English
Related papers

Related papers: Reconstruction for multiwave imaging in attenuatin…

200 papers

This short note modifies a reconstruction method by the author (Comm. PDE, 45(9):1118-1133, 2020), for reconstructing piecewise constant conductivities in the Calder\'on problem (electrical impedance tomography). In the former paper, a…

Analysis of PDEs · Mathematics 2025-12-08 Henrik Garde

Due to the energy-dependent nature of the attenuation coefficient and the polychromaticity of the X-ray source, beam hardening effect occurs when X-ray photons penetrate through an object, causing a nonlinear projection data. When a linear…

Medical Physics · Physics 2018-12-07 Wei Zhao , Dengwang Li , Kai Niu , Wenjian Qin , Hao Peng , Tianye Niu

In computed tomography, data consist of measurements of the attenuation of X-rays passing through an object. The goal is to reconstruct the linear attenuation coefficient of the object's interior. For each position of the X-ray source,…

We consider the reconstruction of optical parameters in a domain of interest from photoacoustic data. Photoacoustic tomography (PAT) radiates high frequency electromagnetic waves into the domain and measures acoustic signals emitted by the…

Mathematical Physics · Physics 2015-05-14 Guillaume Bal , Alexandre Jollivet , Vincent Jugnon

In this paper, we propose a new spectral decomposition method to simulate waves propagating in complicated waveguides. For the numerical solutions of waveguide scattering problems, an important task is to approximate the…

Numerical Analysis · Mathematics 2022-07-27 Ruming Zhang

Decay rates for the energy of solutions of the damped wave equation on the torus are studied. In particular, damping invariant in one direction and equal to a sum of squares of nonnegative functions with a particular number of derivatives…

Analysis of PDEs · Mathematics 2021-06-18 Perry Kleinhenz

Although many long-range imaging systems are designed to support extended vision applications, a natural obstacle to their operation is degradation due to atmospheric turbulence. Atmospheric turbulence causes significant degradation to…

Computer Vision and Pattern Recognition · Computer Science 2022-09-21 Nithin Gopalakrishnan Nair , Kangfu Mei , Vishal M. Patel

We study iterative signal reconstruction in computed tomography (CT), wherein measurements are produced by a linear transformation of the unknown signal followed by an exponential nonlinear map. Approaches based on pre-processing the data…

Optimization and Control · Mathematics 2024-07-19 Vasileios Charisopoulos , Rebecca Willett

Many stochastic time series can be described by a Langevin equation composed of a deterministic and a stochastic dynamical part. Such a stochastic process can be reconstructed by means of a recently introduced nonparametric method, thus…

Data Analysis, Statistics and Probability · Physics 2013-01-01 J. Carvalho , F. Raischel , M. Haase , P. G. Lind

Photoacoustic tomography seeks to reconstruct an acoustic initial pressure distribution from the measurement of the ultrasound waveforms. Conventional methods assume a-prior knowledge of the sound speed distribution, which practically is…

Image and Video Processing · Electrical Eng. & Systems 2019-09-16 Hongming Shan , Christopher Wiedeman , Ge Wang , Yang Yang

We propose a new approach to the problem of recovering signal from frame coefficients with erasures. Such problems arise naturally from applications where some of the coefficients could be corrupted or erased during the data transmission.…

Functional Analysis · Mathematics 2016-02-05 Ljiljana Arambasic , Damir Bakic

In this work the Lippmann-Schwinger equation is used to model seismic waves in strongly scattering acoustic media. We consider the Helmholtz equation, which is the scalar wave equation in the frequency domain with constant density and…

Computational Physics · Physics 2021-02-24 Kjersti Solberg Eikrem , Geir Nævdal , Morten Jakobsen

We add a time-dependent potential to the inhomogeneous wave equation and consider the task of reconstructing this potential from measurements of the wave field. This dynamic inverse problem becomes more involved compared to static…

Numerical Analysis · Mathematics 2017-08-24 Thies Gerken , Armin Lechleiter

A new mechanisms for damping of slow magnetosonic waves (SMW) by pressure induced oscillations of the ionization degree is proposed. An explicit formula for the damping rate is quantitatively derived. Physical conditions where the new…

Plasma Physics · Physics 2020-12-02 Todor M. Mishonov , Albert M. Varonov

A rigorous reduction of the many-body wave scattering problem to solving a linear algebraic system is given bypassing solving the usual system of integral equation. The limiting case of infinitely many small particles embedded into a medium…

Mathematical Physics · Physics 2009-11-13 A. G. Ramm

Quantitative Photoacoustic tomography (QPAT) is an emerging medical imaging modality which offers the possibility of combining the high resolution of the acoustic waves and large contrast of optical waves by quantifying the molecular…

Numerical Analysis · Mathematics 2014-10-30 Adriano De Cezaro , Fabiana Travessini De Cezaro

In this paper, we study the photoacoustic tomography problem for which we seek to recover both the initial state of the pressure field and the wave speed of the medium from the knowledge of a single boundary measurement. The goal is to…

Analysis of PDEs · Mathematics 2020-07-01 Sebastian Acosta

The mathematical foundation of X-ray CT is based on the assumption that by measuring the attenuation of X-rays passing through an object, one can recover the integrals of the attenuation coefficient $\mu(x)$ along a sufficiently rich family…

Numerical Analysis · Mathematics 2025-05-07 Alexander Katsevich

Three-dimensional x-ray CT image reconstruction in baggage scanning in security applications is an important research field. The variety of materials to be reconstructed is broader than medical x-ray imaging. Presence of high attenuating…

Computer Vision and Pattern Recognition · Computer Science 2015-08-20 S. Degirmenci , Joseph A. O'Sullivan , David G. Politte

We study the problem of recovering the initial data (f, 0) of the standard wave equation from the Neumann trace (the normal derivative) of the solution on the boundary of convex domains in arbitrary spatial dimension. Among others, this…

Analysis of PDEs · Mathematics 2021-01-26 Florian Dreier , Markus Haltmeier