Combinations of Transportation Policies to Promote BRT Usage Using Artificial Society Model

Various transportation systems have been developed in recent years.In this study,an artificial society model is developed to examine the combination of transportation policies in urban areas.In this model,each trip maker selects the primary and terminal transportation modes.An artificial society model is applied to the southeastern region of Osaka City,Japan.The effects of introducing BRT(bus rapid transit,primary transportation)and on-demand buses(terminal transportation)are investigated.The results confirm that BRT is used by a certain number of users.An increase in the use of BRT will increase the amount of walking,thus resulting in a healthy city.However,on-demand buses are rarely used as terminal transportation.Additionally,the development of bicycle parking stations near BRT stops is shown to be effective in the northern section of the BRT route.

Multi-Objective Multi-Dimensional Transportation: A Case Study to the Flow of the Commodities of the Main Roads to Main Nodes in the North Western Coastal Strip of Egypt

The distribution of merchandises and commodities from source towns to final destinations is a vital issue. The job of transporter’s decisions can be optimized by reformulating the transportation problem as generalization of the classical transportation problems. Multiobjective multi-dimensional transportation network is considered the extension of conventional two-dimensional transportation network and is convenient for dealing with transportation systems with multiple supply nodes, multiple demand nodes, as well as diverse modes of transportation demands or delivering multiple kinds of merchandises. In this study, we implement an improved Biogeography based optimization IBBO to the flow of the commodities of the main roads to main nodes in the North Western Coastal Strip of Egypt, where there are four main roads and three nodes. The proposed algorithm incorporates the dominance criteria to handle multiple objective functions which enable the decision maker to cover all the Pareto frontier of the problem which have a large-scale size. Numerical results were reported in order to establish the real computational burden of the proposed algorithm and to assess its convergence performances for solving real geographical problem.

Transportation Development Transition in China

Scientific development is an invaluable asset to a country.Policies and development modes should be carried out based on scientific findings not only in industry,but also in transportation infrastructure construction.Building an integrated transportation system,which is in line with the national requirements of China and supports sustainable socio-economic development,is a key strategic issue related to building a moderately prosperous society and achieving realistic goals of a medium-level developed country.Based on a systematic review of the advances in China's transportation infrastructure over the last 60 years,this paper explores the main drivers of transportation development,including national policy,transportation structure,investment efficiency,and technological innovation.Analysis shows that China's comprehensive transportation infrastructure construction since 1949 can be divided into five stages initiated by these drivers,which correspond to four transition modes:policy transition,structural transition,efficiency transition,and technology transition.The transition path of China's transportation development shows that the dominant factors have changed,and the interval for each transition has shortened.With the implementation of the '12th Five-Year Plan',China's transportation infrastructure construction is showing some new characteristics and facing a new development transition.Finally,this paper analyzes the trends in transportation development in China and concludes that technological innovation will be the main driving force to increase the transportation supply and service area in the future.

Users’ Perception on Operation and Performance of Public Transport Systems in African Developing Countries: The Case of Bus Rapid Transit (BRT) in Dar es Salaam City, Tanzania

Public transport system has been a means of addressing transportation challenges in urban areas, such as traffic congestion, traffic jam and long travel time in cities worldwide. Transportation in Africa is unique in that it has the least developed public transport systems in the world, while also being one of the fastest urbanizing continents. Bus Rapid Transit being one of the public transport systems was introduced in Africa in 2008 as a means to provide solution on urban transportation challenges. Despite of public transport being the main means of transport in African developing countries, there have been a number of challenges that affects efficiency of performance of the system and makes its users uncomfortable. Therefore, the study aimed at exploring the setbacks or challenges associated with operation and performance of the BRT system in the African developing countries and address them. The study employed mixed methods research design that integrates both qualitative and quantitative data collection methods and analysis. The study findings reveal that, there is an improvement on the perspectives of the commuters on public transport after introduction of BRT system. However, some challenges such as long waiting time, passengers overcrowding during peak hours, as well as safety and security can slowly change the perspective of the commuters. Therefore, to address these challenges it is recommended to reduce the long waiting time and improve accessibility by introduction of passenger information displays (bus information system) and automated fare collection system;reduce travel time by introduction of bus priority signal;and improve safety and security by introduction of signage and CCTV Camera within the bus and bus stops.

Seasonal Transition Features of Large-Scale Moisture Transport in the Asian-Australian Monsoon Region

Using NCEP/NCAR reanalysis data for the period of 1957-2001, the climatological seasonal transition features of large-scale vertically integrated moisture transport （VIMT） in the Asian-Australian monsoon region are investigated in this paper. The basic features of the seasonal transition of VIMT from winter to summer are the establishment of the summertime ＂great moisture river＂ pattern （named the GMR pattern） and its eastward expansion, associated with a series of climatological events which occurred in some ＂key periods＂, which include the occurrence of the notable southerly VIMT over the Indochina Peninsula in mid March, the activity of the low VIMT vortex around Sri Lanka in late April, and the onset of the South China Sea summer monsoon in mid May, among others. However, during the transition from summer to winter, the characteristics are mainly exhibited by the establishment of the easterly VIMT belt located in the tropical area, accompanied by some events occurring in ＂key periods＂. Further analyses disclose a great difference between the Indian and East Asian monsoon regions when viewed from the meridional migration of the westerly VIMT during the seasonal change process, according to which the Asian monsoon region can be easily divided into two parts along the western side of the Indochina Peninsula and it may also denote different formation mechanisms between the two regions.

Low-Temperature Growing Anatase TiO2/SnO2 Multi-dimensional Heterojunctions at MXene Conductive Network for High-Efficient Perovskite Solar Cells

A multi-dimensional conductive heterojunction structure,composited by TiO2,SnO2,and Ti3C2TX MXene,is facilely designed and applied as electron transport layer in efficient and stable planar perovskite solar cells.Based on an oxygen vacancy scramble effect,the zero-dimensional anatase TiO2 quantum dots,surrounding on two-dimensional conductive Ti3C2TX sheets,are in situ rooted on three-dimensional SnO2 nanoparticles,constructing nanoscale TiO2/SnO2 heterojunctions.The fabrication is implemented in a controlled lowtemperature anneal method in air and then in N2 atmospheres.With the optimal MXene content,the optical property,the crystallinity of perovskite layer,and internal interfaces are all facilitated,contributing more amount of carrier with effective and rapid transferring in device.The champion power conversion efficiency of resultant perovskite solar cells achieves 19.14%,yet that of counterpart is just 16.83%.In addition,it can also maintain almost 85%of its initial performance for more than 45 days in 30–40%humidity air;comparatively,the counterpart declines to just below 75%of its initial performance.

Formation of Edge Transport Barriers by L-H Transition and Large Reversed Plasma Current on LHD

On the Large Helical Device （LHD） where nested magnetic surfaces are surrounded by the ergodic field layer, edge transport barrier （ETB） was produced in neutral-beam-injection （NBI） heated plasmas through transition and non-transition processes. The former case is the ETB formation by L-Htransition, where characteristics of L-H transition observed in a tokamak plasma are clearly recognized. The confinement improvement is the modest （- 10%）, compared with the ISS95 international stellarator scaling. The threshold power for the transition is comparable or slightly lower than the ITER scaling law established by tokamaks and compact tori. The ETB is formed inside the ergodic field layer of the vacuum field. The ETB formation destabilizes edge coherent modes such as m/n = 1/1, 2/3 and 1/2, of which rational surfaces are in the magnetic hill. The formed ETB is partially and transiently destroyed by these coherent edge MHD modes and edge localized modes （ELMs） typically observed in Ha signals. The latter ETB is observed in a plasma with large reversed NBI-driven current more than 100 kA at Bt = 1 T. In these plasmas, the edge magnetic shear is enhanced by the current and the rotational transform in the core region is expected to be appreciably reduced. Thus reduced rotational transform in the plasma central region will enhance outward heat and particle fluxes toward ergodic edge layer. The ETB with steep electron temperature gradient up to - 5 keV/m is formed by blocking enhanced outward heat flux.

Phase transition and charge transport through a triple dot device beyond the Kondo regime

Semiconductor quantum dot structure provides a promising basis for quantum information processing, within which to reveal the quantum phase and charge transport is one of the most important issues. In this paper, by means of the numerical renormalization group technique, we study the quantum phase transition and the charge transport for a parallel triple dot device in the strongly correlated limit, focusing on the effect of inter-dot hopping t beyond the Kondo regime. We find the quantum behaviors depend closely on the initial electron number on the dots, and the present model may map to single,double, and side-coupled impurity models in different parameter spaces. An orbital spin-1/2 Kondo effect between the conduction leads and the bonding orbital, and several magnetic-frustration phases are demonstrated when t is adjusted to different regimes. To understand these phenomena, a canonical transformation of the energy levels is given, and important physical quantities with respect to increasing t and necessary theoretical discussions are shown.

A new formula of recovery factor for non-equilibrium transport of graded suspended sediment in the Middle Yangtze River

Suspended sediment concentrations in the Middle Yangtze River(MYR)reduced greatly after the Three Gorges Project operation,causing the composition of bed material to coarsen continuously.However,little is known about the non-equilibrium transport of graded suspended sediment owing to different bed material compositions(BMCs)along the MYR,and it is necessary to determine the magnitude of recovery factor.Using the Markov stochastic process in conjunction with the hiding-exposure effect of non-uniform bed-material,a new formula is proposed for calculating the recovery factor including the effect of different BMCs,and it is incorporated into the non-equilibrium transport equation to simulate the recovery processes of suspended load in both sand-gravel bed and sand bed reaches of the MYR.The results show that:(i)the recovery rate of graded sediment concentrations at Zhicheng was slower than that at Shashi during the period 2003-2007;(ii)the mean recovery factors of the coarse,medium,and fine sediment fractions in the ZhichengShashi reach were 0.152,0.0012,and 0.0005,respectively,and the coarse sediment recovered up to the maximum sediment concentration of 0.138 kg/m3over a distance of 15 km;and(iii)the results of the new formula that can consider the effect of bed material composition are in general agreement with the field observations,and the spatial and temporal delay effects are inversely related to particle size and BMC.Consequently,the BMC effect on the nonequilibrium sediment transport in different reaches of the MYR needs to be considered for higher simulation accuracy.

A Multi-Mode Public Transportation System Using Vehicular to Network Architecture

The number of accidents in the campus of Suranaree University of Technology(SUT)has increased due to increasing number of personal vehicles.In this paper,we focus on the development of public transportation system using Intelligent Transportation System(ITS)along with the limitation of personal vehicles using sharing economy model.The SUT Smart Transit is utilized as a major public transportation system,while MoreSai@SUT(electric motorcycle services)is a minor public transportation system in this work.They are called Multi-Mode Transportation system as a combination.Moreover,a Vehicle toNetwork(V2N)is used for developing theMulti-Mode Transportation system in the campus.Due to equipping vehicles with On Board Unit(OBU)and 4G LTE modules,the real time speed and locations are transmitted to the cloud.The data is then applied in the proposed mathematical model for the estimation of Estimated Time of Arrival(ETA).In terms of vehicle classifications and counts,we deployed CCTV cameras,and the recorded videos are analyzed by using You Only Look Once(YOLO)algorithm.The simulation and measurement results of SUT Smart Transit and MoreSai@SUT before the covid-19 pandemic are discussed.Contrary to the existing researches,the proposed system is implemented in the real environment.The final results unveil the attractiveness and satisfaction of users.Also,due to the proposed system,the CO_(2) gas gets reduced when Multi-Mode Transportation is implemented practically in the campus.

The Challenges Faced on Transit Transport Corridors by Landlocked Countries in Central Africa: Literature Review

The landlocked countries are the one without access to the sea and can be assimilate as countries around the world with a disadvantage of geography situation location. Chad and the Central African Republic are two of the 40 landlocked countries around the world that transport 80% of their goods by road and rail, and as much as almost more than 50% of their passengers through a transit country with a transit transport system which is crucial for their trade and exchanges. The study aims to introduce the importance to have a good and efficiency transport network infrastructure in Central Africa to facilitate the trade for the landlocked countries of Central Africa (Chad and the Central African Republic), member of CEMAC trade area and proposes some measures that can be adopted to improve their conditions and ameliorate the trade for those countries.

公交专用车道规划管理思辨及公共汽电车交通发展纾困

2023年上半年,公安部推出10项公安交管新措施,其中包括优化城市公交专用车道管理。北京、深圳、青岛、南通等地陆续发布公交专用车道相关管理措施,引发广泛讨论与关注。围绕公交专用车道管理措施背后的原因与调整的依据,公交专用车道本身的规划、管理与使用问题,以及公共汽电车交通运营困境,特邀城市交通行业专家学者和公共汽电车运营管理研究的一线工作人员以笔谈的形式交流观点。在此基础上,探索在城市存量发展阶段如何建立常态化路权变更规则和评估机制,以及公共汽电车交通纾困之路。

中国“新能源矿产目录”厘定研究

全球能源体系正在加速从传统能源向新能源转变,新能源产业发展需要的矿产资源已成为大国博弈的焦点。科学厘定我国“新能源矿产目录”,对于保障国家能源安全和经济安全意义重大。首先,界定了新能源、新能源“产-储-运-用”体系、新能源矿产的概念,据此进一步提出了涵盖重要性、关键性及新能源领域对矿产需求影响程度3个维度的中国“新能源矿产目录”评价体系和评价方法;然后,按照“产-储-运-用”的4大环节梳理出新能源领域主要使用的43种矿产作为备选矿产清单,并通过系统评价确定了涵盖锂、铜、钒、硅(高纯石英)、钕、镝、镨、铽、铀、铂等19种矿产的中国“新能源矿产目录”;最后,分析了我国新能源矿产的供应保障情况,指出我国8种新能源矿产高度紧缺、依赖进口,另外11种矿产目前能够保障需求,未来极有可能面临供不应求、依赖进口的局面,亟需提前布局,加大勘查开发和投资力度,确保国家新能源矿产资源稳定供应。

考虑乘客起讫点选择的可变线路公交服务设计优化

可变线路公交可以在一定距离内偏离固定线路接送乘客,具有提高公共交通服务可达性的优势。然而,公交车过多访问非站点处的乘客,会增加车辆的行驶距离与时间,导致车内和站点等候乘客时间延误。因此,本文提出以浮动票价来调控乘客的接送需求,优化可变线路公交的固定站点个数、发车间隔和基础票价以实现单位时间内的社会福利(运营商利润和消费者剩余之和)最大化。首先,本文利用连续近似法分别在无财政限制(允许盈利赤字)和有财政限制(在财政补贴下确保运营不亏损)的情况下构建了最优化模型;其次,通过BONMIN求解器,求出无财政限制的模型的最优固定站点个数、发车间隔和基础票价;最后,通过对潜在出行需求、服务区域的矩形长宽比、票价调整系数及车容量等进行灵敏度分析,验证了模型的有效性。结果表明,单位时间财政补贴存在两个阈值。实例分析表明,对洛杉矶MTA646路夜间公交分别实行统一票价和差异化票价时,潜在出行需求存在一个阈值。当潜在出行需求超过120人/h时,票价调整系数为1时对单位时间社会福利的优化度比票价调整系数为0.2、0.4、0.6和0.8时更高,约为1%。本研究为可变线路公交系统的服务设计与财政补贴计算提供了重要参考依据。

区域轨道交通跨线站配线方案研究

“四网融合”发展背景下,区域轨道交通网络化运营成为重要发展趋势,而跨线站则是实现不同轨道交通线路互联互通的关键节点,因此有必要对跨线站设计进行探究。从优化车站运输组织出发,对跨线站配线方案进行研究,为实际配线布设提供参考。首先,以跨线运营模式为研究对象,根据跨线前后信号制式异同,将跨线分为同信号制式跨线和跨信号制式跨线,分析两种跨线模式列车作业种类及流程,并研究两种模式下行车组织、承载客流形式、应急管理等因素对于车站配线设置的相关需求。之后,结合配线需求,针对同信号制式和跨信号制式跨线站,分别提出了配线布置原则。最后,基于布置原则,在进一步分析两种跨线站列车作业特征基础上,研究并提出适用于不同车站构型、不同客流特征的典型配线设置方法,并进一步考虑运输组织适应性、建筑规模、工程量等因素提出适应不同实际运营场景的建议方案。通过研究,对于同信号制式跨线站,建议以在发车端设单渡线、交叉渡线等配线为主;对于跨信号制式跨线站,结合当前技术条件建议增设到发线,并根据实际需求设置折返线等其他配线。

考虑需求不确定的响应式接驳公交自适应发车策略优化

传统公交系统融合网约出行的模式之一是需求响应式接驳公交,它定位于连接枢纽站点(如地铁车站、铁路车站或机场),服务客流的集散,其需求响应服务主要指灵活线路的门到门接送,但在发车策略方面仍主要沿用传统的基于时刻表或频率的运营方案。在乘客到达或需求订单不确定的情形下,固定发车间隔可能导致系统过饱和或低饱和等问题,为此,本文提出自适应发车策略,根据乘客累计到达量动态确定发车决策。具体地,引入载客量目标作为发车阈值,称为固定发车阈值和时变发车阈值,前者的发车阈值固定不变,而后者的发车阈值则随时间逐渐降低,对此,构建以期望广义系统成本最小化为目标的数学规划问题,并利用网格搜索方法获得最优解。数值分析结果表明,时变发车阈值模型相比于传统的等间隔发车模型和固定发车阈值模型在需求均值较低或变异系数较高的场景下优势显著,其广义系统成本节约百分比最高可达18%。灵敏度分析表明上述模型的性能也受到乘客的时间价值影响。自适应发车模型具有较广的应用潜力,适当修改后可用于其他形式的公共交通系统。

基于改进浮动单元的城市职住平衡时间尺度估计——以广州市为例

已有研究对城市职住平衡的测度往往存在可塑性面积单元问题,且忽略了交通网络在职住联系中的媒介作用。提出一种改进的浮动单元法,构建基于道路和城市轨道交通网络的数据集,以时间为职住分析尺度生成浮动单元,运用手机信令数据对职住平衡进行测度。以广州市为例,对就业中心和居住区的职住平衡时间尺度进行估计。研究发现:广州市中心城区职住平衡时间尺度分布呈圈层式空间特征,职住平衡时间尺度从一级就业中心向外围先减小再增大;城市轨道交通缩小了就业中心的职住平衡时间尺度;一级、二级(不处于一级就业中心的辐射范围内)和三级就业中心的职住平衡时间尺度分别为32~40 min、14~28 min和10~20 min,而居住组团的职住平衡时间尺度主要依附于就业中心且受到城市轨道交通的影响。最后,提出在合适的时间尺度下对职住空间结构进行评估和优化住房和就业等资源配置,并重视城市轨道交通对职住空间结构的影响。

大型枢纽车站铁路信号系统增改工程设计与施工

新建广州白云火车站是未来广州市的重要交通枢纽,其规模庞大,情况复杂。该文结合现场施工实际状况,以广州白云火车站改造为例,详细描述白云火车站在新建和改建过程中,信号系统具体设计思路和施工总体技术方案,针对施工可能出现的问题,制定相应措施,确保改造工程顺利进行,为今后轨道交通枢纽信号系统施工积累经验。

基于异构数据特征的城市轨道交通OD客流短时预测方法

城市轨道交通起讫点(origin-destination,OD)客流短时预测在智能交通系统中意义重大,它为交通管控策略实施以及出行者出行选择提供了重要的决策依据。卷积神经网络被广泛用于交通数据空间相关性提取,但其平移不变性与局部敏感性导致该方法更重视局部特征而忽视全局特征。本研究构建了基于注意力机制的异构数据特征提取机模型(heterogeneous data feature extraction machine,HDFEM)以实现OD矩阵空间相关性的全局感知。该模型从时空特征和用地属性特征出发,构造异构数据OD时空张量与地理信息张量,依托模型张量编码层对异构数据张量进行分割与编码,通过注意力机制连接各张量块特征,提取OD矩阵中各个部分间的空间相关性。该方法不仅实现了异构数据与OD客流数据的融合,还兼顾了卷积神经网络模型未能处理的OD矩阵远距离特征,进而帮助模型更全面地学习OD客流的空间特征。对于OD时序特性,该模型使用了长短时记忆网络来处理。在杭州地铁自动售检票系统(auto fare collection,AFC)数据集上的实验结果表明:HDFEM模型相对于基于卷积神经网络的预测模型,其均方误差、平均绝对误差与标准均方根误差分别下降了4.1%,2.5%,2%,验证了全局OD特征感知对于城市轨道交通OD客流预测的重要性。

梯级泵站事故停机输水明渠水力过渡过程研究

为解决梯级泵站系统因超负荷、大流量、高水位运行出现垮渠、跳闸停机等事故,而导致水力过渡过程中出现进水前池被抽干或漫顶等问题,以甘肃省景泰川电力提灌二期工程长距离输水明渠为研究对象,在多梯级泵站事故停机产生溢流的工况下,基于Realizable k-ε和VOF模型进行数值模拟计算,分析景电二期工程1#~7#干渠在调蓄系统作用下,不同渠长、坡降的水面线以及水力振荡分布规律。结果表明:泵站停机后水位出现升降交替的水力振荡现象,影响各泵站波峰水位高度不一致的主要原因是渠道坡降;不同参数特征的渠道壅水波运动的回溯距离不同,溢流堰上发生溢流的时间主要在第一次水位振荡过程中。