Ensemble model and algorithm with recalling and forgetting mechanisms for data stream mining

Using ensemble of classifiers on sequential chunks of training instances is a popular strategy for data stream mining with concept drifts. Aiming at the limitations of existing approaches, this paper introduces human recalling and forgetting mechanisms into a data stream mining system, and proposes a memorizing based data stream mining (MDSM) model. The model considers base classifiers as learned knowledge. Through recalling and forgetting mechanism, most useful classifiers in the past will be reserved in a memory repository, which improves the stability under random concept drifts. The best classifiers for the current data chunk are selected for prediction, which achieves high adaptability for different concept drifts. Based on MSDM, the paper puts forward a new algorithm MAE (memorizing based adaptive ensemble). MAE uses Ebbinghaus forgetting curve as forgetting mechanism and adopts ensemble pruning to emulate the recalling mechanism. Compared with four traditional data stream mining approaches, the results show that MAE achieves high and stable accuracy with moderate training time. The results also proved that MAE has good adaptability for different kinds of concept drifts, especially for the applications with recurring or complex concept drifts. © Copyright 2015, Institute of Software, the Chinese Academy of Sciences. All rights reserved.