Essays about: "Expectation-maximization"

Showing result 1 - 5 of 38 essays containing the word Expectation-maximization.

  1. 1. A study about Active Semi-Supervised Learning for Generative Models

    University essay from Linköpings universitet/Institutionen för datavetenskap

    Author : Elisio Fernandes de Almeida Quintino; [2023]
    Keywords : Semi-Supervised Learning; Active Learning; Generative Models; Mixture Models; Semi-Övervakad Inlärning; Aktiv Inlärning; Generativa Modeller; Mixturmodeller;

    Abstract : In many relevant scenarios, there is an imbalance between abundant unlabeled data and scarce labeled data to train predictive models. Semi-Supervised Learning and Active Learning are two distinct approaches to deal with this issue. READ MORE

  3. 2. Effects of reconstruction parameters on the image quality and quantification of PET images from PET/MRI and PET/CT systems

    University essay from

    Author : Ali Amena Hussain; [2022-03-09]
    Keywords : Medical physics; PET CT; PET MRI; OSEM; BPL; NEMA IQ; positron emission tomography; magnetic resonance imaging; computed tomography; ordered Subset Expectation Maximization; The Bayesian Penalized Likelihood;

    Abstract : Aim: To study how reconstruction parameters affect the positron emission tomography (PET) image quality and quantitative results for the different lesion to background radioactivity ratios in three different PET systems. Introduction: Multimodality imaging that combines magnetic resonance imaging (MRI) or computed tomography (CT) with a PET system can produce medical images containing both functional and anatomical information. READ MORE

  4. 3. Spatiotemporal PET reconstruction with Learned Registration

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Pierre Meyrat; [2022]
    Keywords : PET; Tomographic reconstruction; Deep Learning; MLEM; PET; Tomografisk rekonstruktion; Deep Learning; MLEM;

    Abstract : Because of the long acquisition time of Positron Emission Tomography scanners, the reconstructed images are blurred by motion. We hereby propose a novel motion-correction maximum-likelihood expectation-maximization algorithm integrating 3D movements between the different gates estimated by a neural network trained on synthetic data with contrast invariance. READ MORE

  5. 4. Automatic magnetic resonance brain volume measurements to assess the effect of minimised blood sample extraction on brain development in extremely preterm infants

    University essay from Lunds universitet/Läkarutbildningen

    Author : Hickmat Hamie; [2021]
    Keywords : Magnetic resonance imaging; Brain development; Prematurity; Medicine and Health Sciences;

    Abstract : Aim: To evaluate a pipeline for automatic MRI brain segmentation and volumetric tissue structure quantification in a cohort of extremely preterm infants. Methods: 13 extremely preterm neonates underwent MRI-scanning at a term equivalent age. Seven of these subjects had suitable MRI sequences and were analyzed in the pipeline. READ MORE

  6. 5. Grouping Similar Bug Reports from Crash Dumps with Unsupervised Learning

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Sara Vestergren; [2021]
    Keywords : Unsupervised Learning; Bug Report; Duplicate Detection; Clustering; Software Crash; Oövervakad Inlärning; Felrapport; Dublett-detektering; Klustring; Mjukvarukrasch;

    Abstract : Quality software usually means high reliability, which in turn has two main components; the software should provide correctness, which means it should perform the specified task, and robustness in the sense that it should be able to manage unexpected situations. In other words, reliable systems are systems without bugs. READ MORE