activity
20242026
most citedAnomaly Detection in Double-entry Bookkeeping Data by Federated Learning System with Non-model Sharing Approach

1 citations · 1 across the 10 of their papers we have counts for

collaborators

11 papers

cs.CL2026

FedAlphaEdit: Null-Space-Aligned Merging for Collaborative Knowledge Editing

Sota Sugawara, Yukihiko Okada

Multiple institutions may each hold their own private knowledge edits and wish to integrate them into a single large language model without sharing raw edit requests. Null-space-co…

cs.LG2026

Geometric Data Perturbation with Noisy-Anchor Alignment for Privacy-Preserving Collaborative Learning

Keiyu Nosaka, Yamato Suetake, Yuichi Takano +2

Geometric data perturbation enables one-shot representation sharing for privacy-preserving collaborative learning: each participant applies a secret distance-preserving transformat…

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

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…

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.LG2025

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.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…

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★ 1 cited

Anomaly Detection in Double-entry Bookkeeping Data by Federated Learning System with Non-model Sharing Approach

Sota Mashiko, Yuji Kawamata, Tomoru Nakayama +2

Anomaly detection is crucial in financial auditing, and effective detection requires large volumes of data from multiple organizations. However, journal entry data is highly sensit…

stat.ME2025

Data collaboration for causal inference from limited medical testing and medication data

Tomoru Nakayama, Yuji Kawamata, Akihiro Toyoda +7

Observational studies enable causal inferences when randomized controlled trials (RCTs) are not feasible. However, integrating sensitive medical data across multiple institutions i…

stat.ME2024

Estimation of conditional average treatment effects on distributed confidential data

Yuji Kawamata, Ryoki Motai, Yukihiko Okada +2

The estimation of conditional average treatment effects (CATEs) is an important topic in many scientific fields. CATEs can be estimated with high accuracy if data distributed acros…