• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.298-300
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• 2002

The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. In particular, the number of available harmonic instruments(Continuous Harmonic Analysis in Real Time : CHART) is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs). This HSE has been applied to the New Zealand AC Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using GAs in the HSE.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.453-455
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• 1997

일반적으로 제철공정에서 각 공정사이의 철판의 속도와 장력은 브라이드롤을 이용하여 제어하는데 여기서 입력 측의 브라이드롤은 장력을 제어하고 출력 측의 브라이드롤은 공정의 속도를 제어한다. 이와 같은 방법은 시스템 기동의 순간을 포함하여 공정속도의 변경이 있을 경우 제철 공정 상에서는 특히 철판의 높은 탄성에 기인하여 시스템이 상당히 불안정하게 된다. 본 논문에서는 각 전동기가 정해진 역할에 따라 독립적으로 장력 혹은 공정속도를 제어하고 장력의 모델링에서 비선형의 요소를 되먹임하여 원래의 시스템을 선형화시켰고 이때 미분관측기를 이용하였다. 이 제어기의 장점은 무엇보다도 독립적인 역할의 분담으로 인해 다수의 전동기로 확장이 용이하도록 하는 것이다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1410-1411
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• 2008

본 연구에서 인덕터에 PGS를 삽입함으로써 인덕터의 품질계수를 향상하여 LNA의 잡음 지수 특성 향상에 대해 연구하였다. 인덕터의 품질계수를 향상시키기 위해 다구찌 실험계획법을 이용하여 인덕터에 삽입되는 PGS의 도체 면적이 최소화 할수록 품질계수를 높일 수 있다. PGS가 없는 인덕터와 PGS를 삽입한 인덕터를 LNA에 적용 시뮬레이션 하였다. PGS가 없는 인덕터 보다는 PGS가 있는 인덕터를 사용함으로써 LNA의 전력 이득과 잡음 지수 특성을 향상시킬 수 있음을 확인하였다.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.6
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• pp.310-313
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• 2004

Spurred by the constant pressure to achieve miniaturization, researchers have designed many different types of compact antennas. One such type is the slotted patch antenna used for dual band operation. In this paper, we propose a novel method of selecting the feeding point of the antenna, which results in superior antenna performance in terms of return loss. Computer simulations verify the validity of the proposed method.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.452-454
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• 2000

In recent years, the Thin Film Transistor Liquid Crystal Display (TFT-LCD) is used in a variety of products as an interfacing device between human and them. Since TFT-LCDs have trend toward larger Panel sizes and higher spatial and/or gray-scale resolution, pixel charging characteristic is very important for the large panel size and high resolution TFT-LCD pixel characteristics. In this paper, both data line precharging method and line time extension (LiTEX) method is applied to Pixel Design Array Simulation Tool (PDAST) and the pixel charging characteristics of TFT-LCD array were simulated, which were compared with the results calculated by both PDAST In which the conventional device model of a-Si TFTs and gate step method is implemented.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1919-1921
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• 1998

In this paper, a control method for field weakening region of induction machine drive which is based on indirect field oriented control was implemented. Also, application method of direct field oriented control in the field weakening region using maximum torque control methods which is adaptable for parking facilities was studied. The implemented method which is based on direct field oriented control method ensures the full utilization of the output torque capability of the machine over the conventional 1/${\omega}_r$ method. And machine drive system can obtain the robustness to motor parameter variation.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1621-1623
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• 1997

The breakdown voltage of SOI RESURF (REduce SURface Field) diode using a SIPOS (Semi Insulating POlycrystalline Silicon) layer is verified in terms of n-drift layer length and surface oxide thickness by device simulator MEDICI, and compared with conventional SOI RESURF diode. Increasing the n-drift layer length, the breakdown voltage of SOI RESURF diode using the SIPOS layer have increased and saturated at $8{\mu}m$. And it has decreased with increasing the surface oxide thickness.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2633-2635
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• 2000

In this paper, a new DNA coding method, namely modified DNA coding method based on the biological DNA and the evolution mechanism of genetic algorithm. In order to evaluate the propose algorithms, for an example, they are applied to the fuzzy control of parallel double inverted pendulum system. Simulation result show the method is effective in finding the fuzzy control rules and is more excellent than conventional methods in control the system.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1745-1747
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• 2000

TFT-LCD simulator, PDAST(Pixel Design Array Simulation Tool) could simulate the effect of the variation on the pixel characteristics. Since feed-through voltage in TFT-LCD can be a serious problem to pixel voltage characteristics, it should be compensated. It is applicable to various kinds of TFT-LCDs and can be used to calculate the spontaneous part of common electrode voltage accurately. Also, PDAST can estimate pixel voltage according to various inversion methods. It allows high-speed calculation and the information obtained from this study could be utilized to design the larger area and finer image quality panel.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2395-2397
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• 2000

In this paper, a new method for color measuring is presented using fuzzy modeling technique. The fuzzy and polynomial inferences are used for obtaining RGB characteristic curve. The eight RGB real data from expert dye-stuff manufacturer, are simulated. The results show that the proposed method is more excellent than other methods, in the color measuring process of textile field.