• Title/Summary/Keyword: Chung-pi

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Quantitative Distribution and Analysis of Methoxylated Flavonoids in Citruses and Korean Chung-pi (감귤류와 한국산 청피에 함유된 Methoxylated Flavonoids의 분석과 정량적 분포)

  • Baik, S.O.;Bock, J.Y.;Chun, H.J.;Jeong, S.I.;Han, W.S.;Kim, I.K.
    • Analytical Science and Technology
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    • v.14 no.4
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    • pp.331-339
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    • 2001
  • Methoxylated flavonoids (sinenstin, nobiletin, tangeretin) were isolated and identified by preparative HPLC, mass and NMR. Chung-pi(I) and Chung-pi(II) contained methoxylated flavonoids most richly. Methoxylated flavonoids in Chung-pi obtained from Korean Milgam increased with fruit maturity, while contents of the methoxylated flavonoids gradually decreased after mid of October.

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A Study on the Fuzzy Modifier of PI Control for Improvement of Tracking properties in Induction Motor System

  • Kim, Yuen-Chung;Ahn, Jeong-Joon;Kim, Jae-Mun;Won, Chung-Yuen;Kim, Young-Real
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.7-10
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    • 1998
  • Because of simple control algorithm and easy implementation, the conventional PI controller has been widely used in industrial application. But, it is very difficult to find the optimal PI control gain. Therefore, in improperly tuned PI controller or parameter variation, to obtain optimal performance, the novel PI controller, which consist of conventional PI controller and 4-rule based fuzzy logic, are presented in this paper. The novel PI controller which exhibits a stabilizing effects on the closed-loop system, has good robustness regarding the improperly tuned PI controller or parameter variation. The simulations are performed to verify the capability of proposed control method on induction motor.

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Robust PI controller and stability analysis for STATCOM system (STATCOM 시스템에 대한 강인 PI 제어기 설계 및 안정성 분석)

  • Kang, Hyun-Jae;Han, Young-Seong;Lee, Young-Ok;Chung, Chung-Choo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.254_255
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    • 2009
  • 본 논문에서는 비선형 특성의 STATCOM 시스템에 대해 강인한 PI 제어기를 설계하였다. 설계된 PI 제어기는 불확실성 변수에 대해 모든 동작 점에서 항상 안정하다는 것을 보드선도, 게인, 위상 여유, Nyquist 선도를 통해 검증하였다.

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Design of Fuzzy PI Controller for Piezo Actuator of Nano Stage (나노 스테이지용 압전 구동기의 퍼지 PI 제어기 설계)

  • Cho, Seong-Yeon;Chung, Chung-Choo
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.629-632
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    • 2003
  • Piezo actuators are mainly used in precision position control system because of their high position resolution. Although there have been many approaches in open loop control of this, those method turn out to be not effective in precision control due to hysteresis and creep. To overcome the problems, closed loop PI control method is used in commercial products. However, it is very difficult to obtain fast response with conventional PI control although piezo actuator has fast response. In this paper, we propose a fuzzy PI control method with the proposed fuzzy PI controller, we obtains faster settling response over the conventional PI controller. We verify the effectiveness of the proposed method with experimental results.

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A Study on Speed Control of Induction Motor using the Fuzzy Modifier (퍼지보상기를 이용한 유도전동기의 속도제어에 관한 연구)

  • Kim, Yuen-Chung;Lee, Sang-Suk;Won, Chung-Yuen;Kim, Young-Real
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2012-2014
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    • 1998
  • The conventional PI controller has been widely used in industrial applications. If a PI control gain is selected suitable, the PI controller shows very good control performance. But it is very difficult to find the optimal PI control gain. Therefore, in this paper, the 4-rule based fuzzy logic modifier of the conventional PI controller are presented. The fuzzy logic modifier which exhibits a stabilizing effects on the closed-loop system, has good robustness regarding the improperly tuned PI controller. The simulation are performed to verify the capability of proposed control method on vector controlled induction motor drive system.

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A Study on Spot Welder of PI Controller Using Evolution Strategy (진화전략에 의한 PI제어기의 스폿용접기에 관한 연구)

  • Kim, Jae-Mun;Kim, Yuen-Chung;Won, Chung-Yuen;Kim, Gyu-Sik
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.531-533
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    • 1997
  • PI(proportional-integral) controller has been extensively used in the industrial field. But in practicle case, it is difficult to tune PI gains. Evolution Strategy(ES) is used as an effective search algorithm in optimization programs. In this paper we proposed a PI controller for Spot welder system using ES with varying search space. ES with varying search space which depends on fitness values at each generation is used to tune PI control parameters. Simulation results show the proposed algorithm has accurate and robust performance with effective search ability.

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Speed Control of Switch Reluctance Motor using Modified Anti-Windup PI Controller and Braking Mode (Modified Anti-Windup PI 제어기와 Braking Mode를 이용한 SRM의 속도 제어)

  • Kim, Hak-Sung;Kim, Yuen-Chung;Kim, Jae-Moon;Yoon, Yong-Ho;Won, Chung-Yuen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.33-39
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    • 2007
  • In this paper, novel topology for fast response of various loads is proposed. The windup phenomenon appears and results in performance degradation when the PI controller output is saturated. A new anti-windup PI controller is proposed to improve the control performance of variable speed motor drives, and it is experimentally applied to the speed control of a hysteresis current-controlled SRM driven by an asymmetry bridge converter. The experimental results show that the speed response has much improved performance, such as small overshoot and fast settling time, over the conventional PI control.

High performance Control of Induction Motor using Hybrid-PI Controller (Hybrid-PI 제어기를 이용한 유도전동기의 고성능 제어)

  • Choii, Jung-Sik;Ko, Jae-Sub;Kim, Kil-Bong;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.260-262
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    • 2006
  • This paper presents Hybrid-PI controller of induction motor drive using fuzzy control. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness, fixed gain PI controller, Hybrid-PI controller proposes a new method based self tuning PI controller. Hybrid-PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of induction motor are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

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Hybrid PI Controller of IPMSM Drive using FAM Controller (FAM 제어기를 이용한 IPMSM 드라이브의 하이브리드 PI 제어기)

  • Ko, Jae-Sub;Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.3
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    • pp.192-197
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    • 2007
  • This paper presents Hybrid PI controller of IPMSM drive using fuzzy adaptive mechanism(FAM) control. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness, fixed gain PI controller, Hybrid PI controller proposes a new method based self tuning PI controller. Hybrid PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

The Characteristic of Control Response of BLDC using a Fuzzy PI Controller (퍼지 PI 제어기를 사용한 BLDC 제어 응답특성)

  • Yoon, Yong-Ho;Kim, Jae-Moon;Kim, Duk-Heon;Won, Chung-Yuen
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.10
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    • pp.1978-1983
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    • 2011
  • BLDC motor is used in a wide variety of industrial and servo applications. Its features and advantages mainly consist in high value of torque/inertia ratio, high efficiency with speed range and high dynamic performance. This paper deals with the speed control of a trapezoidal type brushless DC motor using Fuzzy PI controller. The conventional PI controller has been widely used in industrial applications. If we select a optimal PI control gain, the PI controller shows very good control performance. But it is very difficult to find the optimal PI control gain. Fuzzy control does not need any model of plant and is basically adaptive and gives robust performance for plant parameter variation. Therefore the combinations of conventional PI controller and fuzzy controller seem to be very effective. This paper deals with PI controller with 4-rule based fuzzy controller. The proposed fuzzy PI controller increases the control performance of the conventional PI controller. Simulation and experimental results show that fuzzy PI controller has a good robustness regarding the improper tuned PI controller.