Sökning: "vector tomography"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden vector tomography.

  1. 1. Studies of vector tomography

    Författare :Kent Stråhlén; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Doppler tomography; Doppler Radon transform; local tomography; vectorial k-plane transform; vectorial Radon transform; k-plane transform; Radon transform; tomography; vector tomography; Mathematics; Matematik;

    Sammanfattning : The motivation to study the kind of problems appearing in this thesis has been ultrasound measurements of flows, from which velocity spectra along lines can be determined. These velocity spectra can mathematically be described by a new non-linear transform, here called the Doppler Spectral Transform (DST). LÄS MER

  3. 2. Experimental verification of tomographic measurement methods in ultrasound

    Författare :Monica Almqvist; Avdelningen för Biomedicinsk teknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; airborne.; high resolution; characterization; tomography; light diffraction; doppler; ultrasound; vector tomography; Instrumentation technology; Mät- och instrumenteringsteknik;

    Sammanfattning : This thesis describes two different measurement methods applied to ultrasound. The first method, Ultrasound doppler vector tomography, uses ultrasound to measure blood flow and the second method, Light diffraction tomography, measures the pressure field in an ultrasound beam with laser light. LÄS MER

  4. 3. Development of Automated Algorithms for Epicardial Adipose Tissue Analysis in Computed Tomography and their Application in Population Based Research

    Författare :David Molnar; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Epicardial adipose tissue; Artificial intelligence; Automatic analysis; Computed tomography; Coronary atherosclerosis; Pre-diabetes; Vector electrocardiography;

    Sammanfattning : The epicardial adipose tissue (EAT), which surrounds the heart and is separated from other tissues only by the thin layers of the pericardium, has enjoyed intense research for the past decades. Increased inflammatory activity in the EAT in coronary artery disease has, together with associated volumetric expansion of the EAT and changes in its radiodensity supported theories that the EAT might play a role in the pathogenesis of coronary atherosclerosis or mirror its progression better than traditional risk factors. LÄS MER

  5. 4. Ultra-Wideband Time Domain Measurement Systems for Microwave Tomography

    Författare :Xuezhi Zeng; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time DomainMeasurement; Ultra-Wideband; EquivalentTime Sampling; Real Time Sampling; Microwave Tomography; Measurement Error; Frequency Domain Measurement;

    Sammanfattning : As a potential imaging modality for biomedical applications, microwave tomography has attracted a lot of interests in recent years. With microwave tomography, microwave signals are transmitted into the biological tissues and the scattered fields are recorded. LÄS MER

  7. 5. Temporal Characteristics of Boreal Forest Radar Measurements

    Författare :Albert Monteith; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; antenna array; Synthetic aperture radar; temporal coherence; tomography; backscatter; remote sensing;

    Sammanfattning : Radar observations of forests are sensitive to seasonal changes, meteorological variables and variations in soil and tree water content. These phenomena cause temporal variations in radar measurements, limiting the accuracy of tree height and biomass estimates using radar data. LÄS MER