In this report we investigate whether an embedded system can be used to determine materials quality by analysing the acoustic resonance frequencies. Through experiments the necessary specifications are established and suitable circuits constructed. Signal analysis is performed by a FFT-based algorithm. We have verified that the system is succesful in detecting the five strongest resonance frequencies and list these in order of amplitude. By using embedded devices, it's possible to lower the cost of purchase as well as power consumption dramatically compared to alternative solutions. / I denna rapport undersöker vi hurvida ett inbyggt system kan användas för att bestämma materialkvalité genom analys av akustiska resonansfrekvenser. Genom experiment fastställs de specifikationer systemet måste ha, varefter lämpliga kretsar konstrueras. Med hjälp av en FFT-baserad algoritm utförs viss signalanalys. Vi har verifierat att systemet framgångsrikt kan detektera de fem starkaste resonansfrekvenserna och lista dessa efter amplitud. Genom användandet av inbyggda system kan energiförbrukningen och inköpskostnaden bli mycket lägre än alternativa lösningar.

A general three-dimensional hydroelasticity theory for the evaluation of responses has been adapted to formulate hydrodynamic coefficients for submerged shell-type structures. The derivation of the theory has been presented and is placed in context with other methods of analysis. The ability of this form of analysis to offer an insight into the physical behaviour of practical systems is demonstrated. The influence of external boundaries and fluid viscosity was considered separately using a flexible cylinder as the model. When the surrounding fluid is water, viscosity was assessed to be significant for slender structural members and flexible pipes and in situations where the clearance to an outer casing was slight. To validate the three-dimensional hydroelasticity theory, predictions of resonance frequencies and mode shapes were compared, with measured data from trials undertaken in enclosed tanks. These data exhibited differences due to the position of the test structures in relation to free and fixed boundaries. The rationale of the testing programme and practical considerations of instrumentation, capture and storage of data are described in detail. At first sight a relatively unsophisticated analytical method appeared to offer better correlation with the measured data than the hydroelastic solution. This impression was mistaken, the agreement was merely fortuitous as only the hydroelastic approach is capable of reproducing-the trends recorded in the experiments. The significance of an accurate dynamic analysis using finite elements and the influence of physical factors such as buoyancy on the predicted results are also examined.

This thesis present novel non-destructive laboratory test methods to characterize asphalt concrete. The testing is based on frequency response measurements of specimens where resonance frequencies play a key role to derive material properties such as the complex modulus and complex Poisson’s ratio. These material properties are directly related to pavement quality and used in thickness design of pavements. Since conventional cyclic loading is expensive, time consuming and complicated to perform, there has been a growing interest to apply resonance and ultrasonic testing to estimate the material properties of asphalt concrete. Most of these applications have been based on analytical approximations which are limited to characterizing the complex modulus at one frequency per temperature. This is a significant limitation due to the strong frequency dependency of asphalt concrete. In this thesis, numerical methods are applied to develop a methodology based on modal testing of laboratory samples to characterize material properties over a wide frequency and temperature range (i.e. a master curve). The resonance frequency measurements are performed by exciting the specimens using an impact hammer and through a non-contact approach using a speaker. An accelerometer is used to measure the resulting vibration of the specimen. The material properties can be derived from these measurements since resonance frequencies of a solid are a function of the stiffness, mass, dimensions and boundary conditions. The methodology based on modal testing to characterize the material properties has been developed through the work presented in paper I and II, compared to conventional cyclic loading in paper III and IV and used to observe deviations from isotropic linear viscoelastic behavior in paper V. In paper VI, detailed measurements of resonance frequencies have been performed to study the possibility to detect damage and potential healing of asphalt concrete.  The resonance testing are performed at low strain levels (~10^-7) which gives a direct link to surface wave testing of pavements in the field. This enables non-destructive quality control of pavements, since the field measurements are performed at approximately the same frequency range and strain level. / <p>QC 20141117</p>

Ce travail de thèse interroge le lien qui existe entre voix et genre. Le triple dispositif analytique sociophonétique, consistant à articuler données phonétiques, expérimentales et ethnographiques, a permis d’étudier comment une voix est perçue comme genrée et comment des locutrices/eurs utilisent des pratiques vocales pour indexer des identités de genre. Deux expériences dans lesquelles étaient utilisés comme stimuli des voix de synthèse et des voix resynthétisées ont permis d’observer que la fréquence fondamentale et les fréquences de résonance jouent des rôles différents dans la perception du genre. Une troisième expérience avec des voix de locutrices/eurs trans (transgenres, transsexuel-le-s) a permis de reproduire les résultats des deux expériences précédentes : en deçà d’un certain seuil de fréquence fondamentale, les voix tendent à être perçues comme « voix d’hommes » ; la perception genrée de voix produites avec des fréquences fondamentales supérieures à ce seuil est cependant largement déterminée par les fréquences de résonance.L’étude de pratiques vocales utilisées par des locutrices/eurs trans a soulevé un ensemble de questions sur le passing de genre et sur la co-indexation d’identités et de postures par la voix. Elle a aussi soulevé la question de la légitimité de chercheurs identifiés comme hommes cisgenres à réaliser ce type d’étude. Une démarche ethnographique a pu apporter des éléments de réponse à ces différentes questions. Une analyse de la littérature phonétique a finalement permis de montrer que celle-ci, à travers ses questions et hypothèses de recherche, ses axiomes, ses analyses et interprétations des données, peut véhiculer une idéologie de genre binaire et sexiste. / The aim of this dissertation is to investigate the relationship between voice and gender. Phonetic, experimental and ethnographic data have been used to study how the voice is perceived as gendered and how speakers use vocal practices to index gender identities. Two experiments with synthetized and resynthesized voices have shown that fundamental frequency and resonance frequencies play different roles in the perception of gender. The results of these experiments could be reproduced in a third experiment with voices of transgender speakers: under a certain fundamental frequency threshold, voices tend to be perceived as “male voices”; but above this threshold, resonance frequencies define if the voice is perceived as “female voice” or “male voice”. The study of the vocal practices of transgender speakers raised questions about gender passing, and about the indexical link between identities, stances and voice. It also raised the question of the legitimacy of researchers that are identified as cisgender males to do research on trans speaker voices. These different questions could be addressed through ethnographic data. Finally, an analysis of the phonetic literature showed that the research questions and hypotheses, the axioms, the analyses and interpretations of data one can find in phonetic studies can be a vehicle for a sexist and binary gender ideology.