In this paper, we study the problem of legal domain adaptation problem from
an imbalanced source domain to a partial target domain. The task aims to
improve legal judgment predictions for non-professional fact descriptions. We
formulate this task as a partial-and-imbalanced domain adaptation problem.
Though deep domain adaptation has achieved cutting-edge performance in many
unsupervised domain adaptation tasks. However, due to the negative transfer of
samples in non-shared classes, it is hard for current domain adaptation model
to solve the partial-and-imbalanced transfer problem. In this work, we explore
large-scale non-shared but related classes data in the source domain with a
hierarchy weighting adaptation to tackle this limitation. We propose to embed a
novel pArtial Imbalanced Domain Adaptation technique (AIDA) in the deep
learning model, which can jointly borrow sibling knowledge from non-shared
classes to shared classes in the source domain and further transfer the shared
classes knowledge from the source domain to the target domain. Experimental
results show that our model outperforms the state-of-the-art algorithms.

本文研究了从不平衡的源领域到部分目标领域的法律领域适应性问题，该领域的任务是提高针对非专业事实描述的法律判断预测。我们将此任务描述为部分和不平衡的领域适应问题，并探索了在源域中大规模的非共享类相关数据，通过分级加权适应来解决这个限制。我们在深度学习模型中嵌入了一种新的部分不平衡领域适应技术（AIDA），它可以共同借用非共享类的兄弟知识来处理源领域中的共享类并进一步将共享类的知识从源领域转移到目标领域。实验结果表明，我们的模型优于现有的算法。