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Related papers: Modeling X-ray photon pile-up with a normalizing f…

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We present a novel, purely affinity-based natural image matting algorithm. Our method relies on carefully defined pixel-to-pixel connections that enable effective use of information available in the image. We control the information flow…

Computer Vision and Pattern Recognition · Computer Science 2019-04-15 Yağız Aksoy , Tunç Ozan Aydın , Marc Pollefeys

Proper regularization is crucial in inverse problems to achieve high-quality reconstruction, even with an ill-conditioned measurement system. This is particularly true for three-dimensional photoacoustic tomography, which is computationally…

Optimization and Control · Mathematics 2024-09-26 Chao Wang , Alexandre H. Thiery

Simulated events are key ingredients in almost all high-energy physics analyses. However, imperfections in the simulation can lead to sizeable differences between the observed data and simulated events. The effects of such mismodelling on…

High Energy Physics - Phenomenology · Physics 2024-09-09 Caio Cesar Daumann , Mauro Donega , Johannes Erdmann , Massimiliano Galli , Jan Lukas Späh , Davide Valsecchi

In many scientific applications, the target probability distribution cannot be evaluated in closed form or sampled from directly. Instead, it can often be decomposed into multiple components, some of which are accessible only through…

Methodology · Statistics 2026-03-10 Roxana Darvishi , David C. Stenning , Ted von Hippel , Owen G. Ward

X-ray scattering patterns from emerging single particle experiments have commonly many missing or contaminated pixels. This complicates different analyses including projections on Fourier or other basis functions (for noise suppression,…

Data Analysis, Statistics and Probability · Physics 2014-11-19 Aliakbar Jafarpour

The systematic discovery of outflows in the optical spectra of low-mass X-ray binaries opened a new avenue for the study of the outburst evolution in these extreme systems. However, the efficient detection of such features in a continuously…

High Energy Astrophysical Phenomena · Physics 2023-06-28 D. Mata Sánchez , T. Muñoz-Darias , J. Casares , M. Huertas-Company , G. Panizo-Espinar

We propose a method for estimating the posterior distribution of a standard geostatistical model. After choosing the model formulation and specifying a prior, we use normal mixture densities to approximate the posterior distribution. The…

Methodology · Statistics 2014-09-10 Zepu Zhang

We develop a Monte-Carlo code to compute the Compton scattered X-ray flux arising from a hot inner flow which undergoes Lense-Thirring precession. The hot flow intercepts seed photons from an outer truncated thin disk. A fraction of the…

High Energy Astrophysical Phenomena · Physics 2018-05-23 Bei You , Michal Bursa , Piotr T. Życki

An event-based maximum likelihood method for handling X-ray polarimetry data is extended to include the effects of background and nonuniform sampling of the possible position angle space. While nonuniform sampling in position angle space…

Instrumentation and Methods for Astrophysics · Physics 2024-02-06 Herman L. Marshall

We have searched for extended X-ray sources in the ROSAT PSPC archive using the Voronoi Tesslation and Percolation algorithm (VTP). This algorithm detects all significant sources regardless of shape or size, and is particularly suited to…

Astrophysics · Physics 2007-05-23 L. R. Jones , C. A. Scharf , H. Ebeling , E. Perlman , M. Malkan , G. Wegner

The automatic classification of X-ray detections is a necessary step in extracting astrophysical information from compiled catalogs of astrophysical sources. Classification is useful for the study of individual objects, statistics for…

Instrumentation and Methods for Astrophysics · Physics 2024-01-30 Víctor Samuel Pérez-Díaz , Juan Rafael Martínez-Galarza , Alexander Caicedo , Raffaele D'Abrusco

Sampling from unnormalized densities is analogous to the generative modeling problem, but the target distribution is defined by a known energy function instead of data samples. Because evaluating the energy function is often costly, a…

Machine Learning · Computer Science 2026-05-06 Aaron Havens , Brian Karrer , Neta Shaul

We present a likelihood-free probabilistic inversion method based on normalizing flows for high-dimensional inverse problems. The proposed method is composed of two complementary networks: a summary network for data compression and an…

Machine Learning · Computer Science 2024-12-30 Jice Zeng , Yuanzhe Wang , Alexandre M. Tartakovsky , David Barajas-Solano

In recent years, autoregressive models have had a profound impact on the description of astronomical time series as the observation of a stochastic process. These methods have advantages compared with common Fourier techniques concerning…

Astrophysics · Physics 2009-10-28 Michael Koenig , Jens Timmer

In inverse problems, we often have access to data consisting of paired samples $(x,y)\sim p_{X,Y}(x,y)$ where $y$ are partial observations of a physical system, and $x$ represents the unknowns of the problem. Under these circumstances, we…

Machine Learning · Statistics 2020-07-17 Ali Siahkoohi , Gabrio Rizzuti , Philipp A. Witte , Felix J. Herrmann

Unbinned likelihood fits aim at maximizing the information one can extract from experimental data, yet their application in realistic statistical analyses is often hindered by the computational cost of profiling systematic uncertainties.…

High Energy Physics - Phenomenology · Physics 2026-02-16 Davide Valsecchi , Mauro Donegà , Rainer Wallny

Estimating the expectation of a real-valued function of a random variable from sample data is a critical aspect of statistical analysis, with far-reaching implications in various applications. Current methodologies typically assume…

Machine Learning · Computer Science 2026-02-18 Paweł Lorek , Rafał Nowak , Rafał Topolnicki , Tomasz Trzciński , Maciej Zięba , Aleksandra Krystecka

We report a pile-up rejection technique based on X-ray absorption concept of Beer-Lambert law for measuring true events in the pile-up region. We have detected a 10^4 times weaker peak in the pile-up region. This technique also enables one…

Instrumentation and Detectors · Physics 2016-01-20 Gaurav Sharma , Deepak Swami , Basu Kumar , Nitin Kumar Puri , Tapan Nandi

With the adoption of powerful machine learning methods in medical image analysis, it is becoming increasingly desirable to aggregate data that is acquired across multiple sites. However, the underlying assumption of many analysis techniques…

Computer Vision and Pattern Recognition · Computer Science 2018-11-21 Daniel C. Castro , Ben Glocker

We provide a framework for solving inverse problems with diffusion models learned from linearly corrupted data. Firstly, we extend the Ambient Diffusion framework to enable training directly from measurements corrupted in the Fourier…

Computer Vision and Pattern Recognition · Computer Science 2025-04-23 Asad Aali , Giannis Daras , Brett Levac , Sidharth Kumar , Alexandros G. Dimakis , Jonathan I. Tamir