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In this paper, contrast-independent partially explicit time discretization for wave equations in heterogeneous high-contrast media via mass lumping is concerned. By employing a mass lumping scheme to diagonalize the mass matrix, the matrix…

Numerical Analysis · Mathematics 2025-02-25 Shu Fan Li , Wing Tat Leung

We introduce a new domain decomposition strategy for time harmonic Maxwell's equations that is valid in the case of automatically generated subdomain partitions with possible presence of cross-points. The convergence of the algorithm is…

Numerical Analysis · Mathematics 2022-09-20 Xavier Claeys , Francis Collino , Emile Parolin

We deal with the photoacoustic imaging modality using dielectric nanoparticles as contrast agents. Exciting the heterogeneous tissue, localized in a bounded domain $\Omega$, with an electromagnetic wave, at a given incident frequency,…

Analysis of PDEs · Mathematics 2020-03-09 Ahcene Ghandriche , Mourad Sini

Generalized impedance boundary conditions are effective, approximate boundary conditions that describe scattering of waves in situations where the wave interaction with the material involves multiple scales. In particular, this includes…

Numerical Analysis · Mathematics 2020-05-29 Lehel Banjai , Christian Lubich , Joerg Nick

Multi-channel audio alignment is a key requirement in bioacoustic monitoring, spatial audio systems, and acoustic localization. However, existing methods often struggle to address nonlinear clock drift and lack mechanisms for quantifying…

Sound · Computer Science 2025-09-23 Ragib Amin Nihal , Benjamin Yen , Takeshi Ashizawa , Kazuhiro Nakadai

An approximate solution of the Dyson equation related to a stochastic Helmholtz equation, which describes the acoustic dynamics of a three-dimensional isotropic random medium with elastic tensor fluctuating in space, is obtained in the…

Disordered Systems and Neural Networks · Physics 2018-10-23 Maria Grazia Izzo , Giancarlo Ruocco , Stefano Cazzato

Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues.…

Medical Physics · Physics 2016-03-22 Samuel Powell , Simon R. Arridge , Terence S. Leung

We propose a self-adaptive absorbing technique for quasilinear ultrasound waves in two- and three-dimensional computational domains. As a model for the nonlinear ultrasound propagation in thermoviscous fluids, we employ Westervelt's wave…

Numerical Analysis · Mathematics 2019-05-01 Markus Muhr , Vanja Nikolić , Barbara Wohlmuth

We present a novel approach aimed at high-performance uncertainty quantification for time-dependent problems governed by partial differential equations. In particular, we consider input uncertainties described by a Karhunen-Loeeve expansion…

Computational Engineering, Finance, and Science · Computer Science 2021-02-05 Seif Ben Bader , Pietro Benedusi , Alessio Quaglino , Patrick Zulian , Rolf Krause

In this paper, the mixed equilibrium problem with coupled inequality constraints in dynamic environments is solved by employing a multi-agent system, where each agent only has access to its own bifunction, its own constraint function, and…

Systems and Control · Electrical Eng. & Systems 2024-12-30 Hang Xu , Kaihong Lu , Yu-Long Wang , Qixin Zhu

We analyse the nematic Helmholtz-Korteweg equation, a variant of the classical Helmholtz equation that describes time-harmonic wave propagation in calamitic fluids in the presence of nematic order. A prominent example is given by nematic…

Numerical Analysis · Mathematics 2026-05-27 Patrick E. Farrell , Tim van Beeck , Umberto Zerbinati

We introduce a framework for audio source separation using embeddings on a hyperbolic manifold that compactly represent the hierarchical relationship between sound sources and time-frequency features. Inspired by recent successes modeling…

Audio and Speech Processing · Electrical Eng. & Systems 2022-12-12 Darius Petermann , Gordon Wichern , Aswin Subramanian , Jonathan Le Roux

Multiscale and multiphysics problems need novel numerical methods in order for them to be solved correctly and predictively. To that end, we develop a wavelet based technique to solve a coupled system of nonlinear partial differential…

Numerical Analysis · Mathematics 2023-03-22 Cale Harnish , Luke Dalessandro , Karel Matous , Daniel Livescu

After briefly revising the concepts of consonance/dissonance, a respective mathematic-computational model is described, based on Helmholtz's consonance theory and also considering the partials intensity. It is then applied to characterize…

Sound · Computer Science 2019-06-18 Luciano da Fontoura Costa

In this study, a method for readily and inexpensively generating real-time reconfigurable intense midair ultrasound field is proposed. Recent investigations and applications of midair convergent high-power ultrasound have been increasingly…

Applied Physics · Physics 2025-03-24 Keisuke Hasegawa

The scattering and transmission of harmonic acoustic waves at a penetrable material are commonly modelled by a set of Helmholtz equations. This system of partial differential equations can be rewritten into boundary integral equations…

Numerical Analysis · Mathematics 2022-04-19 Elwin van 't Wout , Seyyed R. Haqshenas , Pierre Gélat , Timo Betcke , Nader Saffari

Deep learning approaches for black-box modelling of audio effects have shown promise, however, the majority of existing work focuses on nonlinear effects with behaviour on relatively short time-scales, such as guitar amplifiers and…

Sound · Computer Science 2023-05-11 Marco Comunità , Christian J. Steinmetz , Huy Phan , Joshua D. Reiss

This paper concerns the preconditioning technique for discrete systems arising from time-harmonic Maxwell equations with absorptions, where the discrete systems are generated by N\'ed\'elec finite element methods of fixed order on meshes…

Numerical Analysis · Mathematics 2025-02-24 Ziyi Li , Qiya Hu

Microbubbles - used as contrast agents in ultrasound imaging - are important tools in biomedical research, having been used together with ultrasound to develop significant diagnostic and therapeutic techniques. It has been suggested that…

Medical Physics · Physics 2022-11-23 Prashant Pandey

This paper investigates the following question: given a Galerkin matrix corresponding to a finite-element discretisation of either the Helmholtz or time-harmonic Maxwell equations with variable coefficients, suppose that the coefficients of…

Numerical Analysis · Mathematics 2026-01-15 Euan A. Spence