甩箱模式下考虑多箱型任务组合的集卡调度优化

针对甩箱模式下港口堆场与内陆腹地间多箱型任务组合的集卡调度问题，本文根据运输过程中集卡剩余箱位随集卡执行任务动态变化的特点，考虑不同箱型任务需求与集卡当前状态的匹配，以集卡的启用、行驶及等待过程的成本最小化为目标，建立混合整数规划模型。并根据模型特点设计基于不可行弧过滤策略的蚁群算法，以提升算法性能。利用Solomon标准数据集 随机生成任务类型比例和规模大小不同的算例进行数值试验，试验结果证明了模型的正确性与算法的稳定性和有效性，进而对比了甩箱模式与传统模式下的总成本。结果表明：相较于传统模式，甩箱模式下集卡的运输总成本平均减少了45.10%；当任务规模越大时，两种模式之间的成本差距越大，显示了甩箱模式与港口多箱型集疏运任务运输作业结合的显著优势。     

A two-stage optimization approach for sulphur emission regulation compliance

In this paper, we present a two-stage optimization model for the machinery system selection problem. The objective is to minimize total cost, while aggregated power requirement and emission regulations are constraining the problem. Future fuel prices are considered to be uncertain. From a set of alternatives, the machinery configuration providing the lowest total cost is found. Also design flexibility in terms of future reconfiguration possibilities is taken into account. The machinery selection for a 2000 TEU container vessel is used as an illustrative case. Five initial machinery concepts are considered: diesel machinery, diesel machinery with a scrubber system, dual fuel (DF) machinery, pure gas engines, and a DF ready machinery. There is also a set of reconfiguration possibilities available for each alternative. From solving the case study, DF machinery is found optimal, while pure gas machinery is close to equally good. By solving the problem with deterministic fuel prices, the value of flexibility is not properly accounted for, resulting in an unreasonably high total cost for the flexible machinery alternatives. This demonstrates the need for a decision support approach that explicitly handles future uncertainty, as the two-stage stochastic model presented in this paper does.     

京沪高速铁路CRTS Ⅱ型轨道板预制生产线设计研究

结合固镇轨道板场建厂经验,从预制车间厂房设计、张拉台座设计、机械设备配置、供水、采暖、电器、供气等方面对CRTS Ⅱ型轨道板2×42预制生产线的设计进行介绍。     

某客运专线隧道岩溶处理方案技术经济比较

隧道岩溶处理方法多,投资额高,故必须合理确定和有效控制投资,使岩溶处理设计方案达到技术可行、经济合理的目标。以实际工程为背景,分别对同一隧道岩溶处理的桩基托梁、旋喷桩、微型桩三种方案进行了技术经济比较,推荐出一种技术可行、经济合理的处理方案。     

盐城到海安铁路扩能经济费用效益分析

新长铁路盐城北到海安县段为单线内燃牵引铁路,现状能力达到超饱和状态,亟需进行扩能改造。本次评价参照新版铁路建设项目经济评价标准,采用最新方法,对盐海铁路扩能进行经济效益和费用分析,从国民经济的角度对项目盈利水平做出评价,合理配置和有效利用资源。     

新的起点 新的高度——减速顶研究所五年来的技术创新与经济发展

哈尔滨铁路局减速顶调速系统研究中心2005年改名为减速顶调速系统研究所,同时领导班子几乎全部易人,机构进行了大调整,该单位开始了新起点;经过五年的努力奋斗,技术创新、市场开发和经济效益取得了长足进步,人均年产值和人均年收入创下了新纪录,单位的各项工作达到了新的高度。     

Analysis of Class 8 truck technologies for their fuel savings and economics

Non-electrification efficiency-improving technologies and powertrain technologies for reducing the heavy-duty truck fuel consumption are studied. The study indicates that improvements in engine efficiency, aerodynamic drag and rolling resistance will benefit fuel economy significantly over the day drive and over-the-road highway driving cycles; 6–13% in fuel savings can be expected from each technology. Hybridization can achieve fuel saving of 16% and is financially attractive for the day drive cycle. Compared to the baseline Class 8 conventional trucks, an improvement of 20–22% and 28–50% in fuel economy by 2020 can be expected using non-electrification efficiency-improving and a combination of non-electrification and hybrid technologies. Fuel economy improvements of a factor of four to five can be achieved by hybridizing the heavy-duty trucks used on ocean ports.     

IdleStop and Go: a way to improve fuel economy

This paper proposes a mechanical solution to save fuel by shutting down an internal combustion engine whenever it is unnecessary for propulsion, e.g., when a vehicle is waiting for traffic lights. The engine and vehicle are restarted using the energy that is stored in a flywheel. Two additional clutches are needed to enable appropriate power flow from the flywheel to the engine and vehicle. This complicates the powertrain dynamics in that the number of degrees of freedom changes due to clutch operations. Therefore, a hybrid control strategy, which is treated as a top-level controller, is introduced to deal with this finite-state mechanical system. At the lower level, the engine and clutches are controlled in a coordinated manner such that the vehicle is launched according to the driver's demands. Using a comprehensive powertrain simulation package, the proposed controller is evaluated numerically.     

纳米科技发展的思考

纳米科技是20世纪后期逐步发展起来的新兴科技.文章介绍了纳米科技在发达国家的发展和应用状况,且在分析我国纳米科技的发展状况的基础上,结合我国的国情,提出了加快我国纳米科技发展的建议和策略.     

交通行为建模－问题与机会

研究交通行为是科学规划与管理交通系统的基础.数学模型是整体把握交通行为的重 要工具.目前的交通行为模型注重适用性.而欠缺理论上的严密性,回顾了交通模型中的几个 经典成就,指出交通科学中还有许多问题等待解决,介绍了国际上传播交通模型的主要媒体.