天津港道路交通专项规划方案探讨

以《天津港道路交通专项规划》主要内容为依据,针对进港和港内道路交通系统衔接进行深入分析,提出适合港内道路交通需求分析的新方法,并给出若干规划方案,最终确定推荐方案。     

Effect of open skies in the Middle East region

This research aims to estimate potential inter-regional passenger flows for air transport in the Middle East under open skies polices, once deregulation agreements are reached between neighboring countries. To arrive at reasonable demand estimates, Western and Eastern European demand data was analyzed as a first step, since it is assumed that current Middle Eastern demand is distorted as a direct result of regional political instability. The major factors affecting demand, based on the European dataset, included population size, gross domestic product (GDP) per capita, absolute difference in GDP per capita between two countries, great circle distance and membership of the European Union and World Trade Organization. Subsequently, a 21 country database was estimated for passenger flow in the Middle East region on an average peak season day. The demand estimations became input for a hub location model (p-hub median formulation) in order to achieve the second major aim of this research, objective identification of potential regional gateways. The results proved robust to both single and multiple allocation model assumptions, with Cairo and Tehran consistently achieving hub status, along with Istanbul and Riyadh, as the number of potential hubs increased. Finally, this research shows that under conditions of peace, given existing socio-economic indicators, inter-regional passenger demand flow could increase by upwards of 51% and regulatory authorities ought to consider the necessary infrastructure and demand management policies to enable the conservative regional demand growth estimated.     

内贸海轮进出长江驾引力量需求预测研究

针对目前长江内贸船舶压港、滞港现象,运用灰色系统预测GM(1,1)模型对长江内贸船舶进出港艘次进行预测,进而求得未来几年内贸驾引力量需求数量。结果表明,未来几年长江内贸驾引力量需求数量巨大,驾引力量短缺严重。     

公众参与的交通需求管理

为了加强交通需求管理（TDM）整个过程中公众参与的程度,保障TDM的可实施性和有效性,提出了公众参与的交通需求管理概念。从公众的视角,分析了TDM与公众参与的关系和公众参与TDM的意义,总结提炼了公众参与TDM的原则、方法和策略,并初步探讨了公众参与交通需求管理的主要流程和实施框架,为合理制定交通需求管理政策提供了一种参考思路与方法。     

交通事故预警系统构建

针对交通安全现状及国内外交通预警发展现状的分析,阐明建立交通事故预警系统的必要性。分析了基于人、车、路、环境四要素的道路交通事故的成因,根据交通事故预警系统设计原则和建立预警系统的目的,采用相关理论,选用合适的交通信息采集技术,建立了交通事故预警系统。该系统包括驾驶员预警子系统、车辆防撞预警子系统、车辆状况预警子系统、道路安全预警子系统和交通气象预警子系统。     

回归分析方法在VTS预测研究中的应用

该文将数理统计中的回归分析方法应用到ＶＴＳ预测研究中，其预测结果有较高的精度，是基础理论应用于工程实际的有益实践，为ＶＴＳ规划研究提供了一种实用的预测方法。     

基于需求响应的铁路集装箱班列始发时刻优化

依据铁路运输生产实际,充分考虑集装箱货物与集装箱班列在时间和数量方面的匹配关系,以集装箱货物在集装箱办理站的总停留时间最小为优化目标,以集装箱货物装车唯一性、班列编成箱数、作业时间和发车间隔为约束条件,构建铁路集装箱班列始发时刻优化的非线性混合整数规划模型。根据模型的特点,设计基于遗传算法的求解方法。由随机产生和先到先服务方案结合的方法生成初始种群,并运用启发式策略修复进化过程中出现的不可行解。以胶州-黄岛之间的铁路集装箱班列为例进行仿真计算。结果表明:模型和算法具有较高的计算效率;利用模型及算法得到的集装箱班列始发时刻与集装箱货物的数量、到达时间分布之间具有较好的匹配性,使集装箱在办理站停留时间最短,制定的班列开行计划响应了用户需求。     

Identification and interpretation of spatial–temporal mismatch between taxi demand and supply using global positioning system data

Taxis provide a type of on-demand mobility service in urban transportation. There are growing concerns regarding the level of service of taxis in satisfying residents’ mobility demand. However, the mismatch between demand and supply of taxi services has not been resolved even with the introduction of app-based vehicle services. In this study, three indicators are constructed using the Shanghai taxi global positioning system (GPS) dataset to reveal the spatial–temporal mismatch pattern. The issue is further analyzed via a case study, in which seven regions with frequent mismatch patterns are identified in the time period from 21:00 to 22:00. Then, a multinomial logistic regression model is employed to identify the demographic and built-environment factors contributing to the taxi mismatch problem. The study results show that population density, residential areas, the number of points of interest, and road density have significant relationships with the taxi undersupply. In contrast, the areas of commercial lands, as well as the other two transportation-related factors, that is, the number of bus stops and the distance to nearest subway station, are observed to be statistically significant for both “oversupply” and “undersupply” conditions. This study provides valuable insights for identifying mismatch patterns and interpreting the mismatch problem as a function of spatially explicit factors that are of great use for urban governance, especially in the improvement of taxi efficiency, taxi management, and urban planning.     

Forecast verification of a 3D model of the Mediterranean Sea. The use of discrete wavelet transforms and EOFs in the skill assessment of spatial forecasts

The quality assessment of a nested model system of the Mediterranean Sea is realised. The model has two zooms in the Provençal Basin and in the Ligurian Sea, realised with a two-way nesting approach. The experiment lasts for nine weeks, and at each week sea surface temperature (SST) and sea level anomaly are assimilated. The quality assessment of the surface temperature is done in a spatio-temporal approach, to take into account the high complexity of the SST distribution. We focus on the multi-scale nature of oceanic processes using two powerful tools for spatio-temporal analysis, wavelets and Empirical Orthogonal Functions (EOFs). We apply two-dimensional wavelets to decompose the high-resolution model and observed SST into different spatial scales. The Ligurian Sea model results are compared to observations at each of those spatial scales, with special attention on how the assimilation affects the model behaviour. We also use EOFs to assess the similarities between the Mediterranean Sea model and the observed SST. The results show that the assimilation mainly affects the model large-scale features, whereas the small scales show little or no improvement and sometimes, even a decrease in their skill. The multiresolution analysis reveals the connection between large- and small-scale errors, and how the choice of the maximum correlation length of the assimilation scheme affects the distribution of the model error among the different spatial scales.     

震后交通需求预测的修正四阶段法

将城市震后交通系统运行划分为两个阶段:震后应急阶段及震后恢复阶段,并根据地震环境下不同恢复阶段的社会经济活动及交通系统特性对传统交通预测四阶段法———出行产生、出行分布、方式划分、交通分配的宏观模型进行修正,讨论不同模型参数的变化趋势,建议参数的调整原则及方法,进而以修正四阶段法为基础进行震后交通需求预测。该方法简便易行,预测结果可对城市交通系统防灾规划提供决策依据。