English
Related papers

Related papers: Dynamic Implicit 3D Adaptive Mesh Refinement for N…

200 papers

Dynamic Magnetic Resonance Imaging (MRI) is a crucial non-invasive method used to capture the movement of internal organs and tissues, making it a key tool for medical diagnosis. However, dynamic MRI faces a major challenge: long…

Image and Video Processing · Electrical Eng. & Systems 2024-09-20 Tamir Shor , Chaim Baskin , Alex Bronstein

Different relaxation approximations to partial differential equations, including conservation laws, Hamilton-Jacobi equations, convection-diffusion problems, gas dynamics problems, have been recently proposed. The present paper focuses onto…

Numerical Analysis · Mathematics 2008-04-04 F. Cavalli , M. Semplice

In this paper, we develop two fast implicit difference schemes for solving a class of variable-coefficient time-space fractional diffusion equations with integral fractional Laplacian (IFL). The proposed schemes utilize the graded $L1$…

Numerical Analysis · Mathematics 2021-07-26 Xian-Ming Gu , Hai-Wei Sun , Yanzhi Zhang , Yong-Liang Zhao

The computation of the radiative transfer equation is expensive mainly due to two stiff terms: the transport term and the collision operator. The stiffness in the former comes from the fact that particles (such as photons) travels at the…

Numerical Analysis · Mathematics 2017-05-24 Qin Li , Li Wang

A new field of numerical astrophysics is introduced which addresses the solution of large, multidimensional structural or slowly-evolving problems (rotating stars, interacting binaries, thick advective accretion disks, four dimensional…

Astrophysics · Physics 2009-10-30 David L. Meier

Optimal input design is an important step of the identification process in order to reduce the model variance. In this work a D-optimal input design method for finite-impulse-response-type nonlinear systems is presented. The optimization of…

Systems and Control · Computer Science 2017-03-27 Alexander De Cock , Michel Gevers , Johan Schoukens

In this article, we propose novel boundary treatment algorithms to avoid order reduction when implicit-explicit Runge-Kutta time discretization is used for solving convection-diffusion-reaction problems with time-dependent Di\-richlet…

Numerical Analysis · Mathematics 2024-10-07 V. González-Tabernero , J. G. López-Salas , M. J. Castro-Díaz , J. A. García-Rodríguez

We propose a time-adaptive predictor/multi-corrector method to solve hyperbolic partial differential equations, based on the generalized-$\alpha$ scheme that provides user-control on the numerical dissipation and second-order accuracy in…

Numerical Analysis · Mathematics 2022-10-11 Nicolas A. Labanda , Pouria Behnoudfar , Victor M. Calo

Deep MRI reconstruction is commonly performed with conditional models that de-alias undersampled acquisitions to recover images consistent with fully-sampled data. Since conditional models are trained with knowledge of the imaging operator,…

Image and Video Processing · Electrical Eng. & Systems 2023-09-19 Alper Güngör , Salman UH Dar , Şaban Öztürk , Yilmaz Korkmaz , Gokberk Elmas , Muzaffer Özbey , Tolga Çukur

An efficient method for solving large nonlinear problems combines Newton solvers and Domain Decomposition Methods (DDM). In the DDM framework, the boundary conditions can be chosen to be primal, dual or mixed. The mixed approach presents…

Numerical Analysis · Mathematics 2018-02-07 Camille Negrello , Pierre Gosselet , Christian Rey

Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-25 Audrey Repetti , Jasleen Birdi , Arwa Dabbech , Yves Wiaux

We develop a new semi-analytical method for solving multilayer diffusion problems with time-varying external boundary conditions and general internal boundary conditions at the interfaces between adjacent layers. The convergence rate of the…

Numerical Analysis · Mathematics 2018-04-26 Elliot J. Carr , Nathan G. March

With the rapid growth of neuroimaging technologies, a great effort has been dedicated recently to investigate the dynamic changes in brain activity. Examples include time course calcium imaging and dynamic brain functional connectivity. In…

Methodology · Statistics 2020-08-31 Wei Hu , Tianyu Pan , Dehan Kong , Weining Shen

One difficulty in developing numerical methods for hyperbolic systems of conservation laws is the fact that solutions often contain regions where much higher resolution is required than elsewhere in the domain, particularly since the…

Numerical Analysis · Mathematics 2015-11-12 Brisa N. Davis , Randall J. LeVeque

We propose a general algorithm for non-conforming adaptive mesh refinement (AMR) of unstructured meshes in high-order finite element codes. Our focus is on h-refinement with a fixed polynomial order. The algorithm handles triangular,…

Numerical Analysis · Computer Science 2019-05-13 Jakub Červený , Veselin Dobrev , Tzanio Kolev

A nonlinear diffusion equation is proposed to account for thermalization in fermionic and bosonic systems through analytical solutions. For constant transport coefficients, exact time-dependent solutions are derived through nonlinear…

High Energy Physics - Phenomenology · Physics 2022-11-28 Georg Wolschin

This paper is concerned with moving mesh finite difference solution of partial differential equations. It is known that mesh movement introduces an extra convection term and its numerical treatment has a significant impact on the stability…

Numerical Analysis · Mathematics 2015-07-31 Weizhang Huang

We have developed a simulation code with the techniques which enhance both spatial and time resolution of the PM method for which the spatial resolution is restricted by the spacing of structured mesh. The adaptive mesh refinement (AMR)…

Astrophysics · Physics 2009-11-06 Hideki Yahagi , Yuzuru Yoshii

The radiation diffusion problem is a kind of {time-dependent} nonlinear equations. For solving the radiation diffusion equations, many linear systems are obtained in the nonlinear iterations at each time step. The cost of linear equations…

Numerical Analysis · Mathematics 2020-02-19 Shuai Ye , Hengbin An , Xinhai Xu

In this paper, we present a model based on a local thermodynamic equilibrium, weakly ionized plasma-mixture model used for medical and technical applications in etching processes. We consider a simplified model based on the Maxwell-Stefan…

Numerical Analysis · Mathematics 2015-01-26 Juergen Geiser