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We consider a dictionary learning problem whose objective is to design a dictionary such that the signals admits a sparse or an approximate sparse representation over the learned dictionary. Such a problem finds a variety of applications…

Machine Learning · Computer Science 2015-03-10 Linxiao Yang , Jun Fang , Hong Cheng , Hongbin Li

We commonly refer to state-estimation theory in geosciences as data assimilation. This term encompasses the entire sequence of operations that, starting from the observations of a system, and from additional statistical and dynamical…

Atmospheric and Oceanic Physics · Physics 2018-06-11 Alberto Carrassi , Marc Bocquet , Laurent Bertino , Geir Evensen

We develop an algebraic framework for sequential data assimilation of partially observed dynamical systems. In this framework, Bayesian data assimilation is embedded in a non-abelian operator algebra, which provides a representation of…

Statistics Theory · Mathematics 2023-03-29 David Freeman , Dimitrios Giannakis , Brian Mintz , Abbas Ourmazd , Joanna Slawinska

State estimation for nonlinear state space models (SSMs) is a challenging task. Existing assimilation methodologies predominantly assume Gaussian posteriors on physical space, where true posteriors become inevitably non-Gaussian. We propose…

Machine Learning · Computer Science 2025-06-02 Yuta Tarumi , Keisuke Fukuda , Shin-ichi Maeda

In this paper, we introduce a new sparsity-promoting prior, namely, the "normal product" prior, and develop an efficient algorithm for sparse signal recovery under the Bayesian framework. The normal product distribution is the distribution…

Machine Learning · Statistics 2017-08-25 Zhou Zhou , Kaihui Liu , Jun Fang

In this paper we introduce and analyze an algorithm for continuous data assimilation for a three-dimensional Brinkman-Forchheimer-extended Darcy (3D BFeD) model of porous media. This model is believed to be accurate when the flow velocity…

Analysis of PDEs · Mathematics 2016-03-23 Peter A. Markowich , Edriss S. Titi , Saber Trabelsi

In this paper, we propose a Bayesian MAP estimator for solving the deconvolution problems when the observations are corrupted by Poisson noise. Towards this goal, a proper data fidelity term (log-likelihood) is introduced to reflect the…

Applications · Statistics 2011-03-14 François-Xavier Dupé , Jalal Fadili , Jean-Luc Starck

This paper addresses variational data assimilation from a learning point of view. Data assimilation aims to reconstruct the time evolution of some state given a series of observations, possibly noisy and irregularly-sampled. Using automatic…

Computational Physics · Physics 2021-11-10 Ronan Fablet , Bertrand Chapron , Lucas. Drumetz , Etienne Memin , Olivier Pannekoucke , Francois Rousseau

Data assimilation, in its most comprehensive form, addresses the Bayesian inverse problem of identifying plausible state trajectories that explain noisy or incomplete observations of stochastic dynamical systems. Various approaches have…

Machine Learning · Computer Science 2023-11-01 François Rozet , Gilles Louppe

Starting from limited measurements of a turbulent flow, data assimilation (DA) attempts to estimate all the spatio-temporal scales of motion. Success is dependent on whether the system is observable from the measurements, or how much of the…

Fluid Dynamics · Physics 2026-02-16 Andrew Cleary , Qi Wang , Tamer A. Zaki

Many applications in machine learning or signal processing involve nonsmooth optimization problems. This nonsmoothness brings a low-dimensional structure to the optimal solutions. In this paper, we propose a randomized proximal gradient…

Optimization and Control · Mathematics 2020-04-29 Dmitry Grishchenko , Franck Iutzeler , Jérôme Malick

Adaptive sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. A sequential adaptive sampling-and-refinement procedure called Distilled Sensing (DS) is proposed and analyzed. DS is a form of…

Statistics Theory · Mathematics 2010-05-31 Jarvis Haupt , Rui Castro , Robert Nowak

Data assimilation (DA) methods use priors arising from differential equations to robustly interpolate and extrapolate data. Popular techniques such as ensemble methods that handle high-dimensional, nonlinear PDE priors focus mostly on state…

Machine Learning · Statistics 2024-06-05 Rafael Anderka , Marc Peter Deisenroth , So Takao

This paper presents a novel centralized, variational data assimilation approach for calibrating transient dynamic models in electrical power systems, focusing on load model parameters. With the increasing importance of inverter-based…

Optimization and Control · Mathematics 2023-11-15 Ahmed Attia , D. Adrian Maldonado , Emil Constantinescu , Mihai Anitescu

We study predictive density estimation under Kullback-Leibler loss in $\ell_0$-sparse Gaussian sequence models. We propose proper Bayes predictive density estimates and establish asymptotic minimaxity in sparse models. A surprise is the…

Statistics Theory · Mathematics 2017-08-01 Gourab Mukherjee , Iain M. Johnstone

Sparse variational approximations allow for principled and scalable inference in Gaussian Process (GP) models. In settings where several GPs are part of the generative model, theses GPs are a posteriori coupled. For many applications such…

Machine Learning · Statistics 2017-11-30 Vincent Adam

Low-order thermoacoustic models are qualitatively correct, but they are typically quantitatively inaccurate. We propose a time-domain bias-aware method to make qualitatively low--order models quantitatively (more) accurate. First, we…

Fluid Dynamics · Physics 2022-11-10 Andrea Nóvoa , Luca Magri

Conjugate priors allow for fast inference in large dimensional vector autoregressive (VAR) models but, at the same time, introduce the restriction that each equation features the same set of explanatory variables. This paper proposes a…

Econometrics · Economics 2020-08-27 Niko Hauzenberger , Florian Huber , Luca Onorante

In this paper we adopt the familiar sparse, high-dimensional linear regression model and focus on the important but often overlooked task of prediction. In particular, we consider a new empirical Bayes framework that incorporates data in…

Statistics Theory · Mathematics 2020-07-28 Ryan Martin , Yiqi Tang

The article considers the problem of estimating a high-dimensional sparse parameter in the presence of side information that encodes the sparsity structure. We develop a general framework that involves first using an auxiliary sequence to…

Methodology · Statistics 2019-10-21 Trambak Banerjee , Gourab Mukherjee , Wenguang Sun