Draft:Defeng Sun

Defeng Sun (Chinese name: 孙德锋) is a Chinese applied mathematician and operations researcher. He holds the position of Chair Professor of Applied Optimization and Operations Research, and has been serving as the Head of Department of Applied Mathematics since 2019. Additional, he is the Director of the Research Centre for Intelligent Operations Research (2024 - present) at The Hong Kong Polytechnic University (PolyU), a role he has held since 2024. Beyond his duties at PolyU, Sun had been the President of The Hong Kong Mathematical Society in 2020-2024.

Education
Sun received his Ph.D. degree in 1995 from Chinese Academy of Sciences in Beijing under the supervision of Professor Jiye Han (Chinese name: 韩继业), after obtaining his bachelor’s and Master’s degree from Nanjing University in 1989 and 1992, respectively.

Research
Sun’s research interests lie in the broad areas of non-convex continuous optimization and machine learning including mathematical theory, algorithmic developments and real-world applications.

On the theoretical part, Sun is best known for his 2006 work of solving a decades-long open problem in variational analysis characterizing the strong regularity of nonlinear semidefinite programming. Focusing on the development of efficient optimization algorithms for solving large scale complex optimization problems, including SDPNAL/SDPNAL+ for general purpose large scale semidefinite programming, codes for correlations matrix calibrations and LassoNAL for statistical regression models, Sun devised a world-recognized second-order sparsity solution that renders data with more precision and depth than traditional methods, efficiently separating useful data from useless data and uncovering minute information on a large scale. This solution is the first of its kind revolutionizing the way of leveraging data and making prediction.

Academic Career
Prior to his appointment as Chair Professor at PolyU in 2017, Sun served as Professor at Department of Mathematics, National University of Singapore (Year 2000 – 2017) and Deputy Director (Research) at the NUS Risk Management Institute.

Professional Activities
Sun is a member of various professional societies including The Institute for Operations Research and the Management Science (INFORMS), Society for Industrial and Applied Mathematics (SIAM), Mathematical Optimization Society (MOS), American Mathematical Society (AMS), China Society for Industrial and Applied Mathematics (CSIAM) and The Hong Kong Mathematical Society (HKMS) etc.

He actively involves in editorial activities for various leading scientific journals:
 * Associate Editor, Mathematical Programming (Series A, August 2007 -- present); Series B, January 2014--December 2017).
 * Associate Editor, SIAM Journal on Optimization (January 2012-- present).
 * Associate Editor, Journal of the Operations Research Society of China (2012--present).
 * Associate Editor, Journal of Computational Mathematics (2017--present).
 * Associate Editor, Science China Mathematics (January 2018 -- present).
 * Associate Editor, Journal of Optimization Theory and Applications (2021 – present).
 * Advisory Committee Member, Asia-Pacific Journal of Operational Research (January 2014-- present); editor-in-chief (October 2010 –December 2013).

He also served as the co-chair of the organizing committee and local organizing committee for the SIAM Conference on Optimization (OP21), program committee member for The Sixth International Conference on Continuous Optimization (ICCOPT 2019) in Berlin and The Fifth International Conference on Continuous Optimization (ICCOPT 2016) in Tokyo.

Awards and recognitions
Sun was ranked among the world’s top 2% most-cited scientists by Stanford University in 2021-2023, and awarded Research Grant Council (RGC) Senior Research Fellowship in 2022/23.

He was invited as a plenary speaker at The Seventh International Conference on Continuous Optimization (ICCOPT 2022) in 2022, SIAM Conference on Computational Science and Engineering (CSE21) in 2021 and SIAM Conference on Optimization (OP11) in 2011.

In 2020, he was elected as one of the eight Inaugural Fellows of CSIAM, and SIAM in recognition of his contributions to algorithms and software for conic optimization, particularly matrix optimization.

Together with Kim-Chuan Toh and Liuqin Yang, Sun was awarded the triennial Beale--Orchard-Hays Prize for Excellence in Computational Mathematical Programming 2018 by the Mathematical Optimization Society.