INVESTIGATION OF MULTIDIMENSIONAL DATA USING THE INTERACTIVE PATTERN-ANALYSIS SYSTEM ISPAHAN

In 1972, Kanal has enumerated some reasons for the desirability of interactive pattern analysis and classification systems (IPACS). One such system, ISPAHAN, was developed at the Department of Medical Informatics of the Free University in Amsterdam. Although this system is still expanding, it is now in operation. In order to obtain some experience with its properties three data sets, varying in complexity were analysed. Especially the possibility of applying various pattern recognition techniques in succession is shown to lead to an unsupervised classification scheme which may yield essentially the same results as the maximum likelihood decision rule applied to the labelled data set. The results of unsupervised methods are generally influenced by user chosen initial conditions. An objective criterion should therefore be used to compare different configurations. The use of one such criterion, measuring the compactness of the resulting clusters, is demonstrated in this paper. © 1979.