Sökning: "ill posed problem"

Visar resultat 1 - 5 av 17 uppsatser innehållade orden ill posed problem.

  1. 1. Limited angle reconstruction for 2D CT based on machine learning

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Eric Oldgren; Knut Salomonsson; [2023]
    Nyckelord :CT; computed tomography; limited angle; machine learning; limited data; ill posed problem; inverse problem;

    Sammanfattning : The aim of this report is to study how machine learning can be used to reconstruct 2 dimensional computed tomography images from limited angle data. This could be used in a variety of applications where either the space or timeavailable for the CT scan limits the acquired data.In this study, three different types of models are considered. LÄS MER

  3. 2. 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

  4. 3. Virtual Staining of Blood Cells using Point Light Source Illumination and Deep Learning

    Master-uppsats, Lunds universitet/Matematik LTH

    Författare :Joel Wulff; [2022]
    Nyckelord :Deep learning; virtual staining; blood; cells; GANs; Generative adversarial networks; CNNs; convolutional neural networks; ESRGAN; Unet; digital microscopy; Mathematics and Statistics;

    Sammanfattning : Blood tests are an important part of modern medicine, and are essentially always stained using chemical colorization methods before analysis by computational or manual methods. The staining process allows different parts of blood cells to be discerned that would be unnoticeable in unstained blood. LÄS MER

  5. 4. 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

  7. 5. On Robust Forecast Combinations With Applications to Automated Forecasting

    Master-uppsats, Uppsala universitet/Statistiska institutionen

    Författare :Arvid Nybrant; [2021]
    Nyckelord :Forecast Combinations; Model Uncertainty; Predictive Failure; Forecast Risk;

    Sammanfattning : Combining forecasts have been proven as one of the most successful methods to improve predictive performance. However, while there often is a focus on theoretically optimal methods, this is an ill-posed issue in practice where the problem of robustness is of more empirical relevance. LÄS MER