Sökning: "inverse problems"

Visar resultat 6 - 10 av 178 avhandlingar innehållade orden inverse problems.

  1. 6. Inverse Problems for Graph Laplacians

    Författare :Marlena Nowaczyk; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; Laplace operator; Trace formula; Quantum graphs;

    Sammanfattning : This thesis is devoted to inverse spectral problems for Laplace operators on metric graphs, and it is based on the following papers: Paper I - P. Kurasov and M. Nowaczyk 2005 Inverse spectral problem for quantum graphs J. Phys. LÄS MER

  3. 7. Inverse Problems in Tomography and Fast Methods for Singular Convolutions

    Författare :Fredrik Andersson; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik; Unequally spaced FFT; Integral transforms; Singular integrals; Lippmann?Schwinger equation; Helmholtz equation; Inverse problems; Fast Gauss transform; Fast summation; Convolution; Radon transform; Tomography;

    Sammanfattning : There are two, partially interlaced, themes treated in this thesis; inverse problems of tomographic type and fast and accurate methods for the application of convolution operators. Regarding the first theme, the inverse problem of Doppler tomography is considered and the Doppler moment transform is introduced for that purpose. LÄS MER

  4. 8. Non-linear inverse geothermal problems

    Författare :Dennis Wokiyi; Vladimir Kozlov; Fredrik Berntsson; Mårten Gulliksson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The inverse geothermal problem consist of estimating the temperature distribution below the earth’s surface using temperature and heat-flux measurements on the earth’s surface. The problem is important since temperature governs a variety of the geological processes including formation of magmas, minerals, fosil fuels and also deformation of rocks. LÄS MER

  5. 9. Multidimensional inverse problems in imaging and identification using low-complexity models, optimal mass transport, and machine learning

    Författare :Axel Ringh; Johan Karlsson; Rodolphe Sepulchre; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inverse problems; convex optimization; variational regularization; trigonometric moment problems; optimal mass transport; computed tomography; machine learning; analytic interpolation; delay systems; Inversa problem; konvex optimering; variationell regularisering; trigonometriska momentproblem; optimal masstransport; datortomografi; maskininlärning; analytisk interpolation; system med tidsfördröjning; Mathematics; Matematik;

    Sammanfattning : This thesis, which mainly consists of six appended papers, primarily considers a number of inverse problems in imaging and system identification.In particular, the first two papers generalize results for the rational covariance extension problem from one to higher dimensions. LÄS MER

  7. 10. Inverse and optimization problems in electromagnetics -- a finite-element method perspective

    Författare :JOHAN WINGES; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave measurements; computational electromagnetics; finite element method; optimization; inductive power transfer; compressed sensing; wireless power; brick-tetrahedron hybrid; parameter estimation; inverse problems;

    Sammanfattning : In this thesis, a selection of inverse and optimization problems are studied where the finite element method (FEM) serves as a comprehensive tool to solve electromagnetic field problems that lack an analytic solution. The inverse problems are typically formulated in terms of an optimization problem where the misfit between a measurement and the corresponding result of a computational model is minimized. LÄS MER