Sökning: "Acoustic Doppler"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden Acoustic Doppler.

  1. 1. A Novel Signal Model and Estimation Method for Acoustic Doppler Current Meters

    Författare :Thomas L Lagö; Teknisk akustik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doppler Profiler; Acoustic Doppler; Gaussian Backscattering Model; ADCM; ADCP; The Symmiktos Method; Estimation; Doppler; Current; MPCA.; Technological sciences; Teknik; Electromagnetism; optics; acoustics; Elektromagnetism; optik; akustik;

    Sammanfattning : This thesis deals with the process of estimating underwater current from the backscattering signal transmitted from an ultrasonic transducer. The narrowband sinusoidal burst signal is Doppler-shifted due to the current, and this information is converted into current. LÄS MER

  3. 2. An Acoustic Doppler Current Meter, Methods and Principles

    Författare :Thomas L Lagö; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : .... LÄS MER

  4. 3. On Health-Related Quality of Life and Diagnostic Improvements in Rhinosinusitis

    Författare :Pernilla Sahlstrand Johnson; allergi och livskvalitet Laryngoesofagologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; rhinosinusitis; nasal polyps; health-related quality of life; absenteeism; Doppler ultrasound; acoustic streaming; attenuation;

    Sammanfattning : Rhinosinusitis is defined as an inflammatory process involving the mucosa of the nose and one or more of the paranasal sinuses. The aims of the work presented in this thesis were to investigate the degree to which rhinosinusitis affects the health-related quality of life (HRQOL), and to determine whether the diagnosis of this condition can be improved using Doppler ultrasound. LÄS MER

  5. 4. On perfusion estimation using ultrasound

    Författare :Tomas Jansson; Avdelningen för Biomedicinsk teknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Instrumentation technology; Speckle; Artifacts; Perfusion; Ultrasound; Doppler; Mät- och instrumenteringsteknik;

    Sammanfattning : This thesis has the main focus on ways to improve the blood perfusion estimate, as obtained from a continuous wave Doppler system. Earlier studies have shown large temporal variations in the detected perfusion estimate, due to speckle. LÄS MER

  7. 5. On the Design of Noncoherent Acoustic Underwater Communication

    Författare :Viktor Lidström; Magnus Lundberg Nordenvaad; Peter Sigray; Jacob Kuttenkeuler; Paul van Walree; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noncoherent; acoustic underwater communication; link adaptation; adaptive networks; ickecoherent; akustisk undervattenskommunikation; länkadaption; adaptiva nätverk; Farkostteknik; Vehicle and Maritime Engineering;

    Sammanfattning : The underwater domain is an environment hostile to humans due to the hydrostatic pressure that rapidly increases with water depth, which has led to underwater robotics becoming an emerging technological field with many commercial-, environmental-, and security-related applications. A major challenge to untethered autonomous underwater vehicles (AUVs) is communicating robot-to-robot and robot-to-topside operator since it must, in most cases, be done acoustically. LÄS MER