collaborators

6 papers

cs.LG2026

MARS: Margin and Semantic-Aware Data Augmentation for Reward Modeling

Payel Bhattacharjee, Osvaldo Simeone, Ravi Tandon

Reward modeling is central to RLHF, RLAIF, and PPO-based alignment, but its reliability is often limited by scarce and heterogeneous human preference data. In this paper, we introd…

cs.CR2026

Learning to Diagnose Privately: DP-Powered LLMs for Radiology Report Classification

Payel Bhattacharjee, Fengwei Tian, Geoffrey D. Rubin +5

Large Language Models (LLMs) are increasingly adopted across domains such as education, healthcare, and finance. In healthcare, LLMs support tasks including disease diagnosis, abno…

cs.LG2026

Improving Epidemic Analyses with Privacy-Preserving Integration of Sensitive Data

Zihan Guan, Zhiyuan Zhao, Fengwei Tian +5

Epidemic analyses increasingly rely on heterogeneous datasets, many of which are sensitive and require strong privacy protection. Although differential privacy (DP) has become a st…

cs.LG2026

STAMP: Selective Task-Aware Mechanism for Text Privacy

Fengwei Tian, Payel Bhattacharjee, Heidi Hanson +3

We present STAMP (Selective Task-Aware Mechanism for Text Privacy), a new framework for task-aware text privatization that achieves an improved privacy-utility trade-off. STAMP sel…

cs.LG2025

PROPS: Progressively Private Self-alignment of Large Language Models

Noel Teku, Fengwei Tian, Payel Bhattacharjee +3

Alignment is a key step in developing Large Language Models (LLMs) using human feedback to ensure adherence to human values and societal norms. Dependence on human feedback raises…

cs.LG2025

Conformal Sparsification for Bandwidth-Efficient Edge-Cloud Speculative Decoding

Payel Bhattacharjee, Fengwei Tian, Meiyu Zhong +3

Edge-cloud speculative decoding (SD) accelerates inference by having a cloud-based large language model (LLM) that verifies draft tokens generated by a resource-constrained small l…