• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1701-1708
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• 2011

A typical day in the subway transportation is used by hundreds of thousands are also concerned about the safety of the various workrooms with high underground fire or other less than in the subway users could be damaging even to be raised and there. In 2010, in fact, room air through vents in the fire because smoke and toxic gas accident victims, and train service suspended until such cases are often reported. In response to these incidents in subway stations, even if the latest IT technology, wireless sensor network technology and intelligent video surveillance technology by integrating fire and structural integrity, such as a comprehensive integrated surveillance system to monitor the development of intelligent urban transit system and are under study. In this study, prior to the application of the monitoring system into the field stations, authors carried out the ZigBee-based wireless sensor networks performance analyzation in the Chungmuro station. The test results at a communications room and ventilation room of the station are summarized and analyzed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.202-210
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• 2018

Recently, the subway running in metro environments has a problem in securing the safety of passengers due to the failure of announcement in emergency situations such as breakdown, train accidents and power outage in the underground tunnels. Thus, there is a need to develop an emergency broadcasting system that can provide the announcement to all passenger cars in any emergency situations on the railway route. In this paper, the applicability of various wireless communication technologies for the emergency broadcasting system through the measurement campaign was examined in Seoul metropolitan subway. A WAVE(Wireless Access in Vehicular Environments) is communication technology that can use 5.9GHz dedicated frequency band without charge and it is possible to directly communicate between terminals over 200m without the help of additional relay. Especially, it confirms robust communication performance in the various metro environments, and therefore, it is considered to be suitable as a communication method of a radio-connected emergency broadcasting system for urban subway.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1399-1406
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• 2011

As a result of the examination analyzed loop type of Detecting the Broken Rail Monitoring System as a part of prevention of train derailment, installed in the Seoul Metro No. 2 subway line 98.51m section which is Samsung to Seolleung, we found that it is possible to detect crack location(Thermit welding: 48.18m) within the margin of error of ${\pm}1m$ accurately As analysis of the first day, third day, fifty day, and seventh day periodically, we found that Fresnel reflection happened where the crack location 48.18m. However other 3 branches show loss by bending of optical cable(spread reflection from the outside impact).

• Interaction and multiscale mechanics
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• v.1 no.1
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• pp.157-175
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• 2008

A brief review of the research works on ground vibrations caused by trains moving in underground tunnels is first given. Then, the finite/infinite element approach for simulating the soil-tunnel interaction system with semi-infinite domain is summarized. The tunnel is assumed to be embedded in a homogeneous half-space or stratified soil medium. The train moving underground is modeled as an infinite harmonic line load. Factors considered in the parametric studies include the soil stratum depth, damping ratio and shear modulus of the soil with or without tunnel, and the thickness of the tunnel lining. As far as ground vibration is concerned, the existence of a concrete tunnel may somewhat compensate for the loss due to excavation of the tunnel. For a soil stratum resting on a bedrock, the resonance peak and frequency of the ground vibrations caused by the underground load can be rather accurately predicted by ignoring the existence of the tunnel. Other important findings drawn from the parametric studies are given in the conclusion.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.404-408
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• 2007

본 논문에서는 지하철 선로상의 CCTV영상을 이용하여 열차의 인식 및 진출입유무를 검출하는 기법을 제안한다. 움직이는 열차는 프레임 차, 임계치 이진화, 연결영역분석, 영역합병과정을 거쳐 인식을 한다. 또한 영상에서 매 프레임이 진행될 때 지하철의 유무(off, on)와 진출입(in, out)으로 나누어 판단할 수 있다. 실험 결과로서 선로상에 진입하는 지하철의 영상은 모두 인지, 판별하였으며, 진출입유무도 5프레임 차를 이용하여 모두 정확하게 판별하였다. 본 연구는 차후 이루어질 지하철 선로상의 낙하하는 물체를 인지하기 위한 필수적인 기법으로 사용할 수 있다.

• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.1-5
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• 1999

Based on the development of designed technology for aluminum carbody. the prototype aluminum carbody has been constructed. All extrusion profiles required for the carbody has been produced and their quality has also been proven. For sound construction. welding technology to join aluminum extrusion profiles has been developed and jigs for precise assembly of blocks have been made. The aluminum carbody for urban subway train has been completed with the required chamber being set and the welding deformations being constrained by jigs. The safety of the carbody structure has also been proven by the static load test. And also, painting technology has been developed and the surface of the carbody has been pre-treated and painted. The developed technology to construct the aluminum carbody can be used in mass production of aluminum cars ordered by domestic and foreign customers.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.501-506
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• 2004

This paper aims to suggest the feasibility of rapid operation scheme generated in preceding study, 'A study on development of operation planning for rapid service in urban railway(An introduction)' through application it to present subway lines in Seoul Metropolitan area. In case of line 3, without the Passing Track 'Turning train outstrip mode' is the best policy. In case of line 4, with the Passing Trank 'Passing track mode' may be the best way to realize the this scheme. Also, there is feasibility in the line 1, line 5, line 6, line 7 but there is no possibility it is applied to line 2 and line 8. In conclusion, this paper is intend to suggest the possibility of rapid operation in urban railway by presenting real operation scheme, time tables and amount of power usage and the number of composing trains and variety of demand,

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.9
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• pp.478-484
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• 2006

The paper presents methods of determining the capacity and installation positions of regenerative inverters installed in DC 1500V electric railway system. We suggested a method that approximates using parameters related to substations where regenerative inverters are installed, railway lines and operating motor cars, and another that calculates using regenerative power obtained from Train performance Simulation (TPS) and Power Flow Simulation (PFS). We carried out TPS and PFS for Seoul Subway Line $5{\sim}8$, calculating regenerative power and determining substations where regenerative inverters would be installed and the optimal capacity and number of inverters to be installed.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.182-187
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• 2005

Air spring system was widely accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestically developed productions are shown in good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.722-725
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• 2005

Recently, ground-borne noise and vibration generated by underground transit system has been recognized as an important environmental problem. This study reviews several of the improved procedures that have been used to predict ground-borne vibration. At first, ground stiffness profile is examined by SASW test which is the most reasonable surface wave test. It is very important to acquire the exact ground stiffness profile at ground response analysis. At second, the train loading to act roadbed is calculated by using the real measured phase angle data. In finite element analysis, averaged acceleration method, infinite element, Rayleigh damping and 2-dimensional wave propagation analysis is performed.