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Showing result 1 - 5 of 156 essays matching the above criteria.

  1. 1. Estimating Diffusion Tensor Distributions With Neural Networks

    University essay from Linköpings universitet/Algebra, geometri och diskret matematik; Linköpings universitet/Tekniska fakulteten

    Author : Rimaz Nismi; [2024]
    Keywords : Diffusion; Magnetic Resonance Imaging; MRI; Neural Networks; Optimal transport; Earth mover s distance; Sinkhorn distance;

    Abstract : Magnetic Resonance Imaging (MRI) is an essential healthcare technology, with diffusion MRI being a specialized technique. Diffusion MRI exploits the inherent diffusion of water molecules within the human body to produce a high-resolution tissue image. An MRI image contains information about a 3D volume in space, composed of 3D units called voxels. READ MORE

  3. 2. Effects of Ultrafast Ionization in X-ray Coherent Diffraction Imaging

    University essay from KTH/Kemi

    Author : Arezu Sehati; [2023]
    Keywords : Coherent Diffraction Imaging; X-ray Free Electron Lasers; Refractive index; Core-shell nanoclusters; Rare-gas ionization; Koherent Diffraktionsavbildning; Röntgenfrielektronlaser; Brytningsindex; Core-shell-nanokluster; Ädelgasjonisering;

    Abstract : Koherent Diffraktionsavbildning med en intensiv röntgenpuls från en Frielektronlaser har möjliggjort strukturbestämning av isolerade nanopartiklar som inte går att studera med hjälp av konventionella metoder, så som elektronmikroskopi. En mycket kort pulslängd tillsammans med spridningssignalens beroende av objektets elektroniska struktur medför också möjligheten att studera inducerad ultrasnabb dynamik med denna teknik. READ MORE

  4. 3. Numerical Simulations of Resonant Tunnelling Diodes

    University essay from KTH/Skolan för teknikvetenskap (SCI)

    Author : Love Sundström; Alexander Holmström Janeld; [2023]
    Keywords : Quantum mechanics; numerical methods; resonant tunnelling diode;

    Abstract : In this thesis, four different numerical techniques are implemented for the purpose of simulating resonant tunnelling diodes (RTDs). The chosen methods were: piecewise constant transfer matrix (TMM-C), piecewise linear transfer matrix (TMM-L), quantum transmitting boundary method (QTBM), and the Crank-Nicolson method (CN). READ MORE

  5. 4. Discussion of Python Implementation Techniques for Discontinuous Galerkin Methods

    University essay from Lunds universitet/Matematik (naturvetenskapliga fakulteten); Lunds universitet/Matematikcentrum

    Author : Ulf Vestberg; [2023]
    Keywords : Best approximation; Orthogonal polynomials; Legendre polynomials; Integration; Full tensor product; Sum-factorization; Dune; Mathematics and Statistics;

    Abstract : This paper discusses implementation techniques for integration methods within the Discontinuous Galerkin Methods. These methods are used to approximate solutions for differential equations. To do so, one must compute a polynomial, which is an approximation of the used function. READ MORE

  6. 5. Electron-skyrmion systems, in and out of equilibrium, and isolated or contacted to reservoirs

    University essay from Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

    Author : Emil Adam Jonatan Östberg; [2023]
    Keywords : skyrmion; skyrmions; NEGF; freen s function; quantum transport; non-equlibrium; topology; topological charge; skyrmionics; current induced; open system; Physics and Astronomy;

    Abstract : A Kondo lattice skyrmion model in contact with a macroscopic environment is simulated to explore skyrmion dynamics, which is an extension of previous work. The system is simulated using non-equilibrium Green's functions within the generalized Kadanoff-Baym ansatz and the wide band limit. READ MORE