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Computational spectral imaging (CSI) achieves real-time hyperspectral imaging through co-designed optics and algorithms, but typical CSI methods suffer from a bulky footprint and limited fidelity. Therefore, Spectral Deconvolution imaging…

Image and Video Processing · Electrical Eng. & Systems 2025-11-11 Tao Lv , Daoming Zhou , Chenglong Huang , Chongde Zi , Linsen Chen , Xun Cao

An adaptive algorithm for spectral proper orthogonal decomposition (SPOD) of mixed broadband-tonal turbulent flows is developed. Sharp peak resolution at tonal frequencies is achieved by locally minimizing the bias of the spectrum. Smooth…

Fluid Dynamics · Physics 2024-06-25 Brandon C. Y. Yeung , Oliver T. Schmidt

This paper concerns the use of asymptotic expansions for the efficient solving of forward and inverse problems involving a nonlinear singularly perturbed time-dependent reaction--diffusion--advection equation. By using an asymptotic…

Numerical Analysis · Mathematics 2023-02-15 Dmitrii Chaikovskii , Ye Zhang

Unsupervised Anomalous Sound Detection (ASD) aims to design a generalizable method that can be used to detect anomalies when only normal sounds are given. In this paper, Anomalous Sound Detection based on Diffusion Models (ASD-Diffusion) is…

Sound · Computer Science 2024-09-25 Fengrun Zhang , Xiang Xie , Kai Guo

This work studies a posteriori error estimates and their use for time-dependent acoustic scattering problems, formulated as a time-dependent boundary integral equation based on a single-layer ansatz. The integral equation is discretized by…

Numerical Analysis · Mathematics 2025-09-05 Théophile Chaumont-Frelet , Heiko Gimperlein , Ignacio Labarca-Figueroa , Jörg Nick

The object of this work is to design an adequate regularization for the problem of recovering missing Fourier coefficients, particularly in some non standard situations were low frequency coefficients are lost. In the framework of non-local…

Numerical Analysis · Mathematics 2014-02-04 Antonin Chambolle , Khalid Jalalzai

Practical applications of microwave imaging often require the solution of inverse scattering problems with inhomogeneous backgrounds. Towards this end, a novel inversion strategy, which combines the multi-scaling (MS) regularization scheme…

Signal Processing · Electrical Eng. & Systems 2024-01-08 Yu Zhong , Francesco Zardi , Marco Salucci , Giacomo Oliveri , Andrea Massa

This paper considers the inverse problem of scattering of time-harmonic acoustic and electromagnetic plane waves by a bounded, inhomogeneous, penetrable obstacle with embedded objects inside. A new method is proposed to prove that the…

Analysis of PDEs · Mathematics 2017-06-14 Jiaqing Yang , Bo Zhang , Haiwen Zhang

Seismic acoustic impedance inversion is a challenging problem in geophysical exploration, primarily due to the scarcity of well-logging data and the inherent nonlinearity of the task. Most existing inversion methods, including…

Geophysics · Physics 2025-11-25 Junheng Peng , Yingtian Liu , Xiaowen Wang , Yong Li , Mingwei Wang

We consider the inverse source problem arising in thermo- and photo-acoustic tomography. It consists in reconstructing the initial pressure from the boundary measurements of the acoustic wave. Our goal is to extend versatile time reversal…

Analysis of PDEs · Mathematics 2015-11-13 Linh V. Nguyen , Leonid Kunyansky

The auxiliary space preconditioning (ASP) technique is applied to the HDG schemes for three different elliptic problems with a parameter dependent low order term, namely, a symmetric interior penalty HDG scheme for the scalar…

Numerical Analysis · Mathematics 2020-11-25 Guosheng Fu

We have developed a symmetry-adapted modeling procedure for molecules and crystals. By using the completeness of multipoles to express spatial and time-reversal parity-specific anisotropic distributions, we can generate systematically the…

Materials Science · Physics 2023-05-12 Hiroaki Kusunose , Rikuto Oiwa , Satoru Hayami

In this paper, we consider the initial boundary value problem of the two dimensional multi-term time fractional mixed diffusion and diffusion-wave equations. An alternating direction implicit (ADI) spectral method is developed based on…

Numerical Analysis · Mathematics 2018-09-03 Zeting Liu , Fawang Liu , Fanhai Zeng

An inexact accelerated stochastic Alternating Direction Method of Multipliers (AS-ADMM) scheme is developed for solving structured separable convex optimization problems with linear constraints. The objective function is the sum of a…

Optimization and Control · Mathematics 2020-10-27 Jianchao Bai , William W. Hager , Hongchao Zhang

The non-linearities of the dynamics of Earth artificial satellites are encapsulated by two formal integrals that are customarily computed by perturbation methods. Standard procedures begin with a Hamiltonian simplification that removes…

Dynamical Systems · Mathematics 2020-09-23 Martin Lara

Arbitrary high order numerical methods for time-harmonic acoustic scattering problems originally defined on unbounded domains are constructed. This is done by coupling recently developed high order local absorbing boundary conditions (ABCs)…

Numerical Analysis · Mathematics 2020-06-17 Vianey Villamizar , Dane Grundvig , Otilio Rojas , Sebastian Acosta

We shall derive and propose several efficient overlapping domain decomposition methods for solving some typical linear inverse problems, including the identiffication of the flux, the source strength and the initial temperature in second…

Numerical Analysis · Mathematics 2013-09-10 Jiang Daijun , Feng Hui , Zou Jun

Adaptive beamforming can lead to substantial improvement in resolution and contrast of ultrasound images over standard delay and sum beamforming. Here we introduce the adaptive time-channel (ATC) beamformer, a data-driven approach that…

Signal Processing · Electrical Eng. & Systems 2021-10-19 Avner Shultzman , Oded Drori , Yonina C. Eldar

We consider the time-harmonic acoustic wave scattering by a bounded {\it anisotropic inhomogeneity} embedded in an unbounded {\it anisotropic} homogeneous medium. The material parameters may have discontinuities across the interface between…

Analysis of PDEs · Mathematics 2018-12-26 Otar Chkadua , Sergey E. Mikhailov , David Natroshvili

We propose a new randomized optimization method for high-dimensional problems which can be seen as a generalization of coordinate descent to random subspaces. We show that an adaptive sampling strategy for the random subspace significantly…

Optimization and Control · Mathematics 2019-12-19 Jonathan Lacotte , Mert Pilanci , Marco Pavone