Spring 2007, Math 6425, CRN: 15516 Course Title: Approximation of Dynamical Systems Course Meeting Time: TR 3:30pm-4:45pm Instructor: Serkan Gugercin Course Web-page: http://math.vt.edu/people/gugercin/Math6425.htm The course will cover topics related to approximation (model reduction) of dynamical systems represented by sets of coupled differential or difference equations. The goal is to generate a simpler dynamical system, i.e., one being represented by smaller number of differential/difference equations, that approximates the behavior of the original system well in certain norms. Most model reduction techniques can be represented as a projection. In this course we will look at two main classes of projection-based model reduction: (1) SVD-based model reduction and (2) Interpolation (Krylov) based model reduction. The first category is related to the optimal approximation of constant matrices in the 2-induced norm. Balanced Truncation and Optimal Hankel Norm Approximation are the two most common methods in the category. Despite their appealing theoretical properties, the computational requirements associated with these methods make them impractical for true large-scale settings. The second category, on the other hand, is connected to interpolation/Pade approximation. Most common techniques in this category are the Arnoldi and Lanczos procedures, and the rational Krylov methods. Unlike the SVD-based methods, these methods enjoy a great computational efficiency, but in some cases might lack rigorous theoretical guarantees. We will analyze both classes of methods in detail and present comparisons/similarities. If time allows, Proper Orthogonal Decomposition (yet another projection-based technique) will be discussed as well. Several examples from various science and engineering disciplines will be presented. For more details, see the course web-page at http://math.vt.edu/people/gugercin/Math6425.htm