Multigrid-reduction-in-time for Eddy Current problems

Parallel-in-time methods have shown success for reducing the simulation time of many time-dependent problems. Here, we consider applying the multigrid-reduction-in-time (MGRIT) algorithm to a voltage-driven eddy current model problem.Comment: Contribution from GAMM 2019 conferenc

Parallel-in-Time Simulation of an Electrical Machine using MGRIT

We apply the multigrid-reduction-in-time (MGRIT) algorithm to an eddy current simulation of a two-dimensional induction machine supplied by a pulse-width-modulation signal. To resolve the fast-switching excitations, small time steps are needed, such that parallelization in time becomes highly relevant for reducing the simulation time. The MGRIT algorithm is well suited for introducing time parallelism in the simulation of electrical machines using existing application codes, as MGRIT is a non-intrusive approach that essentially uses the same time integrator as a traditional time-stepping algorithm. We investigate effects of spatial coarsening on MGRIT convergence when applied to two numerical models of an induction machine, one with linear material laws and a full nonlinear model. Parallel results demonstrate significant speedup in the simulation time compared to sequential time stepping, even for moderate numbers of processors.Comment: 14 page

La cultura científica, la percepción pública y el caso de la biotecnología

Ponencia presentada en el seminario "La cultura científica en la sociedad de la información" (Oviedo, 30 de mayo a de junio de 2002), organizado por el Observatorio de Cultura Científica de la Universidad de Oviedo.Peer reviewe

A Place to Stand

The first part of a novel submitted to the University of Canterbury to fulfil the requirements of the degree of Master of Fine Arts in Creative Writing

Modellierung der praktischen Rolle in Verhandlungen mit einem erweiterten Verfahren des fallbasierten Schließens

Der vorliegende Text beruht auf einem Vortrag, der auf dem Treffen des Schwerpunktprogramms "Sozionik" (SP1077) der Deutschen Forschungsgemeinschaft vom 20.-23. Juni 2002 in Seeon gehalten wurde. Die Autoren stellen die Bedeutung von Verhandlungen in Organisationen und deren Modellierung in einem Multiagentensystem dar, wobei exemplarisch die Organisation Krankenhaus betrachtet wird. Nach soziologischen Überlegungen zu einem Multiagentensystem in Bezug auf Verhandlungen wird die Modellierung und Berechnung von Verhandlung vorgestellt. Anschließend wird der Vorschlag, das Verfahren des fallbasierten Schließens (FBS) zu erweitern, erläutert. Dabei wird in einzelnen Unterkapiteln zuerst ein kurzer Überblick über das FBS gegeben und anschließend die konkrete Anwendung im interdisziplinären Forschungsprojekt "Integration kooperationsfähiger Agenten in komplexen Organisationen" (INKA) aufgezeigt. (ICI

THE SuperTIGER Instrument: Measurement of Elemental Abundances of Ultra-Heavy Galactic Cosmic Rays

The SuperTIGER (Super Trans-Iron Galactic Element Recorder) instrument was developed to measure the abundances of galactic cosmic-ray elements from Ne-10 to Zr-40 with individual element resolution and the high statistics needed to test models of cosmic-ray origins. SuperTIGER also makes exploratory measurements of the abundances of elements with 40 or = 10, including approx.1300 with Z > 29 and approx.60 with Z > 49. Here, we describe the instrument, the methods of charge identification employed, the SuperTIGER balloon flight, and the instrument performance

Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised protons

Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise. © 2015