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Hiroshi Takahashi

7 accepted papers

2025

Importance-weighted Positive-unlabeled Learning for Distribution Shift Adaptation

AISTATS 2025oral

Positive and unlabeled (PU) learning is a fundamental task in many applications, which trains a binary classifier from only PU data. Existing PU learning methods typically assume that training and test distributions are identical. However, this assumption is often violated due to distribution shifts…

Cited by 0SourceScholar
2025

Positive-Unlabeled Diffusion Models for Preventing Sensitive Data Generation

ICLR 2025poster

Diffusion models are powerful generative models but often generate sensitive data that are unwanted by users, mainly because the unlabeled training data frequently contain such sensitive data. Since labeling all sensitive data in the large-scale unlabeled training data is impractical, we address thi…

Cited by 0SourcePDFScholar
2025

Positive-unlabeled AUC Maximization under Covariate Shift

ICML 2025poster

Maximizing the area under the receiver operating characteristic curve (AUC) is a standard approach to imbalanced binary classification tasks. Existing AUC maximization methods typically assume that training and test distributions are identical. However, this assumption is often violated due to {\it…

Cited by 1SourcePDFScholar
2024

AUC Maximization under Positive Distribution Shift

NeurIPS 2024poster

Maximizing the area under the receiver operating characteristic curve (AUC) is a popular approach to imbalanced binary classification problems. Existing AUC maximization methods usually assume that training and test distributions are identical. However, this assumption is often violated in practice…

Cited by 0SourcePDFScholar
2023

Meta-learning for Robust Anomaly Detection

AISTATS 2023poster

We propose a meta-learning method to improve the anomaly detection performance on unseen target tasks that have only unlabeled data. Existing meta-learning methods for anomaly detection have shown remarkable performance but require labeled data in target tasks. Although they can treat unlabeled data…

2023

One-vs-the-Rest Loss to Focus on Important Samples in Adversarial Training

ICML 2023poster

This paper proposes a new loss function for adversarial training. Since adversarial training has difficulties, e.g., necessity of high model capacity, focusing on important data points by weighting cross-entropy loss has attracted much attention. However, they are vulnerable to sophisticated attacks…

Cited by 12SourcePDFScholar