Research Excellence Shines in CCDS’s Outstanding PhD Thesis Award 2025

Two PhD graduates from CCDS have been named joint recipients of this year’s Outstanding PhD Thesis Award (OPTA) 2025, in recognition of their pioneering work that advances both the theoretical foundations of data search and the practical frontiers of visual content restoration. 

The OPTA is CCDS’s highest internal honour for PhD research, presented annually to graduates whose dissertations demonstrate originality, rigour, and far-reaching impact. For the 2025 cycle (1 April 2024 – 31 March 2025), the jury comprised Assoc Prof Chia Liang Tien (Chair), Assoc Prof Ke Yiping, and Assoc Prof Li Yi (SPMS). 

Dr Gao Jianyang was recognised for his thesis, Reliable, Efficient and Light Distance Computation on High-Dimensional Vectors. He made significant technical contributions to approximate nearest neighbour (ANN) search on high-dimensional vector data, a fundamental problem with applications in information retrieval, recommendations, and retrieval-based large language models. His work proposed an effective solution to the distance comparison bottleneck in existing ANN algorithms; designed the RaBitQ algorithm, which performs distance comparisons via bitwise operations to reduce computation time; and extended RaBitQ to further reduce storage costs. These contributions have been deployed in open-source libraries including Meta’s Faiss and Apache Lucene. 

Dr Zhou Shangchen received the award for his thesis, Exploring Priors for Visual Content Restoration and Enhancement. His research made contributions spanning algorithms, datasets, and applications. By exploring internal, degradation, and generative priors, he achieved superior and practical solutions for visual content restoration. His work introduced the restoration paradigm of code prediction; improved video propagation with a dual domain strategy; and defined the new task of joint deblurring and enhancement in the dark. His blind face restoration framework CodeFormer has become a widely used tool in AI arts, with over 50 million online accesses. His research has also been translated into commercial products and was recognised with an Honourable Mention in the WAIC Youth Outstanding Paper Award (2023). 

In addition to the joint winners, the jury awarded Honourable Mentions to Dr Jiang Yuming (Controllable Image and Video Synthesis) and Dr Ju Ce (Geometric Methods for Covariance-Based Neural Decoding). 

This year’s award showcases the range of research excellence among CCDS’s PhD graduates—from core algorithmic breakthroughs to advances in AI applications. It reflects CCDS’s mission to nurture research that advances knowledge while addressing challenges of broad societal and technological relevance.