A New Clustering Validity Index for Cluster Analysis Based on a Two-Level SOM

Shu-Ling SHIEH  I-En LIAO  

IEICE TRANSACTIONS on Information and Systems   Vol.E92-D   No.9   pp.1668-1674
Publication Date: 2009/09/01
Online ISSN: 1745-1361
DOI: 10.1587/transinf.E92.D.1668
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Data Mining
self-organizing map,  clustering,  clustering validity index,  

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Self-Organizing Map (SOM) is a powerful tool for the exploratory of clustering methods. Clustering is the most important task in unsupervised learning and clustering validity is a major issue in cluster analysis. In this paper, a new clustering validity index is proposed to generate the clustering result of a two-level SOM. This is performed by using the separation rate of inter-cluster, the relative density of inter-cluster, and the cohesion rate of intra-cluster. The clustering validity index is proposed to find the optimal numbers of clusters and determine which two neighboring clusters can be merged in a hierarchical clustering of a two-level SOM. Experiments show that, the proposed algorithm is able to cluster data more accurately than the classical clustering algorithms which is based on a two-level SOM and is better able to find an optimal number of clusters by maximizing the clustering validity index.