6LoWPAN无线传感器网络有状态地址配置方案*

提出一种基于分布式的6LoWPAN无线传感器网络有状态地址配置方案,其每个传感器节点都具有分配地址的权力且地址分配空间具有唯一性,从而将地址分配任务均匀地分布到每个传感器节点,实现了多个传感器节点的同时配置,提高了地址分配效率;同时,节点申请地址的控制信息的传输范围均控制在一跳范围内,降低了地址配置功耗,缩短了地址配置时间,延长了网络寿命。对所提方案与MANETConf、Strong DAD及LISAA的地址配置代价及地址配置延迟时间等性能参数进行了比较分析,分析结果验证了此方案的可行性和高效性。     

基于簇的全IP无线传感器网络地址配置方案

为实现无线传感器网络(WSN)与IPv6互联网的全IP通信,提出一种全IP WSN地址配置方案。将WSN分为多个簇,设计分布式IPv6地址配置方案,簇首节点采用有状态地址分配方式并引入接入节点动态树获取IPv6地址,簇成员节点通过无状态地址分配方式从一跳范围内的簇首节点处获取IPv6地址,且仅在本簇范围内进行重复地址检测。仿真结果表明,与6LoWPAN WSN分层地址配置方案相比,该方案的地址配置代价及延迟更小。     

基于分层架构的无线传感器网络节点编号分配算法

近年来,随着计算技术、网络技术和感知技术的发展,无线传感器网络也迎来了飞速发展。无线传感器网络不同于传统网络,多为专用网络,面向具体应用;并且网络中节点上的资源有限,所以传统网络的IP地址分配的方式不适合作为无线传感器网络中节点的全局唯一编号。针对无线传感器网络节点编号的分配问题,本文提出了一种分层式的无线传感器网络节点编号分配方案。在提出的方案中,网络中存在一个全局的编号分配中心服务器,同时存在若干个局部编号分配点,全局中心服务器和局部分配点共同完成无线传感器网络中节点编号的分配任务。这种分层式节点编号的分配方式减少了网络维护的代价,增强了网络的可扩展性,提高了无线传感器网络的可用性。     

基于定位信息的无线传感器网络IPv6地址配置方案*

提出了一种利用传感器节点定位信息实现无线传感器网络IPv6地址配置的方案.此方案根据定位信息将无线传感器网络划分为多个簇,簇首节点采用无状态策略为簇内节点分配IPv6地址.分析了此方案与Strong DAD及MANETConf的重复地址检测开销、地址配置总开销及地址配置总延迟时间等性能参数,分析结果验证了此方案的性能优于Strong DAD及MANETConf.     

密集型传感器网络MAC地址复用压缩算法

针对传感器网络中MAC地址在通信时能量开销太大的问题,提出了一种新的适用于节点密集分布的MAC地址复用压缩算法.该算法将传感器网络节点进行区域网格分割,节点以区域为单位进行地址复用.为削弱因网络节点分布的非均匀性带给算法性能的负面影响,提出了通过标志位标识的非对称性MAC地址分配原则.理论和实验结果表明,该算法在密集型...     

无线传感器网络中的地址分配协议

地址用来标识节点,使能网络通信协议,在无线传感器网络中扮演重要角色.由于无线传感器网络中节点众多,再考虑其网络动态性,手动地为每个节点分配地址是一件繁琐甚至无法完成的工作,于是,地址分配协议成为必需.由于无线传感器网络自身所具有的特点,传统的DHCP协议和ad hoc网络的地址分配协议对其不再适用.分析了无线传感器网络地址分配协议的必要性,总结了地址分配协议需要解决的问题和所面临的挑战,并对已有地址分配协议进行了分类.介绍和比较了当前有代表性的地址分配协议,并指出了它们的问题,分析了地址分配协议下一步研究的重点.     

适用于ZigBee网络的借地址分配算法

无线传感器网络使用ZigBee技术默认的分布式地址分配机制(DAAM)为节点分配地址时没有考虑到网络拓扑结构的优化,造成了网络深度的浪费。为此,提出一种ZigBee网络分布式借地址分配(DBAA)算法,通过为节点分配两跳通信范围内的空闲地址优化网络拓扑,从而提高节点获得地址的成功率。理论分析和仿真结果表明：DBAA算法在地址分配成功率、平均通信开销和平均耗时方面性能优于DAAM和SLAR方案。     

结构化P2P网络中拓扑匹配问题研究

本文以Tapestry系统为例讨论了结构化P2P网络中覆盖层与物理网络不匹配问题,提出基于区域划分和IP地址的标识符分配方案,以及选取符合后缀匹配要求的最近节点作为邻居节点的策略来改善覆盖层与物理网络的匹配性,提高了路由效率。     

静态博弈模型下的无线传感器网络MAC地址分配算法

针对传感器网络地址分配过程中为了避免地址冲突而导致通信能耗较大的问题,提出了一种基于静态博弈模型的MAC地址分配算法MAAS.该算法将传感器节点看作博弈模型中的决策者,通过使模型达到纳什平衡来解决节点的MAC地址分配问题.在进行地址分配时,MAAS利用博弈模型中每个决策者可根据其邻居节点信息独立进行决策的性质,避免了节点在地址分配过程中发送大量的交互信息.实验结果表明,MAAS在保证较低冲突率的同时降低了地址分配过程中的通信消耗.     

事件驱动型传感器网络地址分配算法研究

无线传感器网络中的地址分配是应用的前提,但目前研究相对较少。分析现有的无线传感器网络地址分配协议,提出了一种基于最小跳数的按需分配的地址分配算法,在网络初始阶段构建最小跳数,当节点监测到事件根据最小跳数建立与Sink节点的通信,获取事件节点的通信地址。理论分析及仿真结果表明,该算法降低了协议自身的通信开销,满足了无线传感器网络中通信节点资源极其稀少和低功耗的需要。     

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