collaborators

10 papers

math.OC2026

Mini-Batch Stochastic Halpern Algorithm for Nonexpansive Fixed Point Problems

Hideaki Iiduka

The Halpern algorithm is a powerful fixed point approximation method for finding the closest point in the fixed point set of a nonexpansive mapping to the initial point. However, i…

math.OC2026

Mini-Batch Stochastic Krasnosel'ski\uı-Mann Algorithm for Nonexpansive Fixed Point Problems

Hideaki Iiduka

The Krasnosel'ski\uı-Mann algorithm is a well-known method for finding fixed points of a nonexpansive mapping with strong theoretical guarantees. However, there are practical larg…

cs.LG2025

Faster Convergence of Riemannian Stochastic Gradient Descent with Increasing Batch Size

Kanata Oowada, Hideaki Iiduka

We theoretically analyzed the convergence behavior of Riemannian stochastic gradient descent (RSGD) and found that using an increasing batch size leads to faster convergence than u…

cs.LG2025

Accelerating SGDM via Learning Rate and Batch Size Schedules: A Lyapunov-Based Analysis

Yuichi Kondo, Hideaki Iiduka

We analyze the convergence behavior of stochastic gradient descent with momentum (SGDM) under dynamic learning-rate and batch-size schedules by introducing a novel and simpler Lyap…

cs.LG2025

Increasing Batch Size Improves Convergence of Stochastic Gradient Descent with Momentum

Keisuke Kamo, Hideaki Iiduka

Stochastic gradient descent with momentum (SGDM), in which a momentum term is added to SGD, has been well studied in both theory and practice. The theoretical studies show that the…

cs.LG2025

Both Asymptotic and Non-Asymptotic Convergence of Quasi-Hyperbolic Momentum using Increasing Batch Size

Kento Imaizumi, Hideaki Iiduka

Momentum methods were originally introduced for their superiority to stochastic gradient descent (SGD) in deterministic settings with convex objective functions. However, despite t…