Tobias Gradl

Learn More
The hierarchical hybrid grid framework supports the parallel implementation of multigrid solvers for finite element problems. Specifically, it generates extremely fine meshes by using a structured refinement of an unstructured base mesh. For special problems with piecewise uniform material parameters, this leads to the possibility of stencil-based(More)
Making multigrid algorithms run efficiently on large parallel computers is a challenge. Without clever data structures the communication overhead will lead to an unacceptable performance drop when using thousands of processors. We show that with a good implementation it is possible to solve a linear system with 10 11 unknowns in about 1.5 minutes on almost(More)
Quantum control plays a key role in quantum technology, e.g. for steering quantum hardware systems, spectrometers or supercon-ducting solid-state devices. In terms of computation, quantum systems provide a unique potential for coherent parallelisation that may exponentially speed up algorithms as in Shor's prime factorisation. Translating quantum software(More)
While multicore architectures are becoming usual on desktop machines, supercomputers are approaching million cores. The amount of memory and compute power on current clusters enable us e.g. to obtain a resolution of in excess (10 000) 3 =10 12 degrees of freedom. However, on the downside we are forced to partition our domain into extremely many(More)
In this paper a local Fourier analysis for multigrid methods on tetrahedral grids is presented. Different smoothers for the discretization of the Laplace operator by linear finite elements on such grids are analyzed. A four-color smoother is presented as an efficient choice for regular tetrahedral grids, whereas line and plane relaxations are needed for(More)
Multigrid methods are among the most efficient and widespread methods for solving large linear systems of equations that arise, for example, from the discretization of partial differential equations. In this paper we introduce a new approach for optimizing the computational cost of the full multigrid method to achieve a given accuracy by determining the(More)
The research data landscape of the arts and humanities is characterized by a high degree of heterogeneity. To improve interoperability, recent initiatives and research infrastructures are encouraging the use of standards and best practices. However, custom data models are often considered necessary to exactly reflect the requirements of a particular(More)