New paper on Waveform Relaxation for Multiscale Problems

jcp Our paper on Waveform Relaxation for the Computational Homogenization of Multiscale Magnetoquasistatic Problems (Innocent Niyonzima, Christophe Geuzaine, Sebastian Schöps) has been accepted by JCP:
This paper proposes the application of the waveform relaxation method to the homogenization of multiscale magnetoquasistatic problems. In the monolithic heterogeneous multiscale method, the nonlinear macroscale problem is solved using the Newton–Raphson scheme. The resolution of many mesoscale problems per Gauss point allows to compute the homogenized constitutive law and its derivative by finite differences. In the proposed approach, the macroscale problem and the mesoscale problems are weakly coupled and solved separately using the finite element method on time intervals for several waveform relaxation iterations. The exchange of information between both problems is still carried out using the heterogeneous multiscale method. However, the partial derivatives can now be evaluated exactly by solving only one mesoscale problem per Gauss point. Continue reading →

How to build GNU Octave with Qt5 on the Mac

1503512The graphical user interface of Octave 4.0 can only be compiled with Qt4. Homebrew is dropping 4.x support and moving towards 5.x. Several Octave dependencies have already been updated (e.g. Qscintilla2, see e.g. this issue. However, the upcoming Octave 4.2 (release is scheduled for September 2016) will have full Qt5 as discussed here.

The standard installation uses the command line interface. If you need Octave with graphical user interface then this should work
brew update 
brew upgrade #to get the latest qscintilla
brew install octave --with-gui --HEAD
Update: The post has been edited on Aug 20 since the new formula is now available in homebrew’s science repository.

Three presentation from CE@TUDa at ECMI 2016

ecmi2016The 19th European Conference on Mathematics for Industry (ECMI 2016) in Santiago is over. We organized one minisymposium and contributed three talks in the minisymposia You find summaries of the talks in the book of abstracts.

Invited Talk by Sergej Rjasanow on FEM on polyhedral meshes

Prof. Dr. Sergej Rjasanow from Saarland University talks on Finite Element Method on uniform and adaptive polygonal and polyhedral meshes at 30 May 2016, 16:15–17:45; Location: S2|17-103. From the abstract
In the development of numerical methods to solve boundary value problems the requirement of flexible mesh handling gains more and more importance. The BEM-based finite element method [1] is one of the new promising strategies which yield conforming approximations on polygonal and polyhedral meshes, respectively. Continue reading →

Darmstadt is well prepared for the future…

Prognos_Darmstadt According to a recent study of Prognos Darmstadt is the city with the 9th highest potential in Germany. In a similar study of IW Consult Darmstadt was even number one. The reasons were similar, for example: many young and well educated inhabitants with background in mathematics, natural sciences or engineering. Wirtschaftswoche said “Hier profitiert Darmstadt von seiner 1877 gegründeten Technischen Universität. Hinzu kommt die Sogwirkung auf High Potentials durch drei Fraunhofer-Institute und das GSI Helmholtzzentrum für Schwerionenforschung, das gerade den Bau eines gigantischen Teilchenbeschleunigers vorbereitet.