Fig. 6. Importance of designed data enhancement, hard sample mining, and diverse data learning.

a The ablation experimental results about the designed three learning strategies of data enhancement, hard sample mining, and diverse data learning on the HR model. We used these learning strategies to train a series of control models step by step, and gave the classification accuracies on the test sets of groups A–F. b AUC-ROC comparison of the original, enhanced, mined, baseline, and HR models on groups E and F.