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In this paper, we introduce a novel numerical method for reconstructing the trajectory within three-dimensional space, where both the emission moment and spatial location of the point source are unknown. Our approach relies solely on…

Numerical Analysis · Mathematics 2025-07-29 Guanqiu Ma , Haonan Zhang , Hongxia Guo

Uncertainties of refractive and group index in dispersion measurement by spectrally resolved white light interferometry are deeply analyzed. First, the contribution to uncertainty of the different parameters affecting both indices is…

We study an inverse source problem for the acoustic wave equation in a random waveguide. The goal is to estimate the source of waves from measurements of the acoustic pressure at a remote array of sensors. The waveguide effect is due to…

Analysis of PDEs · Mathematics 2015-02-25 Sebastian Acosta , Ricardo Alonso , Liliana Borcea

The aim of this paper is to propose for the first time a reconstruction scheme and a stability result for recovering from acoustic-optic data absorption distributions with bounded variation. The paper extends earlier results on smooth…

Analysis of PDEs · Mathematics 2014-05-13 Habib Ammari , Loc Hoang Nguyen , Laurent Seppecher

With an increased interest in applications that require a clean background image, such as video surveillance, object tracking, street view imaging and location-based services on web-based maps, multiple algorithms have been developed to…

Computer Vision and Pattern Recognition · Computer Science 2018-04-13 Aditee Shrotre , Lina Karam

The currently used linear and nonlinear lens inversion techniques are based on distortion estimators whose complicated source redshift dependence makes the influence of the redshift distribution of the sources difficult to take into account…

Astrophysics · Physics 2007-05-23 Pierre-Yves Longaretti

We develop a discrete model to account for the effects of inhomogeneities on the redshift of photons. Using this model we compute the probability distribution of the observed redshift respect to the background value, obtaining that its…

General Relativity and Quantum Cosmology · Physics 2017-10-31 Antonio Enea Romano

Multipath effects significantly influence the quality of microwave imaging in highly reflective environments, while the physical measurement aperture size constrains resolution. It is shown that by exploiting multipath reflections, improved…

Image and Video Processing · Electrical Eng. & Systems 2026-05-06 Quanfeng Wang , Mei Song Tong , Thomas F. Eibert

The image restoration problem is one of the popular topics in image processing studied by many authors on account of its applications in various areas. The aim of this paper is to present a new algorithm by using viscosity approximation…

Functional Analysis · Mathematics 2021-08-12 Ebru ALTIPARMAK , Ibrahim KARAHAN

Matter-wave interferometry with solids is highly susceptible to minute fluctuations of environmental fields, including gravitational effects from distant sources. Hence, experiments require a degree of shielding that is extraordinarily…

Quantum Physics · Physics 2022-08-23 Julen S. Pedernales , Martin B. Plenio

This work is devoted to the stability/resolution analysis of several imaging functionals in complex environments. We consider both linear functionals in the wavefield as well as quadratic functionals based on wavefield correlations. Using…

Analysis of PDEs · Mathematics 2015-01-27 G. Bal , O. Pinaud , L. Ryzhik

This paper concerns the frequency domain problem of diffraction of a plane wave incident on an infinite right-angled wedge on which impedance (absorbing) boundary conditions are imposed. It is demonstrated that the exact…

Analysis of PDEs · Mathematics 2015-06-22 David P. Hewett , Aaron Morris

Diffusion models achieve state-of-the-art performance in various generation tasks. However, their theoretical foundations fall far behind. This paper studies score approximation, estimation, and distribution recovery of diffusion models,…

Machine Learning · Computer Science 2023-02-15 Minshuo Chen , Kaixuan Huang , Tuo Zhao , Mengdi Wang

Light propagation through a normal medium is determined not only by the real part of the refractive index but also by its imaginary part, which represents optical gain and loss. Therefore, two media with different gain and loss landscapes…

Optics · Physics 2019-08-21 Jose Hernandez Rivero , Li Ge

Meteorological data have been used to calculate refractive index fluctuations - the indicator of optical instability of the Earth's atmosphere. The calculations were made for standard pressure levels of the atmosphere in winter and summer.…

Instrumentation and Methods for Astrophysics · Physics 2011-01-21 Pavel G. Kovadlo , Olga S. Kochetkova

Coherent diffractive imaging is a technique that recovers the sample image by numerically inverting its diffraction pattern. We propose a generalization of this method for the inversion of multi-wavelength data. Using this approach, we show…

Optics · Physics 2020-05-08 Erik Malm , Edwin Fohtung , Anders Mikkelsen

Direct imaging methods recover the presence, position, and shape of the unknown obstacles in time-harmonic inverse scattering without a priori knowledge of either the physical properties or the number of disconnected components of the…

Analysis of PDEs · Mathematics 2023-11-29 General Ozochiawaeze

We consider an inverse acoustic scattering problem in simultaneously recovering an embedded obstacle and its surrounding inhomogeneous medium by formally determined far-field data. It is shown that the knowledge of the scattering amplitude…

Analysis of PDEs · Mathematics 2017-05-24 Hongyu Liu , Xiaodong Liu

In this study, a novel illuminant color estimation framework is proposed for computational color constancy, which incorporates the high representational capacity of deep-learning-based models and the great interpretability of…

Computer Vision and Pattern Recognition · Computer Science 2020-05-07 Jueqin Qiu , Haisong Xu , Zhengnan Ye

Motivated by non-destructive testing of optical fiber, we consider the problem of determining the index of refraction of a two-dimensional medium from magnitude of the total field resulting from known incident plane waves at a fixed…

Analysis of PDEs · Mathematics 2016-08-01 Yat Tin Chow , Fadil Santosa , Gunther Uhlmann