Neural networks such as encoder-decoder architectures, UNet, and Transformers have achieved remarkable success in image processing and sequence modeling, yet a comprehensive mathematical understanding of their structure remains limited. In this talk, we present a unified, operator-theoretic framework that interprets these architectures through the lens of control theory, multigrid methods, and continuous modeling. We show that popular encoder-decoder networks—including UNet—can be derived as time-discretized solutions to control problems using operator-splitting and multigrid decomposition. Specifically, we introduce PottsMGNet, a network derived from the two-phase Potts model, and demonstrate how it generalizes many encoder-decoder designs. We further extend this perspective to Transformers, modeling self-attention as a non-local integral operator within a continuous integro-differential framework, and interpreting normalization as time-dependent constraints. These insights not only offer a rigorous theoretical foundation for key neural architectures but also open new paths for principled architecture design, robustness, and interpretability across tasks in vision and language.

台雪成,现任挪威研究中心首席科学家,曾担任Bergen大学教授,Oslo大学教授,新加坡南洋理工大学教授,香港浸会大学数学系讲座教授及系主任、香港脑血管健康工程中心(COCHE)首席研究员及执行项目总监。长期从事计算数学、图像计算及反问题、变分优化算法及应用等方面的研究。在SIAM Journal on Scientific Computing、SIAM Journal on Numerical Analysis、IJCV、IEEE TIP、CVPR、ECCV等国际顶级期刊及会议共发表学术论文260余篇,同时担任SIAM Journal on Numerical Analysis、SIAM Journal on Imaging Science、JMIV等多个国际知名期刊编委。曾于2009年获得第八届冯康科学计算奖,2011年获得新加坡南洋理工大学南洋突出研究贡献奖,并于2026年当选美国工业与应用数学学会(SIAM)会士(SIAM Fellow)。