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The integro-differential formulation of the RTE and its solution by iterations on the source has been extended here to handle anisotropic scattering. The iterative part of the method is O(N ln N ), thanks to an efficient use of H-matrices.…

Numerical Analysis · Mathematics 2023-06-12 Olivier Pironneau , Pierre-Henri Tournier

We extend our framework for 3D radiative transfer calculations with a non-local operator splitting methods along (full) characteristics to spherical and cylindrical coordinate systems. These coordinate systems are better suited to a number…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Peter H. Hauschildt , E. Baron

This work addresses the issue of interference generated by co-channel users in downlink multi-antenna multicarrier systems with frequency-packed faster-than-Nyquist (FTN) signaling. The resulting interference stems from an aggressive…

Signal Processing · Electrical Eng. & Systems 2021-07-16 Wallace A. Martins , Symeon Chatzinotas , Björn Ottersten

A finite element method for solving the resonance line transfer problem in moving media is presented. The algorithm works in three spatial dimensions on unstructured grids which are adaptively refined by means of an a posteriori error…

Astrophysics · Physics 2009-11-07 E. Meinkoehn , S. Richling

In optical communications, four-dimensional (4D) modulation formats encode information onto the quadrature components of two arbitrary orthogonal states of polarisation of the optical field. These formats have recently regained attention…

Signal Processing · Electrical Eng. & Systems 2020-12-30 Gabriele Liga , Astrid Barreiro , Hami Rabbani , Alex Alvarado

New implicit and implicit-explicit time-stepping methods for the wave equation in second-order form are described with application to two and three-dimensional problems discretized on overset grids. The implicit schemes are single step,…

Numerical Analysis · Mathematics 2024-04-24 Allison M. Carson , Jeffrey W. Banks , William D. Henshaw , Donald W. Schwendeman

Aiming at a drastic speedup for point-data embeddings at test time, we propose a new framework that uses a pair of multi-layer perceptron (MLP) and look-up table (LUT) to transform point-coordinate inputs into high-dimensional features.…

Computer Vision and Pattern Recognition · Computer Science 2019-12-03 Yusuke Sekikawa , Teppei Suzuki

The cylindrical Taylor Interpolation through FFT (TI-FFT) algorithm for computation of the near-field and far-field in the quasi-cylindrical geometry has been introduced. The modal expansion coefficient of the vector potentials ${\bf F}$…

Signal Processing · Electrical Eng. & Systems 2020-07-06 Shaolin Liao

The possibility of significant systematic errors due to the use of 1D homogeneous atmospheres in lithium-abundance determinations of cool stars motivates a study of non-local-thermodynamic-equilibrium (NLTE) effects on Li I line formation…

Astrophysics · Physics 2009-10-30 Dan Kiselman

Recent efforts in applying implicit networks to solve inverse problems in imaging have achieved competitive or even superior results when compared to feedforward networks. These implicit networks only require constant memory during…

Machine Learning · Computer Science 2024-02-06 Linghai Liu , Shuaicheng Tong , Lisa Zhao

We propose a numerical algorithm that integrates quantum two-level systems (TLSs) into the finite-difference time-domain (FDTD) framework for simulating quantum emitters in arbitrary 3D photonic environments. Conventional methods struggle…

Quantum Physics · Physics 2025-02-27 Qingyi Zhou , S. Ali Hassani Gangaraj , Ming Zhou , Zongfu Yu

Due to strict rate and reliability demands, wireless image transmission remains difficult for both classical layered designs and joint source-channel coding (JSCC), especially under low latency. Diffusion-based generative decoders can…

Machine Learning · Computer Science 2026-01-13 Jingwen Fu , Ming Xiao , Mikael Skoglund , Dong In Kim

The formation of optical fluorescent lines in moving media has not yet been studied in detail, so this work represents a first step in investigating the fluorescence process in different types of macroscopic velocity fields: (a) accelerated…

Solar and Stellar Astrophysics · Physics 2024-09-04 Claude Bertout

We describe a new, faster implicit algorithm for solving the radiation hydrodynamics equations in the flux-limited diffusion approximation for smoothed particle hydrodynamics. This improves on the method elucidated in Whitehouse & Bate by…

Astrophysics · Physics 2009-11-13 Stuart C. Whitehouse , Matthew R. Bate , Joe J. Monaghan

We extend Nuclear Lattice Effective Field Theory (NLEFT) to medium-mass nuclei, and present results for the ground states of alpha nuclei from $^4$He to $^{28}$Si, calculated up to next-to-next-to-leading order (NNLO) in the EFT expansion.…

Nuclear Theory · Physics 2014-04-11 Timo A. Lähde , Evgeny Epelbaum , Hermann Krebs , Dean Lee , Ulf-G. Meißner , Gautam Rupak

In this letter, a fast Fourier transform (FFT)-enhanced low-complexity super-resolution sensing algorithm for near-field source localization with both angle and range estimation is proposed. Most traditional near-field source localization…

Signal Processing · Electrical Eng. & Systems 2024-11-26 Yuxiao Wu , Huizhi Wang , Yong Zeng

Full waveform inversion (FWI) requires an accurate estimation of source signatures. Due to the coupling between the source signatures and the subsurface model, small errors in the former can translate into large errors in the latter. When…

Optimization and Control · Mathematics 2021-05-25 Hossein S. Aghamiry , Frichnel W. Mamfoumbi-Ozoumet , Ali Gholami , Stéphane Operto

Thermal radiative transfer (TRT) presents significant computational challenges due to the stiff, nonlinear coupling between radiation and material energy, particularly in multigroup, high-fidelity transport models. In this work, we develop…

Numerical Analysis · Mathematics 2026-03-24 Samuel Olivier , James S. Warsa , HyeongKae Park

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

We propose in this work a fast numerical algorithm for solving the equation of radiative transfer (ERT) in isotropic media. The algorithm has two steps. In the first step, we derive an integral equation for the angularly averaged ERT…

Numerical Analysis · Mathematics 2019-07-09 Kui Ren , Rongting Zhang , Yimin Zhong
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