• Title/Summary/Keyword: Fuzzy Classifier

검색결과 197건 처리시간 0.048초

A design of fuzzy pattern matching classifier using genetic algorithms and its applications (유전 알고리즘을 이용한 퍼지 패턴 매칭 분류기의 설계와 응용)

  • Jung, Soon-Won;Park, Gwi-Tae
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • 제33B권1호
    • /
    • pp.87-95
    • /
    • 1996
  • A new design scheme for the fuzzy pattern matching classifier (FPMC) is proposed. in conventional design of FPMC, there are no exact information about the membership function of which shape and number critically affect the performance of classifier. So far, a trial and error or heuristic method is used to find membership functions for the input patterns. But each of them have limits in its application to the various types of pattern recognition problem. In this paper, a new method to find the appropriate shape and number of membership functions for the input patterns which minimize classification error is proposed using genetic algorithms(GAs). Genetic algorithms belong to a class of stochastic algorithms based on biological models of evolution. They have been applied to many function optimization problems and shown to find optimal or near optimal solutions. In this paper, GAs are used to find the appropriate shape and number of membership functions based on fitness function which is inversely proportional to classification error. The strings in GAs determine the membership functions and recognition results using these membership functions affect reproduction of next generation in GAs. The proposed design scheme is applied to the several patterns such as tire tread patterns and handwritten alphabetic characters. Experimental results show the usefulness of the proposed scheme.

  • PDF

Fault Diagnosis for Agitator Driving System in a High Temperature Reduction Reactor

  • Park Gee Young;Hong Dong Hee;Jung Jae Hoo;Kim Young Hwan;Jin Jae Hyun;Yoon Ji Sup
    • Nuclear Engineering and Technology
    • /
    • 제35권5호
    • /
    • pp.454-470
    • /
    • 2003
  • In this paper, a preliminary study for development of a fault diagnosis is presented for monitoring and diagnosing faults in the agitator driving system of a high temperature reduction reactor. In order to identify a fault occurrence and classify the fault cause, vibration signals measured by accelerometers on the outer shroud of the agitator driving system are firstly decomposed by wavelet transform (WT) and the features corresponding to each fault type are extracted. For the diagnosis, the fuzzy ARTMAP is employed and thereby, based on the features extracted from the WT, the robust fault classifier can be implemented with a very short training time - a single training epoch and a single learning iteration is sufficient for training the fault classifier. The test results demonstrate satisfactory classification for the faults pre-categorized from considerations of possible occurrence during experiments on a small-scale reduction reactor.

Fuzzy Behavior Knowledge Space for Integration of Multiple Classifiers (다중 분류기 통합을 위한 퍼지 행위지식 공간)

  • 김봉근;최형일
    • Korean Journal of Cognitive Science
    • /
    • 제6권2호
    • /
    • pp.27-45
    • /
    • 1995
  • In this paper, we suggest the "Fuzzy Behavior Knowledge Space(FBKS)" and explain how to utilize the FBKS when aggregating decisions of individual classifiers. The concept of "Behavior Knowledge Space(BKS)" is known to be the best method in the context that each classifier offers only one class label as its decision. However. the BKS does not considers measurement value of class label. Furthermore, it does not allow the heuristic knowledge of human experts to be embedded when combining multiple decisions. The FBKS eliminates such drawbacks of the BKS by adapting the fwzy concepts. Our method applies to the classification results that contain both class labels and associated measurement values. Experimental results confirm that the FBKS could be a very promising tool in pattern recognition areas.

  • PDF

Credit Risk Evaluations of Online Retail Enterprises Using Support Vector Machines Ensemble: An Empirical Study from China

  • LI, Xin;XIA, Han
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제9권8호
    • /
    • pp.89-97
    • /
    • 2022
  • The e-commerce market faces significant credit risks due to the complexity of the industry and information asymmetries. Therefore, credit risk has started to stymie the growth of e-commerce. However, there is no reliable system for evaluating the creditworthiness of e-commerce companies. Therefore, this paper constructs a credit risk evaluation index system that comprehensively considers the online and offline behavior of online retail enterprises, including 15 indicators that reflect online credit risk and 15 indicators that reflect offline credit risk. This paper establishes an integration method based on a fuzzy integral support vector machine, which takes the factor analysis results of the credit risk evaluation index system of online retail enterprises as the input and the credit risk evaluation results of online retail enterprises as the output. The classification results of each sub-classifier and the importance of each sub-classifier decision to the final decision have been taken into account in this method. Select the sample data of 1500 online retail loan customers from a bank to test the model. The empirical results demonstrate that the proposed method outperforms a single SVM and traditional SVMs aggregation technique via majority voting in terms of classification accuracy, which provides a basis for banks to establish a reliable evaluation system.

A Text Detection Method Using Wavelet Packet Analysis and Unsupervised Classifier

  • Lee, Geum-Boon;Odoyo Wilfred O.;Kim, Kuk-Se;Cho, Beom-Joon
    • Journal of information and communication convergence engineering
    • /
    • 제4권4호
    • /
    • pp.174-179
    • /
    • 2006
  • In this paper we present a text detection method inspired by wavelet packet analysis and improved fuzzy clustering algorithm(IAFC).This approach assumes that the text and non-text regions are considered as two different texture regions. The text detection is achieved by using wavelet packet analysis as a feature analysis. The wavelet packet analysis is a method of wavelet decomposition that offers a richer range of possibilities for document image. From these multi scale features, we adapt the improved fuzzy clustering algorithm based on the unsupervised learning rule. The results show that our text detection method is effective for document images scanned from newspapers and journals.

A Study on the On-Line Fuzzy ULTC Controller Design Based on Multiple Load Center Points (다중 부하중심점에 기반한 온라인 퍼지 ULTC 제어기 설계에 대한 연구)

  • Ko, Yun-Seok
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • 제55권12호
    • /
    • pp.514-521
    • /
    • 2006
  • The existing ULTC operation control strategy based on the measured data deteriorates the voltage compensation capability making the efficient corresponding to the load variation difficult by following the fixed load center point voltage. Accordingly, this paper proposes a new on-line fuzzy ULTC controller based on the designed multiple load center points which can improve the voltage compensation capability of ULTC and minimize voltage deviation by moving in real-time the load center point according to the load variation to an adequate position among the multiple load center points designed using the clustering technique. The Max-Min distance technique is adopted as the clustering technique for the decision of multiple load points from measured MTr load current and PTr voltage, and the minimum distance classifier is adopted for the decision of fuzzy output membership function. To verify the effectiveness of the proposed strategy, Visual C++ MFC-based simulation environments is developed. Finally, the superiority the proposed strategy is proved by comparing the fuzzy ULTC operation control results based on multiple load center points with the existing ULTC operation control results based on fixed load center point using the data for three day.

Classification of Music Data using Fuzzy c-Means with Divergence Kernel (분산커널 기반의 퍼지 c-평균을 이용한 음악 데이터의 장르 분류)

  • Park, Dong-Chul
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • 제46권3호
    • /
    • pp.1-7
    • /
    • 2009
  • An approach for the classification of music genres using a Fuzzy c-Means(FcM) with divergence-based kernel is proposed and presented in this paper. The proposed model utilizes the mean and covariance information of feature vectors extracted from music data and modelled by Gaussian Probability Density Function (GPDF). Furthermore, since the classifier utilizes a kernel method that can convert a complicated nonlinear classification boundary to a simpler linear one, he classifier can improve its classification accuracy over conventional algorithms. Experiments and results on collected music data sets demonstrate hat the proposed classification scheme outperforms conventional algorithms including FcM and SOM 17.73%-21.84% on average in terms of classification accuracy.

Robust Algorithms for Combining Multiple Term Weighting Vectors for Document Classification

  • Kim, Minyoung
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제16권2호
    • /
    • pp.81-86
    • /
    • 2016
  • Term weighting is a popular technique that effectively weighs the term features to improve accuracy in document classification. While several successful term weighting algorithms have been suggested, none of them appears to perform well consistently across different data domains. In this paper we propose several reasonable methods to combine different term weight vectors to yield a robust document classifier that performs consistently well on diverse datasets. Specifically we suggest two approaches: i) learning a single weight vector that lies in a convex hull of the base vectors while minimizing the class prediction loss, and ii) a mini-max classifier that aims for robustness of the individual weight vectors by minimizing the loss of the worst-performing strategy among the base vectors. We provide efficient solution methods for these optimization problems. The effectiveness and robustness of the proposed approaches are demonstrated on several benchmark document datasets, significantly outperforming the existing term weighting methods.

Learning of Cooperative Behavior between Robots in Distributed Autonomous Robotic System

  • Hwang, Chel-Min;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제5권2호
    • /
    • pp.151-156
    • /
    • 2005
  • This paper proposes a Distributed Autonomous Robotic System(DARS) based on an Artificial Immune System(AIS) and a Classifier System(CS). The behaviors of robots in the system are divided into global behaviors and local behaviors. The global behaviors are actions to search tasks in given environment. These actions are composed of two types: aggregation and dispersion. AIS decides one among these two actions, which robot should select and act on in the global. The local behaviors are actions to execute searched tasks. The robots learn the cooperative actions in these behaviors by the CS in the local one. The proposed system will be more adaptive than the existing system at the viewpoint that the robots learn and adapt the changing of tasks.

Distance Sensitive AdaBoost using Distance Weight Function

  • Lee, Won-Ju;Cheon, Min-Kyu;Hyun, Chang-Ho;Park, Mi-Gnon
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제12권2호
    • /
    • pp.143-148
    • /
    • 2012
  • This paper proposes a new method to improve performance of AdaBoost by using a distance weight function to increase the accuracy of its machine learning processes. The proposed distance weight algorithm improves classification in areas where the original binary classifier is weak. This paper derives the new algorithm's optimal solution, and it demonstrates how classifier accuracy can be improved using the proposed Distance Sensitive AdaBoost in a simulation experiment of pedestrian detection.