无线传感器网络覆盖控制算法分析

网络覆盖算法直接影响无线传感器网络"感知"服务质量。文章根据传感器网络覆盖控制理论,对WSN的覆盖问题进行了归纳与总结,建立了WSN研究框架,从生存时间、部署策略、通信协议和组网等问题对无线传感器网络的覆盖控制策略和算法进行详细分析。     

无线传感器网络中覆盖控制技术综述

覆盖控制是无线传感器网络应用的一个基本问题,反映了网络所能提供的"感知"服务质量,可以使无线传感器网络的空间资源得到优化分配,进而更好地完成环境感知、信息获取和有效传输的任务;立足于无线传感器网络的覆盖控制问题,分析了网络覆盖技术在国内外研究的现状与发展,指出了传感器网络覆盖算法中需要解决的问题,并提出了将多目标进化算法与智能计算技术用于动态覆盖控制技术研究设想。     

WSN中基于网格的覆盖控制与群优化研究

覆盖问题是无线传感器网络部署研究的核心内容.指出了无线传感器网络覆盖控制问题的研究重心,并重点探讨了基于网格模型的无线传感器网络覆盖控制与群首优化问题.通过对覆盖概率分析,给出特定环境下监测区域的覆盖概率、群首个数和覆盖损失率之间的定量关系;分析不同参数对网络覆盖问题的影响,用以指导传感器网络的节点部署.最后,利用模拟仿真试验来评定结论.     

遗传算法在无线传感器网络覆盖中仿真研究

在无线传感器覆盖问题的研究中,传统覆盖算法存在节点覆盖区域间重复率高、能耗浪费从而导致网络覆盖效率低、网络寿命短的难题.为了提高无线传感器网络的覆盖率、延长网络生存时间,提出一种遗传算法优化的无线传感网络覆盖方法.首先把拓扑控制思想引入到网络节能覆盖中,无线传感器最大覆盖率为目标,建立一个感知半径之和最小的数学模型,然后利用遗传算法对模型进行求解,从而得到最优网络覆盖.最后进行仿真实验,仿真结果表明,相对于传统算法,不仅节能而且可以用较少的传感器节点获得较高覆盖率、有效地降低信道通讯干扰、提高网络的抗毁性.     

一种能量异构自适应的无线传感网络覆盖控制协议

网络感知覆盖和能量消耗是无线传感器网络的两个核心问题,两者密切相关.网络覆盖决定了无线传感器网络对物理世界的监测能力,反映了网络所能提供的"感知"服务质量,能量消耗则决定了无线传感器网络的生存时间.提出了一种节点能量异构自适应的无线传感网络覆盖控制协议HEAP(a Heterogeneous Energy Adaptive controlcoverage Protocol),HEAP采用基于节点分层成簇的思想,根据节点邻居平均能量与自身剩余能量等参数竞选活动节点.理论分析与模拟实验表明,HEAP协议不但能够提供高质量的网络覆盖率,而且可以有效地适应于节点能量异构的网络应用场景,并且减少活动节点选取过程中的控制消息开销.     

面向三维的无线传感器网络覆盖增强算法

覆盖作为无线传感器网络中基本问题直接影响着网络的服务质量,在分析传统二维无线传感器网络覆盖增强算法的基础上,建立新的传感器节点三维感知模型,在此基础上提出了一种面向三维空间的无线传感器网络覆盖增强节能算法.该算法通过智能算法优化调节传感器节点位置从而使节点比较均匀分布在监测区域中,在此基础上,采用集合覆盖模型算法计算出...     

基于微粒群优化的有向传感器网络覆盖增强算法

覆盖作为无线传感器网络监测中的基础问题反映了无线传感器网络的感知服务质量.在分析节点主感知方向可调模型的基础上,提出了一种微粒群优化的有向传感器网络覆盖增强算法.该算法针对节点主感知方向设计微粒适应值函数和种群进化策略, 以区域覆盖率为优化目标,通过微粒群优化有效调整传感器节点的主感知方向,从而达到有向传感器网络的覆盖增强.实验验证了算法的有效性.     

基于粒子群算法的无线传感网络覆盖优化策略

无线传感器网络覆盖控制是研究在保证服务质量条件下,为了实现网络覆盖范围的最大化.采用覆盖优化策略及算法的应用,有助于网络节点能量的有效控制、感知服务质最的提高和网络生存时间的延长.提出基于概率测量模型的粒子群优化策略,以网络有效覆盖率为优化目标,通过粒子群算法实现覆盖控制并详细分析了传感半径对覆盖性能的影响.仿真实验表明,粒子群优化策略的有效覆盖率达到了85.63%,能有效地实现无线传感网络覆盖优化.     

无线传感器网络一维区域的覆盖研究*

无线传感器网络覆盖问题的研究应综合考虑感知覆盖、通信覆盖和连通覆盖三个方面,建立适合不同监测空间的节点覆盖模型。讨论了无线传感器网络一维区域的覆盖问题,对无线传感器网络中一维直线区域出现的问题进行分析,讨论了均匀分布情况下的节点覆盖概率和覆盖数的计算方法,仿真实验表明节点感知半径是影响节点覆盖率和覆盖数的主要因素。     

无线传感器网络覆盖控制技术研究

无线传感器网络具有广泛的应用背景，目前已经发展成为一个重要的计算平台。但是，由于无线传感器网络自身的特点，使其也面临许多问题，如何有效地进行覆盖控制，在保证网络覆盖质量的前提下，减少能量消耗，延长网络寿命是其中最重要的问题之一。覆盖控制可以使无线传感器网络的资源得到优化分配，更好地完成环境监测、信息获取和数据传输等任务。本文总结了近年来提出的各种覆盖控制问题的、具有代表性的研究成果，并对相关覆盖控制协议与算法进行了分析比较，最后指出了目前覆盖控制技术存在的问题，对全文进行总结。     

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