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Related papers: A critical note on back-and-forth Data Assimilatio…

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Adjoint-based data assimilation for turbulent Navier-Stokes flows is fundamentally limited by the behavior of the adjoint dynamics: in backward time, adjoint fields exhibit exponential growth and become increasingly dominated by small-scale…

Fluid Dynamics · Physics 2026-02-17 Hongyi Ke , Zejian You , Qi Wang

We study a discrete-in-time data-assimilation algorithm based on nudging through a time-delayed feedback control in which the observational measurements have been contaminated by a Gaussian noise process. In the context of the…

Analysis of PDEs · Mathematics 2023-09-08 Emine Celik , Eric Olson

This paper proposes two proximal Newton-CG methods for convex nonsmooth optimization problems in composite form. The algorithms are based on a a reformulation of the original nonsmooth problem as the unconstrained minimization of a…

Optimization and Control · Mathematics 2014-03-03 Panagiotis Patrinos , Lorenzo Stella , Alberto Bemporad

This paper provides a detailed theoretical analysis of methods to approximate the solutions of high-dimensional (>10^6) linear Bayesian problems. An optimal low-rank projection that maximizes the information content of the Bayesian…

Data Analysis, Statistics and Probability · Physics 2019-10-28 Nicolas Bousserez , Daven K. Henze

This paper introduces a Bi-fidelity Asymptotic-Preserving Neural Network (BI-APNNs) framework, designed to efficiently solve forward and inverse problems for the semiconductor Boltzmann equation. Our approach builds upon the…

Numerical Analysis · Mathematics 2025-11-18 Liu Liu , Xueyu Zhu , Zhenyi Zhu

This article presents and assesses a framework for estimating temperature fields in real time for food-freezing applications, significantly reducing computational load while ensuring accurate temperature monitoring, which represents a…

Numerical Analysis · Mathematics 2025-06-03 Felipe Galarce , Diego Rivera , Douglas Pacheco , Alfonso Caiazzo , Ernesto Castillo

Data assimilation refers to the process of obtaining an estimate of a system's state using a model for the system's time evolution and a time series of measurements that are possibly noisy and incomplete. However, for practical reasons, the…

Chaotic Dynamics · Physics 2007-05-23 Matthew Cornick , Brian Hunt , Edward Ott , Michael F. Schatz

Many applications in computational and experimental fluid mechanics require effective methods for reconstructing the flow fields from limited sensor data. However, this task remains a significant challenge because the measurement operator,…

Fluid Dynamics · Physics 2024-11-22 Phong C. H. Nguyen , Joseph B. Choi , Quang-Trung Luu

Data assimilation algorithms are used to estimate the states of a dynamical system using partial and noisy observations. The ensemble Kalman filter has become a popular data assimilation scheme due to its simplicity and robustness for a…

Numerical Analysis · Mathematics 2021-06-23 Gottfried Hastermann , Maria Reinhardt , Rupert Klein , Sebastian Reich

Fractional-order dynamical networks are increasingly being used to model and describe processes demonstrating long-term memory or complex interlaced dependencies amongst the spatial and temporal components of a wide variety of dynamical…

Optimization and Control · Mathematics 2021-08-04 Sarthak Chatterjee , Andrea Alessandretti , A. Pedro Aguiar , Sérgio Pequito

We consider a recently introduced continuous data assimilation (CDA) approach for downscaling a coarse resolution configuration of the 2D Benard convection equations into a finer grid. In this CDA, a nudging term, estimated as the misfit…

Optimization and Control · Mathematics 2015-12-22 M. U. Altaf , E. S. Titi , O. M. Knio , L. Zhao , M. F. McCabe , I. Hoteit

Data assimilation method consists in combining all available pieces of information about a system to obtain optimal estimates of initial states. The different sources of information are weighted according to their accuracy by the means of…

Data Analysis, Statistics and Probability · Physics 2014-04-30 Angélique Ponçot , Jean-Philippe Argaud , Bertrand Bouriquet , Patrick Erhard , Serge Gratton , Olivier Thual

Analog-to-Digital Converters (ADCs) are essential components in modern data acquisition systems. A key design challenge is accommodating high dynamic range (DR) input signals without clipping. Existing solutions, such as oversampling,…

Signal Processing · Electrical Eng. & Systems 2024-12-18 Shaik Basheeruddin Shah , Satish Mulleti , Yonina C. Eldar

In recent years, the prosperity of deep learning has revolutionized the Artificial Neural Networks. However, the dependence of gradients and the offline training mechanism in the learning algorithms prevents the ANN for further improvement.…

Machine Learning · Computer Science 2020-10-07 Chong Chen , Qinghui Xing , Xin Ding , Yaru Xue , Tianfu Zhong

Dynamical networks are versatile models that can describe a variety of behaviours such as synchronisation and feedback. However, applying these models in real world contexts is difficult as prior information pertaining to the connectivity…

Dynamical Systems · Mathematics 2025-08-29 Eugene Tan , Débora Corrêa , Thomas Stemler , Michael Small

AI and data-driven models have large potential for data assimilation applications by creating fast and accurate forecasts. Their tendency to produce spurious inaccurate, nonphysical results -- hallucination -- however, raises a serious…

Computational Engineering, Finance, and Science · Computer Science 2026-04-28 Andrey A. Popov

We introduce a localized version of the nudging data assimilation algorithm for the periodic 2D Navier-Stokes equations in which observations are confined (i.e., localized) to a window that moves across the entire domain along a…

Analysis of PDEs · Mathematics 2023-01-05 Animikh Biswas , Zachary Bradshaw , Michael Jolly

In this report, a new fuzzy 2bit-AND parallel-to-OR, or simply, a fuzzy binary AND/OR (FBAR) text data compression model as an algorithm is suggested for bettering spatial locality limits on nodes during database transactions. The current…

Information Theory · Computer Science 2015-03-13 Philip B. Alipour

This paper considers continuous data assimilation (CDA) in partial differential equation (PDE) discretizations where nudging parameters can be taken arbitrarily large. We prove that long-time optimally accurate solutions are obtained for…

Numerical Analysis · Mathematics 2024-08-02 Amanda Diegel , Xuejian Li , Leo G. Rebholz

Methods based on Deep Learning have recently been applied on astrophysical parameter recovery thanks to their ability to capture information from complex data. One of these methods is the approximate Bayesian Neural Networks (BNNs) which…

Instrumentation and Methods for Astrophysics · Physics 2023-06-21 Héctor J. Hortúa , Luz Ángela García , Leonardo Castañeda C