collaborators

9 papers

cs.LG2026

Single-Round Clustered Federated Learning via Data Collaboration Analysis for Non-IID Data

Sota Sugawara, Yuji Kawamata, Akihiro Toyoda +2

Federated Learning (FL) enables distributed learning across multiple clients without sharing raw data. When statistical heterogeneity across clients is severe, Clustered Federated…

cs.LG2026

Covariance-Based Structural Equation Modeling in Small-Sample Settings with

Hiroki Hasegawa, Aoba Tamura, Yukihiko Okada

Factor-based Structural Equation Modeling (SEM) relies on likelihood-based estimation assuming a nonsingular sample covariance matrix, which breaks down in small-sample settings wi…

cs.LG2026

A new type of federated clustering: A non-model-sharing approach

Yuji Kawamata, Kaoru Kamijo, Masateru Kihira +5

In recent years, the growing need to leverage sensitive data across institutions has led to increased attention on federated learning (FL), a decentralized machine learning paradig…

cs.LG2026

Interaction Tensor SHAP

Hiroki Hasegawa, Yukihiko Okada

This study proposes Interaction Tensor SHAP (IT-SHAP), a tensor algebraic formulation of the Shapley Taylor Interaction Index (STII) that makes its computational structure explicit…

stat.ME2025

Estimating Covariate-balanced Survival Curve in Distributed Data Environment using Data Collaboration Quasi-Experiment

Akihiro Toyoda, Yuji Kawamata, Tomoru Nakayama +3

The sharing of patient-level data necessary for covariate-adjusted survival analysis between medical institutions is difficult due to privacy protection restrictions. We propose a…

cs.LG2025

A Robust and Non-Iterative Tensor Decomposition Method with Automatic Thresholding

Hiroki Hasegawa, Yukihiko Okada

Recent advances in IoT and biometric sensing technologies have led to the generation of massive and high-dimensional tensor data, yet achieving accurate and efficient low-rank appr…