• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.383-386
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• 1990

This paper concerns a DC-DC converter using the characteristic of series resonance. Operation principle of the system described by the proposed equation is illustrated. Characteristics of steady state of the system which is essential to system design is evaluated for frequency and pulse width characteristic using dimensionless parameter. The proposed circuit based in constant voltage control uses the Pulse Width Modulation - Time Ratio Control method.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.467-469
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• 2001

This paper presents an efficient location estimation methodology for a partial discharge(PD) source in the power transformer. The methodology previously proposed is not suitable for locating a PD source because the ultrasonic signal with medium attenuated through the inner structure. In general, the propagation characteristic of ultrasonic signal with medium is different. Therefore, using this propagation characteristic, we can detect the location of PD source. In this paper, the proposal algorithm finds the PD source using three sensors attached to one side of the transformer without attenuation of the ultrasonic signal and applying the neural network based geometrical method. The proposed methodology demonstrates the effectiveness and validity on an experimental transformer.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.837-839
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• 2000

Capacitor-run single induction motors have the unbalanced elliptic rotating magnetic field so that it is difficult to analyze the characteristic and calculate the accurate slot leakage reactance of the rotor with the closed slot by using the lumped parameter. In this paper, the characteristic is analyzed by the symmetrical coordinate method in terms of the lumped parameter coupled with the numerical analysis. The secondary parameters are calculated by the one slot pitch boundary condition applying to Finite Element Method (FEM). The analysis results are compared with experimental ones.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.790-795
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• 1998

Fabrication of inverted staggered power TFT devices and electrical characteristic were investigated. 16 fingers with drain and source electrode of TFT and 100V output voltage were designed successfully. It is observed that as $V_g$ increased, $I_d$ increase exponentially. Because of localized deep states of a-Si, $I_d$ shows irregular variation at low voltage. Output and transfer characteristic showed the same as typical variation. But electrical characteristic strongly depend on the channel length and thickness of silicon nitride and amorphous silicon.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.876-878
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• 2000

In this paper, the characteristic of the Linear DC motor(LDM) are analyzed by using 3 Dimensional Equivalent Magnetic Circuit Network (3D EMCN), the movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series, thrust characteristic analysis is performed and the appropriateness of analysed result is verified by comparing with the results of 2 Dimensional Finite Element Method (2D FEM) and experiment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.652-659
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• 2014

This paper deals with characteristic analysis of double sided permanent magnet linear generator using analytical method. We derived magnetic field solutions produced by permanent magnet and armature reaction based on the 2D polar coordinate and magnetic vector potential. based on the derived magnetic field solutions, Induced voltage is obtained when arbitrary sinusoidal input condition. In addition, electrical parameters such as back-EMF constant, resistance, and inductance are obtained. Finally, generating performance characteristic at the rated load and various load is examined by using equivalent circuit.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1012-1014
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• 2003

This paper deals with the characteristic Analysis of synchronous reluctance motors (SynRMs) using coupled Preisach modeling & FEM. The focus of this paper is the characteristic Analysis relative to Inductances and losses on the basis of stator slot number, winding in SynRMs. The coupled Finite Elements Analysis (FEA) & Preisach model has been used to evaluate the nonlinear solution. Comparisons arc given with characteristics of normal distributed winding SynRM and those according to stator slot number, winding in concentrated winding SynRM, respectively.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.221-224
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• 2012

We propose a Readout Integrated Circuit (ROIC), which applies a fixed current bias sensing method to the input stage in order to simplify the circuit structure and the infrared sensor characteristic control. For the sample-and-hold stage to display and control a signal detected by the infrared sensor using a two-dimensional (2D) focal plane array, a differential delta sampling (DDS) circuit is proposed, which effectively removes the FPN. In addition, the output characteristic is improved to have wider bandwidth and higher gain by applying a two-stage variable gain amplifier (VGA). The output characteristic of the proposed device was 23.91 mV/$^{\circ}C$, and the linearity error rate was less than 0.22%. After checking the performance of the ROIC using HSPICE simulation, the chip was manufactured and measured using the SMIC 0.35 um standard CMOS process to confirm that the simulation results from the actual design are in good agreement with the measurement results.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.701-703
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• 1993

This paper describes characteristic analysis of high frequency inverter using zero voltage switching(ZVS) which is one of the methods to reduce switching loss. This study is generally described by introducing normalized control variables. Moreover, many characteristics of analysis results offer importanat data for circuit design. In addition, the result of its characteristic analysis is compared with that from PSpice's simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.4
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• pp.523-531
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• 2019

This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.