National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Large-scale geosimulations using GEM and trilions
Blaheta, Radim ; Jakl, Ondřej ; Hrtus, Rostislav ; Kolcun, Alexej ; Kohut, Roman ; Starý, Jiří ; Turan, E.
The project deals with efficient solution of singular symmetric positive semidefinite problems. Our motivation arises from the \nneed to solve special problems of geotechnics, e.g. to perform upscaling analysis of geocomposites. In that and other applications we have to solve boundary problems with pure Neumann boundary conditions. We show that the stabilised PCG method with various preconditioners is a good choice for systems resulting from the numerical solution of Neumann problems, or more generally problems with a known small dimensional null space. The work was also taken as an opportunity to compare parallel implementations of the orresponding solvers, namely implementations in the in-house finite element software GEM and implementations employing components of the general Trilinos library. The studies show that the solvers based on GEM are highly competitive with its recognised counterpart.
Optimization methods for inverse problems with energy norm
Hrtus, Rostislav ; Haslinger, Jaroslav ; Blaheta, Radim
The paper deals with the application of the energy norm in the inverse problem which is based on a minimization of a nonlinear least squares function. Three different parameter distribution examples are solved by the steepest descent, nonlinear conjugate gradient and Newton methods. Efficiency comparison is also presented.
Fulltext: content.csg - Download fulltextPDF
Plný tet: UGN_0438756 - Download fulltextPDF
High performance computing in micromechanics
Blaheta, Radim ; Hrtus, Rostislav ; Jakl, Ondřej ; Starý, Jiří
By micromechanics we understand analysis of the macroscale response of materials through investigation of processes in their microstructure. Here by the macroscale, we mean the scale of applications, where we solve engineering problems involving materials like different metals and composites in aircraft design or rocks and concrete in a dam construction. Different applications are characterized by different characteristic size. At macroscale the materials mostly look as homogeneous or they are idealized as homogeneous or piecewise homogeneous. A substantial heterogeneity is hidden and appears only after more detailed zooming view into the material.
Fulltext: content.csg - Download fulltextPDF
Plný tet: UGN_0426823 - Download fulltextPDF

Interested in being notified about new results for this query?
Subscribe to the RSS feed.