activity
20242026
collaborators

5 papers

cs.LG2026

Offline Contextual Bandits in the Presence of New Actions

Ren Kishimoto, Tatsuhiro Shimizu, Kazuki Kawamura +6

Automated decision-making algorithms drive applications such as recommendation systems and search engines. These algorithms often rely on off-policy contextual bandits or off-polic…

cs.CL2026

PROTEA: Offline Evaluation and Iterative Refinement for Multi-Agent LLM Workflows

Kazuki Kawamura, Satoshi Waki, Kei Tateno

Multi-agent LLM workflows -- systems composed of multiple role-specific LLM calls -- often outperform single-prompt baselines, but they remain difficult to debug and refine. Failur…

cs.LG2026

Off-Policy Evaluation for Ranking Policies under Deterministic Logging Policies

Koichi Tanaka, Kazuki Kawamura, Takanori Muroi +6

Off-Policy Evaluation (OPE) is an important practical problem in algorithmic ranking systems, where the goal is to estimate the expected performance of a new ranking policy using o…

cs.IR2025

Counterfactual Reciprocal Recommender Systems for User-to-User Matching

Kazuki Kawamura, Takuma Udagawa, Kei Tateno

Reciprocal recommender systems (RRS) in dating, gaming, and talent platforms require mutual acceptance for a match. Logged data, however, over-represents popular profiles due to pa…

cs.IR2024

Parallel and Mini-Batch Stable Matching for Large-Scale Reciprocal Recommender Systems

Kento Nakada, Kazuki Kawamura, Ryosuke Furukawa

Reciprocal recommender systems (RRSs) are crucial in online two-sided matching platforms, such as online job or dating markets, as they need to consider the preferences of both sid…