collaborators

18 papers

math.OC2026

Asymmetric Perturbation in Solving Bilinear Saddle-Point Optimization

Kenshi Abe, Mitsuki Sakamoto, Kaito Ariu +1

This paper proposes asymmetric perturbation, where only one player's payoff function is perturbed, for solving bilinear saddle-point optimization problems, commonly arising in mini…

stat.ML2026

Policy Testing in Markov Decision Processes

Kaito Ariu, Po-An Wang, Alexandre Proutiere +1

We study the policy testing problem in discounted Markov decision processes (MDPs) in the fixed-confidence setting under a generative model with static sampling. The goal is to dec…

cs.LG2026

Linear Convergence in Games with Delayed Feedback via Extra Prediction

Yuma Fujimoto, Kenshi Abe, Kaito Ariu

Feedback delays are inevitable in real-world multi-agent learning. They are known to severely degrade performance, and the convergence rate under delayed feedback is still unclear,…

cs.GT2026

Time-Varyingness in Auction Breaks Revenue Equivalence

Yuma Fujimoto, Kaito Ariu, Kenshi Abe

Auction is applied for trade with various mechanisms. A simple but practical question is which mechanism, typically first-price or second-price auctions, is preferred from the pers…

cs.LG2026

Consensus Group Relative Policy Optimization for Text Generation

Yuki Ichihara, Yuu Jinnai, Kaito Ariu +1

Many strong decoding methods for text generation follow a sample-and-rerank paradigm: they draw multiple candidates, score each under a utility (reward) function using consensus ac…

cs.RO2026

What you reward is what you learn: Comparing rewards for online speech policy optimization in public HRI

Sichao Song, Yuki Okafuji, Kaito Ariu +1

Designing policies that are both efficient and acceptable for conversational service robots in open and diverse environments is non-trivial. Unlike fixed, hand-tuned parameters, on…