Welcome to My Website


My name is Sijia Cai and I received my B.Sc and M.Sc degrees (supervisor: Ping Wang) at Tianjin University, all majoring in mathematics. Now I'm a PhD candidate (supervisor: Lei Zhang) in the Department of Computing at Hong Kong Polytechnic University, My research focuses on modeling, algorithm design and mathematical analysis for computer vision and machine learning problems. I am particularly interested in such topics as deep learning and weakly-supervised learning.


  • 11/2014 ~ now                         PhD Candidate, Department of Computing, The Hong Kong Polytechnic University, Hong Kong, China.
  • 09/2011 ~ 07/2014                   M.Sc.,  Department of MathematicsTianjin UniversityTianjin, China.
  • 09/2007~ 07/2011                    B.Sc.,   Department of Mathematics, Tianjin University, Tianjin, China.


  • S. Cai,  W. Zuo, L. Zhang, "Higher-order Integration of Hierarchical Convolutional Activations for Fine-grained Visual Categorization", in ICCV 2017. (paper) (code)
  • S. Cai, L. Zhang, W. Zuo, X. Feng, "A Probabilistic Collaborative Representation based Approach for Pattern Classification", in CVPR 2016. (paper) (code)
  • L. Li, P. Wang, Q. Hu, S. Cai, "Efficient Background Modeling Based on Sparse Representation and Outlier Iterative Removal," In  IEEE Transactions on Circuits and Systems for Video Technology 26.2 (2016): 278-289.
  • S. Cai, W. Zuo, L. Zhang, X. Feng, and P. Wang, "Support Vector Guided Dictionary Learning," in ECCV 2014. (paper, sup) (code)
  • S. Cai, P. Wang, L. Li, C. Zhang, "Higher-Order Principal Component Pursuit via Tensor Approximation and Convex Optimization," in Journal of Systems Engineering and Electronicsvol. 25, issue 3, pp. 523-530, 2014.
  • P. Wang, C. Zhang, S. Cai, L. Li, "Accelerated Matrix Recovery via Random Projection Based on Inexact Augmented Lagrange Multiplier Method," in Transactions of Tianjin Universityvol. 19, issue 4, pp. 293-299, 2013.


  • Address: Room PQ724C, Mong Man Wai Building, The Hong Kong Polytechnic University, Hong Kong
  • Telephone: +00852 6996 9024
  • E-mail: cssjcai@gmail.com