Optimal development of alternative fuel station networks considering node capacity restrictions

A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is the use of alternative fuel vehicles (AFV). As global GHG emission standards have been in place for passenger cars for several years, infrastructure modelling for new AFV is an established topic. However, as the regulatory focus shifts towards heavy-duty vehicles (HDV), the market diffusion of AFV-HDV will increase as will planning the relevant AFV infrastructure for HDV. Existing modelling approaches need to be adapted, because the energy demand per individual refill increases significantly for HDV and there are regulatory as well as technical limitations for alternative fuel station (AFS) capacities at the same time. While the current research takes capacity restrictions for single stations into account, capacity limits for locations (i.e. nodes) – the places where refuelling stations are built such as highway entries, exits or intersections – are not yet considered. We extend existing models in this respect and introduce an optimal development for AFS considering (station) location capacity restrictions. The proposed method is applied to a case study of a potential fuel cell heavy-duty vehicle AFS network. We find that the location capacity limit has a major impact on the number of stations required, station utilization and station portfolio variety.     

基于执业能力视角的卓越造价工程师的培养

国家提出“实施卓越工程师人才教育培养计划”,为工程造价专业的发展创造了新的机遇。但在实施“卓越工程师”计划中如何开创新的教育模式,此文在基于工程建设的需求和培养卓越造价工程师的愿景,从强化执业能力训练的角度,对如何培养卓越造价工程师提出实施策略和几点设想。     

美国铁路煤炭运输

介绍美国铁路煤炭运输的发展概况与产销特点：煤炭资源丰富,产地集中,消费的地域集中度不高,但其产业集中度很高。煤炭运输的产销特点决定了美国铁路煤炭的运输组织方式以单元列车为主,技术装备配置以煤炭客户自备车为主。其煤炭运价分为公布运价和合同运价,当燃油价格超过基准价格时,美国铁路运输公司收取燃油附加费。由于煤炭运输市场竞争充分,煤炭供求双方具备强大的市场谈判能力,因此美国铁路煤炭运输的收入率较低。     

A new shared control for lane keeping and road departure prevention

In recent years, the driver's active assistances have become important features in commercialised vehicles. In this paper, we present one of these features which consists of an advanced driver assistance system for lane keeping. A thorough analysis of its performance and stability with respect to variations in driver behaviour will be given. Firstly, the lateral control model based on visual preview is established and the kinematics model based on visual preview, including speed and other factors, is used to calculate the lateral error and direction error. Secondly, and according to the characteristics of the lateral control, an efficient strategy of intelligent electric vehicle lateral mode is proposed. The integration of the vehicle current lateral error and direction error is chosen as the parameter of the sliding mode switching function to design the sliding surface. The control variables are adjusted according to the fuzzy control rules to ensure that they meet the existence and reaching condition. A new fuzzy logic-based switching strategy with an efficient control law is also proposed to ensure a level of continuous and variable sharing according to the state of the driver and the vehicle positioning on the roadway. The proposed control law acts either at the centre of the lane, as a lane keeping assistance system to reduce the driver's workload for long trips, or as a lane departure avoidance system that intervenes for unintended lane departures. Simulation results are included in this paper to explain this concept.     

探析突破施工企业成本核算人才瓶颈的对策

文章从某施工企业项目成本核算人才缺失的现状出发,分析了施工企业成本核算人才缺失的原因及危害,提出了突破施工企业成本核算人才瓶颈的对策。     

基于船舶安全航行研究

船舶在航行过程中应遵循安全、经济的原则,其中安全尤为重要。文中就如何保证船舶安全航行作了一些深入的调查与研究,得出了保持正规了望、正确使用航海雷达、严格落实值班制度和尽量避免紧迫局面等几个切实可行的方法,以期引起航海者的高度重视,极其谨慎地驾驶船舶,以避免出现碰撞事故。     

浅析工程项目成本可视化管理

工程项目在企业经营中发挥着越来越重要的主导作用,然而却存在着项目成本管理粗放、成本控制不到位等问题。针对目前公路市场现状,以项目成本管理得失为例,提出项目成本可视化管理模式。     

浅谈施工企业中项目的成本管理

施工企业中项目成本管理至关重要,详细介绍了成本预测及成本管理的内容。     

基于驾驶模拟器的雾天驾驶行为特性研究

在不同指令和速度反馈机制下进行了分组试验,模拟分析500,200,80,50和30 m能见度下驾驶速度选择和车道保持特性。结果表明：随着能见度的降低,车辆速度呈先升高后降低的趋势,实际速度与期望速度不匹配;除30 m能见度外,能见度降低未对驾驶员车道保持能力产生影响;80 m能见度下平均车速和车道保持率最高。     

Towards a simplified performance-linked value for money model as a reference point for bus contract payments

The burgeoning commitment to contracting the delivery of bus services through competitive tendering or negotiated performance-based contracts has been accompanied by as many contract payments schemes as there are contracts. We are now well placed to design a simplified performance-linked payment (SPLP) model that can be used as a reference point to ensure value for money, given the accumulation of experiences throughout the world which have revealed substantive common elements in contracts. Whether the payment to the operator is framed as a payment per passenger or as a payment per service kilometre, the SPLP identifies efficient subsidy outcomes that are linked to a proxy indicator of net social benefit per dollar of subsidy. We illustrate how the SPLP model can be applied to obtain the gross (subsidy) cost per passenger (or per passenger km) from measures of gross cost efficiency and network effectiveness. This model can then be used as part of a benchmarking activity to identify reference value of money prospects in respect of passengers per $ subsidy outlay by adjusting for influences not under the control of the service provider. A single framework to identify contract payments to operators, and to assess (i.e., benchmark) operator performance on critical KPIs, is provided by internalising critical key performance indicators (KPIs) in the design of the SPLP. The proposed SPLP model is sufficiently general to be independent of the procurement method (competitive tendered or negotiated, for example) and of the treatment of revenue allocation (net or gross based contracts), with the additional advantage of being able to assess value for money for government.