MedMix: Specialization-Consistent Federated Sparse MoEs under Modality Heterogeneity Adiba Orzikulova, Dong Min Kim, Jaehong Yoon, and Sung-Ju Lee arXiv preprint, 2026 Paper SNAP: Low-Latency Test-Time Adaptation with Sparse Updates Hyeongheon Cha, Dong Min Kim, Hye Won Chung, Taesik Gong, and Sung-Ju Lee NeurIPS 2025 Website Paper Code