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51.
This paper adds partial household evacuation to the traditional binary evacuate/stay decision. Based on data from a survey of Jacksonville, FL residents after Hurricane Matthew, multinomial (MNL) and random parameter MNL models were developed to determine the influential factors and whether some variables’ effects are more nuanced than prior literature suggests. The random parameter model was preferred to the fixed parameters model. Variables significant in this model included injury concern, certainty about hurricane impact location, age, marital status, family cohesion, and living in mobile or detached homes. Greater injury concern results in lower likelihood of none of the household evacuating and greater likelihood of partial evacuation, but lower likelihood of full household evacuation. Similarly, greater certainty about hurricane impact increased the probability of partial household evacuation but decreased the probability of full evacuation. Respondent age had heterogenous effects; for 85.54% of respondents, additional years of age increased the likelihood of the household staying. Married households had a higher likelihood of staying or evacuating together. Similarly, greater family cohesion was associated with the household remaining together. Living in mobile homes decreased the likelihood that all of the household stays or evacuates and increased the probability of partial household evacuation. Living in a single-family detached home was associated with lower likelihood of all of the household staying or evacuating and a greater likelihood of a partial household evacuation. These findings can inform strategies that influence full or partial household evacuations, material requirements based on these decisions, and ways to reduce family risk. 相似文献
52.
净掘进速率是TBM施工速度的主要评价指标,与围岩物理力学性质、TBM掘进参数之间存在一定相关性。文章以兰州水源地建设工程输水隧洞双护盾TBM施工为背景,基于现场实测数据,选择岩石单轴抗压强度、抗拉强度、变形模量、泊松比、岩石耐磨性CAI值等岩体指标,以及刀盘推力和刀盘转速等掘进参数,进行TBM净掘进速率与有关影响参数之间的单因素相关性分析,得到相应拟合公式;基于TBM净掘进速率与岩体指标、掘进参数之间的相关性,利用多元非线性回归方法建立了TBM净掘进速率预测模型。通过将兰州水源地建设工程输水隧洞实测TBM净掘进速率和预测结果进行对比,验证了TBM净掘进速率预测模型的合理性。研究结果表明:(1)在复杂的多种地质条件下,TBM净掘进速率与岩石单轴抗压强度、抗拉强度、变形模量、岩石耐磨性CAI值、刀盘推力以及刀盘转速呈负相关关系,与泊松比呈正相关关系;(2)干湿状态对岩石耐磨性CAI值有一定影响,饱和状态下岩石耐磨性CAI值与TBM净掘进速率之间的相关性更显著;(3)建立的多元非线性回归预测模型,预测精度较高,可为相似地质条件下TBM净掘进速率估算提供参考。 相似文献
53.
在交通管理和评价时,信号配时对监测评价路口运行状态,评价路口配时方案至关重要.但是,大范围的实时信号配时方案的获取尚缺乏简明有效的途径.本文提出两种基于移动导航数据计算固定配时路口信号配时的方法.第一种方法是在不考虑驾驶员驾驶行为差异性时,得到路口红灯和车均延误的关系模型,从而计算某相位的红灯时长.另外一种方法是基于车辆通过停止线的时间,结合本文提出的上升梯度法,得到某阶段红灯时长.本文通过实际的路口案例计算,将预测结果和已知路口的信号配时比较,表明此方法计算得到的红绿灯时长准确度较高,为后续进行路口运行状态和通行能力研究提供了数据支持. 相似文献
54.
路基长期稳定性是一个综合性的问题,要想通过设计或施工一劳永逸的解决,在技术上是困难的,在经济上也是不适宜的。只有通过对设计、施工、养护三者综合考虑,把握影响路基长期稳定性的关键因素,才能经济、合理地解决该问题,使公路更好地为经济建设服务。 相似文献
55.
Aikaterini Rentziou Reginald R. Souleyrette 《Transportation Research Part A: Policy and Practice》2012,46(3):487-500
Globalization, greenhouse gas emissions and energy concerns, emerging vehicle technologies, and improved statistical modeling capabilities make the present moment an opportune time to revisit aggregate vehicle miles traveled (VMT), energy consumption, and greenhouse gas (GHG) emissions forecasting for passenger transportation. Using panel data for the 48 continental states during the period 1998-2008, the authors develop simultaneous equation models for predicting VMT on different road functional classes and examine how different technological solutions and changes in fuel prices can affect passenger VMT. Moreover, a random coefficient panel data model is developed to estimate the influence of various factors (such as demographics, socioeconomic variables, fuel tax, and capacity) on the total amount of passenger VMT in the United States. To assess the influence of each significant factor on VMT, elasticities are estimated. Further, the authors investigate the effect of different policies governing fuel tax and population density on future energy consumption and GHG emissions. The presented methodology and estimation results can assist transportation planners and policy-makers in determining future energy and transportation infrastructure investment needs. 相似文献
56.
57.
Lei Xu 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(3):427-448
The vehicle–track coupled system has a random nature in the time–space domain. This paper proposes a computational model to analyse the temporal–spatial stochastic vibrations of vehicle–track systems, where the vehicle–track system is divided into a vehicle subsystem, track subsystem, and interfacial subsystem between the wheel and rail. In this model, the time-varying randomicity of dynamical parameters of the vehicle system, correlation, and randomness of the track structural parameters in the time–space joint dimensions, and randomness of the track random irregularities are considered. A probability dimension-reduction method was used to randomly combine different random variables. Furthermore, the probability density evolution method was applied to solve the delivery problem of probabilities between excitation inputs and response outputs. The temporal–spatial stochastic vibrations of the vehicle–track system with different coefficients of variation were studied, in which we assumed that the dynamic parameters obeyed the normal distribution, and the stochastic simulation method of the track random irregularities is probed into. The calculated results from this model are consistent with the actual measured results and physical conceptions. Thus, the temporal–spatial stochastic evolutionary mechanism can be explored, and the limits of dynamic indices can be formulated by using this developed model. 相似文献
58.
依托黄土地区高速公路改扩建桥梁加宽工程,选取一座3孔13 m简支空心板桥,分析新增空心板梁对旧桥原有板梁的影响。基于不同加宽方案对新旧桥空心板梁横向分布系数进行了计算,计算结果表明增加新梁截面刚度可有效降低旧梁横向分布系数。建议采用移旧桥边梁为新桥边梁并且提高新增空心板梁刚度的加宽方案。 相似文献
59.
自锚式斜拉-悬索协作体系桥作为一种全新的结构体系,兼备了自锚式悬索桥和斜拉桥的许多优点,结构体系则更为复杂。结合400m主跨的金州海湾大桥这一实际工程方案,建立了有限元空间分析模型,分析了其在静风荷载作用下的非线性行为,总结了初始攻角、附加攻角等参数及是否考虑缆索系统承受风荷载等对体系的影响规律。 相似文献
60.
韩同群 《湖北汽车工业学院学报》2015,(1):1-5,16
研究了世界范围内柴油机在乘用车领域内的应用现状,阐述了柴油机作为车用动力的优势。根据国内的政策环境与市场环境,分析了排放法规、柴油品质对市场的影响。根据对柴油轿车的性能要求,包括振动和噪声、排放等,分析了更适合我国轿车柴油机发展的技术路线,并重点对若干关键技术和难点进行了剖析。柴油机技术进步和市场化应用表明,柴油轿车在我国具有广阔的应用前景,政府和企业应做好政策和技术上的准备。 相似文献