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arXiv 2409.19600cs.LGcs.AIstat.ML
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一种面向增广类别部分标签学习的无偏风险估计器

An Unbiased Risk Estimator for Partial Label Learning with Augmented Classes

College of Computer Science, Chongqing University(重庆大学计算机学院)

Jiayu Hu, Senlin Shu, Beibei Li, Tao Xiang, Zhongshi He

AI总结:

本文针对增广类别部分标签学习(PLLAC)问题,提出一种具有理论保证的无偏风险估计器,通过从未标注数据中区分已知类别分布来估计增广类别分布,并引入风险惩罚正则化项缓解过拟合,在多个数据集上验证了有效性。

摘要:

部分标签学习(PLL)是一种典型的弱监督学习任务,其假设每个训练实例被标注为一组候选标签,其中包含真实标签。近年来,PLL方法采用基于识别的消歧策略来减轻假阳性标签的影响,并取得了良好的性能。然而,这些方法要求测试集中的所有类别都已在训练集中出现,忽略了实际应用中新类别会不断涌现的事实。为了解决这一问题,本文聚焦于增广类别部分标签学习(PLLAC)问题,即一个或多个增广类别在训练阶段不可见,但在推理阶段出现。具体而言,我们提出了一种具有理论保证的无偏风险估计器用于PLLAC,该估计器通过从未标注数据中区分已知类别的分布来估计增广类别的分布,并且可以配备任意PLL损失函数。此外,我们对该估计器的估计误差界进行了理论分析,保证了当训练数据数量趋于无穷时,经验风险最小化器收敛到真实风险最小化器。进一步地,我们在优化目标中加入了一个风险惩罚正则化项,以减轻由负经验风险引起的过拟合问题的影响。在基准数据集、UCI数据集和真实世界数据集上的大量实验证明了所提方法的有效性。

英文摘要:

Partial Label Learning (PLL) is a typical weakly supervised learning task, which assumes each training instance is annotated with a set of candidate labels containing the ground-truth label. Recent PLL methods adopt identification-based disambiguation to alleviate the influence of false positive labels and achieve promising performance. However, they require all classes in the test set to have appeared in the training set, ignoring the fact that new classes will keep emerging in real applications. To address this issue, in this paper, we focus on the problem of Partial Label Learning with Augmented Class (PLLAC), where one or more augmented classes are not visible in the training stage but appear in the inference stage. Specifically, we propose an unbiased risk estimator with theoretical guarantees for PLLAC, which estimates the distribution of augmented classes by differentiating the distribution of known classes from unlabeled data and can be equipped with arbitrary PLL loss functions. Besides, we provide a theoretical analysis of the estimation error bound of the estimator, which guarantees the convergence of the empirical risk minimizer to the true risk minimizer as the number of training data tends to infinity. Furthermore, we add a risk-penalty regularization term in the optimization objective to alleviate the influence of the over-fitting issue caused by negative empirical risk. Extensive experiments on benchmark, UCI and real-world datasets demonstrate the effectiveness of the proposed approach.

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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