Sökning: "elliptical"

Visar resultat 1 - 5 av 52 avhandlingar innehållade ordet elliptical.

  1. 1. Rank Estimation in Elliptical Models Estimation of Structured Rank Covariance Matrices and Asymptotics for Heteroscedastic Linear Regression

    Detta är en avhandling från Uppsala : Universitetsbiblioteket

    Författare :Kristi Kuljus; Uppsala universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; elliptical distributions; multivariate ranks; rank covariance matrix; linear rank regression; heteroscedastic errors; linear rank statistics; MATHEMATICS Applied mathematics Mathematical statistics; MATEMATIK Tillämpad matematik Matematisk statistik;

    Sammanfattning : This thesis deals with univariate and multivariate rank methods in making statistical inference. It is assumed that the underlying distributions belong to the class of elliptical distributions. LÄS MER

  2. 2. Elliptical Adaptive Structuring Elements for Mathematical Morphology

    Detta är en avhandling från Luleå tekniska universitet

    Författare :Anders Landström; Luleå tekniska universitet.; [2014]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : As technological advances drives the evolution of sensors as well as the systems using them, processing and analysis of multi-dimensional signals such as images becomes more and more common in a wide range of applications ranging from consumer products to automated systems in process industry. Image processing is often needed to enhance or suppress features in the acquired data, enabling better analysis of the signals and thereby better use of the system in question. LÄS MER

  3. 3. Propagation of weak shock waves in an elliptical cavity

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Göran Gustafsson; [1985]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : The propagation of weak shock waves in a planar elliptical cavity is studied theoretically and experimentally. The results are of interest in the design of an elliptical high-speed water jet generator operating in a transient fashion with electrically generated shocks in the acoustic regime. LÄS MER

  4. 4. Dissipative formation of galaxies in hierarchical cosmology

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :John Hultman; Uppsala universitet.; [1998]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; merical methods; hydrodynamics; galaxies: formation; galaxies: elliptical; galaxies: structure; star formation; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : A description and detailed tests of a numerical code for simulations of galaxy formation is presented. The dynamics is followed with fully adaptive and Lagrangian Smooth Particle Hydrodynamics (SPH) combined with a gravitational tree method. The severe numerical problem of sub-resolution clustering is solved by merging of gas particles. LÄS MER

  5. 5. Computational Modelling for Cavitation and Tip Vortex Flows

    Detta är en avhandling från ; Chalmers tekniska högskola; Gothenburg

    Författare :Abolfazl Asnaghi; [2018]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cavitation; SST k − ω; OpenFOAM; Propeller; LES; Numerical simulation; Cur- vature correction; Elliptical foil; Inception; Twisted Delft foil;

    Sammanfattning : Cavitation often brings negative effects, such as performance degradation, noise, vibration, and material damage, to marine propulsion systems, but for optimum performance, cavitation is almost inevitable. Therefore, it is necessary to better understand cavitation in order to maximize the performance without encounter- ing severe problems. LÄS MER