• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.197-199
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• 1998

A neuro-fuzzy based torque profile model of SRM with considerably improved accuracy is obtained using the measured data for training. The inferred torque profiles, which comprise magnetic non-linearities, represent the dynamic model of SRM. Then the reference torque signal with optimized waveform and switching angle are decided to control the torque directly. Hence, the presented scheme controls the torque in an instantaneous basis, allowing powerful torque control with minimum torque ripple even during the transient operation of the motor. Simulation and experimental results demonstrating the effectiveness of the proposed torque control scheme are presented.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.153-157
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• 1997

The investigation deals with the process design in cold rolling mill of electric plant. In this study, multiple objective optimization is conducted by a genetic algorithm, where the fitness values are evaluated on the basis of one - dimensional model of flat rolling. The approach is applied to the determination of the process conditions which are optimal with regard to minimization of roll power and maximization of productivity.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.933-935
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• 1997

This paper presents a new approach to dispersed generation installation planning based on a Hereford Ranch Algorithm in a subtransmission system. A method to optimally locate dispersed generations in a meshed network for maximizing the potential benefits is outlined using Hereford Ranch Algorithm and its improvement in this paper. The benefit expressed as a performance index can be minimization of losses. The proposed method was tested for several sample power systems.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.32-33
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• 2013

최근 많은 연구자들이 전력변환회로의 효율을 개선하기 위한 관심을 기울이고 있다. 플라이백 컨버터의 트랜스포머는 누설 인덕턴스에 저장된 에너지를 RCD 회로에서 소모한다. 이는 시스템 효율을 감소시키는 역할을 한다. 따라서 본 논문에서는 저항에 소모되는 에너지를 출력으로 회생시키는 기법에 대해서 제안한다. 제안된 회로의 성능은 모의 실험을 통해 검토한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.586-593
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• 1994

This paper suggests the algorithm for on-line efficiency control of permancent magnet synchronous motors driving the electric vehicles. The existance of unigue d-axis current is verified, which generates the maximum efficiency at operating points of motor. Using the Fibonacci search method, d-axis current converges to the minimization of inverter input power, and to prevent the variation of motor speed in process of the efficiency control, the voltage decoupled control strategy is introduced. Through the experiments, the effects of an efficiency control algorithm are verified.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.131-138
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• 1995

A new technique using integer programming based on fuzzy multi-criteria function is proposed for generator maintenance scheduling. Minimization maintenance delay cost and maximization reserve power are considered for fuzzy multi-criteria function. To obtain an optimal solution for generator maintenance scheduling under fuzzy environment, fuzzy multi-criteria integer programming is used. In the maintenance scheduling, a characteristic feature of the presented approach is that the crisp constraints with uncertainty can be taken into account by using fuzzy set theory and so more flexible solution can be obtained. The effectiveness of the proposed approach is demonstrated by the simulation results.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.296-297
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• 2001

In this paper, the minimization of particle wit introduction of face to face to face type in cleaning. Easy input and change of parameter Monitoring function of process data in process function of 3 moving axis. Return Tank for Chem cal solution

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2141-2145
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• 2015

A new broadcasting signal transmission, which can save its channel bandwidth using compressive sensing(CS), is proposed in this paper. A new compression technique, which uses two dimensional discrete wavelet transform technique, is proposed to get high sparsity of multimedia image. A L1 minimization technique based on orthogonal matching pursuit is also introduced in order to reconstruct the compressed multimedia image. The CS enables us to save the channel bandwidth of wired and wireless broadcasting signal because various transmitted data are compressed using it. A $256{\times}256$ gray-scale image with compression rato of 20 %, which is sampled by 10 Gs/s, was transmitted to an optical receiver through 20-km optical transmission and then was reconstructed successfully using L1 minimization (bit error rate of $10^{-12}$ at the received optical power of -12.2 dB).

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.5
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• pp.57-66
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• 1999

This paper describes a 12b, 50 Msample/s CMOS AID converter using an acquisition-time minimization technique for the high-speed sampling rate of 50 MHz level. The proposed ADC is implemented in a $0.35\mu\textrm{m}$ double-poly five-metal n-well CMOS technology and adopts a typical multi-step pipelined architecture to optimize sampling rate, resolution, and chip area. The speed limitation of conventional pipelined ADCs comes from the finite bandwidth and resulting speed of residue amplifiers. The proposed acquisition-time minimization technique reduces the acquisition time of residue amplifiers and makes the waveform of amplifier outputs smooth by controlling the operating current of residue amplifiers. The simulated power consumption of the proposed ADC is 197 mW at 3 V with a 50 MHz sampling rate. The chip size including pads is $3.2mm\times3.6mm$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.102-110
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• 2012

ZigBee networks developed for low power and short range communication are being used as home network solution for ubiquitous computing. However, as smart phones and tablet PCs have been widely used, WLANs which use same frequency with ZigBee networks have been increasingly used. Therefore, radio frequency interference causes many problems. To solve radio frequency interference problem among ZigBee networks and WLANs, many researches focus on designing interference minimization schemes in ZigBee networks. However, existing schemes have problems that have waste of resource for detecting interference, and have unnecessary time to avoid interference. In this paper, we propose an interference minimization scheme to solve radio frequency interference in ZigBee networks. The proposed scheme detects interference using ACK mechanism to reduce waste of resource, and avoids interference using table driven channel hopping scheme which is faster than existed schemes. The performance of proposed interference minimization scheme is evaluated by using OPNET simulator. Through the simulation result, we prove that proposed scheme has faster channel hopping than existing schemes.