Search for dissertations about: "Ultrasonic array imaging"

Found 5 swedish dissertations containing the words Ultrasonic array imaging.

2. 1. Time-domain Reconstruction Methods for Ultrasonic Array Imaging : A Statistical Approach

   Author : Fredrik Lingvall; Tadeusz Stepinski; Karl-Jörg Langenberg; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Ultrasonic array imaging; synthetic aperture imaging; maximum a posteriori estimation; linear minimum mean squared error estimation; SAFT; Bayesian image reconstruction; Signalbehandling; Signal processing; Signalbehandling; Signal Processing; signalbehandling;

   Abstract : This thesis is concerned with reconstruction techniques for ultrasonic array imaging based on a statistical approach. The reconstruction problem is posed as the estimation of an image consisting of scattering strengths. READ MORE

4. 2. Ultrasonic Arrays for Sensing and Beamforming of Lamb Waves

   Author : Marcus Engholm; Tadeusz Stepinski; Paul D. Wilcox; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; imaging; array processing; guided waves; Lamb waves; dispersive waves; multi-modal waves; spatial filtering; mode suppression; resonant ultrasound; transducer design; direction of arrival estimation; adaptive beamforming; Signal processing; Signalbehandling; Electronic measurement and instrumentation; Elektronisk mät- och apparatteknik;

   Abstract : Non-destructive testing (NDT) techniques are critical to ensure integrity and safety of engineered structures. Structural health monitoring (SHM) is considered as the next step in the field enabling continuous monitoring of structures. READ MORE

5. 3. Experimental Validation and Applications of a Phased Array Ultrasonic Testing Probe Model

   Author : Xiangyu Lei; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Simulations; Applications; Nondestructive testing NDT ; Phased array ultrasonic testing PAUT ; Experiments;

   Abstract : New manufacturing technologies are developed to facilitate flexible product designs and production processes. However, the quality of the final products should not be compromised. The assessment of product quality and integrity lies on various inspection methods. READ MORE

6. 4. Ultrasonic characterization of materials and multiphase flows

   Author : Johan Carlson; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

   Abstract : This thesis deals with three different applications of ultrasound measurement technology. In process industries like the mining industry, the oil and gas industry, and the paper pulp industry, multiphase flows play an important role. READ MORE

7. 5. Lamb wave evaluation of concrete plates

   Author : Oskar Tofeldt; Teknisk geologi; []
   Keywords : Lamb waves; guided waves; impact-echo; concrete; non-destructive evaluation;

   Abstract : This thesis is about the application of Lamb waves for non-destructive evaluation of plate-like concrete structures under one-sided access test condition using a portable equipment consisting of an accelerometer and impact hammer. With this type of equipment and based on array signal processing, the impact-echo (IE) method can be extended with measurements of surface waves; this extension allows an evaluation with Lamb waves. READ MORE