(ZHANG Zaikun)

Current Position

• Apr. 2016–present, Assistant Professor (Research Assistant Professor up until Jan. 2018), Department of Applied Mathematics, Hong Kong Polytechnic University, Hong Kong, China

Research interests

• Mathematical optimization and its applications, especially

  • randomized methods

  • methods for large-scale problems

  • methods for noisy problems

  • derivative-free methods

Research papers

• S. Gratton, C. W. Royer, L. N. Vicente, Z. Zhang, Direct search based on probabilistic feasible descent for bound and linearly constrained problems, Comput. Optim. Appl., 72: 525–559, 2019 [pdf] [SpringerLink]

• X. Chen, C. T. Kelley, F. Xu, Z. Zhang, A smoothing direct search method for Monte Carlo-based bound constrained composite nonsmooth optimization, SIAM J. Sci. Comput., 40(4): A2174–A2199, 2018 [pdf] [SIAM epubs]

• S. Gratton, C. W. Royer, L. N. Vicente, Z. Zhang, Complexity and global rates of trust-region methods based on probabilistic models, IMA J. Numer. Anal., 38(3): 1579–1597, 2018 [pdf] [link]

• M. Dodangeh, L. N. Vicente, Z. Zhang, On the optimal order of worst case complexity of direct search, Optim. Lett., 10(4): 699–708, 2016 [pdf] [SpringerLink]

• S. Gratton, C. W. Royer, L. N. Vicente, Z. Zhang, Direct search based on probabilistic descent, SIAM J. Optim., 25(3): 1515–1541, 2015 [pdf] [SIAM epubs]

• Z. Zhang, Sobolev seminorm of quadratic functions with applications to derivative-free optimization, Math. Program., 146(1–2): 77–96, 2014 (based on sections 4.3–4.5 of my thesis) [pdf] [SpringerLink]

External grants

• Oct. 2020–Sept. 2023, “Derivative-free Optimization with Space Decomposition, Coarse Space Correction, and Randomization”, PI, awarded by the Research Grants Council (RGC) of Hong Kong under the General Research Fund (GRF)

• Jan. 2018–Dec. 2020, “Nonlinear Optimization Based on Inaccurate Information”, PI, awarded by the Research Grants Council (RGC) of Hong Kong under the Early Career Scheme (ECS)

• Jan. 2017–Dec. 2018, “Space Decomposition Methods for Constrained Optimization with Engineering Applications”, Hong Kong PI (French PI: S. Gratton; French Co-I: A. Gazaix), jointly awarded by the Research Grants Council (RGC) of Hong Kong and le Consulat Général de France à Hong Kong & Macao under the PROCORE - France/Hong Kong Joint Research Scheme

Education

• Sept. 2007–July 2012, Ph.D., Institute of Computational Mathematics and Scientific/Engineering Computing (ICMSEC), Chinese Academy of Sciences (CAS), supervised by Professor Ya-xiang Yuan, thesis: On derivative-free optimization methods (in Chinese, but with an English abstract)

• May 2010–Aug. 2010, visiting student, Institute for Computer Science, University of Bayreuth, Germany, visiting Professor Klaus Schittkowski, funded by Alexander von Humboldt Foundation

• Sept. 2003–July 2007, B.Sc., Department of Mathematics, Jilin University, China

Contact

• Address: TU824, Yip Kit Chuen Bldg., Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

• Email: zaikun.zhang [&] polyu.edu.hk, zaikunzhang [&] gmail.com

• Tel: +852-27664592

• Fax: +852-23629045