基于路径宽度的Zigbee网络路由算法优化

针对AODVjr算法在路由查找过程中的盲目性导致网络能量利用率不高的问题,提出一种基于路径宽度的W-AODVjr算法。该算法通过在源节点与目的节点之间形成一个环状封闭路由查找区域,并采用指数查找的方式确认最优路径宽度。通过源节点选取路径中节点剩余能量最大的节点,以此作为路由的方法来最大限度保护低能量节点。NS2仿真结果表明,W-AODVjr算法能有效保证数据包发送的成功率,与AODVjr算法相比,网络能量利用率提升8%,生命周期延长约为12%,在Zigbee网络中W-AODVjr算法更具优越性。     

基于遗传算法的无线传感器网络能耗优化

为了延长无线传感网络的使用寿命,提出了一种优化传感网络路由的遗传算法。该算法通过分析节点发送功率变化下的链路流量约束,链路最大传输效率约束,节点能耗约束等条件。感知路由从数据传输的能量消耗量出发,讨论最优能量消耗路径,提高节点能量利用率,延长网络生存期。其基本实现是根据节点的剩余能量和传输路径上的能量消耗来选择路由路径。仿真实验表明,该算法可以平衡节点能耗和邻节点使用数量,延长网络的生存寿命。     

基于改进蚁群优化算法的无线传感器网络路由研究

无线传感器网络为能量受限系统,为了促使网络节点能量消耗相对均衡,将蚁群优化(ACO)算法应用于无线传感器网络的路由选择,提出一种基于能量均衡的无线传感器网络路由算法。该算法将节点能量作为转移概率规则启发因子,通过计算转移概率和适应度值找到最优路径。仿真结果表明:该算法可以显著减低网络总能耗,从而延长无线传感器网络的生命周期。     

基于最小生成树的传感器网络能量均衡组播协议

为了均衡无线传感器网络中节点的能量消耗,进而达到延长网络生命周期的目的,提出一种基于最小生成树形成虚拟主干树的能量均衡的组播路由算法.该算法在选择转发节点的过程中,综合考虑前向转发区域内的节点的位置及能量信息,并引入修正因子及路径封锁技术.仿真实验表明,该算法能够有效的均衡传感器节点的能量消耗,延长网络的生命周期.     

依托路由规则的自适应能量优化分簇无线传感器网络路由算法

针对分簇无线传感器网络中节点能量负载不均衡导致簇头在任务较多的情况下过早死亡,以及路由能量损耗较大等问题,提出一种自适应能量优化分簇的路由算法。在簇头选举和竞争半径的计算上通过权衡系数充分考虑了竞选节点的剩余能量与距离情况,延长了簇头的生命周期。以路由规则的形式来制定簇头间转发数据是采用单跳路由还是多跳路由,在保证簇头不会过早死亡的情况下最大化减少路由的能量损耗。实验仿真结果表明,自适应能量优化分簇的路由算法可以延长网络节点的生命周期,减少能量损耗。     

基于通信代价的Zigbee网状网络路由选择算法

针对Zigbee网状网络AODVjr路由算法在路由发现过程中引起的节点能耗不均衡问题,提出了一种通过有效选择转发节点,动态建立通信路径的路由选择算法.该算法在定义通信代价函数的基础上,通过限定邻居前区集合来确定待选节点集,并综合考虑待选节点的剩余能量以及待选节点转发数据至下一跳的能量损耗,选择具有最小通信代价的节点转发数据,尽可能的减小节点在路由发现过程中所引起的不必要的能量损耗.仿真结果表明,该算法能够有效地均衡节点能量、降低网络能耗、延长网络生命周期.     

基于蚁群优化的WSN功率自适应路由算法

为节省节点能量开销,延长无线传感器网络(WSN)的生命周期,在研究蚁群优化算法的基础上,提出一种基于蚁群优化的功率自适应路由算法。在蚂蚁寻路时考虑节点的传输方向、剩余能量和节点间距离。寻找到一条最优路径后,根据相邻两节点间的距离调整节点的发射功率,避免功率过大造成能量浪费。仿真实验结果表明,在节点非均匀分布的情况下,该算法能够有效节省网络开销,延长网络生命周期。     

一种基于权重的DSR路由改进算法

提出了一种基于权重的DSR路由改进算法.该算法利用跳数与能量参数构造一个路由权重函数,选择权值最大的路由作为源节点到目的节点之间的路径,以提高整个网络的生命周期.仿真结果表明,该算法可以有效地节省网络能量,延长网络生命,同时减小了网络的端到端延时,提高了网络的性能.     

基于能量感知与能量均衡的ZigBee网络树路由算法研究

针对传统ZigBee网络树路由算法存在节点能量消耗大的问题,提出了一种改进的基于能量感知和能量均衡的ZigBee网络树路由算法。该算法将邻居节点考虑在内,在确定路由的下一跳节点时,在更大的搜索范围内寻找路由开销最小的网络路径来降低功耗,同时根据路径上节点的剩余能量选择累积路径损耗和路径能量消耗较低的路径进行数据发送,从而降低了网络的总体能耗。仿真结果表明,该算法能避开能量过低的节点进行数据传输,实现了节点的能量均衡,延长了节点的生存时间。     

一种带有能量自补给节点的异构传感器网络分簇路由算法

针对现有无线传感器网络分簇路由算法的网络生命周期短、能量消耗不均衡等问题,结合节点的能量采集技术,提出了一种带有能量自补给节点的异构传感器网络分簇路由算法。考虑到实际环境中节点能量补给不稳定,根据节点的剩余能量和当前能量自补给状态,设计了能量均衡的簇头选举机制和簇间多跳机制。仿真结果表明,在延长网络生命周期和均衡全网能量消耗方面,该算法优于采用相同能量补给规律的传统分簇路由算法(LEACH算法和SEP算法)和其他基于能量自补给的分簇路由算法(PHC算法和EBCS算法)。     

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