Presentation 2007-03-14
Markov and semi-Markov switching of source appearances for non-stationary independent component analysis
Jun-ichiro HIRAYAMA, Shin-ichi MAEDA, Shin ISHII,
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Abstract(in English) Independent Component Analysis (ICA) is currently the most popularly used approach to blind source separation (BSS), the problem of recovering unknown source signals when their mixtures are observed but the actual mixing process is unknown. Real-world signals often have such difficult non-stationarity that each source signal abruptly appears or disappears, which potentially degrades the performance of ordinary ICA especially in noisy situations. To address such non-stationary cases, we have proposed a non-stationary ICA method, called Switching ICA, based on a special type of hidden Markov model. In this article, we present new experimental comparison of our method to some existing methods, with a full treatment of paramter estimation including those for the parameters that have previously been fixed. In simulation experiments using artificial source signals, the proposed method exhibited performance superior to existing methods, especially in the presence of noise. We also propose a simple semi-Markov extension of the original Markov one, to avoid unrealistic assumption implied in the Markov model, that is, the probability of state duration decreases exponentially with its length. The semi-Markov model is demonstrated to be more effective for robust estimation of the source appearance.
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Keyword(in English) independent component analysis / blind source separation / hidden Markov model / hidden semi-Markov model / variational Bayes method
Paper # NC2006-147
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Committee NC
Conference Date 2007/3/7(1days)
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Registration To Neurocomputing (NC)
Language ENG
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Markov and semi-Markov switching of source appearances for non-stationary independent component analysis
Sub Title (in English)
Keyword(1) independent component analysis
Keyword(2) blind source separation
Keyword(3) hidden Markov model
Keyword(4) hidden semi-Markov model
Keyword(5) variational Bayes method
1st Author's Name Jun-ichiro HIRAYAMA
1st Author's Affiliation Graduate School of Information Science, Nara Institute of Science and Technology:Research Fellow of the Japan Society for the Promotion of Science()
2nd Author's Name Shin-ichi MAEDA
2nd Author's Affiliation Graduate School of Information Science, Nara Institute of Science and Technology
3rd Author's Name Shin ISHII
3rd Author's Affiliation Graduate School of Information Science, Nara Institute of Science and Technology
Date 2007-03-14
Paper # NC2006-147
Volume (vol) vol.106
Number (no) 588
Page pp.pp.-
#Pages 6
Date of Issue