浅析多媒体技术在车辆工程教学中的应用

随着教育的发展 ,传统的教学方法已不能满足时代的需要 ,亟待运用现代教育技术手段 ,特别是多媒体的教学形式进入课堂 ,以发挥其特有的功能来提高学习效率。本文浅淡了如何在车辆工程教学中运用计算机多媒体的图、文、声、像并茂的特点 ,有效的激发学生的学习兴趣。     

The trade-off between fixed vehicle costs and time-dependent arrival penalties in a routing problem

This paper introduces the vehicle routing problem with soft time windows (VRPSTW) in which problem definition differs from ones previously defined in literature. Branch-and-price approach is employed, resulting in a set partitioning master problem and its new subproblem. Novel techniques are consequently developed to solve this new subproblem. Experimental results report the comparisons of these solution techniques under the branch-and-price framework. The VRPSTW solutions have further been compared to the state-of-the-art literature, signifying the superiority of the VRPSTW on this issue.     

A heuristic approach for the green vehicle routing problem with multiple technologies and partial recharges

This paper presents several heuristics for a variation of the vehicle routing problem in which the transportation fleet is composed of electric vehicles with limited autonomy in need for recharge during their duties. In addition to the routing plan, the amount of energy recharged and the technology used must also be determined. Constructive and local search heuristics are proposed, which are exploited within a non deterministic Simulated Annealing framework. Extensive computational results on varying instances are reported, evaluating the performance of the proposed algorithms and analyzing the distinctive elements of the problem (size, geographical configuration, recharge stations, autonomy, technologies, etc.).     

Combinatorial clock-proxy exchange for carrier collaboration in less than truck load transportation

A carrier collaboration problem in less-than-truck load transportation is considered, where multiple carriers exchange their pickup and delivery requests in order to improve their operational efficiency. We extend the clock-proxy auction proposed by Ausubel et al. (2006) to a combinatorial clock-proxy exchange for the problem. This mechanism combines the price discovery of the clock exchange designed based on Lagrangian relaxation with the efficiency of the proxy exchange determined based on the information observed in the clock phase. Numerical experiments on randomly generated instances demonstrate the necessity of the proxy phase and the effectiveness of the clock-proxy exchange.     

Models for relief routing: Equity, efficiency and efficacy

In humanitarian relief operations, vehicle routing and supply allocation decisions are critically important. Similar routing and allocation decisions are studied for commercial settings where efficiency, in terms of minimizing cost, is the primary objective. Humanitarian relief is complicated by the presence of multiple objectives beyond minimizing cost. Routing and allocation decisions should result in quick and sufficient distribution of relief supplies, with a focus on equitable service to all aid recipients. However, quantifying such goals can be challenging. In this paper, we define and formulate performance metrics in relief distribution. We focus on efficacy (i.e., the extent to which the goals of quick and sufficient distribution are met) and equity (i.e., the extent to which all recipients receive comparable service). We explore how efficiency, efficacy, and equity influence the structure of vehicle routes and the distribution of resources. We identify trends and routing principles for humanitarian relief based on the analytical properties of the resulting problems and a series of computational tests.     

Benefits of in-vehicle consolidation in less than truckload freight transportation operations

Researchers and public agencies have proposed consolidation policies as an alternative to increase truck payload utilization and mitigate externalities produced by freight transportation. Understanding and enhancing the economic mechanisms that lead to freight consolidation can ease the implementation of these strategies, increase profits for shippers and carriers, and reduce freight-related negative externalities. An important mechanism that has recently been studied for cost reduction in the freight industry is combinatorial auctions. In these auctions, a shipper invites a set of carriers to submit bids for freight lane contracts. Carriers can bid for individual lanes or bundles of them according to their operational characteristics. These bids are constructed considering direct shipments (Truckload operations) and several biding advisory models have been proposed for this purpose. However, there are economies of scale that can be achieved if shipments are consolidated inside vehicles, which have not been explored in the construction of competitive bids. This paper investigates such benefits and provides insights on the competitiveness and challenges associated to the development of consolidated bids (suitable for Less-Than-Truckload operations). Consolidated bids are constructed using a multi-commodity one-to-one pickup-and-delivery vehicle routing problem that is solved using a branch-and-price algorithm. The numerical experiment shows that non-consolidated bids are dominated by consolidated bids, which implies that this type of operation can increase the likelihood of a carrier to win auctioned lanes, while increasing its profits margins over truckload companies (non-consolidated bids), and keeping the reported benefits that combinatorial auctions represent for shippers.     

新能源汽车财务与非财务消息对股市影响的多维特征及差异

新能源汽车股市是投资者对公司财务绩效、政策导向、技术水平和发展前景等多方面因素综合反应的结果。将新能源汽车产业相关消息分为"财务"和"非财务"消息,应用事件研究法从"敏感性""、强弱性"和"持续性"三个维度分析了财务与非财务类消息对于新能源汽车股市影响的差异性。结果表明,新能源汽车非财务类消息对于股市表现影响的强度和持续性相对更显著。新能源汽车非财务类消息中的政策、市场消息对于股市表现影响的敏感性要高于技术消息,政策、技术消息对于股市表现影响的强度明显高于市场消息,技术消息对于股市表现影响的持续性明显优于政策和市场类消息。新能源汽车产业的政策扶持不应仅仅关注现阶段新能源汽车制造商的财务指标,更应高度关注新能源汽车制造商的创新能力。制造商要进一步加大新能源汽车的研发投入,通过资本市场的合理融资促进新能源汽车技术创新和长期盈利能力提升。     

浅析我国报废汽车的回收与再利用

在汽车产业高速发展的今天,如何有效地回收报废汽车,并对其进行再利用,降低环境污染,已经成为一项严峻的社会问题。本文针对我国报废汽车回收现状、相关政策和标准进行了初步的分析,并借鉴欧洲相关法规和指令,对如何进一步提升我国报废汽车产业回收和再利用的效率,提出一些参考建议？     

高速铁路动车组检修资源布局优化研究

高速铁路网的日趋完善,高速列车开行数量的进一步增加,对高速铁路动车组检修资源布局提出新的要求。为合理优化动车组检修资源布局,提高动车组检修效率,在分析我国动车段和动车运用所管理模式及布局方案的基础上,将动车组检修资源布局优化问题转化为基于多基地车辆路径运用的基地选址问题,基于"备选运用所-运输需求-动车组运用"间的关联关系构建动车组运用检修接续网络,建立动车组检修资源布局优化模型。以某区域的铁路网为例,利用近远期规划优化动车组检修资源布局,验证模型有效性,为今后动车组检修资源布局优化提供参考。     

后补贴时代中国新能源汽车产业发展研究

2019年3月,四部委公布新一轮新能源汽车补贴政策,相比2018年标准平均退坡超50%。自政策公布之后,国内新能源汽车市场环境发生巨变,新能源汽车销量增长明显放缓,部分新能源汽车及零部件企业经营困难甚至倒闭,加之以特斯拉为首的外资新能源汽车企业陆续在华设厂投产,使国内新能源汽车市场竞争加剧,下行压力增大,新能源汽车产业正式进入后补贴时代,在此背景下,需要政府部门、相关企业重新评估市场现状,制定新的新能源汽车产业发展战略和路径,推动产业持续健康地发展。