scholarly journals Rules of incidental operation risk propagation in metro networks under fully automatic operations mode

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261436
Author(s):  
Wenying Chen ◽  
Jinyu Yang ◽  
Mohammad T. Khasawneh ◽  
Jiaping Fu ◽  
Baoping Sun

The frequent interruptions of network operation due to any incident suggest the necessity to study the rules of operational risk propagation in metro networks, especially under fully automatic operations mode. In this study, risk indicator computation models were developed by analyzing risk propagation processes within transfer stations and metro networks. Moreover, indicator variance rules for a transfer station and different structural networks were discussed and verified through simulation. After reviewing the simulation results, it was concluded that under the impacts of both sudden incident and peak passenger flow, the more the passengers coming from platform inlets, the longer the non-incidental line platform total train operation delay and the higher the crowding degree. However, train headway has little influence on non-incidental line platform risk development. With respect to incident risk propagation in a metro network, the propagation speed varies with network structure, wherein an annular-radial network is the fastest, a radial is moderately fast, and a grid-type network is the slowest. The conclusions are supposed to be supports for metro operation safety planning and network design.

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4008
Author(s):  
Błażej Doroszuk ◽  
Robert Król ◽  
Jarosław Wajs

This paper addresses the problem of conveyor transfer station design in harsh operating conditions, aiming to identify and eliminate a failure phenomenon which interrupts aggregate supply. The analyzed transfer station is located in a Polish granite quarry. The study employs laser scanning and reverse engineering methods to map the existing transfer station and its geometry. Next, a discrete element method (DEM) model of granite aggregate has been created and used for simulating current operating conditions. The arch formation has been identified as the main reason for breakdowns. Alternative design solutions for transfer stations were tested in DEM simulations. The most uncomplicated design for manufacturing incorporated an impact plate, and a straight chute has been selected as the best solution. The study also involved identifying areas of the new station most exposed to wear phenomena. A new transfer point was implemented in the quarry and resolved the problem of blockages.


2019 ◽  
Vol 1346 ◽  
pp. 012017
Author(s):  
PEI Chao ◽  
Wang Dalei ◽  
Wang Xiaofeng ◽  
RAN Mengbing ◽  
Wang Man

2011 ◽  
Vol 403-408 ◽  
pp. 1471-1474
Author(s):  
Jing Chen

Transferring plays an important role between different lines of urban rail transport and routine public transit. The convenience of a transfer station not only directly affects the efficiency of the whole traffic network, but also is a key factor that influences travel convenience. Based on GIS, through the study of the convenience at the 16 subway transfer stations in Beijing, the article tries to find the relationship of the evaluations on the transferring between metro-metro and metro-bus. Finally, by further clustering analysis on the spatial distributions of the transferring evaluations, this article reveals the existing problems of the layout of transfer stations and proposes several effective suggestions and countermeasures for them.


2013 ◽  
Vol 655-657 ◽  
pp. 2335-2339 ◽  
Author(s):  
Bi Hong Lu ◽  
Peng Hua ◽  
Zhen Liang Fu ◽  
Feng Gao

Based on the FMEA and risk assessment analysis method, authors proposed 25 kinds of failure modes about the door system of high-speed train, conducted a risk assessment from the risk grade and criticality. Four kinds of failure modes are obtained with the highest level of risk and criticality in the door system of high-speed train. They are control failure, communication failure, compensator failure and poor function. Four key components, affecting the door system safety of high-speed train, are identified in terms of door control unit, driving device, locking mechanism and platform compensator. Research outcomes can be used in analyzing the failure causes and specific solutions to reduce and avoid the high-speed train operation risk.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250962
Author(s):  
Yulong Chen ◽  
Zhizhu Lai ◽  
Zheng Wang ◽  
Dongyang Yang ◽  
Leying Wu

Many studies have considered the location of rural waste transfer stations, but most have omitted the impact of transportation network conditions. Traffic accessibility must be considered in optimizing the location of rural waste transfer stations, which is an important difference from the location of rural waste transfer stations. On the basis of previous studies, this study will consider the impact of traffic network on the optimization locations of waste transfer station in the rural areas. The objective of this study was to ensure the minimum Euclidean distance between the waste transfer station and the population center is the maximum, minimize the garbage transportation cost of each population center, construction costs for waste transfer stations, construction and upgrade costs for roads on a traffic network. A multi-objective facility location-network design model and an improved multi-objective simulated annealing algorithm was used to solve the problem. A detailed practical case study was used to illustrate the application of the proposed mathematical model. The results show that transportation network plays an important role in facility location optimization, and the improvement of traffic network conditions can greatly reduce waste transportation costs.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yujuan Sun ◽  
Guanghou Zhang ◽  
Huanhuan Yin

Passenger flow is increasing dramatically with accomplishment of subway network system in big cities of China. As convergence nodes of subway lines, transfer stations need to assume more passengers due to amount transfer demand among different lines. Then, transfer facilities have to face great pressure such as pedestrian congestion or other abnormal situations. In order to avoid pedestrian congestion or warn the management before it occurs, it is very necessary to predict the transfer passenger flow to forecast pedestrian congestions. Thus, based on nonparametric regression theory, a transfer passenger flow prediction model was proposed. In order to test and illustrate the prediction model, data of transfer passenger flow for one month in XIDAN transfer station were used to calibrate and validate the model. By comparing with Kalman filter model and support vector machine regression model, the results show that the nonparametric regression model has the advantages of high accuracy and strong transplant ability and could predict transfer passenger flow accurately for different intervals.


2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Sunarto . ◽  
Sudharto P. Hadi ◽  
Purwanto .

JEJAK KARBON PENGOLAHAN SAMPAH DI tps tlogomas malang Carbon Footprint of Solid Waste Processing At TPS Tlogomas MalangSunarto1, Sudharto P. Hadi2, Purwanto31,2,3Program Doktor Ilmu Lingkungan Universitas DiponegoroAlamat korespondensi : Jl. Imam Bardjo, SH No. 3 Semarang 50241Email: 1) [email protected], 2) [email protected] sector is one of human activities that cause global warming. Decomposition of organic waste in landfill produces greenhouse gas emissions in the form of biogas consisting of methane and carbon dioxide. Solid waste processing in transfer station in the form of recycling and composting product potentially reduce carbon footprint, directly from the reduction in the volume of waste dumped in landfill and indirectly from the recovery of material. The purpose of this study was to determine the carbon footprint of waste processing at the transfer stations of Tlogomas Malang if developed several scenarios to enhance the capacity of processing. Life cycle approach is used to assess carbon footprint of waste management scenarios with the help of software SWM-GHG Calculator. The results showed that the processing of solid waste at current recycling rate of 40,57% – 80,41% (Status Quo) resulted in net carbon footprint of 1.147 ton CO2–eq /year. Increasing of processing capacity to 60 - 88% (Scenario 1) and 90 - 95% (Scenario 2) would reduce net carbon footprint to 801 ton  CO2–eq /year and427 ton CO2–eq/year respectively. If the processing of waste in transfer station of Tlogomas was discontinued (Scenario 3), net carbon footprint increased to 4,063 t CO2-eq/year.Keywords: carbon footprint, greenhouse gases, solid waste processing, life cycle analysis.AbstrakSektor persampahan merupakan salah satu kegiatan manusia yang menyebabkan pemanasan global. Proses dekomposisi sampah organik pada timbunan sampah menghasilkan emisi gas rumah kaca berupa biogas yang terdiri atas gas methana dan gas karbon dioksida. Pengolahan sampah di TPS untuk produk daur ulang dan kompos berpotensi mereduksi jejak karbon secara langsung dari penurunan volume sampah yang dibuang ke TPA dan secara tidak langsung dari pemulihan material sampah. Tujuan penelitian ini adalah untuk mengetahui jejak karbon pengolahan sampah di TPS Tlogomas di Kota Malang jika dikembangkan beberapa skenario pengolahan untuk meningkatkan kapasitas pengolahan sampah yang telah dilakukan selama ini. Pendekatan daur hidup digunakan untuk menaksir jejak karbon dari beberapa skenario pengolahan sampah di TPS dengan bantuan perangkat lunak SWM-GHG Calculator. Hasil analisis menunjukkan bahwa pengolahan sampah pada saat ini dengan tingkat daur ulang sampah sebesar 40,57% – 80,41% (Status Quo) menghasilkan jejak karbon bersih sebesar 1.147 ton CO2–eq/th. Peningkatan kapasitas pengolahan sebesar 60 – 88% (Skenario 1) dan 90 – 95% (Skenario 2) akan menurunkan jejak karbon bersih menjadi masing-masing sebesar 801 ton CO2–eq/th dan 427 t CO2–eq/th. Apabila pengolahan sampah di TPS Tlogomas dihentikan (Skenario 3), jejak karbon bersih yang dihasilkan meningkat menjadi 4.063 t CO2–eq/th.Kata kunci: jejak karbon, gas rumah kaca,  pengolahan sampah, analisis daur hidup.


2013 ◽  
Vol 409-410 ◽  
pp. 1311-1314 ◽  
Author(s):  
Yong Feng Shang ◽  
Lei Shan Zhou ◽  
Lu Tong ◽  
Chang Jun Cai

Under the background of the urban mass transit becoming network increasingly, time coordination of the first and last trains becomes the important part of urban mass transit network operation, and has special significance. This paper firstly ascertains the time range of first and last running of trains and analyzes from two aspects. Then find the time quantum that the passengers and companies all accept. The paper analyzes the departed principle of networked first and last running time of trains, the target is the minimum of the passengers total loss of time at the transfer stations, setting up a multiple-direction trains transfer mathematical model that achieves attainability and rationality for transferring among different lines and getting a local optimal solution by using the method of iteration, and the optimal solution is within the feasible region and fits actual situations. Lastly a specific urban rail network is taken as an example to check the model and algorithm.


2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Hanchuan Pan ◽  
Zhigang Liu ◽  
Hua Hu

By considering the difference between a car driver’s route choice behavior on the road and a passenger’s route choice behavior in urban rail transit (URT), this paper proposes an enhanced Dynamic User Optimal (DUO) passenger flow assignment model for metro networks. To capture realistic URT phenomena, the model has integrated the train operation disturbance constraint. Real passenger and train data are used to verify the proposed model and algorithm. The results indicate that the DUO-based model is more suitable for describing passenger route choice behavior under uncertain conditions compared to a static model. Moreover, this paper found that passengers under oversaturated conditions are more sensitive to train operation disturbances compared to undersaturated passengers.


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