activity
20242026
collaborators

10 papers

cs.LG2026

Understanding Reasoning from Pretraining to Post-Training

Jingyan Shen, Ang Li, Salman Rahman +4

Reinforcement learning (RL) has become central to improving large language models (LLMs) on complex reasoning tasks, yet RL post-training is largely studied in isolation from the p…

cs.CV2026

Towards Privacy-Preserving Federated Prompt Tuning under Data Heterogeneity: A Subspace-Decomposed Expert Approach

Yuhua Wang, Xiaodong Li, Yihao Guo +6

Federated prompt tuning (FPT) enables collaborative adaptation of vision--language models (VLMs) using lightweight prompts. Existing methods often address heterogeneity and privacy…

cs.CV2026

Taming Noise-Induced Prototype Degradation for Privacy-Preserving Personalized Federated Fine-Tuning

Yuhua Wang, Qinnan Zhang, Xiaodong Li +6

Prototype-based Personalized Federated Learning (ProtoPFL) enables efficient multi-domain adaptation by communicating compact class prototypes, but directly sharing them poses priv…

cs.CR2026

Mask-Free Privacy Extraction and Rewriting: A Domain-Aware Approach via Prototype Learning

Xiaodong Li, Yuhua Wang, Qingchen Yu +5

Client-side privacy rewriting is crucial for deploying LLMs in privacy-sensitive domains. However, existing approaches struggle to balance privacy and utility. Full-text methods of…

cs.AI2026

MonitorBench: A Comprehensive Benchmark for Chain-of-Thought Monitorability in Large Language Models

Han Wang, Yifan Sun, Brian Ko +8

Large language models (LLMs) can generate chains of thought (CoTs) that are not always causally responsible for their final outputs. When such a mismatch occurs, the CoT no longer…

cs.AI2025

When Reasoning Meets Its Laws

Junyu Zhang, Yifan Sun, Tianang Leng +4

Despite the superior performance of Large Reasoning Models (LRMs), their reasoning behaviors are often counterintuitive, leading to suboptimal reasoning capabilities. To theoretica…

cs.LG2025

Learning a Zeroth-Order Optimizer for Fine-Tuning LLMs

Kairun Zhang, Haoyu Li, Yanjun Zhao +2

Zeroth-order optimizers have recently emerged as an attractive approach for fine-tuning large language models (LLMs), as they avoid backpropagation and can substantially reduce mem…

cs.LG2025

Improving Data Efficiency for LLM Reinforcement Fine-tuning Through Difficulty-targeted Online Data Selection and Rollout Replay

Yifan Sun, Jingyan Shen, Yibin Wang +4

Reinforcement learning (RL) has become an effective approach for fine-tuning large language models (LLMs), particularly to enhance their reasoning capabilities. However, RL fine-tu…

cs.AI2025

The Emperor's New Clothes in Benchmarking? A Rigorous Examination of Mitigation Strategies for LLM Benchmark Data Contamination

Yifan Sun, Han Wang, Dongbai Li +2

Benchmark Data Contamination (BDC)-the inclusion of benchmark testing samples in the training set-has raised increasing concerns in Large Language Model (LLM) evaluation, leading t…

cs.LG2024

SVIP: Towards Verifiable Inference of Open-source Large Language Models

Yifan Sun, Yuhang Li, Yue Zhang +2

The ever-increasing size of open-source Large Language Models (LLMs) renders local deployment impractical for individual users. Decentralized computing has emerged as a cost-effect…