Adversarial domain adaptation using contrastive learning

In recent research, problems with biased datasets or domain shift have presented challenges to the practical applications of deep learning methods. In this paper, we propose a simple method using adversarial learning combined with contrastive learning and domain adaptation to solve the domain-shift problem. Because domain shift is caused by differences in the distribution of data across domains, different approaches have been proposed to resolve this by rendering the data distributions closer through adversarial training. Contrastive learning is a method of acquiring valid feature representations for downstream tasks. By combining these approaches, we aim to achieve better domain adaptation. The proposed method is simple and intuitive. By introducing a domain discriminator into SimCLR, which is a typical contrastive learning model, and training it in an adversarial manner, the feature vectors of the source and target domains are rendered closer to acquire domain-invariant features. The proposed approach facilitates high-performance pretraining without labels and demonstrates a significant improvement in accuracy in comparison to standard benchmark methods, including conventional supervised models and SimCLR.