Commuting-related fringe benefits in the Netherlands: Interrelationships and company,employee and location characteristics

Mobility management measures taken by firms could potentially result in more sustainable transport choices and hence reduce traffic congestion and emissions. Fringe benefits offered to employees are a means to implement those measures. This paper explores the most common commuting-related fringe benefits currently provided by employers in the Netherlands, namely telework, flextime and allowance types like public transport passes, bicycle contribution, company cars and general financial compensation. By using the Dutch National Time Use Survey (TBO) 2005/2006, interrelationships among fringe benefits and correlations between company, employee, and (home and work) location characteristics and those employee benefits could be investigated. Logistic regressions and Tobit models are used for several estimations indicating the provision and the use of fringe benefits. The results show that relationships among fringe benefits exist, mainly between telework and flextime, but also between those flexible work arrangements and some types of commuting allowance. Furthermore, numerous job, person and geographical variables affect the probability of receiving and using the fringe benefits. For example, in the non-profit and the public sector sustainable commuting benefits are more often provided, the use of fringe benefits is strongly influenced by household composition and several allowance types show a significant correlation with the number of cars in the household. Moreover, firm location, in particular firm density, is highly related to mobility management measures taken by firms.     

以案例分析为导向的二手车鉴定与评估

随着我国汽车消费的普及,我国二手车市场呈现出迅速的发展势头,二手车交易形态由集中交易模式逐渐向多元化主体经营模式过渡,新老经营主体通过各种途径不断提升服务质量以适应不断变化的市场。而我国二手车市场还存在一些不规范的问题,使得一些不合格的二手车流入市场,这样不但损坏整个行业的名誉也给消费者带来了安全隐患。通过规范的评估流程可以很大程度的规范市场行为,提高人们对二手车行业的信赖度。     

赛车轮毂多功能集成化设计新方法

由于传统制造工艺在复杂曲面和集成化加工的局限性,导致方程式赛车轮毂的多功能集成化一直被制约,以至于传统赛车轮毂总成普遍存在体积硕大、重量大、传动效率低等问题。文章基于集成化设计原则,在保留传统赛车轮毂总成所需功能的前提下,改变赛车外球笼、轮毂、轮辐等的结构以进行集成化设计从而得到多功能集成化赛车轮毂。所获得的集成化赛车轮毂体积重量明显减小且传动效率明显提高,达到了通过集成化以实现轻量化的目标。     

Exploiting floating car data for time-dependent Origin–Destination matrices estimation

The study evaluates the added value generated by estimating dynamic demand matrices by information gathered from Floating Car Data (FCD).

Firstly, adopting a large dataset of FCD collected in Rome, Italy, during May 2010, all the monitored trips on a specific district of the city (Eur district) have been collected and analysed in terms of (i) spatial and temporal distribution; (ii) actual route choices and travel times. The data analysis showed that demand data from FCD are usually not suitable to retrieve directly demand matrices, due to a strong dependence of this information from the penetration rate of the monitoring device. Instead, origin–destination travel times and route choice probabilities from FCD are a much more reliable and powerful information with respect to FCD origin–destination flows, since they represent the traffic conditions and behaviors that vehicles experiment along the path.

Thus, several synthetic experiments have been conducted adopting both travel times and route choice probabilities as additional information, with respect to standard link measurements, in the dynamic demand estimation problem. Results demonstrated the strength and robustness associated to these network based data, while link measurements alone are not able to define the real traffic pattern. Adopting both the information of origin–destination travel times and route choice probabilities during the demand estimation process, the spatial and temporal reliability of the estimated demand matrices consistently increases.     

轿车车门安装件的力学性能分析

国内在轿车车门的设计过程中出现很多问题,尤其是车门铰链、车门安装点等安装件的性能,大大影响了车门的机械性能、声品质。分析车门安装件的性能、提高其力学性能是主机厂十分关注的问题。本文阐述了车门安装件的结构及其性能要求,然后应用计算机辅助分析对车门铰链、车门安装点进行了力学分析。本文的研究方法对于车门安装件的力学分析有参考作用。     

基于传递路径分析的乘用车车内噪声数值模拟

本文利用传递路释分析(TPA)方法对某一新型轿车进行轮胎引起的车内噪声分析,首先运用TPA方法拟合测试数据以求出路面对轮胎的轮心激励值,再将该值加载到CAE模型内进行数值模拟,计算车内噪声。数值模拟计算中发现乘用车后轴对整车噪声的贡献大于前轴,说明需要对乘用车的后轴进行改进;比较数值模拟结果与路面噪声的实际测试数据,发现分析误差可接受,完全可以反映出车辆车内噪声特性,验证了传递路径分析方法在车内噪声分析中的适用性和准确性。     

大车后下部防护装置的设计与仿真验证

为了有效阻挡小车下钻到大车尾部,设计了一款由支撑横杆、主副支架、阻挡梁构成的大车后下部防护装置,通过主副支架在支撑横杆上的缠绕变形吸收碰撞能量。主副支架均斜向后安装,提供一定的纵向支撑力,增加装置整体强度,同时也增加了碰撞接触时间和可变形距离,形成更有效的缓冲。主副支架为最主要强度部件,在LS-DYNA中对其独立加载分析,确定抗变形能力最强的结构形式。在进行的壁障碰撞仿真中,壁障最大减加速度为20 g(g为重力加速度,下同),回弹最大速度为0.9 m·s-1,最大纵向位移为369 mm,各项评价指标均满足GB 11567.2-2001[1]的要求。     

天津市交通指数及其在双限政策评估中的应用

利用出租汽车浮动车大数据研究科学合理且直观易懂的交通指数并动态跟踪城市道路交通运行规律,不仅是中国大城市关注的焦点,更是在天津市机动车限购、限行政策下非常重要的城市交通基础性研究。通过出租汽车车速精度分析、期望车速选取、指数标准化等关键技术研究,提出天津市可应用于宏观交通政策评估和交通规划研究的交通指数。同时,应用交通指数分析双限政策实施前后两年城市交通的运行特征,分别从年、月、日、小时及区域五个方面评估双限政策的实施效果。结果表明,天津市适度超前的机动车限制政策对缓解交通拥堵的效果显著并得到广泛支持。     

一种车辆运输半挂车上的轮桥结构

提供了一种车辆运输半挂车上的新型轮桥结构。所述的车桥为小轮车桥,所述的轮胎为235/75R17.5型无内胎子午线轮胎。这种轮桥结构主要优点为车辆宽度符合国家标准要求,解决了车辆运输半挂车超宽的难题,增加了车辆运输半挂车行驶的通过性、安全性;车轴上方货台面低,后尾爬车跳板坡度小,适合装运车型多。     

某车门碰撞性能分析及结构优化研究

利用有限元分析软件Hypermesh和LS-DYNA建立某SRV白车身车门有限元模型,进行车门有限元碰撞仿真分析.针对该车门侧面抗撞性能差的情况,采用拼焊板对车门外板进行结构改进,提高车门抗撞性能,保证乘员的安全.