In this thesis, we proposed an innovation ideal that is employment of laser to extract finger feature, and constructed laser speckle recognition systems for this kind of feature. When projecting laser on the object surface, the speckle could be obtained to represent the characteristic of object surface by collecting scattered light. Two measurement of scattered light was adopted. First is laser signal recording the strength of scattered light when laser scan across the finger. The second is laser speckle image which is demonstrated when projecting the laser on the fingerprint and simultaneously collecting the scatter light by CCD. We proposed two recognition systems for laser signal and laser speckle. Besides, the proposed laser speckle fingerprint recognition system combines biometric detection, it can accurately distinguish biometric and non-biometric speckle. Experimental results demonstrate that proposed laser speckle recognition systems are feasible and with excellent ability of identity verification.

No description available.

The objective of this study is to apply digital image processing (DIP) techniques to optical coherence tomography (OCT) images and develop computer-based non-subjective quantitative analysis, which can be used as diagnostic aids in early detection of dental caries. This study first compares speckle reduction effects on raw OCT image data by implementing spatial-domain and transform-domain speckle filtering. Then region-based contour search and global thresholding techniques examine digital OCT images with possible lesions to identify and highlight the presence of features indicating early stage dental caries. The outputs of these processes, which explore the combination of image restoration and segmentation, can be used to distinguish lesion from normal tissue and determine the characteristics prior to, during, and following treatments. The combination of image processing and analysis techniques in this thesis shows potential of detecting early stage caries lesion successfully.

Coherent X-ray diffraction and X-ray Intensity Fluctuation Spectroscopy (XIFS) are ideal methods and techniques to perform measurements on the dynamics of fluctuations in condensed matter materials. To investigate more systems and faster fluctuations by being able to tune the coherence length, we use a zone plate to change the coherence length and beam size but keep most of the intensity. Using the zone plate, experiments were carried out to measure the properties of the focused beam. We applied a formalism to calculate the effect of optics on coherence. We tested our results by doing measurement at Advanced Photon Source. We measured the focal properties of the zone plate, speckle sizes and contrast, obtained by using coherent X-ray diffraction from an disordered Fe3Al crystals. Our theoretical calculations are compared with the experimental results.

Ekokardiografi är en mycket användbar teknik som bland annat kan bedöma vänsterkammarensfunktion hos hjärtat med hjälp av ejektionsfraktion (EF) och global longitudinell strain (GLS). EF är idag den metoden som används mest vid bedömning av vänsterkammarfunktionen och beräknas enligt Simpsons biplanmetod. GLS är en ny metod som mäter myokardiets deformation och har i tidigare studier visat sig vara en känslig metod och kan upptäcka förändringar i myokardiet tidigare än EF. Vid behandling av bröstcancer kan hjärtat påverkas toxiskt och därmed genomgår denna patientgrupp regelbundna kontroller med ekokardiografi.   Syftet med denna studie är att jämföra två ekokardiografiska metoder hos 20 stycken kvinnliga bröstcancerpatienter. Jämförelser har gjorts mellan EF beräknat med Simpsons biplanmetod (EFbi) och GLS samt mellan EFbi och EF beräknat från GLS (EFGLS). Detta är en kvantitativ retrospektiv studie där data insamlats mellan oktober-december 2014 på avdelningen klinisk fysiologi vid Länssjukhuset Ryhov i Jönköping. Den analysmetod som använts är McNemar´s test samt kappavärde. Resultatet av studien visar att EFbi och GLS gav en dålig överenstämmelse mellan metoderna och en rimlig överenstämmelse sågs mellan EFbi och EFGLS. Slutsatsen har dragits utifrån kappavärdet. / Echocardiography is a useful technique which can value the function of the left chamber of the heart by using ejection fraction (EF) and global longitudinal strain (GLS). Today EF is the most common method in assessments of the left chamber function and is calculated by Simpson´s biplanemethod. GLS is a new method that measures the myocardial deformation. It has been proved to be a sensitive method and can detect changes in the myocardium earlier than EF.   The purpose of this study is to compare two echocardiographic methods among 20 female breast cancer patients. Comparisons have been made between EF calculated with Simpson´s biplanemethod (EFbi) and GLS, and between EFbi and EF calculated by GLS (EFGLS). This is a quantitative retrospective study. The data used in this study was collected between October – December 2014 at the Department of Clinical Physiology at the Hospital Ryhov in Jönköping. The method used to analyse the results was McNemar´s test and Kappa value. The results of the study showed that EFbi and GLS gave a modest correspondence between the methods. A reasonable correspondence were observed between EFbi and EFGLS. The conclusion has been drawn from the kappa value.

The objective of this study is to apply digital image processing (DIP) techniques to optical coherence tomography (OCT) images and develop computer-based non-subjective quantitative analysis, which can be used as diagnostic aids in early detection of dental caries. This study first compares speckle reduction effects on raw OCT image data by implementing spatial-domain and transform-domain speckle filtering. Then region-based contour search and global thresholding techniques examine digital OCT images with possible lesions to identify and highlight the presence of features indicating early stage dental caries. The outputs of these processes, which explore the combination of image restoration and segmentation, can be used to distinguish lesion from normal tissue and determine the characteristics prior to, during, and following treatments. The combination of image processing and analysis techniques in this thesis shows potential of detecting early stage caries lesion successfully.

Novel approaches to the determination of material properties and damage parameters of fibre-matrix composites using inverse analysis are presented. In inverse analysis system identification techniques are used to update some form of mathematical model (normally a FE model) using data from an over-determined number of tests. Initially, pultruded GFRP box-section beams are subjected to a quasi-static impact or bending crush. The results of the impact tests are presented to corroborate those in the literature that have been obtained using simpler geometries such as flat plates. In the first form of inverse analysis, a model-updating approach is applied to progressive tearing damage in pultruded composite box-section beams. The difference between empirical data (from a programme of three-point bend tests) and a FE model is minimised by a genetic algorithm to produce an optimal solution. The solution is in the form of a FE model that can be subsequently analysed to determine the structural integrity of the damaged specimen. Secondly, a unidirectional composite disc from the same GFRP pultruded section is analysed in diametral compression to both verify and improve the validity of the diametral compression test in determining the material properties. Coupons are cut from damaged specimens and test results are presented. The strain distribution within the disc is compared to known laminate theory in order to process data obtained by speckle-shearing interferometry. Finally, speckle-shearing interferometry is used to characterise the response of the pultruded box-section exhibiting progressive tearing damage. Out-of-plane displacement-gradient data is used to determine and characterise damaged regions or flaws. The differences between the need to perform it programme of unequivocal static tests and the collection of full-field optical data are highlighted. It is shown that the shearing interferometry approach is the superior method.

Zugl.: München, Techn. Univ., Diss., 2009

Universiẗat, Diss., 1998--Konstanz.

The primary objective of this research is to conduct further evaluation of ultrasonic digital image correlation (UT-DIC) on strain map analysis and defect detection of adhesive joints with embedded speckle pattern. UT-DIC is a non-destructive evaluation method that utilized ultrasonic C-scan images for whole field strain and displacement analysis. Acrylic glass, epoxy resin system and metal shavings with high acoustic impedance of a specific weight were used to create the samples which were loaded under tension. Defects with varying shapes and sizes were implemented by surface preparation to understand the limits of this approach. UT-DIC and optical DIC strain map results were compared, and it was found that each approach detected certain shapes of defect better than the other.