collaborators

7 papers

cs.CL2025

RePO: Replay-Enhanced Policy Optimization

Siheng Li, Zhanhui Zhou, Wai Lam +2

Reinforcement learning (RL) is vital for optimizing large language models (LLMs). Recent Group Relative Policy Optimization (GRPO) estimates advantages using multiple on-policy out…

cs.AI2025

SafeCoT: Improving VLM Safety with Minimal Reasoning

Jiachen Ma, Zhanhui Zhou, Chao Yang +1

Ensuring safe and appropriate responses from vision-language models (VLMs) remains a critical challenge, particularly in high-risk or ambiguous scenarios. We introduce SafeCoT, a l…

cs.CV2025

Mitigating Object Hallucination via Robust Local Perception Search

Zixian Gao, Chao Yang, Zhanhui Zhou +2

Recent advancements in Multimodal Large Language Models (MLLMs) have enabled them to effectively integrate vision and language, addressing a variety of downstream tasks. However, d…

cs.CV2025

VLMs Can Aggregate Scattered Training Patches

Zhanhui Zhou, Lingjie Chen, Chao Yang +1

One way to mitigate risks in vision-language models (VLMs) is to remove dangerous samples in their training data. However, such data moderation can be easily bypassed when harmful…

cs.LG2025

Adversarial Preference Learning for Robust LLM Alignment

Yuanfu Wang, Pengyu Wang, Chenyang Xi +13

Modern language models often rely on Reinforcement Learning from Human Feedback (RLHF) to encourage safe behaviors. However, they remain vulnerable to adversarial attacks due to th…

cs.CL2025

Emergent Response Planning in LLMs

Zhichen Dong, Zhanhui Zhou, Zhixuan Liu +2

In this work, we argue that large language models (LLMs), though trained to predict only the next token, exhibit emergent planning behaviors: $\textbf{their hidden representations…