• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.312-319
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• 2004

The optimum dosage control is presumably the goal of every water treatment plant. However it is difficult to determine the dosage rate of coagulant, due to nonlinearity, multivariables and slow response characteristics, etc. To deal with this difficulty, the real number genetic-fuzzy system was used in determining the dosage rate of the coagulant. The genetic algorithms are excellently robust in complex optimization problems. Since it uses randomized operators and searches for the best chromosome without auxiliary informations from a population which consists of codings of parameter set. To apply this algorithms, we made the real number rule table and membership function from the actual operation data of the water treatment plant. We determined optimum dosages of coagulant(LAS) using the fuzzy operation and compared them with the dosage rate of the actual operation data.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.236-245
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• 2005

This paper was developed the discrete optimum design program by the refined fuzzy-genetic algorithms based on the genetic algorithms and fuzzy theory. The optimum design of this paper can perform both size and shape optimum design for planar and spacial steel structures. In this paper, the objective function is the weight of steel structures and the constraints are the design limits defined by design and buckling strengths, displacements and thicknesses. The design variables are dimensions and coordinates of steel sections. Design examples are given to show the applicability of the discrete optimum design program of this paper.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.731-734
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• 2017

GA(Genetic Algorithm)는 자연계 진화 과정의 적자생존의 유전적 부호화 및 처리과정을 모델링함으로서 해석적으로 처리하기 힘든 문제의 최적화에 널리 이용하고 있으며, 퍼지제어에서 룰의 선택에도 적용된다. 본 논문에서는 일반적인 GA방법에 자료의 유사성을 체크하는 방법을 도입하여 Fuzzy Rule선택 환경에 적용하고 시뮬레이션을 통해 이를 확인한다. 시뮬레이션 결과 제안된 SFRGA(Similarity Fuzzy Rule Genetic Algorithm)방법은 일반적 GA방법보다 단축된 지연시간 효과와 부수적으로 조기포화 현상(premature convergence)의 감소 및 자동 배정 퍼지 클리스터링(Fuzzy clustering)의 가능성을 얻을 수 있었다.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.730-735
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• 2006

This paper proposes a time series prediction method for the short term electrical load will) the fuzzy system and the genetic algorithm. At first, we obtain the optimal fuzzy membership function using the genetic algorithm. With the optimal fuzzy rules and its input differences, a better time prediction system may be obtained. We obtain good results for the time prediction of the short term electric load by the proposed algorithm. In addition we implement the graphic user interface for the proposed algorithms. Finally, we implement the regional prediction system for the electric load.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.432-441
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• 2000

This paper deals with the fuzzy modeling for the complex and uncertain nonlinear systems, in which conventional and mathematical models may fail to give satisfactory results. Genetic algorithm has been used to identifY parameters and structure of fuzzy model because it has the ability to search optimal solution somewhat globally. The genetic algorithm, however, has a problem, which optimization process can be premature convergence in the case of lack of genetic divergence of population. Virus- evolutionary genetic algorithm(VEGA) could be a strategy against this local convergence. Therefore, we use VEGA for fuzzy modeling. In this method, local information is exchanged in population so that population can sustain genetic divergence. finally, to prove the theoretical hypothesis, we provide numerical examples to evaluate the feasibility and generality of fuzzy modeling using VEGA.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.3
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• pp.221-226
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• 2006

In this paper, we study an approach to design a Fuzzy PI controller in HVDC(High Voltage Direct Current) system. In the rectifier of traditional HVDC system, turning on, turning off, triggering and protections of thyristors have lots of problems that can make the dynamic instability and cannot damp the dynamic disturbance efficiently. In order to solve the above problems, we adapt Fuzzy PI controller for the fire angle control of rectifier. The performance of the Fuzzy PI controller is sensitive to the variety of scaling factors. The design procedure dwells on the use of evolutionary computing(Genetic Algorithms, GAs). Then we can obtain factors of the Fuzzy PI controller by Genetic Algorithms. A comparative study has been performed between Fuzzy PI controller and traditional PI controller, to prove the superiority of the proposed scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.363-371
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• 1999

In this paper proposes the optimal fuzzy controller design method using the genetic algorithm. Proposed method is that fuzzy rules and input - output scaling factors of the fuzzy controller are determined by using genetic algorithm that is very effectively in the optimization problem. The optimal fuzzy rules of servo system uses the fitness function which are the performance index in fuzzy controller. In order to verify excellent control performances of the proposed control method, we compare the control performance and characteristics about the proposed control method with a conventional fuzzy control method through a lot of simulations and experiments with one link manipulator.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.121-126
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• 2006

In the recent years, the development of computer-controlled suspension dampers and actuators has improved the trade-off between the vehicle handling and ride comfort, and has led to the development of various damper control policies. The skyhook control is an effective control strategy for suppressing vehicle vibration. In this study, a fuzzy skyhook control is proposed and tuned by a genetic algorithm to improve ride comfort. The proposed fuzzy skyhook control is applied to a quarter-car model in order to compare its performance with continuous skyhook suspensions. To obtain optimized fuzzy skyhook control, scale factors and in-out membership functions are tuned by a genetic algorithm. The simulation results show that the fuzzy skyhook control offers more effective suspension performance over the continuous skyhook control.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.322-324
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• 2005

In this paper, we introduce the advanced Self-Organizing Fuzzy Polynomial Neural Network based on optimized FPN by evolutionary algorithm and discuss its comprehensive design methodology involving mechanisms of genetic optimization, especially genetic algorithms (GAs). The proposed model gives rise to a structurally and parametrically optimized network through an optimal parameters design available within Fuzzy Polynomial Neuron(FPN) by means of GA. Through the consecutive process of such structural and parametric optimization, an optimized and flexible the proposed model is generated in a dynamic fashion. The performance of the proposed model is quantified through experimentation that exploits standard data already used in fuzzy modeling. These results reveal superiority of the proposed networks over the existing fuzzy and neural models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.1003-1006
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• 2003

This paper proposed An auto fuzzy rule-base extraction method using genetic algorithm. The suggested method is an auto fuzzy rule-base extration method neither expert advise fuzzy rule-base nor trial and error fuzzy rule-base. In order to confirm the validity of proposed method, we have applicated dc motor control and confirmed effective.