Essays about: "expectation maximization"

Showing result 11 - 15 of 41 essays containing the words expectation maximization.

  1. 11. Implementing and Evaluating sparsification methods in probabilistic networks

    University essay from Uppsala universitet/Institutionen för informationsteknologi

    Author : Oskar Dahlin; [2020]
    Keywords : ;

    Abstract : Most queries on probabilistic networks assume a possible world semantic, which causes an exponential increase in execution time. Deterministic networks can apply sparsification methods to reduce their sizes while preserving some structural properties, but there have not been any equivalent methods for probabilistic networks until recently. READ MORE

  3. 12. Deep Learning for PET Imaging : From Denoising to Learned Primal-Dual Reconstruction

    University essay from KTH/Skolan för kemi, bioteknologi och hälsa (CBH)

    Author : Alessandro Guazzo; [2020]
    Keywords : PET Deep Learning Reconstruction Denoising;

    Abstract : PET imaging is a key tool in the fight against cancer. One of the main issues of PET imaging is the high level of noise that characterizes the reconstructed image, during this project we implemented several algorithms with the aim of improving the reconstruction of PET images exploiting the power of Neural Networks. READ MORE

  4. 13. Joint Estimation and Calibration for Motion Sensor

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

    Author : Peng Liu; [2020]
    Keywords : State space model; accelerometer array; parameter estimation; Maximum Likelihood; Expectation Maximization; Gradient Descent; ill-conditioned matrix.; tillståndsmodell; accelerometerarray; parameterskattning; maximimetoden; väntevärdesmaximering; gradientsökning; illakonditionerade matriser.;

    Abstract : In the thesis, a calibration method for positions of each accelerometer in an Inertial Sensor Array (IMU) sensor array is designed and implemented. In order to model the motion of the sensor array in the real world, we build up a state space model. Based on the model we use, the problem is to estimate the parameters within the state space model. READ MORE

  5. 14. Estimating Risk Using Stochastic Volatility Models and Particle Stochastic Approximation Expectation Maximization

    University essay from Lunds universitet/Matematisk statistik

    Author : Henrik Kragh; [2020]
    Keywords : Mathematics and Statistics;

    Abstract : In this thesis several stochastic volatility models are presented and used to estimate the risk of a collection of Swedish stocks, as well as of a portfolio consisting of said stocks. Model parameters are estimated using the PSAEM algorithm. READ MORE

  6. 15. Improving the speed and quality of an Adverse Event cluster analysis with Stepwise Expectation Maximization and Community Detection

    University essay from Uppsala universitet/Institutionen för medicinska vetenskaper

    Author : Nils Erlanson; [2020]
    Keywords : Adverse Drug Reactions; Pharmacovigilance; Cluster Analysis; Stepwise Expectation Maximization; Community Detection; Topic Modelling;

    Abstract : Adverse drug reactions are unwanted effects alongside the intended benefit of a drug and might be responsible for 3-7\% of hospitalizations. Finding such reactions is partly done by analysing individual case safety reports (ICSR) of adverse events. The reports consist of categorical terms that describe the event. READ MORE