How much are electric vehicles driven?

The prospect for electric vehicles as a climate change solution hinges on their ability to reduce gasoline consumption. But this depends on how many miles electric vehicles are driven and on how many miles would have otherwise been driven in gasoline-powered vehicles. Using newly-available U.S. nationally representative data, this paper finds that electric vehicles are driven considerably fewer miles per year on average than gasoline-powered vehicles. The difference is highly statistically significant and holds for both all-electric and plug-in hybrid vehicles, for both single- and multiple-vehicle households, and both inside and outside California. The paper discusses potential explanations and policy implications. Overall, the evidence suggests that today’s electric vehicles imply smaller environmental benefits than previously believed.     

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。     

一种镀锌板生产线电气传动控制系统

介绍了镀锌板生产线的工艺流程及其对电气传动的要求，采用PLC对镀锌板生产线的张力和带速进行协调控制，对电气传动控制系统的活套带重补偿和控制算法作了论述。本系统在实际使用中可靠性高，经济效益好，是一种适用的镀锌板生产线电气传动控制系统。     

基于杜邦分析法的格力电器偿债能力分析

论文通过分析格力电器偿债能力,发现主要的几个问题是流动负债和现金比率过高、资本结构风险过高、财务杠杆过高。论文提出了应对这些问题的一些对策和看法,主要是利用充足的现金发展多元化产品、对资本结构进行合理改变和对财务杠杆进行适当调整。     

电力企业物资管理存贮模型应用研究

从存贮论的角度,结合电力企业物资管理的特点与电力系统物资管理本身的特殊性,提出了电力集团物资管理存贮模型,包括最优采购策略和最优存贮策略,从内外两个方面对物资管理存贮过程进行了模型的分析。     

油井采出液处理效果分析及改进措施研究

通过对油站和污水站的化学成分分析，找出了电脱水器跳闸的原因：由于污水中的一些成分导致腐蚀，腐蚀产生的硫化铁和铁颗粒，随着油水混合液在管线中运移，在电脱水器上越积越厚，致使电脱水器上导电率增高，电脱水器跳闸。提出了改善注入水水质，减缓腐蚀的有利措施。     

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.     

Rural electrification and groundwater pumps in India: Evidence from the 1982–1999 period

India's groundwater extraction is heavily dependent on diesel pumps, and one reason is the lack of reliable power supply. The widespread use of diesel pumps is an economic problem due to the inefficiency and high cost of said pumps. Could rural electrification improve the situation? We estimate the relationship between village electrification and the counts of electric and diesel pumps in India, 1982–1999. We find that, in addition to increasing the number of electric pumps, rural electrification also greatly increases the number of diesel pumps. While initially surprising, these results make sense in an environment characterized by frequent power outages and constant quality problems. If rural electrification increases the number of electric pumps and promotes irrigated agriculture, the demand for diesel pumps also grows because many farmers need a reliable pump that does not depend on electricity. Without improvements in the supply of electricity through rational power sector reforms, India cannot stop the spread of diesel pumps through rural electrification. For energy and development economists, the results are novel because previous econometric work has largely focused on industrial uses of power.     

Dually sustainable urban mobility option: Shared-taxi operations with electric vehicles

Electric vehicles (EVs) are energy efficient and often presented as a zero-emission transport mode to achieve long-term decarbonization visions in the transport sector. The implementation of a sustainable transportation environment through EV utilization, however, requires the addressing of certain cost and environmental concerns such as limited driving range and battery-charging issues before its full potential can be realized. Nevertheless, a specific type of use of EVs, namely in taxi services, may elicit positive public opinion, as it promises a commitment toward sustainability in urban life. In light of this, this study proposes an integrated approach that combines EV operation with a conceptual design for shared-ride taxi services. As some productivity loss may be naturally expected due to the time spent in charging, it is important to look at whether such performance loss from the passenger and system standpoints can be offset with ingenuity in operational design. In this study, an EV taxi charge-replenishing scheme that can be coupled with a real-time taxi-dispatch algorithm is designed. The proposed EV charging schemes for taxi services are studied via simulations and the effects of the limited driving range and battery-charging details are examined from a system performance viewpoint. The simulation study also reveals illustrative results on the impact of the EV taxi fleet's operation on the charging system. Next, a real-time shared-taxi operation scheme that allows ride sharing with other passengers is proposed to maximize the operational efficiency. The simulation results suggest that the shared-taxi concept can be a viable option to improve on the limitations caused by EV operation. In addition, the importance of projected charging demands and queue delays at different charging locations are also addressed. Some limitations and a future research agenda are also discussed.     

Pareto efficient allocation of an in-motion wireless charging infrastructure for electric vehicles in a multipath network

Electric vehicles (EV) use an eco-friendly technology that limits the greenhouse gas emissions of the transport sector, but the limited battery capacity and the density of the battery are the major barriers to the widespread adoption of EV. To mitigate this, a good method seems to be the innovative wireless charging technology called ‘On-Line EV (OLEV)’, which is a contactless electric power transfer technology. This EV technology has the potential to charge the vehicle’s battery dynamically while the vehicle is in motion. This system helps to reduce not only the size of the battery but also its cost, and it also contributes to extending the driving range before the EV has to stop. The high cost of this technology requires an optimal location of the infrastructure along the route. For this reason, the objective of this paper is to study the problem of the location of the wireless charging infrastructure in a transport network composed of multiple routes between the origin and the destination. To find a strategic solution to this problem, we first and foremost propose a nonlinear integer programming solution to reach a compromise between the cost of the battery, which is related to its capacity, and the cost of installing the power transmitters, while maintaining the quality of the vehicle’s routing. Second, we adapt the multi-objective particle swarm optimization (MPSO) approach to our problem, as the particles were robust in solving nonlinear optimization problems. Since we have a multi-objective problem with two binary variables, we combine the binary and discrete versions of the particle swarm optimization approach with the multi-objective one. The port of Le Havre is presented as a case study to illustrate the proposed methodology. The results are analyzed and discussed in order to point out the efficiency of our resolution method.