An Ensemble Learning Model Based on Three-Way Decision for Concept Drift Adaptation

The ensemble learning model can effectively detect drift and utilize diversity to improve the performance of adapting to drift. However, local concept drift can occur in different types at different time points, causing basic learners are difficult to distinguish the drift of local boundaries, and the drift range is difficult to determine. Thus, the ensemble learning model to adapt local concept drifts is still challenging problem. Moreover, there are often differences in decision boundaries after drift adaptation, and employing overall diversity measurement is inappropriate. To address these two issues, this paper proposes a novel ensemble learning model called instanceweighted ensemble learning based on the three-way decision (IWE-TWD). In IWE-TWD, a divide-and-conquer strategy is employed to handle uncertain drift and to select base learners; Density clustering dynamically constructs density regions to lock drift range; Three-way decision is adopted to estimate whether the region distribution changes, and the instance is weighted with the probability of region distribution change; The diversities between base learners are determined with three-way decision also. Experimental results show that IWE-TWD has better performance than the state-of-the-art models in data stream classification on ten synthetic data sets and seven real-world data sets.