Education 

• 2011-2015:  Ph.D. in Mathematical Sciences, Nanyang Technological University, Singapore

• 2003-2008: Specialist (equivalent to a master's degree) in Computational and Applied Mathematics, Lomonosov Moscow State University, Russia 

Working Experience 

• Jan 2023 - Dec 2023: Postdoctoral Researcher, University of Mons, Belgium

• Oct 2021 - Dec 2022: Applied Mathematics Research Scientist, Huawei Belgium Research Center, Leuven, Belgium

• Aug 2018 - Sep 2021: Postdoctoral Researcher, University of Mons,  Belgium

• Jul 2015 - Jul 2018: Research Fellow, National University of Singapore, Singapore

• Aug 2008 - Dec 2010: Lecturer, HCMC University of Education, Vietnam

Publications  (in chronological order of first appearance) 

2024

1. L. T. K. Hien, V. Leplat,  N Gillis, "Block Majorization Minimization with Extrapolation and Application to β-NMF",  accepted in SIAM J. on Mathematics of Data Science. [arXiv] [Matlab]

2023

2. V. Leplat, L. T. K. Hien,  A. Onwunta,  N Gillis, "Deep Nonnegative Matrix Factorization with Beta Divergences", accepted in Neural Computation. [arXiv] [Matlab]

3. L. T. K. Hien, S. Patra, S. Ben Taieb, "Anomaly detection with semi-supervised classification based on risk estimators",  Transactions on Machine Learning Research. [arXiv] [Python] [OpenReview]

2022

4. L. T. K. Hien, D. Papadimitriou, "An inertial ADMM for a class of nonconvex composite optimization with nonlinear coupling constraints",  Journal of Global Optimization, 89, pp. 927–948, 2024. [doi] [arXiv] [Matlab]

5. L. T. K. Hien, D. Papadimitriou, "Multiblock ADMM for nonsmooth nonconvex optimization with nonlinear coupling constraints", accepted in Optimization [doi] [arXiv] [Matlab]

2021

6. L. T. K. Hien*, D. N. Phan*, N. Gillis, M. Ahookhosh, P. Patrinos, "Block Alternating Bregman Majorization Minimization with Extrapolation", SIAM J. on Mathematics of Data Science, 4 (1), pp. 1-25, 2022. [doi] [pdf] [Matlab] (*: equal contribution)

7. L. T. K. Hien*, D. N. Phan*, N. Gillis, "Inertial Alternating Direction Method of Multipliers for Non-Convex Non-Smooth Optimization", Computational Optimization and Applications, 83, pp. 247–285, 2022. [doi] [arXiv] [Matlab] (*: equal contribution)

8. O. Vu Thanh, A.M.S. Ang, N. Gillis, L. T. K. Hien, "Inertial Majorization-Minimization Algorithm for Minimum-Volume NMF", EUSIPCO 2021, 23-27 August, Dublin. [pdf] [Matlab]

2020

9. L. T. K. Hien, D. N. Phan, N. Gillis, "An Inertial Block Majorization Minimization Framework for Nonsmooth Nonconvex Optimization", Journal of Machine Learning Research, 24 (18), pp. 1-41, 2023. [arXiv] [Matlab] [pdf]

10. L. T. K. Hien and N. Gillis, "Algorithms for Nonnegative Matrix Factorization with the Kullback-Leibler Divergence",  Journal of Scientific Computing 87, 93,  2021. [doi] [arXiv] [Matlab] 

11. M. Ahookhosh, L. T. K. Hien, N. Gillis, P. Patrinos,  "A block inertial Bregman proximal algorithm for nonsmooth nonconvex problems with application to symmetric nonnegative matrix tri-factorization",  Journal of Optimization Theory and Applications,  190, pp. 234–258, 2021. [doi] [arXiv]

12. A.M.S. Ang, J.E. Cohen, N. Gillis, L. T. K. Hien, "Accelerating Block Coordinate Descent for Nonnegative Tensor Factorization",   Numerical Linear Algebra with Applications, 2021. [doi] [arXiv] [Matlab] 

13. A. M .S. Ang, J. E. Cohen, L. T. K. Hien, N. Gillis,  "Extrapolated Alternating Algorithms for Approximate Canonical Polyadic Decomposition", ICASSP 2020, May 4-8, 2020, Barcelona. [doi] [pdf] [code]

2019

14. M. Ahookhosh, L. T. K. Hien, N. Gillis, P. Patrinos, "Multi-block Bregman proximal alternating linearized minimization and its application to orthogonal nonnegative matrix factorization", Computational Optimization and Applications, 79, pp. 681-715, 2021. [doi] [arXiv] [Matlab] 

15. N. Gillis, L. T. K. Hien, V. Leplat, V. Y. F. Tan, "Distributionally Robust and Multi-Objective Nonnegative Matrix Factorization", IEEE Trans. on Pattern Analysis and Machine Intelligence, 2021. [doi] [arXiv] [Matlab] 

16. L. T. K. Hien, N. Gillis, P. Patrinos, "Inertial Block Proximal Method for Non-Convex Non-Smooth Optimization", The 37th International Conference on Machine Learning ICML 2020. [doi] [pdf] [Matlab] [poster]

2018

17. L. T. K. Hien, C. B. Chua,  "A global linear and local superlinear/quadratic inexact non-interior continuation method for variational inequalities", Set-Valued and Variational Analysis, 29, pp. 109–144, 2021. [doi] [arXiv]

18. L. T. K. Hien, M. Sim, H. Xu,  "Mitigating Interdiction Risk with Fortification", Operations Research, 68 (2), pp. 348-362, 2020. [doi] [pdf] 

2017

19. L. T. K. Hien*, R. Zhao*, W. B. Haskell,  "An inexact primal-dual smoothing framework for large-scale non-bilinear saddle point problems",  Journal of Optimization Theory and Applications, 200, pp. 34–67, 2024. [doi] [arXiv] (*: equal contribution)

2016

20. L. T. K. Hien, C. V. Nguyen, H. Xu, C. Lu, J. Feng, "Accelerated Randomized Mirror Descent Algorithms For Composite Non-strongly Convex Optimization", Journal of Optimization Theory and Applications, 181, pp. 541–566, 2019. [doi] [arXiv] 

2015

21. C. B. Chua, L. T. K. Hien,  "A Superlinearly convergent smoothing Newton continuation algorithm for variational inequalities over definable sets", SIAM Journal on Optimization, 25, pp. 1034–1063, 2015. [doi]

22. L. T. K. Hien,  "Differential properties of Euclidean projection onto power cone", Mathematical Methods of Operations Research, 82, pp. 265–284, 2015. [doi]