Project Status: Active
We propose to develop a scalable black-box training framework for scientific machine learning (SciML) models that are non-trainable with existing automatic differentiation-based algorithms.
Our particular interest to this effort is to study how to train data-driven SciML models to learn missing physics of a complex system for advancing forward simulations. Specifically, this effort aims at achieving the following objectives: (1) develop a novel non-local gradient with structured sampling to enable non-local exploration for escaping from local minima and to achieve sufficient accuracy in gradient estimation; (2) advance theoretical analyses for a class of non-convex training problems to help domain scientists tune the hyper-parameters of the proposed training framework; and (3) exploit high-performance computing to accelerate the time to solution for black-box training problems for which loss functions involve computationally expensive black-box simulators. The proposed framework will be demonstrated on two distinct applications. The first is to train machine learning-based constitutive models to predict mercury dynamics in the Spallation Neutron Source mercury target, and the second is to train heat-source models to predict time-dependent laser scan paths that yield desirable micro-structures in three-dimensional printed metal components. This effort will advance the state of the art of several machine learning areas such as reinforcement learning and variational inference.
Last Updated: September 1, 2020 - 9:09 pm