汽车零部件入厂物流优化问题研究现状与趋势

汽车零部件入厂物流优化问题一直是汽车物流研究领域的难点和热点。由于零部件入厂物流在总物流成本中的较大占比,所以至今以来国内外学者不断提出多种汽车零部件入厂物流优化问题和解决方法以降低物流成本费用。为了进一步梳理国内外研究现状,对取货模式分类、管理、运作、优化等入厂物流取货模式问题进行了总结分析,并重点介绍了当下的热点取货模式——循环取货(Milk-run)。然后从需求拆分、成本目标优化等角度对车辆路径优化进行较为全面的综述,最后对本领域一些新的研究方向进行了展望。     

基于高分辨率遥感影像的福州城区建筑用地变化动态监测

利用2006年DMC和2008年UCD两期高分辨率的正射航空遥感影像,对福州市城区建筑用地变化情况进行监测。提取并分析了福州市城区建筑用地变化的特征和规律。结果表明,近两年仓山区建筑用地面积变化最大,增长速度最快;福州市城区建筑用地变化的最大特点是新建建筑用地面积明显大于改扩建建筑用地面积;福州市中心城区逐渐往仓山区方向扩展。     

Socially optimal replacement of conventional with electric vehicles for the US household fleet

In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage data sets that represent US household driving patterns, as well as the automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. Faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.     

视频智能监控检测道路拥挤度方法

近年来，视频监控系统已经广泛应用于道路交通管控中。本文通过检测移动物体的图像序列估算交通拥挤度。该算法是通过拥挤度估算模型计算单位时间内检测移动物体数量，得到实时的交通信息。本文应用MATLAB实现了这一估算方法，并在实际道路测试验证了该计算方法的可靠性。     

Knowledge,beliefs and attitudes of squash venue operators relating to use of protective eyewear

Sports venues are in a position to potentially influence the safety practices of their patrons. This study examined the knowledge, beliefs and attitudes of venue operators that could influence the use of protective eyewear by squash players. A 50% random sample of all private and public squash venues affiliated with the Victorian Squash Federation in metropolitan Melbourne was selected. Face-to-face interviews were conducted with 15 squash venue operators during August 2001. Interviews were transcribed and content and thematic analyses were performed. The content of the interviews covered five topics: (1) overall injury risk perception, (2) eye injury occurrence, (3) knowledge, behaviors, attitudes and beliefs associated with protective eyewear, (4) compulsory protective eyewear and (5) availability of protective eyewear at venues. Venue operators were mainly concerned with the severe nature of eye injuries, rather than the relatively low incidence of these injuries. Some venue operators believed that players should wear any eyewear, rather than none at all, and believed that more players should use protective eyewear. Generally, they did not believe that players with higher levels of experience and expertise needed to wear protective eyewear when playing. Only six venues had at least one type of eyewear available for players to hire or borrow or to purchase. Operators expressed a desire to be informed about correct protective eyewear. Appropriate protective eyewear is not readily available at squash venues. Better-informed venue operators may be more likely to provide suitable protective eyewear.     

A hybrid population heuristic for the heterogeneous vehicle routing problems

The heterogeneous vehicle routing problem (HVRP) plays an important role in supply chain logistics. Two variants of HVRP are treated in this paper: one with fixed and variable costs (HVRPFD), and the other with only variable cost (HVRPD). A hybrid population heuristic that is able to solve both variants is proposed, in which a population of solutions are progressively evolved by crossovers and local searches. Computational results on a set of eight benchmark test problems from literature show that the proposed heuristic produces excellent solutions in short computing times.     

车辆修理集中化布局的双层规划模型研究

在对车辆修理点布局问题分析的基础上,以规划期内修理点的改扩建费用、运营费用和运输费用之和最小为目标建立上层模型,以运输费用最小为目标建立下层模型,以此建立了车辆修理点布局的双层规划优化模型,并给出了相应的求解算法。模型具有较好的适用性和实用性,为铁路车辆修理点的进一步优化调整奠定了较好的理论基础。     

汽车节能和排放环保的现状与发展趋势

文章介绍了由于计算机精确控制的、采用多气阀、高压直喷、稀薄燃烧等新技术的汽车发动机正在普及,现代电子控制装置在发动机上已全面应用,由此带来了油耗降低、排放污染下降显著的效果,并指出新型清洁能源车辆逐步走向实用,其相应的社会配套设施将形成一系列大有可为的全新行业。     

中美日电动汽车发展趋势及特点分析

世界范围内,电动汽车产业正处于快速成长期。中国、美国、日本通过政策机制、技术研发、市场培育等一系列措施推动,在全球电动汽车产业格局中占据了重要位置。在深入分析美国、日本电动汽车发展特点和经验的基础上,对我国电动汽车发展的比较优势进行了阐述,进而分析了在经济全球化环境中,相对美国、日本,我国在发挥产业比较优势时应关注的重点问题。     

对修订后的GB17930-2011《车用汽油》标准的研究

通过对GB19730---2011《车用汽油》标准的解读,解析了标准的修订内容,指出了第Ⅲ与第Ⅳ阶段汽油技术指标的主要差异;阐述了标准的颁布缩小了与先进国家在车用汽油技术指标上的差距,为规范和提高我国车用汽油的质量提供了依据;分析了标准的实施对炼油企业汽油的生产及检验带来的影响。