Fuel economy testing of autonomous vehicles

Environmental pollution and energy use in the light-duty transportation sector are currently regulated through fuel economy and emissions standards, which typically assess quantity of pollutants emitted and volume of fuel used per distance driven. In the United States, fuel economy testing consists of a vehicle on a treadmill, while a trained driver follows a fixed drive cycle. By design, the current standardized fuel economy testing system neglects differences in how individuals drive their vehicles on the road. As autonomous vehicle (AV) technology is introduced, more aspects of driving are shifted into functions of decisions made by the vehicle, rather than the human driver. Yet the current fuel economy testing procedure does not have a mechanism to evaluate the impacts of AV technology on fuel economy ratings, and subsequent regulations such as Corporate Average Fuel Economy targets. This paper develops a method to incorporate the impacts of AV technology within the bounds of current fuel economy test, and simulates a range of automated following drive cycles to estimate changes in fuel economy. The results show that AV following algorithms designed without considering efficiency can degrade fuel economy by up to 3%, while efficiency-focused control strategies may equal or slightly exceed the existing EPA fuel economy test results, by up to 10%. This suggests the need for a new near-term approach in fuel economy testing to account for connected and autonomous vehicles. As AV technology improves and adoption increases in the future, a further reimagining of drive cycles and testing is required.     

考虑风险和贡献因素的港口合作收益分配模型

为了有效地激励港口之间实现联盟, 实现港口联盟成员的共赢, 考虑各港口在合作中的贡献及所承担的风险, 根据互惠互利原则、贡献收益相匹配原则和风险收益相匹配原则, 构建一个基于合作博弈的港口收益分配的非线性规划模型, 通过具体算例对模型进行了应用分析。分析结果表明: 由收益分配模型得到的各个港口的收益均高于各个港口单独经营所得到的收益, 各个港口的收益之和等于3个港口联盟体所得到的总收益, 因此, 规划模型能带来较高的经济效益, 并实现经济效益的合理分配。     

共享经济下的停车位系统设计研究

如今汽车数量日渐暴增,现有停车位尽管满足了一部分泊车车主的需要,然而还是存在停车位资源利用紧张的现象,因此有必要提出共享停车位设计理念.建立在共享经济背景下,这一设计措施在保证固定停车位数量的前提下,改善先前停车紧张的状态,其最大的特色是可以使私有停车位共享,以施展停车位的最大价值,从而使私有车位在空闲时,能够直接转化...     

基于Cruise纯电动手动挡汽车的动力性、经济性换挡浅析

为了更加准确的计算纯电动手动挡汽车的动力性、经济性,利用Cruise软件分类搭建模型,优化手动变速器的换挡车速,通过对计算后的数据对比分析,得到更精确的计算结果.     

A scalable non-myopic dynamic dial-a-ride and pricing problem for competitive on-demand mobility systems

We propose a competitive on-demand mobility model using a multi-server queue system under infinite-horizon look-ahead. The proposed approach includes a novel dynamic optimization algorithm which employs a Markov decision process (MDP) and provides opportunities to revolutionize conventional transit services that are plagued by high cost, low ridership, and general inefficiency, particularly in disadvantaged communities and low-income areas. We use this model to study the implications it has for such services and investigate whether it has a distinct cost advantage and operational improvement. We develop a dynamic pricing scheme that utilizes a balking rule that incorporates socially efficient level and the revenue-maximizing price, and an equilibrium-joining threshold obtained by imposing a toll on the customers who join the system. Results of numerical simulations based on actual New York City taxicab data indicate that a competitive on-demand mobility system supported by the proposed model increases the social welfare by up to 37% on average compared to the single-server queuing system. The study offers a novel design scheme and supporting tools for more effective budget/resource allocation, planning, and operation management of flexible transit systems.     

循环经济在港口环境保护工作中的拓展

从"循环经济"理念的拓展入手,分析了港口项目环保工作中涉及"循环经济"的不同层次,提出了港口环境保护工作中"循环经济"的具体落实措施;结合"天津港吹填淤泥造陆实践"等实例,探讨了如何充分发展"循环经济"对港口环境保护工作的促进作用,并对"循环经济"与"港口环境保护"的结合点进行了初步研究。     

Assessment of hybrid‐drive bus fuel savings for Brazilian urban transit

Buses are the main transit mode in Brazil, transporting more than 55 million passengers per day. Most of these vehicles run on diesel oil causing a dependence on oil, extensive greenhouse gas emissions and increasing air pollution in urban areas. In order to improve this situation, options for Brazilian cities include the use of alternative fuels and new propulsion technologies, such as hybrid vehicles. This paper proposes a procedure for evaluating the performance of a recently developed hybrid‐drive technology. A simple procedure is presented to compare hybrid‐drive buses with conventional diesel buses in urban operations, particularly with respect to fuel economy. Next the potential for reducing diesel oil consumption through the use of hybrid‐drive buses is assessed. Field tests carried out by the authors indicate that fuel consumption improvement through the use of hybrid‐drive buses would certainly exceed 20%, resulting in lower fuel costs and carbon dioxide (CO₂) emissions.     

网络审计及其方法的完善

随着电子商务的不断发展,越来越多的信息处理和传递通过网络完成。这使得网络审计成为可能。从网络审计的现状分析及一般程序入手,对如何完善网络审计的方法进行了论述。     

跨坐式单轨交通防雷效益评估分析

采用闪电定位(ADTD)系统监测资料,对重庆轻轨采取防雷保护措施前后人员生命损失风险和经济价值损失风险进行了评估计算。结果表明,跨坐式单轨采取雷电防护措施后,人员生命损失风险减少了96.98%,经济价值损失风险减少97.38%。自重庆轻轨2号线实际运行以来,截止2009年,其5km范围内各站点及区间年均闪电达到了12 862.75次,但由于采取了有效的防雷措施,未发生一起雷击事故。     

来宾服务区拓展商贸物流功能探析

文章基于点轴型区域经济发展理论、产业关联理论和产业生命周期理论,结合来宾市实际情况与来宾服务区的现有功能,探讨了来宾服务区开发商贸物流功能的必要性与优势。