Search for dissertations about: "fractional operators"

Showing result 1 - 5 of 16 swedish dissertations containing the words fractional operators.

  2. 1. Fractional Calculus and Linear Viscoelasticity in Structural Dynamics

    Author : Mikael Enelund; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linear viscoelasticity; convolution integrals; anisotropy; structural modeling; finite elements; material damping; time integration; internal variables; relaxation; fractional calculus; creep; Mittag-Leffler functions;

    Abstract : The use of linear viscoelasticity together with fractional calculus in time-domain structural modeling is studied. Both constitutive and structural aspects are investigated. READ MORE

  4. 2. New weighted inequalities with applications to pseudodifferential operators

    Author : Stefan Eilertsen; Per-Anders Ivert; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Weighted integral inequalities; fractional Laplacian; Dirichlet problem; behavior near the boundary; special functions;

    Abstract : This thesis is devoted to weighted integral inequalities and their applications to the  study of boundary behavior of solutions to Dirichlet's problem for fractional powers of the Laplacian.We obtain a necessary and sufficient condition on μ for the operator (—Δ)μin R 0 , 0 ... READ MORE

  5. 3. Numerical Approximation of Solutions to Stochastic Partial Differential Equations and Their Moments

    Author : Kristin Kirchner; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Petrov– Galerkin discretizations; Strong and weak convergence; Fractional operators; Finite element methods; Space-time variational problems; Tensor product spaces; Stochastic partial differential equations; White noise; Petrov– Galerkin discretizations;

    Abstract : The first part of this thesis focusses on the numerical approximation of the first two moments of solutions to parabolic stochastic partial differential equations (SPDEs) with additive or multiplicative noise. More precisely, in Paper I an earlier result (A. Lang, S. Larsson, and Ch. READ MORE

  6. 4. Selected Topics in Mathematical Modelling: Machine Learning and Tugs-of-War

    Author : Carmina Fjellström; Kaj Nyström; Andrea Pascucci; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Machine learning; Neural networks; LSTM; Financial forecasting; Time series analysis; Stochastic gradient descent; Diffusion map; Dimension reduction; Tug-of-war games; Fractional heat operator; Mean value property; Infinity fractional heat operators; Dynamic programming principle; p-Laplacian; Infinity Laplacian; Kolmogorov equation; Stochastic games; Viscosity solutions; Tillämpad matematik och statistik; Applied Mathematics and Statistics;

    Abstract : This thesis concerns selected topics in mathematical modelling, namely in machine learning and stochastic games called tugs-of-war. It consists of four scientific articles. The first and second are about machine learning topics, while the third and fourth articles are about tug-of-war games. READ MORE

  7. 5. Fractional moving blood volume in fetal organs estimated using power Doppler ultrasound

    Author : Edgar Hernandez-Andrade; Lund Obstetrik och gynekologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; reproduction; andrology; gynaecology; Obstetrics; sexuality; Obstetrik; gynekologi; andrologi; reproduktion; sexualitet; fetal adrenal gland; fetal lung; radionuclear microspheres; fetal lamb; perfusion; fetus; Power Doppler ultrasound; fractional moving blood volume;

    Abstract : Power Doppler ultrasound (PDU) is a sensitive technique to detect slow blood movement. The aim of the present study was to develop a standardized method for quantification of the PDU signals recorded from a specific region of interest (ROI) within fetal organs. READ MORE