collaborators

5 papers

cs.CL2026

Crayotter: Learning Long-Horizon Video Editing Agents via Group-Relative Preference Backpropagation

Lecheng Yan, Jianze Lin, Yichong Zhang +5

Long-horizon video editing agents receive final-product feedback only after many interdependent decisions. Yet editing quality is subjective, admits multiple valid solutions, and i…

cs.CV2026

Crayotter: Traceable Multi-Agent Workflows for Long-Form Video Editing

Lecheng Yan, Yichong Zhang, Xiantao Xu +12

Long-form video editing over heterogeneous footage requires agents to coordinate source selection, multimodal analysis, timeline construction, narration and subtitle alignment, ren…

cs.CR2026

Trust No Tool: Evaluating and Defending LLM Agents under Untrusted Tool Feedback

Lecheng Yan, Ruizhe Li, Xicheng Han +5

Tool-using LLM agents increasingly rely on external tools to make consequential decisions, yet most existing agent-security benchmarks and defenses implicitly assume that tool feed…

cs.LG2026

Spurious Rewards Paradox: Mechanistically Understanding How RLVR Activates Memorization Shortcuts in LLMs

Lecheng Yan, Ruizhe Li, Guanhua Chen +5

Reinforcement Learning with Verifiable Rewards (RLVR) is highly effective for enhancing LLM reasoning, yet recent evidence shows models like Qwen 2.5 achieve significant gains even…

cs.CL2024

Large Language Models as Code Executors: An Exploratory Study

Chenyang Lyu, Lecheng Yan, Rui Xing +4

The capabilities of Large Language Models (LLMs) have significantly evolved, extending from natural language processing to complex tasks like code understanding and generation. We…