1 code implementation • 31 Jan 2024 • Nicolas Boullé, Diana Halikias, Samuel E. Otto, Alex Townsend
There is a mystery at the heart of operator learning: how can one recover a non-self-adjoint operator from data without probing the adjoint?
no code implementations • 1 Nov 2023 • Samuel E. Otto, Nicholas Zolman, J. Nathan Kutz, Steven L. Brunton
In this paper, we provide a unifying theoretical and methodological framework for incorporating symmetry into machine learning models in three ways: 1. enforcing known symmetry when training a model; 2. discovering unknown symmetries of a given model or data set; and 3. promoting symmetry during training by learning a model that breaks symmetries within a user-specified group of candidates when there is sufficient evidence in the data.
1 code implementation • 28 Jul 2023 • Samuel E. Otto, Gregory R. Macchio, Clarence W. Rowley
To begin to address these issues, we introduce a parametric class of nonlinear projections described by constrained autoencoder neural networks in which both the manifold and the projection fibers are learned from data.
1 code implementation • 20 Sep 2022 • Samuel E. Otto, Sebastian Peitz, Clarence W. Rowley
Data-driven models for nonlinear dynamical systems based on approximating the underlying Koopman operator or generator have proven to be successful tools for forecasting, feature learning, state estimation, and control.
no code implementations • 28 Jul 2022 • Samuel E. Otto, Alberto Padovan, Clarence W. Rowley
We provide an efficient snapshot-based computational method analogous to balanced proper orthogonal decomposition.
no code implementations • 27 Jan 2021 • Samuel E. Otto, Clarence W. Rowley
In order to remedy these problems, we introduce a novel data-driven approach for sensor placement and feature selection for a general type of nonlinear inverse problem based on the information contained in secant vectors between data points.
no code implementations • 18 May 2019 • Samuel E. Otto, Clarence W. Rowley
Instead, we propose to identify a small collection of the original variables which are capable of uniquely determining all others either locally via immersion or globally via embedding of the underlying manifold.
no code implementations • 4 Dec 2017 • Samuel E. Otto, Clarence W. Rowley
This paper describes a method for learning low-dimensional approximations of nonlinear dynamical systems, based on neural-network approximations of the underlying Koopman operator.