<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bartkowiak, A.</style></author><author><style face="normal" font="default" size="100%">Vassilopoulos, A.</style></author><author><style face="normal" font="default" size="100%">Evelpidou, N.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Choosing data vectors representing a huge data set. Kohonen's SOM applied to the Kefallinia erosion data.</style></title><secondary-title><style face="normal" font="default" size="100%">1st International Conference on Environmental Research &amp; Assessment</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2003</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We consider a large set of data comprising N=3422 data vectors, each containing observations on p=3 variables. We find for these data representative data vectors. We do it by employing the methodology of Kohonen's self-organizing maps. The found representative data vectors are called codebook vectors. In particular we analyze two collections (assemblages) of codebook vectors counting m=275 and m=120 elements. The quantity of the representation is measured by evaluating two errors: the quantization error q1 and the topological error q2. We show for our data that the magnitude of these errors depends on the way the original data were&lt;br&gt;standardized. After a thorough graphical analysis of the results we came to the conclusion that codebook vectors obtained from data standardized by range yield a little better representation as those do which were obtained from data standardized by variance. None of the representations is satisfactory from our point of view.&lt;/p&gt;</style></abstract></record></records></xml>