Dr. ZHANG Guojun's Story

Dr. ZHANG Guojun
PhD Graduate
Department of Applied Mathematics

My dream is to develop impactful algorithms that create real computational value for both research and society. I am driven by the belief that rigorous mathematical theory—when transformed into efficient and scalable algorithms—can improve decision-making, optimize large-scale systems, and enhance the computational tools that support people’s daily lives.

In 2020, amid the pandemic, travel and visa restrictions disrupted my original plan to pursue doctoral study in the United States. PolyU and Prof. Defeng Sun provided me with flexible and timely support to continue my PhD journey. I will always be grateful for this opportunity and the support I received at such a critical moment.

At PolyU, my research focused on fast and robust optimization algorithms, which lie at the core of many modern computational systems. I especially enjoyed turning theoretical ideas into practical, efficient tools for large-scale problems. One of the most meaningful moments was seeing how a small theoretical insight, paired with careful implementation, could deliver clear performance gains on real-world tasks. Building on this foundation, we developed several efficient HPR solvers for large-scale optimization problems, leveraging modern GPUs to achieve substantial acceleration.

I am truly thankful for the guidance and trust from my supervisor and peers. Prof. Sun’s dedication and patience meant a great deal to me. He encouraged my independence while offering thoughtful advice, shaping me into a more reflective and resilient researcher.

My training at PolyU has equipped me to tackle challenging problems, communicate research effectively, and deliver work that balances mathematical rigour with real-world impact. Through seminars, workshops, and academic exchanges, I have broadened my perspective and built lasting connections within the optimization community.

Advice to prospective students: follow what you truly love, build strong foundations, and iterate bravely—prove, implement, test, and refine. Stay curious, engage with the academic community, and never be afraid to ask for help and feedback. PolyU offers strong support and opportunities for those who are committed to research.