Events Calendar

Computational Science Distinguished Seminar

Speaker: George Haller, ETH Zürich

Talk Title: Nonlinear Spectral Model Reduction from Data

Abstract: Machine learning has been a major development in applied science and engineering, with impressive success stories in static learning environments like image, pattern, and speech recognition. Yet the modeling of dynamical phenomena—such as nonlinear vibrations of solids and transitions in fluids—remains a challenge for classic machine learning. Indeed, neural net models for nonlinear dynamics tend to be complex, uninterpretable and unreliable outside their training range.
 
In this talk, I discuss a dynamical systems alternative to neural networks in the data-driven reduced-order modeling of nonlinear phenomena. Specifically, I show that the recent concept of spectral submanifolds (SSMs) provides very low-dimensional attractors in a large family of mechanics problems ranging from wing oscillations to transitions in shear flows. A data-driven identification of the reduced dynamics on these SSMs gives a mathematically justified  way to construct accurate and predictive reduced-order models for solids, fluids and controls without the use of governing equations. I illustrate this on physical problems including the accelerated finite-element simulations of large structures, prediction of transitions to turbulence, reduced-order modeling of fluid-structure interactions, extraction of reduced equations of motion from videos, and model-predictive control of soft robots.

Biography: George Haller is a professor of Mechanical Engineering at ETH Zürich, where he holds the Chair in Nonlinear Dynamics and heads the Institute for Mechanical Systems. His prior appointments include tenured faculty positions at Brown, McGill and MIT. He also served as the inaugural director of Morgan Stanley’s fixed income modeling center. Professor Haller is a recipient of a Sloan Fellowship in mathematics, an ASME Thomas Hughes Young Investigator Award, a School of Engineering Distinguished Professorhip (McGill), and the Stanley Corrsin Award of the APS. He is an external member of the Hungarian Academy of Science and an elected fellow of SIAM, APS and ASME. He currently serves as feature editor at Nonlinear Dynamics and senior editor at the Journal of Nonlinear Science. His research focuses on nonlinear dynamical systems with applications to mechanical vibrations, coherent structures in turbulence, and data- and equation-driven model reduction for physical systems. He has authored three monographs in these areas.

Host: School of Advanced Computing

More Info: https://sac.usc.edu/events/

Location: Ronald Tutor Hall of Engineering (RTH) - 526

Audiences: Everyone Is Invited

Contact: Tessa Yao

Event Link: https://sac.usc.edu/events/