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Related papers: An FFT-based approach for Bloch wave analysis: app…

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The Bloch-Torrey equation governs the evolution of the transverse magnetization in diffusion magnetic resonance imaging, where two mechanisms are at play: diffusion of spins (Laplacian term) and their precession in a magnetic field gradient…

Computational Physics · Physics 2021-10-14 Nicolas Moutal , Antoine Moutal , Denis S. Grebenkov

Exploring the vast composition space of multi-component alloys presents a challenging task for both \textit{ab initio} (first principles) and experimental methods due to the time-consuming procedures involved. This ultimately impedes the…

The study of polycrystalline materials requires theoretical and computational techniques enabling multiscale investigations. The amplitude expansion of the phase field crystal model (APFC) allows for describing crystal lattice properties on…

Computational Physics · Physics 2019-04-25 Simon Praetorius , Marco Salvalaglio , Axel Voigt

Maxwell's equations for propagation of electromagnetic waves in dispersive and absorptive (passive) media are represented in the form of the Schr\"odinger equation $i\partial \Psi/\partial t = {H}\Psi$, where ${H}$ is a linear differential…

Computational Physics · Physics 2009-11-11 Andrei G. Borisov , Sergei V. Shabanov

Cryo-electron microscopy (EM) single particle reconstruction is an entirely general technique for 3D structure determination of macromolecular complexes. However, because the images are taken at low electron dose, it is extremely hard to…

Computer Vision and Pattern Recognition · Computer Science 2019-04-17 Yifeng Fan , Zhizhen Zhao

Radio Frequency Interference (RFI) increasingly contaminates the radio astronomy spectrum, often exceeding astronomical signal amplitudes by 50-70 dB. Reliable detection and mitigation are therefore essential for studies of faint transient…

Instrumentation and Methods for Astrophysics · Physics 2026-05-08 Natalia A. Schmid , Sasanka Katreddi , Yechan Kweon

This paper studies a two-phase material with a microstructure composed of a hard brittle reinforcement phase embedded in a soft ductile matrix. It addresses the full three-dimensional nature of the microstructure and macroscopic…

Materials Science · Physics 2016-04-14 T. W. J. de Geus , M. Cottura , B. Appolaire , R. H. J. Peerlings , M. G. D. Geers

In this manuscript, we extend the variational multiscale enrichment (VME) method to model the dynamic response of hyperelastic materials undergoing large deformations. This approach enables the simulation of wave propagation under…

Computational Engineering, Finance, and Science · Computer Science 2025-11-19 Abhishek Arora , Caglar Oskay

The usual fluid equations describing the large-scale evolution of mass density in the universe can be written as local in the density, velocity divergence, and velocity potential fields. As a result, the perturbative expansion in small…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-01 Marcel Schmittfull , Zvonimir Vlah , Patrick McDonald

We consider photonic crystal fibres (PCFs) made from arbitrary base materials and introduce a short-wavelength approximation which allows for a mapping of the Maxwell's equations onto a dimensionless eigenvalue equations which has the form…

Optics · Physics 2007-05-23 Niels Asger Mortensen

In this paper, a novel and robust algorithm is proposed for adaptive beamforming based on the idea of reconstructing the autocorrelation sequence (ACS) of a random process from a set of measured data. This is obtained from the first column…

Information Theory · Computer Science 2021-06-25 Saeed Mohammadzadeh , Vitor H. Nascimento , Rodrigo C. de Lamare , Osman Kukrer

This paper is concerned with three-dimensional acoustic wave scattering in two-layer media, where the two homogeneous layers are separated by a locally perturbed plane featuring an axially symmetric perturbation. A fast novel boundary…

Numerical Analysis · Mathematics 2024-12-17 Hangya Wang , Wangtao Lu

We develop a formalism for the calculation of the frequency band structure of a phononic crystal consisting of non-overlapping elastic spheres, characterized by Lam\'e coefficients which may be complex and frequency dependent, arranged…

Materials Science · Physics 2009-10-31 I. E. Psarobas , N. Stefanou , A. Modinos

The goal of this paper is to generate realistic audio with a lightweight and fast diffusion-based vocoder, named FreGrad. Our framework consists of the following three key components: (1) We employ discrete wavelet transform that decomposes…

Audio and Speech Processing · Electrical Eng. & Systems 2024-01-19 Tan Dat Nguyen , Ji-Hoon Kim , Youngjoon Jang , Jaehun Kim , Joon Son Chung

The synchrosqueezing transform, a kind of reassignment method, aims to sharpen the time-frequency representation and to separate the components of a multicomponent non-stationary signal. In this paper, we consider the short-time Fourier…

Signal Processing · Electrical Eng. & Systems 2019-09-27 Lin Li , Haiyan Cai , Hongxia Han , Qingtang Jiang , Hongbing Ji

The standing waves existed in radio telescope data are primarily due to reflections among the instruments, which significantly impact the spectrum quality of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Eliminating…

Instrumentation and Methods for Astrophysics · Physics 2025-01-09 Chen Xu , Jie Wang , Yingjie Jing , Fujia Li , Hengqian Gan , Ziming Liu , Tiantian Liang , Qingze Chen , Zerui Liu , Zhipeng Hou , Hao Hu , Huijie Hu , Shijie Huang , Peng Jiang , Chuan-Peng Zhang , Yan Zhu

We investigate second order linear wave equations in periodic media, aiming at the derivation of effective equations in $\R^n$, $n \in \{1, 2, 3\}$. Standard homogenization theory provides, for the limit of a small periodicity length…

Analysis of PDEs · Mathematics 2013-09-02 Tomas Dohnal , Agnes Lamacz , Ben Schweizer

We have developed FFT beamforming techniques for the CHIME radio telescope, to search for and localize the astrophysical signals from Fast Radio Bursts (FRBs) over a large instantaneous field-of-view (FOV) while maintaining the full angular…

Instrumentation and Methods for Astrophysics · Physics 2021-03-22 C. Ng , K. Vanderlinde , A. Paradise , P. Klages , K. Masui , K. Smith , K. Bandura , P. J. Boyle , M. Dobbs , V. Kaspi , A. Renard , J. R. Shaw , I. Stairs , I. Tretyakov

The linear properties of the low-frequency shear Alfv\'en waves such as those associated with the beta-induced Alfv\'en eigenmodes (BAEs) and the low-frequency modes observed in reversed-magnetic-shear DIII-D discharges (W. Heidbrink, et al…

Plasma Physics · Physics 2023-04-19 Ruirui Ma , W. W. Heidbrink , Liu Chen , Fulvio Zonca , Zhiyong Qiu

The elastodynamic response of finite 3D phononic structures is analyzed by means of comparing experimental findings obtained through a laser Doppler vibrometry-based methodology and theoretical computations performed with the…

Materials Science · Physics 2019-04-24 I. K. Tragazikis , D. A. Exarchos , P. T. Dalla , K. Dassios , T. E. Matikas , I. E. Psarobas