Top-performing deep architectures are trained on massive amounts of labeled data. In the absence of labeled data for a certain task, domain adaptation often provides an attractive option given that labeled data of similar nature but from a different domain (e.g. synthetic images) are available. Here, we propose a new approach to domain adaptation in deep architectures that can be trained on large amount of labeled data from the source domain and large amount of unlabeled data from the target domain (no labeled target-domain data is necessary). As the training progresses, the approach promotes the emergence of "deep" features that are (i) discriminative for the main learning task on the source domain and (ii) invariant with respect to the shift between the domains. We show that this adaptation behaviour can be achieved in almost any feed-forward model by augmenting it with few standard layers and a simple new gradient reversal layer. The resulting augmented architecture can be trained using standard backpropagation. Overall the whole approach can be implemented with little effort using any of the deep-learning packages.

本论文提出了一种新的深度架构领域适应方法，可通过大量源域标记数据和大量目标域未标记数据的训练而实现。在提出的方法中，深层特征在源域的主要学习任务上是有区分性的，而且对于域之间的变化具有不变性。而通过增加几个标准层和简单的梯度反转层的方法可以实现该适应行为，并且此方法在图像分类实验中表现非常出色。

反向传播无监督域自适应