A proposed vision and vehicle-to-infrastructure communication-based vehicle positioning approach

It is essential to obtain accurate location of vehicles for new applications of Intelligent Transportation Systems. To remedy the defects of present Global Positioning System and vehicle-to-infrastructure (V-I) positioning technology, a new positioning approach based on vision and V-I communication is proposed. This approach aims at lane-level positioning with lower cost than conventional ones. In this approach, the position of the vehicle is represented by its lateral position (the lane number) and longitudinal position (the distance from entrance of the road) in a course coordinate system along the road; the specific lane the vehicle is occupying (the lane number) can be judged using the information of lane lines detected by vision systems; then the distance to the vehicle is obtained by a Road Side Unit (RSU) during the V-I communication; and the longitudinal position is calculated. The error of the approach on typical operating conditions is analyzed, indicating that the new approach can achieve the accuracy of less than 0.31 m for straight road and 0.58 m for typical arc road with ultra-wideband communication and ranging technologies and rational arrangement of RSUs. The feasibility of this approach is presented.     

网络化车钟通信的设计与实现

文章阐述了网络化车钟通信硬件控制设计、网络化组成以及通讯协议的编制,着重介绍了所设计的控制电路以及软件通讯规约。其中的关键技术是车钟通信系统的CAN总线的网络化实现。     

基于 SIP 协议航管内部通信系统的设计

论文介绍了航管内部通信系统的特点,会话初始协议 SIP（Session Initialization Protocol）协议的功能特性,给出了基于 SIP 协议航管中心内部通信系统的设备组成,陈述了整个内部通信系统的系统架构和主机的软件架构,内部通信系统工程实现的关键技术,最后对航管内部通信进行了小结。     

跳频通信系统抗跟踪式干扰性能研究

对于跳频通信系统,跟踪式干扰是一种较有效的干扰样式。分析了干扰方程并进行了仿真,认为干扰机配置位置必须在干扰椭圆内跟踪式干扰才能有效实施干扰,提高跳速是对抗跟踪式干扰的一种有效方法。     

基于归一化误差函数的变步长分数间隔盲均衡算法研究

针对常数模算法收敛速度慢的特点,提出了一种快速收敛的盲均衡算法。该算法修改了传统常数模算法的误差函数,且采用可变步长和分数间隔采样,有效地提高了收敛速度。浅海水声信道模型仿真结果表明,采用归一化变步长分数间隔常数模盲均衡算法比传统的常数模算法和固定步长分数间隔算法收敛快,均衡性能有明显提高。     

集装箱码头800M数字集群通信系统制式的选择

介绍了数字集群通信系统的特点,对数字集群系统两种制式作了比较。分析了集装箱码头对通信系统的要求和目前国内iDEN系统的运行状态。     

Instantaneous communication throughputs of vehicular ad hoc networks

Vehicular ad hoc networks (VANETs) formed by connected vehicles in a traffic stream could be applied to improve safety, mobility, and environmental impacts of a transportation system. In this paper, we present analytical models for the instantaneous communication throughputs of VANETs to measure the efficiency of information propagation under various traffic conditions at a time instant. In particular, we define broadcast and unicast communication throughputs by the wireless channel bandwith multiplied by the average probabilities that one vehicle is a successful receiver and sender in a VAENT, respectively. With a protocol communication model, we derive formulas to determine the probabilities for an equipped vehicle to be a successful broadcast receiver and a successful unicast receiver/sender, and obtain broadcast and unicast throughputs along discrete and continuous traffic streams. We further examine the impacts on communication throughputs of the transmission range and the interference range of dedicated short range communication devices as well as the market penetration rate of equipped vehicles and the percentage of senders. Finally, we investigate the influence of shock waves on communication throughputs.     

线性绞车电控系统开发与应用

基于广州打捞局120 000 kN抬浮力打捞工程船配套4 500 kN线性绞车的技术要求,提出线性绞车电控系统设计方案。从线性绞车在打捞工程船中的作业工况、电控系统的通讯架构、线性绞车单台控制及远程联动的自动控制、人机界面操作等方面进行研究,介绍线性绞车电控系统的设计思路,为线性绞车在打捞沉船工作中的正确运用提供了理论支撑和技术保障。     

交通职业技术学院学生职业价值观问题研究

市场经济所带来的多元化择业观念,使毕业生集体主义观念和社会责任感观念淡化,从而在就业选择上趋向于功利化、自我化。文章针对当前交通职业技术学院学生职业价值观的这一变化,分析学生现实型职业价值观与传统型职业价值观之旬的冲突,提出了交通职业技术学校在职业价值观教育方面应采取的措施。     

交通技工学校学生厌学现象分析及对策研究

文章针对交通技工学校学生厌学现象,从社会、家庭、学校、学生自身等方面深入分析了学生厌学的原因,提出了解决厌学问题的对策与措施。