Recurrent drifts: Aapplying fuzzy logic to concept similarity function

Recurrent drift, as a specific type of concept drift, is characterised by the appearance of previously seen concepts. Therefore, in those cases the learning process could be saved or at least minimized by applying an already trained classification model. In this paper we propose Fuzzy-Rec, a framework that is able to deal with recurrent concept drifts by means of a repository of classification models and a similarity function. Fuzzy logic is used in the framework to implement the similarity function needed to compare different classification models. This is a crucial aspect when dealing with drift recurrence, as long as some measure must be implemented to determine which model better fits a previously seen context. As it can be seen in the experimentation results of this paper, this fuzzy similarity function provides excellent results both in synthetic and real datasets. As a conclusion, we can state that the introduction of fuzzy logic comparisons between models could lead to a better efficient reuse of previously seen concepts, saving computational resources by applying not just equal models, but also similar ones.