1,729 research outputs found
The Influence of the Asymptotic Regime on the RS-IMEX
No full textIn this work, we investigate the performance and explore the limits of a novel implicit-explicit splitting [6] for the efficient treatment of singularly perturbed ODEs. We consider a singularly perturbed ODE where, based on the choice of initial conditions, the unperturbed equation does not necessarily describe the behavior of
the perturbed one accurately. For the splitting presented in [6], this has a tremendous influence as it explicitly depends on the solution to the unperturbed equation. That this indeed poses a problem is shown numerically; but also the remedy of using the
’correct’ asymptotics is presented. Comparisons with a fully implicit and a standard implicit-explicit splitting are shown.The first author has been partially supported by the German Research Foundation (DFG) project NO 361/3-3, and the University of Hasselt in the framework of the BOF 2016
Jochen Cornelius-Bundschuh ist neuer Landesbischof der Badischen Landeskirche
No full textProf. Dr. Jochen Cornelius-Bundschuh, außerplanmäßiger Professor an der Theologischen Fakultät der Universität Heidelberg, ist neuer Landesbischof der Evangelischen Landeskirche in Baden. Campus-TV zeigt ihn im Gespräch mit Joachim Kaiser
A new stable splitting for singularly perturbed ODEs
No full textIn this publication, we consider IMEX methods applied to singularly perturbed ordinary differential equations. We introduce a new splitting into stiff and non-stiff parts that has a direct extension to systems of conservation laws and investigate its performance analytically and numerically. We show that this splitting can in some cases improve the order of convergence, demonstrating that the phenomenon of order reduction is not only a consequence of the method but also of the splitting.The authors would like to thank Sebastian Noelle for fruitful discussions. Furthermore, we would like to thank the anonymous referee for suggestions that helped improving the paper substantially. The second author has been partially supported by DFG project NO 361/3-3 (German Science Foundation)
An Interview with Matthew Kaiser on Competition and Play
No full textAn Interview with Matthew Kaiser on Competition and Play, by Sean Scanlan. Matthew Kaiser, the author of The World in Play: Portraits of a Victorian Concept (Stanford UP, 2012) says that “[c]ompetition is the disease from which modern life suffers,” and that “[c]ompetition is the only cure” for this suffering. This contradictory pairing seems to get at the heart of his thesis: play, as a totalizing, umbrella-like concept, emanates from a host of philosophical, political, and scientific work produced by Victorians who posed many of their ideas of play in sports metaphors, competitive logics, and narratives of struggle. Kaiser goes beyond the dichotomy of competition and play/competition or play, by stating “I’m interested in the totalizing potential of both concepts, the way that play, or competition for that matter, swallows the world whole, becomes in the minds of so many people, the organizing principle of reality, whether of culture or nature or consciousness, or of all three.
A high-order method for weakly compressible flows
No full textAbstractIn this work, we introduce an IMEX discontinuous Galerkin solver for the weakly compressible isentropic Euler equations. The splitting needed for the IMEX temporal integration is based on the recently introducedreference solutionsplitting [32, 52], which makes use of theincompressiblesolution. We show that the overall method isasymptotic preserving. Numerical results show the performance of the algorithm which is stable under a convective CFL condition and does not show any order degradation.</jats:p
Hoock (Jochen), Jeannin (Pierre) & Kaiser (Wolfgang), éds. Ars Mercatoria. Manuels et traités à l'usage des marchands.
No full textMorineau Michel. Hoock (Jochen), Jeannin (Pierre) & Kaiser (Wolfgang), éds. Ars Mercatoria. Manuels et traités à l'usage des marchands.. In: Revue belge de philologie et d'histoire, tome 81, fasc. 2, 2003. Histoire medievale, moderne et contemporaine - Middeleeuwse. moderne en hedendaagse geschiedenis. pp. 518-519
Kurt Nowak, Kirchliche Zeitgeschichte interdisziplinär. Beiträge 1984-2001. Herausgegeben von Jochen-Christoph Kaiser, Suttgart, Kohlhammer, 2002 (Konfession und Gesellschaft ; 25)
No full textArnold Matthieu. Kurt Nowak, Kirchliche Zeitgeschichte interdisziplinär. Beiträge 1984-2001. Herausgegeben von Jochen-Christoph Kaiser, Suttgart, Kohlhammer, 2002 (Konfession und Gesellschaft ; 25). In: Revue d'histoire et de philosophie religieuses, 84e année n°3, Juillet-Septembre 2004. pp. 379-380
Kurt Nowak, Kirchliche Zeitgeschichte interdisziplinär. Beiträge 1984-2001. Herausgegeben von Jochen-Christoph Kaiser, Suttgart, Kohlhammer, 2002 (Konfession und Gesellschaft ; 25)
No full textArnold Matthieu. Kurt Nowak, Kirchliche Zeitgeschichte interdisziplinär. Beiträge 1984-2001. Herausgegeben von Jochen-Christoph Kaiser, Suttgart, Kohlhammer, 2002 (Konfession und Gesellschaft ; 25). In: Revue d'histoire et de philosophie religieuses, 84e année n°3, Juillet-Septembre 2004. pp. 379-380
Die Relevanz der Reformation und das Relevanzdilemma der Reformationshistoriographie - ein Räsonnement
No full textEfficient high-order discontinuous Galerkin computations of low Mach number flows
No full textWe consider the efficient approximation of low Mach number flows by a high-order scheme, coupling a discontinuous Galerkin (DG) discretization in space with an implicit/explicit (IMEX) discretization in time. The splitting into linear implicit and nonlinear explicit parts relies heavily on the incompressible solution. The method has been originally developed for a singularly perturbed ODE and applied to the isentropic Euler equations. Here, we improve, extend, and investigate the so-called RS-IMEX splitting method. The resulting scheme can cope with a broader range of Mach numbers without running into roundoff errors, it is extended to realistic physical boundary conditions, and it is shown to be highly efficient in comparison to more standard solution techniques.Jonas Zeifang has been supported by the German Research Foundation (DFG)
through the International Research Training Group GRK 2160: Droplet Interaction
Technologies (DROPIT). The computations with the FLEXI framework have been
conducted on the Cray XC40 at the High Performance Computing Center Stuttgart
under the hpcdg project.
Klaus Kaiser has been partially supported by the German Research Foundation
(DFG) through project NO 361/6-1; his study was supported by the Special Research
Fund (BOF) of Hasselt Universit
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