Search Results for author: Andrey A. Popov

Found 8 papers, 1 papers with code

Improving the Adaptive Moment Estimation (ADAM) stochastic optimizer through an Implicit-Explicit (IMEX) time-stepping approach

no code implementations20 Mar 2024 Abhinab Bhattacharjee, Andrey A. Popov, Arash Sarshar, Adrian Sandu

The Adam optimizer, often used in Machine Learning for neural network training, corresponds to an underlying ordinary differential equation (ODE) in the limit of very small learning rates.

Precision Mars Entry Navigation with Atmospheric Density Adaptation via Neural Networks

no code implementations17 Jan 2024 Felipe Giraldo-Grueso, Andrey A. Popov, Renato Zanetti

Discrepancies between the true Martian atmospheric density and the onboard density model can significantly impair the performance of spacecraft entry navigation filters.

Small-data Reduced Order Modeling of Chaotic Dynamics through SyCo-AE: Synthetically Constrained Autoencoders

no code implementations14 May 2023 Andrey A. Popov, Renato Zanetti

Data-driven reduced order modeling of chaotic dynamics can result in systems that either dissipate or diverge catastrophically.

Dimensionality Reduction

A Meta-learning Formulation of the Autoencoder Problem for Non-linear Dimensionality Reduction

no code implementations14 Jul 2022 Andrey A. Popov, Arash Sarshar, Austin Chennault, Adrian Sandu

A rapidly growing area of research is the use of machine learning approaches such as autoencoders for dimensionality reduction of data and models in scientific applications.

Dimensionality Reduction Meta-Learning

Physics-informed neural networks for PDE-constrained optimization and control

2 code implementations6 May 2022 Jostein Barry-Straume, Arash Sarshar, Andrey A. Popov, Adrian Sandu

A fundamental problem in science and engineering is designing optimal control policies that steer a given system towards a desired outcome.

Adjoint-Matching Neural Network Surrogates for Fast 4D-Var Data Assimilation

no code implementations16 Nov 2021 Austin Chennault, Andrey A. Popov, Amit N. Subrahmanya, Rachel Cooper, Ali Haisam Muhammad Rafid, Anuj Karpatne, Adrian Sandu

Surrogates constructed using adjoint information demonstrate superior performance on the 4D-Var data assimilation problem compared to a standard neural network surrogate that uses only forward dynamics information.

Weather Forecasting

Investigation of Nonlinear Model Order Reduction of the Quasigeostrophic Equations through a Physics-Informed Convolutional Autoencoder

no code implementations27 Aug 2021 Rachel Cooper, Andrey A. Popov, Adrian Sandu

Reduced order modeling (ROM) is a field of techniques that approximates complex physics-based models of real-world processes by inexpensive surrogates that capture important dynamical characteristics with a smaller number of degrees of freedom.

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