Sökning: "Bengt-ove Turesson"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Bengt-ove Turesson.
1. The Double Layer Potential Operator Through Functional Calculus
Sammanfattning : Layer potential operators associated to elliptic partial differential equations have been an object of investigation for more than a century, due to their contribution in the solution of boundary value problems through integral equations.In this Licentiate thesis we prove the boundedness of the double layer potential operator on the Hilbert space of square integrable functions on the boundary, associated to second order uniformly elliptic equations in divergence form in the upper half-space, with real, possibly non-symmetric, bounded measurable coefficients, that do not depend on the variable transversal to the boundary. LÄS MER
2. An alternating iterative procedure for the Cauchy problem for the Helmholtz equation
Sammanfattning : Let be a bounded domain in Rn with a Lipschitz boundary Г divided into two parts Г0 and Г1 which do not intersect one another and have a common Lipschitz boundary. We consider the following Cauchy problem for the Helmholtz equation:where k, the wave number, is a positive real constant, аv denotes the outward normal derivative, and f and g are specified Cauchy data on Г0. LÄS MER
3. Iterative Methods for Solving the Cauchy Problem for the Helmholtz Equation
Sammanfattning : The inverse problem of reconstructing the acoustic, or electromagnetic, field from inexact measurements on a part of the boundary of a domain is important in applications, for instance for detecting the source of acoustic noise. The governing equation for the applications we consider is the Helmholtz equation. LÄS MER
4. Pairs of projections on a Hilbert space:properties and generalized invertibility
Sammanfattning : This thesis is concerned with the problem of characterizing sums, differences, and products of two projections on a separable Hilbert space. Other objective is characterizing the Moore-Penrose and the Drazin inverse for pairs of operators. We use reasoning similar to one presented in the famous P. LÄS MER
5. Permanence of age-structured populations in a spatio-temporal variable environment
Sammanfattning : It is widely recognized that various biotic and abiotic factors cause changes in the size of a population and its age distribution. Population structure, intra-specific competition, temporal variability and spatial heterogeneity are identified as the most important factors that, alone or in combination, influence population dynamics. LÄS MER
