Дисертації з теми "Bee sounds"
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Bricout, Augustin. "Instrumentation embarquée avec correction déterministe et exploitation par IA de capteurs électroniques : application à la surveillance de ruches." Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEI019.
Повний текст джерелаThe objective of this thesis is to develop low-cost smart sensing solutions, enhancing inexpensive sensors through software-based corrections. Rather than designing high-performance but expensive sensors, this approach aims to create low-cost sensors that are then corrected and optimized via embedded algorithms. Recent electronic architectures now offer sufficient computational power to perform these corrections directly at the measurement source, known as edge computing, while maintaining extremely low energy consumption, making battery-powered systems viable.Two software correction approaches are explored: a method based on a deterministic algorithm, and a second method relying on artificial intelligence. After designing a data collection architecture suited for beehives, both approaches are implemented. The first, deterministic approach is used to correct data from strain gauges in the context of a hive scale. The second method is applied to MEMS audio sensors, to extract bee colony health metrics using machine learning techniques
Trevathan, Jeremy. "Sound transmission through walls: A coupled BEM/FEM approach." Thesis, University of Canterbury. Mechanical Engineering, 2005. http://hdl.handle.net/10092/5922.
Повний текст джерелаGEORGE, JOHN K. "ANALYTICAL, NUMERICAL AND EXPERIMENTAL CALCULATION OF SOUND TRANSMISSION LOSS CHARACTERISTICS OF SINGLE WALLED MUFFLER SHELLS." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1181226367.
Повний текст джерелаLyvers, Christina M. "EVALUATION OF HANDLING EQUIPMENT SOUND PRESSURE LEVELS AS STRESSORS IN BEEF CATTLE." UKnowledge, 2013. http://uknowledge.uky.edu/bae_etds/13.
Повний текст джерелаWilsdorf, Michael, Gabi Fischer, and Astrid Ziemann. "Einfluss der vertikalen Auflösung der Eingangsprofile bei einem Schallstrahlenmodell." Universität Leipzig, 2009. https://ul.qucosa.de/id/qucosa%3A16343.
Повний текст джерелаIn the following article, effects of the vertical resolution of input data on numerical sound attenuation simulations are investigated. The reason for this lies in the occurrence of a „layer problem“ during work with such a model. That means, even larger the vertical resolution of the input profiles is, so much more the calculated answer deviates from the analytic. Therefore, different vertical resolutions are examined. The analyzed results show that a higher resolution can solve this problem. Calculations are carried out using the sound ray model SMART which considers the dependency of sound ray propagation on stratified atmosphere. As a basis for calculating the sound ray paths interpolated and climatologically classified profiles of temperature and wind obtained from radiosonde data are utilized. These investigations provide a basis for the analysis and interpretation of attenuation calculations derived from a sound ray model.
Root, Pierce Denise Lyn. "Applying the Study of Bel Canto Vocal Technique to Artistic Horn Playing: Perfect Legato, Beautiful Sound, Agility, and Musical Expression." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/272836.
Повний текст джерелаStruhařová, Michaela. "Zvuková postprodukce v oblasti reklamy a filmu, případová studie firmy Studio Beep s.r.o." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-199246.
Повний текст джерелаvon, Malmborg Solvej, and Tony Martinsson. "Whee da-dum bee-dum : Melodisk kontur hos ljudlogotyper och dess påverkan på varumärkesuppfattning." Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-18605.
Повний текст джерелаAn audio logo, also called sonic logo or sound logo, is a sound composition utilized to differentiate a brand. A sonic logo is part of a brand’s strategy to create an image in the awareness of consumers. This image is called brand perception. The objective of this study was to expand general knowledge about music’s applicability for communicative purposes and moreover to specifically look at how melody affects brand perception. A web survey was conducted to investigate if different types of melodic contour in an audio logo can have different effects on the perception of brand identity for a fictional brand. Participants were recruited using social media. Eight videos consisting of an audio logo and a graphic logo were designed. The videos were identical apart from their melodic contours. Participants rated the degree to which they perceived five different personality traits for the audio logo they heard. The results were analyzed statistically. Through the survey, no support was generated for an impact from the type of melodic contour on the perception of the five personality traits. Appropriate methods for investigating audio logos and brand perception are discussed. For future research within the field qualitative design is suggested, as well asinvestigations into other musical parameters. Furthermore, additional research into melodic contour is proposed.
Schlittmeier, Sabine. "Arbeitsgedächtnis und Hintergrundschall : gibt es einen "irrelevant sound effect" bei auditiv präsentierten Items? /." Berlin : Logos-Verl, 2005. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013201496&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Повний текст джерелаDefine, Lynn Dorsey. "Popular Culture, Thomas Beer, and the Making of "The Sound and the Fury"." W&M ScholarWorks, 1994. https://scholarworks.wm.edu/etd/1539625894.
Повний текст джерелаTrbovich, Victoria R. "The Effects of Sous Vide Cooking on Tenderness and Protein Concentration in Young Fed Beef and Cow Semitendinosus Muscles." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511910815944282.
Повний текст джерелаWielgus, Alison Lynn. "You had to have been there : experimental film and video, sound, and liveness in the New York underground." Diss., University of Iowa, 2014. https://ir.uiowa.edu/etd/4794.
Повний текст джерелаMoura, Giselle Borges de. "Vocalização de suínos em grupo sob diferentes condições térmicas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11131/tde-26042013-094034/.
Повний текст джерелаTo quantify and to qualify animal well-being in livestock farms is still a challenge. To assess animal well-being, it must be analyzed, mainly, the absence of strong negative feelings, like pain, and the presence of positive feelings, like pleasure. The main objective was to quantify vocalization in a group of pigs under different thermal conditions. The specific objectives were to assess the existence of vocal pattern of communication between housing groups of pigs, and get the acoustic characteristics of the sound spectrum from the vocalizations related to the different microclimate conditions. The trial was carried out in a controlled environment experimental unit for pigs, at the University of Illinois (USA). Four groups of six pigs were used in the data collection. Dataloggers were installed to record environmental variables (T, °C and RH, %). These environmental variable were used to calculate two thermal comfort index: Enthalpy and THI. Cardioid microphones were installed to record continuous vocalizations in the geometric center of each pen where the pigs were housing. Microphones were connected to an amplifier, and this was connected to a dvr card installed in a computer to record audio and video information. For doing the sound edition in a pig vocalization database, the Goldwave® software was used to separate, and filter the files excluding background noise. In the sequence, the sounds were analyzed using the software Sounds Analysis Pro 2011, and the acoustic characteristics were extracted. Amplitude (dB), pitch (Hz), mean frequency (Hz), peak frequency (Hz) and entropy were used to characterize the sound spectrum of vocalizations of the groups of piglets in the different thermal conditions. A randomized block design was used, composed by two treatments and three repetitions in a week and executed in two weeks. Data were sampled to analyze the behavior of the databank of vocalization as a relation to the applied treatments. Data were submitted to an analysis of variance using the proc GLM of SAS. Among the studied acoustic parameters, the amplitude (dB), pitch and entropy. The treatments (comfort and heat stress conditions) presented significative differences, through Tukey\'s test (p<0,05). The analysis of variance showed differences to the wave format to each thermal condition in the different periods of the day. The quantification of vocalization of swine in groups under different thermal conditions is possible, using the extraction of acoustic characteristics from the sound samples. The sound spectrum was extracted, which indicated possible alterations in the piglets behavior in the different thermal conditions during the periods of the day. However, the stage of pattern\'s recognition still needs a larger and more consistent database to the recognition of the spectrum in each thermal condition, through image analysis or by the extraction of the acoustic characteristics. Among he analyzed acoustic characteristics, the amplitude (dB), pitch (Hz) and entropy of the vocalizations of groups of swine were significative to express the condition of the animals in different thermal conditions.
Bacchi, Vito. "Etude expérimentale de la dynamique sédimentaire d'un système à forte pente soumis à des conditions hydrauliques faibles." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00625381.
Повний текст джерелаMažuolis, Jurgis. "Vėjo jėgainių keliamo triukšmo bei apsaugos priemonių tyrimas ir vertinimas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140211_122038-13515.
Повний текст джерелаThe dissertation examines the issue of noise emission from the wind farms. The objects of investigation are wind farm noise and environmentally friendly low-frequency noise-deadening materials with cylindrical structure. The paper addresses a number of key objectives: to determine and assess low frequency noise and infrasound emission and dispersion both inside and outside the industrial wind farms, as well as to establish effective measures for protection of settlements against low-frequency noise generated by wind turbines. The dissertation consists of an introduction, three chapters, conclusions, recommendations, list of references and the author's publications on the topics. The introductory chapter discusses the research problem, the relevance of the investigation, describes the object of the research, states the aims and objectives, presents the research methodology, scientific novelty, practical significance of the results, and the statements for defending. It also highlights practical significance of the dissertation presents the author's publications and presentations at conferences, and explains the structure of the thesis. The first chapter is devoted to literature review. It provides an overview of general problems related to wind and noise produced by wind turbines, an overview of the outlook on wind energy in Lithuania, and a discussion of wind turbine constructions. The chapter presents the analysis of aerodynamic noise emitted by means of low-frequency noise... [to full text]
Hofmann, Frank. "Untersuchungen zur Verbesserung der Resultatqualität bei Suchverfahren über Web-Archive." Thesis, Universitätsbibliothek Chemnitz, 2003. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200300132.
Повний текст джерелаPrölß, Andrea [Verfasser], Thomas [Akademischer Betreuer] Lachmann, and Maria [Akademischer Betreuer] Klatte. "Wirkungen akustischer Umweltbedingungen auf Arbeitsgedächtnisleistungen bei Kindern und Erwachsenen: Experimentelle Untersuchungen zum "Irrelevant Sound Effect" / Andrea Prölß. Betreuer: Thomas Lachmann ; Maria Klatte." Kaiserslautern : Technische Universität Kaiserslautern, 2014. http://d-nb.info/1053653492/34.
Повний текст джерелаAlarid, Renee Aurelia. "Propolis: Immersive Environment." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/102378.
Повний текст джерелаMaster of Fine Arts
"Honey bees have been on the decline. As of 2016, eight species of bees made it on the United States (U.S.) endangered species list. It reported that the decline of pollinators is due to industrial agriculture, parasites, pathogens, and climate change" (Contributors 2020). The loss of habitat and lack of nectar is due to monocultures and bee-killing pesticides. These are significant threats to honey bees and wild pollinators. There is a need for good, clean food providing for a healthy existence for the honey bee. When bees have proper nutrients, the result is a healthy hive that gives mature bees a better chance to fight off diseases. To showcase the life of a honey bee, this researcher created an immersive environment that simulates a hive structure. The structure, along with the motion graphics and critical takeaway printed pieces, is to help children between the ages of 3-10 understand the importance of honey bees. By comparing healthy and unhealthy bees in their natural habitat in an illustration format, the children could empathize with the honey bees. Hopefully, they will one day change the fate of these amazing creatures. The immersive environment will emulate a spatial audio, 2D character illustration, and animation projected onto a honeycomb structure. Custom seed packets and a brochure will accompany the immersive environment to allow the children to plant a bee-friendly garden and to learn more about the honey bees. This capstone project will showcase the researcher's skills in graphic design, spatial sound, architecture, exhibition design, and character illustration. This structure will allow individuals to observe, determine, and make comparisons between a healthy colony and one that is fragile and dying.
Borges, Giselle. "Utilização da pressão sonora (ruído) como indicativo de bem-estar animal na produção industrial de suínos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11131/tde-10022009-103022/.
Повний текст джерелаThe objective of this research was to insert in the market of intensive swine production, a non invasive method to quantify animal welfare, through sound pressure levels (noises) emitted by swine in pre-nursering and nursering phases. Were realized three experiments to study the appliance of sound pressure (noise) emitted by a group of swine as an answer to the environment conditions that they were submitted in a controlled and in a intensive production environment, and to establish the bands of sound pressure according to the bands of temperature and humidity to comfort and stress. In experiment I, the objective was to study the influence of the distribution of the decibelimeters on the automatic capturing of sound pressure levels in a intensive production environment. It was conducted in a commercial swine farm, where a sheds room was used, which was divided in ten identical quadrants and the decibelimeters installed in the geometric centre of each quadrant. Environments sound pressure levels were registered in all equipments, at the same time, and through geostatistical analysis, it was possible to verify that the decibelimeters did not show spatial dependence amongst, and this affirmation could be confirmed by correlation analysis between each decibelimeter tested to each of the evaluated layouts. In experiment II the influence of environment variables on sound pressure levels emitted by piglets in a controlled environment was evaluated. Piglets were confined in a climatic chamber and submitted to a variation of environments temperature and relative humidity. Behaviour was evaluated through piglets activity level using image analysis. Sound pressure levels emitted by piglets were registered by decibelimeters, and backgrounds noise extraction was possible after the removing of piglets of the chamber. It was possible to conclude that sound pressure levels emitted by piglets in a climatic chamber showed a negative correlation with temperature variable and with the enthalpy comfort index. It was possible to predict sound pressure levels bands emitted by piglets, related to comfort and stress bands existents to temperature and enthalpy comfort index to the conditions of the present experiment. Experiment III was conducted in a farm of swines commercial production, and the objective was to evaluate the influence of environment variables on sound pressure levels emitted by piglets in a intensive confinement. Decibelimeters were installed to the automatic capture of sound pressure levels and loggers to collect temperature and air humidity data in a room of swines shed. To the capturing of backgrounds sound pressure level, were installed decibelimeters in the external área to nurserings room to a posterior subtraction. Data were submitted to correlation and regression analysis among the studied variables. It was verified that sound pressure levels emitted by piglets showed a raise tendency when in thermal discomfort, and it was possible to predict bands of sound pressure emitted by piglets in relation to environmental conditions.
Ye, Jiahao. "Etude anatomique de l'amygdale étendue centrale chez la souris : connectivité générale et circuits cellule-spécifiques ; implications fonctionnelles dans la douleur." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ006/document.
Повний текст джерелаCentral extended amygdala (EAc) is a forebrain macrosystem that plays important roles in fear, anxiety and pain. The two key components, the lateral bed nucleus of stria terminalis (STL) and central nucleus of amygdala (CeA), are highly similar in their neurochemical, connectional, and functional features. Despite this simplified view of STL and CeA, much remains elusive of the mesoscopic inputs and outputs of EAc subdivisions in mouse model. Also, it is not known whether the connectional similarities are also shared at cellular level. Here, we addressed these question in comparative ways in mice. We found rich preferential inputs and outputs to different subdivisions of EAc, as well as convergent and divergent inputs. We also found two non-overlapping cell groups expressing either protein kinase C delta (PKCδ) or somatostatin (SOM) organize the parallel cell-type specific neuronal circuits in STL and CeA. Finally, preliminary data suggest that PKCδ in STL and CeA might be implicated in tonic pain. These parallel but also differential structural organizations of neuronal circuits in EAc might underlie similar and dissociable functional aspects of anxiety, fear and pain
Unrath, Jens. "Analyse und Bewertung von Parametern der Produktionsumwelt bei der Milchgewinnung mit automatischen Melksystemen (AMS)." Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2005. http://dx.doi.org/10.18452/15182.
Повний текст джерелаAutomatic milking systems (AMS) are considered as the most recent innovation in the area of milking technology. In comparison with conventional milking parlour they show a set of specific characteristics. Optimal microclimatic conditions in the milking box are necessary to motivate the cows to visit the milking system voluntarily and regularly. The analysis of the microclimatic conditions in AMS took place on a farm with two AMS working parallel and 110 lactating cows. The parameters examined were: the air quality in the milking box and in the barn, the noise load within the milking box during milking as well as the degree of pollution and the germ load at relevant points of the AMS. To mark the seasonal influences on the climate within the barn, the investigations took place in March 2002, June 2002 as well as January 2003. A special microclimatic situation in the milking box was noticed in the analyses for the barn air parameters carbon dioxide and methane. Whenever a cow was in the milking box, increased concentrations were observed. The construction method of the AMS in the head area of the milking box was determined as main reason for the high concentrations of gases, since this impedes the interchange of air with the environment. The sound load for the cows within the milking box was particularly heavy during the preparation of the udder. The sound level was highest during the cleaning of the udder and the frequencies shifted into the higher range. The description of the hygienic conditions in an AMS was first approached by means of digital pictures, which were made at the interfaces between animal, final product and technology. The visually perceptible degree of pollution could be set in relation to Dab RPR, which were taken at the same time like the digital pictures, and isolated germs therein. An improvement and/or an adjustment of the microclimatic situation within AMS appears necessary in order to achieve a sufficient motivation of the cows to go into the milking box.
Leonhardt, Marion. "Conséquences neuroendocriennes et métaboliques d'une sous-nutrition maternelle périnatale chez le rat." Lille 1, 2003. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/21b2f981-03b3-4580-bee6-9c6342089656.
Повний текст джерелаLisse, Albert. "Handlungsspielräume deutscher Verwaltungsstellen bei den Konfiskationen in der SBZ 1945-1949 : zum Verhältnis zwischen deutschen Verwaltungsstellen und der Sowjetischen Militäradministration in Deutschland (SMAD) /." Stuttgart : F. Steiner, 2003. http://catalogue.bnf.fr/ark:/12148/cb39985957g.
Повний текст джерелаSebhat, Woldemichael. "Valorisation de la lignine par catalyse hétérogène en condition sous-critique en milieux aqueux et eau/alcool." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10273/document.
Повний текст джерелаLignin is a macromolecule comprising lignocellulosic biomass, and is composed of propylphenyl units. Lignin is produced in large amounts by the paper industry when cellulose is isolated from biomass. Currently, its value is largely limited to source of energy and heat in recovery boilers. Nonetheless lignin can be an alternative source of aromatics if depolymerized effectively. The present work focuses on the transformation of lignin into aromatic building blocks using sub-critical water and mixtures of water/alcohols (225°C and 40-80 bar). Preliminary studies were carried out in a batch reactor; water was used as a solvent for the conversion of a Kraft lignin in the presence of catalysts (Pt, Pd, Ru on Al2O3, TiO2, ZrO2). The Pd/ZrO2 catalyst gave the highest yield of identified phenols with 2% in 3 hours. To improve the conversion of the lignin by minimizing condensation reactions between phenolic units, the water was replaced with a mixture water/alcohol (ethanol, methanol, isopropanol). The combination water/isopropanol without catalyst allowed us to increase the yield of identified phenols to 5%. The results obtained in batch reactor were extrapolated to a trickle-bed reactor. Even though the water/isopropanol mixture gave the best results in batch reactor, the implementation on a continuous reactor proved to be complex (formation of solids clogging the reactor). The use of a water/ethanol mixture prevented this problem and a yield in guaiacol of up to 1 % was obtained. Ethanol helps stabilize unstable building blocks by alkylation and esterification. This is evidenced by the NMR and chromatographic analysis
Verrier, Thomas. "Function and plasticity of NKp46 expressing innate lymphoid cells." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC173/document.
Повний текст джерелаGroup 3 Innate Lymphoid cells (ILC3) actively maintain mucosal homeostasis through the production of Interleukin-22 (IL-22). ILC3 encompass 2 major populations, LTi (« Lymphoid Tissue inducer »), characterized by the expression of the chemokine receptor CCR6, and ILC3 that express the transcription factor T-bet, which include a population expressing the surface marker NKp46, a receptor originally used to identify group 1 ILC (ILC1). ILC1 plays a major role in the defense against intracellular pathogens and anti-tumoral responses. Three major ILC1 populations have been identified: the cytotoxic lymphocytes « Natural Killer » (NK or ILC1b), which largely rely for on the transcription factor Eomes their generation and express the integrin CD49b; hepatic and intestinal ILC1 that depends on the T-bet transcription factor and express CD49a (ILC1a); and a population that expresses CD49a and CD49b (ILC1ab) and populates the salivary gland and the uterus, which is independent of the transcription factor Nfil3. My work aimed to understand the biology of NKp46 expressing ILC, as well as factor involved in their development, maturation and function. The major part of my work focuses on NKp46+ ILC3. First, we demonstrate a major role for the chemokine receptor CXCR6 in their localisation in the lamina propria villi (Satoh-Takayama et al. 2014). Second, I showed that NKp46+ ILC3 could lose NKp46 expression (Verrier et al. 2016). Induced by TGFβ, this loss of expression was associated with higher IL-22 production and by the acquisition of markers identifying LTi (CCR6, MHC-II), demonstrating NKp46+ ILC3 plasticity. Finally, in collaboration with Rachel Golub’s group, we confirmed a putative role for Notch-signaling in this plasticity (Chea et al. 2016). In this manuscript, I will discuss the development and the heterogeneity of ILC3, ILC1a, ILC1b and ILC1ab. All the results I generated support a dynamic vision of ILC biology, which reflects how they adapt in response to environmental cues. By characterizing the different actors involved in this dynamic process, my work could be used to design therapies aiming at controlling the equilibrium between these different populations in diverse pathologies such as cancer, viral infection, or intestinal diseases
Parmentier, Jean-Francois. "Extension du formalisme Euler/Euler pour la simulation des lits fluidisés de particules du groupe A dans la classification de Geldart." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0121/document.
Повний текст джерелаThis work aims to increase the predictivity of the two-fluid model in gas-solid fluidized beds of Geldart A particles. The first part deals with the integration of physical phenomena into the two-fluid model: shear-induced collisions, lubrication between particles and inter-particular forces. The second part deals with the practical resolution of the two-fluid model using numerical codes. It is shown that bed expansion for Geldart A particles have a strong dependance on the mesh size used to compute the flow, leading to a major overestimation. The filtered approach is used and points up the filtered drag as the key of the problem. Two subgrid drag models are proposed and tested on both academic and laboratory configurations
TERENZI, Alessandro. "Innovative Digital Signal Processing Methodologies for Identification and Analysis of Real Audio Systems." Doctoral thesis, Università Politecnica delle Marche, 2021. http://hdl.handle.net/11566/287822.
Повний текст джерелаMany real word audio systems exist, each has its own characteristics but almost all of them can be identified from the fact that they are able to generate or modify a sound. If a natural or artificial system can be defined as a sound system, then it is possible to apply the techniques of digital signal processing for the studying and the emulation of the system. In this thesis, innovative methodologies for digital signal processing applied to real audio systems will be discussed. In particular, three different audio systems will be considered: the world of vacuum-based non linear audio devices with particular attention to guitar and hi-fi amplifiers; the room acoustic environment and its effect on the sound propagation; and finally the sound emitted by honey bees in a beehive. Regarding the first system, innovative approaches for the identification of the Volterra series and Hammerstein models will be proposed, in particular an approach to overcome some limitation of Volterra series identification. The application of a sub-band structure to reduce the computational cost and increase the convergence speed of an adaptive Hammerstein model identification will be proposed as well. Finally, an innovative approach for the measurement of several distortion parameters using a single measure, exploiting a generalized Hammerstein model, will be presented. For the second system, the results of the application of a multi-point equalizer to two different situations will be exposed. In particular, in the first case, it will be shown how a multi-point equalization can be used not only to compensate the acoustical anomalies of a room, but also to improve the frequency response of vibrating transducers mounted on a rigid surface. The second contribution will show how a sub-band approach can be used to improve the computational cost and the speed of an adaptive algorithm for a multi-point and multi channel equalizer. At the end, the focus will be on a natural sound system, i.e., a honey bees colony. In this case, an innovative acquisition system for honey bees sound monitoring will be presented. Then, the approaches developed for sound analysis will be exposed and applied to the recorded sounds in two different situations. Finally, the obtained results, achieved with the application of classification algorithms, will be exposed. In the final part of the work some minor contributions still related to signal processing applied to real sound systems are presented. In particular, an implementation of an active noise control system is discussed, and two algorithms for digital effects where the former improves the sound performances of compact loudspeakers and the latter generates a stereophonic effect for electric guitars are exposed.
Nassor, Alice. "Domain decomposition method for acoustic-elastic coupled problems in time-domain. Application to underwater explosions." Electronic Thesis or Diss., Institut polytechnique de Paris, 2023. http://www.theses.fr/2023IPPAE015.
Повний текст джерелаThis work addresses global-in-time domain decomposition approaches for the numerical solution of transient fluid-structure interaction problems. To determine an optimal algorithm, we first study the solvability for the transient acoustic and elastodynamic problems with Robin and Neumann boundary conditions. We state solvability results along with the different space-time regularities of the solutions. We also study the solvability for the transient coupled elastodynamic-acoustic problem. Using on these mathematical results we then propose a global-in-time iterative algorithm based on Robin boundary conditions for the coupled elastodynamicacoustic problem and we prove its convergence.These results are leveraged to design a computational methodology by coupling two efficient numerical methods. The fluid response is formulated in the discrete-time domain, using a Z-BEM approach that combines (i) a boundary element method (BEM) accelerated with hierarchical matrix implemented in the Laplace domain and (ii) a convolution quadrature method. The structure response is modelled using the finite elements method. We thus propose a global-in-time iterative coupling with guaranteed convergence, which enables the use of two distinct numerical methods in a non-intrusive manner.Several improvements are then explored: an acceleration method is implemented and a high-frequency approximation is proposed to improved the Z-BEM efficiency. A second iterative global-in-time coupling based on an acoustic-acoustic interface is then proposed and its convergence is also proved. This coupling enables the addition of non linear effects due to the cavitation phenomenon to derive a more realistic fluid model. The Z-BEM is lastly adapted using the method of images to take a free surface into account.This method is applied on fast-time problems of acoustic shock wave scattering by submerged elastic structures and enables to simulate realistic configurations from naval industry
Mavaleix-Marchessoux, Damien. "Modelling the fluid-structure coupling caused by a far-field underwater explosion." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAE012.
Повний текст джерелаSubmarines must withstand the effects of rapid dynamic loads induced by underwater explosions. Due to the very high cost of experimental campaigns, numerical simulations are very important. A remote underwater explosion is a complex event that has two distinct effects: it sends a shock wave, then creates an oscillating gas bubble that sets water in slower motion. The two phenomena have quite different characteristics and time scales. In this work, we consider remote enough underwater explosions so that (i) the presence of the submarine only marginally affects the explosion, and (ii) there is a temporal separation of the two phenomena, as experienced by the ship. Under these conditions, our overall goal is to design, implement (in the context of high performance computing) then validate a computational methodology for the fluid-structure interaction problem, taking into account both phenomena. With this aim, we first study the two perturbations without considering the submarine, to propose appropriate modelling and numerical methods. Then, we design a fast boundary element (BEM) procedure, based on the combination of the convolution quadrature method and an original empirical high frequency approximation. The procedure allows to efficiently simulate 3D rapid transient wave propagation problems set in an unbounded domain, and shows advantageous complexity: O(1) in regards to the time discretisation and O(N log N) for the spatial discretisation. Finally, we implement adequate finite element/boundary element (FEM/BEM) coupling strategies for the shock wave fluid-structure interaction phase (linear acoustics) and that of the gas bubble (incompressible flow). The overall procedure, validated on academic problems, provides very promising results when applied on realistic industrial cases
Goula, Agathi Vasiliki. "Implication des lésions oxydantes et du mécanisme de réparation par excision de base dans la sélectivité tissulaire de l'instabilité somatique des répétitions CAG dans la maladie de Huntington." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00868694.
Повний текст джерелаChevrier, Solène. "Development of subgrid models for a periodic circulating fluidized bed of binary mixture of particles." Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/19905/1/CHEVRIER_Solene.pdf.
Повний текст джерелаHuvet, Chloé. "D’Un nouvel espoir (1977) à La revanche des Sith (2005) : écriture musicale et traitement de la partition au sein du complexe audio-visuel dans la saga Star Wars." Thesis, Rennes 2, 2017. http://www.theses.fr/2017REN20048.
Повний текст джерелаThe scores of the Star Wars saga, a gigantic dischronic cycle spanning over a long period of twentyeight years, are all composed by John Williams, a unique configuration in cinema history. This compositional consistency should theoretically establish the two trilogies (1977-1983 and 1999-2005) as a coherent and unified whole, especially as George Lucas considers the six episodes as one single entity. Nevertheless, the hexalogy’s musical unity and the existence of a Star Wars musical signature are far from self-evident, instead taking the form of an ideal devoid of real, solid foundations.By adopting a comparative cross-disciplinary approach and by resorting to different scales of analysis (episode, trilogy, saga), this dissertation aims to show in which ways the musical material, Williams’ compositional practice as well as the use and integration of the score within the audiovisual complex are subjected to profound transformations between the two trilogies. This research also questions how and to what extent these changes in Williams’s writing and the score’s treatment in the different episodes are related to the mutations of film techniques, especially those of the digital age.Drawing on unreleased hand-written sources and personal interviews conducted with Williams’ main orchestrator, Conrad Pope, and his music editor, Kenneth Wannberg, this dissertation implements a firm interdisciplinarity at the intersection of musical analysis, cinema and technology history
Prnka, Jiří. "Výpočtové modelování hluku v kabině letounu VUT 100 Cobra." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229032.
Повний текст джерелаKamrath, Matthew. "Extending standard outdoor noise propagation models to complex geometries." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1038/document.
Повний текст джерелаNoise engineering methods (e.g. ISO 9613-2 or CNOSSOS-EU) efficiently approximate sound levels from roads, railways, and industrial sources in cities. However, engineering methods are limited to only simple box-shaped geometries. This dissertation develops and validates a hybrid method to extend the engineering methods to more complicated geometries by introducing an extra attenuation term that represents the influence of a real object compared to a simplified object.Calculating the extra attenuation term requires reference calculations to quantify the difference between the complex and simplified objects. Since performing a reference computation for each path is too computationally expensive, the extra attenuation term is linearly interpolated from a data table containing the corrections for many source and receiver positions and frequencies. The 2.5D boundary element method produces the levels for the real complex geometry and a simplified geometry, and subtracting these levels yields the corrections in the table.This dissertation validates this hybrid method for a T-barrier with hard ground, soft ground, and buildings. All three cases demonstrate that the hybrid method is more accurate than standard engineering methods for complex cases
Moreau, Luc. "Comportement d'un glacier tempere sur son lit rocheux. Vitesses de glissement, hydrologie et hydrographie. Etude effectuee au sein du site sous-glaciaire d'emosson glacier d'argentiere, massif du mont-blanc, france." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10202.
Повний текст джерелаKerfai, Syrine. "Etude d'un procédé chromatographique d'échange d'ions pour la séparation de la ribulose 1,5-diphosphate carboxylase (Rubisco) dans le cadre de la valorisation d'un sous produit agricole." Thesis, Toulouse, INSA, 2011. http://www.theses.fr/2011ISAT0014/document.
Повний текст джерелаBiological raw material derived from bio-refinery processes, is often considered a source of pollution but it seems also to be a promising alternative to potential material recovery. The development of suitable processes for handling such complex biological material has so many concerns. Green juice produced from mechanical dehydration of Alfalfa (Medicago sativa) is an excellent source of protein with high nutritional quality. Ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) is the most abundant protein in the green juice, with potential applications in many fields, such as human nutrition, pharmaceuticals, environmental… The aim of this study is to isolate and recover Rubisco produced from an industrial alfalfa green juice, by ion exchange chromatography process. First of all, a qualitative and quantitative analytical method was developed to provide reliable information about Rubisco content monitoring in the separation process. In a second step, the separation process was performed in fixed and expanded bed, using the anion exchanger Q Hyper Z. In both cases, the effect of the dilution of the green juice on the dynamic capacity of the columns was studied. The results showed that the dynamic capacity retention was similar in both columns to those reported in literature. After elution step, Rubisco was concentrated 21 times and produced with high level of purity. Furthermore, kinetic of ion exchange study was initiated. Despite the large size of the protein (560 kDa), steric limitations to mass transfer were not very significant when compared to those of conventional small proteins. The support Q Hyper Z showed an excellent affinity for the protein recovery. Finally, a first theoretical investigation has been conducted for understanding the retention mechanism between the protein and the separation column. This study shows the importance of taking into account the presence of other bio-molecules in order to perform the retention of Rubisco, perhaps even more than that of salts
Hydén, Malin. "Sanning och konsekvens : En studie av den estetiska intentionen hos tre verk av Felix Gmelin." Thesis, Södertörn University College, School of Culture and Communication, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-3075.
Повний текст джерелаYou could say that the Swedish artist Felix Gmelin in his art uses media to get closer or further away from what we consider to be the reality and also truth. The purpose of this study is to discuss what this means for the intention of his art works. The starting point is my own aesthetic experience of his painting and the installations A Gentleman’s agreement (1996), Farbtest, Die Rothe Fahne II (2003) and Tools and Grammar 2.5 (2007). Each of these works of art consists of different kinds of prefabricated material such as articles, films and documents. These kinds of material are often considered to stand in the way of the aesthetic experience, maybe because they are supposed to be closer to reality and therefore to truth. The thesis of this study is that the truth in art is inscribed in the aesthetic framework of each art piece and also in the technical support it uses. If for example the support consists of an investigative journalist’s documentary research, in Rosalind Krauss’ description, the truth might be found in the authenticity of the documentary material. If the technical support has to do with sampling instead, as in the re-use of existing materials to create new works of art, the truth can probably not be found in the different pieces of material but in the work ofart in itself. It does not matter then if the different pieces of material it consists of is traditionally considered unaesthetic. The conclusion of this study is that Gmelin’s Gentleman’s agreement, Farbtest, Die Rothe Fahne II and Tools and Grammar 2.5 actually discuss what truth is and if there is an aesthetic truth.
Examensarbetet består dels av en vetenskaplig rapport (se Huvudtitel och Abstract), dels av en vetenskaplig artikel (se Alternativ titel).
Tozy, Rita. "Compréhension et optimisation du traitement biologique anaérobie des coproduits de l’industrie sucrière." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC075.
Повний текст джерелаThe growing international demand for energy and water constitutes a significant challenge for modern industry. Integrated in a sugar and ethanol factory, anaerobic digestion can provide an environmentally friendly solution by using organic matter co-products to provide energy that can partially cover the factory’s needs. The purpose of this doctoral thesis is the study of the anaerobic digestion of sugar beet pulps and distillery vinasses. We used a multiscale approach to achieve the two main objectives: understanding the biological phenomena involved and analyzing the technological problems that can occur in the digesters. We first demonstrated the feasibility of the anaerobic digestion of beet pulps in a continuously stirred tank reactor (CSTR) without water addition. Thermophilic digestion was effective and we achieved a high degradation of pulps with satisfactory biogas yields. The thermophilic process could operate stably up to an organic loading rate of 5 to 5,9 kg VS.m-3.d-1. The biodegradability of pulps was very high and allowed to obtain a VS destruction of 88,1% with a specific methane production of 0,353 Nm3 CH4.kg-1 VS. Next, the mesophilic anaerobic digestion of vinasses revealed the limits of the CSTR process for the treatment of this high strength distillery wastewater. The maximum loading rate reached was between 2 and 3 kg COD.m-3.d-1, with a specific methane production of 0,344 Nm3 CH4.kg-1 VS. However, the accumulation of volatile fatty acid salts, even at low organic loading rates, indicated an imbalance between acidogenic and methanogenic microflora. From a biological perspective, we assumed that the high salt concentration of vinasses (up to 41,3 mS/cm) is the main obstacle to the development and activity of microorganisms, as a two-reaction model (AM2) showed low specific growth rate of methanogens. The partial extraction of salts by electrodialysis allowed to remove a part of this inhibition, while their dilution led, at equivalent organic loading rate, to the reduction of the residence time by a factor 4. This was achieved without decreasing methane yield, while also reducing concentrations of acetate and propionate in the digester. To enable process intensification, biomass recycling in the digester, after the centrifugation, was tested to compensate for their low specific growth rates; loading rates reached 7 kg COD.m-3.d-1. We subsequently put in place a strategy for digesters control, to ensure effective monitoring. Finally, we had to characterize the digestates and to consider their different treatment paths. (evapoconcentration, solid / liquid separation, ...) before final valorization. For the industrial scale up, we envisage the successive treatment of the coproducts according to their availability: pulps during the sugar campaign and then vinasses in the intercampaign. As such, we also studied the transition periods and demonstrated the feasibility of a mixed feed, without reducing the loading rate. For such a project, we would choose mesophilic temperature conditions, more favorable for the treatment of a product like vinasses. A system for biomass recycling, whose efficiency was demonstrated, must be installed when the vinasses are treated. The system needs to be compatible with the treatment of the two substrates proposed, for example centrifugation or filtration
Tournier, Martin. "Caractérisation et modélisation de l’habitat physique et biologique vertical des mammifères marins grands plongeurs." Thesis, La Rochelle, 2022. http://www.theses.fr/2022LAROS018.
Повний текст джерелаDeep-diving mammals evolve within a tri-dimensional environment where the physical and biological conditions vary. These variations can influence their utilization of the vertical dimension. This Ph.D. thesis focuses, first, on acoustic signal analysis, the signal being sampled by a miniaturized echo-sounder deployed on southern elephant seals, and aims at biologically describing the water column. Through that acoustic signal, mid-trophic level organisms have been observed, as well as important particle export. Second, to determine the influence of dynamic environmental variables, such as temperature or salinity, on the vertical position of elephant seals and Blainville’s beaked whales, we proposed a new methodology suitable for using environmental predictors described in the form of profiles by using functional analysis approaches. When using the variables obtained in situ by elephant seals, we show that the environmental profiles influence the depth of the dives. However, the model tends to underestimate the predicted depth of animals, mainly in areas where high oceanic dynamics are observed. When using the same approach on the restricted beaked whales’ dataset, and by using environmental variables obtained from oceanographic models, we did not observe any impact of the environmental conditions on the whales’ water column use. This methodological approach could allow the integration of the vertical dimension toward the development of tri-dimensional habitat modelling under the conditions that the spatial and temporal resolutions of the dataset are adequate
Özel, Ali. "Simulation aux grandes échelles des lits fluidisés circulants gaz-particule." Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0090/document.
Повний текст джерелаEulerian two fluid approach is generally used to simulate gas-solid flows in industrial circulating fluidized beds. Because of limitation of computational resources, simulations of large vessels are usually performed by using too coarse grid. Coarse grid simulations can not resolve fine flow scales which can play an important role in the dynamic behaviour of the beds. In particular, cancelling out the particle segregation effect of small scales leads to an inadequate modelling of the mean interfacial momentum transfer between phases and particulate shear stresses by secondary effect. Then, an appropriate modelling ac counting for influences of unresolved structures has to be proposed for coarse-grid simu-lations. For this purpose, computational grids are refined to get mesh-independent result where statistical quantities do not change with further mesh refinement for a 3-D peri-odic circulating fluidized bed. The 3-D periodic circulating fluidized is a simple academic configuration where gas-solid flow conducted with A-type particles is periodically driven along the opposite direction of the gravity. The particulate momentum and agitation equations are filtered by the volume averaging and the importance of additional terms due to the averaging procedure are investigated by budget analyses using the mesh independent result. Results show that the filtered momentum equation of phases can be computed on coarse grid simulations but sub-grid drift velocity due to the sub-grid correlation between the local fluid veloc- ity and the local particle volume fraction and particulate sub-grid shear stresses must be taken into account. In this study, we propose functional and structural models for sub- grid drift velocity, written in terms of the difference between the gas velocity-solid volume fraction correlation and the multiplication of the filtered gas velocity with the filtered solid volume fraction. Particulate sub-grid shear stresses are closed by models proposed for single turbulent flows. Models’ predictabilities are investigated by a priori tests and they are validated by coarse-grid simulations of 3-D periodic circulating, dense fluidized beds and experimental data of industrial scale circulating fluidized bed in manner of a posteriori tests
Rapetto-Labidi, Astrid. "Etude de la délignification en continu du bois de peuplier en milieu basique : cinétique et chimie des procédés ; caractérisation des lignines extraites." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0083.
Повний текст джерелаPavier, Claire. "Oxypropylation de la pulpe de betterave à sucre et utilisation des polyols obtenus pour la préparation de nouveaux matériaux polyuréthanes." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0041.
Повний текст джерелаHuang, Deshau. "Heat transfer in a sound-assisted fluidized bed /." Diss., 2002. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3073975.
Повний текст джерелаChen, Huan-Yung, and 陳冠罃. "Application of fuzzy theory to queen bee rearing and breeding monitor system with sound feature." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/d5q3ch.
Повний текст джерела國立屏東科技大學
工業管理系所
106
The artificial rearing and breeding of the queen bee in the honey industry is a core technology of the beekeeping industry. The work of rearing and breeding of the queen bee is usually conducted once a year; it concerns the bees’ honey extraction and pollen mining performance, and it is one of the most important jobs of the beekeepers. This work will incorporate the sound sensors inside the beehives and monitor the progress of rearing and breeding the queen bees using sound at all times. This work applies the trapezoidal membership function of the fuzzy theory to monitor a system of queen bee rearing and breeding. This work would record the sound of honey collection, by using the frequency spectrum map to analyze the frequencies of not having a queen bee, the new queen bee that has not mated, and the new queen bee that has already mated. The process of rearing and breeding the queen bee in each beehive can be instantaneously monitored, in order to enhance the effectiveness of rearing and breeding the queen bee by the bees. This would help to enhance the promotion of the domestic beekeeping industry.
"Safe and Sound: A Resource Guide for Music Theater Technique and Literature." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.51786.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Music 2018
Joseph, James Adlai. "Precision Measurement of the Sound Velocity in an Ultracold Fermi Gas Through the BEC-BCS Crossover." Diss., 2010. http://hdl.handle.net/10161/2367.
Повний текст джерелаA trapped Fermi gas near a collisional resonance provides a unique laboratory for testing many-body theories in a variety of fields. The ultracold Fermi gas produced in our lab is comprised of the lowest two spin states of $^6$Li. At 834 G there is a collisional or Feshbach resonance between the two spin states. The scattering length between trapped atoms of opposing spins far exceeds the interparticle spacing of the gas. On resonance, a strongly interacting, unitary, Fermi gas is created which exhibits universal behavior. The unitary Fermi gas is a prototype for other exotic systems in nature from nuclear matter to neutron stars and high temperature superconductors.
For magnetic fields less than 834 G the scattering length is positive, and pairs Fermi atoms can form molecular dimers. These dimers, comprised of two fermions, are bosons. At ultracold temperatures the molecular bosons populate the lowest energy level and form a Bose Einstein Condensate (BEC). For magnetic fields greater than 834G the scattering length between fermions in opposing spin states is negative, like Cooper pairs formed between electrons in a superconductor. The Bardeen, Cooper, and Shriefer (BCS) theory was developed to describe the pairing effect in the context of superconductors. In our experiment we produce an ultracold unitary gas. By tuning the magnetic field to either side of the Feshbach resonance we can transform the gas into a weakly interacting BEC or BCS superfluid. Therefore, the region near a Feshbach resonance is called the BEC-BCS crossover.
This dissertation presents a precision measurement of the hydrodynamic sound velocity in an ultracold Fermi gas near a Feshbach resonance. The sound velocity is measured at various magnetic fields both above and below resonance. Moreover, we are able compare our measurements to theoretical descriptions of hydrodynamic sound propagation. Further, our measurement of sound velocity exactly reproduces the non-perturbative case, eliminating the need to consider nonlinear effects. At resonance the sound velocity exhibits universal scaling with the Fermi velocity to within 1.8\% over a factor of 30 in density. In a near zero temperature unitary gas the average sound velocity at the axial center was measured, $c(0)/v_F$ = 0.364(0.005), as well as the universal constant, $\beta$ = -0.565(0.015). The measurement of sound velocity in an ultracold gas throughout the BEC-BCS crossover provides further evidence of the continuous connection between the physics of the BEC, unitary, and BCS systems.
Dissertation
Kirkham, Airlie Jane. "An aural analysis of bel canto: traditions and interpretaitons as preserved through selected sound recordings." Thesis, 2010. http://hdl.handle.net/2440/65016.
Повний текст джерелаThesis (M.Mus.) -- University of Adelaide, Elder Conservatorium of Music, 2010
簡美秀. "A Role Exploration of Da Bei Zhou Sound Therapy in Compassion Repentance." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15242471454334477635.
Повний текст джерела佛光大學
生命與宗教學系
102
Da Bei Zhou brings people calm and joy. Every temple has Great Compassion Puja very often and has many Buddhists attend. Buddhists make themselves calm and relieved by chanting Da Bei Zhou. This phenomenon shows that this issue is very important in Buddhism. Therefore, this study will focus on the role of Da Bei Zhou in Great Compassion Puja and its sound wave influence. In literature review, the study discusses the relationship between Great Compassion Puja and Da Bei Zhou, and also tries to find out the influence of Da Bei Zhou to Great Compassion Puja and Buddhists. Besides, by studying the sound wave and therapy, the study aims to find out the function and meaning that Da Bei Zhou brings to Buddhists. After the literature review, the study uses questionnaire survey and analyzes its results. The main findings are listed as below. 1.The ritual doesn’t exist if the ritual doesn’t come with chanting. Buddhism conveys its dharma by chanting. Therefore, chanting Da Bei Zhou is one of the key elements. 2.Buddhist music therapy is not usual physical therapy. It is developed from Buddhist culture. It doesn’t cure disease with science nor medial theory. Buddhist music therapy is based on Buddhism dharma and works with spiritual practice. It’s not just physical maintenance; instead it’s more about the experience and practice of life. Based on the results above, the study suggests that we can have the public and Buddhists know Da Bei Zhou better by holding more community lectures. In that way, for people who love to attend pujas, they can purify themselves with respected spirits and the sound therapy function of Da Bei Zhou will be practiced.
Liu, Yen-Ming, and 劉彥銘. "Simulation of the Sound Pressure Level of a Miniature Loudspeaker by Coupled BEM-FEM." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/39566467531771946053.
Повний текст джерела逢甲大學
電聲碩士學位學程
99
As one of the crucial criteria to judge its performance, the sound-pressure-level (SPL) of a loudspeaker is mostly modeled by the equivalent-circuit method (ECM) or the finite element method (FEM). Despite the extensive applications of the ECM in this modeling, its SPL modeling at the mid-high to high frequencies, ranging about from 1k to 20k (Hz), is not so ideal due to modal splits of the membrane. On the FEM modeling, considerable amounts of computational efforts shall be required due to the 3D modeling of unsymmetrical acoustic field. For this, this has been a serious issue in the industry that pertinent researches have been endeavoring to resolve. The present research employs the approach of coupled FEM/boundary element method (BEM) to effectively improve the SPL modeling of a sample unit at the mid-high to high frequencies. The advantage of such an approach lie in incorporating the both benefits of the FEM and the BEM, considered to be effective for modeling the membrane vibration and the associated acoustic field, respectively. This coupled modeling, on one hand, adopts ANSYS to simulate the modal vibration of the membrane and, on the other hand, applies the BEM-based software, Virtual Lab, to simulate the corresponding sound field using the boundary condition (normal velocity gradients of the membrane) exported from the ANSYS analysis. For verification, the sample unit was experimented in an anechoic chamber for recording its SPL curve, followed by comparing with the simulated result. Additionally, the SPL curves at different field points with various phase angles were also experimented and simulated using the coupled approach. From the analyses and comparison, it is found that the SPL modeling by the present approach is more accurate for mid-high to high frequencies as compared with the traditional ECM approach and, moreover, more effective than the FEM modeling. This research provides a more accurate and effective approach for modeling the SPL curve of loudspeakers, based on which the engineer may tailor the loudspeaker design by reduced efforts and time. By the present approach, it is very easy to acquire the SPL of a field point of interest in space. This expedition of such simulation and analysis has laid the great potential of its application to model the overall SPL of multiple loudspeakers with various phase angles, being crucial for a pro-designed audiovisual studio or auditorium. Due to the various phase angles, the ECM cannot be applied for such modeling, and neither is the FEM due to the massive computation loads. In all, the thesis has proposed a feasible and expedient approach for accurately and effectively modeling the SPL of loudspeakers, considered to possess great potential for extensive applications in modeling a complicated electro-acoustic system.
Yang, Ming-Ta, and 楊明達. "Optimization of MEMS Microphone Size Parameters by BEM Sound Field Analysis and Taguchi Method." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/14336490688670819571.
Повний текст джерела國立中山大學
機械與機電工程學系研究所
99
Since the micro-electro mechanical system microphone, MEMS microphone, has the advantages of superior sound quality, low power consumption, higher temperature resistance and anti-noise ability in used. The researchers therefore have studied the functions of MEMS microphone since 1980s. The MEMS microphones is applied as the part of 3G mobile phone in the market. Though the functions of microphone are improved by manufacturing process technique and new material designed, this study tends to provide a new, low-cost and rapid design idea to gain the performance in chamber of microphone. Taguchi method and BEASY software, which is boundary element method, are combined to evaluate the results of the design in sound field. Taguchi method is a famous method in industrial design to find out relations between system parameters and chamber size. BEASY is a tool for sound field analysis in the research. The result from Taguchi method appears the sound pressure level gain about 2.2 dB to 2.4 dB due to the change of microphone chamber size only. It is also interested in studying the optimization design for position of microphone. It is displayed that the location of port is closer to the boundary of chip will also increase about 0.3 dB to 0.6dB sound pressure level in sound field. The higher frequency of sound source will also create larger sound pressure level at two corners on the port.