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Related papers: Wavelets and sparsity for Faraday tomography

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Diffusion models have emerged as potential tools to tackle the challenge of sparse-view CT reconstruction, displaying superior performance compared to conventional methods. Nevertheless, these prevailing diffusion models predominantly focus…

Image and Video Processing · Electrical Eng. & Systems 2023-09-06 Kai Xu , Shiyu Lu , Bin Huang , Weiwen Wu , Qiegen Liu

Affine frequency division multiplexing (AFDM) has recently emerged as a promising waveform for doubly-selective channles [1],[2], owing to its ability to fully exploit time-frequency diversity through appropriate tuning of the chirp-rate…

Signal Processing · Electrical Eng. & Systems 2026-05-19 Haojian Zhang , Jiayan Yang , Tingting Zhang , Xu Zhu , Qinyu Zhang

We consider the Fast Fourier Transform (FFT) based numerical method for thin film magnetization problems [Vestg{\aa}rden and Johansen, SuST, 25 (2012) 104001], compare it with the finite element methods, and evaluate its accuracy. Proposed…

Computational Physics · Physics 2018-05-09 Leonid Prigozhin , Vladimir Sokolovsky

This paper investigates the shape reconstructions of sub-wavelength objects from near-field measurements in transverse electromagnetic scattering. This geometric inverse problem is notoriously ill-posed and challenging. We develop a novel…

Mathematical Physics · Physics 2023-05-03 M. H. Ding , H. Y. Liu , G. H. Zheng

Modern-day seismic imaging and monitoring technology increasingly rely on dense full-azimuth sampling. Unfortunately, the costs of acquiring densely sampled data rapidly become prohibitive and we need to look for ways to sparsely collect…

Optimization and Control · Mathematics 2020-04-22 Yijun Zhang , Shashin Sharan , Oscar Lopez , Felix J. Herrmann

Modeling the mass distribution of galaxy-scale strong gravitational lenses is a task of increasing difficulty. The high-resolution and depth of imaging data now available render simple analytical forms ineffective at capturing lens…

Instrumentation and Methods for Astrophysics · Physics 2022-12-21 Aymeric Galan , Georgios Vernardos , Austin Peel , Frédéric Courbin , Jean-Luc Starck

There is evidence that magnetized material along the line of sight to distant quasars is detectable in the polarization properties of the background sources. The polarization properties appear to be correlated with the presence of…

Astrophysics of Galaxies · Physics 2016-10-05 Kwang Seong Kim , Simon J. Lilly , Francesco Miniati , M. L. Bernet , Rainer Beck , S. P. O'Sullivan , B. M. Gaensler

Latest diffusion-based methods for many image restoration tasks outperform traditional models, but they encounter the long-time inference problem. To tackle it, this paper proposes a Wavelet-Based Diffusion Model (WaveDM). WaveDM learns the…

Computer Vision and Pattern Recognition · Computer Science 2024-01-26 Yi Huang , Jiancheng Huang , Jianzhuang Liu , Mingfu Yan , Yu Dong , Jiaxi Lv , Chaoqi Chen , Shifeng Chen

Envisioned as the next-generation transceiver technology, the holographic multiple-input-multiple-output (HMIMO) garners attention for its superior capabilities of fabricating electromagnetic (EM) waves. However, the densely packed antenna…

Information Theory · Computer Science 2024-06-05 Yuqing Guo , Xufeng Guo , Yuanbin Chen , Ying Wang

This paper investigates the inverse biharmonic scattering problems of identifying the shape and location of the obstacle with phased and phaseless measurement data. A direct imaging method based on reverse time migration is proposed for…

Analysis of PDEs · Mathematics 2026-05-12 Tielei Zhu , Zhihao Ge

A fast full-wave simulation technique is presented for the analysis of large irregular planar arrays of identical 3-D metallic antennas. The solution method relies on the Macro Basis Functions (MBF) approach and an interpolatory technique…

Instrumentation and Methods for Astrophysics · Physics 2018-05-09 Ha Bui-Van , Jens Abraham , Michel Arts , Quentin Gueuning , Christopher Raucy , David Gonzalez-Ovejero , Eloy de Lera Acedo , Christophe Craeye

Modeling the wireless radiance field (WRF) is fundamental to modern communication systems, enabling key tasks such as localization, sensing, and channel estimation. Traditional approaches, which rely on empirical formulas or physical…

Computer Vision and Pattern Recognition · Computer Science 2026-01-23 Mufan Liu , Cixiao Zhang , Qi Yang , Yujie Cao , Yiling Xu , Yin Xu , Shu Sun , Mingzeng Dai , Yunfeng Guan

Wireless OFDM channels can be approximated by a time varying filter with sparse time domain taps. Recent achievements in sparse signal processing such as compressed sensing have facilitated the use of sparsity in estimation, which improves…

Information Theory · Computer Science 2009-01-27 Mahdi Soltanolkotabi , Arash Amini , Farokh Marvasti

We introduce a unified approach that, given a strong gravitationally lensed polarised source, self-consistently infers its complex surface brightness distribution and the lens galaxy mass-density profile, magnetic field and electron density…

Astrophysics of Galaxies · Physics 2024-07-30 S. Ndiritu , S. Vegetti , D. M. Powell , J. P. McKean

We consider the inverse elastic scattering problems using the far field data due to one incident plane wave. A simple method is proposed to reconstruct the location and size of the obstacle using different components of the far field…

Analysis of PDEs · Mathematics 2019-04-09 J Liu , X. Liu , J. Sun

We develop mask iterative hard thresholding algorithms (mask IHT and mask DORE) for sparse image reconstruction of objects with known contour. The measurements follow a noisy underdetermined linear model common in the compressive sampling…

Machine Learning · Statistics 2011-12-05 Aleksandar Dogandzic , Renliang Gu , Kun Qiu

Fourier extension is an approximation method that alleviates the periodicity requirements of Fourier series and avoids the Gibbs phenomenon when approximating functions. We describe a similar extension approach using regular wavelet bases…

Numerical Analysis · Mathematics 2020-04-08 Vincent Coppé , Daan Huybrechs

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Charlotte Z. Bond , Carlos M. Correia , Jean-François Sauvage , Benoit Neichel , Thierry Fusco

Microwave imaging is commonly based on the solution of linearized inverse scattering problems by matched filtering algorithms, i.e., by applying the adjoint of the forward scattering operator to the observation data. A more rigorous…

Image and Video Processing · Electrical Eng. & Systems 2024-12-23 Matthias M. Saurer , Han Na , Marius Brinkmann , Thomas F. Eibert

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