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Atsutoshi Kumagai

22 accepted papers

2026

Do We Really Need Permutations? Impact of Width Expansion on Linear Mode Connectivity

ICLR 2026poster

Recently, Ainsworth et al. empirically demonstrated that, given two independently trained models, applying a parameter permutation that preserves the input–output behavior allows the two models to be connected by a low-loss linear path. When such a path exists, the models are said to achieve linear…

Cited by 0SourceScholar
2025

Analysis of Linear Mode Connectivity via Permutation-Based Weight Matching: With Insights into Other Permutation Search Methods

ICLR 2025poster

Recently, Ainsworth et al. (2023) showed that using weight matching (WM) to minimize the $L^2$ distance in a permutation search of model parameters effectively identifies permutations that satisfy linear mode connectivity (LMC), where the loss along a linear path between two independently trained mo…

Cited by 0SourcePDFScholar
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

Linear Mode Connectivity between Multiple Models modulo Permutation Symmetries

ICML 2025poster

Ainsworth et al. empirically demonstrated that linear mode connectivity (LMC) can be achieved between two independently trained neural networks (NNs) by applying an appropriate parameter permutation. LMC is satisfied if a linear path with non-increasing test loss exists between the models, suggestin…

2025

Meta-learning Task-specific Regularization Weights for Few-shot Linear Regression

AISTATS 2025poster

We propose a few-shot learning method for linear regression, which learns how to choose regularization weights from multiple tasks with different feature spaces, and uses the knowledge for unseen tasks. Linear regression is ubiquitous in a wide variety of fields. Although regularization weight tunin…

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
2025

Test-time Adaptation for Regression by Subspace Alignment

ICLR 2025poster

This paper investigates test-time adaptation (TTA) for regression, where a regression model pre-trained in a source domain is adapted to an unknown target distribution with unlabeled target data. Although regression is one of the fundamental tasks in machine learning, most of the existing TTA method…

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
2024

Fast Iterative Hard Thresholding Methods with Pruning Gradient Computations

NeurIPS 2024poster

We accelerate the iterative hard thresholding (IHT) method, which finds \(k\) important elements from a parameter vector in a linear regression model. Although the plain IHT repeatedly updates the parameter vector during the optimization, computing gradients is the main bottleneck. Our method safely…

Cited by 0SourcePDFScholar
2024

Zero-Shot Task Adaptation with Relevant Feature Information

AAAI 2024technical

We propose a method to learn prediction models such as classifiers for unseen target tasks where labeled and unlabeled data are absent but a few relevant input features for solving the tasks are given. Although machine learning requires data for training, data are often difficult to collect in pract…

2023

Fast Block Coordinate Descent for Non-Convex Group Regularizations

AISTATS 2023poster

Non-convex sparse regularizations with group structures are useful tools for selecting important feature groups. For optimization with these regularizations, block coordinate descent (BCD) is a standard solver that iteratively updates each parameter group. However, it suffers from high computation c…

Cited by 2SourcePDFScholar
2023

Fast Regularized Discrete Optimal Transport with Group-Sparse Regularizers

AAAI 2023technical

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…

Cited by 2SourcePDFScholar
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

Regularizing Neural Networks with Meta-Learning Generative Models

NeurIPS 2023poster

This paper investigates methods for improving generative data augmentation for deep learning. Generative data augmentation leverages the synthetic samples produced by generative models as an additional dataset for classification with small dataset settings. A key challenge of generative data augment…

Cited by 4SourcePDFScholar
2022

Few-shot Learning for Feature Selection with Hilbert-Schmidt Independence Criterion

NeurIPS 2022accept

We propose a few-shot learning method for feature selection that can select relevant features given a small number of labeled instances. Existing methods require many labeled instances for accurate feature selection. However, sufficient instances are often unavailable. We use labeled instances in mu…

Cited by 11SourcePDFScholar
2022

Meta-ticket: Finding optimal subnetworks for few-shot learning within randomly initialized neural networks

NeurIPS 2022accept

Few-shot learning for neural networks (NNs) is an important problem that aims to train NNs with a few data. The main challenge is how to avoid overfitting since over-parameterized NNs can easily overfit to such small dataset. Previous work (e.g. MAML by Finn et al. 2017) tackles this challenge by me…

2019

Transfer Anomaly Detection by Inferring Latent Domain Representations

NeurIPS 2019poster

We propose a method to improve the anomaly detection performance on target domains by transferring knowledge on related domains. Although anomaly labels are valuable to learn anomaly detectors, they are difficult to obtain due to their rarity. To alleviate this problem, existing methods use anomalou…

Cited by 55SourcePDFScholar