Noise-robust oversampling for imbalanced data classification

Abstract

The class imbalance problem is characterized by an unequal data distribution in which majority classes have a greater number of data samples than minority classes. Oversampling methods generate samples for minority classes to balance the data distribution. However, the generated minority samples may overlap with majority samples, resulting in noise. In this paper, we propose a noise-robust oversampling algorithm for mixed-type and multi-class imbalanced data. Our proposed noise-robust designs include an algorithm to eliminate noise within clusters of data samples, adaptive embedding to generate samples safely, and a safe boundary for enlarging class boundaries. The heterogeneous distance metric and adapted decomposition strategy render our noise-robust algorithm suitable for mixed-type and multi-class imbalanced data. Experimental results on 20 benchmark datasets demonstrate the effectiveness of the proposed algorithm.