Risk aversion,regret aversion and travel choice inertia: an experimental study

This paper presents the results of an experimental study into the role of risk aversion and regret aversion as codeterminants of travel choice inertia. Theoretical results published by Chorus and Dellaert are tested empirically. More specifically, the expectation is tested that when (1) travelers are risk averse, (2) the quality of travel choices is uncertain, and (3) the quality is partially revealed upon usage, travel choice inertia emerges as a learning-based lock-in effect. In addition, this paper studies the role of regret aversion as a possible trigger of travel choice inertia. Analyses are based on data collected in an experiment, where the reward that participants obtain is a function of the outcome of choices they make. Empirical results suggest that the learning-based lock-in effect indeed plays a role in the context of our data. The evidence for the hypothesis that regret aversion triggers inertia is mixed at best.     

转叶式液压舵机若干技术分析

转叶式液压舵机曾经是舵机行业关注的热点,但因如可靠性、操纵性等存在问题而停步不前.经过几十年的研究和积累,对转叶式液压舵机有了新的认识,它的某些关键技术也已获得解决,这对推动转叶式液压舵机的应用和发展是十分有利的.     

地磁与惯性汽车导航系统

介绍汽车内部信息导向行驶系统中地磁与惯性汽车导航系统的构成、原理及应用实例。     

大岩洞大桥平转施工工艺设计

研究目的：桥梁施工方法是桥梁设计时必须考虑的重要因素。平转施工作为一种修建桥梁的有效方法，已经在山区桥梁建设中得到广泛应用。大岩洞大桥主桥采用上承式钢管混凝土劲性骨架箱形拱，平转法施工。为保证施工期间结构安全，需采用合理的工艺设计、控制措施、控制指标和指导性意见。通过总结本桥设计施工经验，可为今后类似桥梁施工提供借鉴。研究结论：对于重达5237t的转体结构，采用混凝土球铰平转施工为国内首次。本文结合工程实例，详细介绍了转体结构构造细节、静力计算、施工控制指标、安全措施。本桥历时9h，劲性骨架平转到位。合拢精度满足设计要求，结构各项指标和设计相符。转体施工过程中，应实时监控结构的应力和变形，采用现场实测数据修正计算模型，以使理论计算和实际相吻合，保证桥梁的安全施工。实践证明了平转施工方法可以有效解决山区桥梁施工的问题。     

海洋市政管线扩散器安装技术研究

通过介绍当前海洋市政管线扩散器的主要构造形式和特点,分析了扩散器安装的施工准备,剖析了海洋市政管线扩散器的主要安装方式。研究总结了当前海洋工程扩散器安装的施工工艺流程,明确了海洋市政管线扩散器安装主要根据扩散器长度、材质及所在海域的海流、涌浪和当地气候等因素选择施工工艺。同时,阐明了一种较为常规、有效的扩散器安装方式——通过陆地分段预制,海上精确定位,借助船舶分段运输、分段起吊和安放,采用旋转法兰实现水下连接。这为海洋市政管线扩散器安装指明了研究方向,也为探索更加安全、快捷的安装方式奠定了基石。     

Sensitivity analysis to assess the influence of the inertial properties of railway vehicle bodies on the vehicle's dynamic behaviour

A sensitivity analysis has been performed to assess the influence of the inertial properties of railway vehicles on their dynamic behaviour. To do this, 216 dynamic simulations were performed modifying, one at a time, the masses, moments of inertia and heights of the centre of gravity of the carbody, the bogie and the wheelset. Three values were assigned to each parameter, corresponding to the percentiles 10, 50 and 90 of a data set stored in a database of railway vehicles. After processing the results of these simulations, the analysed parameters were sorted by increasing influence. It was also found which of these parameters could be estimated with a lesser degree of accuracy for future simulations without appreciably affecting the simulation results. In general terms, it was concluded that the most sensitive inertial properties are the mass and the vertical moment of inertia, and the least sensitive ones the longitudinal and lateral moments of inertia.     

荷兰IHC-S280液压锤的使用与性能

为适应杭州湾大桥水上施工的需要,中港一航局从日本购买一艘700t全旋转式多功能“天威”号工程船舶,该船配备有荷兰制造IHC型号系列液压打桩锤。通过对柴油打桩锤的液压打桩锤打桩动测和打桩能力计算结果分析,荷兰制的S280液压锤性能大大高于柴油锤D125和D128。采用S280锤代替柴油锤打桩,为完成杭州湾东海大桥超长度、大直径桩的施工提供了可靠保证。     

直线电机在轨道车辆运用中的三维分析

从三维方向分析,认为直线电机将原来旋转电机的电磁力,即内力变为了外力,从而给轨道车辆的设计概念带来重大的变化。通过对目前世界上直线电机车辆使用的实际业绩的分析,提出车辆质量可减轻的观点。     

富水性软弱Ⅵ级围岩段隧道开挖支护施工技术

某项目工程地质和水文地质条件复杂,变化明显,尤其是区间隧道围岩级别由Ⅱ级过渡到Ⅵ级,施工方法变化频繁.安全、快速通过富水性软弱Ⅵ级围岩段是隧道施工中的重点和难点.通过分析该段落的具体地质特点,提出相应对策和施工任务;在此基础上,探讨了开挖支护技术施工要点.     

旋挖钻机在软弱地质条件下桩基施工技术的研究

20世纪80年代,我国在地基桩基施工中开始引进国外旋挖钻机施工技术,但公路桥梁桩基在软弱地质中的应用经常出现成孔坍塌、缩孔、倾斜等问题。本文通过钱江通道南接线工程中,对在透水性强的粉砂层和强度低、含水量高淤泥质的软土地质构造复杂的条件下,采用旋挖钻机成孔的施工技术方法,在施工过程中对泥浆选择、施工技术、工艺、质量控制进行研究,解决了旋挖钻机在软弱地质施工中塌孔、缩孔、倾斜的难题,取得了很好的效果。