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The use of deep learning has successfully solved several problems in the field of medical imaging. Deep learning has been applied to the CT denoising problem successfully. However, the use of deep learning requires large amounts of data to…

Image and Video Processing · Electrical Eng. & Systems 2022-04-04 Mayank Patwari , Ralf Gutjahr , Rainer Raupach , Andreas Maier

In this paper, we address the problem of denoising images degraded by Poisson noise. We propose a new patch-based approach based on best linear prediction to estimate the underlying clean image. A simplified prediction formula is derived…

Computer Vision and Pattern Recognition · Computer Science 2018-03-02 Milad Niknejad , Mario A. T. Figueiredo

One of the primary sources of uncertainties in modeling the cosmic-shear power spectrum on small scales is the effect of baryonic physics. Accurate cosmology for Stage-IV surveys requires knowledge of the matter power spectrum deep in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Maria G. Moreira , Felipe Andrade-Oliveira , Xiao Fang , Hung-Jin Huang , Elisabeth Krause , Vivian Miranda , Rogerio Rosenfeld , Marko Simonović

We define an optimal basis system into which cosmological observables can be decomposed. The basis system can be optimised for a specific cosmological model or for an ensemble of models, even if based on drastically different physical…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-21 M. Maturi , C. Mignone

Covariance matrices are essential cosmological probes of fundamental physics, providing information on numerous fundamental physical parameters and varying with any change in the underlying cosmology. However, this cosmology dependence,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-21 Theodore Steele , Robert Smith , Roisin O'Connor

The low-complexity assumption in linear systems can often be expressed as rank deficiency in data matrices with generalized Hankel structure. This makes it possible to denoise the data by estimating the underlying structured low-rank…

Systems and Control · Electrical Eng. & Systems 2021-11-10 Mingzhou Yin , Roy S. Smith

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

Astrophysics · Physics 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

Deep learning had already demonstrated its power in medical images, including denoising, classification, segmentation, etc. All these applications are proposed to automatically analyze medical images beforehand, which brings more…

Image and Video Processing · Electrical Eng. & Systems 2020-11-05 Shao-Cheng Wen , Yu-Jen Chen , Zihao Liu , Wujie Wen , Xiaowei Xu , Yiyu Shi , Tsung-Yi Ho , Qianjun Jia , Meiping Huang , Jian Zhuang

The Hubble parameter, $H(z)$, plays a crucial role in understanding the expansion history of the universe and constraining the Hubble constant, $\mathrm{H}_0$. The Cosmic Chronometers (CC) method provides an independent approach to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-15 Jing Niu , Peng He , Tong-Jie Zhang

Covariance matrix estimation is a persistent challenge for cosmology. We focus on a class of model covariance matrices that can be generated with high accuracy and precision, using a tiny fraction of the computational resources that would…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Ross O'Connell , Daniel J. Eisenstein

We seek to improve estimates of the power spectrum covariance matrix from a limited number of simulations by employing a novel statistical technique known as shrinkage estimation. The shrinkage technique optimally combines an empirical…

Astrophysics · Physics 2009-11-13 Adrian C. Pope , István Szapudi

Hyperspectral images (HSIs) are susceptible to various noise factors leading to the loss of information, and the noise restricts the subsequent HSIs object detection and classification tasks. In recent years, learning-based methods have…

Neural and Evolutionary Computing · Computer Science 2020-08-18 Yuqiao Liu , Yanan Sun , Bing Xue , Mengjie Zhang

We present a new method, called $x$-cut cosmic shear, which optimally removes sensitivity to poorly modeled scales from the two-point cosmic shear signal. We show that the $x$-cut cosmic shear covariance matrix can be computed from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 Peter L. Taylor , Francis Bernardeau , Eric Huff

The topology and dynamics of the solar chromosphere are greatly affected by the presence of magnetic fields. The magnetic field can be inferred by analyzing polarimetric observations of spectral lines. Polarimetric signals induced by…

Solar and Stellar Astrophysics · Physics 2019-09-11 C. J. Díaz Baso , J. de la Cruz Rodríguez , S. Danilovic

Inference and Estimation in Missing Information (MI) scenarios are important topics in Statistical Learning Theory and Machine Learning (ML). In ML literature, attempts have been made to enhance prediction through precise feature selection…

Machine Learning · Statistics 2017-07-26 Ahmadreza Moradipari , Sina Shahsavari , Ashkan Esmaeili , Farokh Marvasti

In many data analysis applications the following scenario is commonplace: we are given a point set that is supposed to sample a hidden ground truth $K$ in a metric space, but it got corrupted with noise so that some of the data points lie…

Computational Geometry · Computer Science 2017-03-28 Mickaël Buchet , Tamal K. Dey , Jiayuan Wang , Yusu Wang

The accurate computation of the covariance matrix of fitted model parameters is a somewhat neglected task in Statistics. Algorithms are given for computing accurate covariance matrices derived from computing the Hessian matrix by numerical…

Computation · Statistics 2021-05-12 Rose Baker

Like in many other research fields, recent developments in computational imaging have focused on developing machine learning (ML) approaches to tackle its main challenges. To improve the performance of computational imaging algorithms,…

Image and Video Processing · Electrical Eng. & Systems 2024-08-16 Maximilian B. Kiss , Ander Biguri , Carola-Bibiane Schönlieb , K. Joost Batenburg , Felix Lucka

We introduce a new method for estimating the covariance matrix for the galaxy correlation function in surveys of large-scale structure. Our method combines simple theoretical results with a realistic characterization of the survey to…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Ross O'Connell , Daniel Eisenstein , Mariana Vargas , Shirley Ho , Nikhil Padmanabhan

We describe a novel end-to-end approach using Machine Learning to reconstruct the power spectrum of cosmological density perturbations at high redshift from observed quasar spectra. State-of-the-art cosmological simulations of structure…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Maria Han Veiga , Xi Meng , Oleg Y. Gnedin , Nickolay Y. Gnedin , Xun Huan