Search for dissertations about: "exponential decay"

Showing result 16 - 20 of 32 swedish dissertations containing the words exponential decay.

  2. 16. Degenerating Orr-Sommerfeld eigenmodes and development of three-dimensional perturbations

    Author : Rajaratnam Shanthini; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Abstract : Degeneracies of temporally damped Orr-Sommerfeld eigenmodes are studied primarily for plane Poiseuille flow. The discrete spectrum of the eigenmodes is shown to possess infinitely many degeneracies, each appearing at a certain combination of k (the modulus of resultant wavenumber) and α R (the streamwise wavenumber times the Reynolds number). READ MORE

  4. 17. Parallelization of dynamic algorithms for electronic structure calculations

    Author : Anton G. Artemov; Emanuel H. Rubensson; Maya Neytcheva; Bo Kågström; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; parallelization; task-based programming; matrix algorithms; sparse matrices; inverse factorization; localized computations; density matrix methods; electronic structure calculations; Scientific Computing; Beräkningsvetenskap;

    Abstract : The aim of electronic structure calculations is to simulate behavior of complex materials by resolving interactions between electrons and nuclei in atoms at the level of quantum mechanics. Progress in the field allows to reduce the computational complexity of the solution methods to linear so that the computational time scales proportionally to the size of the physical system. READ MORE

  5. 18. Optical Properties of Single Silicon Quantum Dots

    Author : Federico Pevere; Jan Linnros; Uwe Kortshagen; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; silicon; nanocrystals; quantum dots; photoluminescence; optics; emission; absorption; Fysik; Physics;

    Abstract : For over 60 years silicon (Si) has dominated the semiconductor microelectronics industry mainly due to its abundance and good electrical and material properties. The advanced processing technology of Si has made it the workhorse for photovoltaics industry as well. READ MORE

  6. 19. Two-Barrier Problems in Applied Probability: Algorithms and Analysis

    Author : Mats Pihlsgård; Matematisk statistik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Statistics; operations research; programming; actuarial mathematics; Statistik; Matematik; Mathematics; Naturvetenskap; Natural science; Reflection; Stochastic processes; Applied probability; Queueing; operationsanalys; programmering; aktuariematematik;

    Abstract : This thesis consists of five papers (A-E). In Paper A, we study transient properties of the queue length process in various queueing settings. We focus on computing the mean and the Laplace transform of the time required for the queue length starting at $x0. We define the loss rate due to the reflection. READ MORE

  7. 20. An experimental investigation of disturbance growth in boundary layer flows

    Author : Thomas Kurian; P. Henrik Alfredsson; Jens H. M. Fransson; Edward B. White; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; Strömningsmekanik; Other engineering mechanics; Övrig teknisk mekanik;

    Abstract : This thesis deals with the early stages of transition to turbulence in two different baseflows, namely the Falkner-Skan-Cooke boundary layer (FSC) and the asymptotic suction boundary layer (ASBL). Grid-generated turbulence is studied in order to characterise the isotropy levels, free-stream turbulence levels and characteristic length scales that will be present in the receptivity study. READ MORE