• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.342-347
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• 2003

In this paper, an active vibration control of a translating tensioned string with the use of an electro-hydraulic servo mechanism at the right boundary is investigated. The dynamics of the moving strip is modeled as a string with tension by using Hamilton’s principle for the systems with changing mass. The control objective is to suppress the transverse vibrations of the strip via boundary control. A right boundary control law in the form of current input to the servo valve based upon the Lyapunov’s second method is derived. It is revealed that a time-varying boundary force and a suitable passive damping at the right boundary can successfully suppress the transverse vibrations. The exponential stability of the closed loop system is proved. The effectiveness of the control laws proposed is demonstrated via simulations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.63-71
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• 2014

A single-inverted-pendulum model is presented to simulate and predict the passive response of human balance control. This simplified biomechanical model was comprised of a torsional spring and damper, and a lump mass. An estimation of frequency response function was conducted to parameterize the complexity. The frequency domain identification method is used to identify the parameters of the model. The equivalent viscoelastic parameters of standing body were obtained and there was good conformity between the simulation and experimental result.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1332-1335
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• 1996

It is very important to predict the future position for the heavy vehicle with evasive maneuvering. In this paper, we considered for the manual image tracking system. The vehicle images are received from gyro stabilized mirror system, pass through the optical lens, processed, and displayed on the TV monitor. The operator try to lay the reticle to the center of vehicle image. When the vehicle is moving, the mirror platform (actually the line of sight) should follow the vehicle and the angular rate information is picked up from the mirror stabilized system. This rate signal should be used to predict the future vehicle position. The problem is that the visual system of the human operator is in the closed loop system. The rate signals are disturbed by the operator. In addition, there are some non linearities concerned with the control handle bar and the servo control system. The proposed Kalman filter, combined with some modifications for operator disturbance rejection, improved the predication of the future vehicle position when compared with the conventional passive filter used.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.115-122
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• 1996

A 300MHz PLL including FVC (frequency to voltage converter) is designed and fabricated in 0.8$\mu$m CMOS process. In this design, a FVC and a 2nd - order passive filter are added to the conventional charge-pump PLL to improve the acquisition time. The dual-rijng VCO(voltage controlled oscillator) realized in this paper has a frequency range form 208 to 320MHz. Integrated circuits have been fully tested and analyzed in detail and it is proved that pull-in speed is enhanced with the use fo FVC. In VCO range from 230MHz to 310MHz, experimental results show that realized PLL exhibits 4 times faster pull-in speed than that of conventional PLL.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.903-908
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• 2005

Existing ATC/ATO/TWC system has a ATC(Automatic Train Control) antenna for receiving the speed code, a ATO(Automatic Train Operation) antenna for obtaining the exact distance to go to platform and TWC(Train and Wayside Communication) antenna for communication between on-board and wayside system. This paper proposes the ATO/TWC antenna with tele-powering module, telegram transmitter/receiver module. This antenna communicates with a passive type tag(wayside Precision Stop Marker) for the information of distance from the stop position and a active type tag for the door command and status in the platform.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.8
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• pp.1004-1013
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• 1999

This paper considers the transient stability problem of power system. The power system model is given as interconnected system consisting of many machines which are described by swing equations. We design a transient stability controller using passivity and neural network. The structure of the neural network controller is derived using a filtered error/passivity approach. In general, a neural network cannot be guaranteed to be passive, but the weight tuning algorithm given here do guarantee desirable passivity properties of the neural network and hence of the closed-loop error system. Moreover proposed controller shows good robustness by simulation for uncertainties in parameters, which can not be shown in the speed gradient method proposed by Fradkov[3,7].

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.3
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• pp.139-146
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• 2003

In this paper, the steady-state operating performance analysis for the three-phase squirrel cage rotor self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) in addition to a constant-speed prime mover (CSPM) is presented on the basis of an effective algorithm based on its frequency-domain equivalent circuit. The operating characteristics of the three-phase SEIG coupled by a VSPM and/or a CSPM are evaluated on line processing under the condition of the electrical passive load parameters variations with simple and efficient computation processing procedure in unregulated voltage control loop scheme. A three-phase SEIG prototype setup with a VSPM as well as a CSPM is implemented for the small-scale clean renewable and alternative energy utilizations. The experimental operating characteristic results are illustrated and give good agreements with the simulation ones.

• Journal of Power Electronics
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• v.14 no.4
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• pp.742-753
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• 2014

In this paper, a new continuously and linearly controlled capacitive static VAR compensator is proposed for the automatic power factor correction of inductive single phase loads in 220V 50Hz power system networks. The compensator is constructed of a harmonic-suppressed TCR equipped with a new adaptive current controller. The harmonic-suppressed TCR is a new configuration that includes a thyristor controlled reactor (TCR) shunted by a passive third harmonic filter. In addition, the parallel configuration is connected to an AC source via a series first harmonic filter. The harmonic-suppressed TCR is designed so that negligible harmonic current components are injected into the AC source. The compensator is equipped with a new adaptive closed loop current controller, which responds linearly to reactive current demands. The no load operating losses of this compensator are negligible when compared to its capacitive reactive current rating. The proposed system is validated on PSpice which is very close in terms of performance to real hardware.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.5-7
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• 2005

When 345 kV transmission lines began to be operated in 1976,electrostatic shocks were problems due to high electric field. By reducing the electirc field below 3.5 kV/m, the problems were solved. But recently a transmission line route.is proposed, nearby people strongly object to build the line worrying abour the effect of magnetic field,even though they do not really know the megnetic effect. Some environmentalists insists to reduce to reduce the magnetis field to a few mG near the transmission line. So we have studied the mitigation method to reduce magnetic field by two conductor passive loop.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.419-421
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• 2003

송전선로에서 발생하는 전자계에 대한 관심이 증가함에 따라 이를 저감하는 방법에 대한 연구도 활발하게 진행되고 있다. 본 논문에서는 송전선로에 적용할 수 있는 전자계 저감방법중 하나인 수동루프에 대한 성능을 송전선로의 축소모형 실험을 통해 나타내고 그에 대한 결과를 이론적인 계산 값과 비교하였다. 약 1/20 크기로 축소한 송전선로 모형을 제작한 다음 몇 가지 전압, 전류를 인가하여 선로 주변 전자계를 측정하여 그 결과를 정리하였다.