汽车侧翻和滚翻事故建模研究

分析汽车在侧翻和滚翻过程中的受力状态和轮胎或车身与路面的相互作用方式,建立汽车侧翻和滚翻的运动学和动力学模型,揭示汽车临界侧翻碰撞力与持续作用时间等参数的关系,推导侧翻车辆侧向速度的范围,确定滚筒模型中关键参数的选取方法。事故案例表明模型在实际应用中效果良好、定量准确、直观性强。     

基于GRNN神经网络的长江干线港口集装箱吞吐量预测

在长江集装箱货源市场调查分析的基础上,根据长江干线集装箱发展形势,结合长江干线港口发展情况及历年数据调查,考虑影响港口吞吐量预测的复杂因素,运用GRNN神经网络的优点,构建预测模型。预测结果证明,该模型在应用中是有效的,且当样本数据短缺时,预测效果也较佳。     

What drives the drivers? Predicting turnover intentions in the Belgian bus and coach industry

The bus industry is characterized by demanding jobs and high turnover rates. In this study we gather essential insights that can help companies and industry-level policy makers increase the attractiveness of the profession and design effective retention policies. We compare the factors that induce Belgian drivers to leave their current organization with those inducing them to leave the industry. Key factors increasing the likelihood to consider quitting the company are a negative work-life balance, a lack of social support and a temporary contract. Dominant factors to consider quitting the bus driver profession are a lack of fulfillment, a demanding job environment and a negative work-life balance.     

考虑动车组周转和到发线运用的高速铁路列车运行图优化方法

以列车在车站的作业时间、动车组在终点站的接续时间和车站到发线数量为约束条件,以列车旅行时间和动车组接续时间最小化为目标函数,建立高速铁路列车运行图综合优化模型.模型求解算法主要采用了4种关键技术:以定序列车运行图优化方法化解列车作业时间冲突,以交换列车到发顺序化解到发线冲突,通过保持到发线运用紧张时段的列车到发顺序防止产生新的到发线冲突,运用匈牙利算法求解以动车组最小接续时间为目标的动车组周转方案.算例分析表明,运用给出的模型和算法能够达到整体优化高速铁路列车运行图的目的.     

国民生产总值年增长对货运周转量增长间关系分析

随着国民经济的发展，货运周转量与国民生产总值呈上升趋势。通常情况下，宏观经济时间序列都存在着一定的自相关性，用一般的线性统计回归无法对两者关系进行准确的研究。介绍了协整以及格兰杰因果检验，对中国货运周转量增量和GDP增量2个时间序列为对象进行实证，证明了它们之间存在着稳定的联动关系。     

Promoting carsharing attractiveness and efficiency: An exploratory analysis

Carsharing has grown significantly over recent years. Understanding factors related to the usage and turnover rate of shared cars will help promote the growth of carsharing programs. This study sets station-based shared car booking requests and turnover rates as learning objectives, by which generalized additive mixed models are employed to examine various effects. The results are: (1) stations with more parking spaces, longer business hours and fewer nearby stations are likely to receive more booking requests and have a higher turnover rate; (2) an area with a higher population density, a higher percentage of adults, a higher percentage of males, a greater road density, or more mixed land use is associated with more car usage and a higher turnover rate; (3) stations nearby transit hubs, colleges, and shopping centers attract more shared car users; (4) shared cars are often oversupplied at transit hubs; (5) both transit proximity and housing price present high degrees of nonlinearity in relation to shared car usage and turnover rates. Findings provide evidence for optimizing the usage and efficiency of carsharing programs: carsharing companies should identify underserved areas to initiate new businesses; carsharing seems more competitive in a distance to a bus stop between 1.2 km and 2.4 km, and carsharing is more effectively served in areas with constraints in accessing metro services; carsharing should be optimally discouraged at transit hubs to avoid the oversupply of shared cars; local authorities should develop a location-based and geographically differentiated quota in managing carsharing programs.     

基于改进时间序列法的全社会货物周转量预测

将模糊数学概念加入到时间序列预测方法中,得到了基于改进时间序列法的全社会货物周转量的预测模型,并据此预测了2006年的全社会货物周转量。     

超百米高墩的滑升架翻转模板施工工艺

文章通过介绍新寨河特大桥主跨高墩的滑升架翻转模板施工方法,阐述了滑升架翻转模板施工工艺在高墩施工中的应用和技术特点。并通过与其他高墩施工工艺的对比,评价了滑升架翻转模板施工工艺的适用性、经济性和安全性。     

美国Rule B扣押令和Turnover命令的最新发展动态及评析

Rule B扣押令和Turnover命令一直是美国法律中独特且有效的保全债权人利益的两把利剑。2009年10月和6月,美国法院对Jaldhi案和Koehler案的判决,备受世人的注目。本文即从这两个案例入手探讨美国RuleB扣押令和Turnover命令的最新发展动态并进行评析。     

CIPP树脂软管翻转内衬非开挖修复技术应用

阐述了国内外管道非开挖技术的现状，着重介绍了CIPP树脂软管翻转内衬非开挖修复技术的原理、工序、技术特点及经济指标，论述了该方法的应用前景和需要探讨的问题。