• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.482-487
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• 2005

In the most current Turn-key bidding and Alternative design, is going to establish maintenance plan along with a economical assessment (VE/LCC assessment etc). Generally, establishment of maintenance plan is based on past experiences that are decided upon sensor position and amount with analytic or mechanical control section. But, it is more reasonable that maintenance plan based on level of significance for Probabilistic Risk, with presuming damage probability assessment of structural fracture scenarios. Therefore, in this study it is considered about the technique that an improved maintenance plan of railroad structures using PRA (Probabilistic Risk Assessment) on the basis of structural reliability theory. For this, in the paper, Preventive maintenance plan based on PRA is suggested with an application example of Pansong-Line (Line number 3) railway in Pusan works that actually executed Turn-key design.

• 조명전기설비학회논문지
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• 제18권4호
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• pp.138-143
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• 2004

본 논문은 고속전철 차량에서부터 변전소까지의 고조파에 대해서 분석하였으며, 수동필터를 이용한 고조파 저감 방법을 제시한다. 고속전철 변전소가 공급하는 열차구간에 있어서 운행 열차의 수에 따라 고조파의 파급 특성을 살펴보았다. 고조파는 변압기 과열과 통신유도장해 등 문제를 일으킬 수 있다. 이러한 고조파에 의한 손상을 줄이기 위하여 본 논문은 고조파 저감방법을 제시하였다. 제안된 방법은 PSCAD/EMTDC 시뮬레이션에 의해 증명되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1177-1183
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• 2005

This paper presents the effects of dynamic response of the railway bridge through the suspension system when the train is moving with uniform speed and non-uniform speed Railway bridges are subjected to dynamic loads generated by the interaction between moving vehicles and the bridge structures. these dynamic loads result in response fluctuation in bridge members. To investigate the real dynamic behavior of the bridge, a number of analytical and experimental investigation should be carried out. This paper, a train/bridge interaction analysis program considerate braking action. New scheme consideration of braking action on the bridge using speed-dependent braking function is presented. This program also used torsional degree of freedom and constraint equation based on geometrical relationship in order to take into consideration three-dimensional eccentricity effect due to the operation on double track through quasi three-dimensional analysis.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권4호
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• pp.272-281
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• 2000

This paper deals with the parallel operation of several numbers of PWM converters for a high speed railway train application. Several considerations are made to reduce the transformer interaction which can cause a current control problem in severe case. Also, in this paper, novel control strategy is proposed to achieve a harmonic free primary-side current control under a light load condition using one current sensor independent of the number of converters. In addition, the modified predictive current controller, which is suitable to a digital current controller with a relatively large sampling period, is used. Finally, to verify the system validity, digital control system with TMS320C44 micro-processor and small scale simulator are made and tested.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.1047-1053
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• 2005

This study explored pattern of train operation between Seoul Cheonan after the introduction of KTX in 2004. Both number of trains and seat capacity per day have increased but maximum number of trains per specific hour hasn't changed much. Demand for train shows that it concentrated in a specific time, so number of trains during the peak hour should be increased. But, it is difficult due to line capacity, so increasing seat capacity per train might be an option. An increase in seat capacity should be considered the characteristics of each train lines.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1077-1082
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• 2004

With increasing the number of tunnel constructions, more reliable analysis methods for tunnel excavation is needed to accomplish technically sound design, and stable and economical constructions. For this purpose, a series of construction procedures, which include excavation and support stages of tunneling, need to be considered. In this study, therefore, rock-support response behavior due to railway tunnel construction has been examined by using analytic methods and numerical calculations. For examining rock-support response behavior, the effects of shotcrete, thickness and time of installation have been considered. Through analytic and numerical calculations, it is shown that support pressure becomes higher with increasing the shotcrete thickness and stiffness, and hence the tunnel deformation tends to be stable. It is also important to notice that there is a significant effect of shotcrete installation time on the tunnel deformation, although no significant change in support pressure is observed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.514-521
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• 2004

A routing is the path that an actual train set follows as it moves from one train to another train in a timetable. The number of routings is equivalent to the number of trainsets required to cover the timetable. The primary factors of rolling stock requirement plan include evaluating the minimum number of routings. This can be formulated as a set partitioning problem and solved using enumeration method or column generation method. In this paper we presents an enumeration algorithm which is useful to implement the enumeration method for the rolling stock requirement plan.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.676-681
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• 2005

The regenerative braked cars are being introduced in DC electric railway for energy saving. There has been a recent tendency for DC traction substation with regenerative inverter to increase in number. This is strongly related to the desire for effective utilization of electric power regenerated by DC electric cars and to the aim ensuring stable operation of regenerative braking system. The regenerative inverters DC power feed back from a generative car into AC power at a substation and supplies it to distribution lines. This paper suggest the result of characteristic analysis and capacity simulation. economical analysis in the regenerative inverter system.

• 한국철도학회논문집
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• 제20권1호
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• pp.85-98
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• 2017

일반적으로 철도궤도 상부노반 흙재료는 연속적인 열차의 동적하중을 받게 되어 증가-감소 단계의 응력을 경험하게 된다. 이와 같이 일정한 주기에 따라 반복적으로 재하되는 축차응력(${\sigma}_d$)과 반복재하회수가 증가하게 되어 발생하는 회복변형률(${\varepsilon}_r$)의 비를 이용, 회복탄성계수($M_R$)을 산정할 수 있다. 현재까지 철도궤도하부구조에 적용할 수 있는 통일된 회복탄성계수 측정 시험법이 제시된 바 없어, 본 연구에서는 철도궤도 하부구조에 적용 가능하며, 구속압, 응력조건 및 반복재하회수 등을 종합적으로 고려할 수 있는 반복삼축압축시험에 의한 잠정 회복탄성계수 측정시험법을 제시하였다. 또한 반복삼축압축시험에 의한 잠정 시험법을 통해 산정된 회복탄성계수($M_R$)와 중형공진주시험을 통해 측정한 전단탄성계수(G)와의 상관성분석을 실시하였다.

• Advances in Computational Design
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• 제2권4호
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• pp.257-271
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• 2017

There are many plain concrete arch bridges in Iran that have been used as railway bridges for more than seventy years. Owe to the fact that these bridges have not been designed seismically, and even may be loaded under high-speed trains, evaluation of fundamental frequencies of the bridges against earthquake and high-speed train vibrations is necessary for considering dynamics effects. To evaluate complex behavior of these bridges, results of field tests are useful. Since it is not possible to perform field tests for all arch bridges, these structures should be simulated correctly by computers for structural assessment. Several parameters are employed to describe the bridges, such as number of spans, length of spans, geometrical and material properties. In this study, results of field tests are used for modal analysis and adapted for 64 three dimensional finite element models with various physical parameters. Computer simulations show length of spans has important effect on fundamental frequencies of plain concrete arch bridge and modal deformations of bridges is in longitudinal and transverse directions. Also, these results demonstrate that fundamental frequencies of bridges decrease after increasing span length and number of spans. Plus, some relations based in the number of spans (n) and span length (l) are proposed for calculation of fundamental frequencies of plain concrete arch bridge.