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We describe an optimal signal extraction process for imaging X-ray polarimetry using an ensemble of deep neural networks. The initial photo-electron angle, used to recover the polarization, has errors following a von Mises distribution.…

Instrumentation and Methods for Astrophysics · Physics 2021-10-20 A. L. Peirson , R. W. Romani

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

Instrumentation and Methods for Astrophysics · Physics 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

The cryo-electron microscopy (Cryo-EM) becomes popular for macromolecular structure determination. However, the 2D images which Cryo-EM detects are of high noise and often mixed with multiple heterogeneous conformations or contamination,…

Image and Video Processing · Electrical Eng. & Systems 2022-02-22 Hanlin Gu , Yin Xian , Ilona Christy Unarta , Yuan Yao

Modeling of microlensing events poses computational challenges for the resolution of the lens equation and the high dimensionality of the parameter space. In particular, numerical noise represents a severe limitation to fast and efficient…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 V. Bozza , V. Saggese , G. Covone , P. Rota , J. Zhang

Expectation maximization (EM) algorithm is to find maximum likelihood solution for models having latent variables. A typical example is Gaussian Mixture Model (GMM) which requires Gaussian assumption, however, natural images are highly…

Machine Learning · Computer Science 2018-12-04 Wentian Zhao , Shaojie Wang , Zhihuai Xie , Jing Shi , Chenliang Xu

Entropy minimization (EM) is frequently used to increase the accuracy of classification models when they're faced with new data at test time. EM is a self-supervised learning method that optimizes classifiers to assign even higher…

Computer Vision and Pattern Recognition · Computer Science 2024-05-14 Ori Press , Ravid Shwartz-Ziv , Yann LeCun , Matthias Bethge

VLBI at millimeter wavelengths (mm-VLBI) allows the detailed imaging of compact galactic and extragalactic radio sources with micro-arcsecond scale resolution, unaccessible by other observing techniques. Here we discuss the scientific…

Astrophysics · Physics 2007-05-23 T. P Krichbaum , A. Witzel , J. A. Zensus

The embedded atom method (EAM) is one of the most widely used many-body, short-range potentials in molecular dynamics simulations, particularly for metallic systems. To enhance the efficiency of calculating these short-range interactions,…

Materials Science · Physics 2025-03-25 Jieqiong Zhang , Jizu Huang , Zihao Yang

We present a maximum-entropy method (MEM) and `Mexican Hat' wavelet (MHW) joint analysis to recover the different components of the microwave sky from simulated observations by the ESA Planck satellite in a small patch of the sky. This…

In this paper, an enhanced Virtual Element Method (VEM) formulation is proposed for plane elasticity. It is based on the improvement of the strain representation within the element, without altering the degree of the displacement…

Numerical Analysis · Mathematics 2021-02-24 A. M. D'Altri , S. de Miranda , L. Patruno , E. Sacco

The purpose of this note is to show how the method of maximum entropy in the mean (MEM) may be used to improve parametric estimation when the measurements are corrupted by large level of noise. The method is developed in the context on a…

Machine Learning · Computer Science 2021-08-23 Henryk Gzyl , Enrique ter Horst

We develop an all-hex meshing strategy for the interstitial space in beds of densely packed spheres that is tailored to turbulent flow simulations based on the spectral element method (SEM). The SEM achieves resolution through elevated…

Computational Engineering, Finance, and Science · Computer Science 2021-06-03 Yu-Hsiang Lan , Paul Fischer , Elia Merzari , Misun Min

We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Elina Keihänen , Kimmo Kiiveri , Hannu Kurki-Suonio , Martin Reinecke

Large language models (LLMs) exhibit impressive natural language capabilities but suffer from hallucination -- generating content ungrounded in the realities of training data. Recent work has focused on decoding techniques to improve…

Computation and Language · Computer Science 2024-04-16 Souvik Das , Lifeng Jin , Linfeng Song , Haitao Mi , Baolin Peng , Dong Yu

Blind deconvolution has made significant progress in the past decade. Most successful algorithms are classified either as Variational or Maximum a-Posteriori ($MAP$). In spite of the superior theoretical justification of variational…

Computer Vision and Pattern Recognition · Computer Science 2014-06-17 Dilip Krishnan , Joan Bruna , Rob Fergus

Radio observations with Very Long Baseline Interferometry (VLBI) provide the highest resolution in astronomy. Combining earth-bound with space-based telescopes and advancing the observations to mm-wavelengths increases the resolution even…

Astrophysics · Physics 2007-05-23 J. A. Zensus , T. P. Krichbaum , S. Britzen

This paper introduces a multiscale maximum entropy (MSME) algorithm for image restoration of the Hard X-ray Modulation Telescope (HXMT), which is a collimated scan X-ray satellite mainly devoted to a sensitive all-sky survey and pointed…

Instrumentation and Methods for Astrophysics · Physics 2016-06-03 Ju Guan , Li-Ming Song , Zhuo-Xi Huo

The Finite element method (FEM) has long served as the computational backbone for topology optimization (TO). However, for designing structures undergoing large deformations, conventional FEM-based TO often exhibits numerical instabilities…

Computational Engineering, Finance, and Science · Computer Science 2026-03-17 Rahul Kumar Padhy , Aaditya Chandrasekhar , Krishnan Suresh

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…

In this paper, we introduce a variational Bayesian algorithm (VBA) for image blind deconvolution. Our generic framework incorporates smoothness priors on the unknown blur/image and possible affine constraints (e.g., sum to one) on the blur…

Computer Vision and Pattern Recognition · Computer Science 2021-10-15 Yunshi Huang , Emilie Chouzenoux , Jean-Christophe Pesquet
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