activity
20192026
most citedMean-Variance Analysis in Bayesian Optimization under Uncertainty

7 citations · 25 across the 14 of their papers we have counts for

collaborators

16 papers

stat.ML2026

Improved Regret Analysis for Parallel Gaussian Process Bandit Optimization

Shion Takeno, Shogo Iwazaki

This paper studies the regret analysis for parallel Gaussian process (GP) bandit optimization. The known regret upper bounds for the widely used GP batched upper confidence bound a…

cs.LG2026

Nearly Optimal Algorithms for Adversarial Kernelized Bandits

Shogo Iwazaki

This paper studies kernelized bandits (also known as Gaussian process bandits) in an adversarial environment, where the reward functions in a known reproducing kernel Hilbert space…

stat.ML2026

On Regret Bounds of Thompson Sampling for Bayesian Optimization

Shion Takeno, Shogo Iwazaki

We study a widely used Bayesian optimization method, Gaussian process Thompson sampling (GP-TS), under the assumption that the objective function is a sample path from a GP. Compar…

cs.LG2026

Tighter Regret Lower Bound for Gaussian Process Bandits with Squared Exponential Kernel in Hypersphere

Shogo Iwazaki

We study an algorithm-independent, worst-case lower bound for the Gaussian process (GP) bandit problem in the frequentist setting, where the reward function is fixed and has a boun…

cs.LG2025

Improved Regret Bounds for Gaussian Process Upper Confidence Bound in Bayesian Optimization

Shogo Iwazaki

This paper addresses the Bayesian optimization problem (also referred to as the Bayesian setting of the Gaussian process bandit), where the learner seeks to minimize the regret und…

stat.ML2025

High-dimensional Nonparametric Contextual Bandit Problem

Shogo Iwazaki, Junpei Komiyama, Masaaki Imaizumi

We consider the kernelized contextual bandit problem with a large feature space. This problem involves arms, and the goal of the forecaster is to maximize the cumulative reward…

stat.ML2025

Dose-finding design based on level set estimation in phase I cancer clinical trials

Keiichiro Seno, Kota Matsui, Shogo Iwazaki +3

The primary objective of phase I cancer clinical trials is to evaluate the safety of a new experimental treatment and to find the maximum tolerated dose (MTD). We show that the MTD…

cs.LG2025

Improved Regret Analysis in Gaussian Process Bandits: Optimality for Noiseless Reward, RKHS norm, and Non-Stationary Variance

Shogo Iwazaki, Shion Takeno

We study the Gaussian process (GP) bandit problem, whose goal is to minimize regret under an unknown reward function lying in some reproducing kernel Hilbert space (RKHS). The maxi…

cs.LG2025

Gaussian Process Upper Confidence Bound Achieves Nearly-Optimal Regret in Noise-Free Gaussian Process Bandits

Shogo Iwazaki

We study the noise-free Gaussian Process (GP) bandits problem, in which the learner seeks to minimize regret through noise-free observations of the black-box objective function lyi…

cs.LG2024

Near-Optimal Algorithm for Non-Stationary Kernelized Bandits

Shogo Iwazaki, Shion Takeno

This paper studies a non-stationary kernelized bandit (KB) problem, also called time-varying Bayesian optimization, where one seeks to minimize the regret under an unknown reward f…

stat.ML2021★ 6 cited

Bayesian Optimization for Cascade-type Multi-stage Processes

Shunya Kusakawa, Shion Takeno, Yu Inatsu +6

Complex processes in science and engineering are often formulated as multistage decision-making problems. In this paper, we consider a type of multistage decision-making process ca…

stat.ML2021★ 1 cited

Active learning for distributionally robust level-set estimation

Yu Inatsu, Shogo Iwazaki, Ichiro Takeuchi

Many cases exist in which a black-box function with high evaluation cost depends on two types of variables and , where is a controllable \emph{design} va…

stat.ML2020★ 6 cited

Quantifying Statistical Significance of Neural Network-based Image Segmentation by Selective Inference

Vo Nguyen Le Duy, Shogo Iwazaki, Ichiro Takeuchi

Although a vast body of literature relates to image segmentation methods that use deep neural networks (DNNs), less attention has been paid to assessing the statistical reliability…

stat.ML2020★ 7 cited

Mean-Variance Analysis in Bayesian Optimization under Uncertainty

Shogo Iwazaki, Yu Inatsu, Ichiro Takeuchi

We consider active learning (AL) in an uncertain environment in which trade-off between multiple risk measures need to be considered. As an AL problem in such an uncertain environm…

stat.ML2020★ 2 cited

Bayesian Quadrature Optimization for Probability Threshold Robustness Measure

Shogo Iwazaki, Yu Inatsu, Ichiro Takeuchi

In many product development problems, the performance of the product is governed by two types of parameters called design parameter and environmental parameter. While the former is…

stat.ML2019★ 3 cited

Bayesian Experimental Design for Finding Reliable Level Set under Input Uncertainty

Shogo Iwazaki, Yu Inatsu, Ichiro Takeuchi

In the manufacturing industry, it is often necessary to repeat expensive operational testing of machine in order to identify the range of input conditions under which the machine o…