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Related papers: ATEQ: Adaptive Toroidal Equilibrium code

200 papers

We present for astrophysical use a multi-dimensional numerical code to solve the equations for ideal magnetohydrodynamics (MHD). It is based on an explicit finite difference method on an Eulerian grid, called the Total Variation Diminishing…

Astrophysics · Physics 2016-08-30 Dongsu Ryu , T. W. Jones , Adam Frank

Adaptive optimization algorithms -- such as Adagrad, Adam, and their variants -- have found widespread use in machine learning, signal processing and many other settings. Several methods in this family are not rotationally equivariant,…

Machine Learning · Computer Science 2026-02-17 Adela DePavia , Jose Cruzado , Jiayou Liang , Vasileios Charisopoulos , Rebecca Willett

Recently, automorphism ensemble decoding (AED) has drawn research interest as a more computationally efficient alternative to successive cancellation list (SCL) decoding of polar codes. Although AED has demonstrated superior performance for…

Information Theory · Computer Science 2023-05-03 Marvin Geiselhart , Jannis Clausius , Stephan ten Brink

The stochastic inverse eigenvalue problem aims to reconstruct a stochastic matrix from its spectrum. While there exists a large literature on the existence of solutions for special settings, there are only few numerical solution methods…

Numerical Analysis · Mathematics 2020-04-17 Gabriele Steidl , Maximilian Winkler

We present a real-space adaptive-coordinate method, which combines the advantages of the finite-difference approach with the accuracy and flexibility of the adaptive coordinate method. The discretized Kohn-Sham equations are written in…

mtrl-th · Physics 2009-10-28 Francois Gygi , Giulia Galli

In this article, we propose a two-grid based adaptive proper orthogonal decomposition (POD) method to solve the time dependent partial differential equations. Based on the error obtained in the coarse grid, we propose an error indicator for…

Numerical Analysis · Mathematics 2020-07-24 Xiaoying Dai , Xiong Kuang , Jack Xin , Aihui Zhou

FOXTAIL is a new hybrid magnetohydrodynamic-kinetic code used to describe interactions between energetic particles and Alfv\'en eigenmodes in tokamaks with realistic geometries. The code simulates the nonlinear dynamics of the amplitudes of…

Plasma Physics · Physics 2017-04-05 Emmi Tholerus , Thomas Johnson , Torbjörn Hellsten

We develop a new, efficient, and accurate method to simulate frequency-domain borehole electromagnetic (EM) measurements acquired in the presence of three-dimensional (3D) variations of the anisotropic subsurface conductivity. The method is…

We present a paradigm for developing arbitrarily high order, linear, unconditionally energy stable numerical algorithms for gradient flow models. We apply the energy quadratization (EQ) technique to reformulate the general gradient flow…

Numerical Analysis · Mathematics 2020-07-15 Yuezheng Gong , Jia Zhao , Qi Wang

3D free boundary equilibrium computations have recently been used to model external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD stability codes, and nonlinear analytic theory [Kleiner et al, PPCF 61 084005…

This paper aims to present a fairly accessible generalization of several symmetric Gauss-Seidel decomposition based multi-block proximal alternating direction methods of multipliers (ADMMs) for convex composite optimization problems. The…

Optimization and Control · Mathematics 2020-06-09 Liang Chen , Defeng Sun , Kim-Chuan Toh , Ning Zhang

We present a new efficient analytical approximation scheme to two-point boundary value problems of ordinary differential equations (ODEs) adapted to the study of the derivative expansion of the exact renormalization group equations. It is…

High Energy Physics - Theory · Physics 2008-11-26 C. Bervillier , B. Boisseau , H. Giacomini

A new code, named MAP, is written in Fortran language for magnetohydrodynamics (MHD) calculation with the adaptive mesh refinement (AMR) and Message Passing Interface (MPI) parallelization. There are several optional numerical schemes for…

Instrumentation and Methods for Astrophysics · Physics 2012-04-27 R. L. Jiang , C. Fang , P. F. Chen

We propose and investigate a novel solution strategy to efficiently and accurately compute approximate solutions to semilinear optimal control problems, focusing on the optimal control of phase field formulations of geometric evolution…

Optimization and Control · Mathematics 2017-02-01 F. Yang , C. Venkataraman , V. Styles , A. Madzvamuse

The high-precision solution of the radial Dirac equation is fundamental to relativistic quantum chemistry, essential for reliable pseudopotential generation and all-electron electronic structure methods. However, standard basis-set…

Numerical Analysis · Mathematics 2026-04-14 Sheng Chen , Sihong Shao , Shuai Wu

We describe a magnetohydrodynamic (MHD) constrained energy functional for equilibrium calculations that combines the topological constraints of ideal MHD with elements of Taylor relaxation. Extremizing states allow for partially chaotic…

Plasma Physics · Physics 2012-04-03 S. R. Hudson , R. L. Dewar , M. J. Hole , M. McGann

We present two efficient numerical methods for susceptibility artifact correction applicable in Echo Planar Imaging (EPI), an ultra fast Magnetic Resonance Imaging (MRI) technique widely used in clinical applications. Both methods address a…

Optimization and Control · Mathematics 2016-11-23 Jan Macdonald , Lars Ruthotto

A novel and highly efficient computational framework for reconstructing binary-type images suitable for models of various complexity seen in diverse biomedical applications is developed and validated. Efficiency in computational speed and…

Optimization and Control · Mathematics 2024-02-09 Paul R. Arbic , Vladislav Bukshtynov

We consider an adaptive algorithm for finite element methods for the isogeometric analysis (IGAFEM) of elliptic (possibly non-symmetric) second-order partial differential equations. We employ analysis-suitable T-splines of arbitrary odd…

Numerical Analysis · Mathematics 2020-09-07 Gregor Gantner , Dirk Praetorius

Quantum error correction (QEC) is essential for realizing fault-tolerant quantum computation. Current QEC controllers execute all scheduled syndrome (parity-bit) measurement rounds before decoding, even when early syndrome data indicates…

Quantum Physics · Physics 2026-02-20 Sanidhay Bhambay , Prakash Murali , Neil Walton , Thirupathaiah Vasantam