• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.310-316
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• 1998

본 논문에서는 기존의 퍼지 제어규칙에비해 좋은 성능을 갖는 T-S(Takagi-Sugeno)퍼지 모델을 자기조직화 지도와 역전파 신경망을 이용하여 표현하고 제어기 구현을 위한 규칙의 자동 생성 방법을 제안한다. 제안된 방법은 신경망에 기초하여 T-S 퍼지 제어 규칙을 포현하므로써 학습 기능을 이용하여 지식 획득을 용이하게 하고, 입력 변수간의 퍼지 관계에 기반 하여 추론이 이루어지므로 각 퍼지 변수에 대한 소속 함수의 정의 과정이 불필요하게 된다. 또한 제어기로 구현되었을 때 규칙의 수나 퍼지화 및 비퍼지화 등이 구성된 추론망을 통하여 자동으로 수행될 수 있다. 때문에 퍼지 시스템의 구현이 쉽게 이루어 질 수 있게 한다. 제안된 방법을 자동차 궤도 안정화 모의 실험에 적용해 봄으로써 추론망이 규칙을 생성하여 타당한 추론을 하게 됨을 확인한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.110-113
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• 2005

본 논문은 가중 퍼지소속함수 기반 신경망(Neural Network with Weighted fuzzy Membership Funcstions, NEWFM)을 이용하여 심전도 신호로부터 조기심실수축(Premature Ventricular Contraction, PVC)을 판별하는 퍼지규칙을 추출하고 있다. NEWFM은 자기적응적(self adaptive) 가중 퍼지소속함수를 가지고 주어진 입력 데이터로부터 학습하여 퍼지규칙을 생성하고 이를 기반으로 정상 파형과 PVC 파형을 구분한다. 분류 성능 평가를 위하여 MIT/BIH 부정맥 데이터 베이스를 사용하였으며, NEWFM의 입력은 심전도의 파형에 웨이블릿 변환을 적용하여 추출된 웨이블릿 계수를 사용하였다. 여기에 비중복면적 분산 측정법을 적용하여 중요도가 낮은 계수를 제거하면서 최소의 m 개 특징입력만을 사용한 하이퍼박스로 단순화 시킨다. 이러한 방법으로 추출된 2개의 웨이블릿 계수를 사용한 퍼지규칙은 $96\%$의 PVC 분류성능을 보여준다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.371-373
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• 2003

웹 문서를 분류하는 목적은 특정 주제별로 중요한 문서들을 구분하려는 것과 사용자의 선호도를 바탕으로 개인화를 하려는 것으로 나누어 볼 수 있다. 특히, 웹의 효율적인 탐색을 위해 사용자가 관심 있어 할 웹 문서를 분류하는 것은 중요하다 일반적으로 하나의 웹 문서는 특징 추출방법에 의해 문서 벡터로 표시되며 사용자의 선호여부나 주제번호를 클래스로 삼는다. 사용자가 선호도를 표시한 웹 문서를 사용하여 새로운 웹 문서의 선호 여부를 예측하기 위해 자기 구성지도(SOM)를 사용하면, 시각적으로 구조를 보여주어 데이터 사이의 관계를 효과적으로 이해할 수 있다. 그러나 SOM은 노드의 개수와 구조를 자동적으로 결정하지 못하는 단점이 있기 때문에, SOM의 장점을 활용하면서 자동적으로 구조를 결정하기 위해 구조적응 자기구성지도(SASOM)를 이용한다. 보다 나은 성능과 다양한 해석을 위해, 여러 개의 SASOM을 서로 다른 특징추출 방법을 이용하여 학습시킨 후 사용자가 주관적으로 분류기의 중요도를 결정할 수 있는 퍼지적분을 사용하여 결합하였다. UCI Syskill & Webert 데이터에 대한 실험결과 기존의 DT, MLP, naive Bayes 분류기 보다 향상된 성능을 보였다.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.821-832
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• 1998

This study investigates the prediction of daily water supply, which is a necessary for the efficient management of water distribution system. Fuzzy neuron, namely artificial intelligence, is a neural network into which fuzzy information is inputted and then processed. In this study, daily water supply was predicted through an adaptive learning method by which a membership function and fuzzy rules were adapted for daily water supply prediction. This study was investigated methods for predicting water supply based on data about the amount of water supplied to the city of Kwangju. For variables choice, four analyses of input data were conducted: correlation analysis, autocorrelation analysis, partial autocorrelation analysis, and cross-correlation analysis. Input variables were (a) the amount of water supplied (b) the mean temperature, and (c)the population of the area supplied with water. Variables were combined in an integrated model. Data of the amount of daily water supply only was modelled and its validity was verified in the case that the meteorological office of weather forecast is not always reliable. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 18.35% and the average error was lower than 2.36%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.211-213
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• 1993

In this paper, we proposed a design method of self-learning fuzzy logic controller using fuzzy neural network. The parameters of membership function in premise are modified by descent method and also consequent parameters by learning mechanism of animal conditioning theory. The proposed method is applied to pole balancing system in order to confirm the feasibility.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.688-694
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• 2005

In this Paper, we Propose a new neuro-fuzzy modeling using clustering-based learning method. In the proposed clustering method, number of clusters is automatically inferred and its parameters are optimized simultaneously, Also, a neuro-fuzzy model is learned based on clustering information at same time. In the previous modelling method, clustering and model learning are performed independently and have no exchange of its informations. However, in the proposed method, overall neuro-fuzzy model is generated by using both clustering and model learning, and the information of modelling output is used to clustering of input. The proposed method improve the computational load of modeling using Subtractive clustering method. Simulation results show that the proposed method has an effectiveness compared with the previous methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.397-406
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• 2000

Genetic algorithm is used as a means of search, optimization md machine learning, its structure is simple but it is applied to various areas. And it is about an active and effective controller which can flexibly prepare for changeable circumstances. For this study, research about an action base system evolving by itself is also being considered. There is to have a problem that depended entirely on heuristic knowledge of expert forming membership function and control rule for fuzzy controller design. In this paper, for forming the fuzzy control to perform self-organization, we tuned the membership function to the most optimal using a genetic algorithm(GA) and improved the control efficiency by the self-correction and generation of control rules.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.830-836
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• 2006

In this paper described an auto tuning neuro-fuzzy PID controller based neural network. The PID type controller has been widely used in industrial application due to its simply control structure, easy of design, and inexpensive cost. However, control performance of the PID type controller suffers greatly from high uncertainty and nonlinearity of the system, large disturbances and so on. In this paper will design to take advantage of neural network fuzzy theory and pid controller auto toning technique. The value of initial scaling factors of the proposed controller were determined on the basis of the conventional PID controller parameters tuning methods and then they were adjusted by using neural network control techniques. This controller simple structure and computational complexity are less, and also application is easy and performance is excellent in system that is strong and has nonlinearity to system dynamic behaviour change or disturbance. Finally, the proposed auto tuning neuro-fuzzy controller is applied to magnetic levitation. Simulation results demonstrated that the control performance of the proposed controller is better than that of the conventional controller.

• Journal of KIISE:Software and Applications
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• v.31 no.1
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• pp.61-70
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• 2004

It is difficult to find an appropriate web site because exponentially growing web contains millions of web documents. Personalization of web search can be realized by recommending proper web sites using user profile but more efficient method is needed for estimating preference because user's evaluation on web contents presents many aspects of his characteristics. As user profile has a property of non-linearity, estimation by classifier is needed and combination of classifiers is necessary to anticipate diverse properties. Structure adaptive self-organizing map (SASOM) that is suitable for Pattern classification and visualization is an enhanced model of SOM and might be useful for web mining. Fuzzy integral is a combination method using classifiers' relevance that is defined subjectively. In this paper, estimation of user profile is conducted by using ensemble of SASOM's teamed independently based on fuzzy integral and evaluated by Syskill ＆ Webert UCI benchmark data. Experimental results show that the proposed method performs better than previous naive Bayes classifier as well as voting of SASOM's.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.172-175
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• 1996

In the paper is proposed a hierarchical self-learning fuzzy controller for balancing and position control of an circular inverted pendulum system. To stabilize the pendulum at a specified position, the hierarchical fuzzy controller consists of a supervisory controller, a self-learning fuzzy controller, and a forced disturbance generator. Simulation example shows the effectiveness of the proposed method.