青藏铁路新型路基保温材料应用试验研究

为考察聚苯乙烯泡沫板(EPS)和聚氨酯泡沫板(PU)的工程应用效果,在青藏铁路多年冻土路基试验段进行了现场测试.结果表明,2种新型保温材料均具有较好的保温隔热性能,且PU板优于EPS板,保温性能与板厚之间存在非线性关系.较之对比断面,有保温板的断面基底年平均地温降低,上限抬升,有利于保护多年冻土.动态行车试验表明,保温板路基满足列车以100 km/h的速度运行的安全性与舒适性要求.     

Robust Principal Component Test in Gross Error Detection and Identification

Principle component analysis (PCA) based chi-square test is more sensitive to subtle gross errors and has greater power to correctly detect gross errors than classical chi-square test. However, classical principal component test (PCT) is non-robust and can be very sensitive to one or more outliers. In this paper, a Huber function liked robust weight factor was added in the collective chi-square test to eliminate the influence of gross errors on the PCT. Meanwhile, robust chi-square test was applied to modified simultaneous estimation of gross error (MSEGE) strategy to detect and identify multiple gross errors. Simulation results show that the proposed robust test can reduce the possibility of type II errors effectively. Adding robust chi-square test into MSEGE does not obviously improve the power of multiple gross error identification, the proposed approach considers the influence of outliers on hypothesis statistic test and is more reasonable.     

Calculation of 3D sensitivity matrix for electromagnetic tomography system using boundary elements and the perturbative approach

Electromagnetic tomography （EMT） is a non-invasive imaging technique capable of mapping the conductivity and permeability of an object. In EMT, eddy currents are induced in the object by the activation coils, and the receiving coils can measure the EMT voltages. When the activation frequency is significantly large, we can treat the metallic targets as electrically perfect conductors （EPCs）. In this situation, a thin skin approximation is reasonable and this type of scattering problem can be effectively treated by the boundary element method （BEM） formulated through integration equations. In this study, we compute three-dimensional （3D） sensitivity matrix between the sensors due to an EPC perturbation. Efficiency improvement is achieved through the utility of scalar magnetic potential. Two EPC objects, one sphere and one cube shaped, are simulated. The results agree well with the H dot H formula. Overall, we conclude that BEM can be used to calculate the 3D sensitivity matrix of an EMT system efficiently. This method is a general one for any shaped objects while the H dot H solution is only capable of producing the response for a small ball.     

Application of novel rotation angular model for 3D mouse system based on MEMS accelerometers

A new scheme is proposed to model 3D angular motion of a revolving regular object with miniature, low-cost micro electro mechanical systems (MEMS) accelerometers (instead of gyroscope), which is employed in 3D mouse system. To sense 3D angular motion, the static property of MEMS accelerometer, sensitive to gravity acceleration, is exploited. With the three outputs of configured accelerometers, the proposed model is implemented to get the rotary motion of the rigid object. In order to validate the effectiveness of the proposed model, an input device is developed with the configuration of the scheme. Experimental results show that a simulated 3D cube can accurately track the rotation of the input device. The result indicates the feasibility and effectiveness of the proposed model in the 3D mouse system.     

山区公路路线设计探讨

结合承德山区某公路设计,对山区公路路线设计中的线形选择、沿河溪线设计、线形标准选择、圆曲线设计、凹凸曲线设计、环境保护等进行分析与探讨,并对山区公路路线设计中容易忽视的问题提出建议。     

小型公路路面加速加载试验设备MMLS1/3

以路面加速加载试验设备为研究对象,对其主要种类和特点进行比较分析,重点对小型公路路面加速加载试验设备MMLS的技术参数、系统总成和测试内容进行了分析,结果表明小型设备MMLS具有体积小,移动方便,加载速度快,能够模拟路面不同干湿条件和温度条件,可以在较短的时间内建立路面结构使用性能指标的变化规律,从而得到对沥青路面结构长期使用性能的评价.     

高速公路匝道交通安全的综合评价

高速公路匝道安全问题直接影响整条高速公路乃至区域路网的交通运行效率。为了提高匝道安全性和服务水平,在分析高速公路匝道事故特点和原因的基础上,提出了适用于匝道交通安全的评价指标,并建立了相应的评价体系;采用层次分析法与熵值法相结合的方式确定评价指标的权重,应用模糊评价方法给定综合评价值,同时应用于宁杭高速公路匝道交通安全的综合评价,评价结果与实测数据相吻合。     

河谷型城市公交线网特征与规划

本文针对我国河谷型城市在现有公交线网规划中存在的诸多问题,从河谷型城市的定义与特征入手,分析了河谷型城市公交线网的特征和存在的问题,就河谷型城市公交起讫点和换乘枢纽的设置进行了研究,阐述了几种相应的布局模式各自的优缺点及适应条件。通过对河谷型城市所具备特点的综合分析,并结合现有的交通方式,提出了适合我国河谷型城市公共交通发展的规划模式,从多方面对河谷型城市公共交通规划提出了改进意见,对河谷型城市公交线网规划具有一定的指导作用。     

大型活动中突发事件对交通流的时空影响

为了研究大型活动消散过程中交通流分布状况,分析了大型活动中突发事件对交通流分布的时空影响特征,总结了突发事件下常用的交通管制和疏导措施,将静态多路径交通分配方法与元胞传输模型(CTM)相结合,设计出了适合突发事件下的准动态交通分配方法.对一个小规模路网进行仿真,计算了突发事件下各交叉口节点的拥堵时刻,研究了路网拥堵的形成及消散的时空变化规律,并对两组不同管控方案下交通流疏散效率进行了对比.对比结果表明:不同控制方案下的路网在仿真时段内平均车辆延误分别为197、232 S·pcu-1,由该指标可以判断方案一优于方案二,因此,基于CTM的准动态交通分配方法可定量评价突发事件下交通组织方案的效果.     

基于Web的城市公安综合信息管理系统设计

城市公安信息管理系统是对各种公安信息进行处理的计算机应用系统,它可以规范公安系统管理流程、提高办公效率、加强决策支持、具有非常现实的意义.在分析当前公安信息管理现状的基础上,设计了一个基于Web的城市公安综合信息管理系统.