Presentation 2001/10/11
Unsupervised learning for single hypothesis problem via mixtures of modified quadratic discriminant functions
Tsuyoshi KATO, Shinichiro OMACHI, Hirotomo ASO,
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Abstract(in English) This paper shows that the performance of the single hypothesis scheme-it classifies unknown patterns to the specified class called target class-can be improved by estimating the probabilistic distribution of nontarget class using additional unlabeled training patterns that are available at no extra cost. Furthermore, our method achives comparable recognition accuracy to the supervised classifier, yet requires no labeled nontarget patterns for training. We introduce an algorithm for learning nontargets's pdf.from unlabeled patterns based on Expectation-Maximization and the proposed stochastic model, the mixture of modified quadratic discriminant function(MQDF). The MQDF is well-known as one of the state-of-the-art classifiers, however, it suffers from the weakness for multi-modal distribution. The mixture of MQDF overcomes this problem, yet which reteins the excellent classification performance. We demonstrate the practicality and accuracy of the mixture of MQDF estimated by the proposed unsupervised learning using the artificial and the real world databases. Forthermore, the proposed algorithm is also tested on the letter-image identification problem.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) single hypothesis problem / mixture of modified quadratic discriminant funcions / unsupervised learning / Expectation-Maximization algorithm / letter-image identifier
Paper # PRMU2001-103,NC2001-53
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Conference Information
Committee PRMU
Conference Date 2001/10/11(1days)
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Paper Information
Registration To Pattern Recognition and Media Understanding (PRMU)
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Unsupervised learning for single hypothesis problem via mixtures of modified quadratic discriminant functions
Sub Title (in English)
Keyword(1) single hypothesis problem
Keyword(2) mixture of modified quadratic discriminant funcions
Keyword(3) unsupervised learning
Keyword(4) Expectation-Maximization algorithm
Keyword(5) letter-image identifier
1st Author's Name Tsuyoshi KATO
1st Author's Affiliation Graduate School of Engineering, Tohoku University()
2nd Author's Name Shinichiro OMACHI
2nd Author's Affiliation Graduate School of Engineering, Tohoku University
3rd Author's Name Hirotomo ASO
3rd Author's Affiliation Graduate School of Engineering, Tohoku University
Date 2001/10/11
Paper # PRMU2001-103,NC2001-53
Volume (vol) vol.101
Number (no) 362
Page pp.pp.-
#Pages 8
Date of Issue