Dr. Jens Saak

Palitta, D.; Tomljanović, Z.; Nakić, I.; Saak, J.: Efficient Solution of Sequences of Parametrized Lyapunov Equations with Applications. Numerical Linear Algebra with Applications 32 (1), e2604 (2025)

Saak, J.; Werner, S. W. R.: Using LDL^T Factorizations in Newton's Method for Solving General Large-Scale Algebraic Riccati Equations. Electronic Transactions on Numerical Analysis 62, S. 95 - 118 (2024)

Benner, P.; Palitta, D.; Saak, J.: On an integrated Krylov-ADI Solver for Large-Scale Lyapunov Equations. Numerical Algorithms 92, S. 35 - 63 (2023)

Boege, T.; Fritze, R.; Görgen, C.; Hanselman, J.; Iglezakis, D.; Kastner, L.; Koprucki, T.; Krause, T.; Lehrenfeld, C.; Polla, S. et al.; Reidelbach, M.; Riedel, C.; Saak, J.; Schembera, B.; Tabelow, K.; Weber, M.: Research-Data Management Planning in the German Mathematical Community. EMS Magazine 130, S. 40 - 47 (2023)

Erxleben, T.; Duwe, K.; Saak, J.; Köhler, M.; Kuhn, M.: Green Storage: Parallel File Systems on ARM. International Journal on Advances in Software 15 (3-4), S. 200 - 210 (2022)

Hund, M.; Mitchell, T.; Mlinarić, P.; Saak, J.: Optimization-Based Parametric Model Order Reduction via H₂ ⊗ L₂ First-Order Necessary Conditions. SIAM Journal on Scientific Computing 44 (3), S. A1554 - A1578 (2022)

Vettermann, J.; Steinert, A.; Brecher, C.; Benner, P.; Saak, J.: Compact Thermo-Mechanical Models for the Fast Simulation of Machine Tools with Nonlinear Component Behavior. at-Automatisierungstechnik 70 (8), S. 692 - 704 (2022)

Fehr, J.; Himpe, C.; Rave, S.; Saak, J.: Sustainable Research Software Hand-Over. Journal of Open Research Software 9 (1), 5 (2021)

Vetterman, J.; Sauerzapf, S.; Naumann, A.; Beitelschmidt, M.; Herzig, R.; Benner, P.; Saak, J.: Model Order Reduction Methods for Coupled Machine Tool Models. MM Science Journal (Special Issue: ICTIMT2021), S. 4652 - 4659 (2021)

Benner, P.; Bujanović, Z.; Kürschner, P.; Saak, J.: A Numerical Comparison of Different Solvers for Large-Scale, Continuous-Time Algebraic Riccati Equations and LQR Problems. SIAM Journal on Scientific Computing 42 (2), S. A957 - A996 (2020)

Benner, P.; Heinkenschloss, M.; Saak, J.; Weichelt, H. K.: Efficient Solution of Large-Scale Algebraic Riccati Equations Associated with Index-2 DAEs via the Inexact Low-Rank Newton-ADI Method. Applied Numerical Mathematics 152, S. 338 - 354 (2020)

Benner, P.; Dufrechou, E.; Ezzatti, P.; Remón, A.; Saak, J.: A GPU-Aware Mixed-Precision Solver for Low-Rank Algebraic Riccati Equations. Concurrency and Computation: Practice and Experience 31 (6), e4462, 12 pages (2019)

Benner, P.; Herzog, R.; Lang, N.; Riedel, I.; Saak, J.: Comparison of Model Order Reduction Methods for Optimal Sensor Placement for Thermo-Elastic Models. Engineering Optimization 51 (3), S. 465 - 483 (2019)

Köhler, M.; Saak, J.: Frequency Scaling and Energy Efficiency regarding the Gauss-Jordan Elimination Scheme with Application to the Matrix-Sign-Function on OpenPOWER 8. Concurrency and Computation: Practice and Experience 31 (6), e4504, 16 pages (2019)

Saak, J.; Siebelts, D.; Werner, S. W. R.: A Comparison of Second-Order Model Order Reduction Methods for an Artificial Fishtail. at - Automatisierungstechnik 67 (8), S. 648 - 667 (2019)

Baran, B.; Benner, P.; Heiland, J.; Saak, J.: Optimal Control of a Stefan Problem Fully Coupled with Incompressible Navier-Stokes-Equations and Mesh Movement. Analele Stiintifice ale Universitatii Ovidius Constanta - Seria Matematica 26 (2), S. 11 - 40 (2018)

Benner, P.; Bujanović, Z.; Kürschner, P.; Saak, J.: RADI: a Low-Rank ADI-Type Algorithm for Large Scale Algebraic Riccati Equations. Numerische Mathematik 138 (2), S. 301 - 330 (2018)

Hund, M.; Saak, J.: A Connection between Time Domain Model Order Reduction and Moment Matching for LTI Systems. Mathematical and Computer Modelling of Dynamical Systems 24 (5), S. 455 - 484 (2018)

Anzt, H.; Chow, E.; Saak, J.; Dongarra, J.: Updating Incomplete Factorization Preconditioners for Model Order Reduction. Numerical Algorithms 73 (3), S. 611 - 630 (2016)

Benner, P.; Heinkenschloss, M.; Saak, J.; Weichelt, H. K.: An Inexact Low-Rank Newton-ADI Method for Large-Scale Algebraic Riccati Equations. Applied Numerical Mathematics 108, S. 125 - 142 (2016)

Benner, P.; Kürschner, P.; Saak, J.: Low-Rank Newton-ADI Methods for Large Nonsymmetric Algebraic Riccati Equations. Journal of the Franklin Institute 353 (5), S. 1147 - 1167 (2016)

Benner, P.; Kürschner, P.; Saak, J.: Frequency-Limited Balanced Truncation with Low-Rank Approximations. SIAM Journal on Scientific Computing 38 (1), S. A471 - A499 (2016)

Benner, P.; Saak, J.; Uddin, M. M.: Balancing Based Model Reduction for Structured Index-2 Unstable Descriptor Systems with Application to Flow Control. Numerical Algebra, Control and Optimization 6 (1), S. 1 - 20 (2016)

Benner, P.; Saak, J.; Uddin, M. M.: Structure Preserving Model Order Reduction of Large Sparse Second-Order Index-1 Systems and Application to a Mechatronics Model. Mathematical and Computer Modelling of Dynamical Systems 22 (6), S. 509 - 523 (2016)

Fehr, J.; Heiland, J.; Himpe, C.; Saak, J.: Best Practices for Replicability, Reproducibility and Reusability of Computer-based Experiments exemplified by Model Reduction Software. AIMS Mathematics 1 (3), S. 261 - 281 (2016)

Köhler, M.; Penke, C.; Saak, J.; Ezzatti, P.: Energy-Aware Solution of Linear Systems with Many Right Hand Sides. Computer Science - Research and Development 31 (4), S. 215 - 235 (2016)

Köhler, M.; Saak, J.: On GPU Acceleration of Common Solvers for (Quasi-) Triangular Generalized Lyapunov Equations. Parallel Computing 57, S. 212 - 221 (2016)

Köhler, M.; Saak, J.: On BLAS Level-3 Implementations of Common Solvers for (Quasi-) Triangular Generalized Lyapunov Equations. ACM Transactions on Mathematical Software 43 (1), 3 (2016)

Lang, N.; Saak, J.; Stykel, T.: Balanced Truncation Model Reduction for Linear Time-Varying Systems. Mathematical and Computer Modelling of Dynamical Systems 22 (4), S. 267 - 281 (2016)

Bänsch, E.; Benner, P.; Saak, J.; Weichelt, H. K.: Riccati-Based Boundary Feedback Stabilization of Incompressible Navier-Stokes Flow. SIAM Journal on Scientific Computing 37 (2), S. A832 - A858 (2015)

Lang, N.; Mena, H.; Saak, J.: On the Benefits of the LDL^T Factorization for Large-Scale Differential Matrix Equation Solvers. Linear Algebra and its Applications 480, S. 44 - 71 (2015)

Lang, N.; Saak, J.; Benner, P.; Ihlenfeldt, S.; Nestmann, S.; Schädlich, K.: Towards the Identification of Heat Induction in Chip Removing Processes via an Optimal Control Approach. Production Engineering: Development & Research 9 (3), S. 343 - 349 (2015)

Saak, J.; Remón, A.: Interview: "Energiesparende Algorithmen?: Hochleistungsrechner auf dem Prüfstand". Laborpraxis (39), S. 16 - 17 (2015)

Benner, P.; Kürschner, P.; Saak, J.: Self-Generating and Efficient Shift Parameters in ADI Methods for Large Lyapunov and Sylvester Equations. Electronic Transactions on Numerical Analysis 43, S. 142 - 162 (2014)

Benner, P.; Saak, J.; Schieweck, F.; Skrzypacz, P.; Weichelt, H. K.: A Non-Conforming Composite Quadrilateral Finite Element Pair for Feedback Stabilization of the Stokes Equations. Journal of Numerical Mathematics 22 (3), S. 191 - 220 (2014)

Lang, N.; Saak, J.; Benner, P.: Model Order Reduction for Systems with Moving Loads. at - Automatisierungstechnik 62 (7), S. 512 - 522 (2014)

Benner, P.; Kürschner, P.; Saak, J.: Efficient Handling of Complex Shift Parameters in the Low-Rank Cholesky Factor ADI method. Numerical Algorithms 62 (2), S. 225 - 251 (2013)

Benner, P.; Kürschner, P.; Saak, J.: An Improved Numerical Method for Balanced Truncation for Symmetric Second-Order Systems. Mathematical and Computer Modelling of Dynamical Systems 19 (6), S. 593 - 615 (2013)

Benner, P.; Saak, J.: Numerical Solution of Large and Sparse Continuous Time Algebraic Matrix Riccati and Lyapunov Equations: A State of the Art Survey. GAMM-Mitteilungen 36 (1), S. 32 - 52 (2013)

Benner, P.; Saak, J.; Stoll, M.; Weichelt, H. K.: Efficient Solution of Large-Scale Saddle Point Systems Arising in Riccati-Based Boundary Feedback Stabilization of Incompressible Stokes Flow. SIAM Journal on Scientific Computing 35 , S. S150 - S170 (2013)

Uddin, M. M.; Saak, J.; Kranz, B.; Benner, P.: Computation of a Compact State Space Model for an Adaptive Spindle Head Configuration with Piezo Actuators using Balanced Truncation. Production Engineering 6 (6), S. 577 - 586 (2012)

Benner, P.; Saak, J.: Efficient Balancing-Based MOR for Large-Scale Second-Order Systems. Mathematical and Computer Modelling of Dynamical Systems 17 (2), S. 123 - 143 (2011)

Vettermann, J.; Aumann, Q.; Saak, J.; Benner, P.: Rechenzeitsparende Modellierung. In: Thermo-energetische Gestaltung von Werkzeugmaschinen, S. 199 - 212 (Hg. Brecher, C.). Springer Vieweg, Wiesbaden (2025)

Aumann, Q.; Benner, P.; Saak, J.; Vettermann, J.: Model Order Reduction Strategies for the Computation of Compact Machine Tool Models. In: 3rd International Conference on Thermal Issues in Machine Tools (ICTIMT2023), S. 132 - 145 (Hg. Ihlenfeldt, S.). Springer International Publishing, Cham (2023)

Benner, P.; Köhler, M.; Saak, J.: Matrix Equations, Sparse Solvers: M-M.E.S.S.-2.0.1 -- Philosophy, Features and Application for (Parametric) Model Order Reduction. In: Model Reduction of Complex Dynamical Systems, S. 369 - 392 (Hg. Benner, P.; Breiten, T.; Faßbender, H.; Hinze, M.; Stykel, T. et al.). Birkhäuser, Cham (2021)

Mlinarić, P.; Rave, S.; Saak, J.: Parametric Model Order Reduction using pyMOR. In: Model Reduction of Complex Dynamical Systems, S. 357 - 367 (Hg. Benner, P.; Breiten, T.; Faßbender, H.; Hinze, M.; Stykel, T. et al.). Birkhäuser, Cham, Switzerland (2021)

Rave, S.; Saak, J.: A Non-Stationary Thermal-Block Benchmark Model for Parametric Model Order Reduction. In: Model Reduction of Complex Dynamical Systems, S. 349 - 356 (Hg. Benner, P.; Breiten, T.; Faßbender, H.; Hinze, M.; Stykel, T. et al.). Birkhäuser, Cham, Switzerland (2021)

Bänsch, E.; Benner, P.; Saak, J.; Weichelt, H. K.: Optimal Control-Based Feedback Stabilization of Multi-Field Flow Problems. In: Trends in PDE Constrained Optimization, S. 173 - 188 (Hg. Leugering, G.; Benner, P.; Engell, S.; Griewank, A.; Harbrecht, H. et al.). Birkhäuser, Basel (2014)

Benner, P.; Köhler, M.; Saak, J.: Fast Approximate Solution of the Non-Symmetric Generalized Eigenvalue Problem on Multicore Architectures. In: Parallel Computing Accelerating Computational Science and Engineering (CSE), S. 143 - 152. IOS Press, Amsterdam (2014)

Benner, P.; Saak, J.; Stoll, M.; Weichelt, H. K.: Efficient Solvers for Large-Scale Saddle Point Systems Arising in Feedback Stabilization of Multi-Field Flow Problems. In: System Modeling and Optimization: 26th IFIP TC 7 Conference, CSMO 2013, Klagenfurt, Austria, September 9-13, 2013, Revised Selected Papers, S. 11 - 20 (Hg. Pötzsche, C.; Heuberger , C.; Kaltenbacher, B.; Rendl, F.). Springer, Berlin Heidelberg (2014)