• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.22.1-22
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• 2001

In this paper we present Multiple-Channel Active Noise Control[ANC] system by employing Independent Component Analysis[ICA] and Adaptive Network Fuzzy Inference System[ANFIS]. ICA is widely used in signal processing and communication and it use prewhiting and appropriate choice of non-linearities, ICA can separate mixed signal. ANFIS controller is trained with the hybrid learning algorithm to optimize its parameters for adaptively canceling noise. This new method which minimizes a statistical dependency of mutual information(MI) in mixed low frequency noise signal and there is no need to secondary path modeling. The proposed implementations achieve more powerful and stable noise reduction than Filtered-X LMS algorithms which is needed for LTI assumption and precise secondary error

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.513-514
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• 2005

In plasma processing reactors, it is common practice to control plasma density and ion bombardment energy by manipulating excitation voltage and frequency. In this paper, a dually excited capacitively coupled rf plasma reactor is self-consistently simulated with a three moment model. Effects of phase differences between primary and secondary voltage waves, simultaneously modulated at various combination of commensurate frequencies, on plasma properties are investigated. The simulation results show that plasma potential and density as well as primary self-dc bias are nearly unaffected by the phase lag between the primary and the secondary voltage waves. The results also show that, with the secondary frequency substantially lower than the primary frequency, secondary self-dc bias remains constant regardless of the phase lag. As the secondary frequency approaches to the primary frequency, however, the secondary self-dc bias becomes greatly altered by the phase lag, and so does the ion bombardment energy at the secondary electrode. These results demonstrate that ion bombardment energy can be more carefully controlled through plasma simulation.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.824-833
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• 2012

In this paper, a coordinated state-of-charge (SOC) control strategy for the energy storage system (ESS) operating under microgrid islanded mode to stabilize the frequency and voltage was proposed. The proposed SOC control loop is made up of PI controller, which uses a SOC state of the energy storage system as an input and an auxiliary reference value of secondary control as an output. The SOC controller changes the auxiliary reference value of secondary control to charge or discharge the ESS. To verify the proposed control strategy, PSCAD/EMTDC simulation study was performed. The simulation results show that the SOC of the ESS can be regulated at the desired operating range without degrading the stabilizing control performance by proposed coordinated SOC control method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.138-140
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• 2018

Parallel distributed generators (DGs) in the islanded microgrid are generally operated autonomously by means of the droop control scheme. However, the traditional droop control methods which use the P-${\omega}$ and Q-E curve to share power between DGs are still concerned to improve the accuracy of reactive power sharing. Moreover, the uncontrolled harmonic power reduces the point of common coupling (PCC) voltage quality and microgrid stability. In order to solve these problems, this paper proposes an enhanced PCC harmonic control strategy and an improved reactive power sharing control scheme. Based on the low bandwidth communications, a secondary control is implemented with both central controller and local controller. The effectiveness of the proposed control scheme is analyzed through the simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.47-48
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• 2016

Parallel distributed generators (DGs) in the islanded micro-grid are normally controlled with the aid of the droop control scheme. However, the traditional droop control methods which use the P-${\omega}$ and Q-E curve to share power between DGs are still concerned to improve the accurate of reactive power sharing and variation of frequency and voltage at the point of common coupling (PCC). This paper proposes a control scheme to solve the limitation of microgrid in islanded operation such as reactive power sharing accuracy and PCC voltage and frequency restoring. In order to achieve the control objective, a secondary control is implemented with both central controller and local controller by using the low bandwidth communications. The effectiveness of the proposed control scheme is analyzed through the simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.267-269
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• 1996

Servo systems became indispensable to applications such as industrial robots and numerically controlled machinery. Especially, induction motor drives are widely used as ac-servo system owing to the fact that it is maintenance-free. At the present time, Quick torque control methods such as vector control have been employed that enables an induction motor to attain as quick torque response as a dc motor. However, these methods can not be realized without knowing several motor parameters accurately, because the methods need them to calculate flux or voltage command. Most of all, secondary resistance has to be identified accurately, because it's value varies greatly for operation of induction motors. In this paper, a new identification method of secondary resistance based on quick torque control system of induction motors is proposed. The proposed method is derived theoretically from motor circuit equation and can be realized very simply by detecting primary current and voltage command of the motor. Through the numerical simulation considered using PWM inverter, the validity of the proposed method was successfully confirmed.

• 한국연소학회지
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• 제3권1호
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• pp.59-69
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• 1998

The results of study on the active control of naturally occurring combustion oscillations with a single dominant frequency in an atmospheric dump combustor are presented. Control was achieved by an oscillatory infection of secondary fuel at the dump plane. A high speed solenoid valve with a maximum frequency of 250Hz was used as the actuator and a sound level meter, located at the combustor exit, measured the pressure fluctuations which served as the feedback signal for the control loop. Instability characteristics were mapped over a range of mean mixing section velocities from 6.7 m/s-9.3 m/s and with three mixing conditions. Different fuel/air mixing conditions were investigated by introducing varying percentages of primary fuel at two locations, one at the entrance to the mixing section and one 6 mixing tube diameters upstream of the dump plane. Control studies were conducted at a mean velocity of 9.3 m/s, with an air temperature of $415^{\circ}C$, and from flame blowout to the stoichiometric condition.

• 한국의류학회지
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• 제29권1호
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• pp.1-12
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• 2005

This study was to suggest a feasible sizing system of infants and children's swim-suits. The basic body dimensions were selected after surveying the swimsuit manufacturers. The control dimensions and the secondary dimensions were taken from the 1997 National Anthropometric Survey data for the establishment of the sizing system. While in the current market swimsuit sizes were generally measured by the hip circumference for boys, and the bust and hip circumference for girls, the height was selected in this study as the control dimension because the height is well recognized by the customers and the KS standards specify the height to be the control dimension for infant's and children's wear. In the new sizing system of this study, the height was a control dimension, and hip was selected as a secondary dimension for boys. and bust and hip were selected as secondary dimensions for girls. Conclusively, in this study we suggest 12 sizes in case of 5cm height interval by the KS sizing system and 7 sizes in case of loom height interval by the current market sizing system, based on the height as a control dimension, for a standard swim-suit sizing system for infants and children.

• 한국멀티미디어학회논문지
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• 제6권7호
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• pp.1131-1138
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• 2003

능동소음제어는 원치 않는 소음에 대하여 2차 소음으로 상쇄 간섭을 발생시켜 소음을 제거하는 방법이다. 일반적으로 능동소음제어기의 성능은 2차 소음이 주 소음을 얼마나 잘 추정하는가에 따라 결정된다. 2차 소음은 스피커를 통해 발생되며 마이크를 통해 오차 신호를 수음한다. 일반적으로 스피커와 마이크의 전달특성은 이상적이지 못하기 때문에 신호를 왜곡시켜 능동소음제어기의 성능이 저하된다. 본 논문에서는 스피커와 마이크의 전달특성을 고려한 단일센서 능동소음제어기를 제안한다. 스피커와 마이크의 전달특성에 의한 2차 소음의 왜곡을 줄이기 위하여 적응 역모델링 기법으로 전달 특성을 추정하고 주 소음은 Kalman필터를 이용하여 추정한다. 실험을 통하여 제안하는 단일센서 능동소음제어기가 효과적으로 소음을 감쇠시킴을 보인다.

• 한국정보컨버전스학회:학술대회논문집
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• 한국정보컨버전스학회 2008년도 International conference on information convergence
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• pp.39-42
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• 2008

G protein-coupled receptor(GPCR) family is a cell membrane protein, and plays an important role in a signaling mechanism which transmits external signals through cell membranes into cells. Now, it is estimated that there may be about 800-1000 GPCRs in a human genome. But, GPCRs each are known to have various complex control mechanisms and very unique signaling mechanisms. GPCRs are involved in maintaining homeostasis of various human systems including an endocrine system or a neural system and thus, disorders in activity control of GPCRs are thought to be the major source of cardiovascular disorders, metabolic disorders, degenerative disorders, carcinogenesis and the like. As more than 60% of currently marketed therapeutic agents target GPCRs, the GPCR field has been actively explored in the pharmaceutical industry. Structural features, and class and subfamily of GPCRs are well known by function, and accordingly, the most fundamental work in studies identifying the previous GPCRs is to classify the GPCRs with given protein sequences. Studies for classifying previously identified GPCRs more easily with mathematical models have been mainly going on. Considering that secondary sequences of proteins, namely, secondary binding structures of amino acids constituting proteins are closely related to functions, the present paper does not place the focus on primary sequences of proteins as previously practiced, but instead, proposes a method to transform primary sequences into secondary structures and compare the secondary structures, and then detect an unknown GPCR assumed to have a same function in databases of previously identified GPCRs.