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The generation of initial conditions via accurate data assimilation is crucial for weather forecasting and climate modeling. We propose DiffDA as a denoising diffusion model capable of assimilating atmospheric variables using predicted…

Computational Engineering, Finance, and Science · Computer Science 2024-06-11 Langwen Huang , Lukas Gianinazzi , Yuejiang Yu , Peter D. Dueben , Torsten Hoefler

We present the new method DALI (Derivative Approximation for LIkelihoods) for reconstructing and forecasting posteriors. DALI extends the Fisher Matrix formalism but allows for a much wider range of posterior shapes. While the Fisher Matrix…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-10 Elena Sellentin , Miguel Quartin , Luca Amendola

A framework for data assimilation combining aspects of operator-theoretic ergodic theory and quantum mechanics is developed. This framework adapts the Dirac--von Neumann formalism of quantum dynamics and measurement to perform sequential…

Mathematical Physics · Physics 2019-09-18 Dimitrios Giannakis

Pedestrian attribute recognition is an important multi-label classification problem. Although the convolutional neural networks are prominent in learning discriminative features from images, the data imbalance in multi-label setting for…

Computer Vision and Pattern Recognition · Computer Science 2020-05-22 Yang Hu , Xiaying Bai , Pan Zhou , Fanhua Shang , Shengmei Shen

In this study, we explore data assimilation for the Stochastic Camassa-Holm equation through the application of the particle filtering framework. Specifically, our approach integrates adaptive tempering, jittering, and nudging techniques to…

Numerical Analysis · Mathematics 2024-02-13 Colin John Cotter , Dan Crisan , Maneesh Kumar Singh

Dimensional analysis (DA) pays attention to fundamental physical dimensions such as length and mass when modelling scientific and engineering systems. It goes back at least a century to Buckingham's Pi theorem, which characterizes a…

Machine Learning · Computer Science 2023-12-19 G. Alexi Rodriguez-Arelis , William J. Welch

We propose closed-form conditional diffusion models for data assimilation. Diffusion models use data to learn the score function (defined as the gradient of the log-probability density of a data distribution), allowing them to generate new…

Machine Learning · Statistics 2026-04-02 Brianna Binder , Agnimitra Dasgupta , Assad Oberai

Data assimilation (DA) is crucial for enhancing solutions to partial differential equations (PDEs), such as those in numerical weather prediction, by optimizing initial conditions using observational data. Variational DA methods are widely…

Machine Learning · Computer Science 2025-09-30 Hamidreza Moazzami , Asma Jamali , Nicholas Kevlahan , Rodrigo A. Vargas-Hernández

Multivariate Gaussian processes (GPs) offer a powerful probabilistic framework to represent complex interdependent phenomena. They pose, however, significant computational challenges in high-dimensional settings, which frequently arise in…

Variational Data Assimilation (DA) has enabled huge improvements in the skill of operational weather forecasting. In this study, we use a simple solar-wind propagation model to develop the first solar-wind variational DA scheme. This scheme…

Space Physics · Physics 2018-10-19 Matthew Lang , Mathew Owens

Data interpolation is a fundamental step in any seismic processing workflow. Among machine learning techniques recently proposed to solve data interpolation as an inverse problem, Deep Prior paradigm aims at employing a convolutional neural…

Signal Processing · Electrical Eng. & Systems 2021-01-28 Francesco Picetti , Vincenzo Lipari , Paolo Bestagini , Stefano Tubaro

Data assimilation is the task to combine evolution models and observational data in order to produce reliable predictions. In this paper, we focus on ensemble-based recursive data assimilation problems. Our main contribution is a hybrid…

Numerical Analysis · Mathematics 2016-02-26 Nawinda Chustagulprom , Sebastian Reich , Maria Reinhardt

The weather and climate domains are undergoing a significant transformation thanks to advances in AI-based foundation models such as FourCastNet, GraphCast, ClimaX and Pangu-Weather. While these models show considerable potential, they are…

Machine Learning · Computer Science 2024-07-18 Junqi Yin , Siming Liang , Siyan Liu , Feng Bao , Hristo G. Chipilski , Dan Lu , Guannan Zhang

In inverse problems, the goal is to estimate unknown model parameters from noisy observational data. Traditionally, inverse problems are solved under the assumption of a fixed forward operator describing the observation model. In this…

Numerical Analysis · Mathematics 2024-09-26 Simon Weissmann , Neil K. Chada , Xin T. Tong

Recent advances in Image Restoration (IR) have been largely driven by generative methods such as Diffusion Models and Flow Matching, which excel in synthesizing realistic textures while suffering from slow multi-step inference and…

Computer Vision and Pattern Recognition · Computer Science 2026-05-21 Yi Liu , Jia Ma , Wengen Li , Jihong Guan , Shuigeng Zhou , Yichao Zhang

There is an urgent need to build models to tackle Indoor Air Quality issue. Since the model should be accurate and fast, Reduced Order Modelling technique is used to reduce the dimensionality of the problem. The accuracy of the model, that…

Accurate estimation of error covariances (both background and observation) is crucial for efficient observation compression approaches in data assimilation of large-scale dynamical problems. We propose a new combination of a covariance…

Numerical Analysis · Mathematics 2021-06-11 Sibo Cheng , Didier Lucor , Jean-Philippe Argaud

Data assimilation algorithms integrate prior information from numerical model simulations with observed data. Ensemble-based filters, regarded as state-of-the-art, are widely employed for large-scale estimation tasks in disciplines such as…

Numerical Analysis · Mathematics 2024-05-24 Iris Rammelmüller , Gottfried Hastermann , Jana de Wiljes

This work is about a slow-fast data assimilation system under non-Gaussian noisy fluctuations. Firstly, we show the existence of a random invariant manifold for a stochastic dynamical system with non-Gaussian noise and two-time scales.…

Probability · Mathematics 2018-11-12 Yanjie Zhang , Huijie Qiao , Jinqiao Duan

A non-intrusive data assimilation methodology is developed to improve the statistical predictions of large-eddy simulations (LES). The ensemble-variational (EnVar) approach aims to minimize a cost function that is defined as the discrepancy…

Fluid Dynamics · Physics 2021-09-28 Vincent Mons , Yifan Du , Tamer A. Zaki
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