破碎压实技术对城镇道路地下管道的振动影响与安全评价

破碎压实技术能将旧水泥混凝土路面破碎与压实后,直接作为新路面的基层或底基层使用,它在旧水泥混凝土路面改造中有越来越广泛的应用。然而,破碎机械对城镇道路地下管道会产生冲击振动,影响管道的安全。作者以MHB（多锤头破碎）机械为研究对象,分析冲击波的传递规律和面层结构的振动,并给出了振动引起的附加动应力和Steverding...     

城市公路隧道多匝道通风系统计算方法的探讨

文章以某一实际工程为例,介绍了SES模拟软件在多匝道公路隧道通风系统中的应用。在多匝道和多交叉的公路隧道工程中,可以采用SES模拟软件对隧道通风系统进行辅助计算,成功地解决多匝道通风系统的难题,为今后类似工程的计算和设计提供新的思路。     

动力分散型城郊快速电动车组转向架方案设计

介绍一种动力分散型城郊快速电动车组转向架的主要技术参数和基本结构方案。     

A parameterized consideration set model for airport choice: an application to the San Francisco Bay Area

Airport choice is an important air travel-related decision in multiple airport regions. This paper proposes the use of a probabilistic choice set multinomial logit (PCMNL) model for airport choice that generalizes the multinomial logit model used in all earlier airport choice studies. The paper discusses the properties of the PCMNL model, and applies it to examine airport choice of business travelers residing in the San Francisco Bay Area. Substantive policy implications of the results are discussed. Overall, the results indicate that it is important to analyze the choice (consideration) set formation of travelers. Failure to recognize consideration effects of air travelers can lead to biased model parameters, misleading evaluation of the effects of policy action, and a diminished data fit.     

中高速列车共线运行的仿真研究

以京沪高速为背景,对中高速列车共线运行仿真问题进行探讨。分别建立单列车运行模型和多列车共线运行模型。单列车运行模型全面考虑了列车物理特性、线路条件、列车受力情况以及运行控制过程。多列车模型在上述基础上,附加了共线运行不同速度列车间的相互影响,对列车间距控制和避让进行了重点考虑,研究多列车共线运行时的列车间距控制策略和避让策略。用VisualC 6 0进行了中高速列车共线运行的软件实现。仿真计算结果表明,该软件能较好模拟多列车共线运行情况,可作为列车调度系统中负责列车运行模拟的子系统。     

The relationship between land use and automobile travel utility: A Multiple Indicators Multiple Causes approach

The relationship between land use and the utility of automobile travel is examined by refining the utility concept, particularly by combining the microeconomic utility theory, which is concerned with the disutility of travel, and the perspective on the positive utility. A conceptual model is accordingly developed and then adjusted considering different purposes of travel. The purpose-specific models are tested through a Multiple Indicators Multiple Causes approach in Seoul, Korea, using datasets from a sample survey and geographic information systems. The major finding is that land use affects the utility mainly by changing synergy and affective utility rather than instrumental utility, which encompasses disutility variables. Among land use variables, the utility is found to be the most sensitive to the number of transit facilities for commuting and shopping travel and land use balance for leisure travel.     

基于多元智能理论的高职高专英语教学

八十年代,美国著名发展心理学家、哈佛大学教授霍华德.加德纳(Howard Gardner)提出了多元智能理论。该理论倡导学校和教师应关心每个学生的成长,为学生的发展提供不同的选择机会。本文从多元智能理论的角度,对高职高专学生学习英语困难的现状作一全新剖析,并提出应用多元智能理论来调动这些学生参与英语学习的教学策略。     

基于多线程技术的网络化数控加工系统

利用VC 多线程技术研制出基于网络的数控机床远程控制系统，可使计算机与数控机床进行远程数控代码接收与发送，为数控机床群的网络化控制与管理奠定了必要技术基础．本系统得到成功应用并取得良好的效果．     

Impact of channel estimation error on channel capacity of multiple input multiple output system

In order to investigate the impact of channel estimation error on channel capacity of multiple input multiple output （MIMO） system, a novel method is proposed to explore the channel capacity in correlated Rayleigh fading environment. A system model is constructed based on the channel estimation error at receiver side. Using the properties of Wishart distribution, the lower bound of the channel capacity is derived when the MIMO channel is of full rank. Then a method is proposed to select the optimum set of transmit antennas based on the lower bound of the mean channel capacity. The novel method can be easily implemented with low computational complexity. The simulation results show that the channel capacity of MIMO system is sensitive to channel estimation error, and is maximized when the signal-to- noise ratio increases to a certain point. Proper selection of transmit antennas can increase the channel capacity of MIMO system by about 1 bit/s in a flat fading environment with deficient rank of channel matrix.     

成都地铁票务管理信息化实践

针对成都地铁票务管理上的难点和痛点,通过信息化手段和互联网+的应用,对原有的现金收益审核工作进行无纸化改造,在车站购票/充值环节提供移动支付功能,解决票务运作上重复性工作量大、人工作业环节效率低易出错、业务人员数量随着线网规模不断增大等突出问题,基本实现票务管理的信息化、自动化和网络化,提质、增效、降成本效果显著。同时相关功能均是基于已运营的线路进行改造,可为其他城市改变既有的票务管理提供借鉴。