首页|局部判别损失无监督域适应方法

局部判别损失无监督域适应方法

扫码查看
在无监督域适应任务中,源域和目标域的分布不同,源域数据标签已知,但是目标域的数据标签未知。最大平均差异MMD是一种具有代表性的分布度量方法,广泛应用于源域与 目标域之间的分布差异度量。然而,MMD度量及其变种方法通常忽略了样本的类内紧凑性和类间可分离性,降低了特征表达的可判别性。因此,提出局部判别损失无监督域适应方法,从2个方面提升域适应方法的判别能力:(1)重新设计MMD度量方法的权重,解决类别不均衡问题,使难对齐类别在域间分布上保持一致;(2)探索局部对比损失,平衡正样本对和负样本对之间的关系,从而学习到更好的判别性特征。结合域间损失和类间损失,可使同一类样本靠近,不同类样本之间远离。该方法简单有效,即插即用,可扩展至注意力机制的网络结构上。在多个域适应数据集上,该方法的有效性均得到了验证。
A focally discriminative loss for unsupervised domain adaptation method
The maximum mean discrepancy(MMD),as a representative distribution metric between source domain and target domain,has been widely applied in unsupervised domain adaptation(UDA),where both domains follow different distributions,and the labels from source domain are merely availa-ble.However,MMD and its class-wise variants possibly ignore the intra-class compactness and inter-class separability,thus reducing discriminability of feature representation.This paper proposes a focally discriminative loss for unsupervised domain adaptation.This method endeavors to improve the discrimi-native ability of MMD from two aspects:(1)the weights are re-designed for MMD in order to align the distribution of relatively hard classes across domains;(2)a focally contrastive loss is explored to tradeoff the positive sample pairs and negative ones for better discrimination.The integration of both losses can not only make the intra-class features close,but also push away the inter-class features far from each other.Moreover,the improved loss is simple yet effective,and it can be extended to the net-work structure of the attention mechanism.Experiments on several domain adaptation datasets verify the effectiveness of the proposed method.

unsupervised domain adaptationweighted maximum mean discrepancyfocally contras-tive lossattention mechanism

王姗姗、汪梦竹、骆志刚

展开 >

安徽大学计算智能与信号处理教育部重点实验室,安徽合肥 230039

国防科技大学计算机学院并行与分布计算重点实验室,湖南长沙 410073

无监督域适应 基于类的最大平均差异 局部对比损失 注意力机制

国家自然科学基金

62106003

2024

计算机工程与科学
国防科学技术大学计算机学院

计算机工程与科学

CSTPCD北大核心
影响因子:0.787
ISSN:1007-130X
年,卷(期):2024.46(1)
  • 45