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The dynamic mode decomposition (DMD) is a broadly applicable dimensionality reduction algorithm that approximates a matrix containing time-series data by the outer product of a matrix of exponentials, representing Fourier-like time…

Optimization and Control · Mathematics 2017-12-07 Travis Askham , Peng Zheng , Aleksandr Aravkin , J. Nathan Kutz

The Dynamic Mode Decomposition (DMD)---a popular method for performing data-driven Koopman spectral analysis---has gained increased adoption as a technique for extracting dynamically meaningful spatio-temporal descriptions of fluid flows…

Fluid Dynamics · Physics 2017-07-13 Maziar S. Hemati , Clarence W. Rowley , Eric A. Deem , Louis N. Cattafesta

The time-dependent fields obtained by solving partial differential equations in two and more dimensions quickly overwhelm the analytical capabilities of the human brain. A meaningful insight into the temporal behaviour can be obtained by…

Numerical Analysis · Mathematics 2024-04-04 Miha Rot , Martin Horvat , Gregor Kosec

The current work is concerned with studying processes for constructing reduced-order models capable of performing transonic aeroelastic stability analyses in the frequency domain based on computational fluid dynamics (CFD) techniques. The…

Fluid Dynamics · Physics 2023-07-21 Ana Cristina Neves Carloni , João Luiz F. Azevedo

Feedback control synthesis for nonlinear, parameter-dependent fluid flow control problems is considered. The optimal feedback law requires the solution of the Hamilton-Jacobi-Bellman (HJB) PDE suffering the curse of dimensionality. This is…

Optimization and Control · Mathematics 2023-11-29 Sergey Dolgov , Dante Kalise , Luca Saluzzi

The present study investigates unsteady wake dynamics in flow past oscillating cylinder. Two-dimensional computational study is carried out for flow past sinusoidally oscillating cylinder. Operating parameters like Reynolds number, forcing…

Fluid Dynamics · Physics 2022-01-25 Anubhav Sinha , Parasuram IVLN

In this paper we study the influence of including snapshots that approach the velocity time derivative in the numerical approximation of the incompressible Navier-Stokes equations by means of proper orthogonal decomposition (POD) methods.…

Numerical Analysis · Mathematics 2022-11-01 Bosco García-Archilla , Volker John , Julia Novo

Direct numerical simulations, performed with a high-order spectral-element method, are used to study coherent structures in turbulent pipe flow at friction Reynolds numbers $Re_{\tau} = 180$ and $550$. The database was analysed using…

Fluid Dynamics · Physics 2023-07-19 Leandra Abreu , André Cavalieri , Philipp Schlatter , Ricardo Vinuesa , Dan Henningson

In this paper, we propose an augmented subspace based adaptive proper orthogonal decomposition (POD) method for solving the time dependent partial differential equations. By augmenting the POD subspace with some auxiliary modes, we obtain…

Numerical Analysis · Mathematics 2023-04-19 Xiaoying Dai , Miao Hu , Jack Xin , Aihui Zhou

Dynamic mode decomposition (DMD) has emerged as a popular data-driven modeling approach to identifying spatio-temporal coherent structures in dynamical systems, owing to its strong relation with the Koopman operator. For dynamical systems…

Signal Processing · Electrical Eng. & Systems 2021-10-26 Manu Krishnan , Serkan Gugercin , Pablo A. Tarazaga

Dynamic Mode Decomposition (DMD) is a powerful data-driven method used to extract spatio-temporal coherent structures that dictate a given dynamical system. The method consists of stacking collected temporal snapshots into a matrix and…

Machine Learning · Computer Science 2021-05-11 Gabriel F. Barros , Malú Grave , Alex Viguerie , Alessandro Reali , Alvaro L. G. A. Coutinho

We introduce a new adaptive decomposition tool, which we refer to as Nonlinear Mode Decomposition (NMD). It decomposes a given signal into a set of physically meaningful oscillations for any waveform, simultaneously removing the noise. NMD…

Numerical Analysis · Mathematics 2015-10-07 Dmytro Iatsenko , Peter V. E. McClintock , Aneta Stefanovska

Mode-based model-reduction is used to reduce the degrees of freedom of high dimensional systems, often by describing the system state by a linear combination of spatial modes. Transport dominated phenomena, ubiquitous in technical and…

Numerical Analysis · Mathematics 2020-02-28 Julius Reiss

This study presents an artificial neural network and proper orthogonal decomposition (POD)-based reduced-order model (ROM) of turbulent flow around a finite wall-mounted square cylinder. The proposed model is suitable for turbulent wake…

Fluid Dynamics · Physics 2021-09-21 Mustafa Z. Yousif , Hee Chang Lim

Dynamic Mode Decomposition (DMD) is an equation-free method that aims at reconstructing the best linear fit from temporal datasets. In this paper, we show that DMD does not provide accurate approximation for datasets describing oscillatory…

Numerical Analysis · Mathematics 2023-03-14 Alessandro Alla , Angela Monti , Ivonne Sgura

A proper orthogonal decomposition-based B-splines B\'ezier elements method (POD-BSBEM) is proposed as a non-intrusive reduced-order model for uncertainty propagation analysis for stochastic time-dependent problems. The method uses a…

Numerical Analysis · Mathematics 2021-05-20 Azzedine Abdedou , Azzeddine Soulaïmani

Dynamic mode decomposition (DMD) has proven to be a valuable tool for the analysis of complex flow-fields but the application of this technique to flows with moving boundaries is not straightforward. This is due to the difficulty in…

Fluid Dynamics · Physics 2020-07-28 Karthik Menon , Rajat Mittal

Koopman decomposition is a non-linear generalization of eigen-decomposition, and is being increasingly utilized in the analysis of spatio-temporal dynamics. Well-known techniques such as the dynamic mode decomposition (DMD) and its linear…

Dynamical Systems · Mathematics 2021-05-12 Shaowu Pan , Nicholas Arnold-Medabalimi , Karthik Duraisamy

There is a broad need in the neuroscience community to understand and visualize large-scale recordings of neural activity, big data acquired by tens or hundreds of electrodes simultaneously recording dynamic brain activity over minutes to…

Neurons and Cognition · Quantitative Biology 2015-11-24 Bingni W. Brunton , Lise A. Johnson , Jeffrey G. Ojemann , J. Nathan Kutz

In part I of the article, we demonstrated that a variant of the Dynamic Mode Decomposition (DMD) algorithm based on variable projection optimization, called Optimized DMD (OPT-DMD), enables a robust identification of the dominant…

Plasma Physics · Physics 2023-08-29 Farbod Faraji , Maryam Reza , Aaron Knoll , J. Nathan Kutz