activity
20242026
collaborators

9 papers

cs.LG2026

What Does Multi-Turn Reinforcement Learning Really Improve in LLM Agents?

Kejian Zhu, Zhuoran Jin, Shangqing Tu +5

While multi-turn agentic reinforcement learning (RL) excels on long-horizon tasks, its performance gains remain highly sensitive to interaction constraints. Evaluating across sampl…

cs.CL2026

SFT Conflicts, RL Coexists: A Theoretical and Empirical Analysis of Multi-Task Learning for LLMs

Kejian Zhu, Zhuoran Jin, Shangqing Tu +5

Supervised Fine-Tuning (SFT) and Reinforcement Learning (RL) exhibit fundamentally different behaviors in enhancing multi-task reasoning for large language models (LLMs). Our preli…

cs.CV2026

Beyond Simply Environment Scaling: Designing Effective Environment Distributions for Multimodal Agent Learning

Kejian Zhu, Zhuoran Jin, Dongqi Huang +4

Recent works train agents by constructing large-scale multimodal environment pools. However, we find that simply increasing the number of multimodal environments does not always be…

cs.CL2026

Look Light, Think Heavy: What Multimodal Chain-of-Thought Reasoning Can and Cannot Do

Zhuoran Jin, Kejian Zhu, Hongbang Yuan +5

Chain-of-Thought (CoT) has become a standard method for improving reasoning capabilities in large language models (LLMs) by eliciting step-by-step thinking, but its effectiveness i…

cs.CL2026

Agentic Environment Engineering for Large Language Models: A Survey of Environment Modeling, Synthesis, Evaluation, and Application

Jiachun Li, Zhuoran Jin, Tianyi Men +12

Environments serve as interactive systems for large language model (LLM) based agents across diverse scenarios and play a crucial role in driving the continual evolution of model c…

cs.CL2025

Omni-Reward: Towards Generalist Omni-Modal Reward Modeling with Free-Form Preferences

Zhuoran Jin, Hongbang Yuan, Kejian Zhu +5

Reward models (RMs) play a critical role in aligning AI behaviors with human preferences, yet they face two fundamental challenges: (1) Modality Imbalance, where most RMs are mainl…

cs.CL2025

Establishing Trustworthy LLM Evaluation via Shortcut Neuron Analysis

Kejian Zhu, Shangqing Tu, Zhuoran Jin +3

The development of large language models (LLMs) depends on trustworthy evaluation. However, most current evaluations rely on public benchmarks, which are prone to data contaminatio…

cs.CV2025

MMR-V: What's Left Unsaid? A Benchmark for Multimodal Deep Reasoning in Videos

Kejian Zhu, Zhuoran Jin, Hongbang Yuan +6

The sequential structure of videos poses a challenge to the ability of multimodal large language models (MLLMs) to locate multi-frame evidence and conduct multimodal reasoning. How…

cs.CL2024

DICE: Detecting In-distribution Contamination in LLM's Fine-tuning Phase for Math Reasoning

Shangqing Tu, Kejian Zhu, Yushi Bai +3

The advancement of large language models (LLMs) relies on evaluation using public benchmarks, but data contamination can lead to overestimated performance. Previous researches focu…