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Highly heterogeneous, anisotropic coefficients, e.g. in the simulation of carbon-fibre composite components, can lead to extremely challenging finite element systems. Direct solvers for the resulting large and sparse linear systems suffer…

Numerical Analysis · Mathematics 2021-06-16 Peter Bastian , Robert Scheichl , Linus Seelinger , Arne Strehlow

In this paper a new high order semi-implicit discontinuous Galerkin method (SI-DG) is presented for the solution of the incompressible Navier-Stokes equations on staggered space-time adaptive Cartesian grids (AMR) in two and three…

Numerical Analysis · Mathematics 2017-08-02 Francesco Fambri , Michael Dumbser

This paper presents a computational scheme for the determination of equivalent 2D multi-group heterogeneous reflectors in a Pressurized Water Reactor (PWR). The proposed strategy is to define a full-core calculation consistent with a…

We present a robust and accurate numerical method for the anisotropic diffusion equation in curvilinear coordinates. This study extends the recent work [Muir et al., Computer Physics Communications, 2025] for solving the anisotropic…

Numerical Analysis · Mathematics 2026-04-23 Dean Muir , Kenneth Duru , Stuart Hudson , Matthew Hole

Large linear systems with sparse, non-symmetric matrices arise in the modeling of Markov chains or in the discretization of convection-diffusion problems. Due to their potential to solve sparse linear systems with an effort that is linear…

Numerical Analysis · Mathematics 2023-08-17 Benjamin Seibold

Mixed-frame formulations of radiation-hydrodynamics (RHD), where the radiation quantities are computed in an inertial frame but matter quantities are in a comoving frame, are advantageous because they admit algorithms that conserve energy…

Astrophysics of Galaxies · Physics 2024-11-25 Chong-Chong He , Benjamin D. Wibking , Mark R. Krumholz

We propose an easy-to-implement iterative method for resolving the implicit (or semi-implicit) schemes arising in solving reaction-diffusion (RD) type equations. We formulate the nonlinear time implicit scheme as a min-max saddle point…

Numerical Analysis · Mathematics 2023-05-09 Shu Liu , Siting Liu , Stanley Osher , Wuchen Li

In this paper, we develop a class of high-order conservative methods for simulating non-equilibrium radiation diffusion problems. Numerically, this system poses significant challenges due to strong nonlinearity within the stiff source terms…

Numerical Analysis · Mathematics 2024-01-30 Shaoqin Zheng , Min Tang , Qiang Zhang , Tao Xiong

We describe a photon-conserving radiative transfer algorithm, using a spatially-adaptive ray tracing scheme, and its parallel implementation into the adaptive mesh refinement (AMR) cosmological hydrodynamics code, Enzo. By coupling the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 John H. Wise , Tom Abel

This paper focuses on developing a reduction-based algebraic multigrid method that is suitable for solving general (non)symmetric linear systems and is naturally robust from pure advection to pure diffusion. Initial motivation comes from a…

Numerical Analysis · Mathematics 2024-05-16 Ahsan Ali , James Brannick , Karsten Kahl , Oliver A. Krzysik , Jacob B. Schroder , Ben S. Southworth

We present a novel method for diffusion-guided frameworks for view-consistent super-resolution (SR) in neural rendering. Our approach leverages existing 2D SR models in conjunction with advanced techniques such as Variational Score…

Computer Vision and Pattern Recognition · Computer Science 2025-01-07 Shrey Vishen , Jatin Sarabu , Saurav Kumar , Chinmay Bharathulwar , Rithwick Lakshmanan , Vishnu Srinivas

Diffusion models have gained significant popularity in the field of image-to-image translation. Previous efforts applying diffusion models to image super-resolution (SR) have demonstrated that iteratively refining pure Gaussian noise using…

Computer Vision and Pattern Recognition · Computer Science 2023-07-04 Axi Niu , Pham Xuan Trung , Kang Zhang , Jinqiu Sun , Yu Zhu , In So Kweon , Yanning Zhang

This article shows how to develop an efficient solver for a stabilized numerical space-time formulation of the advection-dominated diffusion transient equation. At the discrete space-time level, we approximate the solution by using…

Numerical Analysis · Mathematics 2023-06-30 Marcin Łoś , Paulina Sepulveda-Salas , Maciej Paszyński

In this paper we present a fourth-order in space and time block-structured adaptive mesh refinement algorithm for the compressible multicomponent reacting Navier-Stokes equations. The algorithm uses a finite volume approach that…

Fluid Dynamics · Physics 2019-02-15 Matthew Emmett , Emmanuel Motheau , Weiqun Zhang , Michael Minion , John B. Bell

We present a method for optimizing the location of the fermion ground-state nodes using a combination of diffusion Monte Carlo (DMC) and projected gradient descent (PGD). A PGD iteration shifts the parameters of an arbitrary node-fixing…

Computational Physics · Physics 2022-04-06 John McFarland , Efstratios Manousakis

In this paper we first review the development of high order ADER finite volume and ADER discontinuous Galerkin schemes on fixed and moving meshes, since their introduction in 1999 by Toro et al. We show the modern variant of ADER based on a…

Computational Physics · Physics 2020-02-25 Saray Busto , Simone Chiocchetti , Michael Dumbser , Elena Gaburro , Ilya Peshkov

In this paper, we propose a unified and high order accurate fully-discrete one-step ADER Discontinuous Galerkin method for the simulation of linear seismic waves in the sea bottom that are generated by the propagation of free surface water…

Numerical Analysis · Mathematics 2020-04-08 Caterina Bassi , Saray Busto , Michael Dumbser

Adaptive mesh refinement (AMR) is a classical technique about local refinement in space where needed, thus effectively reducing computational costs for HPC-based physics simulations. Although AMR has been used for many years, little…

Fluid Dynamics · Physics 2024-05-14 Dewen Liu , Shuai He , Haoran Cheng , Yadong Zeng

We develop a new spatial semidiscrete multiscale method based upon the edge multiscale methods to solve semilinear parabolic problems with heterogeneous coefficients and smooth initial data. This method allows for a cheap spatial…

Numerical Analysis · Mathematics 2025-12-16 Leonardo A. Poveda , Shubin Fu , Guanglian Li , Eric Chung

In this work, a gray level indicator based non-linear telegraph diffusion model is presented for multiplicative noise removal problem. Most of the researchers focus only on diffusion equation-based model for multiplicative noise removal…

Numerical Analysis · Mathematics 2019-08-08 Sudeb Majee , Rajendra K Ray , Ananta K Majee