• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.21-27
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• 2002

In this paper, a simple test rig of high-speed crash for the front members of vehicles was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the traction wire and by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. In order to measure the energy absorbed by the specimen when it collapse to the wall and during it deform, the two strain gage type load cells are used at the wall place. The test rig rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.

• 비파괴검사학회지
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• 제32권6호
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• pp.696-702
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• 2012

In this study, a noncontact laser ultrasonic system is proposed for rail defect detection. An Nd-Yag pulse laser is used for generation of ultrasonic waves, and the corresponding ultrasonic responses are measured by a laser Doppler vibrometer. For the detection of rail surface damages, the shape of the excitation laser beam is transformed into a line. On the other hand, a point source laser beam is used for the inspection of defects inside a rail head. Then, the interactions of propagating ultrasonic waves with defects are examined using actual rail specimens. Amplitude attenuation was mainly observed for a surface crack, and reflections were most noticeable from an internal damage. Finally, opportunities and challenges associated with real-time rail inspection from a high-speed train are discussed.

• 한국철도학회논문집
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• 제13권6호
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• pp.577-582
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• 2010

고속철도 운행에 따라 레일표면결함에 대한 관리의 중요성이 점점 더 증대되고 있다. 차량의 고속주행시 레일표면결함은 레일의 피로수명 단축 및 궤도의 열화 촉진, 승차감 저하를 유발하기 때문이다. 현재 경부고속철도에서는 레일의 효율적 유지보수를 위하여 레일연마를 수행하고 있다. 본 논문에서는 레일연마에 따른 레일의 피로수명을 예측하였다. 이를 위해서 연마 후 KTX 운행시 레일 저부의 휨응력을 계측하였으며, Rain-flow counting 기법을 적용하여 빈도해석을 실시하여 RCM에 의해 등가응력범위를 산정하였다. 선형누적피로피해를 이용한 피로수명 평가방법은 수정 Miner 법칙에 기초하였다. 해석결과 연마에 따른 레일의 피로수명이 15% 증가되는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제15권4호
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• pp.2511-2518
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• 2014

레일 매립형 궤도시스템은 연속레일지지방식으로 하중분산 효과가 크며, 궤도부재에 발생하는 응력이 매우 작다. 다양한 장점을 갖고 있는 레일 매립형 궤도는 국내에 적용사례가 드물며, 고속 운행선 적용을 위한 연구는 매우 미흡하다. 본 논문에서는 고속운행선에서의 레일 매립형 궤도시스템 적용을 위한 기초연구로써, 실내시험을 통한 수직강성을 도출하였으며, 도출된 강성과 이론해석을 통해 최적단면을 도출하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1173-1177
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• 2004

The high investment is necessary for the new high speed lines. So the KRRI was interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The tilting train system has been developed because the reconstruction of railway for the cant compensation costs very high. The purpose of the tilting system is to compensate the centrifugal acceleration in order to reduce the lateral acceleration of the passenger at high speed on the curves.The pantograph of the tilting train is indispensable in order to supply the electrification equipments with power in safe. The dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force and the contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the active control of pantograph and presents the LQ-servo controller to reduce the contact force variation.

• 한국철도학회논문집
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• 제12권5호
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• pp.670-677
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• 2009

본 논문은 최고속도 400km/h의 차세대고속열차 차상신호장치의 최고속도시험을 위한 방안을 연구한다. 차세대고속열차 차상신호장치는 열차가 고속선 자동열차제어(ATC)구간과 기존선 자동열차정지(ATS) 및 자동열차방호(ATP)구간을 운행하는 동안 기관사에게 운전정보를 제공하고 기관사실수, 신호장치고장, 천재지변 등으로부터의 열차 안전 확보를 목적으로 한다. 차세대고속열차 최고속도 400km/h 시험은 차상신호장치를 포함한 열차성능 검증을 위한 필수과정으로써, 본 논문에서는 차상신호장치의 기능 및 최고속도시험의 필요성을 분석하고, 고속선 ATC구간에서 최고속도시험을 실시하기 위한 인프라의 변경사항 및 구체적인 시험방안을 연구한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.12-15
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• 2005

In April 1, 2004, age of high-speed railway was opened to korea railroad. The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail farce, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, examined speed elevation possibility use the korean style high speed railway vehicle for reduce the running time of high-speed railway between high speed line and conventional line.

• 대한토목학회논문집
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• 제34권4호
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• pp.1261-1267
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• 2014

철도노선은 도로노선과 달리 운행비용, 특히 에너지비용이 전체 생애주기 비용에서 차지하는 비중이 높은 것으로 알려져 있다. 본 연구에서는 경부고속철도의 사례를 중심으로 철도 노반건설비와 에너지비용의 상대적 비중을 분석하였다. 이는 최근 활발하게 연구가 이루어지고 있는 전산화된 철도선형 최적화가 단순히 건설비 최소화만을 목적으로 할 수 없으며, 에너지 비용을 포함한 전반적인 생애주기 비용의 최소화를 목표로 하여야 함을 의미한다. 경부고속철도 운행실적이 아직 10년에 불과하기 때문에 향후 20년간의 운영 시나리오를 다양하게 설정하여 분석한 결과, 에너지비용이 건설비용의 10~30% 수준으로 나타났으며, 이는 일반적으로 알려진 비중보다 낮은 수치이다. 철도 선형 최적화를 위한 방법론 정립에 있어 에너지 비용을 고려할 경우, 그 상대적 비중을 고려할 수 있는 방안을 제시한데 본 연구의 의미가 있을 것이다.

• 전기학회논문지
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• 제66권9호
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• pp.1431-1436
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• 2017

The high-speed railway of catenary system, supplies a stable electric power supply to the train by satisfying the special conditions between pantograph and trolley wire, which operates more than 250km/h mutually sliding and feeding electric lines. According to Korean Railway Standard KRS PW 0026-13 (R), the standard for the grip strength of the dropper clamp in conventional line is established, but the high-speed railway line is not yet. When the grip strength of the dropper clamp is detached from the catenary line of the high-speed railway line, various problems may occur, such as damage to the pantograph due to the collision and arcing. In this paper, it is expected to be used as a basic data for establishing the durability criteria of the high-speed railway dropper clamp by verifying the dropper clamp on the Gyeong-bu and Honam high-speed line.

• Journal of Mechanical Science and Technology
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• 제20권4호
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• pp.482-493
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• 2006

The carbody structure of a high speed train passing through a tunnel is subjected to pressure fluctuation. Fatigue strength of the carbody structure against the fluctuating pressure loading should be proved in the design stage for safety. In this study, to get the useful information on the pressure fluctuation in the tunnel, measurement has been conducted during test running of KHST on the high speed line for two years. The measured results were analyzed and arranged to be used for carbody design. A prediction method for the magnitude and frequency of pressure change was proposed and the propagating characteristics of pressure wave was investigated. By statistical analysis for the measured results, a pressure loading spectrum for the high speed train was given. The proposed method can also be used to estimate the pressure loading spectrum for new high speed line at design stage combined with the results of train performance simulation.