Sökning: "ultrasonic measurement"

Visar resultat 1 - 5 av 45 avhandlingar innehållade orden ultrasonic measurement.

  1. 1. Ultrasonic measurement principles : modeling, identification, and parameter estimation

    Författare :Jesper Martinsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industrial Electronics; Industriell elektronik;

    Sammanfattning : This thesis presents contributions within the fields of ultrasonic modeling and measurement technology, with focus on solutions to difficult modeling and measurement problems. The work is divided into two categories: 1) processing of measurements obtained under non-ideal conditions, such as unsynchronized, distorted, and superimposed signals; 2) estimating acoustic models and parameters from materials, fluids, fluid mixtures, and thin-layered structures. LÄS MER

  3. 2. Non-destructive measurement of near-surface cracks in railheads : with focus on ultrasonic inspections

    Författare :Rayendra Anandika; Jan Lundberg; Paul Wilcox; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail inspection; phased array; ultrasonic testing; eddy current testing; surface cracks; non-destructive testing; NDT; railway; condition monitoring; Drift och underhållsteknik; Operation and Maintenance;

    Sammanfattning : Near-surface cracks in railhead that caused by rolling contact fatigue (RCF) is one of a kind rail defects that degrade rail track quality. Dependent on the trail load, the cracks can reach to severe level quickly. LÄS MER

  4. 3. An ultrasonic density measurement technique : performance, thermal effects, experimental validations, and modeling

    Författare :Jan van Deventer; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

    Sammanfattning : This licentiate thesis addresses the idea of measurement of the density of liquids using sound. The thesis can be dived into three sections: 1. An introduction that presents the need for the research and its future application into an ultrasonic mass flow meter. 2. LÄS MER

  5. 4. Boundary Detection in Cardiovascular Ultrasonic Images Based on Multiscale Dynamic Programming

    Författare :Quan Liang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiscale dynamic programming; artery measurement; cardiac measurement; edge-preserving smoothing; ultrasonic imaging; boundary detection;

    Sammanfattning : Non-invasive ultrasonic imaging is widely used in cardiovascular studies as well as clinical diagnostics. This is due to its non-invasiveness, low cost and easy operation. However, ultrasonic images are noisy and present artifacts, speckles, and echo dropouts. LÄS MER

  7. 5. Automated ultrasonic measurement of human arteries by a multiscale dynamic programming approach

    Författare :Quan Liang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; atery measurement; ultrasonic imaging; multiscale dynamic programming; boundary detection;

    Sammanfattning : .... LÄS MER