I am a Postdoctoral Fellow at the CityU–Oxford Joint Centre for Intelligent Multidimensional Data Analysis (CIMDA), Hong Kong, funded by Research Talent Hub for Innovation and Technology Fund (ITF) and advised by Prof. Hong Yan. I received my B.S. degrees in Information and Computational Mathematics from the School of Mathematical Sciences, Fudan University, and in Data Science from the School of Data Science, Fudan University. I also obtained my Ph.D. in Computational Mathematics from the School of Mathematical Sciences, Fudan University, advised by Prof. Yimin Wei.

My research interests include numerical methods for tensor and matrix learning, interpretable representation, and acceleration of large model inference. You can find my publications on Google Scholar

🔥 News

📝 Publications

• AML Numerical radius approach to asymptotic stability of quaternion-tensor delay systems, Renjie Xu, Wanli Ma, Maolin Che

NeuIPS 2025

DuSA: Fast and Accurate Dual-Stage Sparse Attention Mechanism Accelerating Both Training and Inference

Chong Wu, Jiawang Cao, Renjie Xu, Zhuoheng Ran, Maolin Che, Wenbo Zhu, Hong Yan

• A novel and effective dual-stage sparse attention (DuSA) mechanism
• A mathematical relationship between DuSA and VSA is given
• DuSA can approximate VSA with a low error
• DuSA surpasses state-of-the-art (SOTA) methods in different tasks

• LMA LU decomposition and generalized Autoone-Takagi decomposition of dual matrices and their applications, Renjie Xu, Yimin Wei, Hong Yan  · 
• IJPAM A Linearized Alternating Direction Method of Multipliers for Solving Complex Semi-Symmetric Tensor Equations and its Applications, Shenghao Feng, Yimin Wei, Renjie Xu, Eric King-wah Chu
• arXiv An Interpretable Two-Stage Feature Decomposition Method for Deep Learning-based SAR ATR, Chenwei Wang, Renjie Xu, Congwen Wu, Cunyi Yin, Ziyun Liao, Deqing Mao, Sitong Zhang, Hong Yan
• arXiv sparseGeoHOPCA: A Geometric Solution to Sparse Higher-Order PCA Without Covariance Estimation, Renjie Xu, Chong Wu, Maolin Che, Zhuoheng Ran, Yimin Wei, Hong Yan
• JCAM An ADMM-based interior point method for solving nonnegative tensor least squares problems and its applications, Shenghao Feng, Yimin Wei, Renjie Xu
• IEEE TGRS Limited-data SAR ATR causal method via dual-invariance intervention, Chenwei Wang, Renjie Xu, Yulin Huang, Jifang Pei, Chuan Huang, Wenqi Zhu, Jianyu Yang
• ACM-MM 2025 ELFATT: Efficient linear fast attention for vision transformers, Chong Wu, Maolin Che, Renjie Xu, Zhuoheng Ran, Hong Yan
• AML QR decomposition of dual matrices and its application, Renjie Xu, Tong Wei, Yimin Wei, Pengpeng Xie  · 
• arXiv QR Decomposition of Dual Matrices and its Application to Traveling Wave Identification in the Brain, Renjie Xu, Tong Wei, Yimin Wei, Pengpeng Xie  · 
• NFAO CUR and generalized CUR decompositions of quaternion matrices and their applications, Renjie Xu, Shenghao Feng, Yimin Wei, Hong Yan  · 
• CAM UTV decomposition of dual matrices and its applications, Renjie Xu, Tong Wei, Yimin Wei, Hong Yan
• PJO Randomized quaternion matrix UTV decomposition and its applications in quaternion matrix optimization, Renjie Xu, Yimin Wei
• JCAM Low-rank traffic matrix completion with marginal information, Zikai Xiong, Yimin Wei, Renjie Xu, Yanwei Xu

🎖 Honors and Awards

• 2024.02-now Research Talent Hub for Innovation and Technology Fund (ITF)
• 2024.01 Shanghai Outstanding Gradute Student
• 2023 Scholarship for Outstanding Students in Fudan University
• 2022 Scholarship for Outstanding Students in Fudan University
• 2021 Scholarship for Outstanding Students in Fudan University
• 2020 Scholarship for Outstanding Students in Fudan University
• 2019.10 Excellent Doctoral Research Promotion Program
• 2019 Scholarship for Outstanding Students in Fudan University
• 2018 Scholarship for Outstanding Students in Fudan University
• 2016 Scholarship for Outstanding Students in Fudan University
• 2015.10 Second Prize, “Shenzhen Cup” Mathematical Modeling Competition
• 2015 Scholarship for Outstanding Students in Fudan University
• 2014 Scholarship for Outstanding Students in Fudan University

📖 Educations

• 2017.09 - 2024.01, Doctor of Philosophy, School of Mathematical Sciences, Fudan University, Shanghai
• 2014.09 - 2017.06, Bachelor of Science, School of Data Sciences, Fudan University, Shanghai
• 2013.09 - 2017.06, Bachelor of Science, School of Mathematical Sciences, Fudan University, Shanghai

💬 Invited Talks

• 2025.06, CIMDA/Oxford Seminars, CIMDA
• 2022.09, Applied Math PhD Seminar, Fudan University

💻 Internships

• 2020.07 - 2021.01, Huawei, Shanghai.

🏞️ Hobbies

• Hiking — Certified Outdoor Mountaineering Instructor by the China Mountaineering Association
• Football — Level 3 Referee certified by the Chinese Football Association
• Rowing — Star 3 Qualification by the China Rowing Association