静叶片钢冷轧变形的研究

本文对１Ｃｒ１１ＭｏＶ静叶片钢进行了冷轧变形的研究。确定了宽展面积与压缩面积的关系，各道次的宽展面积与压缩面积比值，宽展与压下量的关系，以及压下量沿轧件宽向的分布。为选择坯料外形和尺寸，孔型设计以及制定压下制度提供依据。     

应用GMM的快速火焰检测

基于视频图像的火焰检测是火灾预防研究的重要内容。为提高检测效率,首先使用具有自适应背景变化的 高斯混合模型(GMM)来检测场景中的运动物体。然后针对运动物体,提取颜色特征和面积变化特征。最后,根据得 到的特征来识别场景中是否有火焰发生。该方法不仅可有效检测到视频中的火焰帧,还避免了非火焰场景中对计算时 间的浪费。     

Mean waiting time evaluation of packet switches for centrally controlled PBX''s

The performance analysis of packet switched networks usually does not account for the loss of transmission bandwidth caused by the switch processing time. In wide area networks, where transmission channels are of the order of 64 kbps or less, this is a valid approach since switch processing time is negligible compared to average transmission times for packets. However, in Local Area Networks (LANs), the transmission channels are usually of the order of 1 mbps or greater and thus when evaluating the performance of a LAN that is based on a packet switch, it is necessary to consider the effect of the switch processing time which is now comparable to that of the average packet's transmission time. This paper investigates the effect of this processing time on network performance, and an exhaustive cyclic queueing algorithm to minimise this effect on overall network performance is discussed. An approximate analytical technique for evaluating the performance of such a LAN is derived. This technique makes it possible to do interactive calculations which can be used in the provisioning and configuring of such networks.     

车载CAN网络中直接NM逻辑环的实现

为实时监控车载网络中的节点,在使用控制器区域网络(CAN)总线的车载网络中,设计并实现一种基于OSEK/VDX规范直接网络管理(NM)的车载NM系统。由车载网关通过CAN总线收集各网络节点的故障信息,通过IPv6无线网络上传至远程故障诊断服务器,并将得到的故障处理信息下发至有关节点,实现车载CAN网络与远程故障诊断服务器的信息交互。测试结果表明,各网络节点上线后能快速建立稳定的逻辑环通信,并为远程故障诊断提供操作平台。     

Coverage and connectivity issues in wireless sensor networks: A survey

Sensing coverage and network connectivity are two of the most fundamental problems in wireless sensor networks. Finding an optimal node deployment strategy that would minimize cost, reduce computation and communication overhead, be resilient to node failures, and provide a high degree of coverage with network connectivity is extremely challenging. Coverage and connectivity together can be treated as a measure of quality of service in a sensor network; it tells us how well each point in the region is covered and how accurate is the information gathered by the nodes. Therefore, maximizing coverage as well as maintaining network connectivity using the resource constrained nodes is a non-trivial problem. In this survey article, we present and compare several state-of-the-art algorithms and techniques that aim to address this coverage–connectivity issue.     

车载CAN总线脱离攻击及其入侵检测算法

CAN总线脱离攻击作为一种新型的攻击方式,通过CAN总线通信的错误处理机制,可以使节点不断产生通信错误并从CAN总线上脱离。针对上述攻击所引发的车载CAN总线通信安全问题,提出了一种车载CAN总线脱离攻击入侵检测算法。首先,总结了车载CAN总线脱离攻击发生的条件与特点,指出正常报文与恶意报文的同步发送是实现总线脱离攻击的难点,并利用前置报文满足同步发送的条件来实现总线脱离攻击。其次,提取了CAN总线脱离攻击的特征,通过累计错误帧的发送数量,并根据报文发送频率的变化实现了对CAN总线脱离攻击的检测。最后,利用基于STM32F407ZGT6的CAN通信节点模拟车内电子控制单元（ECU）,实现了恶意报文和被攻击报文的同步发送。进行了CAN总线脱离攻击实验和入侵检测算法的验证。实验结果表明,检测算法对高优先级恶意报文的检测率在95%以上,因此可以有效保护车载CAN总线通信网络的安全。     

军用无线局域网安全体系结构设计研究

无线局域网因其使用方便、扩展性好、传输速率高、抗干扰性能强等,已在军事通信领域得到广泛应用.对无线局域网技术进行了概述,分析了军用无线局域网的面临的安全威胁和安全需求,基于无线网络的网络模型设计了军用无线局域网的安全体系结构.     

特种车辆驾驶员辅助观察系统设计方法

本文提出了一种基于盲区分析的多摄像头的驾驶员辅助观察系统的设想。通过简化的模型分析了车外盲区,分析了摄像头的安装方法。最后设计了一个试验系统,该系统减少了原本存在的大部分车外盲区,扩大了驾驶员的视野,取得了很好的效果。     

交换机VLAN实验教学设计*

交换机的虚拟局域网技术在计算机专业实验教学中属于重点和难点,尤其是VLAN划分后的交换机端口转发规则更是学生理解掌握的瓶颈。对跨交换机的VLAN实验传统方案进行改进设计,强化交换机端口在转发帧的过程中依据的规则,弥补关于交换机端口转发规则的实验教学空白,能使学生更深刻更全面地掌握交换机技术。实验方案改进设计在教学改革、教学方法和教学效果三方面都取得良好效果。     

移动计算中的无线网络解决方案

本文针对移动计算中的无缝连接问题，讨论了最受关注的无线网终技术，重点介绍了基于GRPS或WAP技术的广域解决方案和基于WLAN的局域解决方案，并给出了一个具体应用实例。