不确定客流条件下轨道交通全日行车计划的决策模拟

城市轨道交通系统的运输组织需要根据客流特点编制列车开行计划,其中全日行车计划是列车开行计划的基础,对列车开行方案、列车运行图和车辆运用计划具有重要影响。在简要介绍全日行车计划编制的主要内容和步骤基础上,利用Crystal Ball软件对客流计划不确定条件下的全日行车计划的编制进行模拟分析,模拟结果得到了包含更多辅助信息的决策方案,也为实际应用提供了可操作的新方法和工具。     

Adoption of an IMF programme and debt rescheduling. An empirical analysis

The existence of an empirical relationship between the adoption of an IMF programme and the concession of a debt rescheduling by commercial creditors is tested using a bivariate probit model. If countries who have arrangements with the IMF are more likely than others to obtain a rescheduling of their external debt, we could conclude that the adoption of an IMF programme could work as a sort of signal of a country's “good intent” which is thus rewarded with the debt relief. The results confirm the existence of a significant effect of the adoption of an IMF programme on the subsequent concession of a debt rescheduling by private creditors.     

高速铁路CTCS3+ATO系统优化方案研究

随着我国高速铁路网逐年扩大,对于自动驾驶的需求不断增加,为满足高速铁路高速度、高密度跨线运营需求,实现装备智能化,阐述高速铁路CTCS3+ATO系统结构及设备功能,分析高速铁路CTCS3+ATO系统需求,考虑到城际铁路CTCS2+ATO系统及高速铁路CTCS3+ATO系统实际运用情况,结合CTCS3+ATO系统技术特点,提出升级列车定位技术、改变区间闭塞制式、立即折返作业自动化、实现全自动无人驾驶等高速铁路CTCS3+ATO系统优化方案。该方案的实施及应用有助于在保障列车运行安全的前提下,提高自动化运行程度及运输效率。     

适应高速铁路自动驾驶系统的列车运行计划调整策略研究

高速铁路列车自动驾驶(ATO)系统是铁路智能化发展的重要组成部分,其应用实现了列车运行多项功能的联动控制,显著提升了高速铁路自动化水平,减轻了工作人员的劳动强度。我国铁路网密度大、运用场景复杂,列车运行计划实时调整难度较大,对ATO系统运用有更高的要求。基于ATO系统工作原理,分析ATO系统与运行计划的关联关系,总结列车运行计划与ATO系统适应性存在的不足,提出了适应ATO系统的列车运行计划调整策略,可以为优化ATO列车运行计划调整策略、提升高速铁路服务水平与效能提供支撑。     

A matheuristic approach to the air-cargo recovery problem under demand disruption

Air cargo transport is subject to unpredictable changes in expected demand, necessitating adjustments to itinerary planning to recover from such disruptions. We study a flight rescheduling problem to react to cargo demand disruptions in the short run. To increase flexibility, we consider two different cargo assignment policies. We propose a matheuristic approach to solve the problem that provides high-quality solutions in a short computational time, based on column generation in which each subproblem is solved using an ad-hoc heuristic. The approach is tested on demand disruption instances containing up to 75 air cargo orders with different penalty levels. The results show that the proposed method improves profit by 54% over the solution generated by a commercial MIP solver within a 1-h time limit, and by 15% over the solution with the routes fixed as in the original flight planning that only allows cargo to be re-routed. We also show that there exist incremental benefits in the range of 3–5% by allowing cargo for a given order to be transported by various aircraft.     

市域铁路列车运行组织探讨

近年来,我国现有的城市轨道交通系统逐渐难以满足城区与市郊之间的出行需求,市域铁路成为城市群轨道交通发展的新方向,但我国尚缺乏成熟的市域铁路不同等级列车运行组织模式。在分析国内外市域铁路运行组织及不同等级列车开行现状基础上,提出市域铁路开行不同等级列车的运输组织优化方案,优化市域铁路列车等级设置原则、开行方案、换乘模式,以北京城市副中心线(良乡—乔庄东)为例,提出副中心线运行组织优化建议,为实现都市圈城市轨道交通一体化,促进中心城市与周边城市协调发展提供支撑。     

地铁列车司机轮班疲劳风险分析

从地铁列车司机轮班制作业方式出发,分析引起司机驾驶疲劳的影响因素,选择确定疲劳指数并建立数学模型,对疲劳风险等级进行评定。选取北京地铁2号线列车司机为研究对象,评估其按现行工作时刻表轮乘后的疲劳程度。采用生理测量的方式,以闪光融合频率为评价指标,对疲劳指数的评估结果进行验证,说明该方法应用于我国轨道交通领域具有可行性。     

普通平车运输50m长道岔轨的动力学仿真研究

针对50 m长道岔轨采用普通平车运输方案的特点,建立了运输方案动力学计算模型。对运输车组侧向通过9号、12号道岔和通过半径为300 m曲线的各种速度工况进行了仿真计算,在理论上分析了方案的运行安全性。在仿真计算的基础上,对方案进行了实际道岔、小半径曲线和长距离运行试验。试验结果表明,50 m长道岔轨采用普通平车运输方案的运行安全性满足运输要求,并且该运输方案已在攀钢实际应用。     

Train access and financial performance of local authorities: greater Tel Aviv as a case study

In this paper, we examine the assumption that as a municipality obtains train access, its financial performance improves. Using the case study of the Greater Tel Aviv Metropolitan Area (GTAMA) we conclude that this link is neither obvious nor uniform. The main outcome of the study is that, upon gaining train access, centrally-located municipalities, such as Tel Aviv, significantly increase their revenue base. Concurrently, municipalities located in the peripheral areas of the metropolis improve their performance only marginally and even decline in their attractiveness to migrants, as a result of train access. As suggested, this difference may be explained by the socio-economic structure of each municipality group, which affects their ability to take advantage of the rail. These findings send a message to planners and decision-makers that establishment of train access does not necessarily improve the financial performance of local authorities, and can even limit their demographic growth. Other factors, such as urban functionality and location, should thus be taken into account in assessing the potential benefits and drawbacks associated with rail expansion.     

基于动态约束的炼钢连铸重调度算法设计

针对炼钢连铸过程中出现的新炉次插入的重调度问题,考虑实际生产中的工艺约束,以最小化开工时间差异度、加工机器差异度的加权和为目标函数建立动态调度模型,采用回溯算法与启发式规则结合的算法。用Matlab7.8.0软件对选取的算例进行仿真,结果表明,此算法能保证重调度结果的实时性和有效性。