Functional Characteristics of Beijing Subway Stations Based on POI Data:Taking Beijing Metro Line 6 as An Example

Urban subway station is a key node related to urban social,political,economic and cultural activities.There are some differences in the location,function orientation,land use and flow characteristics of different types of stations in the city.This paper mainly used Tyson’s edge,kernel density analysis,chart analysis and other methods to classify the functional types of 412,393 POI data of 26 stations along Metro he results showed that the spatial distribution of Beijing Metro Line 6 was mainly divided into 3 categories,subway stations were divided into 4 categories.Among them,type A sites were divided into composite and single types,and the distribution characteristics of the 6 types of sites were quite different.Based on the qualitative and quantitative analysis of POI point data,this method can quickly classify and analyze the characteristics of stations along Line 6 in Beijing,which also has theoretical and practical value for the planning of urban subway lines.

Comparative Analysis of the Factors Influencing Metro Passenger Arrival Volumes in Wuhan, China, and Lagos, Nigeria: An Application of Association Rule Mining and Neural Network Models

This study explores the factors influencing metro passengers’ arrival volume in Wuhan, China, and Lagos, Nigeria, by examining weather, time of day, waiting time, travel behavior, arrival patterns, and metro satisfaction. It addresses a significant research gap in understanding metro passengers’ dynamics across cultural and geographical contexts. It employs questionnaires, field observations, and advanced data analysis techniques like association rule mining and neural network modeling. Key findings include a correlation between rainy weather, shorter waiting times, and higher arrival volumes. Neural network models showed high predictive accuracy, with waiting time, metro satisfaction, and weather being significant factors in Lagos Light Rail Blue Line Metro. In contrast, arrival patterns, weather, and time of day were more influential in Wuhan Metro Line 5. Results suggest that improving metro satisfaction and reducing waiting times could increase arrival volumes in Lagos Metro while adjusting schedules for weather and peak times could optimize flow in Wuhan Metro. These insights are valuable for transportation planning, passenger arrival volume management, and enhancing user experiences, potentially benefiting urban transportation sustainability and development goals.

Assessment of the Influence of Tunnel Settlement on Operational Performance of Subway Vehicles

In the realm of subway shield tunnel operations,the impact of tunnel settlement on the operational performance of subway vehicles is a crucial concern.This study introduces an advanced analytical model to investigate rail geometric deformations caused by settlement within a vehicle-track-tunnel coupled system.The model integrates the geometric deformations of the track,attributed to settlement,as track irregularities.A novel“cyclic model”algorithm was employed to enhance computational efficiency without compromising on precision,a claim that was rigorously validated.The model’s capability extends to analyzing the time-history responses of vehicles traversing settlement-affected areas.The research primarily focuses on how settlement wavelength,amplitude,and vehicle speed influence operational performance.Key findings indicate that an increase in settlement wavelength can improve vehicle performance,whereas a rise in amplitude can degrade it.The study also establishes settlement thresholds,based on vehicle operation comfort and safety.These insights are pivotal for maintaining and enhancing the safety and efficiency of subway systems,providing a valuable framework for urban infrastructure management and long-term maintenance strategies in metropolitan transit systems.

Regenerative Braking Energy Recovery System of Metro Train Based on Dual-Mode Power Management

In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strategy is proposed.Firstly,the construction of the hybrid regenerative braking energy recovery system is explained.Then,based on the power demand of low-voltage load in metro stations,a dual-mode power management strategy is proposed to allocate the reference power of each system according to the different working conditions,and the control methods of each system are set.Finally,the correctness and effectiveness of the dual-mode strategy are verified through simulation,and the proposed braking energy utilization scheme is compared with other singleform utilization schemes.The results illustrate that the hybrid system with the dual-mode strategy can effectively recycle the regenerative braking energy of metro train and inhibit the busbar voltage fluctuation;the proposed braking energy utilization scheme has certain advantages on energy recovery and DC bus voltage stabilization compared with other single-form schemes;the proposed power management strategy can correctly allocate the reference power of each system with a lower construction cost.

Mechanical responses of underground carriageway structures due to construction of metro tunnels beneath the existing structure:A case study

To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.

Comparative Analysis of Metro Passengers’Mobility Patterns and Jobs-housing Balance of Metropolitan

The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the urban space.In this paper,we use metro smart card data from two Chinese metropolises,Shanghai and Shenzhen.Five metro mobility indicators are introduced,and association rules are established to explore the mobility patterns.The proportion of people entering and exiting the station is used to measure the jobs-housing balance.It is found that the average travel distance and duration of Shanghai passengers are higher than those of Shenzhen,and the proportion of metro commuters in Shanghai is higher than that of Shenzhen.The jobs-housing spatial relationship in Shenzhen based on metro travel is more balanced than that in Shanghai.The fundamental reason for the differences between the two cities is the difference in urban morphology.Compared with the monocentric structure of Shanghai,the polycentric structure of Shenzhen results in more scattered travel hotspots and more diverse travel routes,which helps Shenzhen to have a better jobs-housing balance.This paper fills a gap in comparative research among Chinese cities based on transportation big data analysis.The results provide support for planning metro routes,adjusting urban structure and land use to form a more reasonable metro network,and balancing the jobs-housing spatial relationship.

Fatigue research of metro car body based on operational loads

Purpose–The principle of infinite life design currently directs fatigue resistance strategies for metro car bodies.However,this principle might not fully account for the dynamic influence of operational loads and the inevitable presence of defects.This study aims to integrate methods of service life estimation and residual life assessment,which are based on operational loads,into the existing infinite life verification framework to further ensure the operational safety of subway trains.Design/methodology/approach–Operational loads and fatigue loading spectra were determined through the field test.The material test was conducted to investigate characteristics of the fracture toughness and the crack growth rate.The fatigue strength of the metro car body was first verified using the finite element method and Moore–Kommers–Japer diagrams.The service life was then estimated by applying the Miner rule and high-cycle fatigue curves in a modified form of the Basquin equation.Finally,the residual life was assessed utilizing a fracture assessment diagram and a fitted curve of crack growth rate adhered to the Paris formula.Findings–Neither the maximum utilization factor nor the cumulative damage exceeds the threshold value of 1.0,the metro car body could meet the design life requirement of 30 years or 6.6 million km.However,three out of five fatigue key points were significantly influenced by the operational loads,which indicates that a single fatigue strength verification cannot achieve the infinite life design objective of the metro car body.For a projected design life of 30 years,the tolerance depth is 12.2 mm,which can underscore a relatively robust damage tolerance capability.Originality/value–The influence of operational loads on fatigue life was presented by the discrepancy analysis between fatigue strength verification results and service life estimation results.The fracture properties of butt-welded joints were tested and used for the damage tolerance assessment.The damage tolerance life can be effectively related by a newly developed equation in this study.It can be a valuable tool to provide the theoretical guidance and technical support for the structural improvements and maintenance decisions of the metro car body.

Classification of Service Functions in the Life Circle of Beijing Subway Line 7

As a key node for the surrounding area,metro stations are closely connected with the surrounding urban space and develop cooperatively.Different types of metro stations have differences in land use and functional positioning.This paper mainly used the methods of Tyson polygon,kernel density analysis and correlation analysis,based on POI data,to classify the stations of Beijing Metro Line 7.This paper made a detailed analysis of commercial subway stations,and analyzed the distribution characteristics of commercial metro stations on Line 7.

Sustainable Urban Mobility: (A)Synchrony between Subway Systems

The present study analyses the differences between the subways systems of two cities, Lisbon (Portugal) and Brasília (Brazil), verifying the extent to which their subway systems are spatially integrated with the respective urban fabric-which would promote a better synchrony in terms of economy and sustainability. For interpreting the data, the methodology and tools of the Theory of the Social Logic of Space were used, by means of axial maps, researching the relationship between the constructed and empty (public spaces) areas of the urban structures. Based on the findings, meaningful differences between the subway systems and the configuration of urban spaces were observed, as a product of specific design matrixes. In Lisbon, the mobility associated to the subway seems to be encouraged by the integration of the system with the potential for movement provided by the urban tissue (making the secondary centralities articulated with the subway stations more dynamic). In Brasilia, however, there are several difficulties for such mobility, due to the predominant role of the empty spaces in the city which weakens the gathering potential of such areas, despite the fact that such articulation with secondary centralities is also present there.

Construction Technology of Pile Foundation for Subway Tunnel Crossing Bridge

Urban infrastructure has become more complex with the rapid development of urban transportation networks.In urban environments with limited space,construction of facilities like subways and bridges may mutually influence each other,especially when subway construction requires passing under bridges.In such cases,pile foundation replacement technology is often necessary.However,this technology is highly specialized,with a lengthy and risky construction period,and high costs.Personnel must be proficient in key technical aspects to ensure construction quality.This article discusses the technical principle,construction process,and core technology of pile foundation replacement,along with the application of this technology in subway tunnel crossing bridge projects,supported by engineering examples for reference.

Automatic Sensing and Detection for Subway Tunnel Pathologies

Subway tunnels often suffer from surface pathologies such as cracks,corrosion,fractures,peeling,water and sand infiltration,and sudden hazards caused by foreign object intrusions.Installing a mobile visual pathology sensing system at the front end of operating trains is a critical measure to ensure subway safety.Taking leakage as the typical pathology,a tunnel pathology automatic visual detection method based on Deeplabv3+(ASTPDS)was proposed to achieve automatic and high-precision detection and pixel-level morphology extraction of pathologies.Compared with similar methods,this approach showed significant advantages and achieved a detection accuracy of 93.12%,surpassing FCN and U-Net.Moreover,it also exceeded the recall rates for detecting leaks of FCN and U-Net by 8.33%and 8.19%,respectively.

Discussion on Construction Technology of Subway Tunnel Expansion under Bridge Foundation

As the urban populations grow,the number and size of subway construction projects are increasing while also meeting higher construction standards.So,subway construction projects must have a better understanding of construction technology.This article focuses on the construction technology of the subway tunnel expansion under the bridge foundation.By analyzing the engineering characteristics of the bridge foundation and using a project as an example,this article provides a detailed discussion of the construction process of tunnel expansion under a bridge foundation.This article aims to serve as a reference for subway tunnel construction in China to ensure the key points of construction technology are understood,thus improving construction quality and laying a solid technical foundation for the sustainable development of urban rail engineering.

地铁大语言模型垂直问答系统MetroGPT

为解决城市轨道交通大系统中各个运行层级间不协调与信息资源浪费的问题,以地铁系统为原型,分析地铁大系统的运作机制,设计易于实现的地铁大模型问答系统(MetroGPT)。MetroGPT是基于大语言模型(LLM)构建的地铁大语言模型垂直问答系统,以LangChain为设计框架,针对特定场景定制不同的AI智能体完成特定任务。基于现有的6种大语言模型制作垂域智能体,使用改进的德尔菲法设计评估流程,通过德尔菲法的评分结果选出与地铁某类垂域知识最为匹配的大语言模型引擎。研究结果表明:MetroGPT提供1种解决地铁运行系统中层级信息闭塞、交流不充分的方法,为运营方、乘客、服务人员提供1个三方交流平台,在不同条件下针对需求制定合乎规范与实际的解决方案。通过分析现有技术和挑战,提出1种结合知识图谱和大语言模型的问答系统设计方案,并讨论其在地铁运营中的具体应用场景和潜在价值。

华为Metro 1000在光纤通信课程中的应用

近年来随着高速数据传输的需求猛增,光传输网作为主干传输网的核心得到了快速发展,而SDH传输设备在光传输网中获得了广泛的应用;华为作为世界第二大通信设备制造商,其SDH设备在市场上占有最大份额;将华为SDH传输设备Metro 1000应用于光纤通信课程实验中不仅巩固了课堂所学的理论知识,更提高了学生的实际操作和设计能力,收到了较好的实验效果。

G.metro技术及其在5G移动前传网络中的应用

介绍了G.metro标准、特性以及关键技术,分析了G.metro技术在5G移动前传网络中的应用及优势。

基于Metro平台的LBS扩展应用

在移动互联网飞速发展的今天,传统旅游服务已经越来越不适应当前信息化旅游服务环境,对此需对现有的旅游资源进行充分整合,形成一种游客可以自由选择的平台,同时充分利用现代信息科技,发挥电子商务、旅游网站的作用,打破以往单一的经营模式,提供功能相当、具有更高诚信度的服务。提出基于微软Metro平台并结合LBS技术的现代化旅游信息服务系统,以适应当前信息化旅游服务环境。

基于GIS的合肥市BRT和Metro交通可达性研究

评价了合肥市中心城区的BRT和在建Metro线路对可达性的影响。基于GIS网络分析模拟复杂的多模式交通网络,应用修正潜能模型指标度量了居民区与CBD、与商业金融中心、与行政中心以及与工业区的可达性,对比有无BRT和Metro两种情景下的可达性变化。研究结果表明:在有BRT和Metro时,居民区至CBD的可达性均值变化幅度为45.8%,出行时间从65.5min减至35.5min;居民区至商业金融中心的可达性均值变化幅度为45.7%,时间从74.8min减至40.6min;居民区至行政中心的可达性均值变化幅度为18.9%,时间从104.7min减至84.9min;居民区至工业区的可达性均值变化幅度为37.4%,时间从92.1min减至57.7min。BRT和Metro线路显著地节省了居民出行时间,改善了城市边缘区域的交通可达性,其中经开区的可达性变化幅度最高,其次是滨湖新区、高新区和东区、老城区、南区、西区和北区。

WP8 Metro开发

Windows 8是微软公司于2012年推出的继Windows7之后的新一代电脑操作系统,采用与Windows Phone 8相同的NT内核,该操作系统除了具备微软适用于笔记本电脑和台式机平台的传统窗口系统显示方式外,还特别强化适用于触控屏幕的平板电脑设计,使用了新的接口风格Metro,这种应用程序和我们传统看到的Windows应用最大的不同就是它是为触摸屏设备而设计的。

地铁曲线地段扣件刚度对钢轨波磨的影响实测与仿真分析

钢轨波磨是地铁典型病害之一。为抑制钢轨波磨的产生,对某地铁线路的钢轨波磨特征、轨道刚度进行测试,并基于摩擦自激振动理论,研究了扣件刚度对钢轨波磨的影响。结合实测与仿真结果,提出了钢轨波磨控制措施,并通过后续测试对治理效果进行评价。研究结果表明:该线路存在40 mm~60 mm典型波长的钢轨波磨,并且内轨钢轨波磨更为严重。轮轨系统的不稳定振动主要发生在内侧轮轨之间,且频率为445.38 Hz。增大扣件垂、横向刚度可以抑制该不稳定振动,降低轨道结构在400 Hz, 800 Hz频率下的动态响应。波磨治理1年后,内外轨的不平顺幅值并未有明显增长,钢轨波磨发展速度得到明显控制。研究结果可为既有线路钢轨波磨治理以及新建线路钢轨波磨预防提供参考。

移动激光扫描在地铁车站限界测量中的应用

为满足限界要求,地铁车站站台边缘与地铁列车之间存在一定的间隙,但可能发生乘客踏空风险。现需对车站区段的站台边缘至线路中心线距离现状进行快速普查,为更新改造提供决策数据。文章利用移动激光扫描技术快速获取车站段全断面点云,通过点云数据处理提取关键特征点,实现了对空间距离的非接触测量,经传统方法对比复核,验证了该方法的准确性。