Sökning: "expectation-maximum"

Hittade 2 uppsatser innehållade ordet expectation-maximum.

  1. 1. Quantification of cerebral blood flow with 15O-water PET : A comparison study between PET/CT and PET/MR and two different blood sampling instruments

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik; Umeå universitet/Diagnostisk radiologi

    Författare :Amanda Eriksson; [2021]
    Nyckelord :Cerebral Blood Flow; CBF; oxygen-15-labelled water; PET CT; PET MR; Quantification of CBF; Image Derived Input Function; IDIF; Blood Sampled Input Function; BSIF; Arterial Input Function; AIF; Tracer Kinetic Modelling; Single Tissue Compartmental Model; 1TCM;

    Sammanfattning : Cerebral blood flow quantification is a vital diagnostic tool for disease monitoring and used for diagnosing a variation of pathological conditions. The human brain requires roughly about 20 % of the total cardiac output to sustain normal functioning, hence the perfusion of blood is an important factor to deliver oxygenated blood. LÄS MER

  3. 2. Comparing unsupervised clustering algorithms to locate uncommon user behavior in public travel data : A comparison between the K-Means and Gaussian Mixture Model algorithms

    Kandidat-uppsats, Jönköping University/JTH, Datateknik och informatik

    Författare :Anton Andrésen; Adam Håkansson; [2020]
    Nyckelord :Machine learning; clustering; K-Means; Gaussian Mixture Model; expectation-maximum; data analysis; public transport; silhouette analysis; outliers; outlier detection; data; algorithms; experiment;

    Sammanfattning : Clustering machine learning algorithms have existed for a long time and there are a multitude of variations of them available to implement. Each of them has its advantages and disadvantages, which makes it challenging to select one for a particular problem and application. LÄS MER