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Kochi Pascual-Marqui

Fakultäten » Medizinische Fakultät » Psychiatrische Universitätsklinik » Psychiatrie, Psychotherapie und Psychosomatik, Klinik für » Prof. Dr. Daniel Hell (emeritiert) » Kochi Pascual-Marqui

Completed research project

Title / Titel New artificial neural networks for improved probability density estimation and self organizing maps
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung A new self-organizing map algorithm is being developed [1]. Unlike the well-known method of Kohonen [2], the new algorithm corresponds to the optimization of an unambiguously defined cost function. It consists of a modified version of the widely used fuzzy c-means functional, where the code vectors are distributed on a regular low dimensional grid, and a penalization term is added in order to guarantee a smooth distribution for the values of the code vectors on the grid. The mapping properties of the new method are similar to those of Kohonen’s algorithm. Unlike the method of Kohonen, the advantage of our new method is that there is complete control over the mapping process. A second form of self-organizing map is also being developed, based on a “smoothly distributed kernel density estimator”. Preliminary results show that this method is superior to the classical method of Kohonen in two main aspects: better mapping, and a better estimate of the probability density. The importance of these results is that the new mapping techniques will allow improved pattern recognition in diverse applications (cluster analysis, discriminant analysis, etc).
Publications / Publikationen Pascual-Marqui RD. Pascual-Montano AD. Kochi K. Carazo JM. Smoothly Distributed Fuzzy c-Means: a New Self-Organizing Map. In press. To be published in 2001. Pattern Recognition.
T. Kohonen, Self-organizing Maps, Springer Verlag, Berlin, 1995.
Keywords / Suchbegriffe Self-organizing maps; Fuzzy clustering; Fuzzy c-means; Regularization; Smoothing; Kernel density
Project leadership and contacts /
Projektleitung und Kontakte
Kieko Kochi (Project Leader) kieko@access.uzh.ch
Roberto D. Pascual-Marqui (Project Leader) pascualm@key.uzh.ch
Jose M. Carazo carazo@cnb.uam.es
Other links to external web pages http://www.cnb.uam.es
Funding source(s) /
Unterstützt durch
Others
KEY Institute
Duration of Project / Projektdauer Jan 2000 to Dec 2001