基于OFDM的列车控制网络宽带系统

针对列车通信网络日益增长的带宽需求,提出一种TCN基带信号承载高频载波信号的信道共享解决方案,采用OFDM技术与TCN总线共用同一物理介质,在基带传输低速率、高可靠控制指令的同时,叠加更高频域的多媒体数据信息,实现信道复用.利用Matlab建立了列车控制网络宽带OFDM模型,并用FPGA实现了收发机样机系统,最后通过实验,验证了方案的可行性.     

基于BP算法的模糊Petri网在铁路客运站行车事故分析中的应用

针对铁路客运站行车事故致因过程的动态性以及事故原因的模糊性,提出了一种Petri网图形建模同模糊控制理论相结合的分析方法.根据具体的事故产生式规则,建立了行车事故的模糊Petri网模型,进一步又将神经网络的BP算法引入到模型参数的学习中,通过给出的模糊推理算法,推理计算出事故的主要原因及可信度.最后将该方法应用到某客运站行车事故分析中,结果证明了其在事故分析中的准确性和可行性.     

钝头列车加装底罩结构的减阻效果分析

为减少钝头列车的气动阻力,对车头圆顶、车体底罩、车间风挡的假想模型进行数值模拟计算。结果表明:钝头列车加装车体底罩及车头前部圆顶等结构,并以高于100km/h的速度运行时,减阻效果良好,行驶速度越高,减阻效果越明显。     

Parametric analysis of wheel wear in high-speed vehicles

In order to reduce the wheel profile wear of highspeed trains and extend the service life of wheels, a dynamic model for a high-speed vehicle was set up, in which the wheelset was regarded as flexible body, and the actual measured track irregularities and line conditions were considered. The wear depth of the wheel profile was calculated by the well-known Archard wear law. Through this model, the influence of the wheel profile, primary suspension stiffness, track gage, and rail cant on the wear of wheel profile were studied through multiple iterafive calculations. Numerical simulation results show that the type XP55 wheel profile has the smallest cumulative wear depth, and the type LM wheel profile has the largest wear depth. To reduce the wear of the wheel profile, the equivalent conicity of the wheel should not be too large or too small. On the other hand, a small primary vertical stiffness, a track gage around 1,435-1,438 mm, and a rail cant around 1：35-1：40 are beneficial for dynamic performance improvement and wheel wear alleviation.     

关于我国高速铁路列车运行图缓冲时间的研究

本文借鉴既有研究成果,从定量的角度研究了高速铁路列车运行图缓冲时间的优化取值问题。首先对缓冲时间的定义及分类等基本理论进行了总结,然后以某一列车初始晚点对后续列车造成的后效晚点时间总和为目标函数,研究这一总时间与缓冲时间取值的函数变化趋势,得出了缓冲时间在不同情况下的合理取值建议和方法。     

飞机降落冲击荷载作用下高铁隧道动力响应及疲劳损伤研究北大核心CSCD

针对运营期高铁隧道衬砌结构在飞机降落冲击荷载作用下的动力响应规律及疲劳损伤问题,以成自高铁下穿天府机场东二跑道区间隧道为工程背景,采用有限元分析的方法研究隧道动力响应及疲劳损伤规律。结果表明:B747-400型飞机在粗暴着陆后0.05 s时刻动力载荷达到最大值,约为500 kN;在单次粗暴着陆工况下,拱顶位移和受力最大,位移最大峰值为1.58 mm,拉应力最大峰值为437.79 kPa,压应力最大峰值为556.24 kPa,衬砌结构未出现塑性损伤;飞机荷载长期作用下,随着循环次数的增加,结构损伤部位和程度也随之增加,拱顶损伤最突出,其次为边墙,隧道衬砌在上方飞机长期粗暴着陆作用下的疲劳寿命大致为25 a。     

A Real-Time TCP Stream Reassembly Mechanism in High-Speed Network

With the continual growth of the variety and complexity of network crime means, the traditional packet feature matching cannot detect all kinds of intrusion behaviors completely. It is urgent to reassemble network stream to perform packet processing at a semantic level above the network layer. This paper presents an efficient TCP stream reassembly mechanism for real-time processing of high-speed network traffic. By analyzing the characteristics of network stream in high-speed network and TCP connection establishment process, several polices for designing the reassembly mechanism are built. Then, the reassembly implementation is elaborated in accordance with the policies. Finally, the reassembly mechanism is compared with the traditional reassembly mechanism by the network traffic captured in a typical gigabit gateway. Experiment results illustrate that the reassembly mechanism is efficient and can satisfy the real-time property requirement of traffic analysis system in high-speed network.     

JT/T325—2006《营运客车类型划分及等级评定》理解与实践

结合山西省的实际情况《山西省新增、更新、过户营运客车类型划分及等级核定表》,对交通部制定的《营运客车类型划分及等级评定》(JT/T325—2006)行业标准进行了详细的理解与实践,便于在工作中具有可操作性,更好地推进营运客车的类型划分及等级评定工作,确保道路客运事业健康发展。     

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由于机车牵引能耗的巨额经济成本和气体排放引起的污染问题,列车节能运行控制与研究日益重要。本文根据机车牵引力做功与能量转换方程分析了列车运行能耗的主要作用形态,即克服列车运行阻力和调速制动导致的动能损失。基于对运行阻力功和制动动能损失的考虑,从理论分析及仿真计算的角度,探讨了调速制动前的惰行距离和途中运行速度均衡性对列车运行能耗的影响。案例分析表明：在运行时分相近的要求下,通过避免不必要的制动调速和增加停站制动前的惰行距离,可降低运行能耗9%;通过设置合理的目标速度上下限保持列车运行速度均衡性,可降低运行能耗6.8%。     

哈夫曼算法在列车定位中的应用研究

精确地确定列车在线路中的位置是确保列车行车安全,更好的发挥运营效率.介绍哈夫曼算法,研究基于哈夫曼算法的列车定位技术.