MASS-DPO: Multi-negative Active Sample Selection for Direct Policy Optimization. - Rohan Surana; Xintong Li 001; Sheldon Yu; Yiran Jenny Shen; Chuhan Wang; Tong Yu 001; Prithviraj Ammanabrolu; Jingbo Shang; Julian J. McAuley; Xiaojun Wu 001 (CoRR, 2026)