Density Harmonized Gradient Descent Online Active Learning for Imbalanced Data Streams
摘要
In practical applications, data stream classification faces significant challenges, such as the high cost of data labeling and class imbalance. The former is time-consuming and labor-intensive, while the latter may lead online learning models to favor majority class samples, resulting in incorrect decisions for minority class samples. To address these issues, this paper proposes Density Harmonized Gradient Descent Online Active Learning (DHGDOAL). This method first computes the local density factor of samples based on a sliding window and prioritizes instances located in high-density regions for labeling, thereby annotating valuable samples with a limited query budget. Second, to avoid the model from exhibiting a bias towards the majority class during update, we introduce a gradient harmonization mechanism. Finally, experimental results show that DHGDOAL has high performance in terms of accuracy, AUC, F1-score, and G-MEANS when dealing with imbalanced data streams under a limited budget.