activity
20242026
collaborators

5 papers

cs.LG2026

Understanding Head Geometry and Dynamics in Federated Regression through a Natural Solution Selection Rule: An Unconstrained Feature Model Analysis

Chuang Ma, Tomoyuki Obuchi

In federated averaging, local objectives can admit multiple optimal heads, making the aggregate depend on which heads clients return. We study this ambiguity in federated multivari…

stat.ML2025

Perfect reconstruction of sparse signals using nonconvexity control and one-step RSB message passing

Xiaosi Gu, Ayaka Sakata, Tomoyuki Obuchi

We consider sparse signal reconstruction via minimization of the smoothly clipped absolute deviation (SCAD) penalty, and develop one-step replica-symmetry-breaking (1RSB) extension…

stat.ML2025

Graphical model for factorization and completion of relatively high rank tensors by sparse sampling

Angelo Giorgio Cavaliere, Riki Nagasawa, Shuta Yokoi +2

We consider tensor factorizations based on sparse measurements of the components of relatively high rank tensors. The measurements are designed in a way that the underlying graph o…

cs.LG2024

Analysis of High-dimensional Gaussian Labeled-unlabeled Mixture Model via Message-passing Algorithm

Xiaosi Gu, Tomoyuki Obuchi

Semi-supervised learning (SSL) is a machine learning methodology that leverages unlabeled data in conjunction with a limited amount of labeled data. Although SSL has been applied i…

stat.ML2024

Transfer Learning in Regularized Regression: Hyperparameter Selection Strategy based on Sharp Asymptotic Analysis

Koki Okajima, Tomoyuki Obuchi

Transfer learning techniques aim to leverage information from multiple related datasets to enhance prediction quality against a target dataset. Such methods have been adopted in th…