Sökning: "ill-posed problems"

Visar resultat 1 - 5 av 6 uppsatser innehållade orden ill-posed problems.

  1. 1. Variationell Regularisering av Inversproblem med Till¨ampning inom Skiktr¨ontgen

    Kandidat-uppsats, Göteborgs universitet/Institutionen för matematiska vetenskaper

    Författare :Sara Sofie Nilsson; Louise Christensson; Oskar Pauli; Gustav Svensson; [2022-07-05]
    Nyckelord :;

    Sammanfattning : The aim of this study was to solve ill-posed inverse problems when reconstructing data by using variational regularization theory. This problem was solved using MATLAB. Data was simulated from MATLAB’s 256×256 Shepp-Logan phantom, which also acted as our reference image. LÄS MER

  3. 2. Regularizing An Ill-Posed Problem with Tikhonov’s Regularization

    Kandidat-uppsats, Linköpings universitet/Analys och didaktik; Linköpings universitet/Tekniska fakulteten

    Författare :Herman Singh; [2022]
    Nyckelord :Inverse problem; Ill-posed problems; Tikhonov’s regularization; Fourier series; Helmholtz equation;

    Sammanfattning : This thesis presents how Tikhonov’s regularization can be used to solve an inverse problem of Helmholtz equation inside of a rectangle. The rectangle will be met with both Neumann and Dirichlet boundary conditions. A linear operator containing a Fourier series will be derived from the Helmholtz equation. LÄS MER

  4. 3. Towards Identification of Effective Parameters in Heterogeneous Media

    Master-uppsats,

    Författare :David Johansson; [2020]
    Nyckelord :parameter identification; multiscale modelling; homogenization theory; partial differential equations; inverse modelling;

    Sammanfattning : In this thesis we study a parameter identification problem for a stationary diffusion equation posed in heterogeneous media. This problem is closely related to the Calderón problem with anisotropic conductivities. The anisotropic case is particularly difficult and is ill-posed both in regards to uniqueness of solution and stability on the data. LÄS MER

  5. 4. Solving ill-posed problems with mollification and an application in biometrics

    Kandidat-uppsats, Linköpings universitet/Matematik och tillämpad matematik; Linköpings universitet/Tekniska fakulteten

    Författare :Emma Lindgren; [2018]
    Nyckelord :Mollification; regularization; ill-posed problems; biometrics; blood vessel;

    Sammanfattning : This is a thesis about how mollification can be used as a regularization method to reduce noise in ill-posed problems in order to make them well-posed. Ill-posed problems are problems where noise get magnified during the solution process. An example of this is how measurement errors increases with differentiation. LÄS MER

  7. 5. Parameter identification in a mathematical model of HIV infection with drug therapy

    Magister-uppsats, Institutionen för matematiska vetenskaper

    Författare :Martin Eriksson; [2017-12-12]
    Nyckelord :;

    Sammanfattning : Parameter identification problems are frequently occurring within biomedical applications. These problems are often ill-posed, and thus challenging to solve numerically. LÄS MER