National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Two-dimensional model of electron collisions with molecules
Ivánek, Richard ; Houfek, Karel (advisor) ; Čížek, Martin (referee)
In this master thesis we study convergence of selected iterative methods applied to linear systems originating from the finite element method, dis- crete variable representation and exterior complex scaling in the context of models of electron collisions with molecules. Benchmarks and comparisons with direct methods are made and convergence of methods is analyzed for a one-dimensional two-channel model and a more realistic two-dimensional model of four different molecular systems. Along the way, a review of the mentioned numerical methods and solvers is presented as well as a discussion of the sparsity patterns and numbers of non-zero elements of the used matrix representations. Finally, possible pathologies of preconditioners are shown.
Beahvior of the solutions to the wave equation in compactified hyperboloidal slicing
Ivánek, Richard ; Ledvinka, Tomáš (advisor) ; Kofroň, David (referee)
In this bachelor thesis we discuss the effects of compactification and hyperboloidal slicing of spacetime in the numerical solution of wave equation primarily for their appli- cation in numerical relativity. The aim was to find the pros and cons of these concepts, to illustrate expected problems using diagrams and to rate the results obtained in spe- cific model problems. A brief explanation and demonstration of relevant numerical me- thods, hyperbolic Cauchy hypersurfaces, compactification and causal diagrams is a part of the thesis. As a conclusion, the effect of compactification and slicing on the accuracy of differential and integrational schemes was compared as well as the effect of discrete representation on the quality of initial data. 1

See also: similar author names
5 Ivánek, Radim
3 Ivánek, Robert
Interested in being notified about new results for this query?
Subscribe to the RSS feed.