Sökning: "High frequency approximations"

Visar resultat 26 - 30 av 36 avhandlingar innehållade orden High frequency approximations.

  1. 26. On Lorentz Invariance, Regularity and Global Existence for Kinetic Equations

    Författare :Håkan Andreasson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : [A1] Regularity of the gain term and strong L1 convergence to equilibrium for the relativistic Boltzmann equation. The main purpose of the paper is to show that the gain term of the relativistic collision operator is regularizing. This is a generalization of P.L. LÄS MER

  3. 27. Dispersive and polarimetric properties of waves in space plasma

    Författare :Jan Bergman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Space Physics; rymdfysik;

    Sammanfattning : Various aspects regarding dispersive and polarimetric properties of waves in space plasma are discussed from a theoretical viewpoint, which is extended to include numerical as well as experimental studies. From a more technical viewpoint, two scientific instruments are described. LÄS MER

  4. 28. System identification in alternative shift operators with applications and some other topics

    Författare :Britta Fischer; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reglerteknik; Control Engineering;

    Sammanfattning : This thesis mainly concentrates on two issues of system identification, namely identification for controller design and identification with orthonormal basis functions. In identification for controller design one seeks to obtain sufficient knowledge about the plant to design a high-performance controller. LÄS MER

  5. 29. Implementation and optimization of partial element equivalent circuit-based solver

    Författare :Danesh Daroui; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

    Sammanfattning : The Partial Element Equivalent Circuit (PEEC) method is an integral equation based full-wave approach to solve combined circuit and electromagnetic problems in the time and frequency domain. Using PEEC, an electromagnetic problem is transferred to the circuit domain and then solved using circuit theory which gives PEEC a high flexibility to be used in combined electromagnetic and circuit modeling problems. LÄS MER

  7. 30. Homogenization with applications in lubrication theory

    Författare :Afonso Fernando Tsandzana; Anders Holmbom; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : In this licentiate thesis we study some mathematical problems in hydrodynamic lubrication theory. It is composed of two papers (A and B) and a complementary appendix. Lubrication theory is devoted to fluid flow in thin domains. The main purpose of lubrication is to reduce friction and wear between two solid surfaces in relative motion. LÄS MER