Sökning: "diffusion approximation"
Visar resultat 1 - 5 av 21 uppsatser innehållade orden diffusion approximation.
1. Estimating Diffusion Tensor Distributions With Neural Networks
Master-uppsats, Linköpings universitet/Algebra, geometri och diskret matematik; Linköpings universitet/Tekniska fakultetenSammanfattning : 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. LÄS MER
2. Solving the incompressible Navier-Stokes equations in 3-D to model gas flow in a room
Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen för beräkningsvetenskapSammanfattning : The thesis proposes to model the flow of gases in a room by solving the incompressible Navier-Stokes equations in three dimensions. The transportationof scalars such as temperature and concentration of CO2 is modeled by solving the advection-diffusion equation, and the effects of temperature on thevelocity is accounted for by employing the Boussinesq approximation. LÄS MER
3. Filtering aspects
Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)Sammanfattning : In this report, a Fourier spectral approximation of the solution to the linear convection--diffusion equation for initial conditions of different smoothness, and for Burger's equation for the initial condition f(x) = sin(x), was constructed, and implemented. Three different filters (Cesàro, Lanczos, and 4--th order exponential cutoff) were either applied to the initial condition or to the numerical approximation after the last integration step has been performed. LÄS MER
4. Approximating Quasistationary Distributions Using Deep Learning
Master-uppsats, KTH/Matematisk statistikSammanfattning : We study a class of It\={o} diffusion processes on domains with smooth boundary, at which the process is killed. Such a process, when conditioned on non-extinction, gives rise to a stationary state known as a \emph{quasistationary distribution} (QSD). LÄS MER
5. Squaring VEGAS -- Multidimensional Integration Using 2D Correlations
Kandidat-uppsats, Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisationSammanfattning : Multidimensional integrals are used in many areas of physics; electrodynamics, quantum mechanics and statistical physics, to name a few. Many integrals can not be solved analytically, but can instead be approximated numerically. VEGAS is a Monte Carlo integration algorithm, which specializes it in approximating multidimensional integrals. LÄS MER