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In a mixed generalized linear model, the goal is to learn multiple signals from unlabeled observations: each sample comes from exactly one signal, but it is not known which one. We consider the prototypical problem of estimating two…

Statistics Theory · Mathematics 2026-01-12 Yihan Zhang , Marco Mondelli , Ramji Venkataramanan

Accurate spectral analysis of high-energy astrophysical sources often relies on comparing observed data to incident spectral models convolved with the instrument response. However, for Gamma-Ray Bursts and other high-energy transient events…

During the past years several variance reduction techniques for Monte Carlo electron transport have been developed in order to reduce the electron computation time transport for absorbed dose distribution. We have implemented the Macro…

Medical Physics · Physics 2009-11-13 L. A. Perles , A. de Almeida

The montecarlo method, which is quite commonly used to solve maximum entropy problems in statistical physics, can actually be used to solve inverse problems in a much wider context. The probability distribution which maximizes entropy can…

Statistical Mechanics · Physics 2007-05-23 Jan Naudts

Since the universe is not transparent to gamma rays with energies above around one hundred GeV, it is necessary to account for the interaction of high-energy photons with intergalactic radiation fields in order to model gamma-ray…

High Energy Astrophysical Phenomena · Physics 2025-05-16 Antonio Capanema , Carlos Blanco

Radio weak lensing, while a highly promising complementary probe to optical weak lensing, will require incredible precision in the measurement of galaxy shape parameters. In this paper, we extend the Bayesian Inference for Radio…

Instrumentation and Methods for Astrophysics · Physics 2018-11-05 M. Rivi , M. Lochner , S. T. Balan , I. Harrison , F. B. Abdalla

The monitoring of Cs-137 in seawater using scintillation detector relies on the spectrum analysis method to extract the Cs-137 concentration. And when in poor statistic situation, the calculation result of the traditional net peak area…

Instrumentation and Detectors · Physics 2021-08-20 Wenhan Dai , Zhi Zeng , Daowei Dou , Hao Ma , Jianping Chen , Junli Li , Hui Zhang

One of the challenges in hyperspectral data analysis is the presence of mixed pixels. Mixed pixels are the result of low spatial resolution of hyperspectral sensors. Spectral unmixing methods decompose a mixed pixel into a set of endmembers…

Computer Vision and Pattern Recognition · Computer Science 2015-06-05 Roozbeh Rajabi , Hassan Ghassemian

In an ideal germanium detector, fully-absorbed monoenergetic gamma-rays will appear in the measured spectrum as a narrow peak, broadened into a Gaussian of width determined only by the statistical properties of charge cloud generation and…

Instrumentation and Methods for Astrophysics · Physics 2023-08-03 Steven E. Boggs , Sean N. Pike

Despite the rapid development of computational hardware, the treatment of large and high dimensional data sets is still a challenging problem. This paper provides a twofold contribution to the topic. First, we propose a Gaussian Mixture…

The representation of subgrid-scale orography is a challenge in the physical parameterization of orographic gravity-wave sources in weather forecasting. A significant hurdle is encoding as much physical information with as simple a…

Atmospheric and Oceanic Physics · Physics 2025-01-16 Ray Chew , Stamen Dolaptchiev , Maja-Sophie Wedel , Ulrich Achatz

We present a Monte Carlo rendering framework for the physically-accurate simulation of speckle patterns arising from volumetric scattering of coherent waves. These noise-like patterns are characterized by strong statistical properties, such…

Optics · Physics 2019-01-23 Chen Bar , Marina Alterman , Ioannis Gkioulekas , Anat Levin

This paper presents a multi-band image fusion algorithm based on unsupervised spectral unmixing for combining a high-spatial low-spectral resolution image and a low-spatial high-spectral resolution image. The widely used linear observation…

Computer Vision and Pattern Recognition · Computer Science 2016-11-03 Qi Wei , Jose Bioucas-Dias , Nicolas Dobigeon , Jean-Yves Tourneret , Marcus Chen , Simon Godsill

The validation of a previous work on the optimization of material discrimination in spectral x-ray imaging is reported. Using Monte Carlo simulations based on the BEAMnrc package, material decomposition was performed on the projection…

Medical Physics · Physics 2015-06-18 Syen J. Nik , Rune S. Thing , Richard Watts , Tony Dale , Bryn Currie , Juergen Meyer

With several proposed MeV gamma-ray telescopes on the horizon, it is of paramount importance to perform accurate calculations of gamma-ray spectra expected from sub-GeV dark matter annihilation and decay. We present hazma, a python package…

High Energy Physics - Phenomenology · Physics 2020-02-05 Adam Coogan , Logan Morrison , Stefano Profumo

Hard X-ray spectra in solar flares provide knowledge of the electron spectrum that results from acceleration and propagation in the solar atmosphere. However, the inference of the electron spectra from solar X-ray spectra is an ill-posed…

Astrophysics · Physics 2009-11-10 E. P. Kontar , M. Piana , A. M. Massone , A. G. Emslie , J. C. Brown

A method to determine the gamma correction curves for displays is presented. An empirical model is first constructed from exhaustive measurements of a few representative units. The model parameters for the remaining units are then fitted…

Optics · Physics 2014-12-11 Jani Isohanni , Robert Piche

Graph-based multi-view spectral clustering methods have achieved notable progress recently, yet they often fall short in either oversimplifying pairwise relationships or struggling with inefficient spectral decompositions in…

Machine Learning · Computer Science 2025-11-14 Murong Yang , Shihui Ying , Xin-Jian Xu , Yue Gao

This paper concerns the approximation of smooth, high-dimensional functions from limited samples using polynomials. This task lies at the heart of many applications in computational science and engineering - notably, some of those arising…

Numerical Analysis · Mathematics 2023-11-07 Ben Adcock , Simone Brugiapaglia

This article considers stochastic algorithms for efficiently solving a class of large scale non-linear least squares (NLS) problems which frequently arise in applications. We propose eight variants of a practical randomized algorithm where…

Numerical Analysis · Mathematics 2015-01-27 Farbod Roosta-Khorasani , Gábor J. Székely , Uri Ascher