Search for dissertations about: "forward backward"

Showing result 1 - 5 of 77 swedish dissertations containing the words forward backward.

2. 1. Backward and Forward Nonlinear Optical Processes in Potassium Titanyl Phosphate

   Author : Kjell Martin Mølster; Fredrik Laurell; Valdas Pasiskevicius; Ulf L. Österberg; Stefano Taccheo; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; QPM; PPKTP; Nonlinear Optics; Backward second-harmonic; BWOPO; OPO; parametric devices; QPM; Ickelinär Optik; BWOPO; OPO; PPKTP; QPM; kvasifasematching; ikkelinæer optikk; bakovervendt parametrisk oscillator; optisk parametrisk oscillator; PPKTP; Optics and Photonics; Optik och fotonik; Physics; Fysik;

   Abstract : Second-order nonlinear optical processes generate radiation across a broad spectrum, including UV and the far-infrared. In this thesis, new light sources in the near(NIR) and mid infrared (MIR) using three-wave mixing geometries in periodically poled potassium titanyl phosphate (PPKTP) is studied. READ MORE

4. 2. On Numerical Methods for the Diffusion Equation Subject to Non-Local Boundary Conditions

   Author : Gunnar Ekolin; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; forward Euler method; backward Euler method; the Crank-Nicolson method; heat equation; Galerkin finite element methods; backward Euler method;

   Abstract : In the first paper three different finite difference methods for solving the heat equation in one space dimension with boundary conditions containing integrals over the interior of the interval are considered. The schemes are based on the forward Euler, the backward Euler and the Crank-Nicolson methods. Error estimates are derived in maximum norm. READ MORE

5. 3. Three-Dimensional Modelling and Inversion of DC resistivity and Time Domain EM data using Multi-Resolution Framework

   Author : Jingyu Gao; Thorkild Maack Rasmussen; Maxim Smirnov; Bülent Tezkan; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; DC Resistivity; time-domain electromagnetic; forward modelling; data inversion; Prospekteringsgeofysik; Exploration Geophysics;

   Abstract : 3-D forward modelling and inversion techniques play an important role in data interpretation, but they are still computationally challenging tasks. Therefore, this thesis aims to improve forward modelling and inversion performance using novel multi-resolution (MR) grid approach. READ MORE

6. 4. Two-Dimensional Signal Root Estimation in Blind Multichannel Impact Response Analysis

   Author : Joakim Axmon; Matematisk statistik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; forestry; Silviculture; detection of decay.; Norway spruce; X-texture mode; signal subspace enhancement; partial forward-backward averaging; ESPRIT; state-space; Prony; frequency analysis; SIMO; impact response; Modal analysis; impact excitation; forestry technology; Skogsvetenskap; skogsbruk; skogsteknik; Electrical engineering; Elektroteknik; Signal processing; Signalbehandling;

   Abstract : This doctoral dissertation concerns two-dimensional frequency estimation for modal analysis of single-input multiple-output impact responses from circularly cylindrical objects. The application is within detection of internal defects in trunks of spruce. READ MORE

7. 5. Practical methods for Gaussian mixture filtering and smoothing

   Author : Abu Sajana Rahmathullah; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : In many applications, there is an interest in systematically and sequentially estimating quantities of interest in a dynamical system, using indirect and inaccurate sensor observations. There are three important sub-problems of sequential estimation: prediction, filtering and smoothing. READ MORE