传感器网络的生存时间.     

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)

正~~     

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