activity
20242026
collaborators

25 papers

cs.LG2026

Beyond Distribution Matching: Selective Margin Preservation for Supervised Fine-Tuning

Yuxuan Wang, Guangxiang Zhao, Xinyu Tan +6

Supervised fine-tuning (SFT) changes logit margins among non-target tokens at teacher-forced prefixes. Matching a local reference distribution keeps those probabilities and also pe…

cs.AI2026

ScienceArena: Benchmarking LLMs on Latest Scientific Olympiad Competitions

Guangxiang Zhao, Qilong Shi, Xusen Xiao +13

Benchmark saturation and data contamination increasingly obscure genuine scientific reasoning in frontier LLMs. We introduce \textsc{ScienceArena}, an olympiad-style benchmark from…

cs.CL2026

ArborMem: Navigating Interaction States with Memory Forests

Zongwei Lv, Yuemeng Xu, Yilun Yao +8

Large language models increasingly serve as persistent conversational assistants, requiring memory that preserves relevant experience and maintains continuity across interactions.…

cs.AI2026

When Do Prompt-Side Agent Playbooks Transfer? Accuracy, Cost, and Runtime Shift in Agent Deployment

Weihong Lin, Lin Sun, Xiangzheng Zhang

Prompt-side playbooks can improve tool-using language agents without retraining, but their portability beyond the source setting is unclear. We study frozen playbook transfer under…

cs.CL2026

External Experience Serving in Production LLM Systems: A Deployment-Oriented Study of Quality-Cost Trade-offs

Lin Sun, Heming Zhang, Xiangzheng Zhang

Production LLM systems accumulate reusable operational experience, but the practical deployment issue is not merely whether such experience can help. It is how different serving st…

cs.CL2026

RealClawBench: Live OpenClaw Benchmarks from Real Developer-Agent Sessions

Zongwei Lv, Yaoming Li, Zhewen Tan +7

Agent benchmarks should reflect what users actually ask deployed agents to do, yet existing benchmarks often miss key realism properties of real developer-agent sessions. We introd…

cs.CL2026

A Primer in Post-Training Reasoning Data: What We Know About How It Works

Yaoming Li, Guangxiang Zhao, Qilong Shi +3

Post-training has become a primary driver of recent progress in large reasoning models, and reasoning data are often the key variable determining whether this stage succeeds. Work…

cs.AI2026

Harness-Bench: Evaluating Agent Harnesses across Models and Realistic Workflows

Yilun Yao, Xinyu Tan, Chao-Hsuan Liu +10

LLM agents are increasingly deployed as executable systems that use tools, modify workspaces, and produce concrete artifacts. In such workflows, performance depends not only on the…

cs.AI2026

MemAudit: Post-hoc Auditing of Poisoned Agent Memory via Causal Attribution and Structural Anomaly Detection

Zhewen Tan, Yilun Yao, Huiyan Jin +9

Large language model agents increasingly rely on persistent memory to store past interactions, retrieve relevant demonstrations, and improve long-horizon task execution. However, t…

cs.CV2026

When Good OCR Is Not Enough: Benchmarking OCR Robustness for Retrieval-Augmented Generation

Lin Sun, Wang Dexian, Jingang Huang +4

Industrial Retrieval-Augmented Generation (RAG) systems depend on optical character recognition (OCR) to transform visual documents into text. Existing OCR benchmarks rely on chara…

cs.AI2026

Thinking with Reasoning Skills: Fewer Tokens, More Accuracy

Guangxiang Zhao, Qilong Shi, Xusen Xiao +3

Reasoning LLMs often spend substantial tokens on long intermediate reasoning traces (e.g., chain-of-thought) when solving new problems. We propose to summarize and store reusable r…

cs.AI2026

Beyond Parameter Arithmetic: Sparse Complementary Fusion for Distribution-Aware Model Merging

Weihong Lin, Lin Sun, Qilong Shi +6

Model merging has emerged as a promising paradigm for composing the capabilities of large language models by directly operating in weight space, enabling the integration of special…

cs.CL2026

Beyond Static Alignment: Hierarchical Policy Control for LLM Safety via Risk-Aware Chain-of-Thought

Jianfeng Si, Lin Sun, Weihong Lin +1

Large Language Models (LLMs) face a fundamental safety-helpfulness trade-off due to static, one-size-fits-all safety policies that lack runtime controllabilityxf, making it difficu…

cs.LG2026

TriPlay-RL: Tri-Role Self-Play Reinforcement Learning for LLM Safety Alignment

Zhewen Tan, Wenhan Yu, Jianfeng Si +9

In recent years, safety risks associated with large language models have become increasingly prominent, highlighting the urgent need to mitigate the generation of toxic and harmful…

cs.CL2026

BEAR: Budgeted Evidence Allocation for Multi-Document Reasoning

Lin Sun, Linglin Zhang, Jingang Huang +3

We argue that multi-document reasoning is constrained not only by how much text a model can read, but also by how limited query-time evidence budget is allocated across documents a…

cs.CV2025

TextlessRAG: End-to-End Visual Document RAG by Speech Without Text

Peijin Xie, Shun Qian, Bingquan Liu +3

Document images encapsulate a wealth of knowledge, while the portability of spoken queries enables broader and flexible application scenarios. Yet, no prior work has explored knowl…

cs.CL2025

Router Upcycling: Leveraging Mixture-of-Routers in Mixture-of-Experts Upcycling

Junfeng Ran, Guangxiang Zhao, Yuhan Wu +7

The Mixture-of-Experts (MoE) models have gained significant attention in deep learning due to their dynamic resource allocation and superior performance across diverse tasks. Howev…

cs.AI2025

Uncertainty Under the Curve: A Sequence-Level Entropy Area Metric for Reasoning LLM

Yongfu Zhu, Lin Sun, Guangxiang Zhao +2

In this work, we introduce Entropy Area Score (EAS), a simple yet effective metric to quantify uncertainty in the answer generation process of reasoning large language models (LLMs…

cs.CL2025

Efficient Switchable Safety Control in LLMs via Magic-Token-Guided Co-Training

Jianfeng Si, Lin Sun, Zhewen Tan +1

Current methods for content safety in Large Language Models (LLMs), such as Supervised Fine-Tuning (SFT) and Reinforcement Learning from Human Feedback (RLHF), often rely on multi-…

cs.AI2025

Evaluation is All You Need: Strategic Overclaiming of LLM Reasoning Capabilities Through Evaluation Design

Lin Sun, Weihong Lin, Jinzhu Wu +8

Reasoning models represented by the Deepseek-R1-Distill series have been widely adopted by the open-source community due to their strong performance in mathematics, science, progra…

cs.CL2025

TinyR1-32B-Preview: Boosting Accuracy with Branch-Merge Distillation

Lin Sun, Guangxiang Zhao, Xiaoqi Jian +18

The challenge of reducing the size of Large Language Models (LLMs) while maintaining their performance has gained significant attention. However, existing methods, such as model di…

cs.CL2025

Chain-of-Thought Matters: Improving Long-Context Language Models with Reasoning Path Supervision

Dawei Zhu, Xiyu Wei, Guangxiang Zhao +7

Recent advances in Large Language Models (LLMs) have highlighted the challenge of handling long-context tasks, where models need to reason over extensive input contexts to aggregat…

cs.CL2025

LongAttn: Selecting Long-context Training Data via Token-level Attention

Longyun Wu, Dawei Zhu, Guangxiang Zhao +5

With the development of large language models (LLMs), there has been an increasing need for significant advancements in handling long contexts. To enhance long-context capabilities…

cs.CL2025

Large Language Models Badly Generalize across Option Length, Problem Types, and Irrelevant Noun Replacements

Guangxiang Zhao, Saier Hu, Xiaoqi Jian +5

In this paper, we propose a ``Generalization Stress Test" to assess Large Language Models' (LLMs) generalization ability under slight and controlled perturbations, including option…