English
Related papers

Related papers: Total-Variation -- Fast Gradient Flow and Relation…

200 papers

A novel dynamic mode decomposition (DMD) method based on a Kalman filter is proposed. This paper explains the fast algorithm of the proposed Kalman filter DMD (KFDMD) in combination with truncated proper orthogonal decomposition for…

Fluid Dynamics · Physics 2018-11-09 Taku Nonomura , Hisaichi Shibata , Ryoji Takaki

Koopman operator theory shows how nonlinear dynamical systems can be represented as an infinite-dimensional, linear operator acting on a Hilbert space of observables of the system. However, determining the relevant modes and eigenvalues of…

Machine Learning · Computer Science 2022-04-06 Daniel J. Alford-Lago , Christopher W. Curtis , Alexander T. Ihler , Opal Issan

Dynamic Mode Decomposition (DMD) describes complex dynamic processes through a hierarchy of simpler coherent features. DMD is regularly used to understand the fundamental characteristics of turbulence and is closely related to Koopman…

Fluid Dynamics · Physics 2023-02-01 Matthew J. Colbrook , Lorna J. Ayton , Máté Szőke

The Dynamic-Mode Decomposition (DMD) is a well established data-driven method of finding temporally evolving linear-mode decompositions of nonlinear time series. Traditionally, this method presumes that all relevant dimensions are sampled…

Dynamical Systems · Mathematics 2021-01-13 Christopher W. Curtis , Daniel Jay Alford-Lago

Any deterministic autonomous dynamical system may be globally linearized by its' Koopman operator. This object is typically infinite-dimensional and can be approximated by the so-called Dynamic Mode Decomposition (DMD). In DMD, the central…

Dynamical Systems · Mathematics 2023-12-14 Gowtham S Seenivasaharagavan , Milan Korda , Hassan Arbabi , Igor Mezić

Data-driven dimensionality reduction methods such as proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) have proven to be useful for exploring complex phenomena within fluid dynamics and beyond. A well-known…

Fluid Dynamics · Physics 2022-12-27 Elena Marensi , Gökhan Yalnız , Björn Hof , Nazmi Burak Budanur

The dynamic mode decomposition (DMD) has become a leading tool for data-driven modeling of dynamical systems, providing a regression framework for fitting linear dynamical models to time-series measurement data. We present a simple…

Numerical Analysis · Mathematics 2017-04-11 Travis Askham , J. Nathan Kutz

Dynamic mode decomposition (DMD) is a popular technique for modal decomposition, flow analysis, and reduced-order modeling. In situations where a system is time varying, one would like to update the system's description online as time…

Optimization and Control · Mathematics 2017-07-11 Hao Zhang , Clarence W. Rowley , Eric A. Deem , Louis N. Cattafesta

Dynamic mode decomposition (DMD) is a data-driven technique used for capturing the dynamics of complex systems. DMD has been connected to spectral analysis of the Koopman operator, and essentially extracts spatial-temporal modes of the…

Optimization and Control · Mathematics 2017-09-12 Byron Heersink , Michael A. Warren , Heiko Hoffmann

A novel data-driven method of modal analysis for complex flow dynamics, termed as reduced-order variational mode decomposition (RVMD), has been proposed, combining the idea of the separation of variables and a state-of-the-art nonstationary…

Fluid Dynamics · Physics 2022-09-27 Zi-Mo Liao , Zhiye Zhao , Liang-Bing Chen , Zhen-Hua Wan , Nan-Sheng Liu , Xi-Yun Lu

We apply dynamic mode decomposition (DMD) and proper orthogonal decomposition (POD) methods to flows in highly-heterogeneous porous media to extract the dominant coherent structures and derive reduced-order models via Galerkin projection.…

Computational Physics · Physics 2015-06-12 Mehdi Ghommem , Victor M. Calo , Yalchin Efendiev

Dynamic Mode Decomposition (DMD) is a numerical method that seeks to fit timeseries data to a linear dynamical system. In doing so, DMD decomposes dynamic data into spatially coherent modes that evolve in time according to exponential…

Computer Vision and Pattern Recognition · Computer Science 2026-02-26 Marco Mignacca , Simone Brugiapaglia , Jason J. Bramburger

We develop a new generalization of Koopman operator theory that incorporates the effects of inputs and control. Koopman spectral analysis is a theoretical tool for the analysis of nonlinear dynamical systems. Moreover, Koopman is intimately…

Optimization and Control · Mathematics 2016-02-25 Joshua L. Proctor , Steven L. Brunton , J. Nathan Kutz

In this paper, we combine concepts of the generalized multiscale finite element method and mode decomposition methods to construct a robust local-global approach for model reduction of flows in high-contrast porous media. This is achieved…

Computational Physics · Physics 2013-01-25 Mehdi Ghommem , Michael Presho , Victor M. Calo , Yalchin Efendiev

The emergence of Dynamic Mode Decomposition (DMD) as a practical way to attempt a Koopman mode decomposition of a nonlinear PDE presents exciting prospects for identifying invariant sets and slowly decaying transient structures buried in…

Fluid Dynamics · Physics 2018-08-01 Jacob Page , Rich R. Kerswell

Total variation regularization and total variation flows (TVF) have been widely applied for image enhancement and denoising. To include a generic preservation of crossing curvilinear structures in TVF we lift images to the homogeneous space…

Analysis of PDEs · Mathematics 2019-07-02 Remco Duits , Etienne St-Onge , Jim Portegies , Bart Smets

We introduce the Rigged Dynamic Mode Decomposition (Rigged DMD) algorithm, which computes generalized eigenfunction decompositions of Koopman operators. By considering the evolution of observables, Koopman operators transform complex…

Dynamical Systems · Mathematics 2024-12-04 Matthew J. Colbrook , Catherine Drysdale , Andrew Horning

A data-driven analysis method known as dynamic mode decomposition (DMD) approximates the linear Koopman operator on projected space. In the spirit of Johnson-Lindenstrauss Lemma, we will use random projection to estimate the DMD modes in…

Machine Learning · Computer Science 2021-11-09 Sudam Surasinghe , Erik M. Bollt

A Koopman decomposition of a complex system leads to a representation in which nonlinear dynamics appear to be linear. The existence of a linear framework with which to analyse nonlinear dynamical systems brings new strategies for…

Fluid Dynamics · Physics 2019-03-12 Jeremy Parker , Jacob Page

This work continues the parametric investigation on the sampling nuances of the Dynamic Mode Decomposition (DMD) under the Koopman analysis. Through turbulent wakes, the investigation corroborated the generality of the universal convergence…