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Geosteering of wells requires fast interpretation of geophysical logs, which is a non-unique inverse problem. Current work presents a proof-of-concept approach to multi-modal probabilistic inversion of logs using a single evaluation of an…

Geophysics · Physics 2022-11-10 Sergey Alyaev , Ahmed H. Elsheikh

Zeeman-Doppler Imaging (ZDI) is a powerful inversion method to reconstruct stellar magnetic surface fields. The reconstruction process is usually solved by translating the inverse problem into a regularized least-square or optimization…

Solar and Stellar Astrophysics · Physics 2009-11-13 T. A. Carroll , M. Kopf , K. G. Strassmeier , I. Ilyin

We introduce a framework that enables efficient sampling from learned probability distributions for MRI reconstruction. Different from conventional deep learning-based MRI reconstruction techniques, samples are drawn from the posterior…

Machine Learning · Computer Science 2023-07-21 Guanxiong Luo , Moritz Blumenthal , Martin Heide , Martin Uecker

Speden is a computer program that reconstructs the electron density of single particles from their x-ray diffraction patterns, using a single-particle adaptation of the Holographic Method in crystallography. (Szoke, A., Szoke, H., and…

Extrapolation is a generic problem in physics and mathematics: how to use asymptotic data in one parametric regime to learn about the behavior of a function in another parametric regime. For example: extending weak coupling expansions to…

High Energy Physics - Theory · Physics 2019-10-25 Ovidiu Costin , Gerald V. Dunne

Hydrogen recombination is one of the most important atomic processes in many astrophysical objects such as Type II supernova (SN~II) atmospheres, the high redshift universe during the cosmological recombination era, and H II regions in the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Soma De , E. Baron , Peter H. Hauschildt

Common imaging techniques for detecting structural defects typically require sampling at more than twice the spatial frequency to achieve a target resolution. This study introduces a novel framework for imaging structural defects using…

Signal Processing · Electrical Eng. & Systems 2024-12-03 Wei-Chen Li , Chun-Yeon Lin

This contribution addresses the problem of image reconstruction of radioactivity distribution for which the available information arises from several classes of data, each associated with a specific combination of detections. We introduce a…

Applications · Statistics 2023-09-12 Mehdi Latif , Jérôme Idier , Thomas Carlier , Simon Stute

In a non supervised Bayesian estimation approach for inverse problems in imaging systems, one tries to estimate jointly the unknown image pixels $f$ and the hyperparameters $\theta$ given the observed data $g$ and a model $M$ linking these…

Mathematical Physics · Physics 2009-04-28 Ali Mohammad-Djafari

To reduce scanning time and/or improve spatial/temporal resolution in some MRI applications, parallel MRI (pMRI) acquisition techniques with multiple coils acquisition have emerged since the early 1990s as powerful 3D imaging methods that…

Optimization and Control · Mathematics 2009-09-03 Lotfi Chaari , Jean-Christophe Pesquet , Philippe Ciuciu , Amel Benazza-Benyahia

In magnetoencephalography (MEG) the conventional approach to source reconstruction is to solve the underdetermined inverse problem independently over time and space. Here we present how the conventional approach can be extended by…

The following electromagnetism (EM) inverse problem is addressed. It consists in estimating local radioelectric properties of materials recovering an object from global EM scattering measurements, at various incidences and wave frequencies.…

Applications · Statistics 2015-06-12 François Giraud , Pierre Minvielle , Pierre Del Moral

Inversion codes are numerical tools used for the inference of physical properties from the observations. Despite their success, the quality of current spectropolarimetric observations and those expected in the near future presents a…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. Asensio Ramos , J. de la Cruz Rodriguez

Recently, multiple formulations of vision problems as probabilistic inversions of generative models based on computer graphics have been proposed. However, applications to 3D perception from natural images have focused on low-dimensional…

Computer Vision and Pattern Recognition · Computer Science 2014-07-08 Tejas D. Kulkarni , Vikash K. Mansinghka , Pushmeet Kohli , Joshua B. Tenenbaum

Masked autoencoders (MAE) have shown great promise in medical image classification. However, the random masking strategy employed by traditional MAEs may overlook critical areas in medical images, where even subtle changes can indicate…

Computer Vision and Pattern Recognition · Computer Science 2026-05-27 Joao Batista Florindo , Viviane de Moura

In image reconstruction there are techniques that use analytical formulae for the Radon transform to recover an image from a continuum of data. In practice, however, one has only discrete data available. Thus one often resorts to sampling…

Functional Analysis · Mathematics 2011-08-30 Isaac Pesenson , Eric Grinberg

We present a theoretical investigation of the radiative recombination of twisted Bessel electrons with initially hydrogen-like (finally helium-like) heavy ions. In our study, we focus especially on the linear polarization of x-ray photons…

Atomic Physics · Physics 2021-09-08 Anna V. Maiorova , Anton A. Peshkov , Andrey Surzhykov

Wavelet functions allow the sparse and efficient representation of a signal at different scales. Recently the application of wavelets to the denoising of maps of cosmic microwave background (CMB) fluctuations has been proposed. The…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , A. N. Lasenby

Purpose: For quantitative susceptibility mapping (QSM), the lack of ground-truth in clinical settings makes it challenging to determine suitable parameters for the dipole inversion. We propose a probabilistic Bayesian approach for QSM with…

Image and Video Processing · Electrical Eng. & Systems 2023-06-01 Shuai Huang , James J. Lah , Jason W. Allen , Deqiang Qiu

We introduce a probabilistic approach to ptychographic reconstruction in computational imaging. Ptychography is an imaging method where the complex amplitude of an object is estimated from a sequence of diffraction measurements. We…

Applications · Statistics 2025-04-09 Hajime Ueda , Shun Katakami , Masato Okada