ubc Efficient Numerical Solution of Large Scale Algebraic Matrix Equations in PDE Control and Model Order Reduction 2009-10-21 [Electronic ed.] prv Universitätsbibliothek Chemnitz Universitätsbibliothek Chemnitz, Chemnitz Fakultät für Mathematik male Emden male male male male Matrix Lyapunov and Riccati equations are an important tool in mathematical systems theory. They are the key ingredients in balancing based model order reduction techniques and linear quadratic regulator problems. For small and moderately sized problems these equations are solved by techniques with at least cubic complexity which prohibits their usage in large scale applications. Around the year 2000 solvers for large scale problems have been introduced. The basic idea there is to compute a low rank decomposition of the quadratic and dense solution matrix and in turn reduce the memory and computational complexity of the algorithms. In this thesis efficiency enhancing techniques for the low rank alternating directions implicit iteration based solution of large scale matrix equations are introduced and discussed. Also the applicability in the context of real world systems is demonstrated. The thesis is structured in seven central chapters. After the introduction chapter 2 introduces the basic concepts and notations needed as fundamental tools for the remainder of the thesis. The next chapter then introduces a collection of test examples spanning from easily scalable academic test systems to badly conditioned technical applications which are used to demonstrate the features of the solvers. Chapter four and five describe the basic solvers and the modifications taken to make them applicable to an even larger class of problems. The following two chapters treat the application of the solvers in the context of model order reduction and linear quadratic optimal control of PDEs. The final chapter then presents the extensive numerical testing undertaken with the solvers proposed in the prior chapters. Some conclusions and an appendix complete the thesis. 500 Lineare Algebra Numerische Mathematik Partielle Differentialgleichung Balanciertes Abschneiden LQR für PDEs Lyapunovgleichung Modellreduktion Riccatigleichung urn:nbn:de:bsz:ch1-200901642 Technische Universität Chemnitz dgg Technische Universität Chemnitz, Chemnitz Jens Saak 1975-03-31 aut Peter Benner Prof. Dr. dgs rev Enrique S. Quintana-Ortí Prof. Dr. rev Ekkehard W. Sachs Prof. Dr. rev eng 2009-07-06 2009-09-25 born digital doctoral_thesis