Think Wise, Collaborate Effectively: A Rationale-Aware LLM-Based Recommender with Reinforcement Learning from Collaborative Signals. - Chung Park; Taesan Kim; Hyeongjun Yun; Dongjoon Hong; Junui Hong; Kijung Park; Mincheol Cho; Minsung Choi; Jihwan Seok; Jaegul Choo (AAAI, 2026)