Confidence-weighted Learning for Feature Evolution

Compared with traditional online learning for fixed features, feature evolvable learning usually assumes that features would not vanish or appear in an arbitrary way, while the old features and new features gathered by the hardware devices will disappear and emerge at the same time along with the devices exchanging simultaneously. However, the existing feature evolvable algorithms merely utilize the first-order information of data streams, regardless of the second-order information which explores the correlations between features and significantly improves the classification performance. A confidence-weighted learning for feature evolution (CWFE) algorithm is proposed to solve the aforementioned problem. First, second-order confidence-weighted learning for data streams is introduced to update the prediction model. Next, in order to benefit the learned model, linear mapping during the overlap period is learned to recover the old features. Then, the existing model is updated with the recovered old features, and at the same time, a new predictive model is learned with the new features. Furthermore, two ensemble methods are introduced to utilize these two models. Finally, empirical studies show superior performance over state-of-the-art feature evolvable algorithms. © Copyright 2022, Institute of Software, the Chinese Academy of Sciences. All rights reserved.