城市道路工程管线预留沟设置探讨

城市道路下有众多的市政管线服务于周边地块,市政管线通常需横穿道路敷设以满足道路两侧用户的供给需求。为了减少新建过路管线时对已建道路影响,城市道路建设时可以同步实施管线过路预留设施,其中工程管线预留沟为一种有效方式。通过分析和总结南方某城市工程管线预留沟多年的设置经验,从设置条件及布置间距等方面提出了的建议。     

上海地铁车辆外挂门用户可调参数的设置

鉴于外挂式车门在实际运用中出现的一些问题,对其可调参数的设置进行了分析。对关门时障碍物探测时间、开门时障碍物探测时间、障碍物探测后门打开的宽度、关门的延迟时间、障碍物探测次数、开门时间、关门时间,车门的停顿时间等参数根据实际客流情况进行微调以求达到最佳的动作状态。     

并联发电机组的有功分配差度分析与验证

论述了单台发电机组额定频率整定点和稳态频率调整率对两台发电机组并车后的有功功率分配差度的影响,给出了它们之间的关联算式,实际对两台电动发电机组进行了并车试验,验证了理论分析的正确性.     

自由设站放样测量在轨道交通连续刚构PC梁架设中的应用

芜湖轨道交通二号线是国内外首次采用跨坐式连续刚构PC梁的轨道交通项目,相较于国内外现有轨道交通项目的跨坐式简支PC梁,在梁体安装精度、线路平顺性控制、施工技术难度等方面均优于跨坐式简支PC梁。介绍了跨坐式连续刚构PC梁架设中自由设站放样测量控制网的测设原理、布点方法及布点形式,利用自由设站放样测量方法设站灵活、放样精度高等特点,结合自主研发的专用放样工装设备,解决了轻轨跨坐式连续刚构PC梁架设中测量精度不稳定、高程上桥困难、作业时遮挡严重、测量人员安全风险大、多榀梁连接平顺性差等测量难题,可将轨道梁中线偏差控制在3 mm以内,轨道梁中心变化率控制在1.5 mm/1.5 m以内,线路超高情况下的角度公差控制在±1/8°以内。实践证明:自由设站放样测量能够满足轨道PC梁精调施工定位的精度要求,且效率高、精度高、安全性高,在同类项目中具有推广和应用价值。     

Methods for pre-processing smartcard data to improve data quality

In recent years smartcards have been implemented in many transit systems around the world as a means by which passengers pay for travel. In addition to allowing speedier boardings there are many secondary benefits of smartcard systems including better understanding of travel patterns and behaviour of travellers. Such research is dependent on the smartcard correctly recording the boarding stop, and where available the alighting stop. It is also dependent on the smartcard system correctly aggregating individual rides into trips.This paper identifies causes for why smartcard systems may not correctly record such information. The first contribution of the paper is to propose a set of rules to aggregate individual rides into a single trip. This is critical in the research of activity based modelling as well as for correctly charging the passenger. The second contribution of the paper is to provide an approach to identify erroneous tap-out data, either caused by system problems or by the user. An approach to detecting this phenomenon is provided. The output from this analysis is then used to identify faulty vehicles or data supply using the “comparison against peers approach”. This third contribution of the paper identifies where transit agencies and operators should target resources to improve performance of their Automatic Vehicle Location systems. This method could also be used to identify users who appear to be tapping out too early.The approaches are tested using smartcard data from the Singapore public transport network from one week in April 2011. The results suggest that approximately 7.7% of all smartcard rides recorded the passenger as alighting one stop before the bus stop that they most probably alighted at. A further 0.7% of smartcard rides recorded the passenger as alighting more than one stop before the bus stop that they most probably alighted at. There was no evidence that smartcards overestimated the distance travelled by the passenger.     

A Granular Variable Tabu Neighborhood Search for the capacitated location-routing problem

This paper proposes a new heuristic algorithm for the Capacitated Location-Routing Problem (CLRP), called Granular Variable Tabu Neighborhood Search (GVTNS). This heuristic includes a Granular Tabu Search within a Variable Neighborhood Search algorithm. The proposed algorithm is experimentally compared on the benchmark instances from the literature with several of the most effective heuristics proposed for the solution of the CLRP, by taking into account the CPU time and the quality of the solutions obtained. The computational results show that GVTNS is able to obtain good average solutions in short CPU times, and to improve five best known solutions from the literature. The main contribution of this paper is to show a successful new heuristic for the CLRP, combining two known heuristic approaches to improve the global performance of the proposed algorithm for what concerns both the quality of the solutions and the computing times required to find them.     

Collective public-transport tickets and anticipated majority choice: A model of student tickets

In Germany, many universities have student tickets that are bargained for between student representatives and public transport companies, approved by referendum, and mandatory for all students. They allow the use of public transport at no additional cost. I analyze such a scenario in a theoretical model as an example of a flat-rate ticket for public transport which is implemented by majority decision. The mandatory character of the ticket reduces transaction costs like marketing and ticket inspection, reducing the ticket price and thus the students’ commuting expenses. However, there is a countervailing effect. Students face and rationally expect zero marginal monetary commuting costs, so that new students choose a place of residence which is relatively far from the university. This in turn raises the equilibrium ticket price. It may even be the case that students would be better off if such a ticket had never existed. Nonetheless, they always vote for it in referenda, because accepting the high price is optimal given their place of residence. After laying out the model, I analyze an optimal policy, which consists, for example, of subsidizing student dorms at an efficient distance to the city center.     

浅谈公共交通公众出行信息服务系统的应用

本文阐述了公众出行信息服务系统在公共交通领域中的应用,目标是建设个性化的公交实时位置信息接入平台,用户可以通过自己的手机,随时随地查询本市各公交车辆的实时位置、上下行方向等信息,方便市民适时安排自己的乘车计划,达到方便出行的目的.     

秦沈客运专线高速试验段线路缓和曲线动力学仿真分析

利用北美铁道协会 (AAR)开发的大型商业通用轮轨动力学仿真计算软件NUCARS ,对秦沈客运专线高速试验段采用的三次抛物线型缓和曲线进行了列车线路动力学仿真分析 ,并与日本新干线采用的半波正弦缓和曲线进行了对比 ;同时也对中国与日本新干线不同超高设置方法对轮轨动力学性能的影响进行了对比仿真计算。研究结果表明 ,现在使用的缓和曲线线型以及中国式超高设置方法满足秦沈线试验段高速试验要求的安全性和舒适性。