Essays about: "ill-posed"

Showing result 1 - 5 of 21 essays containing the word ill-posed.

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

    University essay from KTH/Skolan för teknikvetenskap (SCI)

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

    Abstract : 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. READ MORE

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

    University essay from Lunds universitet/Matematik LTH

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

    Abstract : 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. READ MORE

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

    University essay from Linköpings universitet/Analys och didaktik; Linköpings universitet/Tekniska fakulteten

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

    Abstract : 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. READ MORE

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

    University essay from Uppsala universitet/Statistiska institutionen

    Author : Arvid Nybrant; [2021]
    Keywords : Forecast Combinations; Model Uncertainty; Predictive Failure; Forecast Risk;

    Abstract : 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. READ MORE

  6. 5. Upscaling of pictures using convolutional neural networks

    University essay from Uppsala universitet/Avdelningen för visuell information och interaktion

    Author : Caspar Norée Palm; Hugo Granström; [2021]
    Keywords : super; resolution; convolutional; neural; networks; upscaling; pictures; psnr; u-net; unet;

    Abstract : The task of upscaling pictures is very ill-posed since it requires the creation of novel data. Any algorithm or model trying to perform this task will have to interpolate and guess the missing pixels in the pictures. Classical algorithms usually result in blurred or pixelated interpolations, especially visible around sharp edges. READ MORE