• Journal of Welding and Joining
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• v.17 no.3
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• pp.26-35
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• 1999

On the laser weld production line, a slight alteration of the welding condition changes the bead size and the strength of the weldment. The measurement system is produced by using three photo-diodes for detection of the plasma and spatter signal in $CO_2$ laser welding. The relationship between the sensor signals of plasma or spatter and the bead shape, and the mechanism of the plasma and spatter were analyzed for the bead size estimation. The penetration depth and the bead width were estimated using the multiple regression analysis.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.2
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• pp.144-153
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• 1991

This paper presents an algorithm to improve accuracy and reliability in the state estimation of contaminated bad data. The conventional algorithms for detection of bad data have the problems of excessive memory requirements and long computation time. In order to overcome these problems, a measurement compensation approach is proposed to reduce computation time, and the partitioned measurement error model has the advantage of remarkable reduction in computation time and memory requirements in estimated error computation. The proposed algorithm has been tested for IEEE sample systems, which shows its applicability to on-line power systems.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.388-390
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• 1995

A new control scheme based on dead beat control with adaptive parameter estimation for PWM Inverter is proposed. The proposed scheme updates dead beat control parameters continouously, and make PWM inverter excellent performance at any load or parameter condition. Simulation results show very attractive features in this proposed scheme.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.25-27
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• 2003

In this paper the instantaneous thrust of a linear induction motor(LIM) with cage-type secondary is estimated by the line voltages and phase currents measurement when the LIM is fed by PWM inverter. The estimated thrust values according to various input frequencies are compared with the measured ones.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.164-167
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• 1996

This paper presents an off-line P.I.D parameter estimation method during normal operation in power plant. The process parameters are estimated using the recursive least square method. The controller parameters are estimated on the basis of desired characteristics of the dynamic model of the closed-loop control.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.545-550
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• 2009

A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1849-1854
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• 2010

Energy Storage System(ESS) is installed at feeding line of railway substation. ESS will absorb regenerative energy when train braking and also charge electric energy when feeding line is no load condition. Absorbed and charged energy will be supplied when train is accelerating condition. Due to ESS the energy variation will be minimized and this effect is estimated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.371-376
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• 1994

This paper presents an on-line modeling method approach for the machine condition. the machine condition is continuously monitored with a sensor such as, a vibration, a current, an acoustic emission (AE) sensor. In this study, neural network modeling by radial basis function is designed for analysis a prediction error. An on-line learning algorithm is designed using the RLS(recursive least square) estimation and the existing clustering method of Kohonen neural network. Experimental results show that the proposed RBNN modeling is suitable for predicting simulated data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.89-93
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• 2005

인버터 구동 회전기기의 운전수명을 보장하기 위해서는 기존의 시험 방법에 포함되지 않은 PWM 가변속 구동에 따른 고조파 손실과 과도전압 충격의 문제점을 고려한 새로운 장기 신뢰성 평가 기법이 절실히 필요한 상황이기 때문에 본 연구에서 시험모델을 설정하고자 한다. 결과로는 종래는 비파괴시험에 의한 off-line 진단법이 주로 시행되었지만, 최근에는 상태량을 계측하는 신종 센서의 개발이 진행되어 모니터링법에 의한 on-line 진단법이 점차로 증가하고 있다.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1238-1240
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• 1998

For economic operating of distribution system, utility has to minimize the loss in distribution line by controlling reactive power and power factor. This paper presents calculation of reactive power in distribution line, estimation of the condenser capacity according to distance, and computation of optimal location and proper condenser capacity.