An Ensemble Method for Incremental Classification in Stationary and Non-stationary Environments

We present a model based on ensemble of base classifiers, that are combined using weighted majority voting, for the task of incremental classification. Definition of such voting weights becomes even more critical in non-stationary environments where the patterns underlying the observations change over time. Given an instance to classify, we propose to define each voting weight as a function that will take into account the location of an instance to classify in the different class-specific feature spaces and also the prior probability of such classes given the knowledge represented by the classifier as well as its overall performance in learning its training examples. This approach can improve the generalization performance and ability to control the stability/plasticity tradeoff, in stationary and non-stationary environments. Experiments were carried out using several real classification problems already introduced to test incremental algorithms in stationary as well as non-stationary environments.