6Chicco G, Napoli R, Piglione F. Comparisons among clustering techniques for electricity customer classification[J]. IEEE Transactions on Power Systems, 2006, 21(2): 933-940.
7Pakhira M K, Bandyopadhyay S, Maulik U. Validity indexfor crisp and fuzzy clusters[J]. Pattern Recognition, 2004, 37(3): 487-501.
8Milligan G, Cooper M. An examination of procedures for determining the number of clusters in a data set [J]. Psychometrika, 1985, 50(2): 159-179.
9Kim M, Ramakrishna R S. New indices for cluster validity assessment[J]. Pattern Recognition Letters, 2005, 26(15): 2353-2363.
10Davies D L, Bouldin D W. A cluster separation measure[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1979, 1(2): 224-227.
