基于无线传感器网络的远程结构健康监测系统研究

设计了一种基于无线传感器网络的结构健康监测系统,提出了一种结合层次拓扑结构的无线传感器网络、有线Internet网络以及无线CDMA1X网络的组网方案,并对光纤光栅传感器的特点进行了分析,加强了系统的可靠性和安全性,提高了数据传输质量,扩展了系统的应用范围。     

石油化工行业危险源监控系统设计

石油化工行业危险源监控系统拟通过建立自组无线传感器网络可以将各种传感器,如温度、湿度、压力、振动、光照、气体传感器或者振动、声音、磁力、微波等传感设备,通过无线的方式构成任意的网络拓扑,形成区域无线覆盖。实时监测、感知和采集网络分布区域内的各种环境或监测对象信息,从而准确判断温度压力过载、有毒有害气体泄漏、入侵者非法闯入等危险信号。现已完成了传感器网络节点和后台管理系统的研发工作,开发出了一套完整的无线传感器网络危险源监控系统的组网演示系统和原型系统。     

基于ZigBee的传感器网络的节水灌溉控制系统的研究

本文构建了一种基于ZigBee无线传感器网络的节水灌溉控制系统,并给出了系统的网络体系结构,重点研究了无线传感器网络的自组网过程;该系统能够监测植物土壤水分的变化,通过无线传感器的反馈数据对植物采取有效的节水灌溉措施。     

基于ZigBee技术的灵芝无线传感器监测网络

提出了一种监测灵芝生长环境的无线传感器网络(wireless sensor network)系统.传感器网络的节点由传感器部分、无线收发模块、单片机组成.节点传感器部分安装了温度传感器、湿度传感器、pH传感器、土壤水分传感器、光敏电阻传感器,并对相应的传感器工作原理进行了简单介绍.传感器网络的无线收发模块采用CC242...     

Zigbee打造Ad hoc低功耗传感器网络

无线通信、嵌入式系统和传感器技术的发展和融合,推动了无线传感器网络的发展.无线传感器网络是由分布于一定的监控区域内,用于监测特定环境信息的无线传感器网络节点组成的,已在城市管理、环境监测、危险区域的远程控制等领域得到了广泛研究与应用.因此,探索研究组网方便迅速、通讯顺畅、体积小、低能耗的无线传感器网络,具有重要的意义.     

利用ZigBee技术构建无线传感器网络

通过对新型、开放的无线互联技术ZigBee技术的分析；结合传感器技术、ZigBee、IEEE1451．2技术、路由协议，构建了一种无线传感器网络．分析讨论了基于“燃气表数据无线传输系统”的无线传感器结构和无线传感器网络的实现．     

基于无线传感器网络的节水灌溉系统设计

根据农田作物缺水信息,提出一种基于无线传感器网络的农田智能灌溉控制方法;探讨了传感器网络节能路由协议;实现了系统硬件与软件设计。系统综合运用无线传感器智能信息处理技术、无线数据通信技术以及基于Internet显示平台的监测点管理查询技术,将功能相同或不同的传感器构成智能化传感器网络,从而全面提升了系统的自动化与监测水平。分析了目前实现精确农业亟待解决的关键技术问题,结果表明,系统通过嵌入式控制技术完成智能化灌溉,可很好地实现节水。     

无线传感器网络WSN硬件设计

传感器网络节点作为一种微型化的嵌入式系统,构成了无线传感器网络的基础层支撑平台。因为无线传感器网络大部分是采用电池供电,工作环境通常比较恶劣,而且数量大,更换电池非常困难,所以低功耗是无线传感器网络最重要的设计准则之一,从无线传感器网络节点的硬件设计到整个网络各层的协议设计都把节能作为设计的目标之一,尽可能延无线传感器网络的寿命。本文介绍了无线传感器网络的概念、特点以及无线传感器网络节点的组成,重点分析比较节点各组成单元各种常用芯片的特点,并且始终将低功耗作为比较的重要标准之一。     

无线传感器网络的结构分析与加密方案

在简要介绍无线传感器网络特点的基础上,给出了无线传感器网络的体系结构,随着无线传感器网络的广泛应用,网络安全成了很多传感器网络应用的关键,最后提出了一种基于密钥预分配无线传感器网络中的加密方案。     

一种混合方式的无线传感器网络测试调试系统

无线传感器网络是典型的网络化嵌入式系统,由于其既涉及嵌入式系统的行为又涉及网络的行为,以及其应用相关性,使其测试调试变得困难复杂,无法构建一个通用的测试调试平台. 为有效地测试调试无线传感器网络,在分析已有的研究工作基础上,采用半实物的仿真策略,提出了一种混合方式的无线传感器网络测试调试系统,解决了纯粹软件仿真平台掩盖太多实际器件实现的细节和实际环境测试中嵌入式系统行为和网络行为不可见、不可控性的缺陷,达到了一种折中的效果. 最后给出了该系统在FPGA(field programmable gate array)上的实现实例;通过实验验证了该系统能够有效地对无线传感器网络应用进行测试调试.     

基于生物免疫原理的新型无线传感器网络安全算法

基于无线传感网络安全分析, 提出一种新型无线传感器网络安全算法. 该算法结合生物免疫原理, 通过建立入侵特征库, 使安全系统具有记忆功能和学习功能, 并利用粗糙集解决了传感器网络中信息的不确定性和不完整性. 仿真结果表明, 在网络运行时, 该安全算法可行, 且入侵检测率明显提高.     

Distributed Algorithms for Event Reporting in Mobile-Sink WSNs for Internet of Things

Wireless Sensor Networks(WSNs) have many applications, such as climate monitoring systems, fire detection, smart homes, and smart cities. It is expected that WSNs will be integrated into the Internet of Things(IoT)and participate in various tasks. WSNs play an important role monitoring and reporting environment information and collecting surrounding context. In this paper we consider a WSN deployed for an application such as environment monitoring, and a mobile sink which acts as the gateway between the Internet and the WSN. Data gathering is a challenging problem in WSNs and in the IoT because the information has to be available quickly and effectively without delays and redundancies. In this paper we propose several distributed algorithms for composite event detection and reporting to a mobile sink. Once data is collected by the sink, it can be shared using the IoT infrastructure. We analyze the performance of our algorithms using WSNet simulator, which is specially designed for event-based WSNs. We measure various metrics such as average residual energy, percentage of composite events processed successfully at the sink, and the average number of hops to reach the sink.     

带执行器节点的无线传感器网络协议研究

对带执行器节点的无线传感器网络系统的结构和特点进行介绍和分析，比较了带执行器节点的网络系统与普通的网络系统之间的不同．根据充分利用执行器节点的供电和通信能力，减少传感器节点的能耗的设计思想，设计了一种可行网络通信协议和执行器决策算法．然后利用无线传感器网络能量模型和网络通信模型对该协议进行能耗和网络响应时间分析．最后对本协议进行仿真分析，比较执行器节点存在和不存在两种网络的网络性能，结果说明利用系统中执行器节点的特性设计网络通信协议，可以有效地提高网络系统的事件响应时间和单事件能耗性能．     

概率函数检测随机多址接入无线传感器网络MAC协议分析

 提出了概率函数检测随机多址接入无线传感器网络MAC(FPRM)协议.在发送分组的时间1+a中,采用p(x)函数检测的控制策略,增加握手的ACK信号,提高无线传感器网络的传输效率.通过平均周期法的理论分析和选取不同的p(x)函数值的仿真实验,获得的结果相吻合.分析结果表明,FPRM协议能有效地分配无线传感器网络的信道资源,提高系统的传输质量.     

Reliable and Energy Efficient Target Coverage for Wireless Sensor Networks

A critical aspect of applications with Wireless Sensor Networks (WSNs) is network lifetime.Power-constrained WSNs are usable as long as they can communicate sense data to a processing node.Poor communication links and hazardous environments make the WSNs unreliable.Existing schemes assume that the state of a sensor covering targets is binary:success (covers the targets) or failure (cannot cover the targets).However,in real WSNs,a sensor covers targets with a certain probability.To improve WSNs’ reliability,we should consider that a sensor covers targets with users’ satisfied probability.To solve this problem,this paper first introduces a failure probability into the target coverage problem to improve and control the system reliability.Furthermore,we model the solution as the α-Reliable Maximum Sensor Covers (α-RMSC) problem and design a heuristic greedy algorithm that efficiently computes the maximal number of α-Reliable sensor covers.To efficiently extend the WSNs lifetime with users’ pre-defined failure probability requirements,only the sensors from the current active sensor cover are responsible for monitoring all targets,while all other sensors are in a low-energy sleep mode.Simulation results validate the performance of this algorithm,in which users can precisely control the system reliability without sacrificing much energy consumption.     

基于数字水印技术的无线传感器网络安全机制研究

利用数字水印技术实现无线传感器网络的安全性。首先分析数字水印用于解决无线传感器网络安全问题的可行性，然后采用基于跳频扩频技术的数字水印、基于数字水印的认证技术来保障无线传感器网络的安全，最后给出数字水印设计实例。研究表明，数字水印技术是一种有效的、切实可行的无线传感器网络安全解决方案。     

面向物联网的无线传感器网络异构组网技术研究

组网技术是实现大规模WSNs网络的基础之一,网络模型和节点位置部署是研究WSNs组网的重要内容.针对大规模无线传感器网络的特性,在研究和分析WSNs网络结构和物联网需求的基础上,结合Star模型和Mesh模型的优点,提出了一种面向物联网的WSNs新型网络模型;同时,结合密度优先原则和邻节点信息思想对RDF算法进行改进,提出了适合大规模WSNs的网络节点部署的NDF算法,其节省了网络能量、延长了网络寿命.试验表明:通过新型组网模型和NDF算法组建面向物联网的大规模WSNs网络,能够实时、精确的监测和采集测量数据,在节省了网络能量的同时也提高了网络数据的准确度.     

Online Distributed Fault Detection of Sensor Measurements

In wireless sensor networks (WSNs), a faulty sensor may produce incorrect data and transmit them to the other sensors. This would consume the limited energy and bandwidth of WSNs. Furthermore, the base station may make inappropriate decisions when it receives the incorrect data sent by the faulty sensors. To solve these problems, this paper develops an online distributed algorithm to detect such faults by exploring the weighted majority vote scheme. Considering the spatial correlations in WSNs, a faulty sensor can diagnose itself through utilizing the spatial and time information provided by its neighbor sensors. Simulation results show that even when as many as 30% of the sensors are faulty, over 95% of faults can be correctly detected with our algorithm. These results indicate that the proposed algorithm has excellent performance in detecting fault of sensor measurements in WSNs.     

带非均匀节点分布无线传感器网络的高效节能数据存储

现有大部分无线传感器网络的分布式数据存储方法都依赖于传感器节点定位系统,这会导致节点消耗大量的能量,而且这些方法主要是针对均匀分布的无线传感器网络的,并不适用于非均匀节点分布的传感网络。为了解决这个问题,提出一种非均匀节点分布传感网络的大数据路由存储算法,其目的在于减少传感器节点的实际分布和地址。为了进一步节省数据存储空间和能量消耗,将布隆过滤器(Bloom filter)集成到节点上,从而进一步减少数据丢失和网络能量消耗。文中算法提供了高效的搜索服务,使数据在网络内的存储分布和路由能量消耗更加均匀,进而提高了网络的生存时间。文中算法在容错情况下通过减少冗余数据来提供高效节能的存储,并进一步减少数据的路由开销和存储空间的浪费。     

Molecular identification of a danger signal that alerts the immune system to dying cells

In infections, microbial components provide signals that alert the immune system to danger and promote the generation of immunity. In the absence of such signals, there is often no immune response or tolerance may develop. This has led to the concept that the immune system responds only to antigens perceived to be associated with a dangerous situation such as infection. Danger signals are thought to act by stimulating dendritic cells to mature so that they can present foreign antigens and stimulate T lymphocytes. Dying mammalian cells have also been found to release danger signals of unknown identity. Here we show that uric acid is a principal endogenous danger signal released from injured cells. Uric acid stimulates dendritic cell maturation and, when co-injected with antigen in vivo, significantly enhances the generation of responses from CD8+ T cells. Eliminating uric acid in vivo inhibits the immune response to antigens associated with injured cells, but not to antigens presented by activated dendritic cells. Our findings provide a molecular link between cell injury and immunity and have important implications for vaccines, autoimmunity and inflammation.