A top-down approach for density-based clustering using multidimensional indexes

Abstract

Clustering on large databases has been studied actively as all increasing number of applications involve huge amount of data. In this paper, we propose all efficient top-down approach for density-based clustering, which is based on the density information stored in index nodes of a multidimensional index. We first provide a formal definition of the cluster based on the concept of region contrast partition. Based on this notion, we propose a novel top-down clustering algorithm, which improves the efficiency through branch-and-bound pruning. For this pruning, we present a technique for determining the bounds based oil sparse and dense internal regions and formally prove the correctness of the bounds. Experimental results show that the proposed method reduces the elapsed time by up to 96 times compared with that of BIRCH, which is a well-known clustering method. The results also show that the performance improvement becomes more marked as the size of the database increases. (C) 2003 Elsevier Inc. All rights reserved.