YI Yuki Ichihara Personal academic homepage

Yuki Ichihara

Email / Google Scholar / GitHub

Starting in Aug 2026, I will join MBZUAI as a Ph.D. student, supervised by Junpei Komiyama.

My recent interests include Best-of-N and Minimum Bayes Risk decoding, alignment under multiple objectives, and theoretical questions that help explain practical generation behavior.

Research Interests Reinforcement learning for language models, alignment, decoding, reward design, evaluation, and multi-objective generation.

News

I will join MBZUAI as a Ph.D. student, supervised by Junpei Komiyama.
I joined MBZUAI as a Visiting Student.
Consensus Group Relative Policy Optimization for Text Generation was posted on arXiv.

Selected Publications

  1. Consensus Group Relative Policy Optimization for Text Generation
    Y. Ichihara, Y. Jinnai, K. Ariu, E. Uchibe
    arXiv preprint, 2026
    Paper Code
  2. MO-GRPO: Mitigating Reward Hacking of Group Relative Policy Optimization on Multi-Objective Problems
    Y. Ichihara, Y. Jinnai, T. Morimura, M. Sakamoto, R. Mitsuhashi, E. Uchibe
    arXiv preprint, 2025
    Paper Code
  3. Auto-Weighted Group Relative Preference Optimization for Multi-Objective Text Generation Tasks
    Y. Ichihara, Y. Jinnai
    EMNLP Industry Track, 2025
    Paper Code
  4. Theoretical Guarantees for Minimum Bayes Risk Decoding
    Y. Ichihara, Y. Jinnai, K. Ariu, T. Morimura, E. Uchibe
    ACL, 2025
    Paper
  5. Evaluation of Best-of-N Sampling Strategies for Language Model Alignment
    Y. Ichihara, Y. Jinnai, T. Morimura, K. Abe, K. Ariu, M. Sakamoto, E. Uchibe
    Transactions on Machine Learning Research, 2025
    Paper

Background

Education

MBZUAI Ph.D. (incoming), supervised by Junpei Komiyama
Nara Institute of Science and Technology Ph.D. in Engineering
Nara Institute of Science and Technology M.S. in Engineering
Tokyo University of Science B.S. in Electrical Engineering

Research Experience

MBZUAI Visiting Student
CyberAgent AI Lab Research Intern
ATR Research Assistant
JST SPRING Fellowship Doctoral fellowship