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A solution of the radiative-transfer problem in arbitrary velocity fields introduced in a previous paper, has limitations in its applicability. For large-scale applications, the methods described also require large memory sets that are…

Solar and Stellar Astrophysics · Physics 2009-09-24 S. Knop , P. H. Hauschildt , E. Baron

We present an implementation of an adaptive ray tracing (ART) module in the Athena hydrodynamics code that accurately and efficiently handles the radiative transfer involving multiple point sources on a three-dimensional Cartesian grid. We…

Instrumentation and Methods for Astrophysics · Physics 2017-12-27 Jeong-Gyu Kim , Woong-Tae Kim , Eve C. Ostriker , M. Aaron Skinner

Aims. We present MCFOST-art, a new non-local thermodynamic equilibrium radiative transfer solver for multilevel atomic systems. The code is embedded in the 3D radiative transfer code MCFOST and is compatible with most of the MCFOST modules.…

Solar and Stellar Astrophysics · Physics 2021-03-03 B. Tessore , C. Pinte , J. Bouvier , F. Ménard

Thermal radiative transfer (TRT) is an essential piece of physics in inertial confinement fusion, high-energy density physics, astrophysics etc. The physical models of this type of problem are defined by strongly coupled differential…

Numerical Analysis · Mathematics 2025-08-06 Dmitriy Y. Anistratov , Terry S. Haut

Three-dimensional (3D) medical image enhancement, including denoising and super-resolution, is critical for clinical diagnosis in CT, PET, and MRI. Although diffusion models have shown remarkable success in 2D medical imaging, scaling them…

Computer Vision and Pattern Recognition · Computer Science 2026-04-21 Hongxu Jiang , Fei Li , Boxiao Yu , Ying Zhang , Kaleb Smith , Kuang Gong , Wei Shao

The concept of Dielectric Laser Acceleration (DLA) provides highest gradients among non-plasma particle accelerators. However, stable beam transport and staging have not been shown experimentally yet. We present a scheme that confines the…

Accelerator Physics · Physics 2018-11-28 Uwe Niedermayer , Thilo Egenolf , Oliver Boine-Frankenheim , Peter Hommelhoff

The ability of widely distributed radar systems to capture diverse spatial scattering properties substantially improves radar imaging performance. Traditional imaging methods leverage regularized optimization techniques to reconstruct…

Signal Processing · Electrical Eng. & Systems 2023-07-18 Ahmed Murtada , Bhavani Shankar Mysore Rama Rao , Udo Schroeder

We present a new code for solving the molecular and atomic excitation and radiation transfer problem in a molecular gas and predicting emergent spectra. This code works in arbitrary three dimensional geometry using unstructured Delaunay…

Solar and Stellar Astrophysics · Physics 2015-05-19 C. Brinch , M. R. Hogerheijde

The kernel-independent fast multipole method (KIFMM) proposed in [1] is of almost linear complexity. In the original KIFMM the time-consuming M2L translations are accelerated by FFT. However, when more equivalent points are used to achieve…

Numerical Analysis · Computer Science 2015-03-19 Yanchuang Cao , Lihua Wen , Junjie Rong

We present a numerical implementation of radiative transfer based on an explicitly photon-conserving advection scheme, where radiative fluxes over the cell interfaces of a structured or unstructured mesh are calculated with a second-order…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Margarita Petkova , Volker Springel

We investigate transient radiation processes in the non-linear superradiance (SR) regime of the Doppler broadened Maxwell-Bloch equations when the velocity distribution is of total bandwidth greatly exceeding that of the transient process…

We have developed a real-space method to correct distortion due to thermal drift and piezoelectric actuator nonlinearities on scanning tunneling microscope images using Matlab. The method uses the known structures typically present in…

Instrumentation and Detectors · Physics 2017-02-03 Mitchell P. Yothers , Aaron E. Browder , Lloyd A. Bumm

We introduce {\em vector diffusion maps} (VDM), a new mathematical framework for organizing and analyzing massive high dimensional data sets, images and shapes. VDM is a mathematical and algorithmic generalization of diffusion maps and…

Statistics Theory · Mathematics 2011-02-02 Amit Singer , Hau-tieng Wu

We consider a multi-link diffusion-based molecular communication (MC) system where multiple spatially distributed transmitter (TX)-receiver (RX) pairs establish point-to-point communication links employing the same type of signaling…

Information Theory · Computer Science 2023-09-29 Lukas Brand , Sebastian Lotter , Vahid Jamali , Robert Schober , Maximilian Schäfer

We discuss work toward developing a 2.5D non-LTE radiative transfer code. Our code uses the short characteristic method with modifications to handle realistic 3D wind velocities. We also designed this code for parallel computing facilities…

Astrophysics · Physics 2007-05-23 J. Zsargo , D. J. Hillier , L. N. Georgiev

We present an algorithm for two-dimensional radiative transfer in axisymmetric, circumstellar media. The formal integration of the transfer equation is performed by a generalization of the short characteristics (SC) method to spherical…

Astrophysics · Physics 2007-05-23 C. P. Dullemond , R. Turolla

The solar atmosphere is diagnosed by solving the polarized radiative transfer problem for plasmas in Non-Local Thermodynamic Equilibrium (NLTE). A key challenge in multidimensional NLTE diagnosis is to integrate efficiently the radiative…

Solar and Stellar Astrophysics · Physics 2025-03-31 E. S. Carlin , S. Blanes , F. Casas

In this paper we consider speedup potential of morphological image filtering on ARM processors. Morphological operations are widely used in image analysis and recognition and their speedup in some cases can significantly reduce overall…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-02-24 Elena Limonova , Arseny Terekhin , Dmitry Nikolaev , Vladimir Arlazarov

Resonance spectral lines such as H I Ly {\alpha}, Mg II h&k, and Ca II H&K that form in the solar chromosphere are influenced by the effects of 3D radiative transfer as well as partial redistribution (PRD). So far no one has modeled these…

Solar and Stellar Astrophysics · Physics 2016-12-28 Andrii V. Sukhorukov , Jorrit Leenaarts

This paper presents nonlinear iterative methods for the fundamental thermal radiative transfer (TRT) model defined by the time-dependent multifrequency radiative transfer (RT) equation and the material energy balance (MEB) equation. The…

Numerical Analysis · Mathematics 2024-09-24 Dmitriy Y. Anistratov