Projecting travelers into a world of self-driving vehicles: estimating travel behavior implications via a naturalistic experiment

Automated driving technologies are currently penetrating the market, and the coming fully autonomous cars will have far-reaching, yet largely unknown, implications. A critical unknown is the impact on traveler behavior, which in turn impacts sustainability, the economy, and wellbeing. Most behavioral studies, to date, either focus on safety and human factors (driving simulators; test beds), assume travel behavior implications (microsimulators; network analysis), or ask about hypothetical scenarios that are unfamiliar to the subjects (stated preference studies). Here we present a different approach, which is to use a naturalistic experiment to project people into a world of self-driving cars. We mimic potential life with a privately-owned self-driving vehicle by providing 60 h of free chauffeur service for each participating household for use within a 7-day period. We seek to understand the changes in travel behavior as the subjects adjust their travel and activities during the chauffeur week when, as in a self-driving vehicle, they are explicitly relieved of the driving task. In this first pilot application, our sample consisted of 13 subjects from the San Francisco Bay area, drawn from three cohorts: millennials, families, and retirees. We tracked each subject’s travel for 3 weeks (the chauffeur week, 1 week before and 1 week after) and conducted surveys and interviews. During the chauffeur week, we observed sizable increases in vehicle-miles traveled and number of trips, with a more pronounced increase in trips made in the evening and for longer distances and a substantial proportion of “zero-occupancy” vehicle-miles traveled.     

潜艇舱室火灾后的大气监测需求研究

针对潜艇舱室火灾后的大气监测需求,利用材料火灾释放特性试验数据,结合火灾废气组分对人员的健康危害,筛选出火灾后需要重点关注的大气监测组分对象。研究表明,火灾中主要释放5种浓度高且危害性大的气体,分别为二氧化碳、氮氧化物、一氧化碳、氰化氢和二氧化硫。在开展火灾后的大气监测时,可根据火灾类型,从上述5种组分中筛选监测对象,从而在满足人员生存的同时,提高监测效率,降低工作强度,减少应急呼吸系统使用时间。相关研究对我国开展密闭环境火灾后的大气监测方案研究具有指导意义。     

Influence of Light Distribution and Installation Style of Luminaires on Power Consumption and Lighting Effect of Tunnel Lighting北大核心CSCD

Light distribution (LD) and installation style of luminaires affect the utilization factor (UF) of luminaires, and the UF affects the luminaire power and road pavement illuminance and further the power consumption of illu- minating system and the luminous effect of road pavement. An UF model of tunnel lighting was established based on the luminaire LD data and installation parameters, in which four LD styles were adopted. For each LD the parame- ters optimization and simulation were conducted regarding four installation styles, e.g. central style, offset-of-vault style, symmetric style and staggered style. The energy-saving and the lighting effects of each LD and luminaire in- stallation style at the tunnel middle zone were studied. The results show that symmetric luminaire installation is the most energy-saving style and has the best lighting effect than the other three luminaire installation styles; the lighting effect of central luminaire installation is the second best; staggered luminaire installation is the most energy-intensive style and has the worst lighting effect except for some special-shaped LD; waterdrop-shaped LD is the most suitable one along transverse direction of tunnel and applicable to the central, offset-of-vault and symmetric luminaire instal- lation styles; symmetric butterfly-shaped LD is the most suitable one along longitudinal direction of tunnel and appli- cable to the central, offset-of-vault, staggered and symmetric luminaire installation styles; with waterdrop-shaped LD along transverse direction and symmetric butterfly-shaped LD along longitudinal direction, they are suitable for the above four luminaire installation styles, and have better energy-saving and lighting effect; as for the LD with symmetric and oblique curve, it’s better for the profile of oblique luminaire distribution to be comply with that along tunnel transverse direction, and it is suitable for the symmetric and offset-of-vault luminaire installation styles. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

管道仿真技术发展与应用进展

文中从泄漏分析与检测、在线仿真、运行优化与储气调峰方面,分析了国内外管道仿真技术的应用现状。结合当前存在的主要问题,提出应针对仿真软件易用性、高度集成的建模技术和决策支持系统等开展深入研究,以加强对管道的控制及提高管道安全性。     

基于BATMAN的无线自组网系统中乒乓切换的研究

文章主要针对BATMAN协议在多节点移动组网应用场景中所在节点处于各种干扰环境中,导致路由乒乓切换的问题,提出了更新门限阈值的方案.方案的优势就是当路由节点受到干扰来回切换时,提供快速切换制度,提高数据传输效率.通过对无线自组网系统进行测试,表明文章所提出的优化方案能够有效地解决上述问题.     

论应收账款的出质

《物权法》就应收帐款的出质作出了规定,为了更好地实施这一规定,有必要深刻理解应收帐款的内涵、特点与出质的意义,掌握其出质的条件,解决其在出质过程中遇到的实际问题,尽快出台相应的司法解释,完善配套措施,充分发挥应收帐款出质的功能。     

双翼鱼刺型振动模型基础研究

介绍了将平面框架结构简化为双翼鱼刺型振动模型的方法。为了证实该模型的有效性,分别利用反弯点法、D值法、双翼鱼刺型振动模型方法设定多质点系刚度矩阵,对算例结构进行地震响应时程分析;并利用杆系单元有限元的方法,自编电算程序,对算例结构进行地震响应时程分析。最后,对上面几种方法的结果进行比较。结果表明,利用双翼鱼刺型振动模型设定结构刚度矩阵K后计算得出的地震响应值和利用杆系单元有限元方法计算出的结果比较一致。     

内燃机曲轴轴承的润滑状态计算分析

提出分析计算曲轴轴承润滑状态较为精确的方法。介绍了改进的轴心轴迹计算程序的计算模型、原理及方法，并应用该程序对１６２４０柴油机的曲轴轴承进行分析计算。计算结果表明，所得的结果比较精确。     

新冠肺炎疫情下对我国应急交通运输体系的思考及建议

应急交通运输是国家应急管理体系的重要组成部分,但其在新型冠状病毒肺炎疫情防控中暴露出一定程度的不足。为完善我国应急交通运输体系,首先剖析了我国应急交通运输体系存在的问题,即应急物资保障能力不足、重大疫情防控救助措施和手段有待提升、重大疫情联动响应机制尚需优化等;然后,总结了美国和日本应急运输的经验做法;最后,提出完善我国应急交通运输体系的一些政策建议,如进一步完善顶层设计,在交通运输部常设国家应急管理交通运输协调中心,充分发挥交通运输的社会性功能,优化联动响应机制等。     

二维三七桂利嗪胶囊对急性脑缺血的保护作用

目的观察二维三七桂利嗪胶囊对于急性脑缺血的影响。方法ICR小鼠分别用420 mg/kg、210 mg/kg、105 mg/kg的二维三七桂利嗪胶囊灌胃10 d,观察断头后小鼠的喘息时间;SD大鼠分别用292 mg/kg、146 mg/kg、73 mg/kg的二维三七桂利嗪胶囊灌胃10 d,线栓法制备大鼠大脑中动脉栓塞模型,然后进行神经行为指标评分、脑梗死范围测定和病理学观察。结果二维三七桂利嗪胶囊各剂量组均能延长小鼠断头后的喘息时间,缩小局灶性脑缺血大鼠脑梗死范围,改善神经症状,减轻光镜下脑组织缺血性损伤。结论二维三七桂利嗪胶囊对急性脑缺血损伤具有保护作用。