English
Related papers

Related papers: A Method for Gamma-Ray Energy Spectrum Inversion a…

200 papers

We present a novel approach to the regression of quantum mechanical energies based on a scattering transform of an intermediate electron density representation. A scattering transform is a deep convolution network computed with a cascade of…

Machine Learning · Computer Science 2016-05-23 Matthew Hirn , Nicolas Poilvert , Stéphane Mallat

Instrumental variable analysis is a powerful tool for estimating causal effects when randomization or full control of confounders is not possible. The application of standard methods such as 2SLS, GMM, and more recent variants are…

Machine Learning · Statistics 2020-06-08 Andrew Bennett , Nathan Kallus , Tobias Schnabel

In this study, we explore the potential of machine learning for modeling molecular electronic spectral intensities as a continuous function in a given wavelength range. Since presently available chemical space datasets provide excitation…

Chemical Physics · Physics 2022-08-02 Prakriti Kayastha , Sabyasachi Chakraborty , Raghunathan Ramakrishnan

We analyzed data obtained by the SPI telescope onboard the INTEGRAL observatory to search for short transient events with a duration from 1 ms to a few tens of seconds. An algorithm for identifying gamma-ray events against the background of…

High Energy Astrophysical Phenomena · Physics 2015-06-19 P. Yu. Minaev , A. S. Pozanenko , S. V. Molkov , S. A. Grebenev

SPI-ACS/INTEGRAL is one of the most sensitive orbital gamma-ray detectors in energy range above 80 keV. Since 2002 it registered several thousands of gamma-ray bursts, including the bursts associated with LIGO-Virgo gravitational wave…

High Energy Astrophysical Phenomena · Physics 2023-08-22 P. Yu. Minaev , A. S. Pozanenko

This work introduces two Monte Carlo (MC)-based sampling methods, known as line sampling and subset simulation, to improve the performance of standard MC analyses in the context of asteroid impact risk assessment. Both techniques sample the…

Earth and Planetary Astrophysics · Physics 2020-09-28 Matteo Romano , Matteo Losacco , Camilla Colombo , Pierluigi Di Lizia

The unfolding problem in particle physics is to make inferences about the true particle spectrum based on smeared observations from a detector. This is an ill-posed inverse problem, where small changes in the smeared distribution can lead…

High Energy Physics - Experiment · Physics 2026-03-23 Huanbiao Zhu , Andrea Carlo Marini , Mikael Kuusela , Larry Wasserman

The paper considers an inverse problem of reconstructing the spatially distributed complex dielectric permittivity function using backscattered data of the electric field in the frequency domain. We develop iterative algorithm for…

Medical Physics · Physics 2024-10-29 Larisa Beilina , Anders Eriksson , Noora Neittaanmäki

Finite element model updating utilizing frequency response functions as inputs is an important procedure in structural analysis, design and control. This paper presents a highly efficient framework that is built upon Gaussian process…

Computational Engineering, Finance, and Science · Computer Science 2020-08-26 Kai Zhou , Jiong Tang

We present the time integrated and time resolved spectral analysis of a sample of bright bursts selected from the BATSE archive. We fitted four different spectral models to the time integrated and time resolved spectra of the flux pulses.…

Astrophysics · Physics 2009-11-07 G. Ghirlanda , A. Celotti , G. Ghisellini

The variable activity of a gamma-ray burst (GRB) source is thought to be correlated with its absolute peak luminosity - a relation that, if confirmed, can be used to derive an independent estimate of the redshift of a GRB. We find that…

Astrophysics · Physics 2009-11-07 Nicole M. Lloyd-Ronning , Enrico Ramirez-Ruiz

Diffusion models (DMs) have emerged as powerful tools for modeling complex data distributions and generating realistic new samples. Over the years, advanced architectures and sampling methods have been developed to make these models…

Machine Learning · Computer Science 2025-12-11 Roi Benita , Michael Elad , Joseph Keshet

In Single Photon Emission Computed Tomography (SPECT), 3D images usually reconstructed by performing a set of bidimensional (2D) analytical or iterative reconstructions can also be reconstructed using an iterative reconstruction algorithm…

Instrumentation and Detectors · Physics 2007-05-23 Z. El Bitar , I. Buvat , V. Breton , D. Lazaro , D. Hill

We study a spectral initialization method that serves a key role in recent work on estimating signals in nonconvex settings. Previous analysis of this method focuses on the phase retrieval problem and provides only performance bounds. In…

Information Theory · Computer Science 2019-07-23 Yue M. Lu , Gen Li

The Large Area Telescope (LAT) onboard the Fermi satellite is exploring the gamma-ray sky in the energy range above 20MeV. We have developed a method to reconstruct the energy spectra of the gamma rays detected by the Fermi LAT instrument…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 M. N. Mazziotta

In regimes of low signal strengths and therefore a small signal-to-noise ratio, standard data analysis methods often fail to accurately estimate system properties. We present a method based on Monte Carlo simulations to effectively restore…

We consider the topic of multivariate regression on manifold-valued output, that is, for a multivariate observation, its output response lies on a manifold. Moreover, we propose a new regression model to deal with the presence of grossly…

Machine Learning · Statistics 2017-09-12 Xiaowei Zhang , Xudong Shi , Yu Sun , Li Cheng

A Transformer-based deep direct sampling method is proposed for electrical impedance tomography, a well-known severely ill-posed nonlinear boundary value inverse problem. A real-time reconstruction is achieved by evaluating the learned…

Machine Learning · Computer Science 2023-03-07 Ruchi Guo , Shuhao Cao , Long Chen

We have examined cutoffs and pile-ups due to various processes in the spectra of particles produced by shock acceleration, and found that, even in the absence of energy losses, the shape of the spectrum of accelerated particles at energies…

Astrophysics · Physics 2011-05-12 R. J. Protheroe , Todor Stanev

Indirect imaging problems in biomedical optics generally require repeated evaluation of forward models of radiative transport, for which Monte Carlo is accurate yet computationally costly. We develop a novel approach to reduce this…

Computational Physics · Physics 2020-07-10 Callum M. Macdonald , Simon Arridge , Samuel Powell