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Reconstructing 4D or 6D phase space distributions from 1D or 2D measurements is a challenging inverse problem encountered in particle accelerators. Entropy maximization is an established method to incorporate prior information in the…

Accelerator Physics · Physics 2025-08-18 Austin Hoover

Very long baseline interferometry (VLBI) is a technique for imaging celestial radio emissions by simultaneously observing a source from telescopes distributed across Earth. The challenges in reconstructing images from fine angular…

Instrumentation and Methods for Astrophysics · Physics 2016-11-08 Katherine L. Bouman , Michael D. Johnson , Daniel Zoran , Vincent L. Fish , Sheperd S. Doeleman , William T. Freeman

Mixture models with Gamma and or inverse-Gamma distributed mixture components are useful for medical image tissue segmentation or as post-hoc models for regression coefficients obtained from linear regression within a Generalised Linear…

Machine Learning · Statistics 2016-07-27 A. Llera , D. Vidaurre , R. H. R. Pruim , C. F. Beckmann

The recent emergence of deep learning has led to a great deal of work on designing supervised deep semantic segmentation algorithms. As in many tasks sufficient pixel-level labels are very difficult to obtain, we propose a method which…

Computer Vision and Pattern Recognition · Computer Science 2024-04-19 Matthias Schwab , Agnes Mayr , Markus Haltmeier

Exploration is essential for solving complex Reinforcement Learning (RL) tasks. Maximum State-Visitation Entropy (MSVE) formulates the exploration problem as a well-defined policy optimization problem whose solution aims at visiting all…

The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are…

Astrophysics · Physics 2009-11-10 Anisa T. Bajkova

Direct inversion of incomplete visibility samples in VLBI (Very Large Baseline Interferometry) radio telescopes produces images with convolutive artifacts. Since proper analysis and interpretations of astronomical radio sources require a…

Instrumentation and Methods for Astrophysics · Physics 2009-04-06 Andriyan Bayu Suksmono

Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases so too does the atmospheric…

Purpose: Although recent deep energy-based generative models (EBMs) have shown encouraging results in many image generation tasks, how to take advantage of the self-adversarial cogitation in deep EBMs to boost the performance of Magnetic…

Image and Video Processing · Electrical Eng. & Systems 2021-09-10 Yu Guan , Zongjiang Tu , Shanshan Wang , Qiegen Liu , Yuhao Wang , Dong Liang

The proposed next-generation Very Large Array (ngVLA) will enable the imaging of astronomical sources in unprecedented detail by providing an order of magnitude improvement in sensitivity and angular resolution compared with radio…

Solar and Stellar Astrophysics · Physics 2019-10-23 Kazunori Akiyama , Lynn D. Matthews

This paper presents a new method for the reconstruction of weak lensing mass maps. It uses the multiscale entropy concept, which is based on wavelets, and the False Discovery Rate which allows us to derive robust detection levels in wavelet…

Astrophysics · Physics 2009-11-10 Jean-Luc Starck , Sandrine Pires , Alexandre Refregier

The high angular resolution and sensitivity of Very Long Baseline Interferometry (VLBI) offer a unique tool to identify and study active galactic nuclei and star-formation activity over cosmic time. However, despite recent technical…

Astrophysics of Galaxies · Physics 2024-12-05 Célestin Herbé-George , J. P. Mckean , Raffaella Morganti , Jack F. Radcliffe

In this paper, we provide a novel method for the estimation of unknown parameters of the Gaussian Mixture Model (GMM) in Positron Emission Tomography (PET). A vast majority of PET imaging methods are based on reconstruction model that is…

Signal Processing · Electrical Eng. & Systems 2023-06-30 Tomislav Matulić , Damir Seršić

An important linear algebra routine, GEneral Matrix Multiplication (GEMM), is a fundamental operator in deep learning. Compilers need to translate these routines into low-level code optimized for specific hardware. Compiler-level…

Machine Learning · Computer Science 2019-09-25 Huaqing Zhang , Xiaolin Cheng , Hui Zang , Dae Hoon Park

In this paper, we propose a general framework to learn a robust large-margin binary classifier when corrupt measurements, called anomalies, caused by sensor failure might be present in the training set. The goal is to minimize the…

Machine Learning · Computer Science 2016-10-24 Tianpei Xie , Nasser. M. Narabadi , Alfred O. Hero

An iterative method is derived for image reconstruction. Among other attributes, this method allows constraints unrelated to the radiation measurements to be incorporated into the reconstructed image. A comparison is made with the widely…

Computational Physics · Physics 2011-01-06 Clinton DeW. Van Siclen

The Controlled Source Electromagnetic (CSEM) method aims to image electrical resistivity at intermediate depths (0-3 km) for geothermal, mineral, and groundwater exploration. It was developed both as a deeper extension of DC resistivity…

Geophysics · Physics 2026-05-28 F Bretaudeau , S Védrine , C Patzer , B Kim , F Dubois , U Autio , J Kamm , M Darnet

Kernelized maximum-likelihood (ML) expectation maximization (EM) methods have recently gained prominence in PET image reconstruction, outperforming many previous state-of-the-art methods. But they are not immune to the problems of…

Image and Video Processing · Electrical Eng. & Systems 2021-03-05 Shiyao Guo , Yuxia Sheng , Shenpeng Li , Li Chai , Jingxin Zhang

The purpose of this study was to present image reconstruction methods for magnetic particle imaging (MPI) with a field-free-line (FFL) encoding scheme and to propose the use of the maximum likelihood-expectation maximization (ML-EM)…

Medical Physics · Physics 2016-06-13 Kenya Murase

In the context of simulating precision laser interferometers, we compare via several examples two wavefront decomposition methods: the Mode Expansion Method (MEM) and the Gaussian beam decomposition (GBD) for their precision and…