Sökning: "Two-dimensional ultrasound"

Visar resultat 16 - 20 av 25 avhandlingar innehållade orden Two-dimensional ultrasound.

  1. 16. 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. 17. Modelling of ultrasonic testing for cracks near a non-planar surface

    Författare :Jonathan Westlund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultrasonics; BIEM; Elastic waves; Nondestructive testing; Crack; BEM.;

    Sammanfattning : Nondestructive testing using ultrasound has important applications in e.g. the nuclear power and aerospace industries, where it is used to inspect safety-critical parts for flaws. LÄS MER

  4. 18. Manifolds in Image Science and Visualization

    Författare :Anders Brun; Hans Knutsson; Magnus Herberthson; Carl-Fredrik Westin; Roland Wilson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; manifold learning; image analysis; signal processing; diffusion tensor mri; Medical engineering; Medicinsk teknik;

    Sammanfattning : A Riemannian manifold is a mathematical concept that generalizes curved surfaces to higher dimensions, giving a precise meaning to concepts like angle, length, area, volume and curvature. A glimpse of the consequences of a non-flat geometry is given on the sphere, where the shortest path between two points – a geodesic – is along a great circle. LÄS MER

  5. 19. Spindle vibration and sound field measurement using optical vibrometry

    Författare :Kourosh Tatar; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : Mechanical systems often produce a considerable amount of vibration and noise. To be able to obtain a complete picture of the dynamic behaviour of these systems, vibration and sound measurements are of significant importance. Optical metrology is well-suited for non-intrusive measurements on complex objects. LÄS MER

  7. 20. Molecular aspects of post-Chornobyl and sporadic papillary thyroid carcinoma

    Författare :Andrii Dinets; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :papillary thyroid carcinoma;

    Sammanfattning : Papillary thyroid carcinoma (PTC) exhibits various molecular abnormalities, both when sporadic and radiation-related. PTC is still diagnosed in adult individuals who were younger than 18 years at the time of the Chornobyl accident in 1986 and lived within the contaminated area. LÄS MER