Publications related to Romberg's method

QuNex-An integrative platform for reproducible neuroimaging analytics

IntroductionNeuroimaging technology has experienced explosive growth and transformed the study of neural mechanisms across health and disease. However, given the diversity of sophisticated tools for handling neuroimaging data, the field faces challenges in ...

FRONTIERS MEDIA SA2023

lifex-ep: a robust and efficient software for cardiac electrophysiology simulations

Alfio Quarteroni, Francesco Regazzoni, Stefano Pagani, Marco Fedele

Background: Simulating the cardiac function requires the numerical solution of multi-physics and multi-scale mathematical models. This underscores the need for streamlined, accurate, and high-performance computational tools. Despite the dedicated endeavors ...

BMC2023

A numerical investigation of multi space reduced basis preconditioners for parametrized elliptic advection-diffusion equations

Simone Deparis, Andrea Manzoni, Niccolò Dal Santo

We analyze the numerical performance of a preconditioning technique recently proposed in [1] for the efficient solution of parametrized linear systems arising from the finite element (FE) discretization of parameter-dependent elliptic partial differential ...

Walter de Gruyter GmbH2017

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

Verification and validation procedures with applications to plasma-edge turbulence simulations

Fabio Riva

Understanding the plasma dynamics in tokamaks is of fundamental importance to reliably predict the performances of future fusion devices. Because of the complex phenomena at play, state-of-the-art simulation codes are needed to investigate the plasma dynam ...

EPFL2017

Accurate, Stable and Efficient Modal Calculations of Photoelectrically Useful Absorption in Lamellar Metallic and Semiconductor Diffraction Gratings

David Isaak Gablinger

Solar energy has seen tremendous advances in the past years. For thin film photovoltaics, which use less of the expensive semiconductor materials, insufficient light absorption can be a limiting factor. It is hoped that by using diffractive optics to impro ...

EPFL2016

Convergence of quasi-optimal sparse-grid approximation of Hilbert-space-valued functions: application to random elliptic PDEs

Fabio Nobile, Lorenzo Tamellini

In this work we provide a convergence analysis for the quasi-optimal version of the sparse-grids stochastic collocation method we presented in a previous work: “On the optimal polynomial approximation of stochastic PDEs by Galerkin and collocation methods” ...

Springer2016

Comparison of Clenshaw-Curtis and Leja Quasi-Optimal Sparse Grids for the Approximation of Random PDEs

Fabio Nobile, Lorenzo Tamellini

In this work we compare different families of nested quadrature points, i.e. the classic Clenshaw-Curtis and various kinds of Leja points, in the context of the quasi-optimal sparse grid approximation of random elliptic PDEs. Numerical evidence suggests th ...

Springer2015

Queue Profile Estimation in Congested Urban Networks with Probe Data

Nikolaos Geroliminis, Mohsen Ramezani Ghalenoei

Queues at signalized intersections are the main cause of traffic delays and travel time variability in urban networks. In this article, we propose a method to estimate queue profiles that are traffic shockwave polygons in the time-space plane describing th ...

2015

Verification methodology for plasma simulations and application to a scrape-off layer turbulence code

Paolo Ricci, Sébastien Jolliet, Joaquim Loizu Cisquella, Federico David Halpern, Fabio Riva, Annamaria Mosetto

Bridging the gap between plasma physics and other scientific domains, in particular, the computational fluid dynamics community, a general, rigorous, and simple-to-apply methodology is presented for both the verification of the correct implementation of th ...

American Institute of Physics2014

The weighted averages method for semi-infinite range integrals involving products of Bessel functions

Juan Ramon Mosig, Ruzica Golubovic

An efficient and accurate method, based on the weighted averages (WA) extrapolation technique, is presented for the evaluation of semi-infinite range integrals involving products of Bessel functions of arbitrary order. The method requires splitting the int ...

Institute of Electrical and Electronics Engineers2013

A higher-order numerical framework for stochastic simulation of chemical reaction systems

Background: In this paper, we present a framework for improving the accuracy of fixed-step methods for Monte Carlo simulation of discrete stochastic chemical kinetics. Stochasticity is ubiquitous in many areas of cell biology, for example in gene regulatio ...

Biomed Central Ltd2012

Optimization Problem Coupled with Differential Equations: A Numerical Algorithm Mixing an Interior-Point Method and Event Detection

Jacques Rappaz, Alexandre Caboussat, Christian Landry

The numerical analysis of a dynamic constrained optimization problem is presented. It consists of a global minimization problem that is coupled with a system of ordinary differential equations. The activation and the deactivation of inequality constraints ...

2010

Contribution to Integral Equation Techniques for Solving Electromagnetic Problems

Sergio Lopez Pena

Surface Mixed Potential Integral Equation (MPIE) formulations together with the Method of Moments (MoM) are widely used to solve electromagnetic problems. An accurate evaluation of the Green functions (GF) associated to the integral equation and of the cou ...

EPFL2010

Analysis of a Novel BAW-based Power Amplifier

Christian Enz

A novel MEMS-based co-designed power amplifier is presented. To introduce the analysis and evaluate the impact of realistic on-chip losses, two design approaches are discussed and compared. Then the study of the novel circuit, based on the integration of h ...

2009

Numerical analysis of optimization-constrained differential equations : applications to atmospheric chemistry

Chantal Landry

The modeling of a system composed by a gas phase and organic aerosol particles, and its numerical resolution are studied. The gas-aerosol system is modeled by ordinary differential equations coupled with a mixed-constrained optimization problem. This coupl ...

EPFL2009

Spectral element approximation of the incompressible Navier-Stokes equations in a moving domain and applications

Gonçalo Pena

In this thesis we address the numerical approximation of the incompressible Navier-Stokes equations evolving in a moving domain with the spectral element method and high order time integrators. First, we present the spectral element method and the basic to ...

EPFL2009

Sound Field Analysis Along a Circle and its Application to HRTF Interpolation

Martin Vetterli, Christof Faller, Luciano Sbaiz, Thibaut Ajdler

The sampling and interpolation of a sound field in two and three dimensions along a circle is discussed. The Fourier domain representation of the sound field is used, and an angular sampling theorem is developed for the sampling of the sound field along a ...

2008

General state-space models : randomised quasi-Monte Carlo methods for general Kalman recursion

Thomas Gsponer

In time series analysis state-space models provide a wide and flexible class. The basic idea is to describe an unobservable phenomenon of interest on the basis of noisy data. The first constituent of such a model is the so-called state equation, which char ...

EPFL2004

Analyse des erreurs dues à l'écoulement dans la mesure de débit par la méthode acoustique : approches expérimentale et numérique

The precise flow-rate measurement is a basic problem in the management and the exploitation of a hydraulic power-plant. The efficiency characterisation of an hydraulic machinery or of a water distribution net is linked to the accurate knowledge of the flow ...

EPFL1997