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1.
在无线传感器网络路由协议中采用多跳通信的方式能够减少通讯距离、增强网络通讯的稳定性并提高网络能量利用效率,但是,由于靠近汇聚节点的簇头需要转发大量数据,容易导致能量快速衰竭而失效,造成“能量空洞”现象。提出了一种新型的基于能量均衡的多跳非均匀分簇路由算法(MUCRA),采用逐层成簇的策略,簇头以一定的半径广播分层信号,划分下一层网络区域非均匀层次,普通的传感器节点和簇头根据分层信息选择合适的网络路径。仿真实验结果表明:与经典的LEACH协议及EEUC协议相比,该算法能有效平衡网络负载,缓解“能量空洞”问题  相似文献   

2.
路智静  黄如  孙俊峰  张磊 《医学教育探索》2017,43(2):234-240,291
由于无线传感器能量受限,最大化网络生命周期成为优化网络拓扑首要考虑的问题。基于BA无标度理论,提出了一种WSNs拓扑优化模型(WTOM)。在网络中引入超级节点,结合粒子群算法合理地划分整个网络;在节点间建立多因素为导向的虚拟力场,利用虚拟力调整超级节点的部署位置,实现网络能量的均衡消耗,通过对关键节点的保护,提高网络的抗毁鲁棒性。经理论分析和实验证明,该网络不仅继承了BA无标度网络的特征还具有小世界特性;同时该动态拓扑延长了网络的生命周期,提高了网络面向数据收集的节能性。  相似文献   

3.
在传感网中如果2棵以Sink节点为根节点的生成树使得网络中任意源节点在这2棵树上到Sink节点的路径没有相交节点,称这2棵树为该网络的ND(Node Disjoint)树。针对工业无线传感网的应用需求与特点,研究了基于ND树的路由方案。仿真实验和分析表明,该路由方案具有较高的路由可靠性。针对该路由方案的特点与需要,给出了1种节点二连通(Twonodeconnected)网络的部署方案。  相似文献   

4.
在网络节点数量不断增加的情况下,JXTA基于洪泛的路由策略会使得网络中出现很多冗余的数据包,致使网络拥塞、路由效率低下,难以适应复杂的网络环境。结合蚁群算法和随机游走算法提出了一种动态路由算法,该算法对路由解析请求信息的转发规则做出改变,减少路由解析请求信息的转发数量,从而对JXTA的路由策略进行改进。利用Peersim网络模拟器进行了网络仿真实验,实验结果表明改进的路由算法可以明显减少冗余数据包的数量,有效提高了JXTA网络的路由效率。  相似文献   

5.
论述了在计算机互联网络系统中信息包的传递和路由选择过程、各种常用路由选择技术的特性,以及不同路由选择协议的合理使用,并介绍了应用实例,说明了在大规模互联网络方案的设计中,选择合理的路由选择协议,对发挥网络的最佳性能、方便网络的维护和升级具有重要的作用.  相似文献   

6.
无线传感器网络(Wireless Sensor Networks, WSNs)是一种新兴的传感器网络。Leach(Low energy adaptive clustering hierarchy)协议是WSNs中最流行的簇类协议之一,它通过概率模型选择簇头,并且周期性地改变簇头来实现最大化的网络覆盖率和网络寿命。本文通过网络中节点的能量和所处的地理位置信息,对Leach协议中节点成为簇头的概率公式进行修正,从而改进协议的簇头选择算法,平衡网络的能耗,达到延长无线传感器网络寿命的目的。基于NS2(Network Simulator Version 2)平台的实验结果证明,改进的Leach算法可以延长WSNs的寿命。  相似文献   

7.
在传感器网络中,传感器节点本身的通信能量与功率有限,传感器节点仅与其邻域中的相邻节点进行合作与通信,这说明网络中演化过程符合局域演化概念。从无线传感器网络局域演化角度出发,综合考虑传感器网络中节点能量感知连接机制以及节点和链路有增有减的动态过程,提出了一种能量感知的局域世界动态演化模型。利用平均场理论分析并仿真验证了该模型的度分布介于随机网络和无标度网络之间。同时,通过仿真实验研究了所提模型的网络直径和网络能效与局域世界规模的关系,实验结果表明适当增加节点的局域世界可以大大提高网络数据传输的高效性。  相似文献   

8.
为降低无线传感器网络中的能量开销,减少存储和网络资源,采用了一种新的信息融合机制。根据目标的当前地理位置,将无线传感器网络中的节点动态分簇,建立分布式的跟踪机制。利用一种基于信息矩阵加权的卡尔曼算法在该机制下进行目标跟踪,与无分簇机制下的信息矩阵融合算法进行性能比较,仿真实验结果表明该方法具有较高的有效性和可靠性。同时,在网络存在丢包情况下,基于Grubbs准则进行改进,能有效地提高精度。  相似文献   

9.
基于P2P技术的手术视频网络教学系统设计   总被引:1,自引:1,他引:1  
为克服传统Client/Server模式视频网络系统的不足,指出并设计了一种基于P2P技术的手术视频教学系统。在介绍其技术原理、单源传输树模型的基础上,讨论了路由查找、语意搜索、负载均衡、文件分片和传输等模块的实现方法。指出通过网络教学实践,该系统具有网络资源利用率高、扩展性好、成本低等优点,可推广到其他教学领域。  相似文献   

10.
随着无线传感器网络的应用与发展,WSN作为一种全新的信息获取和处理技术已得到广泛应用。如何对传感器网络节点进行快速、精确的定位,已成为WSN系统急需解决的问题。为此,提出了一种基于RSSI距离比的MDS定位算法。该算法巧用RSSI距离比,结合Euclidean测距技术计算节点间距离矩阵,运用MDS算法建立相应的全局坐标系统。根据已知锚节点物理位置,通过坐标变换(旋转与平移)最终确定未知节点的物理位置。实验结果表明:该方法能有效地提高定位的精度,对开发高精度定位系统具有重要的参考价值。  相似文献   

11.
12.
In order for wireless body area networks to meet widespread adoption, a number of security implications must be explored to promote and maintain fundamental medical ethical principles and social expectations. As a result, integration of security functionality to sensor nodes is required. Integrating security functionality to a wireless sensor node increases the size of the stored software program in program memory, the required time that the sensor's microprocessor needs to process the data and the wireless network traffic which is exchanged among sensors. This security overhead has dominant impact on the energy dissipation which is strongly related to the lifetime of the sensor, a critical aspect in wireless sensor network (WSN) technology. Strict definition of the security functionality, complete hardware model (microprocessor and radio), WBAN topology and the structure of the medium access control (MAC) frame are required for an accurate estimation of the energy that security introduces into the WBAN. In this work, we define a lightweight security scheme for WBAN, we estimate the additional energy consumption that the security scheme introduces to WBAN based on commercial available off-the-shelf hardware components (microprocessor and radio), the network topology and the MAC frame. Furthermore, we propose a new microcontroller design in order to reduce the energy consumption of the system. Experimental results and comparisons with other works are given.  相似文献   

13.
A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.  相似文献   

14.
针对非均匀监测点的节点部署问题,设计并实现了一种简单、实用的果蝇优化算法(WSN-IFOA),构造了适用于节点部署的味道浓度函数。利用果蝇群体的随机寻优性,能够保证部署尽可能少的传感器节点使网络覆盖和连通。实验结果表明该算法在部署效果上优于基本蚁群算法,并证明了算法的可行性和有效性。  相似文献   

15.
通过路径发现和分析可以挖掘社会网络中人与人之间的关系及其连接特性,特别是在犯罪网络的应用中具有重要意义。通过社区发现算法获得社区间的重叠节点,并构造目标网络的分层网络模型;基于社会网络的高聚集系数特性及幂律分布拓扑特征,提出了基于重叠节点的分层网络路径发现(HOLN)算法,以核心节点距离代替社区间距,优化路径搜索方向;优先搜索重叠节点,简化对节点的遍历,实现源与目标间最短路径的快速发现。实验结果表明,本文提出的HOLN算法在计算精度和运行效率上都有令人满意的表现。  相似文献   

16.
In the wireless sensor network(WSN) security is a major issue. There are several network security schemes proposed in research. In the network, malicious nodes obstruct the performance of the network. The network can be vulnerable by Sybil attack. When a node illicitly assertions multiple identities or claims fake IDs, the WSN grieves from an attack named Sybil attack. This attack threatens wireless sensor network in data aggregation, synchronizing system, routing, fair resource allocation and misbehavior detection. Henceforth, the research is carried out to prevent the Sybil attack and increase the performance of the network. This paper presents the novel security mechanism and Fujisaki Okamoto algorithm and also application of the work. The Fujisaki-Okamoto (FO) algorithm is ID based cryptographic scheme and gives strong authentication against Sybil attack. By using Network simulator2 (NS2) the scheme is simulated. In this proposed scheme broadcasting key, time taken for different key sizes, energy consumption, Packet delivery ratio, Throughput were analyzed.  相似文献   

17.
Background Although clinical treatment for heart failure and sudden death has been improved over the last few decades, the morbidity and mortality of dilated cardiomyopathy (DCM) have increased. So a better understanding of the underlying molecular events leading to DCM is urgent. Persistent viral infection (especially coxsackievirus group B3) of the myocardium in viral myocarditis and DCM has never been neglected by experts. Recent data indicate that the up-regulation of coxsackievirus and adenovirus receptor (CAR) in viral cardiomyopathy contributes to viral infection as a key factor in the pathogenesis of this disease. This study aimed to investigate the role and regulatory mechanism of CAR in DCM by the bioinformatic method. Methods We identified the clusters of genes co-expressed with CAR by clustering algorithm based on the public available microarray dataset of DCM (Kittleson, et al. 2005), and mapped these genes into the protein-protein interaction networks to investigate the interaction relationship to each other at the protein level after confirming that the samples are characterized by the cluster of genes in correctly partitioning. Results The gene cluster GENESET 11 containing 33 genes including CAR with similar expression pattern was identified by cluster algorithm, of which 19 genes were found to have interaction information of the protein encoded by them in the current human protein interaction database. Especially, 12 genes present as critical nodes (called HUB node) at the protein level are involved in energy metabolism, signal transduction, viral infection, immuno-response, cell apoptosis, cell proliferation, tissue repair, etc. Conclusions The genes in GENESET 11 together with CAR may play a pathogenic role in the development of DCM, mainly involved in the mechanism of energy metabolism, signal transduction, viral infection, immuno-response, cell apoptosis and tissue repair.  相似文献   

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