Sökning: "eigenvalue problem"

Visar resultat 16 - 20 av 62 avhandlingar innehållade orden eigenvalue problem.

1. 16. Improving the efficiency of eigenvector-related computations

   Författare :Angelika Beatrix Schwarz; Lars Karlsson; Bo Kågström; Carl Christian Kjelgaard Mikkelsen; Miroslav Tůma; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-performance computing; standard non-symmetric eigenvalue problem; triangular Sylvester equation; tiled algorithms; task parallelism;

   Sammanfattning : An effective strategy in dense linear algebra is the design of algorithms as tiled algorithms. Tiled algorithms that express the bulk of the computation as matrix-matrix operations (level-3 BLAS) have proven successful in achieving high performance on cache-based architectures. LÄS MER

3. 17. Reliable hp finite element computations of scattering resonances in nano optics

   Författare :Juan Carlos Araujo-Cabarcas; Christian Engström; David Cohen; Mats G. Larson; Jeffrey Ovall; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scattering resonances; Helmholtz problems; pseudospectrum; Lippmann-Schwinger equation; finite element methods; nonlinear eigenvalue problems; spurious solutions;

   Sammanfattning : Eigenfrequencies are commonly studied in wave propagation problems, as they are important in the analysis of closed cavities such as a microwave oven. For open systems, energy leaks into infinity and therefore scattering resonances are used instead of eigenfrequencies. LÄS MER

4. 18. On Spectrum Sensing for Secondary Operation in Licensed Spectrum : Blind Sensing, Sensing Optimization and Traffic Modeling

   Författare :Mohamed Hamid; Ben Slimane Slimane; Niclas Björsell; Octavia Dobre; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cognitive Radio; Spectrum Sensing; Sensing Optimization; Blind Sensing; Traffic Modelling; Energy detection; Maximumum-minimum Eigenvalue Detection; Discriminant anlysis; Informations- och kommunikationsteknik; Information and Communication Technology;

   Sammanfattning : There has been a recent explosive growth in mobile data consumption. This, in turn, imposes many challenges for mobile services providers and regulators in many aspects. One of these primary challenges is maintaining the radio spectrum to handle the current and upcoming expansion in mobile data traffic. LÄS MER

5. 19. On eigenvalues of the Schrödinger operator with a complex-valued polynomial potential

   Författare :Per Alexandersson; Boris Shapiro; Ilpo Laine; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; schroedinger; even spectral determinant polynomial potential eigenvalue; Mathematical analysis; Analys; Mathematics; matematik;

   Sammanfattning : In this thesis, we generalize a recent result of A. Eremenko and A. Gabrielov on irreducibility of the spectral discriminant for the Schroedinger equation with quartic potentials. LÄS MER

7. 20. Two-scale Convergence and Homogenization of Some Partial Differential Equations

   Författare :Hermann Douanla Yonta; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Homogenization. Two-scale convergence. Perforated domains. Eigenvalue problem. Ergodic algebra. Algebra with mean value. Gelfand transform. Sigma-convergence. Navier-Stokes equation. Deterministic fissured medium.; Homogenization. Two-scale convergence. Perforated domains. Eigenvalue problem. Ergodic algebra. Algebra with mean value. Gelfand transform. Sigma-convergence. Navier-Stokes equation. Deterministic fissured medium.;

   Sammanfattning : .... LÄS MER