Urban Rail Transit最新文献

{"title":"Research on Vibration Characteristics of a Flexible Vehicle-Ladder Track System","authors":"Huan Wang, Aijun Gu, Qiang Fan, Xing Xing, Jingyu Liu","doi":"10.1007/s40864-023-00209-x","DOIUrl":"https://doi.org/10.1007/s40864-023-00209-x","url":null,"abstract":"<p>As a means of vibration reduction, the ladder track has seen broad implementation in urban rail transit. However, issues such as increased vibration noise, rail corrugation, and fastener failure have been observed in certain sections of the ladder track during later operation. To investigate the mechanisms behind these phenomena and provide comprehensive insights into the system's response to various operational conditions, this study employed vehicle-track coupled dynamic theory to establish a three-dimensional finite element model of the flexible vehicle-ladder track system. The vibration transmission and dynamic response characteristics of the vehicle-ladder track system were analyzed. The findings revealed that the vehicle-track resonance and anti-resonance phenomena were more prominent in the medium- to low-frequency range. At specific frequencies, the wheelset exhibited various vibration modes, and the fastener force was found to closely correlate with the ladder vibration mode. Furthermore, the influence of speed on diverse components of the vehicle-ladder track system, in terms of maximum vibration and the dominant vibration frequency range, differed considerably. This study provides a more comprehensive and reasonable exploration of the modeling and dynamic behavior of vehicle-ladder track systems.</p>","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"107 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139507222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of Insulated Rail Joints Based on Gap Value Measurement","authors":"Aldo La Placa, Francesco Freddi, Felice Giuliani","doi":"10.1007/s40864-023-00206-0","DOIUrl":"https://doi.org/10.1007/s40864-023-00206-0","url":null,"abstract":"<p>The monitoring of an IRJ would allow targeted maintenance to be carried out, reducing the problems caused by its potential failures. The authors present the results of a test field investigation, that involved the installation of seven longitudinal displacement sensors that continuously record the gap value of insulated rail joints (IRJs). The monitoring of an IRJ would allow targeted maintenance to be carried out, reducing the problems caused by its potential failures. The studied monitoring system was installed in a station of the suburban railway line within the metropolitan city of Bologna (Italy). Analysis of low-and high-frequency recordings was performed. In particular, low-frequency acquisition was used to fit a statistical predictive model that detects a deviation from a standard behaviour and may evidence anomalies. For the high-frequency acquisitions (registered during train passage) some representative quantities, that can provide macroscopic indicators of loss of joint stiffness, were computed. Although gap measurement alone is not exhaustive for identifying all possible failure scenarios, the data acquired by these monitoring devices can represent a possible immediate monitoring solution, based on already available instrumentation, to provide user-friendly predictive analysis systems aiming at improving the railway maintenance.</p>","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"79 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138681383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-axisymmetric Modeling of a Moving Heat Source for Thermal Stress and Fatigue Analysis of Railway Vehicle Disc Brakes","authors":"Kejela Temesgen Deressa, Demiss Alemu Ambie","doi":"10.1007/s40864-023-00207-z","DOIUrl":"https://doi.org/10.1007/s40864-023-00207-z","url":null,"abstract":"<p>Railroad vehicles require the use of disc brakes for safety purposes, however, the brakes are susceptible to thermal stress, which ultimately shortens their lifespan. Hence, to accurately predict the life of railway disc brakes in thermal load simulations, the availability of a model that considers spatial and temporal variations of temperature and thermal stress is essential. A non-axisymmetric moving heat source model was successfully developed to address spatial temperature variations (Deressa and Ambie in Urban Rail Transit 8(3–4):198–216, 2022. 10.1007/s40864-022-00176-9), and this study aims to extend this model to predict thermal stress and fatigue life, and assess its effectiveness. The analysis includes braking time thermal analysis, cooling time thermal analysis, and structural analysis. Spatially varying temperature is incorporated into the structural analysis to calculate thermal stress and strain. A fracture mechanics-based fatigue life estimation method is applied to critical areas of the friction surface. The model is implemented on two braking conditions (service and emergency) and two disc geometries (actual and modified). The model successfully resolves spatial heat considerations by estimating maximum stress variations of up to 46 MPa along the disc circumference. Stress differences of 3 MPa and 6 MPa are observed between the leading and trailing edges of the pad trace during late and mid-braking times, respectively. Fatigue life results identify critical positions and directions for fatigue life initiation. Additionally, these results are in accord with previous observations available in the literature. The proposed model can be easily implemented in various sliding friction applications such as drum brakes, engine pistons/cylinders, and camshafts.</p>","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"82 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138629700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and Prediction of Dockless Shared Bike Demand Evolving Around Urban Rail Transit Stations: Case Study in Shenzhen, China","authors":"Yingping Zhao, Yiling Wu, Xinfeng Zhang, Yaowei Wang, Zhenduo Zhang, Hongyu Lu, Dongfang Ma","doi":"10.1007/s40864-023-00204-2","DOIUrl":"https://doi.org/10.1007/s40864-023-00204-2","url":null,"abstract":"<p>The emergence of dockless shared bikes (DSB) has led to their use as an important transfer mode to urban rail transit (URT) stations. However, in highly populated areas such as subway stations in peak hours, there is increasing concern about the imbalance between the demand and supply of shared bikes. To promote smoother subway transfer trips using shared bikes, it is very important to estimate the DSB demand, especially the disparity in the volume of bike pick-up and drop-off demand around subway stations. This research first utilizes the Shenzhen metro usage data and DSB usage data, analyzes data regarding subway and shared bike usage, discusses their potential transfer uses, and finds great disparity in DSB demand between different subway stations. The catchment area method is used to estimate bike usage as a potential transfer mode to the subway, where the catchment area is defined as a radius of 150 m from the subway station center. The DSB trip demand is categorized into two types: pick-up and drop-off. The most recent deep learning method, adaptive graph convolutional recurrent network (AGCRN), is used to predict the DSB demand more accurately because of its ability in enabling the modeling of relationships between entities in a self-adapted graph, and the prediction is compared with long short-term memory (LSTM), spatiotemporal neural network (STNN), diffusion convolutional recurrent neural network (DCRNN), and Graph WaveNet. Results show that methods with graphs (STNN, DCRNN, Graph WaveNet, and AGCRN) perform better than LSTM, and methods with adaptive graphs (Graph WaveNet and AGCRN) outperform methods with static graphs in terms of mean absolute error (MAE), root-mean-square error (RMSE), and mean absolute percentage error (MAPE). DSB prediction results show that AGCRN performs the best in this study. More data, particularly land use data and URT station volume data, are expected to improve the predictive accuracy of the method due to potentially improved graph representation of station characteristics and subway station volume correlations. And with more accurate prediction results, it will be possible to achieve a better balancing strategy for bike operation optimization for better bike usage, and thus for a higher transfer rate of DSB to subway.</p>","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"40 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138514975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Time Series Decomposition and Reinforcement Learning Ensemble Method for Short-Term Passenger Flow Prediction in Urban Rail Transit","authors":"Jinxin Wu, Deqiang He, Xianwang Li, Suiqiu He, Qin Li, Chonghui Ren","doi":"10.1007/s40864-023-00205-1","DOIUrl":"https://doi.org/10.1007/s40864-023-00205-1","url":null,"abstract":"<p>Short-term passenger flow prediction (STPFP) helps ease traffic congestion and optimize the allocation of rail transit resources. However, the nonlinear and nonstationary nature of passenger flow time series challenges STPFP. To address this issue, a hybrid model based on time series decomposition and reinforcement learning ensemble strategies is proposed. Firstly, the improved arithmetic optimization algorithm is constructed by adding sine chaotic mapping, a new dynamic boundary strategy, and adaptive T distribution mutations for optimizing variational mode decomposition (VMD) parameters. Then, the original passenger flow data containing nonlinear and nonstationary irregular changes of noise is decomposed into several intrinsic mode functions (IMFs) by using the optimized VMD technology, which reduces the time-varying complexity of passenger flow time series and improves predictability. Meanwhile, the IMFs are divided into different frequency series by fluctuation-based dispersion entropy, and diverse models are utilized to predict different frequency series. Finally, to avoid the cumulative error caused by the direct superposition of each IMF’s prediction result, reinforcement learning is adopted to ensemble the multiple models to acquire the multistep passenger flow prediction result. Experiments on four subway station passenger flow datasets proved that the prediction performance of the proposed method was better than all benchmark models. The excellent prediction effect of the proposed model has important guiding significance for evaluating the operation status of urban rail transit systems and improving the level of passenger service.</p>","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"25 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138514970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on Time-Based Fare Discount Strategy for Urban Rail Transit Peak Congestion","authors":"Xiaobing Ding, Chen Hong, Jinlong Wu, Lu Zhao, Gan Shi, Zhigang Liu, Haoyang Hong, Zhengyuan Zhao","doi":"10.1007/s40864-023-00203-3","DOIUrl":"https://doi.org/10.1007/s40864-023-00203-3","url":null,"abstract":"Abstract To alleviate peak-hour congestion in urban rail transit, this study proposes a new off-peak fare discount strategy to incentivize passengers to shift their departure time from peak to off-peak hours. Firstly, a questionnaire survey of Shanghai metro passengers is conducted to analyze their willingness to change departure time under different fare strategies. Secondly, based on the survey results, a time-differentiated fare discount model is constructed, considering both the company’s revenue and passengers’ travel benefits, and with the optimization objective of achieving balanced peak-hour and off-peak-hour train loads throughout the day. Subsequently, a genetic algorithm with nested fmincon functions is designed and combined with the actual data of Shanghai rail transit line 9 for arithmetic analysis. Finally, the effectiveness of the model is validated using the survey data. The research results show that the off-peak fare discount strategy can incentivize 6.88% of passengers traveling in the morning peak and 6.66% of passengers traveling in the evening peak to shift to off-peak travel. This research provides theoretical support and decision-making guidance for implementing time-differentiated pricing in urban rail transit systems.","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135992918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remembering and Remapping Breslaff: Resurfacing German and Queer Topographies in Contemporary Polish Literature","authors":"Alicja Kowalska","doi":"10.5070/t714162193","DOIUrl":"https://doi.org/10.5070/t714162193","url":null,"abstract":"This article focuses on the role of contemporary Polish literature in bringing back that which has been repressed under communism: the Germanness of the so-called “regained territories”, i.e. territories that became Polish due to the changes of national borders after the Second World War, as well as the marginalized queer life. I discuss two novels that feature the city of Wrocław, formerly German Breslau: Marek Krajewski’s Death in Breslau (1999) and Michał Witkowski’s Lovetown (2004). My analysis draws parallels between bringing back the German past of the city and remembering queer life during communism in fiction. Marek Krajewski situates the plot of his highly popular crime novel in Breslau in the 1930s. By doing so, he fictionally recreates the former German city which allows the reader to rediscover its past and foreign layer. Michał Witkowski’s prose performs a similar task by describing parts of the city that were central to queer culture but hidden from the experience of the “general public” under communism. I argue that remembering takes effect through remapping and that this literary remapping destabilizes the narrative about Polish culture as a homogeneous block of monolingualism, Catholicism, and heteronormativity. Furthermore, the fictional topographies of the German Breslau and the queer Wrocław alter the existing geospace by overlaying a suppressed otherness onto it.","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135829950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inga Iwasiów: Bambino (2008)","authors":"Inga Iwasiów, Karolina May-Chu, Karolina Hicke","doi":"10.5070/t714162203","DOIUrl":"https://doi.org/10.5070/t714162203","url":null,"abstract":"","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135792992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“What Gender is Your Hair Color”","authors":"Irina Nekrasov/a, Nat Modlin","doi":"10.5070/t714162205","DOIUrl":"https://doi.org/10.5070/t714162205","url":null,"abstract":"","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135828258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In den Häusern der anderen: Spüren deutscher Vergangenheit in Westpolen","authors":"Karolina Kuszyk, Bernhard Hartmann","doi":"10.5070/t714162204","DOIUrl":"https://doi.org/10.5070/t714162204","url":null,"abstract":"","PeriodicalId":44861,"journal":{"name":"Urban Rail Transit","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135829042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}