|Dozenten:||Jörg Liesen, Christian Mehl, Volker Mehrmann, Reinhard Nabben, Harry Yserentant|
|LV-Termine:||Do 10:15-11:45 in MA 313|
|Inhalt:||Vorträge von Diplomanden, Doktoranden, Postdocs und manchmal auch Gästen zu aktuellen Forschungsthemen|
|Do 21.4.2006||10:15||MA 376
|Do .4.5.2006||10:15||MA 376
||Simone Bächle||Minimal extension for DAEs from charge and flux oriented MNA|
|Do 11.5.2006||10:15||MA 376
||Martin Bodestedt||The implicit function theorem and perturbation analysis of differential-algebraic equations|
|Do 18.5.2006||10:15||MA 376
||Marion Rauscher||Besov Spaces Part I (Abstract)|
|Do 18.5.2006||im An-
||Hans-Christian Kreusler||Besov Spaces Part II (Abstract)|
|Do 1.6.2006||10:15||MA 376
||Christian Schröder||A QR-like algorithm for the palindromic eigenvalue problem (Abstract)|
|Do 1.6.2006||im An-
||Elena Virnik||An SVD approach to identifying meta-stable states of Markov chains (Abstract)|
|Do 8.6.2006||10:15||MA 376
||Sadegh Jokar||Sparsity and Beyond (Abstract)|
|Do 15.6.2006||10:15||MA 376
||Lena Wunderlich||Structure preserving condensed forms for pairs of Hermitian matrices and matrix valued functions (Abstract)|
|Do 22.6.2006||10:15||MA 376
||Andreas Zeiser||Introduction to wavelets and their applications (Abstract)|
|Do 6.7.2006||10:15||MA 376
||Christian Mense||Multilevel Methods for singular Matrices (Abstract)|
|Do 6.7.2006||im An-
||Lisa Poppe||Delay Differential Algebraic Equations (Abstract)|
Interessenten sind herzlich eingeladen!
Weitere Vorträge siehe auch:
Abstracts zu den Vorträgen:
There are different ways to define Besov spaces. In the first part the classical method using moduli of smoothness is presented whereas in the second part Besov spaces are introduced in the more general framework of interpolation theory. However both definitions lead to identical spaces as the corresponding norms are equivalent.
The talk is on an adapted version of the QR algorithm to transform a square matrix to 'lower-right triangular' form by unitary congruence. The talk is in English. The foils are in German. Interactive matlab examples are planned.
The signal processing literature has been interested in finding sparse solutions of underdetermined linear equation systems. This can be formulated as the minimization of the l_0 quasi-norm. Several researchers have investigated the approximation of this optimization problem with l_1 minimization. In this talk, first we will review some of the recent results in this field. Then we will empirically investigate the exact computation of l_0 minimization problems via branch-and-cut based on reduction to the so-called Maximum feasible subsystem problem. We will also present several heuristics like an adaptation of an algorithm by Mangasarian. With our exact method, we are able for the first time to evaluate the performance of the l_1 minimization and other heuristics for computing approximate l_0 minimal solutions. In particular, we will investigate the behavior of the l_1 minimization when the sparsity of the solutions lies beyond the theoretical limits for which an exact recovery is guaranteed.
The study of matrix pairs or pairs of matrix valued functions is often motivated by applications from linear differential-algebraic equations. In many applications from mechanics or control theory the underlying matrices are symmetric or Hermitian. We present a condensed form under structure preserving congruence transformations for pairs of Hermitian matrices. Further, we show that for pairs of Hermitian matrix valued functions a condensed form only exists if certain additional assumptions hold. There only exists a structure preserving normal form if the corresponding differential-algebraic system is of index less than or equal to 1.
The intention of this talk is to introduce the basic ideas of wavelets. The theory of wavelets will be discussed and application like signal processing and image compression will be briefly explained. However, the main focus will lie on the application of wavelets to the discretization of PDEs.
In this talk we are discussing solution methods for singular systems Ax=b with b in the range of A. One application, where these singular systems arise in, is the simulation of the human blood flow as a Markov chain. Beside easy to satisfy conditions to guarantee convergence for general stationary iteration schemes, we are presenting convergence results for the AMLI- and the MAMLI-methods.
|Impressum||Christian Mehl 5.7.2006|