collaborators

7 papers

cs.LG2026

Distributionally Robust Token Optimization in RLHF

Yeping Jin, Jiaming Hu, Ioannis Ch. Paschalidis

Large Language Models (LLMs) tend to respond correctly to prompts that align well with the data they were trained and fine-tuned on. Yet, small shifts in wording, format, or langua…

cs.LG2026

Towards General Preference Alignment: Diffusion Models at Nash Equilibrium

Jiaming Hu, Jiamu Bai, Haoyu Wang +2

Reinforcement learning from human feedback (RLHF) has been popular for aligning text-to-image (T2I) diffusion models with human preferences. As a mainstream branch of RLHF, Direct…

cs.LG2026

Bridging the Gap Between Average and Discounted TD Learning

Haoxing Tian, Zaiwei Chen, Ioannis Ch. Paschalidis +1

The analysis of Temporal Difference (TD) learning in the average-reward setting faces notable theoretical difficulties because the Bellman operator is not contractive with respect…

cs.AI2026

Scaling In-Context Online Learning Capability of LLMs via Cross-Episode Meta-RL

Xiaofeng Lin, Sirou Zhu, Yilei Chen +6

Large language models (LLMs) achieve strong performance when all task-relevant information is available upfront, as in static prediction and instruction-following problems. However…

cs.CR2025

CCFC: Core & Core-Full-Core Dual-Track Defense for LLM Jailbreak Protection

Jiaming Hu, Haoyu Wang, Debarghya Mukherjee +1

Jailbreak attacks pose a serious challenge to the safe deployment of large language models (LLMs). We introduce CCFC (Core & Core-Full-Core), a dual-track, prompt-level defense fra…

stat.ML2025

Improving Mixup Calibration with Wasserstein Distributionally Robust Optimization

Jiaming Hu, Debarghya Mukherjee, Yeping Jin +1

In many real-world applications, ensuring the robustness and stability of deep neural networks (DNNs) is crucial, particularly for image classification tasks that encounter various…

cs.LG2025

Distributionally Robust Learning in Survival Analysis

Yeping Jin, Lauren Wise, Ioannis Ch. Paschalidis

We introduce an innovative approach that incorporates a Distributionally Robust Learning (DRL) approach into Cox regression to enhance the robustness and accuracy of survival predi…