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Alumni of the DK CIM


 

Vincent De Groof, MSc Ph.D.
Current Affiliation: INTALES GmbH
Reserach area(s):
 Engineering Mathematics

Supervisor: Univ.-Prof. Dr. Michael Oberguggenberger 

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Thesis: Sampling-based sensitivity studies and iterative solvers in shell analysis

Thesis abstract:
The goal of the thesis is to speed up Monte Carlo simulations with non-smooth solutions. The path chosen to reach this goal is the investigation of different preconditioning schemes to enable the use of iterative solvers instead of direct solvers in the framework of multiple nearby systems that might be ill-conditioned. By a more efficient use of the available compuational resources, it is expected to reduce the calculation time of the set of nearby systems.

External cooperations:

  • Prof. Dr. Grasedyck, RWTH Aachen, Germany (Hierarchial Matrices)

Selected publications:

  • De Groof, V.; Oberguggenberger, M.; Haller, H.; Degenhardt, R.; Kling, A.; 2014, A case study of random field models applied to thinwalled composite cylinders in finite element analysis, In: Deodatis, G.; Ellingwood, B.R.; Frangopol, D.M.; Safety, Reliability, Risk and Life-Cycle Performance of Structures & Infrastructures, Boca Raton - [u.a.]: CRC Press, 2137-2144, ISBN: 9781138000865.
  • De Groof, V.; Oberguggenberger, M.; Prackwieser, M.; Schwarz, M.; 2013, Reliability analysis of shell structures, In: Barden, M., Ostermann, A., Scientific Computing @ uibk. Innsbruck: innsbruck university press (IUP), 39-42, ISBN: 978-3-902936-19-6.
  • De Groof, V.; Oberguggenberger, M.; Haller, H.; Degenhardt, R.; Kling, A.; 2012, Quantitative assessment of random field models in finite element buckling analyses of composite cylinders, In: Eberhardsteiner, J. et al. (eds.): Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), September 10-14, 2012, Vienna, AT, ISBN: 978-3-9502481-9-7.


Mag. Markus Haider, Ph.D.
Current Affiliation: Institute for Astro- and Particle Physics
Reserach area(s): Astrophysical Simulations

Applications group: Univ.-Prof. Dr. Sabine Schindler 

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Thesis: Simulations of Galaxy Clusters

Thesis abstract:
The PhD has been working on cosmological simulations of galaxy clusters. The main research project during the PhD was the creation of a versatile framework for simulating the dark matter evolution, galaxy formation and the intra-cluster medium hydrodynamics. During his PhD he also gained a lot of experience working with semi-analytical models of galaxy formation. Out of this PhD thesis several ongoing projects have been created.

Cooperations within DK CIM:

  • Harald Höller, Marcel Ritter, Dominik Steinhauser, Visualisation
  • Antti Koskela, Numerical Mathematics

Selected publications:

  • Benger, W.; Haider, M.; Stöckl, J.; Cosenza, B.; Ritter, M.; Steinhauser, D.; Höller, H.; 2012, Visualization Methods for Numerical Astrophysics, In: Kucuk, I.; Astrophysics. Rijeka: InTech, 259-286, DOI: 10.5772/32203.
  • Steinhauser, D.; Haider, M.; Kapferer, W.; Schindler, S.; 2012, Galaxies undergoing ram-pressure stripping: the influence of the bulge on morphology and star formation rate, Astronomy & Astrophysics 544, A54, DOI: 10.1051/0004-6361/201118311.
  •  Durret, F.; Laganá, T.F.; Haider, M, 2011, The merging cluster Abell 1758 revisited: multi-wavelength observations and numerical simulations, Astronomy & Astrophysics 529, A38, DOI: 10.1051/0004-6361/201015978.
  • Durret, F.; Lagana, T.; Adami, C.; Haider, M.; 2011, Pairs of clusters observed with XMM-Newton, The X-ray Universe 2011, Presentations of the Conference held in Berlin, Germany, 27-30 June 2011, online http://xmm.esac.esa.int/external/xmm_science/workshops/2011symposium/, id.204.
  • Stöckl, J.; Haider, M.; Steinhauser, D.; Riser, T.; 2010, Improved Visualisations of 3D Volumetric Data through Pointwise Phong Shading Based on Normal Mapping, In: Benger, W.; Gerndt, A.; Su, S.; Schoor, W.; Koppitz, M.; Kapferer, W.; Bischof, H.-P.; Di Pierro, M.; Proceedings of the 6th High-End Visulization Workshop, December 08-12, 2010, Obergurgl. Berlin: Lehmanns Media.


hellDipl.-Ing. Tobias Hell, Ph.D.
Current Affiliation: Department of Mathematics
Reserach area(s): Numerical Analysis, Applied Statistics

Methods group: Univ.-Prof. Dr. Alexander Ostermann 

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Thesis: Splitting methods: theory and application

Thesis abstract:
The first part of the thesis is devoted to the construction and investigation of efficient dimension splitting methods whereas the second part is concerned with the application of respective splitting methods in the context of modeling the dynamics of scattering of tritium and helium from graphite surfaces from a quantum mechanical point of view.

Cooperations within DK CIM:

  • Stefan Huber, Computational Chemistry
  • Phillip Gschwandtner, Computer Science

External cooperations:

  • ZAMG (Applied statistics)
  • UMIT (Applied statistics)
  • Krankenhaus der Barmherzigen Brüder Salzburg (Applied statistics)
  • Bartenbach (Numerical Analysis)

Selected publications:

  • Hell, T.; Ostermann, A.; Sandbichler, M.; 2015, Modification of dimension splitting methods- overcoming the order reduction due to corner singularities, IMA J. Numer. Anal. 35, 1078-1091, DOI 10.1093/imanum/dru030.
  • Hell, T.; Ostermann, A.; 2014, Compatibility conditions for Dirichlet and Neumann problems of Poisson's equation on a rectangle, Journal of Mathematical Analysis and Applications 12/2014, 420(2), 1005–1023, DOI: 10.1016/j.jmaa.2014.06.034.
  • Weiss, H.; Brunner, W.; Biebl, M.; Schirnhofer, J.; Pimpl, K.; Mittermair, C.; Obrist, C.; Brunner, E.; Hell, T.; 2014, Wound Complications in 1145 Consecutive Transumbilical Single-Incision Laparoscopic Procedures, Annals of Surgery 259/1, 89-95.
  • Hell, T.; Ostermann, A.; Sandbichler, M.; 2014, Modification of dimension splitting methods – overcoming the order reduction due to corner singularities, IMA J. Numer. Anal. 35(3), 1078-1091, DOI: 10.1093/imanum/dru030. (2013). 
  • Hell, T.; Ostermann, A.; 2013, Compatibility conditions for Dirichlet and Neumann problems of Poisson's equation on a rectangle, J. Math. Anal. Appl. 420(2), 1005-1023, DOI: 10.1016/j.jmaa.2014.06.034.


undefinedMag. Stefan Huber, Ph.D.
Current Affiliation: Institute of Ion Physics and Applied Physics
Reserach area(s): Quantum Chemistry, Physical Chemistry, Structural Chemistry

Applications group: A. Univ.-Prof. Dr. Michael Probst

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Thesis: Materials and Nanosystems: Interdisciplinary Computational Modeling at Multiple Scales

Thesis abstract:
Molecular systems are investigated at multiple scales. Quantum chemical methods are used ranging from ab-initio over DFT and approximate DFT to classical force-field approaches. The findings comprise e.g. the effect of deformation and/or particle impact on molecular and/or surface properties, a better understanding of surface stabilization via the introduction of defects, dynamic and thermal properties of metal nanowires. 

Cooperations within DK CIM:

  • Silvia Öttl, Astrophysics
  • Tobias Hell, Numerical Mathematics
  • Marcel Ritter, Faculty of Civil Engineering
  • Antti Koskela, Numerical Mathematics
  • Alexander Kaiser, Computational Chemistry

External cooperations:

  • Prof. Kersti Hermansson, Uppsala University, Kingdom of Sweden (Theoretical inoragnic chemistry)
  • Dr. Peter Broqvist, Uppsala University, Kingdom of Sweden (DFT and approximate DFT methods)
  • Prof. Jan Urban, Comenius University Bratislava, Slovakia (Nuclear fusion research)
  • Prof. Miroslav Urban, Comenius University Bratislava, Slovakia (Ab-initio methods, benchmark calculations)
  • Prof. Ivan Cernusak, Comenius University Bratislava, Slovakia (Ab-initio methods, benchmark calculations)
  • Prof. Jumras Limtrakul, Thailand (Nanotechnology)
  • Prof. Tatsuya Tsukuda, Japan (Materials science)
  • Prof. Renat Nazmutdinov, Russia (Solution chemistry, electrochemistry)
  • Dr. Andreas Mauracher (Computational molecular structure)
  • Prof. Paul Scheier (Ion Physics)
  • Prof. Stephan Denifl (Biophysics)
  • Dr. Violaine Vizcaino, France (Ion Physics and Biophysics)
  • Prof. Andrew Ellis, Leicster University, UK (Cluster Physics)
  • Dr. Chris A. Mayhew, Birmingham University (Ion Physics, Explosives)

Selected publications:

  • Huber, S.E.; Mauracher, A.; Probst, M.; 2013, Permeation of low-Z atoms through carbon sheets: Density functional theory study on energy barriers and deformation effects, AIP Advances 3(12), 122104/1-19, DOI: 10.1063/1.4842495.
  • Puschnigg, B.; Huber, S.E.; Probst, M.; Tanzer, K.; Vizcaino, V.; Ferreira da Silva, F.; Scheier, P.; Limao-Vieira, P, Denifl, S.; 2013, Electron attachment to the dipeptide dialanine: influence of methylation on site selective dissociation reactions, Physical Chemistry Chemical Physics 15/11, 3834-3840, DOI: 10.1039/C3CP44230F.
  • Huber, S. E.; Hell, T.; Probst, M.; Ostermann, A.; 2013, Numerical investigation of the elastic scattering of hydrogen (isotopes) and helium at graphite (0001) surfaces at beam energies of 1 to 4 eV using a split-step Fourier method, Theoretical Chemistry Accounts 132/4, Art. 1337, DOI: 10.1007/s00214-013-1337-9.
  • Huber, S.E.; Warakulwit, C.; Limtrakul, J.; Tsukuda, T.; Probst, M.; 2012, Thermal stabilization of thin gold nanowires by surfactant-coating: a molecular dynamics study, Nanoscale 4/2, 585-590, DOI: 10.1039/c1nr11282a.
  • Huber, S.E.; Dalnodar, S. (= Öttl, S.;) Kausch, W.; Kimeswenger, S.; Probst, M.; 2012, Carbonic acid revisited: Vibrational spectra, energetics and the possibility of detecting an elusive molecule, AIP Advances 2/3, S. 032180, DOI: 10.1063/1.4755786.


hoellerMag. Harald Höller, Ph.D.
Current Affiliation: Private industry
Reserach area(s): Astrophysics

Applications group: Univ.-Prof. Dr. Sabine Schindler 

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Thesis: Numerical Simulations of the Evolution of: Metal Enrichment in Galaxy Clusters

Thesis abstract:
We perform high resolution cosmological simulations of galaxy clusters in order to study the dynamics of the intra cluster medium on various scales as well as the chemical evolution due to stellar nucleosynthesis. Our simulation setup allows to model the necessary subgrid-physics (processes that take place way below the resolution level of these simulations) in a sophisticated way - first and foremost by employing the semi-analytical (SAM) galaxy formation model Galacticus which provides data that agree very well with actual astronomical observations. We present the development of an interface between the SAM and our hydrodynamical code FLASH in order to model the feedback processes that enrich the intra-cluster medium properly. We present results from cosmological simulations of galaxy clusters with focus on the study of the kinetic state of these objects as well as the constraints we are able to pose on galactic outflows from comparing our results to observations of the intra cluster medium.

Cooperations within DK CIM:

  • Antti Koskela, Mathematics

External cooperations:

  • Prof. Andrew Benson, Carnegie Institution of Science, California, USA (Astrophysics)
  • Dr. Wolfram Schmidt, Universität Göttigen, Germany (Astrophysics)
  • Dr. Lorenzo Lovisari, Agelander Insitut Bonn, Germany (Astrophysics)

Selected publications:

  • Höller, H.; Koskela, A.; Benger, W.; Dorfi, E.; 2014, Differential Geometrically Consistent Artificial Viscosity in Curvillinear Coordinates, Journal of Computational Physics, arXiv:1304.6029v2.
  • Benger, W.; Haider, M.; Stöckl, J.; Cosenza, B.; Ritter, M.; Steinhauser, D.; Höller, H.; 2012, Visualization Methods for Numerical Astrophysics, In: Kucuk, I.; Astrophysics, Rijeka, DOI: 10.5772/32203.
  • Höller, H.; Haider, M.; Stöckl, J.; Schindler, S.; 2013, Chemical tracking of galactic feedback processes in cosmological simulations, In: Barden, M.; Ostermann, A.; Scientific Computing @ uibk. Innsbruck, innsbruck university press (IUP) (= SC SERIES, 1), 59-63, ISBN 978-3-902936-19-6.


alexander_kaiserDipl.-Ing. Alexander Kaiser, Ph.D.
Current Affiliation: Institute of Ion Physics and Applied Physics
Reserach area(s): Quantum and classical simulations of molecular clusters
in vacuum and on surfaces
Applications group: A. Univ.-Prof. Dr. Michael Probst 

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Thesis: Quantum and Classical Simulations of Fullerene-Complexes in Vacuum and on Surfaces

Thesis abstract:
The aim of this work is to simulate molecular clustering in different environments with quantum chemical methods and by means of classical molecular dynamics to understand physical phenomena that are observed experimentally. The main part deals with the aggregation of hydrogen-rich molecules around complexes of fullerenes. The simulations give insight into the nature of different binding sites in the outer adsorption shells and in groove and dimple sites. Strong corrugation due to the curvature of fullerenes gives rise to new effects that cannot be observed on graphite or graphene, such as a commensurate phase, where each fullerene face is occupied by exactly one adsorbate methane or ethylene molecule. The simulations explain anomalies in the ion yields of mass spectrometric measurements on molecular clusters that were synthesized in helium nanodroplets in the laboratory of Innsbruck. In future applications of nanotechnology fullerenes will be deposited on surfaces. Therefore fullerene-surface interactions and induced surface reconstructions are also investigated. In a second research line molecular clustering is simulated in liquid solution, where clustering occurs not mainly due to van der Waals interactions but rather due to stronger hydrogen-bonds. Hydrogen-bonded clusters of ethylene-glycol and water mixtures and their lifetimes are calculated and visualized.

Cooperations within DK CIM:

  • Marcel Ritter, Visualization
  • Antti Koskela, Statistics and time integration
  • Stefan E. Huber, Quantum Chemistry
  • Tobias Hell, Time integration

External cooperations:

  • Prof. Paul Scheier, Institute for Ion Physics and Applied Physics (Ion Physics)
  • Prof. Olof Echt, Department of Physics, University of New Hampshire, Durham - New Hampshire, USA (Molecular Clusters)
  • Prof. Renat Nazmutdinov, Kazan National Reserach Technological University, Kazan, Russia (Dielectric spectroscopy, Electrochemistry)
  • Prof. Francesc Illas Riera, Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de, Barcelona, Spain (Quantum Chemistry and surfaces)
  • Prof. Frank Hagelberg, Department of Physics and Astronomy, East Tennessee State University, Johnson City, USA (Quantum Chemistry and Organic Photovolatics)
  • Prof. Harald Friedrich, Physik Department T30, Technische Universität München, Germany (Atomic physic)

Selected publications:

  • Kaiser A.; Vines F.; Illas F.; Ritter M.; Hagelberg F.; Probst M.; 2014, Vacancy Patterning and Patterning Vacancies: Controlled Self-Assembly of Fullerenes on Metal Surfaces, Nanoscale 6, 10850-10858, DOI: 10.1039/C4NR02717E.
  • Zoettl, S.; Kaiser, A.; Daxner, M.; Goulart, M.; Mauracher, A.; Probst, M.; Hagelberg, F.; Denifl, S.; Scheier, P.; Echt, O.; 2014, Ordered phases of ethylene adsorbed on charged fullerenes and their aggregates, Carbon 69, 206-220, DOI: 10.1016/j.carbon.2013.12.017.
  • Kaiser, A.; Ismailova, O.; Koskela, A.; Huber, S.E.; Ritter, M.; Cosenza, B.; Benger, W.; Nazmutdinov, R.; Probst, M.; 2014, Ethylene glycol revisited: Molecular dynamics simulations and visualization of the liquid and its hydrogen-bond network, Journal of Molecular Liquids 189, 20-29, DOI: 10.1016/j.molliq.2013.05.033.
  • Kaiser, A.; Ismailova, O.; Koskela, A.; Huber, S.E.; Ritter, M.; Cosenza, B.; Benger, W.; Nazmutdinov, R.; Probst, M.; 2014, Ethylene glycol revisited: Molecular dynamics simulations and visualization of the liquid and its hydrogen-bond network, Journal of Molecular Liquids 189, 20-29, DOI: 10.1016/j.molliq.2013.05.033.
  • Mauracher, A.; Kaiser, A.; Probst, M.; Zoettl, S.; Daxner, M.; Postler, J.; Goulart, M. M.; Zappa, F.; Bohme, D. K.; Scheier, P. , 2013, Decorating (C60)n+, n = 1-3, with CO2 at low temperatures: Sterically enhanced physisorption, International Journal of Mass Spectrometry 354-355, 271-274, DOI: doi:10.1016/j.ijms.2013.06.022.


koskelaAntti Koskela, MSc Ph.D.
Current Affiliation: Numerical Analysis, KTH Stockholm (Sweden)
Reserach area(s): Numerical simulations

Methods group: Univ.-Prof. Dr. Alexander Ostermann

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Thesis: Analysis and implementation of exponential integrators

Thesis abstract:
The thesis concentrates on the time integration of large stiff systems of ordinary differential equations, which result from semidiscretization of partial differential equations and are of the semilinear form u'(t) = Au(t)+g(u(t)). A class of numerical methods is introduced for the time integration of these problems, the so-called exponential Taylor methods, and the construction and analysis of these methods is performed using the Volterra integral equation which gives the exact solution for the semilinear ODE. When implementing exponential integrators one needs to evaluate the action of matrix functions (e.g. atrix exponential) on vectors. We consider using Krylov subspace methods for these problems, and introduce a so-called moment-matching Arnoldi iteration for computing linear combinations of productes of matrix functions and vectors. We show how to obtain a priori error bounds for the error of the moment-matching approximation using Cauchy’s integral formula, and how to derive a posteriori error estimates. The thesis discusses also the approximation of matrix functions for structured matrices and the approximation using non-orthogonal projections.

Cooperations within DK CIM:

  • Harald Höller, Astrophysics
  • Alexander Kaiser, Quantum Chemistry
  • Cristian Knapp, Plasma Physics 

External cooperations:

  • ANMC group, EPFL, Lausanne (Switzerland)
  • NLA group, Manchester (UK)
  • Numerics group, Aalto University, Helsinki (Finland)
  • Numerics group, KTH Stockholm, Stockholm (Sweden)

Selected publications:

  • Höller, H.; Koskela, A.; Dorfi, E.; Benger, W.; 2014, Artificial viscosity in comoving curvilinear coordinates: towards a differential geometrically consistent implicit advection scheme. Computational Astrophysics and Cosmology 2, Dezember 01, 2014, DOI: 10.1186/s40668-014-0002-6.
  • Höller, H.; Koskela, A.; Benger, W.; Dorfi, E.; Differential Geometrically Consistent Artificial Viscosity in Curvilinear Coordinates, Journal of Computational Physics, arXiv: 1304.6029v2.
  • Koskela, A.; 2014, Approximating the matrix exponential of an advection-diffusion operator using the incomplete orthogonalization method, Proceedings of the European Conference on Numerical Mathematics and Advanced Applications (Enumath) 2013, Lausanne, DOI: 10.1007/978-3-319-10705-9_34.
  • Koskela, A.; Ostermann, A.; 2014, A moment-matching Arnoldi iteration for linear combinations of φ functions, SIAM J. Matrix Anal. & Appl. 35, 1344-1363, DOI: 10.1137/130945156.
  • Koskela, A.; Ostermann, A.; 2013, Exponential Taylor methods: analysis and implementation, Computational and applied Mathematics 65, 487-499, DOI: DOI:10.1016/j.camwa.2012.06.004.


xin_maXin Ma, MSc Ph.D.
Current Affiliation: Private Industry
Reserach area(s): Computational Mechanics

Methods group: Univ.-Prof. Dr. Günter Hofstetter, 

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Thesis:  Large-scale 3D numerical simulations of geotechnical problems involving multi-phase soil models

Thesis abstract:
Large-scale 3D numerical simulations of tunneling involving multi-phase soil models are time-consuming because of the required large 3D domain to be meshed, the large number of excavation steps and securing steps to be simulated and the larger number of degrees of freedom (compared to single phase formulations). It is the aim to implement the developed three-phase formulation into an OpenSource FE-program (OpenSees) and to optimize the code with respect to its performance.

Selected publications:

  • Ma, X.; Gamnitzer, P.; Hofstetter, G.; 2013, Advanced Material Modeling and Parallel Computing for the Numerical Simulation of Multi Phase Problems in Geotechnical Engineering, Proceedings of 14th International Conference on Civil, Structural and Environmental Engineering Computing, Civil-Comp Press, Cagliari September 03-06, 2013, No. 204, ISBN: 978-1-905088-57-7.
  • Gamnitzer, P.; Ma, X.; Hofstetter, G.; 2012, Coupled solid-fluid FE-analysis considering partially saturated soils, Forschungskolloquium Baustatik-Baupraxis 12, September 18-21, 2012, Wesel, DE, DOI: 10.1002/gamm.201010003.

  

Dipl.-Ing. Lukas Moschen Ph.D.
Current Affiliation: FCP Vienna 
Reserach area(s): Earthquake Engineering and Structural Dynamics

Applications group: Univ.-Prof. Dr. Christoph Adam

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Thesis:  Contributions to the Probabilistic Seismic Assessment of Acceleration Demands in Buildings

Thesis abstract:
Financial loss of acceleration sensitive non-structural components (NSCs, such as medical equipment in a hospital), is characterized by the peak floor acceleration (PFA) demands, where the NSC is attached to the building. PFA demands can be estimated by response-history analysis, which is computationally expensive and requires years of experience in seismology, structural dynamics and probabilistic theory. Alternatively, a response spectrum method based on the normal stationary random vibration theory combines the deterministic information of the structure with the stochastic input of the ground motion. Benefits: (a) Basic knowledge of structural dynamics is required, and (b) reduction of computationally costs, i.e. response-history analysis is completely avoided.

External cooperations:

  • Dimitrios Vamvatsikos, Ass.-Prof. , School of Civil Engineering , National University of Athens, Greece
  • Ricardo A. Medina, Assoc.-Prof., Department of Civil Engineering, University of New Hampshire, US

Selected publications:

  • Moschen, L.; Medina, R. A..; Adam, C.; 2015, Vertical acceleration demands on nonstructural components in buildings. In: Papadrakakis, M.; Papadopoulos, V.; Plevris, V; eds: Proceedings 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, May 25-27, 2015, Crete, Greece, Vol. I, 1279-1299, ISBN: 978-960-00004-7-2.
  • Kampenhuber, D.; Moschen, L.; Pavel, F.; Sinkovic, K.; Radoslav, O.; Felja, I.; 2014. Project 3 – Damage assessment of a commercial building due to the main shock and after shock from the Van-Ercis earthquake 2011, In: Bauhaus Universität Weimar: Model Validation and Simulation - Vol. II. Graduate Courses for Structural Engineering Application, August 4-16, 2013. Weimar: Verlag der Bauhaus-Universität Weimar, 54-79, ISBN 978-3-95773-177-7.
  • Moschen, L.; Vamvatsikos, D.; Adam, C.; 2014, A modified response spectrum method for estimating peak floor acceleration demands in elastic regular frame structures, In: Second European Conference on Earthquake Engineering and Seismology (2ECEES). Istanbul: Özyeğin University, ISBN 978-605-62703-6-9.
  • Moschen, L.; Vamvatsikos, D.; Adam, C.; 2013, Towards a static pushover approximation of peak floor accelerations. In: Adam, Christoph; Heuer, Rudolf; Lenhardt, Wolfgang; Schranz, Christian: Proceedings Vienna Congress on Recent Advances in Earthquake Engineering and Structural Dynamics 2013 (VEESD 2013). August 29-30, 2013, Wien, Österreich. Wien: Österreichische Gesellschaft für Erdbebeningenieurwesen (OGE), ISBN 978-3-902749-04-8.
  • Moschen, L.; Adam, C.; 2012, Simplified seismic response prediction for vibration Prone non-structural components in inelastic frame structures, In: Sousa, O.; Carlos et al. (eds): Proceedings of the 15th WCEE - World Conference on Earthquake Engineering. Lisbon, September 24-28, 2012. International Association for Earthquake Engineering, No. 1013.

Presentation during the DK CIM Winterschool 2015

 

 

 

dalnodarSilvia Öttl, MSc Ph.D.
Current Affiliation: Institute for Astro- and Particle Physics
Reserach area(s):
Astrophysics, late stages of stellar Evolution

Applications group: A. Univ.-Prof. Dr. Stefan Kimeswenger

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Thesis: Computational and Observational Studies of Nebulae & Molecules - From a Molecular Perspective to the surroundings of Evolved Stars

Thesis abstract:
Observations and Modeling of Planetary Nebulae. The goal is to model a PN three-dimensional including all hydrodynamics and radiative transfer. We will also write proposals for more observing time of NGC 2438 and similar objects, even on bigger telescopes. A comparison between the observational data and our models will be done. 

Cooperations within DK CIM:

  • Stefan E. Huber, Quantum Chemistry
  • Antti Koskela, Numerical Analysis
  • Klaus Reitberger, High Energy Astrophysics

External cooperations:

  • Prof. Peter van Hoof, Royal Observatory of Belgium, Belgium (Astrophysics)
  • Prof. Albert Zijlstra, University of Manchester, UK (Astrophysics)

Selected publications:

  • Öttl, S.; 2014, The ionization state of the halo planetary nebula NGC 2438, Planetary Nebulae: An Eye to the Future, Proceedings of the International Astronomical Union, IAU Symposium, Volume 283, 338-339, DOI: 10.1017/S1743921312011313.
  • Proxauf, B.; Öttl, S.; Kimeswenger, S. 2014, Upgrading electron temperature and electron density diagnostic diagrams of forbidden line emission, Astronomy & Astrophysics, Vo. 561, Id.A10-4, DOI: 10.1051/0004-6361/201322581.
  • Huber, S.E.; Öttl, S.; Kimeswenger, S.; Probst, M.; Kausch, W.; 2013, Searching for carbonic acid, In: Barden, M.; Ostermann, A.; Scientific Computing @ uibk. Innsbruck; innsbruck university press (IUP) 73-75, ISBN 978-3-902936-19-6.
  • Niederwanger, F.; Kissmann, R.; Reitberger, K.; Öttl, S.; 2013, 3D Radiative Transfer models of Planetary Nebulae with CRONOS and CLOUDY, Proceedings of the ASYMMETRICAL PLANETARY NEBULAE VI Conference. November 4-8, 2013, Riviera Maya, Mexico. published online / Internetpublication.
  • Öttl, S.; Huber, S.E.; Kimeswenger S.; Probst, M.; 2013, Formation of Polycyclic Aromatic Hydrocarbons exhibiting (5,7)-member ring defects in Planetary Nebulae, Proceedings of the ASYMMETRICAL PLANETARY NEBULAE VI Conference. November 4-8, 2013, Riviera Maya, Mexico. published online / Internetpublication, 66.


reitbergerKlaus Reitberger, MSc Ph.D.
Current Affiliation: Institute for Astro- and Particle Physics
Reserach area(s): Astro particle physics, gamma-ray astronomy,
hydrodynamic modelling, binary systems
Applications group: Univ.-Prof. Dr. Olaf Reimer

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Thesis:  Observations and Numerical Studies of Gamma-Ray Emission in Colliding-Wind Binaries

Thesis abstract:
Massive stars in binary systems (as WR140, WR147 or η Carinae) have long been regarded as potential sources of high-energy gamma-rays. On the basis of a hydrodynamic discription of the stellar winds and their collision region, we solve a transport equation for high-energy particles accelerated at the shock fronts. Subsequently we compute gamma-ray emission spectra for inverse Compton scattering, bremsstrahlung and neutral pion decay.

Cooperations within DK CIM:

  • Siliva Öttl, Planetary nebulae

External cooperations:

  • Prof. Guillaume Dubus, Institut de Plantetologie et d'Astrophysque de Grenoble (France)
  • Fermi Large Area telescope

Selected publications:

  • Reitberger, K.; Kissmann, R.; Reimer, A.; Reimer, O.; Dubus, G.,2014, High-energy Particle Transport in Three-dimensional Hydrodynamic Models of Colliding-wind Binaries, The Astrophysical Journal 782/2, DOI: 10.1088/0004-637X/782/2/96.
  • Niederwanger, F.; Kissmann, R.; Reitberger, K.; Öttl, S.; 2013, 3D Radiative Transfer models of Planetary Nebulae with CRONOS and CLOUDY, Proceedings of the ASYMMETRICAL PLANETARY NEBULAE VI Conference. November 4-8, 2013, Riviera Maya, Mexico. published online / Internetpublication.
  • Reitberger, K.; Werner, M.; Reimer, O.; Egberts, K.; Takahashi, H.; 2012, Gamma-ray follow-up studies on eta Carinae, In: Aharonian, F.A.; Hofmann, W.; Rieger, F.M.; High energy gamma-ray astronomy: 5th International Meeting on High Energy Gamma-Ray Astronomy. July 9-13, 2012, Heidelberg, Germany. College Park, MD: American Institute of Physics (AIP) 414-417, DOI: 10.1063/1.4772285.
  • Reitberger, K.; Reimer, O.; Reimer, A.; Werner, M.; Egberts, K.; Takahashi, H.; 2012, Gamma-ray follow-up studies on η Carinae, Astronomy & Astrophysics 544, DOI: 10.1051/0004-6361/201219249.
  • Reitberger, K.; Breisky, A.; 2013, Cosmic Rays! The Life of Victor F. Hess, 2012, innsbruck university press (translated by Arthur Breisky).


Dominik Steinhauser, MSc
Current Affiliation: Institute for Astro- and Particle Physics
Reserach area(s): Theoretical Astrophysics, Galaxy evolution simulations

Application group: Univ.-Prof. Dr. Sabine Schindler

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Thesis:  Simulations of Galaxy-Cluster Interactions

Thesis abstract:
Observations have shown that galaxy evolution is highly dependent on environment. In denser regions of the universe, like galaxy groups and clusters, more elliptical and S0 galaxies can be found. Unlike spiral galaxies, those galaxies have a much lower star formation rate.
One possible mechanism in quenching the star formation rate of galaxies during their infall into the cluster center is ram-pressure stripping. Using numerical simulations, we want to study the phenomenon ram-pressure stripping and its implications on the evolution of spiral galaxies.

Cooperations within DK CIM:

  • Klaus Kofler, Computer Science
  • Markus Haider, Astrophysics
  • Harald Höller, Astrophysics
  • Christian Knapp, Complex Systems

External cooperations:

  • Prof. Volker Springel, Heidelberg Institute for Theoretical Studies, Germany (Theoretical Astrophysics)
  • Prof. Paola Merluzzi, INAF - Osservatorio Astronomico di Capadimonte Napoli, Italy (Astrophysics)

Selected publications:

  • Schiffner, D.; Ritter, M.; Steinhauser, D.; Benger, W., 2014, Using Curvilinear Grids to Redistribute Cluster Cells for Large Point Clouds, In: Obaid, M.; Sjölie, D.; Sintorn, E.; Fjeld, M.; Proceedings of SIGRAD 2014 - Visual Computing. June 12-13, 2014 Göteborg, Sweden. Linköping: Linköping University Electronic Press (= Linköping Electronic Conference Proceedings, 106), ISBN 978-91-7519-212-3, 9-16.
  • Kofler, K.; Steinhauser, D.; Biagio, C.; Grasso, I.; Schindler, S.; Fahringer, T.; 2014, Kd-tree Based N-Body Simulations with Volume-Mass Heuristic on the GPU, The 15th IEEE International Workshop on Parallel and Distributed Scientific and Engineering Computing (PDSEC 2014), May 23, 2014, USA, DOI: 10.1109/IPDPSW.2014.141.
  • Merluzzi, P.; Busarello, G.; Dopita, M. A.; Haines, C. P.; Steinhauser, D.; Mercurio, A.; Rifatto, A.; Smith, R. J.; Schindler, S.; 2013,: ACCESS - V. Dissecting ram-pressure stripping through integral-field spectroscopy and multiband imaging, Monthly Notices of the Royal Astronomical Society 429/2, 1747-1773, DOI: 10.1093/mnras/sts466.
  • Benger, W.; Haider, M.; Stöckl, J.; Cosenza, B.; Ritter, M.; Steinhauser, D.; Höller, H.; 2012, Visualization Methods for Numerical Astrophysics, In: Kucuk, I.; Astrophysics. Rijeka: InTech 259-286, DOI: 10.5772/32203.
  • Steinhauser, D.; Haider, M.; Kapferer, W.; Schindler, S.; 2012, Galaxies undergoing ram-pressure stripping: the influence of the bulge on morphology and star formation rate. A&A 544 A54, DOI: 10.1051/0004-6361/201118311.


styliani_tsantakiDipl.-Ing. Stella Tsantaki, Ph.D.
Current Affiliation: Institute of Basic Sciences in Engineering Sciences
Reserach area(s): Earthquake engineering, performance based design, collapse capacity,
aleatory and epistemic uncertainty, P-Delta effect
Applications group: Univ.-Prof. Dr. Christoph Adam

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Thesis:  A contribution to the assessment of the seismic collapse capacity of basic structures vulnerable to the destabilizing effect of gravity loads

Thesis abstract:
The collapse capacity of highly inelastic non-degrading single and multi-degree-of freedom systems vulnerable to the P-Delta effect was investigated. The aleatory and epistemic uncertainty of collapse capacity spectra were quantified. A use of an efficient intensity measure led to the reduction of record-to-record variability to 0.2-0.25 instead of 0.4-0.45 for the single degree-of-freedom systems.

Cooperations within DK CIM:

  • Michael Oberguggenberger, Engineering Mathematics
  • Lukas Wurzer, Engineering Mathematics

External cooperations:

  • Prof. F. L. Ibarra, University of Utah, USA (Civil engineering)

Selected publications:

  • Tsantaki, S.; Wurzer, L.; Jäger, C.; Adam, C.; Oberguggenberger, M.; 2012, Refined collapse capacity spectra for predicting seismic collapse of structures vulnerable to the P-delta effect, In: Eberhardsteiner, J. et al. (eds.): Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), September 10-14, 2012, Vienna, AT, CD-ROM paper, 17, ISBN: 978-3-9502481-9-7
  • Adam, C.; Ibarra, L.F.; Tsantaki, S.; 2014, Uncertainty of the collapse capacity of earthquake excited simple structures vulnerable to the P-delta effect, In: Ecker, H.; Steindl, A.; Jakubek, S.; Proceedings of the 8th European Nonlinear Dynamics Conference (ENOC 2014), July 6-11 2014, Vienna, AT, Technische Universität Wien, ISBN: 978-3-200-03433-4, 257.
  • Adam, C.; Tsantaki, S.; Ibarra, L.F.; Kampenhuber, D.; 2014, Record-to-record variability of the collapse capacity of multi-story frame structures vulnerable to P-delta, In: Second European Conference on Earthquake Engineering and Seismology (2ECEES), Istanbul: Özyeğin University, ISBN: 978-605-62703-6-9, online.
  • Tsantaki, S.; Adam, C.; 2013, Collapse capacity spectra based on an improved intensity measure, In: Papadrakakis, M.; Papadopoulos, V.; Plevris, V. (eds): Proceedings of 4th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2013), Kos Island, Greece, June 12–14, 2013. Barcelona: European Community on Computational Methods in Applied Sciences (ECCOMAS), 1382, 14.
  • Tsantaki, S.; Ibarra, L.F.; Adam, C.; 2013, Effect of modelling uncertainty on the seismic collapse capacity of simple systems vulnerable to the P-delta effect. In: Adam, C.; Heuer, R.; Lenhardt, W.; Schranz, C. (eds): Proceedings Vienna Congress on Recent Advances in Earthquake Engineering and Structural Dynamics 2013 (VEESD 2013), August 29-30, 2013, Wien, Österreich. Wien: Österreichische Gesellschaft für Erdbebeningenieurwesen (OGE).


untereggerDipl.-Ing. David Unteregger, Ph.D.
Current Affiliation: Brenner Base Tunnel SE - BBT SE
Reserach area(s): Mechanics of Solid Materials

Application group: Univ.-Prof. Dr. Günter Hofstetter

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Thesis:  Advanced constitutive modeling of intact rock and rock mass

Thesis abstract:
A constitutive model for rock mass is introduced. The aim of the development are reliable simulations of the excavation of deep tunnels. The proposed model is based on the combination of a damage-plasticity model for intact rock and semi-empirical relations between intact rock and rock mass properties.

External cooperations:

  • Brenner Basistunnel BBT-SE, Austria - Italy

Selected publications:

  • Unteregger, D.; Hofstetter, G.; Haltmeier, M.; Ostermann, A.; 2014, Parameter identification for an advanced model for intact rock, Proc. Numerical Methods in Geotechnical Engineering, Rotterdam, Leiden u.a.: Balkema (CRC Press), Bd. 1, 215-220, DOI: 10.1201/b17017-40.
  • Unteregger, D.; Hofstetter, G.; Burger, U.; Reinhold, C.; Rieder, A.; Weifner, T.; 2014, Constitutive modeling of rock mass in deep tunnels, BrennerCongress 2014, February 20-21, 2014, Innsbruck, Austria, Ernst & Sohn Special Feber 2014, 189-194. 
  • Unteregger, D.; Hofstetter, G.; 2014, Modellierung des Gebirgsverhaltens für die numerische Simulation des Vortriebs tiefliegender Tunnel, In: Bletzinger, K.U.; Baustatik-Baupraxis 12, February 24-25, 2014, Technische Universität München, Germany, 2014, 443-450.
  • Unteregger, D.; Fuchs, B.; Hofstetter, G.; 2013, Damage plasticity model for intact rock, Euro:Tun 2013, 3rd International Conference on Computational Methods in Tunneling and Subsurface Engineering, April 17-19, 2013, Bochum, Germany.
  • Unteregger, D.; Hofstetter, G.; 2013, Damage plasticity model for intact rock, In: Proceedings of 47th US Rock Mechanics/Geomechanics Symposium, ARMA 2013, June 23-26, 2013, San Francisco, USA.


wernerMichael Werner, MSc Ph.D.
Current Affiliation:
Reserach area(s):
 Astroparticle Physics

Applications group: Univ.-Prof. Dr. Olaf Reimer

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Thesis:  Programming, Analysis and Optimization for High Performance Computing

Thesis abstract:
Understanding the propagation physics of Cosmic Rays in our Galaxy is essential in analyzing and interpreting data of Cosmic Ray experiments.  We employ a new propagation code, called PICARD, for deca-parsec resolution 3D simulations in order to study the propagation of Cosmic Rays in the Milky Way. We formulate novel Cosmic Ray propagations scenarios and, among other things, test the influence of non-axisymmetric source distributions. We develop new tools for data handling and analysis.

Cooperations within DK CIM:

  • Alexander Ostermann, Numerics
  • Philipp Gschwandtner, OpenMP optimization of GALPROP code

External cooperations:

  • Andrew Strong, Max-Planck-Institut für extraterrestrische Physik, Germany
  • FERMI-LAT Collaboration 

Selected publications:

  • Kissmann, R.; Werner, M.; Egberts, K.; Reimer, O.; Egberts, K.; Csomos, P.; Ostermann, A.; 2012, Physics and parameters in galactic CR transport models, In: Aharonian, F.A., Hofmann, W., Rieger, F.M., High energy gamma-ray astronomy: 5th International Meeting on High Energy Gamma-Ray Astronomy, July 09-13, 2012, Heidelberg, DE. College Park, MD: American Institute of Physics (AIP), 450-453. DOI: 10.1063/1.4772294.
  • Reitberger, K.; Werner, M.; Reimer, O.; Egberts, K.; Takahashi, H.; 2012, Gamma-ray follow-up studies on eta Carinae, In: Aharonian, F.A.; Hofmann, W.; Rieger, F.M.; High energy gamma-ray astronomy: 5th International Meeting on High Energy Gamma-Ray Astronomy, July 9-13, 2012, Heidelberg, Germany. College Park, MD: American Institute of Physics (AIP) 414-417, DOI: 10.1063/1.4772285.
  • Reitberger, K.; Reimer, O.; Reimer, A.; Werner, M.; Egberts, K.; Takahashi, H.; 2012, Gamma-ray follow-up studies on η Carinae, Astronomy & Astrophysics 544, DOI: 10.1051/0004-6361/201219249. 
  • Werner, M.; Kissmann, R.; Strong, A.W.; Reimer, O., 2013, A new 3D transport and radiation code for galactic cosmic rays, Proceedings of the 33rd International Cosmic Ray Conference (ICRC 2013), Rio de Janeiro 2013. USA: e-proceedigs: arXiv: 1308.2829.
  • Werner, M.; Reimer, O.; Reimer, A.; Egberts, K.; 2013, Fermi LAT upper limits on gamma-ray emission from colliding wind binaries, Astronomy and Astrophysics 555, A102, DOI: 10.1051/0004-6361/201220502.


undefinedDipl.-Phys. Matthias Wiesenberger, Ph.D.
Current Affiliation: Institute of Ion Physics and Applied Physics
Reserach area(s): Plasma Physics, Numerics

Applications group: Assoc. Prof. Dr. Alexander Kendl 

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Thesis: Gyrofluid computations of Filament Dynamics in tokamak scrape-off layers

Thesis abstract:
We investigate field aligned density perturbations in the tokamak scrape-off-layer of magnetically confined plasmas. To this end numerical simulations are performed. We employ discontinuous Galerkin methods which are high order accurate and easily parallelizable. A GPU version of the code was written. In the near future we want to extend the code to also treat turbulence in the near SOL and edge plasma.

Cooperations within DK CIM:

  • Lukas Einkemmer, discontinous Galerkin methods

External cooperations:

  • Dr. Jens Madsen, DTU Risoe, Denmark (Gyrodluid simulations)

Selected publications:

  • Held, M.; Wiesenberger, M.; Kendl, A.; 2015, Full-f gyrofluid egde turbulence computations in 3-d toroidal and 2-d slab geometry, 42nd EPS Conference on Plasma Physics, June 22-26, 2015, Lisbon, PT.
  • Einkemmer, L.; Wiesenberger, M.; 2014, A conservative discontinuous Galerkin scheme for the 2D incompressible Navier-Stokes equations, Computer Physics Communications 2014, Vol. 185, Issue 11, 2865–2873, DOI: 10.1016/j.cpc.2014.07.007.
  • Wiesenberger, M.; Madsen, J.; Kendl, A.; 2014, Radial convection of finite ion temperature, high amplitude plasma blobs, Physics of Plasmas, DOI: 10.1063/1.4894220.
  • Wiesenberger, M.; Kendl, A.; 2013, Gyrofluid computation of impurity convection by interchange blobs in tokamak edge plasmas, Proceedings of the 40th European Physical Society Conference for Plasma Physics, Espoo, Finland, July 01-05, 2013.
  • Wiesenberger, M.; Kendl, A.; 2011, Gyrokinetic computation of waves and turbulence in the intra-cluster medium, 478th Hereaus Seminar, Fusion and Astrophysical Plasmas, Bad Honnef, Germany, April 18-20, 2011.


Mag. Lukas Wurzer, Ph.D.
 Current Affiliation: LUK GmbH & Co KG
Reserach area(s):
 Engineering Mathematics

Methods group: Univ.-Prof. Dr. Michael Oberguggenberger

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Thesis: Stochastic Differential Equations, Random Sets and Distributions

Thesis abstract:
We consider Stochastic Partial Differential Equations (SPDEs) with unceartain parameters. The inhomogenity of the SPDEs is modelled as a white noise in space and time and the parameters are random sets. We investigate measurability conditions for the solutions, which are ramdom sets on distribution spaces.

Cooperations within DK CIM:

  • Stella Tsantaki, Earthquake Engineering

External cooperations:

  • Prof. Francesco Russo, ENSTA Paristech, France (Stochastics, Financial Mathematics)

Selected publications:

  • Tsantaki, S.; Wurzer, L.; Jäger, C.; Adam, C.; Oberguggenberger, M.; 2012, Refined collapse capacity spectra for predicting seismic collapse of structures vulnerable to the P-delta effect, In: Eberhardsteiner, J. et al. (eds.): Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), September 10-14, 2012, Vienna, AT, CD-ROM paper, 17, ISBN: 978-3-9502481-9-7.
  • Grübl, G.; Wurzer, L.; 2011, Lower Bound for the Mean Square Distance between Classical and Quantum Spin Correlations, Journal of Physics A: Mathematical and Theoretical 44/9, DOI: 10.1088/1751-8113/44/9/095307.


Vu Thai Luan, MSc PhD
Current Affiliation: University of California, Merced (USA)
Reserach area(s): Numerical analysis and scientific computing, in particular:
Time integration of partial differential equations

Methods group: Univ.-Prof. Dr. Alexander Ostermann
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Thesis: Higher-order Exponential Integrators

Thesis abstract:
In this thesis, we are concerned with the construction and analysis of high-order exponential integrators for the time discretization of large systems of stiff differential equations. The construction of exponential integrators heavily relies on the knowledge of the order conditions, which are available in the literature up to order four. We introduce a novel approach for deriving the stiff order conditions for two popular classes of exponential integrators, namely exponential Runge-Kutta and exponential Rosenbrock methods. Based on this new approach, we obtain stiff order conditions for such exponential methods of order up to five. These conditions allow us to construct methods of order five. As examples, we present fifth-order exponential Runge-Kutta and exponential Rosenbrock methods. For particular problems the new order conditions can be simplified. It is then even possible to construct an exponential Rosenbrock method of order five with three stages only. The error analysis is performed in an abstract Banach space framework of strongly continuous (or analytic) semigroups. Convergence results are proven independently of the stiffness of the problem.  Moreover, we investigate an alternative approach for deriving the stiff order conditions by extending the well-known concept of B-series to exponential integrators. More precisely, we derive a stiff B-series theory based on the variation-of-constants formula. With the help of this theory, the stiff order conditions for such exponential methods of arbitrary order can be obtained in a simple way from a set of recursively defined trees.  The implementation of new integrators and the comparison with existing methods are carried out by using MATLAB. In particular, numerical examples for semilinear parabolic PDEs in one and two space dimensions are given to demonstrate the efficiency of the new integrators.

Cooperations within DK CIM: 

  • Prof. Alexander Ostermann, Numerical analysis
  • Marcel Ritter, Civil Engineering

External cooperations:

  • Prof. Marlis Hochbruck, Department of Mathematics, Karslruhe Institute of Technology (Germany)
  • Abdullah Demirel, MSc., Department of Mathematics, Karlsruhe Institute of Technology (Germany)

Selected publications:

  • Luan, V.T.; Ostermann A.; 2012, Stiff order conditions for exponential Runge-Kutta methods of order five, Proceedings of the Fifth International Conference on High Performance Scientific Computing, 2012, Hanoi, Vietnam; DOI: 10.1007/978-3-319-09063-4_11.
  • Luan, V.,T.; Ostermann, A.; 2014, Explicit exponential Runge-Kutta methods of high order for parabolic problems, J. Comput. Appl. Math. 256, 168-179, DOI: 10.1016/j.cam.2013.07.027; reprinted in: J. Comput. Appl. Math. 262, 361-372, DOI: 10.1016/j.cam.2014.01.001.
  • Luan, V.T.; Ostermann, A.; 2014, Exponential Rosenbrock methods of order five - construction, analysis and numerical comparisons, J. Comput. Appl. Math. 255, 417-431, DOI: 10.1016/j.cam.2013.04.041.
  • Luan, V.T.; Ostermann, A.; 2014, Stiff order conditions for exponential Runge-Kutta methods of order five, In: Modeling, Simulation and Optimization of Complex Processes - HPSC 2012 (H.G. Bock et al., eds.)Springer International Publishing, 133-143, DOI 10.1007/978-3-319-09063-4_11.