• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.208-211
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• 2006

본 논문에서는 3상 유도전동기의 고장진단을 수행하기 위해 패턴인식에 기반을 둔 진단 알고리즘을 제안한다. 실험 장치는 유도전동기 구동의 고장신호를 얻기 위하여 구축하였으며, 취득된 데이터를 이용하여 진단 알고리즘을 구축하였다. 취득된 데이터 중에서 진단을 위해 사용될 훈련데이터는 퍼지 기반 클러스터링 기법을 이용하여 신뢰성 높은 데이터를 선택하여 고장별 신호를 추출하였다. 진단 알고리즘으로는 데이터를 주성분 분석기법을 적용하였으며, 최종 분류를 위해 Euclidean 기반 거리척도 기법을 이용하였다. 다양한 부하 및 고장신호에 대하여 제안된 방법을 적용하여 타당성을 검증하였다.

• Journal of information and communication convergence engineering
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• v.15 no.2
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• pp.85-90
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• 2017

Expert systems for health diagnosis are only for medical experts who have deep knowledge in the field but we need a self-checking pre-diagnosis system for preventive public health monitoring. Korea Traditional Medicine is popular in use among Korean public but there exist few available health information systems on the internet. A computerized self-checking diagnosis system is proposed to reduce the social cost by monitoring health status with simple symptom checking procedures especially for Korea Traditional Medicine users. Based on the national reports for disease/symptoms of Korea Traditional Medicine, we build a reliable database and devise an intelligent inference engine using fuzzy c-means clustering. The implemented system gives five most probable diseases a user might have with respect to symptoms given by the user. Inference results are verified by Korea Traditional Medicine doctors as sufficiently accurate and easy to use.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.387-389
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• 2009

본 논문에서는 다항식 기반 Radial Basis Function(RBF)신경 회로망을 설계하고 이를 패턴분류 문제에 적용하여 그 성능을 분석한다. 제안된 RBF 신경회로망은 입력층, 은닉층, 출력층으로 이루어진다. 입력층의 연결가중치는 1로서 입력층의 입력벡터는 그대로 은닉층으로 전달되고 은닉층은 FCM(Fuzzy C-means Clustering)방법을 통하여 뉴런의 출력 값으로 내보낸다. 은닉층과 출력층사이의 연결가중치는 상수, 선형식 또는 이차식으로 이루어지며 경사 하강법에 의해 학습되어진다. 네트워크의 최종 출력은 연결가중치와 은닉층 출력의 곱에 의한 퍼지추론의 결과로 얻어진다. 제안된 RBF 신경회로망은 여러 종류의 machine learning 데이터에 적용하여 패턴분류기로서의 성능을 평가받는다.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.99-100
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• 2006

One of the fundamental problems in sensor networks is the deployment of sensor nodes. The Fuzzy C-Means(FCM) clustering algorithm is proposed to determine the optimum location and minimum number of sensor nodes for the specific application space. We performed a simulation using two dimensional L shape model. The actual length of the L shape model is about 100m each. We found the minimum number of 15 nodes are sufficient for the complete coverage of modeled area. We also found the optimum location of each nodes. The real deploy experiment using 15 sensor nodes shows the 95.7%. error free communication rate.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.1-4
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• 2000

본 논문에서는 패턴 데이터(pattern data) 의 분할(partitioning)위하여, 계산량의 단축할 수 있는 효과적인 퍼지 클러스터링 알고리즘(fuzzy clustering algorithm)을 제시한다. 본 논문에 제시된 알고리즘은 두 단계로 수행된다. 첫번째 단계는, 개선된 FCM(Fuzzy C-means)방법에 의해 입력 패턴틀에 대해, 단지 두 번의 반복 수행과정만을 거쳐, 충분히 많은 개수의 초기 클러스터 중 심(center)를 결정한다. 다음 단계에서는, 본 논문에 제시될 클러스터 합치기 알고리즘(cluster merging algorithm)을 통해 각 클러스터의 부피(volume)에 따라 클러스터들을 합치는 과정(merging process)을 하게 된다. 결과적으로 일정한 제한된 개수의 무정형(amorphous)의 클러스터틀의 효과적으로 표현될 수 있다. 본 논문의 마지막에 제시될 실험 결과들은 제시된 방법의 유용성을 보여줄 것이다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1145-1150
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• 1993

In this paper, two methods of fuzzy modeling are prsented to describe the input-output relationship effectively based on relation characteristics utilizing simplified reasoning and neuro-fuzzy reasoning. The methods of modeling by the simplified reasoning and the neuro-fuzzy reasoning are used when the input-output relation of a system is 'crisp' and 'fuzzy', respectively. The structure and the parameter identification in the modeling method by the simplified reasoning are carried out by means of FCM clustering and the proposed GA hybrid scheme, respectively. The structure and the parameter identification in the modeling method by the neuro-fuzzy reasoning are carried out by means of GA and BP algorithm, respectively. The feasibility of the proposed methods are evaluated through simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.526-533
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• 2014

In this study, we introduce design methodology to develop a guidance for issuing heavy rainfall warning by using both RBFNNs(Radial basis function neural networks) and SVR(Support vector regression) model, and then carry out the comparative studies between two pattern classifiers. Individual classifiers are designed as architecture realized with the aid of optimization and pre-processing algorithm. Because the predictive performance of the existing heavy rainfall forecast system is commonly affected from diverse processing techniques of meteorological data, under-sampling method as the pre-processing method of input data is used, and also data discretization and feature extraction method for SVR and FCM clustering and PSO method for RBFNNs are exploited respectively. The observed data, AWS(Automatic weather wtation), supplied from KMA(korea meteorological administration), is used for training and testing of the proposed classifiers. The proposed classifiers offer the related information to issue a heavy rain warning in advance before 1 to 3 hours by using the selected meteorological data and the cumulated precipitation amount accumulated for 1 to 12 hours from AWS data. For performance evaluation of each classifier, ETS(Equitable Threat Score) method is used as standard verification method for predictive ability. Through the comparative studies of two classifiers, neuro-fuzzy method is effectively used for improved performance and to show stable predictive result of guidance to issue heavy rainfall warning.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.146-153
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• 2010

For the indoor location, wireless fingerprinting is most favorable because fingerprinting is most accurate among the technique for wireless network based indoor location which does not require any special equipments dedicated for positioning. As fingerprinting method,k-nearest neighbor(KNN) has been widely applied for indoor location in wireless location area networks(WLAN), but its performance is sensitive to number of neighborsk and positions of reference points(RPs). So possibilistic fuzzy c-means(PFCM) clustering algorithm is applied to improve KNN, which is the KNN/PFCM hybrid algorithm presented in this paper. In the proposed algorithm, through KNN,k RPs are firstly chosen as the data samples of PFCM based on signal to noise ratio(SNR). Then, thek RPs are classified into different clusters through PFCM based on SNR. Experimental results indicate that the proposed KNN/PFCM hybrid algorithm generally outperforms KNN and KNN/FCM algorithm when the locations error is less than 2m.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.1
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• pp.91-96
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• 2015

In this study, we introduce robust face recognition system with illumination variation realized with the aid of CT preprocessing method. As preprocessing algorithm, Census Transform(CT) algorithm is used to extract locally facial features under unilluminated condition. The dimension reduction of the preprocessed data is carried out by using $(2D)^2$PCA which is the extended type of PCA. Feature data extracted through dimension algorithm is used as the inputs of proposed radial basis function neural networks. The hidden layer of the radial basis function neural networks(RBFNN) is built up by fuzzy c-means(FCM) clustering algorithm and the connection weights of the networks are described as the coefficients of linear polynomial function. The essential design parameters (including the number of inputs and fuzzification coefficient) of the proposed networks are optimized by means of artificial bee colony(ABC) algorithm. This study is experimented with both Yale Face database B and CMU PIE database to evaluate the performance of the proposed system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.125-133
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• 2011

For any pattern matching based algorithm in WLAN environment, the characteristics of signal to noise ratio(SNR) to multiple access points(APs) are utilized to establish database in the training phase, and in the estimation phase, the actual two dimensional coordinates of mobile unit(MU) are estimated based on the comparison between the new recorded SNR and fingerprints stored in database. As fingerprinting method, k-nearest neighbor(KNN) has been widely applied for indoor location in wireless location area networks(WLAN), but its performance is sensitive to number of neighbors k and positions of reference points(RPs). So intuitive fuzzy c-means(IFCM) clustering algorithm is applied to improve KNN, which is the KNN/IFCM hybrid algorithm presented in this paper. In the proposed algorithm, through KNN, k RPs are firstly chosen as the data samples of IFCM based on signal to noise ratio(SNR). Then, the k RPs are classified into different clusters through IFCM based on SNR. Experimental results indicate that the proposed KNN/IFCM hybrid algorithm generally outperforms KNN, KNN/FCM, KNN/PFCM algorithm when the locations error is less than 2m.