Deep Ensemble Learning by Diverse Knowledge Distillation for Fine-Grained Object Classification

Ensemble of networks with bidirectional knowledge distillation does not significantly improve on the performance of ensemble of networks without bidirectional knowledge distillation. We think that this is because there is a relationship between the knowledge in knowledge distillation and the individuality of networks in the ensemble. In this paper, we propose a knowledge distillation for ensemble by optimizing the elements of knowledge distillation as hyperparameters. The proposed method uses graphs to represent diverse knowledge distillations. It automatically designs the knowledge distillation for the optimal ensemble by optimizing the graph structure to maximize the ensemble accuracy. Graph optimization and evaluation experiments using Stanford Dogs, Stanford Cars, CUB-200-2011, CIFAR-10, and CIFAR-100 show that the proposed method achieves higher ensemble accuracy than conventional ensembles.