• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2054-2055
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• 2007

이 논문에서는 철도전력시스템에서의 유지보수를 위한 고장률 분석에 관하여 설명하고 있다. 유지보수와 관련된 문제들은 시스템의 다른 부분과도 연관이 있어 기계적 사고의 위험성을 증가시킨다. 그러므로 설비는 교체와 예방정비를 겪게 된다. 여기서는 유지보수의 방법을 욕조곡선을 기반으로 정할 것이다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1570-1572
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• 2005

Is changed from ground signal way to Onboard signal way serving speed elevation of railroad worldwide. Therefore, importance of Onboard signal equipment is rising. Onboard signal equipment value of first time construction important. Domestic railroad and city railroad are built without standard current. Therefore, much expense is paid in maintenance and alternate of equipment. Therefore, establish standard for devices of childhood. Therefore, can have curtailment of operational expenses and specialization of skill human strength.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.30-38
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• 1998

Nowadays, the environmental vibration criteria has been severely restricted from the viewpoint of recipient. The vibration created by urban transit systems can be an important source of community discontent, and can have influence on high technology equipments. This has led to a desire of transit system operators to reduce vibration and to minimize community exposure to vibration. Recent research in this area has significantly increased for transit system engineers to reduce vibration. Unlike other material, soil has a complicated characteristic and it is very difficult to prevent vibration from transmitting. Generally, the trench can use to breaking propagation of vibration on passing way but needs much too maintenance. Therefore, the filled materials for trench had successfully developed and the characteristic test for the filled material had conducted during this term. Finally, we had executed analyses of real characteristic through the propagation test of ground vibration.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.93-98
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• 1999

Numerical simulation is conducted to clarify the heat transfer and fluid flow characteristics of brake disk-lining for rolling stock. Multiple rotational reference frame, k-epsilon turbulent model and SIMPLE algorithm based on finite volume method are used to solve the physical disk-lining model. The governing equations are solved by TDMA(TriDiagonal Matrix Algorithm) with line-by-line method and block correction, From the results of simulation, the characteristics of cooling pattern is strongly affected by the grooves in lining. The face lift of lining affects on the temperature distribution of rear surface of lining as well as the front surface of that. Due to the grooves in lining, it will be expected to extend the maintenance life circle of lining.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.179-186
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• 1998

Three phase squirrel cage induction motor is generally adopted as a traction motor to drive high speed trains because of its robustness for surrounding environment and easy maintenance. In the design of traction molar, reduction of weight is very important in order to reduce kinetic energy to accelerate the vehicle. Therefore, in this paper, design variables of a preliminary designed traction motor to minimize its weight is determined using the optimization technique. Before the optimization process, rotor slot number is determined to reduce vibration and noise by the analysis of magnetic force. As a result, a design example to reduce weight by 12% than that of the preliminary designed motor is presented.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.125-131
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• 2008

This research tries to analyze and investigate the effects of the noise reduction test for the sound-absorbing materials installed tentatively on Metro Line 5. Though the noise reduction effects of each sound-absorbing material showed that there was about $2{\sim}5\;dB$ compared with before and after of the tentative installation, it shows that the noise reduction effects are reducing because of the section change condition such as dust absorption and the rail abrasion as time passes after the tentative installation. Also, many difficulties are occurring in the maintenance of the orbit facilities because of the installation of sound-absorbing materials. Though various abroad products for noise reduction are imported like this, the researches for the noise reduction effect increase for this and the improvement direction are being required because of the poor circumstance of the efficiency aspect compared to the economic investment effect because those are not suited to the character of domestic Metro.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.982-984
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• 2008

Generally, the soil around railroad is contaminated by the leakage of oil during its maintenance or the operation of rolling stock. Because the railroad soil is located under ballast and is hardened with the designated strength due to safety, the characteristics of the polluted site are different. In this study, the phenomena of oil diffusion in the railroad site was investigated using 2-D reactor. The used oil was lubricant. As a result, the maximum diffusion depth of lubricant was about 9.5 cm due to its high viscosity and the hardened soil. The lubricant was diffused by gravity more than by horizontal migration. In the future, these results can be applied to develop a remediation method for the contaminated railroad soil.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2192-2204
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• 2011

Recently, The government is actively transit road-oriented Traffic System to the eco-friendly and high-efficiency railroad-oriented transportation system for the sustainable green growth. The second plan of Nationwide Railway Network which has been officially announced rearrange to integration, multi-core, open architecture country by the railway network and integrate to the one mega city that rink an important city in one hour 30 minute. But the railroad industry is disadvantageous when it compares with the road industry on the ground that railroad industry peculiarities(a cost-benefit analysis, an environment value, etc) have not reflected in the (preliminary) feasibility study for SOC industry. The government establish Improved methodology of Rail Investment Rating System and improved preliminary feasibility study in railroad project by introduction many content(analysis periods, rate of discount, the benefits of shortening of transit hours, the estimation of traffic accident reduction benefits, investment cost of vehicle substitution and operation and maintenance cost of high speed rail) about the Improved methodology of Rail Investment Rating System. This study is intended to consideration the key content that was included in the Improved methodology of Rail Investment Rating System. In addition, the points to be considered for additional study have been reviewed in this study. We hope we will carry out make a reasonable and objective Rail Investment Rating System and to perform the railway industry of the virtuous cycle such improvement plans are reflected at a hereafter railroad section.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.489-500
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• 1997

The number of railway bridges in Korea reaches to about 3,000. Among them, the ratio of steel bridges is about 47%. Most of the long span railway bridges take the truss type, its number is 15 in Korea. These bridges have more than 30 years service life, it is expected that the damages of cracks and corrosion is going. Therefore, the estimation of fatigue life with random stress is considered as significant subject in maintenance. In this paper, the random stress was measured in bridges and counted the stress cycles using the rainflow counting method So, the stress range frequencies and their equivalent stress are obtained and the amplification factor for the span length, bridge types and traveling speed is assessed by the dynamic testing. From the results, the stress range of the stringer and the lower chord is higher than the other members and the characteristics of the stress histogram is varied to the loading system and the amount of the passing through trains. And the impact effects are depended on the traveling speed as well as the span length.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.785-794
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• 2021

This study investigated the current status of the design and direction of improvement of the sign system of urban railway stations in the Seoul metropolitan area to see how difficult it is for users to use. As a research method, first, a theoretical study on the literature of the urban railway sign system, second, a survey on the current status of the sign design of the Gimpo Goldline in the Seoul metropolitan area, and third, a survey on the actual use of the sign and problems was conducted. As a result of the current status survey, the location sign is in central alignment with the font of the guide sign, and the guidance sign is in front/back alignment according to the location of the entrance and exit. The background of the font is white and the text is dark black to make it look good to the user. On the other hand, guidance sign is written in white color and background color is gray color. Currently, the Gimpo Urban Railway Guidance Sign System is newly produced and installed, but there is a lack of user design and needs design maintenance that can clearly deliver information to users.