I am a final year Ph.D. student in Information and Telecommunication Engineering at
Xidian University, advised by
Prof. Bo Chen. I received my bachelor's degree in
Electronic Engineering from Xidian University in 2022.
My research focuses on finding and leveraging sparse, dynamic, yet highly informative learning signals in
foundation models—from efficient attention and multimodal concept learning to reward signals and credit assignment
in post-training. I am currently interested in agentic post-training and
Recursive Self-Improvement (RSI).
I also worked as an LLM Research Intern at BandAI, ByteDance, and as a Project Up Intern at the Yuanbao
AI-Infra team, Tencent.
Yan Xie, Sijie Zhu, Tiansheng Wen, Bo Chen, Yifei Wang
Reveals that later rollout tokens provide lower-quality teacher supervision, then derives importance weighting
that emphasizes earlier, more reliable tokens for faster and stronger on-policy distillation.
Yan Xie†, Tiansheng Wen†, Tangda Huang, Bo Chen, Chenyu You, Stefanie Jegelka, Yifei Wang
Introduces Sparse Feature Attention and an IO-aware FlashSFA kernel, using sparse query/key features to cut
attention cost while preserving dense-model quality on long-context tasks.
Yan Xie, Zequn Zeng, Hao Zhang, Yucheng Ding, Yi Wang, Zhengjue Wang, Bo Chen, Hongwei Liu
Models local image patches and concepts as an optimal-transport problem, producing explicit fine-grained
alignments and more reliable concept predictions.
Zequn Zeng†, Yan Xie†, Hao Zhang, Chiyu Chen, Bo Chen, Zhengjue Wang
Uses textual memory and retrieve-then-filter concept selection to generate grounded zero-shot captions with
fewer hallucinations and stronger generalization.
Built evaluation and data-synthesis pipelines for e-commerce agents, deployed Agentic OPD for post-training,
and studied stale-sample mitigation in fully asynchronous agentic reinforcement learning.
2026
Yuanbao AI-Infra, Tencent
Project Up Intern
Developed model-sparsification methods for inference efficiency and deployed Sparse Feature Attention in
production workflows.