Contact
Universitätsstraße 32
70569 Stuttgart
Deutschland
Room: 02.324
Office Hours
Consultation by appointment
Subject
- Model order reduction
- Data-driven surrogate models
- Delay differential-algebraic equations
- Port-Hamiltonian systems
- Digital Twins and Physics-informed machine learning
2023
- V. Mehrmann and B. Unger, “Control of port-Hamiltonian differential-algebraic systems and applications,” Acta Numerica, vol. 32, pp. 395–515, 2023, doi: 10.1017/S0962492922000083.
- T. Holicki, J. Nicodemus, P. Schwerdtner, and B. Unger, “Energy matching in reduced passive and port-Hamiltonian systems,” 2023.
- R. Morandin, J. Nicodemus, and B. Unger, “Port-Hamiltonian Dynamic Mode Decomposition,” SIAM Journal on Scientific Computing, vol. 45, Art. no. 4, Jul. 2023, doi: 10.1137/22m149329x.
2022
- V. Mehrmann and B. Unger, “Control of port-Hamiltonian differential-algebraic systems and applications,” ArXiv e-print 2201.06590, 2022, [Online]. Available: http://arxiv.org/abs/2201.06590
- F. Black, P. Schulze, and B. Unger, “Modal Decomposition of Flow Data via Gradient-Based Transport Optimization,” in Active Flow and Combustion Control 2021, R. King and D. Peitsch, Eds., Cham: Springer International Publishing, 2022, pp. 203–224. doi: 10.1007/978-3-030-90727-3_13.
- T. Breiten, D. Hinsen, and B. Unger, “Towards a modeling class for port-Hamiltonian systems with time-delay,” 2022. doi: 10.48550/arXiv.2211.10687.
- D. Frank, D. A. Latif, M. Muehlebach, B. Unger, and S. Staab, “Robust Recurrent Neural Network to Identify Ship Motion in Open Water with Performance Guarantees,” Publication, 2022. doi: 10.48550/arXiv.2212.05781.
- B. Hillebrecht and B. Unger, “Certified machine learning: Rigorous a posteriori error bounds for PDE defined PINNs,” 2022.
- T. Breiten and B. Unger, “Passivity preserving model reduction via spectral factorization,” Automatica, vol. 142, p. 110368, Aug. 2022, doi: 10.1016/j.automatica.2022.110368.
- J. Heiland and B. Unger, “Identification of Linear Time-Invariant Systems with Dynamic Mode Decomposition,” Mathematics, vol. 10, Art. no. 3, 2022, doi: 10.3390/math10030418.
- B. Hillebrecht and B. Unger, “Certified machine learning: A posteriori error estimation for physics-informed neural networks,” ArXiv e-print 2203.17055, 2022, [Online]. Available: http://arxiv.org/abs/2203.17055
- R. Altmann, R. Maier, and B. Unger, “Semi-explicit integration of second order for weakly coupled poroelasticity,” ArXiv e-print 2203.16664, 2022, [Online]. Available: http://arxiv.org/abs/2203.16664
- R. Morandin, J. Nicodemus, and B. Unger, “Port-Hamiltonian Dynamic Mode Decomposition,” ArXiv e-print 2204.13474, 2022, doi: 10.48550/arXiv.2204.13474.
- B. Hillebrecht and B. Unger, “Certified machine learning: A posteriori error estimation for physics-informed neural networks,” in 2022 International Joint Conference on Neural Networks (IJCNN), IEEE, Jul. 2022, pp. 1–8. doi: 10.1109/ijcnn55064.2022.9892569.
- J. Nicodemus, J. Kneifl, J. Fehr, and B. Unger, “Physics-informed Neural Networks-based Model Predictive Control for Multi-link Manipulators,” IFAC-PapersOnLine, vol. 55, Art. no. 20, 2022, doi: 10.1016/j.ifacol.2022.09.117.
2021
- R. Altmann, R. Maier, and B. Unger, “Semi-explicit discretization schemes for weakly coupled elliptic-parabolic problems,” Mathematics of Computation, vol. 90, Art. no. 329, 2021, doi: 10.1090/mcom/3608.
- F. Black, P. Schulze, and B. Unger, “Decomposition of flow data via gradient-based transport optimization,” ArXiv e-print 2107.03481, 2021, [Online]. Available: https://arxiv.org/abs/2107.03481
- I. Ahrens and B. Unger, “A simple success check for delay differential-algebraic equations,” in Proceedings in Applied Mathematics and Mechanics 2020, Wiley, 2021, p. e202000270. doi: 10.1002/pamm.202000270.
- F. Black, P. Schulze, and B. Unger, “Efficient Wildland Fire Simulation via Nonlinear Model Order Reduction,” Fluids, vol. 6, Art. no. 8, 2021, doi: 10.3390/fluids6080280.
- I. V. Gosea, S. Gugercin, and B. Unger, “Parametric model reduction via rational interpolation along parameters,” in 2021 60th IEEE Conference on Decision and Control (CDC), 2021, pp. 6895–6900. doi: 10.1109/CDC45484.2021.9682841.
- I. V. Gosea, S. Gugercin, and B. Unger, “Parametric model reduction via rational interpolation along parameters,” ArXiv e-print 2104.01016, 2021, [Online]. Available: https://arxiv.org/abs/2104.01016
- F. Black, P. Schulze, and B. Unger, “Model order reduction with dynamically transformed modes for the wave equation,” in Proceedings in Applied Mathematics and Mechanics 2020, Wiley, 2021, p. e202000321. doi: 10.1002/pamm.202000321.
- R. Altmann, V. Mehrmann, and B. Unger, “Port-Hamiltonian formulations of poroelastic network models,” Mathematical and Computer Modelling of Dynamical Systems, vol. 27, Art. no. 1, 2021, doi: 10.1080/13873954.2021.1975137.
- J. Heiland and B. Unger, “Identification of linear time-invariant systems with Dynamic Mode Decomposition,” ArXiv e-print 2109.06765, 2021, [Online]. Available: https://arxiv.org/abs/2109.06765
- F. Black, P. Schulze, and B. Unger, “Efficient Wildland Fire Simulation via Nonlinear Model Order Reduction,” ArXiv e-print 2106.11381, 2021, [Online]. Available: https://arxiv.org/abs/2106.11381
- T. Breiten and B. Unger, “Passivity preserving model reduction via spectral factorization,” ArXiv e-print 2103.13194, 2021, [Online]. Available: https://arxiv.org/abs/2103.13194
- J. Nicodemus, J. Kneifl, J. Fehr, and B. Unger, “Physics-informed Neural Networks-based Model Predictive Control for Multi-link Manipulators,” ArXiv e-print 2109.10793, 2021, [Online]. Available: https://arxiv.org/abs/2109.10793
- S. Trenn and B. Unger, “Unimodular transformations for DAE initial trajectory problems,” in Proceedings in Applied Mathematics and Mechanics 2020, Wiley, 2021, p. e202000322. doi: 10.1002/pamm.202000322.
- R. Altmann, R. Maier, and B. Unger, “A semi-explicit integration scheme for weakly-coupled poroelasticity with nonlinear permeability,” in Proceedings in Applied Mathematics and Mechanics 2020, Wiley, 2021, p. e202000061. doi: 10.1002/pamm.202000061.
2020
- I. Ahrens and B. Unger, “The Pantelides algorithm for delay differential-algebraic equations,” Transactions of Mathematics and Its Application, vol. 4, Art. no. 1, 2020, doi: 10.1093/imatrm/tnaa003.
- R. Altmann, R. Maier, and B. Unger, “Semi-explicit discretization schemes for weakly coupled elliptic-parabolic problems,” Mathematics of Computation, p. 1, Oct. 2020, doi: 10.1090/mcom/3608.
- R. Altmann, V. Mehrmann, and B. Unger, “Port-Hamiltonian formulations of poroelastic network models,” ArXiv e-print 2012.01949, Dec. 2020, [Online]. Available: https://arxiv.org/abs/2012.01949
- F. Black, P. Schulze, and B. Unger, “Projection-based model reduction with dynamically transformed modes,” ESAIM: Mathematical Modelling and Numerical Analysis, vol. 54, Art. no. 6, Oct. 2020, doi: 10.1051/m2an/2020046.
- B. Unger, “Delay differential-algebraic equations in real-time dynamic substructuring,” ArXiv e-print 2003.10195, Mar. 2020, [Online]. Available: https://arxiv.org/abs/2003.10195
2019
- S. Trenn and B. Unger, “Delay regularity of differential-algebraic equations,” in 2019 IEEE 58th Conference on Decision and Control (CDC), Dec. 2019, pp. 989–994. doi: 10.1109/CDC40024.2019.9030146.
- E. Fosong, P. Schulze, and B. Unger, “From Time-Domain Data to Low-Dimensional Structured Models,” ArXiv e-print 1902.05112, Feb. 2019, [Online]. Available: https://arxiv.org/abs/1902.05112
- B. Unger and S. Gugercin, “Kolmogorov n-widths for linear dynamical systems,” Advances in Computational Mathematics, vol. 45, Art. no. 5, Dec. 2019, doi: 10.1007/s10444-019-09701-0.
- D. Kern, M. Bartelt, and B. Unger, “How to write an article for GAMMAS and a longer title,” GAMM Archive for Students, vol. 1, Art. no. 1, Feb. 2019, doi: 10.14464/gammas.v1i1.417.
2018
- P. Schulze, B. Unger, Christopher. Beattie, and S. Gugercin, “Data-driven Structured Realization,” Linear Algebra and its Applications, vol. 537, pp. 250–286, 2018, doi: 10.1016/j.laa.2017.09.030.
- P. Schulze and B. Unger, “Model reduction for linear systems with low-rank switching.,” SIAM J. Control and Optimization, vol. 56, Art. no. 6, 2018, doi: 10.1137/18M1167887.
- B. Unger, “Discontinuity Propagation in Delay Differential-Algebraic Equations,” The Electronic Journal of Linear Algebra, vol. 34, pp. 582–601, Feb. 2018, doi: 10.13001/1081-3810.3759.
2016
- P. Schulze and B. Unger, “Data-driven interpolation of dynamical systems with delay.,” Systems Control Lett., vol. 97, pp. 125–131, 2016, doi: 10.1016/j.sysconle.2016.09.007.
2015
- V. Mehrmann and B. Unger, “Index preserving polynomial representation of nonlinear differential-algebraic systems,” Institut für Mathematik, TU Berlin, Str. des 17. Juni 136, D-10623 Berlin, FRG, Preprint 2––2015, 2015. [Online]. Available: http://www3.math.tu-berlin.de/cgi-bin/IfM/show_abstract.cgi?Report-02-2015.rdf.html
2013
- B. Unger, “Impact of Discretization Techniques on Nonlinear Model Reduction and Analysis of the Structure of the POD Basis,” Master’s Thesis, Virginia Polytechnic and State University, Blacksburg, Virginia, USA, 2013. [Online]. Available: https://vtechworks.lib.vt.edu/handle/10919/24197
- Artificial intelligence meets molecular dynamics: certified machine learning for resolution transformation
Together with Dr. K. Pluhackova, Aug. 2021 – Dez. 2023 - Decoupling integration schemes of higher order for poroelastic networks
Together with Dr. habil. R. Altmann, Oct. 2021 – Sept. 2024 - Data-Integrated Low-Dimensional Surrogate Models with Guarantees
June 2021 – Oct. 2024
Invited Talks
- Model reduction for transport phenomena via state-dependent projections
MOR Seminar (online), Universität Stuttgart, Apr. 2021. - Co-Design via port-Hamiltonian systems: advantages, challenges, and perspectives
Workshop of the GAMM activity group on dynamics and control theory (online), Feb. 2021. - Structure-Preserving Model-Order Reduction for Port-Hamiltonian Systems
Oberseminar Numerical Optimization (online), Universität Konstanz, Jan. 2021. - Kolmogorov n-widths and Hankel normapproximation
Applied Numerical Analysis Seminar (Virginia Tech), Blacksburg, USA, Feb. 2017.
Minisymposium Talks
- Model reduction for mixed data and first-principle models
Mechanistic Machine Learning and Digital Twins for Computational Science, Engineering & Technology, San Diego, USA, Sept. 2021. - The Digital Twin Philosophy for Additive Manufacturing
SIAM Conference on Computational Science and Engineering, online, Mar. 2021. - Nonlinear Galerkin model reduction for transport-dominated problems
DMV Jahrestagung 2020, Chemnitz, Deutschland, Sept. 2020. - From Data to Structured Reduced-orderModels
SIAM Conference on Computational Science and Engineering, Spokane, USA, Feb. 2019. - Well-posedness and numerical solution of nonlinear delay differential-algebraic equations
International Conference on Scientific Computation and Differential Equations, Bath, UK, Sept. 2017. - Model Reduction, Transport Problems, and Structure
SIAM Conference on Computational Science and Engineering, Atlanta, USA, Feb. 2017. - Structured surrogate models of complex dynamical systems based on input/output data
7th European Congress ofMathematics (7ECM), Berlin, Germany, Juli 2016. - Structured input/output realization of dynamical systems
20th Conference of the International Linear Algebra Society, Leuven, Belgium, July 2016.
Selected other talks and poster
- Passivity preserving MOR via spectral factorization
GAMM-Workshop 2021 -- Sion Digital online), Mar. 2021. - Asymptotic stability of neutral delay equations via semi-explicit time-integration
GAMM Jahrestagung (online), Kassel, Germany, Mar. 2021. - Delay regularity of differential-algebraic equations
58th IEEE Conference on Decision and Control, Nizza, France, Dec. 2019. - Model reduction for switched systems with low-rank switching (Poster)
IUTAM Symposium on Model Order Reduction of Coupled Systems, Stuttgart, Germany, May 2018. - Delay Differential-Algebraic Equations: Primary Discontinuities and Regularization
Analysis andNumerical Approximation ofConstrained Systems, Sion, Switzerland, April 2018. - Kolmogorov n-widths and optimal Hankel norm approximation
GAMM Annual Meeting, Munich, Germany, March 2018 - What is a well-posed delay differential-algebraic equation?
Workshop on Control of Self-OrganizingNonlinear Systems Lutherstadt Wittenberg, Germany, Aug. 2017. - Nonintrusive Realization Theory for Structured Problems
KoMSO Challenge Workshop Reduced-Order Modeling for Simulation and Optimization, Renningen, Germany, Nov. 2016.
- Workshop: Trends on dissipativity in systems and control, Brig, Switzerland, May 2022 (together with T. Faulwasser and M. Voigt)
- Conference session co-chair: GAMM Jahrestagung, Aachen, Aug. 2022, Session S20 Dynamics and Control (together with S. Grundel)
- Conference: Energy-Based Modeling, Simulation, and Control of Complex Constrained Multiphysical Systems, CIRM, Luminy, France, April 2022 (together with P. Kotyzka, Y. Le Gorrec, B.Maschke, D.Matignon, J. Scherpen)
- Minisymposium: Recent advances in model reduction and surrogate modeling,
MATHMOD 2022, Vienna, Austria, February 2022 (together with T. Breiten, J. Fehr, S. Rave, J. Saak) - Minisymposium: Model order reduction and approximation of coupled systems,
DMV Jahrestagung 2021 (online), Sept. 2021 (together with B. Lilljegren-Sailer) - Minisymposium: GAMM Juniors Poster Session,
GAMM Jahrestagung 2021 (online), Mar. 2021 - Minisymposium: Mathematical Aspects of the Digital Twin Modeling Paradigm, SIAM CSE 20201, virtual conference, March 2021 (together with P. Bürkner)
- Minisymposium:NumericalMethods for port-Hamiltonian systems,DMVJahrestagung 2020, Chemnitz, Germany, Sept. 2020 (together with R. Altmann)
- Conference: Meeting of the European SIAM and GAMM student chapters, Berlin, Germany, Sept. 2018 (together with D. Bankmann)
- Young AcademicsMeetMentors (YAMM) Lunch, GAMMJahrestagung 2018,Munich, Germany, March 2018 (together with L. Pauli)
- Minisymposium: Modeling and simulation of transport-dominated phenomena, 7ECM, July 2016, Berlin, Germany (together with C. Beattie, S. Gugercin, P. Schulze)
- Conference: Energy Based Modeling, Simulation, and Control of Complex Physical Systems, April 2016, Berlin, Germany (together with V.Mehrmann, A.Miedlar, P. Schulze)
- Summer school: Energy Based Modeling, Simulation, and Control of Complex Physical Systems, April 2016, Berlin, Germany (together with V.Mehrmann, A.Miedlar, P. Schulze)
- Minisymposium: Simulation and control of delay differential-algebraic equations, SciCADE 2015, Sept. 2015, Potsdam, Germany (together with V.Mehrmann)
- 16th IFACWorkshop on Time Delay Systems (TDS 2021)
Associate Editor - GAMM Archive for Students
Editor from 2018-2019, Founding Editor
- Aug. 2019, Centre International De Rencontres Mathématiques, Lumini, France
Research in Pairsmit Dr. R. Altmann and Dr. R. Maier - June 2018, University of Groningen, Groningen, Netherlands
Invited by Prof. Dr. S. Trenn - Feb. 2017, Virginia Tech in Blacksburg, Virginia, USA
Invited by Prof. Dr. S. Gugercin
Ph.D. students:
- Birgit Hillebrecht, University of Stuttgart (since Nov. 2021)
- Jonas Nicodemus, University of Stuttgart (since July 2021)
- Abdullah Mujahid, Augsburg University and University of Stuttgart (since Nov. 2021)
- Christian Pfaendner, University of Stuttgart (since Oct. 2021)
Master theses:
- Abdullah Mujahid, Ruhr Universität Bochum
Master thesis (Oct. 2021): Monolithic and iterative discretizations of linear poroelasticity (together with P. Henning and R. Altmann) - Felix Black, Technische Universität Berlin
Master thesis (Jan. 2019): Model order reduction for transport phenomena (together with V. Mehrmann und P. Schulze) - Ines Ahrens, Technische Universität Berlin
Master thesis (Sept. 2018): A Structural Approach for Delay Differential-Algebraic Equations (together with V. Mehrmann) - Viola Paschke, Technische Universität Berlin
Master thesis (July 2016): Delayed Multibody Systems – Analysis and Numerical Solution (together with V. Mehrmann)
Scientific assistants, research projects, and interns:
- Zubair Asif, University of Stuttgart, scientific assistant (since Nov. 2021)
- Lisa Meisinger, University of Stuttgart, research project (since Oct. 2021)
- Ahsan Ayaz, University of Stuttgart, scientific assistant (since June 2021)
- Elliot Fosong, University of Cambridge, DAAD RISE internship (June-Sept. 2018)
- Oumayma Bentamer, ENSEEIHT Toulouse, internship (Juni - Sept. 2017)
- Yuliya Semibratova, University of Illinois at Urbana-Champaign, DAAD RISE internship (May - Aug. 2016)
- Ines Ahrens, Technische Universität Berlin, scientific assistant (Apr. 2016 - Sept. 2018)
- Viola Paschke, Technische Universität Berlin, scientific assistant (Feb. 2015 - Apr. 2016)
University of Stuttgart (independent teaching)
- Seminar: Control theory (summer term 2022)
- Seminar: Novel methods in simulation science (summer term 2022)
- Seminar: Advanved topics in simulation science (winter term 2021/22)
Technische Universität Berlin
- Assistent Lineare Algebra I für Mathematiker (Sommersemester 2020)
- Assistent Analysis II für Mathematiker (Sommersemester 2019)
- Assistent Analysis I für Mathematiker (Wintersemester 2018/2019)
- Assistent Analysis II für Ingenieure (Early Bird, Sommersemester 2018)
- Assistent Lineare Algebra II für Mathematiker (Wintersemester 2017/18)
- Assistent Lineare Algebra II für Mathematiker (Sommersemester 2017)
- Assistent Lineare Algebra I+II für Mathematiker (Wintersemester 2016/17)
- Tutor Analysis I für Ingenieure (Wintersemester 2015)
- Organisator Absolventen-Seminar NumerischeMathematik (Februar 2015 - Juli 2018)
Karlsruhe Institute for Technology
- Tutor NumerischeMathematik II (Sommersemester 2012)
- Tutor NumerischeMathematik I (Wintersemester 2011/12)
- Tutor VorkursMathematik (Wintersemester 2011/12)
- Tutor Einstieg in die Informatik und algorithmischeMathematik mit C++ (Sommersemester 2011)
- Tutor Einstieg in die Informatik und algorithmische Mathematik mit Java (Wintersemester 2010/11)
- Tutor Vorkurs Mathematik (Wintersemester 2010/11)
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