• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권12호
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• pp.709-714
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• 1999

This paper is focused on the adhesion control method to improve traction efficiency using the estimated adhesion for railway propulsion system. Recently, the wheel slippery is frequently occurred due to light weight of train and power increasement of traction parts. This phenomenon occurs a traction loss and a poor ride comport. Therefore, the adhesion control which is able to prevent the slippery and to control the traction on a maximum adhesion is absolutely needed. This paper introduces typical methods for adhesion control and proposes two novel adhesion methods using the estimated adhesion.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.329-334
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• 2010

Purpose: Adhesion after flexor tendon injury is a result of fibrosis between tendon and tendon sheath. This, finally interfere with gliding mechanism of tendon and results in functional problem of hands. Therefore, there have been many trials to reduce adhesion around the tendon. However, there is no standard procedure clinically practiced in hospitals. Mitomycin-C is an antineoplastic alkylating agent that decrease fibroblast proliferation and scar formation. It is commonly used in many surgery to reduce postoperative adhesion. This study was designed to observe the effect of Mitomycin-C on preventing adhesion in injured flexor tendon. Methods: The deep flexor tendon of digit 2 and 4 in the left forepaw of 15 New Zealand White rabbits were subjected to partial tenotomy. In study group, injury site was exposed to a single 5-minute application of Mitomycin-C, and in control group was left untreated. Digit 2 and 4 in the right forepaw of each rabbit were considered as nonadhesion control group. After 2 weeks, the animals were sacrificed and digits were amputated for biomechanical test and histological study. Results: In biomechanical study to measure yield point, mean yield point of non-adhesion control was $17.43{\pm}2.33$ and $25.07{\pm}4.03$ for adhesion control, which proves increase of adhesion in adhesion control group (p<0.05) in 95% confidence. In Mitomycin-C group, mean yield point was $12.71{\pm}4.97$. Compared with adhesion control, there was decrease in adhesiveness in Mitomycin-C group (p<0.05) in 95% confidence. In histological study, the result of adhesion control revealed massive adhesions of bony structure, fibrotic tissue and tendon structure with ablation of the border. However in Mitomycin-C group, we could find increased fibrotic tissue, but adhesion is much lesser than adhesion group and borders between structures remain intact. Conclusion: This study suggests that Mitomycin-C can significantly reduce adhesion of injured flexor tendon in rabbit model.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권1호
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• pp.40-47
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• 2002

This paper describes a re-adhesion control method for the Korean High-Speed Train (KHST) with parallel induction motor drive. To keep a traction efficiency and to improve vehicle maintenance, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion controller is designed as the subsystem of induction motor vector control. In order to verify performance of the proposed control techniques, the simulation is executed by train model and a downscaled re-adhesion control simulator is utilized. Both simulation and running test results show that good re-adhesion characteristics are obtained.

• 한국산학기술학회논문지
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• 제7권2호
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• pp.150-156
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• 2006

전기철도차량의 성능특성을 향상시키기 위한 효과적인 방법중의 하나는 바퀴와 레일사이의 점착성능을 향상시키는 것이다. 점착특성을 연구하기 위해서 실제 차량을 등가 모델링한 점착시스템을 제작하였다. 이 시스템은 다양한 점착 파라미터를 변화시켜 바퀴와 레일사이의 점착력을 바꿀 수 있도록 제작되었다. 이 논문은 공전속도를 제어하는 기능을 추가하여 점착성능을 향상시키는 연구이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1455-1460
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• 2004

In electric motor coaches, when the adhesion force coefficient between rail and driving wheel decreases suddenly, the electric motor coach has slip phenomena. The characteristics of adhesion force coefficient is strongly affected by the conditions between rails and driving wheels, such as moisture, dust, and oil on the rails and so on. This paper proposes the vector control structure for the improved re-adhesion control with paralleled control of induction motors under the sudden variation of the adhesion force coefficient.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2423-2425
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient(AFC) according to slip velocity. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the re-adhesion control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. fuzzy logic controller(FLC) is petty useful with slip through that compare fuzzy with PI control for the controller performance. These procedure is implemented using a Pioneer 2-DXE parameter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.50-52
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient according to slip velocity. In oder to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the anti-slip control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. These procedure is implemented using a Pioneer 2-DXE parameter.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권1호
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• pp.32-39
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• 2000

In this paper, an improved re-adhesion control scheme is proposed for 1C4M railway traction system. It is well known that the coefficient of adhesion between wheel and rail has a maximum value at a certain slip velocity. In the proposed scheme, adhesive effort is estimated by a full-order observer and the driving torque of motor is controlled to get maximum adhesive effort. The-adhesion control simulator is designed to verify the proposed re-adhesion control algorithm. The simulation results and experimental results are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.334-340
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• 2002

This paper proposes a new anti-slip re-adhesion control system fur electric railway vehicle driven by inverter-fed induction motors. This paper introduces an instantaneous tangential farce coefficient estimator between driving wheel and rail, which is based on disturbance observer. The torque command of proposed system regulates to exceed this estimated tangential farce coefficient in order to avoid undesirable slip phenomenon of driving wheels. We have already proposed the anti-slip re-adhesion control system based on disturbance observer for simplified one wheel equivalent model successfully. This paper extend to this system to the actual bogie system, which has four driving wheels driven by two induction motors fed by one inverter. In order to apply anti-slip re-adhesion control to the actual bogie system a new anti-slip re-adhesion control based on both disturbance observer and speed sensor-less vector control of induction motor with quick response are combined. The experimental results and the numerical simulation results prove the validity of the proposed control system.

• 전력전자학회논문지
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• 제6권3호
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• pp.299-306
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• 2001

전기철도차량의 성능특성을 향상시키기 위한 효과적인 방법중의 하나는 바퀴와 레일사이의 점착성능을 향상시키는 것이다. 점착특성을 연구하기 위해서 실제 차량을 등가 모델링한 점착시스템을 제작하였다. 이 시스템은 다양한 점착 파라미터를 변화시켜 바퀴와 레일사이의 점착력을 바꿀 수 있도록 제작되었다. 이 논문은 공전속도에 의한 토오크제어 방법으로써 공전속도의 진동을 억제하기 위한 연구이다.