Dr. Lorenz John
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Research interests
- Mixed and Stabilized Finite Element Methods
- Multigrid Methods and Preconditioners
- PDE Constrained Optimization
- Computational Fluid Dynamics
News
- SPPEXA Symposium 2016, Jan. 25-27 2016, Munich, Germany.
- Workshop on advanced numerical techniques in biomedical computing, Dec. 3 2015, Oslo, Norway.
- Minisymposia: Fast solvers for saddle-point problems with applications in fluid dynamics at ENUMATH, Sep. 14-18 2015, Ankara, Turkey.
Publications
- L. John, U. Rüde, B. Wohlmuth, W. Zulehner: On the analysis of block smoothers for saddle point problems. preprint
- B. Gmeiner, M. Huber, L. John, U. Rüde, B. Wohlmuth: A quantitative performance study for Stokes solvers at the extreme scale. Journal of Computational Science, published online, 2016. link, preprint
- L. John, M. Neilan, I. Smears. Stable Discontinuous Galerkin FEM without penalty parameters, in B. Karasözen et al. (eds.), Numerical Mathematics and Advanced Applications ENUMATH 2015, Lecture Notes in Computational Science and Engineering 112, 165-173, 2016. pdf, preprint
- S. Bauer, H.-P. Bunge, D. Drzisga, B. Gmeiner, M. Huber, L. John, M. Mohr, U. Rüde, H. Stengel, C. Waluga, J. Weismüller, G. Wellein, M. Wittmann, B. Wohlmuth. Hybrid parallel multigrid methods for geodynamical simulations, in H.-J. Bungartz et al. (eds.), Software for Exascale Computing - SPPEXA 2013-2015, Lecture Notes in Computational Science and Engineering 113, 211-235, 2016. link, pdf
- U. Rüde, B. Gmeiner, D. Bartuschat, B. Wohlmuth, C. Waluga, M. Huber, L. John, H.-P. Bunge, J. Weismüller, S. Baumann, M. Mohr TerraNeo - Integrated Co-Design of an Exascale Earth Mantle Modeling Framework. inSiDE, spring 2016, vol. 14(1), pp. 78-81. pdf
- B. Gmeiner, M. Huber, L. John, U. Rüde, C. Waluga, B. Wohlmuth: Massively parallel large scale Stokes flow simulation. NIC Series Vol. 48, pp. 333-341, 2016. pdf
- J. Weismüller, B. Gmeiner, S. Ghelichkhan, M. Huber, L. John, B. Wohlmuth, U. Rüde, H.-P. Bunge. Fast asthenosphere motion in high-resolution global mantle flow models. Geophys. Res. Lett., 2015. link
- L. John, P. Pustejovska, U. Rüde, B. Wohlmuth: Energy-Corrected Finite Element Methods for the Stokes system. IMA Journal of Numerical Analysis, published online, 2016. link, preprint
- M. Huber, L. John, P. Pustejovska, U. Rüde, C. Waluga, B. Wohlmuth: Solution Techniques for the Stokes System: A priori and a posteriori modifications, resilient algorithms. Proceedings of the 8th International Congress on Industrial and Applied Mathematics, 109–134, Higher Ed. Press, Beijing, 2015. pdf
- L. John, O. Steinbach: Schur complement preconditioners for the biharmonic Dirichlet boundary value problem. pdf
- L. John, P. Pustejovska, O. Steinbach: On the influence of the wall shear stress vector form on hemodynamic indicators. pdf
Books
- L. John: Optimal boundary control in energy spaces. Preconditioning and applications. Monographic Series TU Graz, Computation in Engineering and Science, vol. 24, 2014. link, pdf
Theses
- L. John: Optimal boundary control in energy spaces. Preconditioning and applications. Dissertation, Graz University of Technology, 2014.
- L. John: Stabilized finite element methods for Dirichlet boundary control problems in fluid mechanics. Master’s thesis, Graz University of Technology, 2011.
Honours and Awards
- 1st Place Best Student Poster Prize at the SIAM Conference on Computational Science and Engineering, Feb. 25 - Mar. 01 2013, Boston, USA.
- SIAM Student Travel Award 2013.
Teaching
- Winter Term 2016: Einführung in die Programmierung (MA 8003)
- Summer Term 2016: Numerik gewöhnlicher Differentialgleichungen (MA2304)
- Winter Term 2015: Parameter identification and inverse problems (MA5331) & Einführung in die Programmierung (MA 8003)
- Summer Term 2015: Lattice Boltzmann methods (MA5344)
- Winter Term 2014: Introduction to Programming (MA 8003)
- Summer Term 2014: Mathematics for Physicists 3