旅客列车发车时间域优化研究

在大量问卷调查的基础上,根据旅客对不同到发时间域选择的偏好,确定了各发车时间域旅客出行的方便系数。利用目标规划原理,以旅客出行方便程度最大为目标,构造了三级控制策略。在考虑客运站到发线能力,以及旅客列车必须在合理的时间域发车等约束条件下,建立旅客列车发车时间域的目标规划模型。利用该目标规划模型,可根据旅客列车实际运行的需要,通过变化控制策略和赋予各目标的优先因子,实现对列车发车时间域的优化。根据模型约束目标正负偏差变量,计算了各级控制策略实现程度系数。最后,以太原站始发旅客列车为实例,利用变换方案对该目标规划模型的运用进行了分析,并将目标规划优化结果和传统确定发车时间域的结果以及指派模型优化结果进行比较分析。     

世界航运人才需求与中国外派海员预测

根据世界航运人才的需求状况,利用航运经济增长模型,测算出2010年世界航海人才的需求量,并运用多种方案预测出2010年中国外派航海人员的数量,以此为中国有关高校的航运人才的培养和相关国际人才中介服务公司的发展提供依据。     

绿色港湾建设

结合国内外10大著名港口实例,从规划设计、结构选型、使用年限确定、旧有建筑物的改造和再利用、提高环保理念和健全法规等方面,论述了＂绿色港湾＂建设的必要性和可行性,以探研绿色港湾建设及其相关概念,并提出建议。可供规划设计人员参考。     

液化天然气(LNG)接卸港工程

介绍了LNG国际贸易、接收站建设、LNG运输船、接卸港口工程的选址及设计、分销输运方式，讨论了关于《液化天然气码头设计规程》（试行）的修订意见。     

Estimation of value of travel time reliability

In mode choice decision, travelers consider not only travel time but also reliability of its modes. In this paper, reliability was expressed in terms of standard deviation and maximum delay that were measured based on triangular distribution. In order to estimate value of time and value of reliability, the Multinomial and Nested Logit models were used. The analysis results revealed that reliability is an important factor affecting mode choice decisions. Elasticity is used to estimate the impacts of the different policies and system improvements for water transportation mode. Among these policies, decision maker can assess and select the best alternative by doing the benefit and cost analysis based on a new market share, the value of time, and the value of reliability. Finally, a set of promising policies and system improvement of the water transportation were proposed.     

Ramp meters on trial: Evidence from the Twin Cities metering holiday

Ramp meters in the Twin Cities have been the subject of a recent test of their effectiveness, involving turning them off for eight weeks. This paper analyzes the results with and without ramp metering for several representative freeways during the afternoon peak period. Seven performance measures: mobility, equity, productivity, consumers’ surplus, accessibility, travel time variation and travel demand responses are compared. It is found that ramp meters are particularly helpful for long trips relative to short trips. Ramp metering, while generally beneficial to freeway segments, may not improve trip travel times (including ramp delays). The reduction in travel time variation comprises another benefit from ramp meters. Non-work trips and work trips respond differently to ramp meters. The results are mixed, suggesting a more refined ramp control algorithm, which explicitly considers ramp delay, is in order.     

浅谈农村公路建养管对策

全面推进农村经济的发展，首先要切实加强对农村公路发展工作的管理，促使公路建设管理水平再上新台阶。     

铁路货物运输的随机过程分析和及时送达概率估计

应用随机过程理论，分析铁路运输系统中货物及时送达的概率分布，得到货物运输延续时间的平均值，为实现用户要求的运到期限提供了合理保证，并可通过评估与货主商定的运到期限与实际货物送达时间误差的概率，来找到货物及时送达过程中的关键环节，改进货物送达流程。最后举例说明它的应用。     

基于改进粒子群优化算法的鲁棒性列车运行图编制方法

以列车优先级、追踪运行间隔时间和连发间隔时间限制为约束条件,以旅客列车的走行公里总数、平均旅行速度、对标准计划的延迟总时间和延迟时间方差,以及货物列车的日车公里总数和日产最6个指标无量纲转化后的合计值最大为综合目标函数,建立列车运行图编制优化模型.为增加列车运行图的鲁棒性,引入虚拟车和缓冲时间槽2个参数,采用改进的粒子群优化算法给出鲁棒性列车运行图编制方法.以5个车站、5列旅客列车和7列货物列车构造模拟环境,采用该方法进行列车运行图编制模拟.结果表明:该方法可铺画出更优的列车运行图,计算效率高;在行车计划受到扰动后,虚拟车和缓冲时间槽释放资源,运行图可以较快地恢复到可接受范围,容错鲁棒性好.     

25Hz轨道电路叠加电码化现场调整及开通

介绍了25Hz相敏轨道电路预叠加四线制电码化和四线制闭环叠加电码化后,针对送电端发码和受电端发码的不同,给出了轨道电路和电码化设备的测试调整方法和参数,并提出了现场开通的注意事项。