“…For example, for the forward problem, some of the popular choices of machine learning tools are Gaussian process [3,4,5,6,7] and deep neural networks (DNNs) [8,9,10,11,12]. For inverse problems, similar methods have been advanced, e.g., Bayesian estimation [13] and variational Bayes inference [14], and have been proposed for a wide variety of objectives, from parameter estimation [15] to discovering partial differential equations [16,17,18,19] to learning constitutive relationships [20].…”