• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.450-453
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• 1996

This research presents a new method of detecting and diagnosing faults of a power plant. Detection of characteristic wave patterns from multichannel instrumentation signals forms the basis of the proposed approach. The dynamics of 500MW drum-type boiler (Boryung coal-fired plant unit #1 and #2) and its control systems are modeled and simulated to generate diverse operation patterns and fault situations and to utilize them for the development of the fault detection algorithms. The results of the boiler system modeling and simulations show a fairly high agreement when compared with some of the actual plant performance test data.

• 한국지능시스템학회논문지
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• 제23권4호
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• pp.348-353
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• 2013

최근들어, 확률론적 최적제어를 포함한 제어이론과 각종 기계학습 기반 인공지능 방법론은 금융공학 분야의 주요 도구로 자리를 잡아 가고 있다. 본 논문에서는 평균회귀 현상을 보이는 시장을 위한 페어 트레이딩 전략 분야와 추세 추종형 트레이딩 전략 분야에 대해 확률론적 최적제어 이론을 활용한 최신 논문 몇 편을 간단히 살펴보고, 보다 융통성 있고 접근성이 좋은 도구를 확보하기 위하여 확률론적 최적제어이론과 기계학습 기법을 동시에 응용하는 전략을 고려한다. 예시를 위하여 실시한 시뮬레이션은 본 논문에서 고려한 전략이 실제 금융시장 데이터를 대상으로 적용될 때 고무적인 결과를 제공할 수 있음을 보여준다.

• 한국지능시스템학회논문지
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• 제2권2호
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• pp.34-41
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• 1992

A robust and reliable learning and reasoning mechanism is addressed based upon fuzzy set theory and fuzzy associative memories. The mechanism stores a priori an initial knowledge base via approximate learning and utilizes this information for decision-making systems via fuzzy inferencing. We called this fuzzy computer architecture a 'fuzzy hypercube' processing all the rules in one clock period in parallel. Fuzzy hypercubes can be applied to control of a class of complex and highly nonlinear systems which suffer from vagueness uncertainty. Moreover, evidential aspects of a fuzzy hypercube are treated to assess the degree of certainty or reliability together with parameter sensitivity.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.250-251
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• 2015

세계적으로 핵 연료와 자연에서 발생되는 화석 연료의 급격한 소비로 인해 자원의 부족으로 대체 에너지가 필요한 실정이다. 현재 세계적으로 많은 대체에너지를 개발 연구하고 있다. 그 중에 기존에 풍력발전 시스템은 대형의 추세로 시스템화가 발전되어 왔으며, 소형의 풍력 발전시스템은 단순하게 풍력발전 원리를 이용하여 발전시스템을 만들어져 왔다. 기존의 소형 풍력 발전시스템은 체계적으로 개발되어 온 것이 아니므로 발전 효율의 저하와 유지보수 문제점으로 많은 곳에서 방취되고 있는 실정이다. 본 논문에서는 소형풍력의 발전 효율 상승과 동시에 태양 에너지를 발전 할 수 있는 하이브리드 발전시스템을 개발하고, 네트워크를 통해 하이브리드 발전시스템을 효율적으로 유지보수 할 수 있는 시스템을 개발하고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1092-1097
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• 2005

In this paper, design approach of PID controller with rejection function against external disturbance in motor control system is proposed using bacterial foraging based optimal algorithm. Up to the present time, PID Controller has been used to operate for AC motor drive because of its implementational advantages in practice and simple structure. However, it is not easy to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error in the industrial system with disturbance. To design disturbance rejection tuning, disturbance rejection conditions based on $H_{\infty}$ are illustrated and the performance of response based on the bacterial foraging is computed for the designed PID controller as ITSE (Integral of time weighted squared error). Hence, parameters of PID controller are selected by bacterial foraging based optimal algorithm to obtain the required response

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.204-208
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• 1990

The digital instrumentation and control system for the large scale system like the power plant must have the form of the heirachical structure. Because most large scale system have many control and process signals and it is distributed in the vade region, it is necessary to partition them into several subsystems. Therefore, the role of SCS(Supervisory Control System) having the functions of controlling and monitoring for the status of subsystems is very important. In this paper, new SCS for the effective control of the large scale system is proposed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.244-249
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• 1998

In this paper, the hybrid state space self-tuning control technique Is studied within the framework of fuzzy systems and dual-rate sampling control theory. We show that fuzzy modeling techniques can be used to formulate chaotic dynamical systems. Then, we develop the hybrid state space self-tuning fuzzy control techniques with dual-rate sampling for digital control of chaotic systems. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the continuous-time optimal state feedback gains, the constructed discrete-time fuzzy system is converted into a continuous-time system. The developed optimal continuous-time control law is then convened into an equivalent slow-rate digital control law using the proposed digital redesign method. The proposed technique enables us to systematically and effective]y carry out framework for modeling and control of chaotic systems. The proposed method has been successfully applied for controlling the chaotic trajectories of Chua's circuit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.404-407
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• 1992

In this thesis, the algorithm of Fuzzy Logic Control(FLC) is applied to the Nonlinear system to implement a system response. Proportional-Integral-Derivative(PID) controller is also used to control the various systems. Look-up table is applied to decide the control input, and the other look-up table is added for saving memories and inference time. Generally, FLC input variables are error(E) and error derivative($\Delta$E). In this algorithm. another Input variable error's second derivative($\Delta^2$E) is added for Robust Fine control.

• International Journal of Control, Automation, and Systems
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• 제1권2호
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• pp.178-183
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• 2003

This work is a modified version of an earlier work that was based on ellipsoidal type feasible sets. Unlike the earlier work, polyhedral types of invariant and feasible sets are adopted to deal with input constraints. The use of polyhedral sets enables the formulation of on-line algorithm in terms of QP (Quadratic Programming), which can be solved more efficiently than semi-def algorithms. A simple numerical example shows that the proposed method yields larger stabilizable sets with greater bounds on disturbances than is the case in the earlier approach.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.885-890
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• 2004

Strictly maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature, the change of the dynamic characteristics in the reheater. Up to the present time, PID Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on tuning of the Controller with disturbance rejection for thermal power plant using immune based multiobjective approach. An ITSE(Integral of time weighted squared error) is used to decide performance of tuning results.