• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.44-49
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• 2014

As expansion and contraction of bike disk brake are happened continuously by temperature at repeated urgent braking. In this study, 3 kinds of model are designed according to configurations of holes and thermal durabilities on bike disk brake are investigated by comparing 3 models through temperature and thermal analyses. Maximum thermal stress happened at the disk contacted with pad and the connection part fixing disk rotor. Instead of initial state, the temperature is uniformly distributed at transient state. As the area of hole at disk rotor face becomes wider, thermal stress becomes lower at the initial state. On the other hand, in case the number of holes increases, thermal stress becomes lower at the elapsed time of 100 seconds. The thermal durability of bike disk brake can be improved by applying this study result with configurations of holes.

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.336-336
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• 2005

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.164-172
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• 2000

To follow a moving target keeping a certain distance it is essential for a mobile robot to detect the target first and to measure its pose and velocity. This paper proposes a new solution for this problem using the accumulated ultrasonic image which is constructed by accumulating the returned ultrasonic signal along the time axis for a certain number of measurement periods. A moving target is separated by selecting the trajectory whose inclination is different from others in the imag since the inclination of a trajectory represents the relative speed of the target against the mobile robot. The proposed algorithm was implemented on a mobile robot and has shown that the robot follows a moving target successfully.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.754-755
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• 2011

본 논문은 발전기보호를 위한 전압억제 과전류계전기에 관한 것이다. 발전기 후비보호를 담당하는 전압억제 과전류 계전기능은 발전기 전부하전류의 150~200[%]의 범위내 과부하상태에서 불필요하게 Trip 되는 것을 방지하는 역할을 한다. 본 논문은 대형 발전기 내부사고 보호를 위한 다기능 IED 시제품 기술 개발 과제의 1차년도 진도보고의 일부로서 0사의 DGP를 Target 계전기로 삼아 연구를 수행하였다. 본 논문에서는 전압억제 과전류의 동작특성과 특성방정식계전기, 정정기준 분석 및 제시안, 논리를 알아본 후 최종적으로 알고리즘을 정립하였다.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.395-398
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• 2003

This study presents wrong hand calculations for fault analysis at field on the real AC railway system. Hence, we correctly revised the hand calculations. We propose AC railway system model by using EMTDC. Fault studies are performed. We also compare revised hand calculations with EMTDC simulation to verify the proposed model made by EMTDC. So, we can confirm that the model made by using EMTDC is correctly designed.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.405-408
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• 2003

국내철도는 많은 철도선로를 전철화하고 있다. 25kV-60Hz 전철화구간에서 운행하는 전기차량으로 인하여 고조파에 대한 문제가 있다 이를 해결하기 위하여 AT급전방식에서의 고조파 특성을 해석하고 차량에서 발생하여 변전소로 유입되는 고조파를 저감시키기 위한 대책설비가 필요하다 여기에서는 지금까지 고조파 해석에 사용된 3종류의 고조파 해석모델과 기존선 전철화 과정에서 고조파 대책설비 설계에 대한 3가지 예를 보인다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.203-205
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• 2008

전기철도의 에너지 소비형태를 다른 수송기관과 비교해 보면 에너지 소비 분담을 측면에서 약 8% 정도를 차지하고 있으나, 수송 분담율은 약 30%이상을 점유하고 있으며, 화물의 경우 수송량의 5%를 담당하고 있지만 에너지 소비는 약 1%미만으로 에너지 효율성이 높은 것으로 나타났다. 그러나 기존의 방법으로 에너지 소비에 대한 효율성을 비교 하는 것은 에너지 소비원이 다르기 때문에 문제가 있어 본 연구에서는 원유로부터 환산하는 효율 계산방법과 필요 에너지, 유효에너지 즉, 'exergie'에 의한 평가 방법을 제안하였다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.250-252
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• 2008

DC traction system generates leakage current because running rails are used in return circuit. And it is very important to estimate the leakage current to the train operation situation. Therefore this paper presents dynamic simulation technique that is very similar to the real operation situation using TPS and PSCAD/EMTDC. For this we model DC traction system included in DC substation, variable feeding circuit model and variable train model. And we extract train location and power using TPS program and use these data for dynamic simulation. Finally we can estimate leakage current to the various operation condition using dynamic simulation.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.264-266
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• 2008

DC transit system has been adopted in the metropolitan area, Korea since 1974. EMU in this system always reiterates that acceleration and retardation. When EMU decelerates using electric breaking, regenerative power occurs. Regenerative power can be consumed in vicinity EMU on the same line or in resistor. If DC transit system has inverter for reusing regenerative power, Energy efficiency in DC transit system will be increased. This paper present a scheme to set up the starting voltage for the developed inverter and its field test result.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.472-475
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• 2008

A DC distributed power system(DPS) has many loads with varied functions. In particular, there may be large pulsed toads with short duty ratio, which can affect the normal operation of other loads. In this paper, a bi-directional converts with inductive storage is used as a DC bus conditioner to damp voltage transients on the bus. In addition, the constant frequency hysteresis control technique for a DC bus conditioner is presented. A simple and fast prediction of the hysteresis band-width is implemented by the phase-lock loop control, keeping constant switching frequency. This technique offers the excellent dynamic response in load or parameter variation. The control performance is illustrated by simulated results with the SABER package. The proposed hysteresis control results in the shortest and the smallest excursions.