TABLE I.

Comparison of properties between CPMs and alternative methods (✓: applicable, ×: inapplicable)

Method	Multiple classifiers	Identify easy/hard	Unlabeled data	Distribution mismatch	Smoothness assumption	Non-parallel hyperplanes	Progressive labeling
Boosting [27]	✓	×	×	×	×	×	×
TW-SVM [37]	✓	×	×	×	×	✓	×
Self-paced learning [39]	×	✓	×	×	×	×	×
RO-SVM [4], [33]	×	✓	×	×	×	×	×
Self-training [46]	×	×	✓	×	×	×	✓
Co-training [6]	✓	×	✓	×	×	×	✓
Lap-SVM [43]	×	×	✓	×	✓	×	×
DAM [21]	✓	×	✓	✓	✓	×	✓
CPM (proposed)	✓	✓	✓	✓	✓	✓	✓