一种基于改进块匹配算法的运动车辆检测

针对传统块匹配算法计算量大、光照变化较敏感和实时性差的缺陷,本文对块匹配算法进行了相关研究,提出了改进算法。首先把两幅彩色图像转化为灰度图像,并通过概率松弛标记算法获得边缘图像,计算相邻两幅图像的差分图像得到运动区域,然后将差分图像与边缘检测图像相与得到运动区域的边缘信息,再进行匹配得到位移矢量场并对其进行矢量中值滤波,最后通过顺序区域增长将运动车辆分割出来。实验结果表明:本文方法相对于传统方法平均检测时间降低约58ms,而平均检测率提高了约6.7%。这种算法鲁棒性强、实时性好。     

无线传感器网络体系结构和关键技术研究

文章介绍了无线传感器网络的体系结构,提出了一种基于跨层设计的管理控制机制;在对无线传感器网络的关键技术,如媒体接入控制(MAC)技术和无线路由协议,分别进行阐述和比较的基础上,提出了一种把简单的IEEE 802 MAC协议应用于无线传感器网络的思想;为了提高系统容量,提出了多信道策略,可以用来有效减少系统碰撞阻塞率,减少接入时延;认为虽然无线传感器网络的应用前景非常广阔,但是仍存在很多问题,除了要尽量减少功耗外,必须提高系统容量,减少碰撞阻塞率,以加快无线传感器网络实用化的进程.     

Adaptive quality of service‐based routing approaches: development of neuro‐dynamic state‐dependent reinforcement learning algorithms

In this paper, we propose two adaptive routing algorithms based on reinforcement learning. In the first algorithm, we have used a neural network to approximate the reinforcement signal, allowing the learner to take into account various parameters such as local queue size, for distance estimation. Moreover, each router uses an online learning module to optimize the path in terms of average packet delivery time, by taking into account the waiting queue states of neighbouring routers. In the second algorithm, the exploration of paths is limited to N‐best non‐loop paths in terms of hops number (number of routers in a path), leading to a substantial reduction of convergence time. The performances of the proposed algorithms are evaluated experimentally with OPNET simulator for different levels of traffic's load and compared with standard shortest‐path and Q‐routing algorithms. Our approach proves superior to classical algorithms and is able to route efficiently even when the network load varies in an irregular manner. We also tested our approach on a large network topology to proof its scalability and adaptability. Copyright © 2006 John Wiley & Sons, Ltd.     

A survey of cross‐layer protocols for IEEE 802.11 wireless multi‐hop mesh networks

There has been an escalation in deployment and research of wireless mesh networks by both the business community and academia in the last few years. Their attractive characteristics include low deployment cost, a low‐cost option to extend network coverage and ease of maintenance due to their self‐healing properties. Multiple routes exist between the sender and receiver nodes because of the mesh layout that ensures network connectivity even when node or link failures occur. Recent advances among others include routing metrics, optimum routing, security, scheduling, cross‐layer designs and physical layer techniques. However, there are still challenges in wireless mesh networks as discussed in this paper that need to be addressed. Cross‐layer design allows information from adjacent and non‐adjacent layers to be used at a particular layer for performance improvement. This paper presents a survey of cross‐layer protocol design approaches applied to the IEEE 802.11 standards for wireless multi‐hop mesh networks that have been proposed over the last few years for improved performance. We summarize the current research efforts in cross‐layer protocol design using the IEEE 802.11 standard in identifying unsolved issues that are a promising avenue to further research. Copyright © 2016 John Wiley & Sons, Ltd.     

一种基于路径的新型自适应路由算法

构造了一种新型的路由表,设计了基于遗传算法的自适应路由算法(GAR),并在PC机上实现了简化的GAR.在局域网环境下,对GAR和基于跳计数准则的RIP的模拟试验表明,在相同的网络负载下GAR的平均通信延时是RIP的20%.该算法能够降低网络延时,平衡网络负载,提高网络性能.     

车内线缆的高空核电磁脉冲响应分析

复杂电磁环境中的车载电子设备受制于高空核电磁脉冲的威胁,其内置线缆的电磁效应与防护决定了特种车辆的生存能力及性能发挥。文中采用基于FTDT算法的电磁仿真软件CST,建立了车辆壳体的电磁模型以及车辆内置线缆布局模型,并仿真分析了车内线缆的高空核电磁脉冲电流电压响应。仿真结果表明,双绞线上响应电压较大而响应电流较小;同轴线的响应电压较小响应电流较大。有屏蔽体的线缆在HEMP照射时的响应电压电流和无屏蔽体时相比显著减小。但是,实际车辆壳体存在孔缝,响应电压电流的在部分频点产生谐振,导致电压电流出现较大值。文中的仿真分析结果对车载电子设备的电磁脉冲防护具有一定的实际工程意义。     

LLN中基于能量均衡的高效低时延路由算法

针对有损低功耗网络(Low-power and Lossy Network,LLN)中由于无线链路的有损特性以及节点部署不均匀无法有效实现网络能量均衡,提出一种基于能量均衡的高效低时延路由算法(Efficient Low Latency Routing Algorithm Based on Energy Balance in Low-Power and Lossy Networks,ELLEB-RPL)。该算法采用“ELLEB组网”策略,使得节点能够有效避免在DODAG(Destination Oriented Directed Acyclic Graph)间来回切换;通过采用“最优父节点选择”策略,使得节点选择的父节点达到最优;通过采用“流量自适应分配”策略,达到网络能量均衡的目的。仿真结果表明,ELLEB-RPL在Sink节点平均吞吐量、网络平均寿命以及端到端时延上均有提升。     

信令网MAP业务过程双路由问题分析报告

移动网络随着竞争的需要和移动互联网的发展,原有CS业务网络也逐步向IP化方向发展。目前,信令网络中存在由LSTP／HSTP点组成的E1信令链路网和NGN软交换组成的IP路由、本文对移动网中存在的双路由业务情况进行了深入的分析说明,对于信令网维护人员有一定参考价值,对提高信令监测系统数据的完整性有促进作用。     

大型医院内部网络系统集成的设计与应用

文中叙述了一个大型医院内部网络系统集成的设计方案,指出了网络总体结构设计、网络路由设计、网络安全设计是医院网络系统集成建设的重中之重,并给出了这三个部分的具体设计方案.最后给出了网络拓扑图及具体设备选型及实施方案.     

基于兴趣差异和中心性的AODV路由算法的改进

针对Ad Hoc网络中的消息传输问题,结合反应式路由算法AODV 和社会性路由算法Sim-Bet 基本思想,提出一种改进的路由算法---IC-AODV (基于兴趣因子和中心性的AODV 路由算法)。在选择转发节点时,综合跳数等物理因素和节点兴趣差异、中心性这两种社会性因素。随后用NS2对协议进行仿真,结果表明IC-AODV路由协议相比I-AODV (基于兴趣差异的AODV路由协议)等,在较低带宽开销的同时,获得更高可靠性与传输比。