Partial differential equations are often used in the spatial-temporal modeling of complex dynamical systems in many engineering applications. In this work, we build on the recent progress of operator learning and present a data-driven modeling framework that is continuous in both space and time. A key feature of the proposed model is the resolution-invariance with respect to both spatial and temporal discretizations. To improve the long-term performance of the calibrated model, we further propose a hybrid optimization scheme that leverages both gradient-based and derivative-free optimization methods and efficiently trains on both short-term time series and long-term statistics. We investigate the performance of the spatial-temporal continuous learning framework with three numerical examples, including the viscous Burgers' equation, the Navier-Stokes equations, and the Kuramoto-Sivashinsky equation. The results confirm the resolution-invariance of the proposed modeling framework and also demonstrate stable long-term simulations with only short-term time series data. In addition, we show that the proposed model can better predict long-term statistics via the hybrid optimization scheme with a combined use of short-term and long-term data.

基于运算器学习的最近进展，本文提出了一种连续时空数据驱动建模框架，并通过三个数值实例研究了该框架的性能，结果证实了该建模框架的分辨率不变性，并展示了仅使用短期时间序列数据进行稳定长期模拟的能力，此外，也表明了通过混合优化方案，结合短期和长期数据，提出的模型能更好地预测长期统计数据。

连续时空模型的操作员学习及混合优化方案