Sökning: "Bo Kågström"

Visar resultat 6 - 10 av 15 avhandlingar innehållade orden Bo Kågström.

1. 6. Identification and tuning of algorithmic parameters in parallel matrix computations : Hessenberg reduction and tensor storage format conversion

   Författare :Mahmoud Eljammaly; Bo Kågström; Lars Karlsson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis considers two problems in numerical linear algebra and high performance computing (HPC): (i) the parallelization of a new blocked Hessenberg reduction algorithm using Parallel Cache Assignment (PCA) and the tunability of its algorithm parameters, and (ii) storing and manipulating dense tensors on shared memory HPC systems.The Hessenberg reduction appears in the Aggressive Early Deflation (AED) process for identifying converged eigenvalues in the distributed multishift QR algorithm (state-of-the-art algorithm for computing all eigenvalues for dense square matrices). LÄS MER

3. 7. Capacity allocation mechanisms for grid environments

   Författare :Peter Gardfjäll; Erik Elmroth; Bo Kågström; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Grid computing; capacity allocation; allocation enforcement; accounting; Grid-wide fairshare scheduling; Web services; Computer science; Datavetenskap;

   Sammanfattning : During the past decade, Grid computing has gained popularity as a means to build powerful computing infrastructures by aggregating distributed computing capacity. Grid technology allows computing resources that belong to different organizations to be integrated into a single unified system image – a Grid. LÄS MER

4. 8. Algorithms and Library Software for Periodic and Parallel Eigenvalue Reordering and Sylvester-Type Matrix Equations with Condition Estimation

   Författare :Robert Granat; Bo Kågström; Isak Jonsson; Volker Mehrmann; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; periodic eigenvalue problems; product eigenvalue problems; periodic Schur form; periodic eigenvalue reordering; periodic eigenspaces; parallel algorithms; Sylvester-type matrix equations; parallel eigenvalue reordering; condition estimation; Computer science; Datavetenskap;

   Sammanfattning : This Thesis contains contributions in two different but closely related subfields of Scientific and Parallel Computing which arise in the context of various eigenvalue problems: periodic and parallel eigenvalue reordering and parallel algorithms for Sylvestertype matrix equations with applications in condition estimation.Many real world phenomena behave periodically, e. LÄS MER

5. 9. Software tools for matrix canonical computations and web-based software library environments

   Författare :Pedher Johansson; Bo Kågström; Erik. Elmroth; Alan Edelman; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canonical structure; Jordan canonical form; controllability; StratiGraph; Matlab toolbox; Kronecker canonical form; matrix; matrix pencil; perturbation theory; closure hirerarchy; matrix stratification; control system; observability; Numerical analysis; Numerisk analys;

   Sammanfattning : This dissertation addresses the development and use of novel software tools and environments for the computation and visualization of canonical information as well as stratification hierarchies for matrices and matrix pencils. The simplest standard shape to which a matrix pencil with a given set of eigenvalues can be reduced is called the Kronecker canonical form (KCF). LÄS MER

7. 10. Tools for Control System Design : Stratification of Matrix Pairs and Periodic Riccati Differential Equation Solvers

   Författare :Stefan Johansson; Bo Kågström; Erik Elmroth; Paul Van Dooren; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; control system design; stratification; controllability; observability; matrix pair; canonical forms; linear quadratic regulator; periodic systems; periodic Riccati differential equation; Computer science; Datavetenskap; Numerical Analysis; numerisk analys;

   Sammanfattning : Modern control theory is today an interdisciplinary area of research. Just as much as this can be problematic, it also provides a rich research environment where practice and theory meet. This Thesis is conducted in the borderline between computing science (numerical analysis) and applied control theory. LÄS MER