The effect of attitudes toward cars and public transportation on behavioral intention in commuting mode choice—A comparison across six Asian countries

This study investigated the contribution of psychological factors in explaining the choice of transportation mode in six Asian countries. Data were collected from 1118 respondents in Japan, Thailand, China, Vietnam, Indonesia, and the Philippines. The dependent variable was the intention to use one of three modes for work travel after getting a job: car, public transit, or other modes. The explanatory variables were three attitude factors taken from a previous study, including: 1/symbolic affective, reflecting affective motives of travel mode use; 2/instrumental, referring to functional attributes of travel modes; and 3/social orderliness which represents for environmental friendliness, safety, altruism, quietness et cetera. Several logit model estimates were made using the samples from the six countries separately and together. We obtained three main findings. First, attitude variables about the car were all significant determinants for the entire sample from Asian countries. Second, the social orderliness aspect of public transit was a common concern of respondents from developing countries in selecting this mode for work trips. Third, in countries in which the intent to use a car was not very high, attitude factors about the car were found to be significant determinants of the behavioral intention to commute by car but were less significant in countries in which the desire to use a car was high.     

Does the income elasticity of road traffic depend on the source of income?

An extensive body of literature addresses the income elasticity of road traffic, in which income is typically treated as a homogenous quantity. Here we report evidence of heterogeneity in cross-sectional estimates of the elasticity of vehicle-kilometres of travel (VKT) with respect to income, when household income is disaggregated on the basis of income source.The results are generally intuitive, and show that the cross-sectional income elasticity of road traffic is not homogeneous as is typically specified in transport planning models. We show that in a number of circumstances the cross-sectional elasticity with respect to aggregate household income is of the opposite sign in comparison to more refined estimates of elasticity disaggregated by income source. If further research confirms that the elasticities we report here are causal in nature, neglecting the elemental effects could result in misleading results affecting practical infrastructure-investment and policy decisions, particularly as the mix of income sources shifts (e.g. if, as society ages, pension income increases as a share of all income).These results are of interest to both researchers and forecasters of travel demand, as well as designers of future travel survey instruments; the latter group must decide how to generate data about respondents’ income. Current expert guidance is to collect a single estimate of aggregate income at the household level. Future travel survey design choices will bound the analyses that can be supported by the resulting survey data, and therefore methodological research to re-visit the trade-offs associated with such choices is warranted.     

砂质黄土大断面隧道施工方法优化研究

研究目的:采用数值计算的方法,对砂质黄土大断面开挖方法进行优化研究,并对选择的方法进行仿真分析,根据围岩力学行为及分布规律,得到更为适合现场的施工方法。研究结论:以工程实例为对象,以数值计算和工艺研究为手段,对大断面隧道开挖方法进行优化研究,研究结果表明:砂质黄土大断面隧道施工中,短台阶七步法在施工力学方面分布合理,更有利于围岩稳定,总体沉降较小,相比CD和CRD方法具有较好的适应性。短台阶七步法在砂质黄土地层中施工作业面连续,整体作业面大,适于大型机械施工,施工速度快,效益明显。     

A note on the use of correlation coefficients for assessing goodness-of-fit in spatial interaction models

The use of correlation coefficients to evaluate the accuracy of spatial interaction models is inappropriate unless such models have been fitted using least squares techniques. In other cases the correlation involves an implicit intercept value and a regression coefficient that may significantly modify the interaction model's estimates. Researchers have not acknowledged the role of these two parameters when the correlation is used. A generalized root mean square error is proposed as an alternative indicator of accuracy that may be used with any model.     

胜利采油厂注聚南区渗氮管线腐蚀原因分析

综合利用材质分析、腐蚀速率测试、腐蚀产物分析等手段对胜利采油厂胜二区注聚南区腐蚀穿孔渗氮管线样品进行了测试分析,结果表明该管线腐蚀很严重。经过进一步分析,确定了管线的腐蚀原因并得出结论如下：母液管线腐蚀原因为服役于强腐蚀性介质中,渗氮层局部缺陷处的点蚀穿孔;单井管线腐蚀原因为Cl^-促进作用下的溶解氧腐蚀;20号钢渗氮管不宜做为该服役环境下的注聚管。建议更新穿孔管线,内防采用重防腐涂层,外防采用三层PE;对未穿孔管线,采用非开挖内涂衬技术,以提高管线运行可靠性。     

高速公路软土地基沉降预测方法现状探讨

沉降预测是修建在软土地基上的高速公路迫切需要解决的问题.概述了现有的各种传统和新的沉降预测方法,并分析各预测方法的优缺点,指出影响各预测方法精度的主要因素有交通荷载及超载、软土路基沉降变形机理,以及沉降观测数据典型性与采集时间序列长度.通过比较分析表明,有限元方法在沉降计算时的独特优势越来越明显,用有限元方法来预测软土...     

结构局部分析子系统JF的开发

本文阐述了结构局部分析子系统 JF 的设计思想和主要手段,并以实例说明该系统完全适用于铁道车辆主型货车车体结构设计,实现结构分析数据的自动生成,达到预期的目的.     

导向法铺管技术在城市污水管铺设中的应用

在道路拓宽改造及其它客观条件不允许大开挖埋设污水管工程中，通过使用导向法铺管技术，利用其先进的导航系统，能够经济、快速、准确地完成铺设管道任务。该方法利用地面上导航仪，引导地面下装有无线电发射器的钻机钻头沿着根据施工图要求的污水管平面位置、高程等参数计算出来的钻孔轨迹，向前钻导向孔，至下一个工作坑；在导向孔出口处，将钻孔钻头换成挤压式出土扩孔钻头，向回拉扩大钻孔孔径，依次多级扩孔，至可容纳预定管道外径后，将管道头部吊人工作坑内导向孔口，使用钻机将管线牵引回工作坑导向孔进口，完成铺设管道施工。     

多轴转向驱动桥转向锁止拉杆铰点位置的优化设计

开发了一种工程机械专用车辆,驱动型式为6×6,全轮转向。其2、3桥采用同步液压转向,且配有转向锁止机构。理论上,转向锁止拉杆被固定后,车辆在水平路面上行驶时各点相对静止,但实际路面总有凸凹之处,会引起超静定问题的发生,从而加剧了轮胎的磨损。为了延长轮胎的使用寿命,初步确定将轮胎与地面间的附加滑移量限制在0.2mm以内。探讨了各推力杆作上下平移或者左右移动时,驱动轴在跳动过程中这些因素对轮胎产生附加摆角的影响程度。优化结果表明,即使跳动量达到100mm,轮胎与地面的最大附加滑移量也仅为0.105mm,达到了预期的优化目标。     

铁路工程建设水土流失预测研究

随着铁路建设步伐的加快,铁路建设过程中引起的水土流失问题日益受到重视,以包兰线包头至惠农段电气化改造工程为研究对象,分析了沿线水土流失形式,确定了流失量,并对预测结果进行了总结。