Papers

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Google Scholar

Publications

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$^{*}$: corresponding author

• Stochastic subgradient methods with guaranteed global stability in nonsmooth nonconvex optimization
  N. Xiao, X. Hu*, K. C. Toh
  Mathematical Programming, accepted.
  
• Developing Lagrangian-based methods for nonsmooth nonconvex optimization
  N. Xiao, K. Ding*, X. Hu, K. C. Toh
  Mathematics of Operations Research, 2026.
  
• A minimization approach for minimax optimization with coupled constraints
  X. Hu, K. C. Toh, S. Wang, N. Xiao*
  SIAM Journal on Optimization, 2026, 36(2), 811-840.
  
• Learning-rate-free Momentum SGD with Reshuffling Converges in Nonsmooth Nonconvex Optimization
  X. Hu, N. Xiao*, X. Liu, K. C. Toh
  Journal of Scientific Computing 102, 85 (2025).
  
• CDOpt: a Python package for a class of Riemannian optimization
  N. Xiao, X. Hu*, X. Liu, K. C. Toh
  Mathematical Programming Computation, 2025.
  Software package: CDOpt.
  
• Adam-family Methods for Nonsmooth Optimization with Convergence Guarantees
  N. Xiao, X. Hu*, X. Liu, K. C. Toh
  Journal of Machine Learning Research, 25(48):1–53, 2024
  
• A constraint dissolving approach for nonsmooth optimization over the stiefel manifold
  X. Hu, N. Xiao*, X. Liu, K. C. Toh
  IMA Journal of Numerical Analysis, Volume 44, Issue 6, November 2024, Pages 3717–3748.
  
• Convergence properties of stochastic proximal subgradient method in solving a class of composite optimization problems with cardinality regularizer
  X. Hu, X. Liu, N. Xiao*
  Journal of Industrial and Management Optimization, 2024, 20(5): 1934-1950.
  
• An improved unconstrained approach for bilevel optimization
  X. Hu, N. Xiao*, X. Liu, K. C. Toh
  SIAM Journal on Optimization, 2023, 33(4): 2801-2829.
  
• Carbon Emissions Abatement(CEA) Allocation Based on Inverse Slack-Based Model(SBM)
  X. Hu, J. Li, X. Li, J.C. Cui*
  Journal of the Operation Research Society of China. 2021, 9: 475-498.
  
• A Fast Exact Algorithm for Airplane Refueling Problem
  J. Li*, X. Hu, J. Luo, J.C. Cui
  International Conference on Combinatorial Optimization and Applications. Cham: SpringerInternational Publishing, 2019.
  

Preprints

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• Partial Envelope for Optimization Problem with Nonconvex Constraints
  X. Hu, K. C. Toh, X. Liu,N. Xiao*.
  arXiv preprint arXiv:2510.22223.
  
• A hybrid subgradient method for nonsmooth nonconvex bilevel optimization
  N. Xiao, X. Hu*, X. Liu, K. C. Toh
  arXiv preprint arXiv:2505.22040.