I am a CS PhD candidate at Tokyo Institute of Technology, advised by Naoaki Okazaki. My expected graduation date is March 2026. Currently, I am visiting the UPenn NLP, hosted by Chris Callison-Burch. I also work with Preslav Nakov from MBZUAI.

I work on AI safety, specifically improving the safety of large language models (LLMs) from various perspectives, including:

• Detecting texts generated by LLMs, particularly in increasing its robustness against adversarial attacks in the wild, like OUTFOX (AAAI 2024);How You Prompt Matters (Findings of EMNLP 2024)
• Enhancing LLM-as-a-judge to be more reliable by mitigating its evaluation bias, like Likelihood-based mitigation (Findings of ACL 2024)

In addition, I have broad interests in AI safety, including jailbreak and safe alignment.

📢 I am actively looking for research internships starting in (Summer | Fall | Winter) 2025.

• Personal Website: sites.google.com/view/ryutokoike/
• Twitter: @sponddd
• email: my_first_name.my_last_name[at]nlp.c.titech.ac.jp