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1
Verviers, Claire Juliette. "The Influence Of Sound Properties On The Semantic Associations Of Product Sounds." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612412/index.pdf.
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To be able to design product sounds that elicit a predetermined expression a study was
performed to find how sound properties influence the experience of their expression. Two
explorative studies using figurative against abstract visual stimuli were performed to
create insight in how people experience sounds and to create a list of usable semantic
associations. This list was ordered in 25 expression categories each under one descriptive
semantic association. A third study using mind mapping was conducted to examine what
sound properties were considered as influences on a few of these categories and to
optimize the categorization. The sound properties that were considered as most influential
were sharpness and noisiness. The final descriptive semantic associations were placed
on a scale with the axes unpleasant-pleasant and calm-active. From these the following
were considered to be most usable: activated, angry, boring, calm, chaotic, cheerful, eerie,
energetic, pleasant, relaxed, trustworthy and unpleasant. In a fourth study the sounds of
six domestic appliances were chosen and adjusted for sharpness, noisiness and their
combination. They were evaluated for their valued expression on the 12 semantic
associations by 30 participants. The results showed that increased sharpness elicited a
more unpleasant and activated expression and decreased sharpness elicited a more
pleasant and calm expression. This indicates that a general influence of sound properties
can be established to design sounds for expression.
2
Fouda, Sherif. "Absorption properties of green sound barriers." Thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239039.
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This thesis was conducted on behalf of Butong AB, who wanted to test and develop an environmental friendly, so called green sound barrier, which combines both art and science.Different configurations of the product were proposed by the company with various filling materials, as it was predicted that the filling materials would be the main sound absorbent among all parts of the structure.The thesis work started by selecting the best of the proposed fillings which could be of interest - that is those which were expected to have high sound absorption coefficients. The selection process was based on experience, reading and advice. The main idea behind the selection process was saving cost for the company as well as effort.Impedance tube method was used for performing the measurements on samples of the green sound barriers, in order to calculate the acoustical properties of each material and every construction, as it was considerably reliable, cheap and fast to use.The measurements were done according to a combination between standards described in ISO 10534-2:1998 and ASTM E2611-09, for performing test measurements using the impedance tube.This master thesis gives an explanation of the predicted absorption characteristics of the green sound barriers including the usage of different fillings, as well as the advantages and disadvantages of using it in real life applications.
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Kari, Leif. "Structure-borne sound properties of vibration isolators /." Stockholm, 1998. http://www.lib.kth.se/abs98/kari0312.pdf.
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Goodwin, Anthony Robert Holmes. "Thermophysical properties from the speed of sound." Thesis, University College London (University of London), 1988. http://discovery.ucl.ac.uk/1317959/.
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The speed of sound in various gases between 250 and 350 K has been obtained from measurements of the frequencies of the radial modes of spherical acoustic resonators; two resonators were used and both apparatus are described. The radius of each resonator was obtained from the speed of sound in argon. Measurements with the 60 mm radius resonator were made below 115 kPa on the six substances: n-butane; methyipropane; n-pentane; methylbutane; dimethylpropane; and, methanol. Perfect gas heat capacities and second and third acoustic virial coefficients for these substances have been calculated from the results, and estimates are given for the second and third (p,Vm,T) virial coefficients. A sealed resonator of radius 40 mm was used to obtain acoustic results below 7 MPa on argon and the industrially important gases methane, a natural gas, and air. Measurements with argon provided an opportunity to study the model used to account for acoustic energy losses in the resonator. The speed of sound, for the industrially important gases, was compared with estimates obtained from several equations of state.
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Overath, T. "Representation of statistical sound properties in human auditory cortex." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/16135/.
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The work carried out in this doctoral thesis investigated the representation of statistical sound properties in human auditory cortex. It addressed four key aspects in auditory neuroscience: the representation of different analysis time windows in auditory cortex; mechanisms for the analysis and segregation of auditory objects; information-theoretic constraints on pitch sequence processing; and the analysis of local and global pitch patterns. The majority of the studies employed a parametric design in which the statistical properties of a single acoustic parameter were altered along a continuum, while keeping other sound properties fixed. The thesis is divided into four parts. Part I (Chapter 1) examines principles of anatomical and functional organisation that constrain the problems addressed. Part II (Chapter 2) introduces approaches to digital stimulus design, principles of functional magnetic resonance imaging (fMRI), and the analysis of fMRI data. Part III (Chapters 3-6) reports five experimental studies. Study 1 controlled the spectrotemporal correlation in complex acoustic spectra and showed that activity in auditory association cortex increases as a function of spectrotemporal correlation. Study 2 demonstrated a functional hierarchy of the representation of auditory object boundaries and object salience. Studies 3 and 4 investigated cortical mechanisms for encoding entropy in pitch sequences and showed that the planum temporale acts as a computational hub, requiring more computational resources for sequences with high entropy than for those with high redundancy. Study 5 provided evidence for a hierarchical organisation of local and global pitch pattern processing in neurologically normal participants. Finally, Part IV (Chapter 7) concludes with a general discussion of the results and future perspectives.
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Ramanathan, Sathish Kumar. "Sound transmission properties of honeycomb panels and double-walled structures." Doctoral thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96538.
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Sandwich panels with aluminium face sheets and honeycomb core material have certain advantages over panels made of wood. Some of the advantages of these constructions are low weight, good moisture properties, fire resistance and high stiffness to-weight ratio etc. As product development is carried out in a fast pace today, there is a strong need for validated prediction tools to assist during early design stages. In this thesis, tools are developed for predicting the sound transmission through honeycomb panels, typical for inner floors in trains and later through double-walled structures typical for rail-vehicles, aircrafts and ships. The sandwich theory for wave propagation and standard orthotropic plate theory is used to predict the sound transmission loss of honeycomb panels. Honeycomb is an anisotropic material which when used as a core in a sandwich panel, results in a panel with anisotropic properties. In this thesis, honeycomb panels are treated as being orthotropic and the wavenumbers are calculated for the two principal directions. The wavenumbers are then used to calculate the sound transmission using standard orthotropic theory. These predictions are validated with results from sound transmission measurements. The influence of constrained layer damping treatments on the sound transmission loss of these panels is investigated. Results show that, after the damping treatment, the sound transmission loss of an acoustically bad panel and a normal pane lare very similar. Further, sound transmission through a double-leaf partition based on a honeycomb panel with periodic stiffeners is investigated. The structural response of the periodic structure due to a harmonic excitation is expressed in terms of a series of space harmonics and virtual work theory is applied to calculate the sound transmission. The original model is refined to include sound absorption in the cavity and to account for the orthotropic property of the honeycomb panels. Since the solution of the space harmonic analysis is obtained in a series form, a sufficient number of terms has to be included in the calculation to ensure small errors. Computational accuracy needs to be balanced with computational cost as calculation times increases with the number of terms. A new criterion is introduced which reduces the computational time by up to a factor ten for the panels studied. For all the double-leaf systems analysed, the sound transmission loss predictions from the periodic model with the space harmonic expansion method are shown to compare well with laboratory measurements.QC 20120607
7
Perron, Robert A. "Measurement of bubble properties using a multi-frequency sound field." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26057.
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Wertel, Scotty John. "Experimental analysis of noise reduction properties of sound absorbing foam." Online version, 2001. http://www.uwstout.edu/lib/thesis/2001/2001wertels.pdf.
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Santos, Sharon Marie. "Tactile and Visual Sound: A Music Cooperative for the Adams Morgan Community." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/36480.
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McNett, Gabriel Dion. "Noise and signal transmission properties as agents of selection in the vibrational communication environment." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4677.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 25, 2008) Vita. Includes bibliographical references.
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Estrada-Alexanders, Andres Francisco. "Thermodynamic properties of gases from measurements of the speed of sound." Thesis, Imperial College London, 1996. http://hdl.handle.net/10044/1/8048.
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Hedfors, Per. "Site soundscapes : landscape architecture in the light of sound /." Uppsala : Dept. of Landscape Planning Ultuna, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a407.pdf.
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Puentes, Heras M. "The use of SAW methods in probing near-surface elastic properties." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299101.
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Van, Veen Tobias C. "Reconstruction & rhythm science : networks and properties of remix culture." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=83153.
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The following thesis explores the conditions of possibility for remix culture through the work of Paul D. Miller, a.k.a. Dj Spooky that Subliminal Kid. Beginning with the impact and vertigo of Dj Spooky's language and practice, it explores the reciprocal relation of media to language in the construction of the proper (property) and the author (authority). The context of Dj Spooky as a conceptual artist and the material of his book, Rhythm Science , provides the setting and scenario for extended readings of the paradoxes and cultural effects of remix culture, including the relation of writing to djing, practices of incorporative media, tactics of digital email, combat over copyright, and the sampling of the archive. The formalization of these effects is outlined by writing in-between the theories of Gilles Deleuze and Jacques Derrida. This formalization signals the advent of the network over the territory, the form over the content, the formal over the expressive (while nonetheless recognising the distinction, persistence and difference of these terms). It argues that remix culture regenerates and redefines the parameters of the author and the proper through technological and political forces that nonetheless retain their structures of power. The conduit and context of this formal, paradoxical transformation are the cultural forces of global and digital networks, which is here defined as the "oceanic network."
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Lin, Chih-wei. "Thermophysical properties of industrial fluids at high pressures from sound speed and density measurements." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/23788.
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The objective of this project was to provide reliable thermophysical property data, mainly density and sound speed, for industrial and academic use. This thesis investigates in detail the speed of sound and density of several industrial fluids at pressure up to 400 MPa and temperature from 248 K to 473 K. The experimental technique used was based on an ultrasonic cell implementing a double-path pulse-echo method with an ultrasound transducer placed between two unequally-spaced reflectors. The cell was calibrated in water at T = 298.15 K and p = 1 MPa against the speed of sound given by the 1995 equation-of-state formulation of the International Association for the Properties of Water and Steam (IAPWS-95) which, for that state point, has an uncertainty of ± 0.005 %. In this thesis, the ultrasonic cell was validated by water measurement over a wide range of temperature and pressure and was shown to have an uncertainty of ± 0.03 %. The uncertainty of the sound speed measurement for other fluids in general is less than 0.1 %. In addition, a densimeter was also used. The measured sound speed and density combined with the heat capacity can be used to develop advanced analytical equations of state and derive all of the thermodynamic properties for key mixtures by numerical-integration algorithms. All the thermophysical properties measured in this thesis were correlated into equations as a function of temperature and pressure. The correlated parameters were calculated by regression analysis in Microsoft Excel. The regression function is used to minimize the sum of squares of error of all the data which needs to be fitted into an equation. In our regression analysis from Excel, the objective was to fit the data to within the target uncertainty using the number of parameters required. Several working fluids were studied: pure water, hexafluoropropene (HFP), trifluoro-3-(trifluoromethyl)oxirane (common name hexafluoropropylene oxide, HFPO), carbon dioxide, and carbon dioxide + propane mixtures. The results extend our understanding of the thermophysical properties of these key industrial fluids and may lead to the development of improved thermodynamic models for application in air conditioning, refrigeration system and carbon capture and storage applications.
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Wu, Ruimeng. "UTILIZATION OF EMPIRICAL MODELS TO DETERMINE THE BULK PROPERTIES OF COMPRESSED SOUND ABSORPTIVE MATERIALS." UKnowledge, 2017. https://uknowledge.uky.edu/me_etds/106.
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Empirical models based on flow resistivity are commonly used to determine the bulk properties of porous sound absorbing materials. The bulk properties include the complex wavenumber and complex characteristic impedance which can be used directly in simulation models. Moreover, the bulk properties can also be utilized to determine the normal incidence sound absorption and specific acoustic impedance for sound absorbing materials of any thickness and for design of layered materials. The sound absorption coefficient of sound absorbing materials is measured in an impedance tube using wave decomposition and the measured data is used to determine the flow resistivity of the materials by least squares curve fitting to empirical equations. Results for several commonly used foams and fibers are tabulated to form a rudimentary materials database. The same approach is then used to determine the flow resistivity of compressed sound absorbing materials. The flow resistivities of the compressed materials are determined as a function of the compression ratio. Results are then used in conjunction with transfer matrix theory to predict the sound absorptive performance of layered compressed absorbers with good agreement to measurement.
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Kumar, Gaurav. "Structual-acoustic properties of automotive panels with shell elements." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/13950.
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The automotive industry has witnessed a trend in the recent years of reducing the bulk weight of the vehicle in order to achieve improved ride dynamics and economical fuel consumption. Unfortunately, reducing the bulk weight often compromises the noise, vibra- tion, and harshness (NVH) characteristics of the vehicle. In general, the automotive body panels are made out of thin sheet metals (steel and aluminium) that have a very low bend- ing stiffness. Hence, it becomes important to find countermeasures that will increase the structural stiffness of these thin body panels without affecting their bulk weight. One such countermeasure is to introduce the geometrical indentations on various body panels. The geometrical indentation explained in this thesis is in the shape of elliptical dome, which supports the increase of the structural stiffness whilst keeping the bulk weight constant. The primary reason to choose elliptical domes as the applied geometrical indentation is due to a significant amount of interest shown by Jaguar Land Rover. Moreover, the elliptical domes, because of the nature of its design, can cover a larger surface area with minimal depth, thereby, eliminating the possibility of sharp and pointy indentations. This thesis presents a comprehensive study of the structural-acoustic behaviour of the automotive-type panels with dome-shaped indentations. The ultimate aim of this research is to establish a set of design guidelines in order to produce automotive-type panels with optimised dome-shaped indentations. In order to do so, a new design optimisation strategy is proposed that results in the optimal placement of the required dome-shaped indenta- tions. The optimisation problem addressed in this thesis is unlike a general mathematical problem, and requires specific methodologies for its solution. Therefore, the use of genetic algorithm is observed as the most suitable method in order to tackle this type of design optimisation problem. During the development of the optimisation procedure, the preliminary results show a consistency in the design patterns. This led to the motivation to investigate a few intuitively designed panels, which are inspired by the initial, trial, optimisation results. Therefore, four intuitively designed panels are investigated for their structural-acoustic characteristics. The study of the intuitively designed panels provided essential physical insight into the design optimisation problem, which ultimately defined the guidelines in order to develop the proposed optimisation procedure. This type of optimisation procedure is completely new in the domain of structural-acoustic optimisation. The efficiency of the underlying work lies in the separate investigation of both the structural and the acoustic properties of the panels with various dome-shaped indentations, and then utilising the insights gained in order to develop a specific optimisation algorithm to stream-line the dome-shaped panel design procedure.
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Hart, Heledd. "Characterisation of responses of human auditory cortex to basic sound properties, as measured using fMRI." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272359.
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Atkins, Gordon J. "Identified, sound-sensitive interneurons in the cricket : response properties, morphology, and relationships between structure and function." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72091.
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The responses and morphology of nine sound-sensitive interneurons are described in the cricket Teleogryllus oceanicus. Each of the neurons receives direction-specific input in the prothoracic ganglion, and each projects at least one interganglionic axon. Five of the neurons respond best to high frequencies ($>$10 kHz); four are most sensitive to low frequencies (3-10 kHz). Responsiveness to model calling songs was examined in addition to testing sensitivity to wind and light. Anatomical observations reveal that seven of the neurons receive auditory input via polysynaptic pathways, and that at least five of the neurons have morphology consistent with them providing input to mesothoracic motor neurons which are involved in behavioral responses to sound. Correlations between structure, topographic organization, and spectral sensitivity were found. The structure of one previously identified, auditory neuron was examined and found to change during late post-embryonic life. This represents a novel developmental pattern.
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Stevenson, Samuel D. F. "Experimental investigations of lip motion in brass instrument playing." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4349.
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The precise nature of the motion of the lips of the musician is critically important to the sound of the brass wind instrument. The player must match the oscillation of the lips to the acoustical properties of the instrument and it can take many years of practice to master the techniques involved. Visualisation techniques for capturing the motion of the lips during performance are described and the behaviour of the lips quantitatively analysed using digital image analysis. The concept of an artificial mouth for the sounding of brass wind instruments is discussed and the motion of the artificial lips is compared to that of human musicians. When a brass instrument is played loudly the energy of the higher harmonics increases, creating a distinctive ‘brassy’ timbre. It has been suggested that saturation or constraint of the lips of the musician during extremely loud playing is responsible for this change in sound. Measurements of the motion of the lips of a number of different musicians on different instruments suggest that the lips are not significantly constrained at any playing dynamic, and that it is the phenomena of nonlinear propagation and shockwave generation that is responsible for the increase in energy of the higher harmonics. It is widely accepted that the starting transient of a musical instrument is of great importance to both listener and musician. Previous studies of brass instruments have focused on the steady-state behaviour of the lip-instrument interaction. Measurements of the motion of the lips have been synchronised with the pressure in the mouthpiece of the instrument and the sound radiated from the bell in order to investigate the transient behaviour of the system during both the starting transient and slurs between notes. Thiswork has been extended to include measurements of the pressure in the mouth of the player during the starting transient, and this information used to recreate realistic transients using an artificial mouth. The transient behaviour of the system is clearly affected by the time delay between the start of the note and the acoustical feedback from the instrument beginning. The information obtained can be used to aid in the creation of accurate computational and physical models of brass wind instruments.
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Foa, Clare. "The sound of positive emotion: The vocal acoustic properties involved in the expression and perception of interest." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96978.
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Emotion plays an important role in psychotherapy. In order to understand more about the interaction between emotional functioning and the psychotherapeutic process, research into the moment to moment fluctuations of emotional experience is essential. However, subjective measurement of the momentary changes of emotion has proved problematic. The current body of work seeks to address this measurement challenge by examining the vocal acoustic properties of participants' speech within therapeutic style interviews, specifically, the momentary fluctuations of the emotion of interest. A second study examines the vocal cues that trainee therapists use in deciphering participants' emotional processing. Results revealed that the vocal parameters of fundamental frequency, volume intensity, volume variance and speech rate changed with participants' self-rated emotional intensity to indicate unique vocal profiles at different levels of participants' interest. The vocal parameters of volume and frequency variance were the vocal cues trainee therapists relied on in decoding the emotional quality of participants' speech.This work seeks to inform future research in the development of ecologically valid instruments with which to assess in-session emotion and offers contributions to the fields of emotion and psychotherapy process research, as well as to the field of psychotherapy training models.L'émotion joue un rôle important dans la psychothérapie. Afin de mieux comprendre l'interaction entre le fonctionnement affectif et le processus psychothérapeutique, la recherche sur les fluctuations momentanées de l'expérience émotionnelle est essentielle. Cependant, la mesure subjective de l'évolution de l'émotion momentanée s'est révélée problématique. La présente étude vise à relever ce défi de mesure en examinant les propriétés vocales acoustiques de la parole des participants dans les interviews de style thérapeutique, en particulier les fluctuations momentanées de l'émotion d'intérêt. Une deuxième étude examine les signes vocaux utilisés par les thérapeutes stagiaires pour déchiffrer les processus émotionnels des participants. Les résultats ont révélé que les paramètres vocaux de fréquence fondamentale, d'intensité du volume, de variation du volume et de débit de la parole ont changé avec l'auto-évaluation de l'intensité émotionnelle des participants pour indiquer des profils vocaux uniques à différents niveaux de l'intérêt des participants. Les paramètres vocaux de volume et de variation du fréquence ont servi d'indices vocaux aux thérapeutes pour décoder la qualité émotionnelle de la parole des participants.Ce travail vise à informer les recherches futures dans l'élaboration d'instruments valides sur le plan écologique, permettant d'évaluer l'émotion dans la session thérapeutique. Il contribue au domaine de la recherche sur les processus thérapeutiques ainsi qu'aux modèles de formation en psychothérapie.
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Meng, Han. "Acoustic properties of novel multifunctional sandwich structures and porous absorbing materials." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC008/document.
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La mise en oeuvre de matériaux acoustiques est une méthode efficace et très utilisée pour réduire le bruit le long de sa propagation. Les propriétés acoustiques de nouvelles structures sandwich multifonctionnelles et de matériaux absorbants poreux sont étudiées dans la thèse. Les principales contributions de la thèse sont les suivantes: Les panneaux sandwich ont généralement d'excellentes propriétés mécaniques et un bon indice de perte en transmission sonore (STL), mais aucune capacité d'absorption acoustique. De nouvelles structures sandwich multifonctionnelles sont développées en intégrant des microperforations et des matériaux absorbants poreux aux panneaux sandwich ondulés et en nid d’abeilles conventionnels, structurellement efficaces pour obtenir de bons STL et de bonnes absorptions en basses fréquences. Le coefficient d'absorption acoustique (SAC) et la perte en transmission (STL) des panneaux sandwich ondulés sont évalués numériquement et expérimentalement en basse fréquence pour différentes configurations de perforations. Les modèles éléments finis (EF) sont construits en tenant compte des interactions vibro-acoustiques sur les structures et des dissipations d'énergie, visqueuse et thermique, à l'intérieur des perforations. La validité des calculs FE est vérifiée par des mesures expérimentales avec les échantillons testés obtenus par fabrication additive. Par rapport aux panneaux sandwich ondulés classiques sans perforation, les panneaux sandwich perforés (PCSPs) avec des perforations dans leur plaque avant présentent non seulement un SAC plus élevé aux basses fréquences, mais aussi un meilleur STL, qui en est la conséquence directe. L'élargissement des courbes des indices d’absorption et de transmission doit être attribué à la résonance acoustique induite par les micro-perforations. Il est également constaté que les PCSPs avec des perforations dans les plaques avant et les parois internes onduleés ont les fréquences de résonance les plus basses de tous les PCSPs. En outre, les performances acoustiques des panneaux sandwich en nid d'abeilles avec une plaque avant microperforée sont également examinées. Un modèle analytique est présenté avec l'hypothèse que les déplacements des deux plaques sont identiques aux fréquences inférieures à la fréquence de résonance des plaques. Le modèle analytique est ensuite validé par des modèles d'éléments finis et des résultats expérimentaux existants. Contrairement aux panneaux sandwich en nid d'abeilles classiques qui sont de piètres absorbeurs de bruit, les sandwichs en nid d'abeilles perforés (PHSPs) conduisent à un SAC élevé aux basses fréquences, ce qui entraîne en conséquence un incrément dans le STL basse fréquence. Les influences de la configuration du noyau sont étudiées en comparant les PHSPs avec différentes configurations de noyaux en nids d'abeilles. […]Implementation of acoustic materials is an effective and popular noise reduction method during propagation. Acoustic properties of novel multifunctional sandwich structures and porous absorbing materials are studied in the dissertation. The main contributions of the dissertation are given as, Sandwich panels generally have excellent mechanical properties and good sound transmission loss (STL), but no sound absorption ability. Novel multifunctional sandwich structures are developed by integrating micro perforations and porous absorbing materials to the conventional structurally-efficient corrugated and honeycomb sandwich panels to achieve good SAC and STL at low frequencies. Low frequency sound absorption and sound transmission loss (STL) of corrugated sandwich panels with different perforation configurations are evaluated both numerically and experimentally. Finite element (FE) models are constructed with considerations of acousticstructure interactions and viscous and thermal energy dissipations inside the perforations. The validity of FE calculations is checked against experimental measurements with the tested samples provided by additive manufacturing. Compared with the classical corrugated sandwich panels without perforation, the perforated corrugated sandwich panels (PCSPs) with perforations in its face plate not only exhibits a higher SAC at low frequencies but also a better STL as a consequence of the enlarged SAC. The enlargement of SAC and STL should be attributed to the acoustical resonance induced by the micro perforations. It is also found that the PCSPs with perforations in both the face plates and corrugated cores have the lowest resonance frequencies of all the PCSPs. Besides, the acoustic properties of honeycomb sandwich panels with microperforated faceplate are also explored. An analytical model is presented with the assumption that displacements of the two faceplates are identical at frequencies below the faceplate resonance frequency. The analytical model is subsequently verified by finite element models and existing experimental results. Unlike classical honeycomb sandwich panels which are poor sound absorbers, perforated honeycomb sandwiches (PHSPs) lead to high SAC at low frequencies, which in turn brings about increment in the low frequency STL. Influences of core configuration are investigated by comparing PHSPs with different honeycomb core configurations. In order to enlarge the SAC bandwidth of perforated sandwich panels, porous absorbing materials are added to the cores of novel perforated sandwich panels. FE models are set up to estimate the SAC and STL of perforated sandwich panels with porous materials. Results show that perforated sandwich panels with porous material can provide SAC with broader bandwidth and lower resonance frequency than that without porous materials. Whereas the peak values in the SAC and STL curves are reduced due to the weakened acoustical resonance by the porous materials. […]
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Wiryana, Surya. "Physical properties of aqueous solutions under high pressures and temperatures /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8691.
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Mahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
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This thesis is concerned with developing porous materials from tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy exchanges. The materials developed are also able to insulate against heat by suppressing the convection of heat and reduced conductivity of the fluid locked in the large proportion of close-cell pores. The acoustic absorption performance of a porous media is controlled by the number of open cells and pore size distribution. Therefore, this work also investigates the use of catalysts and surfactants to modify the pore structure and studies the influence of the various components in the chemical formulations used to produce these porous materials. An optimum type and amounts of catalyst are selected to obtain a high chemical conversion and a short expanding time for the bubble growth phase. The surfactant is used to reduce the surface tension and achieve a homogenous mixing between the solid particulates tyre shred residue, the water, the catalyst and the binder. It is found that all of the components significantly affect the resultant materials structure and its morphology. The results show that the catalyst has a particularly strong effect on the pore structure and the ensuing thermal and acoustical properties. In this research, the properties of the porous materials developed are characterized using standard experimental techniques and the acoustic and thermal insulation performance underpinned using theoretical models. The important observation from this research is that a new class of recycled materials with pore stratification has been developed. It is shown that the pore stratification can have a positive effect on the acoustic absorption in a broadband frequency range. The control of reaction time in the foaming process is a key function that leads to a gradual change in the pore size distribution, porosity, flow resistivity and tortuosity which vary as a function of sample depth. It is shown that the Pade approximation is a suitable model to study the acoustic behaviour of these materials. A good agreement between the measured data and the model was attained.
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Foulkes, Philip James. "A grid based approach for the control and recall of the properties of IEEE 1394 audio devices." Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1004836.
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The control of modern audio studios is complex. Audio mixing desks have grown to the point where they contain thousands of parameters. The control surfaces of these devices do not reflect the routing and signal processing capabilities that the devices are capable of. Software audio mixing desk editors have been developed that allow for the remote control of these devices, but their graphical user interfaces retain the complexities of the audio mixing desk that they represent. In this thesis, we propose a grid approach to audio mixing. The developed grid audio mixing desk editor represents an audio mixing desk as a series of graphical routing matrices. These routing matrices expose the various signal processing points and signal flows that exist within an audio mixing desk. The routing matrices allow for audio signals to be routed within the device, and allow for the device’s parameters to be adjusted by selecting the appropriate signal processing points. With the use of the programming interfaces that are defined as part of the Studio Connections – Total Recall SDK, the audio mixing desk editor was integrated with compatible DAW applications to provide persistence of audio mixing desk parameter states. Many audio studios currently use digital networks to connect audio devices together. Audio and control signals are patched between devices through the use of software patchbays that run on computers. We propose a double grid-based FireWire patchbay aimed to simplify the patching of signals between audio devices on a FireWire network. The FireWire patchbay was implemented in such a way such that it can host software device editors that are Studio Connections compatible. This has allowed software device editors to be associated with the devices that are represented on the FireWire patchbay, thus allowing for studio wide control from a single application. The double grid-based patchbay was implemented such that it can be hosted by compatible DAW applications. Through this, the double grid-based patchbay application is able to provide the DAW application with the state of the parameters of the devices in a studio, as well as the connections between them. The DAW application may save this state data to its native song files. This state data may be passed back to the double grid-based patchbay when the song file is reloaded at a later stage. This state data may then be used by the patchbay to restore the parameters of the patchbay and its device editors to a previous state. This restored state may then be transferred to the hardware devices being represented by the patchbay.
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Dubberke, Frithjof H. [Verfasser]. "Thermophysical properties from experimental speed of sound measurements for working fluids in organic Rankine cycles / Frithjof H. Dubberke." Paderborn : Universitätsbibliothek, 2017. http://d-nb.info/1166751856/34.
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Holland, Keith Robert. "A study of the physical properties of mid-range loudspeaker horns and their relationship to perceived sound quality." Thesis, University of Southampton, 1992. https://eprints.soton.ac.uk/64783/.
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Tai, Chih-Che, and Laura Robertson. "Hands-on Activities in Properties of Matter and Sound and Wave Movement: A Learning Progression Approach in K-8." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/777.
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Peyvandi, A. "A study of the causes of variation of the sound insulation properties of party floors in newly converted dwellings." Thesis, London South Bank University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618630.
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Huang, Weichun. "Acoustic properties of natural materials." Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1031/document.
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Dans cette thèse, nous étudions un métamatériau inspiré de la paille de blé pour l'absorption parfaite du son. Une botte de paille estidéalisée comme un milieu poreux anisotrope, composé d’un arrangement périodique très concentré de tubes creux cylindriques. L’approche théorique de ce métamatériau repose sur l'homogénéisation asymptotique à deux échelles d'un réseau perméable de résonateursparfaitement rigides dont la physique est enrichi par des résonances internes. Les principales caractéristiques de ce milieu poreux sont lacompressibilité effective négative autour de la résonance du tube et la réduction drastique de la vitesse de propagation du son (slowsound) à très basse fréquence. Une configuration optimale est conçue, basée sur la condition de couplage critique, pour laquelle la fuited’énergie du système résonnant ouvert est parfaitement compensée par les pertes intrinsèques induites par les pertes viscothermiques.Des mesures en tube à impédance sont effectuées sur des échantillons fabriqués par impression additive pour valider les résultatsthéoriques. Nous montrons que ce métamatériau est un absorbeur sub-longueur d'onde capable d’une absorption parfaite à très bassefréquence et d'introduire une quasi-bande interdite autour de la résonance du tube. De plus, la nature anisotrope de ce matériau conduit àune absorption globalement élevée à basse fréquence et ce pour toutes les incidences. Cette étude offre la possibilité de concevoir unabsorbeur acoustique sélectif en angle et en fréquence. Pour conclure, les résultats de cette thèse montrent que la paille est un boncandidat pour une absorption acoustique parfaiteStraw-inspired metamaterials for sound absorption are investigated in this Thesis. A straw stack is idealized as a highly concentratedresonant anisotropic porous medium constituted of a periodic arrangement of densely packed cylindrical hollow tubes. The approach tothis metamaterial relies on the two-scale asymptotic homogenization of a permeable array of perfectly rigid resonators, where the physicsis further enriched by tailoring inner resonances. The main features of such sound absorbing medium are the possibility for the effectivecompressibility to become negative around the tube resonance and the drastic reduction of the effective sound speed (slow sound) at verylow frequency in the system. Moreover, an optimal configuration for sound absorption is designed, based on the critical couplingcondition, in which the energy leakage out of the open resonant system is perfectly compensated by the intrinsic losses induced by thevisco-thermal losses both in the anisotropic matrix and in the resonators. Impedance tube measurements are performed on 3-D printedsamples with controlled parameters to validate the theoretical results. This metamaterial is a sub-wavelength absorber that can achievetotal absorption at a very low frequency and possesses a quasi-band-gap around the tube resonance. Furthermore, the anisotropic nature ofthe configuration gives rise to high absorption at low-frequency range for all incidences and diffuse field excitation. It paves the way tothe design of angular and frequency selective sound absorber. To conclude, the results of this Thesis show that straw is a good candidatefor perfect sound absorption
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Li, Wanlu. "EXPERIMENTAL STUDIES ON THE DETERMINATION OF ACOUSTIC BULK MATERIAL PROPERTIES AND TRANSFER IMPEDANCE." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/48.
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Soft trim absorbing parts (i.e., headliners, backwalls, side panels, etc.) are normally comprised of different layers including films, adhesives, foams and fibers. Several approaches to determine the complex wavenumber and characteristic impedance for porous sound absorbing materials are surveyed and the advantages and disadvantages of each approach are discussed. It is concluded that the recently documented three-point method produces the smoothest results. It is also shown that measurement of the flow resistance and the use of empirical equations is sufficient for many common materials. Following this, the transfer impedance of covers, adhesives, and densified layers are measured using an impedance difference approach. The transfer matrix method was then used to predict the sound absorption of a multi-layered materal which included a perforated cover, fiber layers, and an adhesive. The predicted results agree well with measurement.
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Ambróz, Richard. "Analysis of Powertrain Acoustic Properties." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-234137.
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Dizertačná práca rieši problematiku analýzy akustických vlastností pohonných jednotiek. V úvodnej časti je teoretický rozbor fyzikálnych princípov vibrácií a hluku a prehľad súčasného stavu riešenia problematiky v oblasti návrhu pohonných jednotiek. Vlastná časť práce popisuje konštrukčný návrh elektrodynamického budiča vibrácií, návrh hodnotenia výsledkov merania a taktiež spôsob spracovania výsledkov. Akustické vlastnosti sú hodnotené pomocou normálových rýchlostí kmitania povrchu. V závere práce sú prezentované ukážky využitia metódy v praktických príkladoch spojených s návrhom pohonnej jednotky. Celé riešenie predstavuje ucelený spôsob analýzy vhodný pre rýchle hodnotenie vplyvu konštrukčných úprav na akustické vlastnosti.
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NOGUEIRA, GESSE E. C. "Extensao da faixa de velocidades mensuraveis do velocimetro Doppler ultra-sonico pulsatil." reponame:Repositório Institucional do IPEN, 1995. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10431.
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Made available in DSpace on 2014-10-09T12:38:39Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:05:15Z (GMT). No. of bitstreams: 1 06042.pdf: 9369626 bytes, checksum: 37950a2f878d6535f671de4a025da71c (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Al-Ameer, A. S. "Some studies of the properties of high Tc superconductors and their use as bolometers at low temperatures in measurements of the sound velocity in '4He gas." Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232895.
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Dietzen, Gregory C. "Acoustic scattering from sand dollars (Dendraster Excentricus) : modeling as high aspect ratio oblate objects and comparison to experiment." Thesis, Online version of original thesis, 2008. http://hdl.handle.net/1912/2499.
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Oliveira, Fabrício Borges. "O ultra-som terapêutico adicionado à imobilização gessada nas propriedades mecânicas da reparação muscular pós-trauma por mecanismo de impacto." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-29032006-110757/.
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Desenvolvemos um instrumento capaz de provocar uma lesão muscular aguda por mecanismo de impacto, no músculo gastrocnêmio de ratas, através de um trauma direto e não-invasivo. Após a produção da lesão experimental avaliamos os efeitos do ultra-som terapêutico (UST), adicionado ou não à imobilização gessada, como forma de tratamento imediato à lesão muscular pela análise das propriedades mecânicas deste músculo. Foram utilizadas 68 ratas da raça Wistar, sendo divididas em 7 grupos experimentais da seguinte forma: Grupo 1 Controle intacto; Grupo 2 Sem tratamento efetivo, Grupo 3 Imobilização gessada por 24 horas; Grupo 4 Imobilização gessada por 72 horas; Grupo 5 Estimulação com UST sem presença de imobilização; Grupo 6 Imobilização gessada por 24 horas associada à estimulação com UST; Grupo 7 Imobilização gessada por 72 horas associada à estimulação com UST tratadas durante 6 dias consecutivos com UST, durante 5 minutos diários. Avaliamos as propriedades mecânicas obtidas através de ensaios mecânicos de tração longitudinal e os resultados foram analisados estatisticamente. O estudo evidenciou que a propriedade de alongamento no limite de proporcionalidade não foi um bom parâmetro de correlação para avaliar a efetividade dos tratamentos empregados junto ao processo de reparação muscular. A utilização isolada do UST como técnica de tratamento apresentou melhores resultados em relação às propriedades mecânicas de carga no limite de proporcionalidade, rigidez, resiliência, carga e alongamento máximo. No entanto, a utilização da imobilização gessada por 72 horas associada ou não a estimulação ultra-sônica foi capaz de proporcionar melhorias somente em relação ao alongamento máximo. Sugere-se ainda, que a utilização da imobilização gessada por períodos de 24 horas associada ou não ao uso do UST não foi capaz de apresentar resultados benéficos para as propriedades mecânicas avaliadasWe developed an instrument capable to provoke a muscular injury acute for impact mechanism, in the muscle gastrocnemius of female rats, through a direct and non-invasive. After the production of experimental injury we evaluate the effects of the therapeutic ultrasound (UST), added or not to the cast immobilization, as form of immediate treatment to the muscular injury, for the analysis of the mechanical properties of this muscle. Sixty eight female Wistar rats were used and being divided in seven experimental groups: Group 1 Intact Control; Group 2 Without treatment; Group 3 -Immobilization in spica cast for 24 hours; Group 4 - Immobilization in spica cast for 72 hours; Group 5 Stimulation with UST without immobilization presence; Group 6 - Immobilization in spica cast for 24 hours associated to the stimulation with UST and Group 7 - Immobilization in spica cast for 72 hours associated to the stimulation with UST, treated during six consecutive days with UST, for five minutes daily. We evaluted properties we carry through assays of logitudinal traction in the universal machine of assays and the gotten results had been analyzed statical test. The study it evidenced that the property of proportional limit strength in the was not a good parameter of correlation to evaluate the effectiveness of the employed treatments together to the process of muscular repairing. The isolated use of the UST as treatment technique presented better resulted in relation to the mechanical load properties in the proportional limits, stiffness, resilience, load and strength maximum. However, the use of the spica cast for periods of 72 hours associated or not ultrasound stimulation was not capable to only provide improvements in relation to the maximum strength. One still suggests, that the use of the spica cast in the immobilization for 24 hours periods associate or not to the use of the UST was not capable to present resulted beneficial for the evaluated mechanical properties
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Hunt, Stephanie L. "Collagen Crosslinking Reagent Utilized to Modify the Mechanical Properties of the Soft Palate in Equine Snoring and Apnea Applications." UKnowledge, 2015. http://uknowledge.uky.edu/cbme_etds/36.
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Snoring is a sleep disruption that can lead to obstructive sleep apnea (OSA), which interrupts breathing by obstructing the airway. Injecting a protein crosslinker, such as genipin, into the soft palate could decrease the severity of snoring and OSA by stiffening the soft palate. Equine soft palates modeled human palates due to a high incidence of awake snoring and apnea.
The pilot in vivo study treated six horses with two 100 mM injections of the buffered genipin reagent. The efficacy phase horses underwent respiratory audio recordings to document snoring changes using Matlab and ImageJ in the time and frequency domains. Histological analysis was completed on the safety phase palates post treatment.
All horses were successfully treated with the genipin injections. At least one horse showed high frequency amplitude reductions, and all horses had low frequency amplitude reductions, correlating to a reduction in palatal displacement and snoring loudness. One efficacy horse appears to have been completely cured. The histological analysis presented tissue damage, mucosal tissue damage, and mild inflammation due to palate expansion and errant injections.
Different injection volumes and techniques should be investigated next. Applying this treatment to human studies for snoring and OSA applications is the ultimate goal.
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Scholz, Christian Werner [Verfasser], Roland [Gutachter] Span, and Markus [Gutachter] Richter. "Thermodynamic properties of liquids and gas mixtures as contribution to a sustainable energy supply : measurements of density and speed of sound / Christian Werner Scholz ; Gutachter: Roland Span, Markus Richter ; Fakultät für Maschinenbau." Bochum : Ruhr-Universität Bochum, 2021. http://d-nb.info/1239418884/34.
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Bozhko, Andrii. "Physical Boundary as a Source of Anomalies in Transport Processes in Acoustics and Electrodynamics." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404590/.
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Various anomalous effects that emerge when the interfaces between media are involved in sound-matter or light-matter interactions are studied. The three specific systems examined are a fluid channel between elastic metal plates, a linear chain of metallic perforated cylindrical shells in air, and a metal-dielectric slab with the interfaces treated as finite regions of smoothly changing material properties. The scattering of acoustic signals on the first two is predicted to be accompanied by the effects of redirection and splitting of sound. In the third system, which supports the propagation of surface plasmons, it is discovered that the transition region introduces a nonradiative decay mechanism which adds to the plasmon dissipation. The analytical results are supported with numerical simulations. The outlined phenomena provide the ideas and implications for applications involving manipulation of sound or excitation of surface plasmons.
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Doherty, John Houston. "Landmine detection with a standoff acoustic/laser technique." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46058.
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Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2008.Includes bibliographical references (p. 54-56).
Landmines and mine-like traps are effective weapons that are difficult to detect and discriminate from a safe distance. The ability to detect landmines in their host environment at a distance and to discriminate them from other objects would be valuable for countering the landmine threat. This paper explores a standoff acoustic/laser technique to discriminate landmines from other forms of man-made objects (clutter) in an urban environment. A novel approach currently under investigation by MIT Lincoln Labs, University of Mississippi, and other groups employs a non-contact acoustic/laser technique to detect landmines from a safe standoff range. This technique uses a sound source to excite vibrations in targets with an acoustic wave. These vibrations are in turn measured remotely with a Laser Doppler Vibrometer (LDV). In this thesis, the vibration responses of landmine variants are measured, analyzed, and compared to those of common urban objects likely to be found on a landmine field or roadside. The Fourier Transform of the vibration of the target as measured by the LDV is used to generate a target vibration spectrum. Target vibration spectra in response to a sound source were experimentally measured for 59 trials, 28 of which were of simulated landmine variants and the remaining trials were of urban clutter objects. Using an algorithm adapted from a methodology for mass spectral analysis, parameters of the target signatures are estimated; then individual target signatures are classified using a Support Vector Machine (SVM) with a training set composed of parameters from the remaining members of the total population. The best results obtained from this methodology had a 71% probability of detection and a 3% false alarm rate corresponding to 20 of 28 of the simulated landmine variants correctly identified and a single clutter object misidentified as a landmine variant.
by John Houston Doherty.
S.M.
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Almansour, Amjad Saleh Ali. "USE OF SINGLE TOW CERAMIC MATRIX MINICOMPOSITES TO DETERMINE FUNDAMENTAL ROOM AND ELEVATED TEMPERATURE PROPERTIES." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron148640184494135.
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Randolph, Mark Anthony. "Syllable-based constraints on properties of English sounds." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14213.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.Includes bibliographical references (leaves 169-174).
by Mark Anthony Randolph.
Ph.D.
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Täschner, Dirk. "Untersuchungen der akustischen Wirkung von Tragrollen zur zielgerichteten Lärmminderung an Gurtförderanlagen." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2017. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-220185.
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Gurtförderanlagen werden im Bergbau und anderen Industriezweigen zum Transport von Schüttgütern eingesetzt. Der Anlagenbetrieb ist mit Geräuschemissionen verbunden. Dies kann bei Kontrolle und Wartung eine erhöhte Lärmbelastung für betroffene Mitarbeiter hervorrufen. Im Umfeld von Wohnbebauungen oder schutzbedürftigen Objekten kann die Überschreitung von Immissionsrichtwerten zu einer zeitlichen Betriebseinschränkung der hocheffizienten Anlagen führen. Zur Lärmminderung an der Quelle oder deren Nähe erfordert dies technische Schallschutzmaßnahmen. Die Tragrollen im Obertrum der Gurtförderanlagen sind bei der akustischen Wirkung von entscheidender Bedeutung. Mit einem Prüfstand für Tragrollen ist deren Schallleistung bei unterschiedlichen Geschwindigkeiten bestimmbar. Die Ergebnisse lassen Rückschlüsse auf die mechanische Belastung und die Schallemission beim Betrieb in einer Förderanlage zu. Die Arbeit benennt die Ursachen der Geräuschemissionen beim Ablauf der Rollen und stellt diese in Verbindung mit den Eigenschaften der Oberfläche und der Außermittigkeit der Drehachse dar. Die Prüfung beider Parameter basiert auf einer Rundlaufmessung. Die gewonnenen winkelabhängigen Daten erlauben eine Berechnung der Exzentrizität der Drehachse und des Verlaufs der Kreisformabweichung auf dem Rollenmantel. Daraus abgeleitete Kennwerte dienen als Vorgaben zur Anpassung und Entwicklung von Herstellungsverfahren sowie zur gezielten Auswahl geräuscharmer Tragrollen für GurtförderanlagenBelt conveyor systems are used in mining operations and other industry sectors to transport bulk material. The plant operation is being linked to noise emissions. During inspections and maintenance this can cause an increased noise exposure for affected employees. In the environment of residential buildings or areas in need of protection the exceedance of immission guideline values can lead to a temporary operational limitation of these highly efficient plants. Noise abatement measures primarily at the source or in the vicinity are required to reduce noise immission. The idlers on the carrying belt side of the belt conveyor systems are of crucial importance to the acoustical properties. Their sound power level is determinable at different belt speeds with a test stand for idlers. The results allow conclusions about the mechanical stress and sound emissions during operation in a belt conveyor system. The thesis identifies the sources of noise during the roll process and places them in conjunction with the properties of the surface and the centre offset of the axis. The examination of these two parameters is based on a total indicator reading (TIR) measurement. The angle-dependent data obtained allow a calculation of the eccentricity of the axis and the curve of the circular deviation of the roller tubes. Therefrom derived characteristic values serve as specifications for the adaptation and development of manufacturing processes as well as for a careful selection of low noise idlers for belt conveyors
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Rusina, Michal. "Stanovení vlastností ultrazvukových sond." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221368.
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This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.
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Azarbarzin, Ali. "Snoring sounds analysis: automatic detection, higher order statistics, and its application for sleep apnea diagnosis." IEEE, 2011. http://hdl.handle.net/1993/9593.
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Snoring is a highly prevalent disorder affecting 20-40% of adult population. Snoring
is also a major indicative of obstructive sleep apnea (OSA). Despite the magnitude of effort, the acoustical properties of snoring in relation to physiological states are not yet known.
This thesis explores statistical properties of snoring sounds and their association with OSA. First, an unsupervised technique was developed to automatically extract the snoring sound segments from the lengthy recordings of respiratory sounds.
This technique was tested over 5665 snoring sound segments of 30 participants and the detection accuracy of 98.6% was obtained. Second, the relationship between anthropometric parameters of snorers with different degrees of obstruction and their snoring sounds’ statistical characteristics
was investigated. Snoring sounds are non-Gaussian in nature; thus second order statistical methods such as power spectral analysis would be inadequate to extract information from snoring sounds. Therefore, higher order statistical features, in addition to the second order ones, were extracted. Third, the variability of snoring sound segments within and between 57 snorers with and without OSA was investigated. It was found that the sound characteristics
of non-apneic (when there is no apneic event), hypopneic (when there is hypopnea), and post-apneic (after apnea) snoring events were significantly different.
Then, this variability of snoring sounds was used as a signature to discriminate the non-OSA snorers from OSA snorers. The accuracy was found to be 96.4%.
Finally, it was observed that some snorers formed distinct clusters of snoring sounds in a multidimensional feature space. Hence, using Polysomnography (PSG) information, the dependency of snoring sounds on body position, sleep stage, and blood oxygen level was investigated. It was found that all the three variables affected snoring sounds. However, body position was found to have the highest effect on the characteristics of snoring sounds.
In conclusion, snoring sounds analysis offers valuable information on the upper airway physiological state and pathology. Thus, snoring sound analysis may further
find its use in determining the exact state and location of obstruction.
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Selhorst, Rosalie. "Trädens inre och yttre ljud - med olika mätmetoder." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-93665.
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Syftet med denna studie var att beskriva mätmetoder, som mäter träets egenskaper med hjälp av vågrörelser respektive mätmetoder som mäter träds egna vågrörelser. Vidare att undersöka hur människor uppfattar musik från trädens egna ljud (vågrörelser). Resultaten visar att det finns flera olika mätmetoder som främst mäter kvalité i träd och virke. Ytterligare två mätmetoder finns och de tar hjälp av sensorer, synthesizers och en örontrumpet, och mäter främst elektriska impulser, ljud och ljudvågor. Resultaten visar även att människor är positivt inställda till musik som kommer från träden. Slutsatsen som kan dras från detta arbete är att det finns många olika sätt att mäta och lyssna på träden på.The purpose of this study was to describe measurement methods, which measure the properties of the wood using wave movements and measurement methods that measure the tree's own wave movements. Further to investigate how people perceive music from the trees' own sounds (wave movements). The results show that there are several different measuring methods that primarily measure quality in trees and wood. Two other measuring methods are available, and they use sensors, synthesizers and an ear trumpet, and mainly measure electrical impulses, sounds and sound waves. The results also show that people are positively attuned to music that come from trees. The conclusion that can be drawn from this work is that there are many different ways to measure and listen to the trees.
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Castelli, Eric. "Caractérisation acoustique des voyelles nasales du français : mesures, modélisation et simulation temporelle." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0055.
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Hansson, Tomas. "When the Siren Sounds : In Search of Acoustic Properties that make an Alarm Signal Effective at Capturing Attention." Thesis, Högskolan i Gävle, Miljöpsykologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-26905.
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A functional and effective alarm signal is a critical component of alarm systems designed to alert workers of impending danger. In a previous study (Hansson, 2017) background alarm sirens composed of changing-state sounds with an embedded temporal deviant, produced greater disruption of serial short-term memory than a signal without a deviant. However, to give rise to disruption the siren needed to change from fast to slow, since a change from slow to fast was impotent in its effect on task performance. In the current study, whether acoustic change was a necessary prerequisite for obtaining the fast-to-slow deviant effect was explored. Thus, repeated tones—steady-state sequences—presented at slow or fast rates were used with or without a temporal deviant (change from slow-to-fast vs. change from fast-to-slow). In the context of the steady-state sequences, both slow-to-fast and fast-to-slow temporal deviants produced disruption relative to the fast and slow control sequences. This suggests that a changing-state sequence is required for the fast-to-slow temporal deviant effect to arise. However, an alternative explanation based upon inter-stimulus intervals is also entertained. Understanding the acoustic parameters of sound is necessary to develop alarms sirens that are better at capturing attention. The current study suggests that embedding temporal deviants within sirens can promote greater attentional capture, but that this may depend on the nature of the alarm signal (whether it is changing vs. steady-state) and the direction of the change of speed (slow-to-fast vs. fast-to-slow).
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Siemes, Kerstin. "Establishing a sea bottom model by applying a multi-sensor acoustic remote sensing approach." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209381.
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Detailed information about the oceanic environment is essential for many applications in the field of marine geology, marine biology, coastal engineering, and marine operations. Especially, knowledge of the properties of the sediment body is often required. Acoustic remote sensing techniques have become highly attractive for classifying the sea bottom and for mapping the sediment properties, due to their high coverage capabilities and low costs compared to common sampling methods. In the last decades, a number of different acoustic devices and related techniques for analyzing their signals have evolved. Each sensor has its specific application due to limitations in the frequency range and resolution. In practice, often a single acoustic tool is chosen based on the current application, supported by other non-acoustic data where required. However, different acoustic remote sensing techniques can supplement each other, as shown in this thesis. Even more, a combination of complementary approaches can contribute to the proper understanding of sound propagation, which is essential when using sound for environmental classification purposes. This includes the knowledge of the relation between acoustics and sediment properties, the focus of this thesis. Providing a detailed three dimensional picture of the sea bottom sediments that allows for gaining maximum insight into this relation is aimed at.Chapters 4 and 5 are adapted from published work, with permission:
DOI:10.1121/1.3569718 (link: http://asadl.org/jasa/resource/1/jasman/v129/i5/p2878_s1) and
DOI:10.1109/JOE.2010.2066711 (link: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5618582&queryText%3Dsiemes)
In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of the Université libre de Bruxelles' products or services.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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da, Cunha Daise Nunes Queiroz. "Properties of Flow Through the Ascending Aorta in Boxer Dogs with Mild Aortic Stenosis: Momentum, Energy, Reynolds Number, Womersley’s, Unsteadiness Parameter, Vortex Shedding, and Transfer Function of Oscillations from Aorta to Thoracic Wall." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243910694.
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