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Visar resultat 1 - 5 av 17 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Scan Statistics for Space-Time Cluster Detection

    Författare :Benjamin Allévius; Martin Sköld; Michael Höhle; Paula Moraga-Serrano; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Scan statistics are used by public health agencies to detect and localize disease outbreaks. This thesis provides an overview of scan statistics in the context of prospective disease surveillance and outbreak detection, presents a novel scan statistic to deal with the type of zero-abundant data that is often encountered in these settings, and—perhaps most importantly—implements this and other scan statistics in a freely available and open source R package. LÄS MER

  3. 2. Topics in multifractal measures, nonparametrics and biostatistics

    Författare :Attila Frigyesi; Anestesiologi och intensivvård; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; confidence interval; mixed effects; Statistics; operations research; programming; actuarial mathematics; Statistik; operationsanalys; programmering; aktuariematematik; operational model of pharmacological agonism; concentration-response curves; dose-response curves; ventilation perfusion scintigraphy; V Q-scan; pulmonary embolism; automated method; box counting; correlation dimension; Hentschel-Procaccia dimension; Rényi dimension; generalized dimensions; fractal dimension estimation; dimension spectrum; multifractal measures; kernel density estimates; absolute continuity; singular distribution functions;

    Sammanfattning : This thesis consists of four papers. The first two papers, which comprise the main part of the thesis, deal with an unexpected connection between kernel density estimators and dimension spectra for multifractal measures. LÄS MER

  4. 3. The PET sampling puzzle : intelligent data sampling methods for positron emission tomography

    Författare :Klara Leffler; Jun Yu; Ida Häggström; Zhiyong Zhou; Saikat Chatterjee; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; sparse signal processing; compressed sensing; Poisson denoising; positron emission tomography PET ; sinogram denoising; sinogram inpainting; deep learning; matematisk statistik; Mathematical Statistics;

    Sammanfattning : Much like a backwards computed Sudoku puzzle, starting from the completed number grid and working ones way down to a partially completed grid without damaging the route back to the full unique solution, this thesis tackles the challenges behind setting up a number puzzle in the context of biomedical imaging. By leveraging sparse signal processing theory, we study the means of practical undersampling of positron emission tomography (PET) measurements, an imaging modality in nuclear medicine that visualises functional processes within the body using radioactive tracers. LÄS MER

  5. 4. Quantitative methods for diffusion measurements in fluorescence microscopy

    Författare :Marco Longfils; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cross-validation.; single particle tracking; Confocal laser scanning microscopy; raster scan; correlation spectroscopy; mixture models; diffusion;

    Sammanfattning : In this work, statistical methods are developed for mapping mass transport locally based on images collected using a confocal laser scanning microscope. Besides presenting raster image correlation spectroscopy as an established method in fluorescence microscopy, we introduce a single particle tracking method which takes advantage of the raster scanning of the image in a confocal microscope. LÄS MER

  7. 5. Raster Image Analysis of Diffusion via Single Particle Methods

    Författare :Marco Longfils; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; single particle tracking; raster scan; confocal laser scanning microscopy; image correlation spectroscopy; raster scan;

    Sammanfattning : Soft biomaterials are widely used in many application areas, spanning from packaging materials to pharmaceuticals. To enhance their functionalities, understanding the interplay between microstructure and mass transport properties in these materials is fundamental. LÄS MER