The future of road safety: A worldwide perspective

Estimates by the World Health Organization suggest that, on a yearly basis, road crashes kill 1.25 million people—nearly 3400 road fatalities per day—and injure up to 50 million. Traffic injuries are not equally spread over the world, however; some countries are hit harder than others, and the chance of being killed in a road crash depends on where one lives. Almost 90% of all traffic casualties occur in low- and middle-income countries (LMIC). Globally, the number of fatalities per 100,000 population (mortality rate) ranges from less than 3 to almost 40. The rate is less than 9 in high-income countries (HIC) but averages around 20 in LMIC, with the African region demonstrating the highest rate (26.6). While road safety trends have been positive in HIC over the last few decades, trends in LMIC are not telling a positive story: road fatalities are expected to increase to almost 2 million road fatalities per year by 2020.The United Nations has adopted several resolutions on road safety and proposes actions to tackle the global road safety crisis. Considering the current level of road safety to be unacceptable, the UN has taken several initiatives. One effort, the Decade of Action for Road Safety 2011–2020, has generated substantial activity around the world over the last couple of years. Furthermore, it is very encouraging that the UN included road safety in the Sustainable Development Goals that it laid out in September 2015. Road safety is part of the public health agenda and the urban development agenda. Measured in “real actions,” however, the responses so far from the overall global community and individual countries do not suggest that we are already on the right track to bringing down the death toll on roads.The future of road safety is uncertain and definitely not the same for all regions of the world. Countries with a mature road safety approach and an ambition to make further progress are expected to move in the direction of a pro-active approach: a Safe System approach. It is reported that many LMIC, meanwhile, are on the brink of designing road safety strategies and implementing action plans. The international community is willing to support LMIC, but LMIC cannot simply copy successful HIC strategies because local circumstances differ. The principles of successful HIC strategies are applicable, but the priorities and action plans should take root in and align with local conditions.     

市政工程 BIM 技术应用关键影响因素分析及对策

理论研究表明工程建设全生命周期内的应用能使BIM的实施效果达到最佳，然而目前市政工程领域BIM应用仍然局限于某个阶段层面上的实践，其推广也存在诸多障碍。通过分析总结国内市政工程行业BIM发展和应用现状，梳理出现阶段所面临的障碍及相关因素，然后通过DEMATEL法确定各因素的重要程度，并提出相应的解决措施，以期加快市政工程领域BIM技术应用地推广。     

高速铁路路桥过渡段地基沉降测试与预测方法研究

以津秦客运专线路桥过渡段路基沉降测试为例,利用BP神经网络方法和灰色系统法研究了路桥过渡段沉降预测问题。计算实例表明,神经网络法和灰色系统法短期沉降预测结果比较准确,简便易行,因而具有广泛的工程实用价值和应用前景。     

泥石流作用下桥墩的动力响应分析

由于部分山区桥梁跨越发育冲沟,会受到泥石流的冲击作用,基于桥梁构件能力保护原则,对泥石流作用下桥梁动力响应分析的研究就显得尤为重要。应用有限元动态接触方法对碰撞过程进行数值模拟,选取某高速公路30 m实心T墩建立三维实体有限元模型,分析其在泥石流作用下的动力响应情况。研究表明,在泥石流冲击作用下,块石与桥墩接触区及下部构件连接处应力较大,墩顶位移随上部荷载压力增大而不断减小,即设计应考虑分别提高桥墩的承载能力及其构件连接处的变形能力。     

高等级自动驾驶汽车虚拟测试：研究进展与前沿

安全性测试是高等级自动驾驶汽车（Highly Automated Vehicles，HAV，指具备L3级及以上能力的自动驾驶汽车）规模化应用的基本保障。鉴于HAV测试对象与测试标准的变革，传统基于里程的车辆测试方法论不再适用，场景化虚拟测试正成为验证HAV安全性的核心方法。基于与国内外多家HAV研发机构开展虚拟测试合作的基础上，针对测试场景、测试工具和测试方法等方面的技术难点和学术问题进行汇总、归纳和分析。测试场景方面，围绕场景覆盖度的要求，需重点关注测试场景自主划分、自动化仿真生成和未知高风险场景搜寻等理论方法。测试工具方面，在构建HAV自动驾驶系统“环境感知-规划决策-运动执行”一体化仿真工具的基础上，需研究支撑测试场景生成、驾驶行为双向交互和多传感器物理模型融合的高可信仿真技术。测试方法方面，针对海量测试场景、HAV驾驶能力非单调变化等特征，亟待开展覆盖度驱动型测试方法、加速测试方法和多目标测试与评估等的研究。此外，在上述研究挑战的基础上，面向HAV虚拟测试自动化、快速化、一体化和协同化的应用需求，提出HAV虚拟测试仿真即服务（Simulation as a Service，SAAS）的系统架构，并进一步明确HAV安全性诊断分析、系统自主优化训练和面向系统快速迭代升级的测试方法等SAAS重点研究需求。     

基于振动法检测预应力混凝土梁有效应力的实验研究及有限元分析

在已建的预应力结构中,结构当前的应力检测一直是较难解决的问题。文中利用振动法研究无粘结预应力混凝土梁的振动特性,通过理论分析和实验研究发现,预应力改变了混凝土梁的有效刚度,从而改变了预应力混凝土梁的振动频率。因此可以通过振动频率值反推得到梁的有效应力。通过实验测试和有限元计算得到了预应力混凝土梁在不同预应力作用下的振动频率值,二者的结果吻合较好。研究表明,振动法可以用来检测无粘结预应力混凝土梁的有效应力,为结构的有效应力检测提供了一条参考途径。     

货车后下部防护装置强度的试验方法研究

分析我国货车后下部防护装置标准的强度试验方法与国外法规的差异,并通过仿真分析对比货车后下部防护装置在静态加载、壁障碰撞和车辆追尾下的变形特性、吸能效果及其差异性,提出国标中存在的一些问题及修改建议。     

Fast direction of arrival algorithm based on vector-sensor arrays using wideband sources

An acoustic vector sensor （AVS） can capture more information than a conventional acoustic pressure sensor （APS）. As a result, more output channels are required when multiple AVS are formed into arrays, making processing the data stream computationally intense. This paper proposes a new algorithm based on the propagator method for wideband coherent sources that eliminates eigen-decomposition in order to reduce the computational burden. Data from simulations and lake trials showed that the new algorithm is valid： it resolves coherent sources, breaks left/right ambiguity, and allows inter element spacing to exceed a half-wavelength.     

边界条件对吊索索力估算的影响

从Bernoulli—Euler理论出发，推导了吊索在一般边界条件下的自由振动频率方程和索力的解析表达式。分析了边界条件对吊索自振频率的影响，并与有限元结果进行了比较。结果表明，边界条件对吊索索力估算的影响不可忽略。     

中国管理者的方法特征分析

中华传统文化、中国古代哲学思想对中国管理哲学的构建具有广泛而深刻的影响。本文拟对管理之世界观、管理之规律、管理之道、管理之价值观等涉及中国管理哲学的几个重要问题进行简述,并提出合理化建议与对策。