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arXiv 2303.07597cs.LGstat.ML
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具有群稀疏正则化器的快速正则化离散最优运输

Fast Regularized Discrete Optimal Transport with Group-Sparse Regularizers

NTT Computer and Data Science Laboratories(NTT计算机与数据科学实验室);NTT Communication Science Laboratories(NTT通信科学实验室)

Yasutoshi Ida, Sekitoshi Kanai, Kazuki Adachi, Atsutoshi Kumagai, Yasuhiro Fujiwara

摘要:

正则化离散最优迁移(OT)是一个强大的工具来衡量两个离散分布之间的距离,已经从两个不同的域上的数据样本构造。虽然它在机器学习中有广泛的应用,但在某些情况下,仅来自一个域的采样数据将具有类标签,例如无监督的领域自适应。在这类问题设置中,经常利用组稀疏正则化器作为正则化项来处理类标签。特别地,它可以通过将具有相同类别标签的数据样本对应到一个组稀疏正则化项来保持数据样本上的标签结构。因此,我们可以测量的距离,同时利用标签信息,通过解决正则化优化问题与基于梯度的算法。然而,当类或数据样本的数量很大时,梯度计算是昂贵的,因为正则化项的数量和它们各自的大小也很大。本文提出了一种快速离散OT与组稀疏正则化。我们的方法基于两个想法。第一个是安全地跳过必须为零的梯度的计算。第二个是有效地提取预期为非零的梯度。我们的方法保证返回与原始方法相同的目标函数值。实验表明,我们的方法是高达8.6倍的速度比原来的方法,而不降低准确性。

英文摘要:

Regularized discrete optimal transport (OT) is a powerful tool to measure the distance between two discrete distributions that have been constructed from data samples on two different domains. While it has a wide range of applications in machine learning, in some cases the sampled data from only one of the domains will have class labels such as unsupervised domain adaptation. In this kind of problem setting, a group-sparse regularizer is frequently leveraged as a regularization term to handle class labels. In particular, it can preserve the label structure on the data samples by corresponding the data samples with the same class label to one group-sparse regularization term. As a result, we can measure the distance while utilizing label information by solving the regularized optimization problem with gradient-based algorithms. However, the gradient computation is expensive when the number of classes or data samples is large because the number of regularization terms and their respective sizes also turn out to be large. This paper proposes fast discrete OT with group-sparse regularizers. Our method is based on two ideas. The first is to safely skip the computations of the gradients that must be zero. The second is to efficiently extract the gradients that are expected to be nonzero. Our method is guaranteed to return the same value of the objective function as that of the original method. Experiments show that our method is up to 8.6 times faster than the original method without degrading accuracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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