Sökning: "spectral decomposition"

Visar resultat 1 - 5 av 52 avhandlingar innehållade orden spectral decomposition.

  1. 1. Spectral Image Processing with Applications in Biotechnology and Pathology

    Författare :Milan Gavrilovic; Carolina Wählby; Ewert Bengtsson; Ingrid Carlbom; Robert Murphy; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; color theory; light microscopy; spectral imaging; image analysis; digital image processing; mathematical modeling; estimation; noise models; spectral decomposition; color decomposition; colocalization; cross-talk; autofluorescence; tissue separation; prostate cancer; biomedical applications; molecular biotechnology; histopathology; Computerized Image Processing; Datoriserad bildbehandling;

    Sammanfattning : Color theory was first formalized in the seventeenth century by Isaac Newton just a couple of decades after the first microscope was built. But it was not until the twentieth century that technological advances led to the integration of color theory, optical spectroscopy and light microscopy through spectral image processing. LÄS MER

  2. 2. Directional Decomposition in Anisotropic Heterogeneous Media for Acoustic and Electromagnetic Fields

    Författare :B. Lars G. Jonsson; KTH; []
    Nyckelord :directional wave-field decomposition; wave splitting; spectral reduction; aourstic anisotropy; electromagnetic anisotropy; generalized eigenvalue problem;

    Sammanfattning : Directional wave-field decomposition for heterogeneousanisotropic media with in-stantaneous response is establishedfor both the acoustic and the electromagnetic equations.We derive a sufficient condition for ellipticity of thesystem's matrix in the Laplace domain and show that theconstruction of the splitting matrix via a Dunford-Taylorintegral over the resolvent of the non-compact, non-normalsystem's matrix is well de ned. LÄS MER

  3. 3. Spectral Computed Tomography with a Photon-Counting Silicon-Strip Detector

    Författare :Mats Persson; Mats Danielsson; Hans Bornefalk; Jiang Hsieh; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; Photon-counting; silicon-strip detector; spectral computed tomography; ring artifacts; fluence rate; basis material decomposition; sub-pixel information; Physics; Fysik;

    Sammanfattning : Computed tomography (CT) is a widely used medical imaging modality. By rotating an x-ray tube and an x-ray detector around the patient, a CT scanner is able to measure the x-ray transmission from all directions and form an image of the patient’s interior. LÄS MER

  4. 4. Quantification and Maximization of Performance Measures for Photon Counting Spectral Computed Tomography

    Författare :Moa Yveborg; Hans Bornefalk; Franz Pfeiffer; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; spectral computed tomography; silicon detector; detectability index; photon counting; Hotelling SDNR; material basis decomposition;

    Sammanfattning : During my time as a PhD student at the Physics of Medical Imaging group at KTH, I have taken part in the work of developing a photon counting spectrally resolved silicon detector for clinical computed tomography. This work has largely motivated the direction of my research, and is the main reason for my focus on certain issues. LÄS MER

  5. 5. Spectral-element simulations of turbulent wall-bounded flows including transition and separation

    Författare :Johan Malm; Dan Henningson; Philipp Schlatter; Suad Jakirlic; KTH; []
    Nyckelord :spectral-element method; direct numerical simulation DNS ; large-eddy simulation LES ; turbulence; transition; over-integration; three-dimensional separation; massively parallel simulations; proper orthogonal decomposition POD ; Koopman modes; vorticity stretching; coherence; SRA - E-Science SeRC ; SRA - E-vetenskap SeRC ;

    Sammanfattning : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. LÄS MER