福州火车站站前地下广场建筑设计

本文通过福州火车站站前地下广场工程建筑设计实践,论述了在地下空间建设复杂的交通枢纽及综合商业建筑工程的可能性和现实意义。     

Combined empty and loaded train scheduling for dedicated freight railway corridors

The efficient utilization of expensive rolling-stock has become imperative for all railroads. In this paper, we study the combined empty and loaded train-scheduling problem for the upcoming dedicated freight corridors in India. Existing optimization models either do not consider the simultaneous optimization of the loaded and empty flows or are not solvable for large railroads. Our model is the first of its kind to incorporate link capacity constraints in an IP formulation for this operational level problem. A simulated annealing algorithm hybridized with a constructive heuristic is proposed as the solution method. The computational experiments show that the proposed heuristic performs well both in terms of runtime and solution quality.     

Physical,mental, emotional,and subjective workload components in train drivers

This study, using 12 train drivers on a high speed track and 11 drivers on a mountain track, tried to differentiate between the physical, emotional, mental, and subjective workload components imposed on the drivers during work. With the simultaneous recording and on-line analysis of heart rate and physical activity, the emotional component in terms of the so-called additional heart rate was separated from the physical component. Mental workload was calculated by the heart rate variability and by shifts in the T-wave amplitude of the ECG. Speed of the train, mode of driving, and stress of the situation were rated by two observers who accompanied the drivers in the cabin. During speeds up to l00km/h as compared to standstills no heart rate changes occurred, but with speeds from l00km/h up to 200 km/h heart rate decreased indicating a monotony effect. However, heart rate variability, and T-wave amplitude indicated higher mental load during driving in most speed categories. Starting the train and coming to a halt showed greater emotional workload as compared to moving. Observer ratings of stress and subjective ratings of stress by the drivers revealed several discrepancies. Discrepancies were also seen between workload as indicated by the physiological parameters, and corresponding stress ratings by the observers or by the drivers.     

Investigations into the skills of modern and traditional train driving

Rail operations are housed inside a complex and extremely dynamic system where work is distributed in time and space. The train driver has traditionally relied on their own decisions, plans, and actions to navigate the rail environment, but the use of modern driver systems that force how these activities are regulated has altered this dynamic. This paper reports the findings of a study that set out to investigate the skills of modern (enhanced display-based) and traditional (real world) train driving. Data were collected from a variety of UK domain experts (n = 45) using an innovative methodology that converged multiple techniques for knowledge elicitation and analysis. The findings are represented in a model of dynamic train control and discussed according to the specific features and nature of tracking skill in the rail domain. The utility of the model is demonstrated through work of its application to the design of a train simulator and research tool for systematic study of rail human factor issues.     

高铁规划要点及测试情况分析

从理论分析、实地测试2个方面同时入手,针对郑西高铁测试过程中发现的问题提出了解决思路和实施方案,并给出了高铁规划中的一些技术要点.     

车轴加工基准定位对轴表面残余应力的影响分析

加工基准对车轴表面加工质量有一定影响,为了定量分析由于偏心切削造成的影响程度,从理论上对加工基准误差与加工后车轴表面残余应力的相对关系进行了分析,针对偏心切削对表面残余应力的影响规律进行了研究。设计了在不同偏心量下的切削加工试验,对切削后试件轴表面残余应力进行了测量,试验结果表明,偏心切削对表面残余应力存在一定影响,但是影响程度不是很大。     

列车风挡曲线通过能力试验台研发

随着中国高速列车的快速发展,风挡作为列车车厢与车厢之间的重要连接部分,其产品质量的好坏直接决定着列车运行的安全性及旅客乘坐的舒适性。为检测风挡在列车运行到不同路况极限位置时产品的质量状况,设计了一种由三坐标移动平台和三坐标旋转平台组成的曲线通过能力试验台。该试验台可模拟列车在轨道运行时的直线拉伸压缩、曲线入口、曲线弧顶、反曲线、爬坡等多种极限位置路况。该控制系统以工控机作为上位机,PLC作为下位机,伺服电机为执行机构,采用模块化思想实现试验的自动化控制。     

初探破局电动汽车发展瓶颈新思路

制约电动汽车普及的因素很多,其中动力电池及其续驶里程已经成为关键的瓶颈。本文提出了车电分离、统一电池标准、换电"云能源"管理、智能电网与电动汽车互动等一系列思路,探索电动汽车普及的新途径。     

Exact formulations and algorithm for the train timetabling problem with dynamic demand

In this paper we study the design and optimization of train timetabling adapted to a dynamic demand environment. This problem arises in rapid train services which are common in most important cities. We present three formulations for the problem, with the aim of minimizing passenger average waiting time. The most intuitive model would consider binary variables representing train departure times but it yields to non-linear objective function. Instead, we introduce flow variables, which allow a linear representation of the objective function. We provide incremental improvements on these formulations, which allows us to evaluate and compare the benefits and disadvantages of each modification. We present a branch-and-cut algorithm applicable to all formulations. Through extensive computational experiments on several instances derived from real data provided by the Madrid Metropolitan Railway, we show the advantages of designing a timetable adapted to the demand pattern, as opposed to a regular timetable. We also perform an extensive computational comparison of all linear formulations in terms of size, solution quality and running time.     

Scheduling trains as a blocking parallel-machine job shop scheduling problem

In this paper, the train scheduling problem is modelled as a blocking parallel-machine job shop scheduling (BPMJSS) problem. In the model, trains, single-track sections and multiple-track sections, respectively, are synonymous with jobs, single machines and parallel machines, and an operation is regarded as the movement/traversal of a train across a section. Due to the lack of buffer space, the real-life case should consider blocking or hold-while-wait constraints, which means that a track section cannot release and must hold the train until next section on the routing becomes available. Based on literature review and our analysis, it is very hard to find a feasible complete schedule directly for BPMJSS problems. Firstly, a parallel-machine job-shop-scheduling (PMJSS) problem is solved by an improved shifting bottleneck procedure (SBP) algorithm without considering blocking conditions. Inspired by the proposed SBP algorithm, feasibility satisfaction procedure (FSP) algorithm is developed to solve and analyse the BPMJSS problem, by an alternative graph model that is an extension of the classical disjunctive graph models. The proposed algorithms have been implemented and validated using real-world data from Queensland Rail. Sensitivity analysis has been applied by considering train length, upgrading track sections, increasing train speed and changing bottleneck sections. The outcomes show that the proposed methodology would be a very useful tool for the real-life train scheduling problems.