Publications related to Equation solving

FENNECS: a novel particle-in-cell code for simulating the formation of magnetized non-neutral plasmas trapped by electrodes of complex geometries

Stefano Alberti, Jean-Philippe Hogge, Joaquim Loizu Cisquella, Jérémy Genoud, Francesco Romano, Guillaume Michel Le Bars

This paper presents the new 2D electrostatic particle -in -cell code FENNECS developed to study the formation of magnetized non -neutral plasmas in geometries with azimuthal symmetry. This code has been developed in the domain of gyrotron electron gun desi ...

2024

High-frequency response of a hemispherical grounding electrode

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri

The lightning discharge current is characterized by a high-frequency spectrum extending from DC to about 10 MHz. The calculation of the grounding impedance is one of the most important aspects of designing lightning protection systems. The search for analy ...

Elsevier2024

Divertor detachment and reattachment with mixed impurity seeding on ASDEX Upgrade

Olivier Claude Martin Février

Using newly developed spectroscopic models to measure the divertor concentration of Ne and Ar, it is shown that the experimental detachment threshold on ASDEX Upgrade with Ar-only and mixtures of Ar+N or Ne+N scales as expected in comparison with an analyt ...

IOP Publishing Ltd2023

An analytical solution of the isentropic vortex problem in the special relativistic magnetohydrodynamics

Junming Duan

The isentropic vortex problem is frequently solved to test the accuracy of numerical methods and verify corresponding code. Unfortunately, its existing solution was derived in the relativistic magnetohydrodynamics by numerically solving an ordinary differe ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Modeling Supply Chain Disruptions: A Network Flow Approach

René Yves Glogg

Globalization, outsourcing and cost optimization have all contributed to increased supply chain vulnerability, yet our understanding of effective mitigation strategies remains limited. In our research, we study the effects of disruptions on supply chain ne ...

EPFL2021

Three-dimensional fluid-driven stable frictional ruptures

Brice Tanguy Alphonse Lecampion, Alexis Alejandro Sáez Uribe

We investigate the quasi-static growth of a fluid-driven frictional shear crack that propagates in mixed mode (II+III) on a planar fault interface that separates two identical half-spaces of a three-dimensional solid. The fault interface is characterized b ...

2022

Large Steps in Inverse Rendering of Geometry

Wenzel Alban Jakob, Baptiste Alexandre Marie Philippe Claude Nicolet

Inverse reconstruction from images is a central problem in many scientific and engineering disciplines. Recent progress on differentiable rendering has led to methods that can efficiently differentiate the full process of image formation with respect to mi ...

ASSOC COMPUTING MACHINERY2021

Analogue computing with metamaterials

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad

Despite their widespread use for performing advanced computational tasks, digital signal processors suffer from several restrictions, including low speed, high power consumption and complexity, caused by costly analogue-to-digital converters. For this reas ...

2021

Apparent diffusion coefficient measured by diffusion MRI of moving and deforming domains

Jan Sickmann Hesthaven

The modeling of the diffusion MRI signal from moving and deforming organs such as the heart is challenging due to significant motion and deformation of the imaged medium during the signal acquisition. Recently, a mathematical formulation of the Bloch-Torre ...

Academic Press Inc - Elsevier Science2020

A mathematical model of the human heart

Alfio Quarteroni

In this paper, we present a mathematical model able to simulate the cardiac function. We first describe the basic physical principles behind the mathematical equations, then we illustrate a few examples of application to problems of clinical relevance. ...

PENSIERO SCIENTIFICO EDITOR2020

Pocket guide to solve inverse problems with GlobalBioIm

Michaël Unser, Daniel Sage, Thanh-An Michel Pham, Laurène Donati, Emmanuel Emilien Louis Soubies, Ferréol Arnaud Marie Soulez, Michael Thompson McCann, Thomas Jean Debarre

GlobalBioIm is an open-source MATLAB (R) library for solving inverse problems. The library capitalizes on the strong commonalities between forward models to standardize the resolution of a wide range of imaging inverse problems. Endowed with an operator-al ...

2019

Generalized Optical Signal Processing Based on Multioperator Metasurfaces Synthesized by Susceptibility Tensors

Karim Achouri, Ali Momeni

This paper theoretically proposes a multichannel nonlocal metasurface computer characterized by generalized sheet transition conditions (GSTCs) and surface susceptibility tensors. The study explores polarization- and angle-multiplexed metasurfaces enabling ...

American Physical Society (APS)2019

A local discontinuous Galerkin gradient discretization method for linear and quasilinear elliptic equations

Assyr Abdulle, Giacomo Rosilho De Souza

A local weighted discontinuous Galerkin gradient discretization method for solving elliptic equations is introduced. The local scheme is based on a coarse grid and successively improves the solution solving a sequence of local elliptic problems in high gra ...

EDP SCIENCES S A2019

A methodology for the rigorous verification of Particle-in-Cell simulations

Paolo Ricci, Fabio Riva, Carrie Fiona Beadle

A methodology to perform a rigorous verification of Particle-in-Cell (PIC) simulations is presented, both for assessing the correct implementation of the model equations (code verification), and evaluating the numerical uncertainty affecting the simulation ...

American Institute of Physics2017

The viscous torsional pendulum

François Gallaire, Francesco Viola

A disk that is free to rotate about its axis and connected to a torsional spring behaves as a damped oscillator when twisted and released. The initial elastic energy is periodically turned to kinetic energy and it gets progressively dissipated by the visco ...

Academic Press Ltd- Elsevier Science Ltd2017

An Ohmic model for electrokinetic flows of binary asymmetric electrolytes

Alexandre Louis André Persat

The transport of electrolytes in electric fields is a ubiquitous phenomenon commonly harnessed in microfluidics. A classic leaky dielectric model for flow generated by electric fields accurately predicts electrohydrodynamic transport phenomenon but is vali ...

Elsevier Science London2016

Solving Stochastic AC Power Flow via Polynomial Chaos Expansion

Timm Faulwasser

The present contribution demonstrates the applicability of polynomial chaos expansion to stochastic (optimal) AC power flow problems that arise in the operation of power grids. For rectangular power flow, polynomial chaos expansion together with Galerkin p ...

IEEE2016

Truncated low-rank methods for solving general linear matrix equations

Daniel Kressner, Petar Sirkovic

This work is concerned with the numerical solution of large-scale linear matrix equations A1XB1T++AKXBKT=C. The most straightforward approach computes XRmxn from the solution of an mn x mn linear system, typically limiting the feasible values of m,n to a f ...

Wiley-Blackwell2015

Algebraic Cryptanalysis of Deterministic Symmetric Encryption

Petr Susil

Deterministic symmetric encryption is widely used in many cryptographic applications. The security of deterministic block and stream ciphers is evaluated using cryptanalysis. Cryptanalysis is divided into two main categories: statistical cryptanalysis and ...

EPFL2015

Interactive Learning from Unlabeled Instructions

Inaki Asier Iturrate Gil

Interactive learning deals with the problem of learning and solving tasks using human instructions. It is common in human-robot interaction, tutoring systems, and in human-computer interfaces such as brain-computer ones. In most cases, learning these tasks ...

2014