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Employment:

2022 –
Dept. of Applied Mathematics, Faculty of Electrical Engineering and Computer Science, VSB – Technical university of Ostrava, Junior Researcher
2018 –
Institute of Geonics of the Czech Academy of Sciences, PhD Student
2016 – 2018
IT4Innovations National Supercomputing Center, VSB – Technical University of Ostrava, Research Assistant
2015 – 2016
IT4Innovations National Supercomputing Center, VSB – Technical University of Ostrava, R&D Support Staff (part-time, 50%)

Education:

2018 – 2024
VSB – Technical university of Ostrava, Faculty of Electrical Engineering and Computer Science
PhD in Computational and Applied Mathematics
Thesis: Improving Quadratic Programming Algorithms
Advisor: David Horák
2016 – 2018
VSB – Technical university of Ostrava, IT4Innovations National Supercomputing Center
MSc with honours in Computational Sciences
Thesis: Implementation of the Deflated Variants of the Conjugate Gradient Method
Advisor: David Horák
2013 – 2016
VSB – Technical university of Ostrava, Faculty of Electrical Engineering and Computer Science
BSc with honours in Computational Mathematics
Thesis: Parallelizations of TFETI–1 coarse problem
Advisor: David Horák

Research Stays and Summer Schools:

2022 (6 months)
Department of Computer Science, FAU, Erlangen-Nuremberg
research stay with Prof. Ulrich Rüde, interfacing PERMON and HyTeG, constrained Stokes flow
2021 (3 months)
School of Mathematics and EPCC, University of Edinburgh, Edinburgh
research stay with Prof. Jacek Gondzio, Interior point methods for contact problems
2019 (3 months)
Institute of Mathematics, TU Berlin, Berlin 2019
3 months research stay with Prof. Reinhard Nabben, developing deflation preconditioner (PCDEFLATION in PETSc)
2017 (2 weeks)
Argonne Training Program on Extreme-Scale Computing, St. Charles
2016 (2 weeks)
Effective HPC summer school by CSCS and USI, Lugano
talk “Energy consumption optimization of a TFETI solver”

Awards:

2019
Dean of Faculty of Electrical Engineering and Computer Science award for accomplishments in PhD studies
2019 - 2022
Department of Applied Mathematics award for the best PhD students
2018
2nd place in "Prof. Babuška Prize", student category
2016
1st place in "Prof. Babuška Prize", student category
2016
Department of Applied Mathematics award for the best BSc thesis
2016
2nd place in SVOČ competition in mathematics and computer science, category: applied mathematics - numerical analysis

List of Publications:

Stanislav Sysala, Michal Béreš, Simona Bérešová, Jaroslav Haslinger, Jakub Kružík, and Tomáš Luber. Convex optimization problems inspired by geotechnical stability analysis. SIAM Journal on Optimization, 35(3):1993--2016, 2025. [ bib | DOI ]

Petr Vodstrčil, Dalibor Lukáš, Zdeněk Dostál, Marie Sadowská, David Horák, Oldřich Vlach, Jiří Bouchala, and Jakub Kružík. On favorable bounds on the spectrum of discretized Steklov--Poincaré operator and applications to domain decomposition methods in 2d. Computers & Mathematics with Applications, 167:12–20, August 2024. [ bib | DOI ]

Jan Stebel, Jakub Kružík, David Horák, Jan Březina, and Michal Béreš. On the parallel solution of hydro-mechanical problems with fracture networks and contact conditions. Computers & Structures, 298:107339, July 2024. [ bib | DOI ]

Zdeněk Dostál, Marie Sadowská, David Horák, and Jakub Kružík. Hybrid TBETI domain decomposition for huge 2d scalar variational inequalities. International Journal for Numerical Methods in Engineering, 125(24):e7597, 2024. [ bib | DOI ]

David Hrbáč, Jakub Kružík, David Horák, and Jaroslav Kruis. Node renumbering strategies for efficient direct methods in selected problems of soil mechanics. In International Conference of Numerical Analysis and Applied Mathematics ICNAAM 2021. AIP Publishing, 2023. [ bib | DOI ]

David Horák, Jakub Kružík, Jaroslav Kruis, and Tomáš Koudelka. Slip condition in slope stability analysis solved by FETI method. In International Conference of Numerical Analysis and Applied Mathematics ICNAAM 2021. AIP Publishing, 2023. [ bib | DOI ]

Zdeněk Dostál, David Horák, Jakub Kružík, Tomáš Brzobohatý, and Oldřich Vlach. Highly scalable hybrid domain decomposition method for the solution of huge scalar variational inequalities. Numerical Algorithms, 91(2):773–801, April 2022. [ bib | DOI ]

Zdeněk Dostál, Tomáš Brzobohatý, David Horák, Jakub Kružík, and Oldřich Vlach. Scalable hybrid TFETI-DP methods for large boundary variational inequalities. In Susanne C. Brenner, Eric Chung, Axel Klawonn, Felix Kwok, Jinchao Xu, and Jun Zou, editors, Domain Decomposition Methods in Science and Engineering XXVI, pages 29--40, Cham, 2022. Springer International Publishing. [ bib | DOI ]

Owe Axelsson, Zhao-Zheng Liang, Jakub Kruzik, and David Horak. Inner product free iterative solution and elimination methods for linear systems of a three-by-three block matrix form. Journal of Computational and Applied Mathematics, 383:113117, February 2021. [ bib | DOI ]

Serena Crisci, Jakub Kružík, Marek Pecha, and David Horák. Comparison of active-set and gradient projection-based algorithms for box-constrained quadratic programming. Soft Computing, 24(23):17761--17770, October 2020. [ bib | DOI ]

Lukáš Pospíšil, Martin Čermák, David Horák, and Jakub Kružík. Non-monotone projected gradient method in linear elasticity contact problems with given friction. Sustainability, 12(20):8674, October 2020. [ bib | DOI ]

Jakub Kruzik, David Horak, Vaclav Hapla, and Martin Cermak. Comparison of selected FETI coarse space projector implementation strategies. Parallel Computing, 93:102608, May 2020. [ bib | DOI ]

J. Kružík, D. Horák, M. Čermák, L. Pospíšil, and M. Pecha. Active set expansion strategies in MPRGP algorithm. Advances in Engineering Software, 149, 2020. [ bib | DOI ]

Jakub Kružík. Implementation of the deflated variants of the conjugate gradient method. Master's thesis, VSB - Technical University of Ostrava, 2018. [ bib | http ]

Radim Blaheta, Tomáš Luber, and Jakub Kružík. Schur complement-Schwarz DD preconditioners for non-stationary Darcy flow problems. In Tomáš Kozubek, Martin Čermák, Petr Tichý, Radim Blaheta, Jakub Šístek, Dalibor Lukáš, and Jiří Jaroš, editors, High Performance Computing in Science and Engineering, pages 59--72, Cham, 2018. Springer International Publishing. [ bib | DOI ]

Jakub Kružík, Marek Pecha, Václav Hapla, David Horák, and Martin Čermák. Investigating convergence of linear SVM implemented in PermonSVM employing MPRGP algorithm. In Tomáš Kozubek, Martin Čermák, Petr Tichý, Radim Blaheta, Jakub Šístek, Dalibor Lukáš, and Jiří Jaroš, editors, High Performance Computing in Science and Engineering, pages 115--129, Cham, 2018. Springer International Publishing. [ bib | DOI ]

David Horak, Vaclav Hapla, Jakub Kruzik, Radim Sojka, Martin Cermak, Jiri Tomcala, Marek Pecha, and Zdenek Dostal. A note on massively parallel implementation of FETI for the solution of contact problems. Advances in Electrical and Electronic Engineering, 15(2), July 2017. [ bib | DOI ]

Martin Čermák, Václav Hapla, Jakub Kružík, Alexandros Markopoulos, and Alena Vašatová. Comparison of different FETI preconditioners for elastoplasticity. Computers & Mathematics with Applications, 74(1):96–109, July 2017. [ bib | DOI ]

Alena Vašatová, Jiří Tomčala, Radim Sojka, Marek Pecha, Jakub Kružík, David Horák, Václav Hapla, and Martin Čermák. Parallel strategies for solving the FETI coarse problem in the PERMON toolbox. Programs and Algorithms of Numerical Mathematics, pages 154--163, 2017. [ bib ]

D. Horak, Z. Dostal, V. Hapla, J. Kruzik, R. Sojka, and M. Cermak. Projector-less TFETI for contact problems: Preliminary results. In Proceedings of the Fifth International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering, PARENG 2017. Civil-Comp Press, 2017. [ bib | DOI ]

J. Kruzik and D. Horak. Wavelet based deflation of conjugate gradient method. In Proceedings of the Fifth International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering. Civil-Comp Press, Stirlingshire, UK, 2017. [ bib | DOI ]

Joseph Schuchart, Michael Gerndt, Per Gunnar Kjeldsberg, Michael Lysaght, David Horák, Lubomír Říha, Andreas Gocht, Mohammed Sourouri, Madhura Kumaraswamy, Anamika Chowdhury, Magnus Jahre, Kai Diethelm, Othman Bouizi, Umbreen Sabir Mian, Jakub Kružík, Radim Sojka, Martin Beseda, Venkatesh Kannan, Zakaria Bendifallah, Daniel Hackenberg, and Wolfgang E. Nagel. The READEX formalism for automatic tuning for energy efficiency. Computing, 99(8):727–745, January 2017. [ bib | DOI ]

Radim Sojka, Lubomir Riha, David Horak, Jakub Kruzik, Martin Beseda, and Martin Cermak. The energy consumption optimization of the BLAS routines. In AIP Conference Proceedings. AIP Publishing, 2017. [ bib | DOI ]

Jan Papuga, Radim Halama, Martin Fusek, Jaroslav Rojíček, František Fojtík, David Horák, Marek Pecha, Jiří Tomčala, Martin Čermák, Václav Hapla, Radim Sojka, and Jakub Kružík. Efficient lifetime estimation techniques for general multiaxial loading. In AIP Conference Proceedings. AIP Publishing, 2017. [ bib | DOI ]

David Horak, Lubomir Riha, Radim Sojka, Jakub Kruzik, Martin Beseda, Martin Cermak, and Joseph Schuchart. Energy consumption optimization of the total-FETI solver by changing the cpu frequency. In AIP Conference Proceedings. AIP Publishing, 2017. [ bib | DOI ]

David Horak, Lubomir Riha, Radim Sojka, Jakub Kruzik, and Martin Beseda. Energy consumption optimization of the Total-FETI solver and BLAS routines by changing the cpu frequency. In 2016 International Conference on High Performance Computing & Simulation (HPCS). IEEE, July 2016. [ bib | DOI ]

Petr Vodstrčil, Dalibor Lukáš, Zdeněk Dostál, Marie Sadowská, David Horák, Oldřich Vlach, Jiří Bouchala, and Jakub Kružík. On favorable bounds on the spectrum of discretized Steklov--Poincaré operator and applications to domain decomposition methods in 2d. Computers & Mathematics with Applications, 167:12–20, August 2024. [ bib | DOI ]