风景区交通系统组织优化策略——以扬州市蜀冈-瘦西湖风景区为例

扬州市作为历史文化名城,有着丰富的旅游资源。蜀冈-瘦西湖风景区作为扬州市代表性旅游景点,紧邻老城区,交通现状与发展特征具有一定的代表意义,日益增长的旅游需求与传统路网格局之间的矛盾亟待解决,提出从陆地交通、水上交通两方面统筹安排、合理组织景区交通问题,并分别对区域交通、外部交通、内部交通、水上旅游线路、水上码头设置和水陆旅游衔接等进行了优化。同时,在充分保护风景区的基础上,提出了交通需求管理措施。     

镀锌钢板电阻点焊电极的深冷处理工艺研究

提出了一种新的提高镀锌钢板点焊电极寿命的方法,即深冷处理工艺。对深冷处理电极及未深冷处理电极点焊寿命进行了试验,并比较了不同深冷处理工艺对电极寿命的影响。试验结果表明:深冷处理可显著提高镀锌钢板点焊电极的工作寿命,不同的深冷处理工艺对电极寿命影响不同;保冷温度对寿命影响较大,而保冷时间对电极寿命影响较小。介绍了电极深冷处理工艺及深冷处理电极寿命试验过程。     

Measuring Truck Travel Time Reliability Using Truck Probe GPS Data

Truck probe data collected by global positioning system (GPS) devices has gained increased attention as a source of truck mobility data, including measuring truck travel time reliability. Most reliability studies that apply GPS data are based on travel time observations retrieved from GPS data. The major challenges to using GPS data are small, nonrandom observation sets and low reading frequency. In contrast, using GPS spot speed (instantaneous speed recorded by GPS devices) directly can address these concerns. However, a recently introduced GPS spot-speed-based reliability metric that uses speed distribution does not provide a numerical value that would allow for a quantitative evaluation. In light of this, the research described in this article improves the current GPS spot speed distribution-based reliability approach by calculating the speed distribution coefficient of variation. An empirical investigation of truck travel time reliability on Interstate 5 in Seattle, WA, is performed. In addition, correlations are provided between the improved approach and a number of commonly used reliability measures. The reliability measures are not highly correlated, demonstrating that different measures provide different conclusions for the same underlying data and traffic conditions. The advantages and disadvantages of each measure are discussed and recommendations of the appropriate measures for different applications are presented.     

汽车车身钣金件点焊连接界面特性与建模

本文分别选用四种类型单元建立车身钣金件点焊模型，并将数值解与试验模态分析结果对比，评价各方法之优劣，提出了由大量点焊连接的车身结构模新方法。实践证明该法是有效的。     

A data fusion approach for real-time traffic state estimation in urban signalized links

Real-time estimation of the traffic state in urban signalized links is valuable information for modern traffic control and management. In recent years, with the development of in-vehicle and communication technologies, connected vehicle data has been increasingly used in literature and practice. In this work, a novel data fusion approach is proposed for the high-resolution (second-by-second) estimation of queue length, vehicle accumulation, and outflow in urban signalized links. Required data includes input flow from a fixed detector at the upstream end of the link as well as location and speed of the connected vehicles. A probability-based approach is derived to compensate the error associated with low penetration rates while estimating the queue tail location, which renders the proposed methodology more robust to varying penetration rates of connected vehicles. A well-defined nonlinear function based on traffic flow theory is developed to attain the number of vehicles inside the queue based on queue tail location and average speed of connected vehicles. The overall scheme is thoroughly tested and demonstrated in a realistic microscopic simulation environment for three types of links with different penetration rates of connected vehicles. In order to test the efficiency of the proposed methodology in case that data are available at higher sampling times, the estimation procedure is also demonstrated for different time resolutions. The results demonstrate the efficiency and accuracy of the approach for high-resolution estimation, even in the presence of measurement noise.     

重卡车车外盲区监测系统的方案设计与实现

重卡车由于车身高、体积大、轴距长,在转弯、倒车时驾驶员视线会产生盲区,车外盲区监测系统有效消除了驾驶员的视觉盲区,特别是消除了右前侧、右后侧、后方等重点部位盲区,而且雷达探头可实现对接近车辆两侧危险区域内障碍物的自动报警,大大提供了重卡车的行车安全性。     

基于车辆轴型分类的公路货运车辆运营成本研究

针对目前公路货运车辆运营成本分析中车型分类与装载量确定方法的不足,提出了基于车辆轴型分类的运营成本研究模式,在按轴型划分的交通量和轴载调查的基础上通过建立轴载分布模型确定分析车型与其装载量,并根据政府政策和车辆装载量的影响程度分类统计分析车型的单位运营成本。使用安徽省调查数据推导出了公路货运车辆运营成本与装载量之间的经验公式。结果表明:该省公路货运车辆的平均单位运营成本在0.253-0.756元/t·km之间,与市场运价基本一致。     

点焊拼接板的冲压技术特点和发展

点焊拼接板是一种高效率、低成本的拼焊板,在汽车制造业领域具有广阔的应用前景。系统地介绍了点焊拼接板的研究现状和发展前景。通过分析点焊拼接板冲压变形特点,指出点焊拼接板冲压加工技术关键在于了解焊点及其热影响区的冲压变形机理及对其它部位材料变形的影响关系。     

帽型薄壁管件准静态压溃模拟计算中焊点的处理方法

以单帽薄壁管轴向准静态压溃试验为基础，研究了帽型薄壁管准静态压溃有限元分析中焊点的建模方式。在Ls-Dyna平台上系统地分析了不同类型的焊点模型对于单帽结构准静态压溃模拟计算中平均压溃力及变形模式的影响，通过对比模拟结果与试验结果，得出了适用于帽型薄壁管准静态压溃模拟计算的焊点模型。     

现场热再生施工过程中的关键控制点

通过实体工程着重介绍了现场热再生工序的几大控制点,以供现场热再生施工技术人员参考。