Part 2: Multilayer perceptron and natural gradient learning

Since the perceptron was developed for learning to classify input patterns, there have been plenty of studies on simple perceptrons and multilayer perceptrons. Despite wide and active studies in theory and applications, multilayer perceptrons still have many unsettled problems such as slow learning speed and overfitting. To find a thorough solution to these problems, it is necessary to consolidate previous studies, and find new directions for uplifting the practical power of multilayer perceptrons. As a first step toward the new stage of studies on multilayer perceptrons, we give short reviews on two interesting and important approaches; one is stochastic approach and the other is geometric approach. We also explain an efficient learning algorithm developed from the statistical and geometrical studies, which is now well known as the natural gradient learning method. Hyeyoung Park, Ph.D.: She is Assistant Professor of Computer Sciences at School of Electrical Engineering and Computer Science of Kyungpook National University in Korea. She received her B.S., M.A. and Ph.D. from Yonsei University of Korea in 1994, 1996, and 2000. She also worked as a research scinetist at Brain Science Institute in RIKEN from 2000 to 2004. Her research insterest is in learning thoeries and pattern recognition as well as statistical data analysis.