• Proceedings of the KSR Conference
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• 2002.10b
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• pp.845-850
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• 2002

Maglev is the vehicle which can run in levitated condition by the electro-magnets, and the vehicle can run without any contact condition. The vehicle is devided in two parts such as carbody and bogies, and the bogies are the driving device of the vehicle. There are many equipments in the bogie, and the frame endure many loads occurred in the operation of the vehicle. The bogie frame is designed and manufactured in the view of good safety and maintainability, and the engineers work to accomplish this purpose.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.439-443
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• 2003

MAGLEV is the vehicle which can run in levitated condition by the electro-magnets, and the vehicle can run without any contact condition. In MAGLEV system achieving a high magnetic field for minimum weight is a noteworthy goal. Unfortunately the two aspects of this goal high field and low weight are contradictory. Suitable designs must be sought using optimization techniques. In this paper is a technique for designing a electro-magnet in terms of simple equation.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1028-1032
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• 2005

Due to excessive city's Traffic jam, which an energy and pollution problem of metropolis have risen seriouly, Many industrialized countries have developed many kind of new transportation system for the purpose of substituting the mass traffic. Maglev system has began the revenue operation from Japan and China recently and it is beginning highlighted the new system. We examined specification to be improved in the system and safety of maglev.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.628-633
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• 2003

Recently, the electronic circuit with microprocessor based control system instead of conventional analog circuit is widely used for rolling stock, and also these circuits are widely adopted for train control and monitoring in modem rapid transit system. Noise, distortion and attenuation are always present in electronic equipments and strictly limit performance. The purpose of this paper is to propose noise reduction technology for electronic equipments in rolling stock.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.305-308
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• 2002

패턴 인식(Patterns Recognition)은 인공 지능의 한 분야로서 이해할 수 있는데, 요즈음은 보안과 관련하여 많은 연구가 진행되고 있다. 웨이블렛 변환(Wavelet Transform)은 공간-주파수 영역에서 신호의 국소화를 효율적으로 구현할 수 있다. 하지만, 이를 패턴 인식의 특징 추출에 그대로 이용할 경우 입력 신호의 위치 이동 등이 문제가 되며, 이것은 또한 에러 요인이 된다. 본 논문에서는 웨이블렛 변환을 패턴 인식에 적용할 경우 발생하는 입력 신호의 위치이동에 따른 문제점을 보완하여, 개선된 방법으로 패턴 인식에 사용할 수 있는 알고리즘을 제안하며, 실험 결과를 바탕으로 그의 타당성을 보인다.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.35-42
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• 2011

Recently, the Next Generation High Speed Train(hereinafter HEMU-400X) which has been developing is the power distribution type high speed train. The power is on every each car and all bogies are installed on the front and rear of every car comparison with KTX and KTX-Sancheon which are consist of power cars and linkable bogies. HEMU-400X can be designed much more seats than others because there are not power car separately. However, that type has no advantage for vibration and noise due to distributed power and more faster design speed. Therefore, in this study, the design of floor construction for preventing the vibration from under the floor is considered.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.842-848
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• 2011

The low-floor tram is a kind of railway vehicles which is operated on the street way track. For reducing the radius of curvature of the track, the tram consists of some carbody modules, and the articulation systems connect and support these carbody modules. The kind of articulation systems would be the hinge type and the pitching type. The hinge type articulation could allow only the yawing motion of the carbody modules, and the pitching type articulation could allow the pitching and yawing motions of the carbody modules simultaneously. With these function of the articulation systems, the tram could be operated on the horizontal and vertical curvature of the track. The number of each type of articulation could be decided with the number of carbody modules, and the manufacturer would decided the position of each type of the articulation in the view of the stability of carbody modules in the operation condition.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.235-238
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• 2004

유류 오염토양에 대한 과산화수소의 화학적 고도산화에 대한 실험실 및 현장 적용 가능성을 타진하였다. 현장 오염토양 10g에 각각 과산화수소(34.5%) 원액을 중량비로 0.3%, 0.6%, 1.0%, 2.0%를 처리하여 혼합 후 실험실에서 1일 반응 후 TPH 농도를 분석하였다. 분석결과 토양 대비 2.0%의 과산화수소를 투입한 처리구에서 가장 높은 복원 효율을 측정할 수 있었고 2.0%까지의 투입농도에서 미생물의 농도 변화는 측정되지 않았다. 오염된 토양에 과산화수소를 오염 토양 중량 대비 2%를 분무기로 살포 후 로타리가 설치된 경작 장비로 뒤집기 수행하여 1일 후 오염토양의 오염농도를 분석한 결과 초기 TPH 5,365ppm의 농도가 2,317ppm으로 56.8% 복원된 것을 확인할 수 있었다.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.600-604
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• 1991

In this paper, an advanced PWM modulation strategy for driving a variable-speed induction motor is introduced. According to this method, the technique of efficiently eliminating harmonics component is achived. A switching pattern was computed making use of the near-proportionality of voltage and frequency in AC machines operating with constant flux. At low magnitudes and low frequencies of the foundamental, many more harmonics are eliminated than at high magnitudes and frequencies. In order to keep the inverter switching frequency constant over the output frequency range, chopping times diminishes as the frequency of the fundamental increases.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.605-610
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• 1991

In inverter system for driving induction motor, the output harmonics are hamrful in induction motor drive because it leads to ripple torque and induction interference. For electrical drives using PWM(Pulsewidth Modulation) inverters and ac motors, the methods for efficiency optimal control have been developed. In this paper, two different PWM methods for inverter and voltage control technique are described. In order to reduce or minimize losses, various forms of PWM strategy such as, PM (Positive Modulation) and NM (Negative Modulation) are discussed. The results show the feasibility of obtaining practically sinusoidal output waveforms which are highly desirable in most inverter application.