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We study the seismic inverse problem for the recovery of subsurface properties in acoustic media. In order to reduce the ill-posedness of the problem, the heterogeneous wave speed parameter to be recovered is represented using a limited…

Analysis of PDEs · Mathematics 2020-09-10 Florian Faucher , Otmar Scherzer , Hélène Barucq

In this paper, we study the low-complexity channel reconstruction methods for downlink precoding in massive multiple-Input multiple-Output (MIMO) systems. When the user is allocated less streams than the number of its antennas, the base…

Information Theory · Computer Science 2015-10-30 Yuwei Ren , Yang Song , Xin Su

The paper presents algorithms to realize effectively and accurately the stepped-frequency waveform reflectometry (SFWR), i.e. the reflectometric technique based on the use of sinusoidal bursts. This technique is useful for monitoring the…

Signal Processing · Electrical Eng. & Systems 2020-02-19 Nicola Giaquinto , Marco Scarpetta , Maurizio Spadavecchia

In this paper, we present algorithms for reconstructing an unknown compact scatterer embedded in a random noisy background medium, given measurements of the scattered field and information about the background medium and the sound profile.…

Numerical Analysis · Mathematics 2019-01-29 Carlos Borges , George Biros

We apply the four dimensional variational method to reconstruct the small scales of three-dimensional turbulent velocity fields with a moderate Reynolds number, given a time sequence of measurement data on a coarse set of grid points. The…

Fluid Dynamics · Physics 2020-02-19 Yi Li , Jianlei Zhang , Gang Dong , Naseer S. Abdullah

This paper is dedicated to design a direct sampling method of inverse electromagnetic scattering problems, which uses multi-frequency sparse backscattering far field data for reconstructing the boundary of perfectly conducting obstacles. We…

Analysis of PDEs · Mathematics 2020-10-28 Tilo Arens , Xia Ji , Xiaodong Liu

Near the band edge of photonic crystal waveguides, localized modes appear due to disorder. We demonstrate a new method to elucidate spatial profile of the localized modes in such systems using precise local tuning. Using deconvolution with…

Optics · Physics 2016-11-03 J. Lian , S. Sokolov , E. Yüce , S. Combrié , A. De Rossi , A. P. Mosk , .

Fabrication imperfections must be considered during configuration to ensure that the setup is suitable for the actual fabricated programmable photonic integrated circuits (PPICs). Therefore, characterization of imperfections is crucial but…

Optics · Physics 2024-06-11 Ran Tao , Jifang Qiu , Yuchen Chen , Bowen Zhang , Yan Li , Hongxiang Guo , Jian Wu

Spatial resolution of most imaging devices is fundamentally restricted by diffraction. This limitation is manifested in the loss of high spatial frequency information contained in evanescent waves. As a result, conventional far-field optics…

Optics · Physics 2010-03-16 Leonid Alekseyev , Evgenii Narimanov , Jacob Khurgin

This paper deals with the reconstruction of the direction of a gravitational wave source using the detection made by a network of interferometric detectors, mainly the LIGO and Virgo detectors. We suppose that an event has been seen in…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Cavalier , M. Barsuglia , M. -A. Bizouard , V. Brisson , A. -C. Clapson , M. Davier , P. Hello , S. Kreckelbergh , N. Leroy , M. Varvella

We apply adaptive sensing techniques to the problem of locating sparse metallic scatterers using high-resolution, frequency modulated continuous wave W-band RADAR. Using a single detector, a frequency stepped source, and a lateral…

Imaging techniques give a fundamental support to medical diagnostics during the pathology discovery as well as for the characterization of biological structures. The imaging methods involve electromagnetic waves in a frequency range that…

Computational Physics · Physics 2016-11-26 Guido Ala , Pietro Cassara' , Elisa Francomano , Salvatore Ganci

We consider the reconstruction of the shape and the impedance function of an obstacle from measurements of the scattered field at receivers outside the object. The data is assumed to be generated by plane waves impinging on the obstacle…

Numerical Analysis · Mathematics 2021-04-29 Carlos Borges , Manas Rachh

We study the vibrational spectra of one-dimensional statically compressed granular crystals (arrays of elastic particles in contact) containing defects. We focus on the prototypical settings of one or two spherical defects (particles of…

Other Condensed Matter · Physics 2011-03-15 N. Boechler , G. Theocharis , Y. Man , P. G. Kevrekidis , C. Daraio

In order to measure the radial displacements of facets on surface of a growing spherical Cu_{2-\delta}Se crystal with sub-nanometer resolution, we have investigated the reliability and accuracy of standard method of Fourier analysis of…

Optics · Physics 2009-11-13 Jadranko Gladic , Zlatko Vucic , Davorin Lovric

An elastic ideal 2D propagation medium, i.e., a membrane, can be simulated by models discretizing the wave equation on the time-space grid (finite difference methods), or locally discretizing the solution of the wave equation (waveguide…

Sound · Computer Science 2024-09-21 Federico Fontana , Davide Rocchesso

Localizing linearly moving sound sources using microphone arrays is challenging as the transient nature of the signal leads to relatively short observation periods. Commonly, a moving focus is used and most methods operate at least…

Audio and Speech Processing · Electrical Eng. & Systems 2024-08-21 Christian H. Kasess , Wolfgang Kreuzer , Prateek Soni , Holger Waubke

Photonic crystal waveguides (PCWs) allow for the engineering of photonic modes and band structures to control the flow of light and light-matter interactions within the waveguide. They have shown potential for enhancing optical…

Optics · Physics 2026-02-13 Dominic Thompson , Antonia Neill , Nir Rotenberg , Stephen Hughes

With the emergence of wireless applications in three-dimensional environments, such as the low-altitude airspace and 3D heterogeneous networks, radio map estimation is increasingly required to characterize signal propagation across both…

Computer Vision and Pattern Recognition · Computer Science 2026-05-29 Zheng Fang , Junjie Liu , Kangjun Liu , Jianguo Zhang , Yaowei Wang , Ke Chen

Data dimensionality reduction in radio interferometry can provide savings of computational resources for image reconstruction through reduced memory footprints and lighter computations per iteration, which is important for the scalability…

Instrumentation and Methods for Astrophysics · Physics 2017-05-03 S. Vijay Kartik , Rafael E. Carrillo , Jean-Philippe Thiran , Yves Wiaux