• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.19-27
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• 2014

Urban railway vehicles operate in downtown areas. Due to increases in the number of passengers and changes in the service plans, railway vehicles are expected to operate on sharp curved tracks. However, on these tracks, the running stability of the railway vehicles is significantly decreased and the creepage is increased. Creepage causes the wheel/rail to wear and vibration. Therefore, reducing the creepage helps ensure the running stability and can be beneficial for the environment and cost. In this paper, the longitudinal creepage is analyzed using a railway vehicle model on a sharp curved track. Furthermore, in order to minimize the problems when a railway vehicle runs on a sharp curved track, the characteristics of a bogie are optimized using response optimization.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.541-545
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• 2010

Because contemporary rolling stock system is complex and highly advanced, and it builds mutual interface, it is necessary to manage maintenance of rolling stock systematically. This study present a case, which shows how to adopt and apply RTD(Remote Transmission Device) integrated to train information collection device. After the train service is complete and the train enters the main subway station, various kinds of information collected from TCMS(Train Control Monitoring System) is transmitted to train depot information collection device through RTD. This study suggests that RTD integrated to train information collection device helps build an effective rolling stock maintenance system by improving reliability of data transmission and cutting maintenance costs.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.115-121
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• 2009

Maglev guideway is expected to be a new public transportation for future because of its environmental and special characteristics. Recently, Korean government initiated an urban maglev project to build a commercial line in Incheon International Airport by year 2012. For practical use of UTM02, it is essential not only to verify the performances of the vehicle but also to formulate the design rules of Maglev Guideway. In this paper, maglev guideway is analyzed by Finite Element Method and then obtained dynamic characteristics such as displacements, acceleration and impact factor.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.772-774
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• 2012

최근 차량과 플랫폼 사이의 공간에 휠체어의 바퀴 또는 승객의 발이 빠지는 등의 안전사고가 보고되고 있어 교통약자의 이동을 제한하는 요소로 작용함에 따라 차량과 플랫폼 사이 공간을 메우는 안전스텝을 개발하게 되었다. 안전스텝으로 기존 플랫폼에 설치하는 고무타입은 고정식 고무발판을 미리 설치해 두어 차량과 플랫폼의 간격을 미리 줄이는 방식이나 직선, 곡선 형태의 각각의 역사가 가지는 조건에 유연하게 대응하고, 차량의 승객수와 플랫폼의 조건에 따라 달라지는 승하차 높이에 유연하게 대응하고자 차량에 설치하는 방식을 개발하게 되었다. 본 논문에서는 개발한 안전스텝의 구성 및 기능을 설명하고 논하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.545-551
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• 2016

In this study, we evaluate the braking performance of an urban railway vehicle to verify its basic safety condition. The braking performance evaluation methods, deceleration measurement and braked weight percentage, were compared for trains with different numbers of cars, in order to assess the advantages of each method and their compatibility. With a probabilistic braking model, the effect of the adhesion coefficient distribution was analyzed in accordance with the train composition. A train with many cars has a narrower deceleration distribution width than one with few cars. The braked weight percentage method is expected to be useful in the design of train signal systems, because it allows the braking distance to be calculated for various initial brake velocities. The deceleration distribution model and its results are expected to be useful as a basis for precise train signal design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.605-616
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• 2014

The purpose of this study is to analyze transport efficiency of each of the 17 urban railway lines being operated by national public agencies using Data Envelopment Analysis (DEA) and to seek strategies for improving efficiency of the urban railway system. The study identified the economies of scale derived from these values of efficiency and examined the effects on cost for free ride loss and profit of transport by the fare system as the external factor. At the time, Transport profits are estimated by two production factors such as the number of vehicles and service frequency derived from multiple regression. Finally, the measures to improve the efficiency were presented in terms of profitability in the national urban railway line by applying the values of efficiency derived from DEA to multidimensional scaling (MDS).

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.118-122
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• 2010

The study presents a standard time-temperature curve to evaluate the fire performance of subway tunnel structures. The central subway section is 135km long in Korea, the fourth longest in the world. The number of subway tunnels has been increasing rapidly and fire risk is proportional to the tunnel length. However, an adequate time-temperature curve for subway tunnel fires does not exist. Therefore, we studied a proposed foreign fire design model for which the heat rate is based on the traffic, and we present an appropriate time-temperature curve for Korean subway tunnels. The ISO 834 curve was used as a fire design model and the temperature distribution in the tunnel was estimated using numerical analysis. This led to a proposal for effective measures against subway tunnel fires.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.27-36
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• 2010

Recently, the management of metro business in large cities has become more difficult because of increased construction and operation costs. The purpose of this paper presents the construction of transfer system to resolve about recent tendency to decrease of metro-users and diminution of use efficiency which are serious problems of Busan metro. To cope with this situation, it is necessary to examine the methods of obtaining returns on development profits of land value rises that occur due to transfer system construction between Busan metro line #1 and line #2 in Yangsan area. Therefore, it was made use of research on metro utilization to presuppose service improvement, as an alternative, in the transfer system construction between metro and metro which might be powerful influence over metro-users. In this research, it was examined the actual situation of rises in land values brought about by the transfer system construction of metro line #1 and line #2 in Yangsan area with application of four (4) methods, and have calculated a basis of the development profits produced by the transfer system construction of metro line. According to the economical efficiency analysis, the total construction cost amount to 4,827.1 billion won of case #1 based on single track, and evaluate economically as B/C to 1.013, NPV to 72.7 billion, IRR to 5.614 percent.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.417-418
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• 2020

효율 및 내환경성에서 우수한 성능을 갖는 매입형 영구자석 동기전동기(IPMSM, Interior Permanent Magnet Synchronous Motor)는 최근 철도차량용 견인전동기로서 주목받고 있다. 일반 도시 철도차량의 추진제어시스템은 장시간 연속 운행 및 자연통풍냉각 방식의 설계가 요구되므로 대전력 스위칭으로 인한 발열 문제가 고려된 낮은 스위칭 주파수 및 6-스텝 제어 아래 인버터의 고성능 제어가 필요하다. 따라서 본 논문에서는 6-스텝 및 낮은 스위칭 주파수로 IPMSM을 제어하기 위한 PWM(Pulse Width Modulation) 동기화 방법을 기술하고 시뮬레이션을 통하여 제어 성능을 검증하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.111-112
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• 2007