Search for dissertations about: "manifolds"

Showing result 1 - 5 of 119 swedish dissertations containing the word manifolds.

2. 1. Entropy and Speech

   Author : Mattias Nilsson; Bastian Kleijn; Sören Holdt Jensen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; speech representation; energy concentration; entropy estimation; manifolds; Acoustics; Akustik;

   Abstract : In this thesis, we study the representation of speech signals and the estimation of information-theoretical measures from observations containing features of the speech signal. The main body of the thesis consists of four research papers. Paper A presents a compact representation of the speech signal that facilitates perfect reconstruction. READ MORE

4. 2. Algorithms in data mining using matrix and tensor methods

   Author : Berkant Savas; Lars Eldén; Lieven De Lathauwer; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Volume; Minimization criterion; Determinant; Rank deficient matrix; Reduced rank regression; System identification; Rank reduction; Volume minimization; General algorithm; Handwritten digit classification; Tensors; Higher order singular value decomposition; Tensor approximation; Least squares; Tucker model; Multilinear algebra; Notation; Contraction; Tensor matricization; Newton s method; Grassmann manifolds; Product manifolds; Quasi-Newton algorithms; BFGS and L-BFGS; Symmetric tensor approximation; Local intrinsic coordinates; Global embedded coordinates; ; Numerical analysis; Numerisk analys;

   Abstract : In many fields of science, engineering, and economics large amounts of data are stored and there is a need to analyze these data in order to extract information for various purposes. Data mining is a general concept involving different tools for performing this kind of analysis. READ MORE

5. 3. Computation and Analysis of EGR Mixing in Internal Combustion Engine Manifolds

   Author : Alexander Sakowitz; Laszlo Fuchs; Angelo Onorati; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent Mixing; Large Eddy Simulation; URANS; Internal Combustion Engines; Intake Manifolds; T-junction; Exhaust Gas Recirculation;

   Abstract : This thesis deals with turbulent mixing processes occurring in internal combustion engines, when applying exhaust gas recirculation (EGR). EGR is a very efficient way to reduce emissions of nitrogen oxides (NOx) in internal combustion engines. READ MORE

6. 4. Oxidation and corrosion fatigue aspects of cast exhaust manifolds

   Author : Madeleine Ekström; Stefan Jonsson; Ulf Olofsson; Babette Tonn; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cast exhaust manifolds; high-temperature corrosion; high-temperature low-cycle fatigue; high-temperature corrosion fatigue; ductile cast irons; cast stainless steel; Materials Science and Engineering; Teknisk materialvetenskap;

   Abstract : Emission regulations for heavy-duty diesel engines are becoming increasingly restrictive to limit the environmental impacts of exhaust gases and particles. Increasing the specific power output of diesel engines would improve fuel efficiency and greatly reduce emissions, but these changes could lead to increased exhaust gas temperature, increasing demands on the exhaust manifold material. READ MORE

7. 5. Manifolds in Image Science and Visualization

   Author : Anders Brun; Hans Knutsson; Magnus Herberthson; Carl-Fredrik Westin; Roland Wilson; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; manifold learning; image analysis; signal processing; diffusion tensor mri; Medical engineering; Medicinsk teknik;

   Abstract : A Riemannian manifold is a mathematical concept that generalizes curved surfaces to higher dimensions, giving a precise meaning to concepts like angle, length, area, volume and curvature. A glimpse of the consequences of a non-flat geometry is given on the sphere, where the shortest path between two points – a geodesic – is along a great circle. READ MORE