Search for dissertations about: "singular points"

Showing result 1 - 5 of 25 swedish dissertations containing the words singular points.

2. 1. Singular Ginzburg-Landau Vortices

   Author : Mats Aigner; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; singularities; Ginzburg-Landau; vortices; Matematik;

   Abstract : In this thesis we study the critical Ginzburg-Landau action, defined on fields in the plane which are allowed to have a finite number of singularities. We show that a topological invariant, the degree, can be defined under the assumption of finite action only. READ MORE

4. 2. Counting rational points on genus one curves

   Author : Manh Hung Tran; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Diophantine equations; rational points; Elliptic curves; genus; descent; determinant method; cubic and quartic curves; genus;

   Abstract : This thesis contains two papers dealing with counting problems for curves of genus one. We obtain uniform upper bounds for the number of rational points of bounded height on such curves. The main tools to study these problems are descent and various refined versions of Heath-Brown’s p-adic determinant method. READ MORE

5. 3. Symmetry Filters Applied to Fingerprints : Representation, Feature extraction and Registration

   Author : Kenneth Nilsson; Högskolan i Halmstad; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fingerprint recognition; symmetry filters; orientation field; multiscale filtering; singular points; orientation radiograms; registration; multiexpert; TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : A common framework for feature extraction in fingerprints is proposed by use of certain symmetries. The proposal includes representation, filters, and filtering techniques for common features including minutiae points, singular points and the ridge and valley patterns. READ MORE

6. 4. Simple Layer Potentials on Lipschitz Surfaces: An Asymptotic Approach

   Author : Johan Thim; Vladimir Kozlov; Bengt Ove Turesson; Martin Costabel; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Singular integrals; Lipschitz surfaces; Mathematical analysis; Analys;

   Abstract : This work is devoted to the equationwhere S is the graph of a Lipschitz function φ on RN with small Lipschitz constant, and dS is the Euclidian surface measure. The integral in the left-hand side is referred to as a simple layer potential and f is a given function. READ MORE

7. 5. Generalized Hebbian Algorithm for Dimensionality Reduction in Natural Language Processing

   Author : Genevieve Gorrell; Arne Jönsson; Robin Cooper; Alexander Rudnicky; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Generalized Hebbian Algorithm; Language Modelling; Singular Value Decomposition; Eigen Decomposition; Latent Semantic Analysis; Vector Space Models; Computational linguistics; Datorlingvistik;

   Abstract : The current surge of interest in search and comparison tasks in natural language processing has brought with it a focus on vector space approaches and vector space dimensionality reduction techniques. Presenting data as points in hyperspace provides opportunities to use a variety of welldeveloped tools pertinent to this representation. READ MORE