Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 45 for “"Vibrometry"”.
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Contactless material sensing with wireless mmwave vibrometry
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01
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Three-dimensional velocity extraction using laser Doppler vibrometry
In the analysis of plates and beams, in-plane velocities have been assumed to be small and negligible. This was nearly an unavoidable assumption due to the fact that the in-plane velocity was near impossible to determine accurately with conventional techniques. This assumption needs to be checked …
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Vehicle Engine Classification Using of Laser Vibrometry Feature Extraction
<p>Used as a non-invasive and remote sensor, the laser Doppler vibrometer (LDV) has been used in many different applications, such as inspection of aircrafts, bridge and structure and remote voice acquisition. However, using LDV as a vehicle surveillance device has not been feasible due to the lack …
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Laser Doppler Vibrometry Based Remote Sensing for Active Noise Control
… of many ANC applications. Laser Doppler vibrometry, which works on the principle of optical interferometry, has been widely used in to measure vibrations in many vibro-acoustic applications. Yet, the developed instrument, laser Doppler vibrometer (LDV), has little been studied in the …
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Information Processing for Biological Signals: Application to Laser Doppler Vibrometry
Signals associated with biological activity in the human body can be of great value in clinical and security applications. Since direct measurements of critical biological activity are often difficult to acquire noninvasively, many biological signals are measured from the surface of the skin. This …
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Vibrations of high-speed dental handpieces measured using laser vibrometry
Objective: To measure in vitro vibration displacement amplitudes of high-speed dental handpieces under unloaded and loaded conditions using a non-contact Scanning Laser Vibrometer (SLV). Methods: Five turbines (two KaVo, three W&H) and two speed-increasing handpieces (one KaVo and one W&H) were …
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Hydrogel Design Optimization for Measuring Ultrasound Using Laser Doppler Vibrometry
… acoustic wave generation, laser doppler vibrometry (LDV), and LabView integration. High speed data acquisition (DAQ) through a dedicated Pico Technology setup streams digitized data directly to the host PC. LDV measurements highlighted the crucial role of bead concentration within …
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Remote nondestructive evaluation of composite-steel interface by acoustic laser vibrometry
… of nondestructive testing (NDT). Acoustic laser vibrometry is a relatively new method of NDT that shows a lot of promise in analysis of this interface. In this approach, an airborne acoustic wave is utilized to excite the location of the damage underneath the FRP sheets/plates and the target …
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Detection of defects in FRP-reinforced concrete with the acoustic-laser vibrometry method
… A novel approach called the acoustic-laser vibrometry method which is capable of remote assessment of damage in FRP-reinforced concrete, is investigated in this thesis. It exploits the fact that areas where the FRP has debonded from concrete will vibrate excessively compared to intact …
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Three-dimensional vibrometry via three positions of a one-dimensional laser doppler velocimeter
A technique to determine the three-dimensional velocity of a point on a vibrating structure is developed. This technique uses a reference-beam type laser-doppler velocimeter in three independent positions to determine the target velocity in a non orthogonal coordinate system. The transformation …
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Static Misalignment Effects is a Self-Tracking Laser Vibrometry System for Rotating Bladed Disks
The application of laser Doppler vibrometry to high speed rotating structures has been hampered by technical limitations. Whereas full-field three-dimensional velocity measurements can be made on stationary structures, the capability on rotating structures is limited to low speed, one-dimensional, …
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The assessment of ultrasonic instruments in dentistry
… have previously been difficult to analyse. Laser vibrometry is a non-invasive technique for measuring the vibration characteristics of oscillating objects. Aim: The aim of this research thesis was to utilise scanning laser vibrometry to assess a range of dental ultrasonic systems under various …
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Material, acoustic, and mechanical properties of mosquito and midge antennae
… Finite Element Modelling (FEM) and Laser Doppler Vibrometry (LDV) were employed. The combination of the first two allows, in absence of prior knowledge of the material properties of mosquito or midge antennae, to assess the material structure and to gauge which impact this distribution can have on …
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Development of a Novel Thermal Shock test for isostatically Pressed Carbon-Bonded Refractories
… image correlation (DIC) and laser Doppler vibrometry (LDV), were employed. Because of the novelty of Laser Doppler Vibrometry for refractories damage assessment, the outputs of this method were validated against acoustic-emission signals recorded during stress-strain cycles in separate …
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Biomechanical and neurophysiological investigation of insect tympanal organs
… species and orders of insect using laser Doppler vibrometry. The results were then compared between species, including the different structures and also the membrane mechanics. This chapter results highlights the different structures and also the range of frequencies that each species is tuned to. …
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Do Butterflies Use "Hearing Aids"?Investigating the Structure and Function of Inflated Wing Veins in Nymphalidae
… and evolution of these inflated veins. A laser vibrometry study showed that ears in the common wood nymph, Cercyonis pegala, are tuned to sounds between 1-5 kHz and the inflated subcostal vein enhances sensitivity to these sounds. A comparative study showed that all species with inflated veins …
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Physics and Algorithms in Time of Flight Based Computational Imaging
… resolution by using ideas from optics, laser vibrometry, and signal processing.
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Misalignment Effects of the Self-Tracking Laser Doppler Vibrometer
… describes aspects of a self-tracking laser vibrometry system that can be used to measure the vibrations of rotating structures. This method, if setup correctly, has the capability to overcome many of the limitations listed above. A study of all misalignment effects is presented in this …
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