Dissertations / Theses: 'EER transmissions'

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Teoh, Su Wooi. "The roles of pars flaccida in middle ear acoustic transmission." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39751.

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Miller, Antonio John. "Using otoacoustic emissions to measure the transmission matrix of the middle-ear." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37979.

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Thesis (S.M.)--Harvard-MIT Division of Health Sciences and Technology, 2006.
Includes bibliographical references (leaves 39-41).
Here we describe an experimental method for measuring the acoustic transmission matrix of the middle-ear using otoacoustic emissions. The experiment builds on previous work that uses distortion product otoacoustic emissions (DPOAEs) as an intracochlear sound source to drive the middle-ear in reverse. This technique eliminates the complications introduced by needing to place an acoustic transducer inside the cochlea. Previous authors have shown how the complete 4x3 system response matrix, with its 12 unknowns, can be simplified to a 2x2 transmission matrix by de-coupling the middle-ear cavity and assuming the cochlear fluids are incompressible. This simplified description of middle-ear mechanics assumes that the input-output response at the tympanic membrane and stapes footplate is linear, one dimensional and time invariant. The technique allows for estimating the acoustic pressure and volume velocity at the tympanic membrane and the volume velocity of the stapes footplate, in both the forward and reverse direction, and under different boundary conditions at the stapes. The technique was applied to deeply anesthetized cats with widely opened middle-ear cavities over a frequency range of 200Hz to 10kHz. Results on three animals are reported and generally agree with previous data and a published middle-ear model.
by Antonio John Miller.
S.M.

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Voss, Susan E. (Susan Elizabeth). "Effects of tympanic-membrane perforations on middle-ear sound transmission : measurements, mechanisms, and models." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9921.

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Heidrych, Paulina. "Novel interaction partners for Otoferlin, a functional member of acoustic transmission in the inner ear /." Tübingen, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000253078.

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Oliveira, Ana L. "Host preference profile in an area of Eastern Equine Encephalitis (EEE) virus transmission in Alabama." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2010. https://www.mhsl.uab.edu/dt/2010p/oliveira.pdf.

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Lomas, Kathryn. "The auditory system of the Auckland tree weta (Hemideina thoracica): sound transmission through an ensiferan ear." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/8350.

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The aim of this thesis is to examine the structure and function of the auditory system of the Auckland tree weta Hemideina thoracica, an iconic endemic insect of New Zealand (Orthoptera, Anostostomatidae). H. thoracica hear in a narrow frequency range relevant to conspecific communication. The thresholds and firing rates of the tympanal organ receptors and auditory interneurons were measured. Results showed that males responded most strongly to frequencies relevant to intraspecific communication indicating that acoustic communication by male weta may have a more important role in intrasexual competition rather than mate choice. Weta hear with typical ensiferan prothoracic tibial ears located on each foreleg. Each ear comprises three functional parts: two equally sized tympanal membranes, an underlying system of highly modified tracheal chambers, and the auditory sensory organ, the crista acustica. Weta have the thickest and largest membranes so far described in any insect. It is expected that a membrane of this thickness would have low impedance. However, Hemideina have extremely sensitive hearing. microscanning laser Doppler vibrometry was used to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotised region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the weta, an unusual example of insect tympana acting as a narrow bandpass filter. To determine what internal mechanisms in the weta are responsible for fine-scale frequency discrimination, measurements taken from high-resolution three-dimensional models of the complete weta ear, combined with vibration analysis of the tympanal deflections in response to sound waves, to construct a theoretical model of sound transmission. The combination of using advanced histological techniques and three-dimensional modelling has allowed me to uncover a new structure (Olivarus) within the auditory system of weta that has not previously been described in any other insect hearing systems. Mass spectrometry analysis of the surrounding liquid has revealed this structure sits within lipids of an unknown type and this structure may be synthesizing the lipids. Three possible theories are presented of the role in hearing played by the Olivarus and lipid and suggest iv that a simple ancient insect auditory system is possibly homologous to that of the mammalian basilar membrane.

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Wong, Man Fai. "A novel compact microstrip type composite right/left handed transmission line (CRLH TL) and its applications /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-ee-b23750467f.pdf.

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Thesis (M.Phil.)--City University of Hong Kong, 2009.
"Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Master of Philosophy." Includes bibliographical references.

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Berling, Holm Katarina. "The Chorda Tympani Nerve : Role in Taste Impairment in Middle Ear Disease and after Ear Surgery." Doctoral thesis, Uppsala universitet, Centrum för klinisk forskning, Västerås, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-316591.

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The chorda tympani nerve, also known as the taste nerve, runs uncovered through the middle ear cavity, a localization that exposes the nerve to pathological processes and surgical trauma in the middle ear. People operated on for otosclerosis tend to complain more about postoperative taste disturbances than those operated on for chronic otitis media. It has been suggested that this difference may be explained by gradual deterioration of chorda tympani nerve function caused by chronic otitis media infection and that further impairment caused by surgery is less noticeable in these patients. This thesis aimed to evaluate the function of the chorda tympani nerve, the effects of middle ear disease on taste and complications resulting from ear surgery for chronic otitis media or otosclerosis. This information will help to improve the ear surgeon’s ability to predict the prognosis of iatrogenic taste disturbances in patients with middle ear disease and after ear surgery. Taste was assessed using electrogustometry and the filter paper disc method before and after surgery for chronic otitis media or otosclerosis. Patients also completed questionnaires about symptoms and quality of life. The status of the chorda tympani nerve upon surgical opening of the ear and grading of the trauma to the nerve during the surgery were recorded. The ultrastructure of the chorda tympani nerve from healthy ears and from ears with chronic otitis media was examined. Electrogustometry and the filter paper disc method were evaluated. The results of electrogustometry and the filter paper disc method were highly reproducible, although their correlation was moderate. Patients with chronic otitis media, patients with a more traumatized nerve, female patients and younger patients were more likely to report postoperative taste disturbances. Most of the patients recovered their taste after 1 year. The quality of life study showed only minor changes after surgery. Electron microscopic observations of nerves from ears with chronic otitis media showed signs of structural degeneration, although signs of regeneration, such as sprouting were also observed. This results may explain the recovery of taste postoperatively and indicate that the nerve should be carefully handled during surgery.

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Alwani, Shariman M. N. "Evaluating the effectiveness of the monetary transmission mechanism in Malaysia." online access from Digital Dissertation Consortium access full-text, 2006. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3232094.

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Imtiaz, Jahanzaib. "Route transmission & control applications and Java web services route transmission and control using a Java EE5 web service and a vehicle based mobile device (cellular phone or a PDA with GPS)." Saarbrücken VDM Verlag Dr. Müller, 2007. http://d-nb.info/988696614/04.

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Veaux, Christophe. "Étude de traitements en réception pour l'amélioration de la qualité de la parole : application au GSM." Paris, ENST, 2005. http://www.theses.fr/2005ENST0006.

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Dans les communications radio-mobiles, la qualité de la parole est fortement impactée par les erreurs résiduelles en sortie du décodeur canal. Celles-ci résultent des paquets d'erreurs introduits par le canal radio alors que les contraintes de complexité limitent les performances du codage canal. Parallèlement, ces mêmes contraintes font qu'il subsiste une redondance résiduelle en sortie du codeur de parole. Cette redondance résiduelle fournit une information a priori qui peut être exploitée au niveau du décodeur de parole pour minimiser l'erreur d'estimation des paramètres transmis, ou au niveau du décodeur canal pour minimiser le taux d'erreurs résiduelles. Nous étudions chacune de ces approches ainsi que leur combinaison dans le cas du GSM EFR. Au niveau du décodeur parole, nous modélisons la redondance résiduelle des paramètres du codeur à l'aide de mélanges de gaussiennes ce qui permet de réduire la complexité de l'estimation par rapport aux méthodes existantes et délivre une information plus riche sur la redondance résiduelle. Au décodeur canal, nous améliorons la prise en compte de la redondance résiduelle entre les bits d'une même trame par une technique de prédiction le long des chemins du treillis. Ces approches sont évaluées sur des simulations de transmission par l'algorithme PESQ de mesure objective de la qualité vocale. Le décodeur de parole exploitant la redondance résiduelle apparaît supérieur au décodeur classique du GSM EFR avec masquage d'erreur. En revanche, les performances du décodeur canal exploitant la redondance résiduelle sont sensibles à la correspondance choisie ente les éléments du dictionnaire de quantification et leur étiquetage binaire
In digital mobile radio systems, the speech quality can be severly degraded if the channel decoder produces residual bit errors due to heavy burst errors on the radio path. On the other hand, in most speech coding schemes some residual redundancy remains because of complexity and delay limitations. A solution for improving the speech quality consists in using a priori information based on source residual redundancy at the receiver side. In one approach, a priori information is used at the source decoder to perform optimal estimation of transmitted codec parameters. In another approach, a priori information is used at the channel decoder in oder to minimize the residual bit errors rate. We study both approaches and apply them to the GSM EFR. At the speech decoder level, we model the residual redundancy of speech codec parameters by using Gaussian mixtures. This model reduces the complexity when compared to state-of-art methods and provides a better representation of residual redundancy. At the channel decoder level, we introduce an efficient method to exploit intra-frame bit redundancy during the channel decoding process. In this method, the value of the bit being decoded is predicted from the bits already decoded along the treillis path. These methods are evaluated on simulations of radio transmission by an objective measure of speech quality. In all cases, the performance of the speech decoder using our residual redundancy model turns out to be better than the GSM EFR decoder with standard error concealment procedure. The performance of the channel decoder using residual redundancy is strongly dependent of the index assignment used by the quantifier

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Wanichworanant, Noppadol. "A traffic engineering approach employing genetic algorithms over MPLS networks." online access from Digital Dissertation Consortium access full-text, 2003. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3134009.

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Moulessehoul-Ounnas, Malika. "Conception et mise en oeuvre de l'interface d'acquisition et de transmission d'un réseau de capteurs sans fil : application à la mesure de signaux électrophysiologiques." Thesis, Tours, 2009. http://www.theses.fr/2009TOUR4043.

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Ce travail de thèse consiste en une étude théorique et expérimentale d'un système detransmission à application universelle. Un système de capteurs ou multi-capteurs sans filsdédié à des différentes applications ayant comme point commun, une basse amplitude. Ils'inspire donc des plates forme des réseaux sans fils existant dans le monde technologique.Nous présentons dans ce mémoire les différentes raisons qui expliquent l'intérêt majeursuscité par un tel système, nous aborderons plus profondément une des applications dusystème, à savoir le domaine neurophysiologique. A partir des choix d'architecture et dessimulations expérimentales correspondantes nous relayons étape par étape les différentesphases qui nous ont mené à réaliser les prototypes en tenant en compte les résultats desuns et des autres, pour finir ensuite par une étude comparative des différents prototypesréalisés et des perspectives envisagées
This thesis work is a theoretical and experimental study of a universal applicationtransmission system. A wireless sensor or multi-sensor system dedicated to different low-magnitudeapplications. It is inspired from wireless networks platforms of the moderntechnological world.In this dissertation, the different reasons for the interest aroused by such a system, arepresented, we will more deeply study one of the applications of this system, namely theneurophysiological area. From the choice of the architecture and corresponding experimentalsimulations we will explain, step by step, the different phases which led us to realize theprototypes taking into account the results of each phase, then finally a comparative studyof different prototypes realized and the prospects envisaged

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Cerasani, Umberto. "Modélisation et optimisation d'un émetteur-récepteur faible bruit pour implants cochléaires." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4093/document.

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Les implants cochléaires permettent aux personnes atteintes de surdité profonde de percevoir des sons. La modélisation comportementale de la partie externe de l’implant a été réalisée avec le logiciel Matlab. L’étude du canal de transmission et sa modélisation utilisant des modèles électriques de tissus biologiques a été ensuite effectuée ainsi que l’étude du niveau de bruit introduit par le canal. Deux types de modulations différentes sont réalisés à l’émission chacune nécessitant un oscillateur. L’étude théorique et la création d’un nouveau modèle afin d’évaluer le bruit de phase ont été proposés. L’extraction du jitter à partir du bruit de phase et son impact sur la chaine de réception complète a été estimée. La compréhension précise et la modélisation des différentes parties de l’oreille humaine qui conduisent à la stimulation des terminaisons nerveuses sont décrites. Par la suite nous avons développé un nouveau modèle mécanique de l’organe de Corti et du déplacement des stéréociles, que nous avons validé à l’aide de données provenant d’expériences physiques. La modélisation mathématique de la synapse entre les cellules ciliées et les fibres nerveuses a été réalisée, afin d’obtenir le stimulus électrique relatif à un son perçu quelconque. De plus un nouveau modèle analogique décrivant la propagation de l’information nerveuse a été développé. En se basant sur la spectroscopie d’impédance électrochimique des tissus biologiques, nous avons créé un modèle électrique du fil d’électrodes inséré dans la cochlée
Cochlear implants are used by severely deaf people for partial hearing sensation. Behavioral modeling of the external part of the cochlear implant was first performed using the software Matlab. Then the propagation channel was modeled using electrical analogy of the biological tissues. Noise extraction of the propagation channel was performed in order to obtain the specifications for the RF receiver. Two types of diverse modulations are performed in the transmitter each one requiring an oscillator. The theoretical study and the creation of a new model allowing phase noise estimation is also proposed in this document. Jitter estimation from phase noise was performed and significantly impacted the overall chain transmission, suggesting oscillators blocks optimization. The accurate heterogeneous modeling of the various part of the internal ear leading to auditory nerve excitation was developed. Then a new mechanical equivalent of the organ of Corti and stereocilia displacement was developed and confirmed by physical experiments. The synapse between the hair cells and nerve fibers was mathematically modeled, in order to obtain the electrical stimulus of the auditory nerve associated with a random sound stimulus. Furthermore a new analog model of the nerve fiber information propagation was realized in order to obtain a realistic electrical analogy with nerve fiber depolarization propagation. Based on impedance spectroscopy biological tissue characterization, we proposed a new electrical analogy of the system composed of the electrodes inserted inside the cochlea

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Mo, Tingting. "Coplanar waveguide components and their applications in microwave circuits /." access abstract and table of contents access full-text, 2006. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b21471514a.pdf.

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Thesis (Ph.D.)--City University of Hong Kong, 2006.
"Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy" Includes bibliographical references.

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Bozzolo, Nathalie. "Contribution de la microscopie électronique en transmission analytique à la caractérisation du diamant CVD." Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_BOZZOLO_N.pdf.

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Nos travaux se situent dans le contexte de la caractérisation de la qualité cristalline des films de diamant élaborés par MPCVD sur silicium monocristallin. Nous étudions plus particulièrement, par MET et EELS, la répartition des défauts plans (fautes d'empilement, joints de macles et micromacles) dans les cristaux constituant les films, ainsi que leurs effets sur les clichés de diffraction électronique et sur les spectres de pertes d'énergie. Un soin particulier est apporté à la préparation de lames minces. Des dégâts d'irradiation sont mis en évidence et caractérisés dans le cas des lames amincies par bombardement ionique. L’examen de plusieurs films de microstructures différentes permet de déterminer les conditions d'élimination des défauts plans. Il existe une relation entre la présence défauts plans et le type de faces délimitant les cristaux, que nous avons vérifié pour différentes morphologies cristallines. Cette relation induit une corrélation entre la distribution spatiale des défauts plans et l'évolution de la microstructure en cours de croissance. Les défauts plans se forment uniquement au cours de la croissance suivant les faces 111. Les films textures <100> dont la surface est majoritairement constituée de facettes 100 présentent une qualité cristalline supérieure à toute autre texture. Cette tendance est d'autant plus marquée que l'épaisseur des films considérés est importante. La qualité cristalline la plus élevée que nous ayons observée correspond aux films hautement orientés sur Si(100) pour lesquelles les défauts plans disparaissent totalement des cristaux à partir d'une certaine épaisseur. Cette épaisseur critique correspond au moment ou les faces 100 externes se sont rejointes en cours de croissance. Cette étude nous a conduit à concevoir un programme de simulation des clichés de diffraction. La présence de défauts plans induit des effets spécifiques sur les clichés de diffraction électronique, qui peuvent être simulés grâce à ce programme, et qui sont mis à profit pour localiser des défauts. Une modification de la structure de bande du diamant liée à la présence des défauts est mise en évidence par EELS

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Garcia, Peña Axel Javier. "Optimization of demodulation performance of the GPS and GALILEO navigation messages." Phd thesis, Toulouse, INPT, 2010. http://oatao.univ-toulouse.fr/12022/1/garcia_pena_partie_1_sur_2.pdf.

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The demodulation performance achieved by any of the existing GPS signals, L1 C/A, L2C or L5, is satisfactory in open environments where the available C/N0 is quite high. However, in indoor/urban environments, the C/N0 level of the received signal is often very low and suffers fast variations which can further affect the GNSS messages demodulation. Therefore, since the mass-market applications being designed nowadays are aimed at these environments, it is necessary to study and to search alternative demodulation/decoding methods which improve the GNSS messages demodulation performance in these environments. Moreover, new GNSS signals recently developed, such as GPS L1C and GALILEO E1, must also be considered. These signals aim at providing satellite navigation positioning service in any kind of environment, giving special attention to indoor and urban environments. Therefore, the demodulation performances of the new GNSS signals as they are defined in the current public documents is also analysed. Moreover, new GALILEO E1 message structures are proposed and analysed in order to optimize the demodulation performance as well as the quantity of broadcasted information. Therefore, the main goal of this dissertation is to analyse and to improve the demodulation performance of the current open GNSS signals, specifically in indoor and urban environments, and to propose new navigation message structures for GALILEO E1. A detailed structure of this dissertation sections is given next. First, the subject of this thesis is introduced, original contributions are highlighted, and the outline of the report is presented. Second, this dissertation begins by a description of the current structure of the different analysed GNSS signals, paying special attention to the navigation message structure, implemented channel code and their decoding techniques. In the third section, two types of transmission channel models are presented for two different types of environments. On one hand, an AWGN channel is used to model the signal transmission in an open environments. On the other hand, the choice of a specific mobile channel, the Perez-Fontan channel model, is chosen to model the signal transmission in an urban environment. In the fourth section, a tentative to make a binary prediction of the broadcasted satellite ephemeris of the GPS L1 C/A navigation message is presented. The prediction is attempted using the GPS L1 C/A almanacs data, a long term orbital prediction program provided by TAS-F, and some signal processing methods: spectral estimation, the PRONY method, and a neural network. In the fifth section, improvements to the GPS L2C and GPS L5 navigation message demodulation performance are brought by using their channel codes in a non-traditional way. Two methods are inspected. The first method consists in sharing information between the message inner and outer channel codes in order to correct more received words. The second method consists in using the ephemeris data probabilities in order to improve the traditional Viterbi decoding. In the sixth section, the GPS L1C and GALILEO E1 Open Service demodulation performance is analysed in different environments. First, a brief study of the structure of both signals to determine the received C/N0 in an AWGN channel is presented. Second, their demodulation performance is analysed through simulations in different environments, with different receiver speeds and signal carrier phase estimation techniques.

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Marcrum, Steven [Verfasser], Werner [Akademischer Betreuer] [Gutachter] Hemmert, and Peter [Gutachter] Kummer. "Optimal Primary Tone Levels in Distortion Product Otoacoustic Emissions and the Role of Middle Ear Transmission / Steven Marcrum ; Gutachter: Peter Kummer, Werner Hemmert ; Betreuer: Werner Hemmert." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/114756583X/34.

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Grafström, Ronja. "Vi ta´re på örat : En intervjustudie om folkmusiklärares tolkningar av begreppet gehör." Thesis, Karlstads universitet, Institutionen för konstnärliga studier (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-83298.

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Syftet med denna studie är att utreda vilka kunskaper och färdigheter olika lärare i folkmusik tolkar tillhör begreppet gehör och i detta belysa hur de själva använder sitt gehör i eget musicerande samt i sin undervisning. Tidigare forskning visar att gehör kan betraktas från många olika vinklar; både som metod eller strategi i undervisning och inlärning, som ämne i olika skolformer och som medfödda eller förvärvade kunskaper och färdigheter. Semistrukturerade intervjuer har använts för att insamla data som sedan analyserats tematiskt. Resultatet visar att lärarna delar uppfattningen om att en musiker som lyckas sammanföra musikteoretiska och genrespecifika kunskaper med speltekniska färdigheter i det egna spelet och i musicerande med andra har ett gott gehör. I detta är medvetenhet, reflektion och kommunikation viktiga parametrar. Diskussionen behandlar de viktiga gehörsmässiga kunskaper och färdigheter som informanterna presenterat. Detta i relation till olika skolformers undervisning och hur den sociala kontexten runt den svenska folkmusiken skapar värde i mötet mellan människor och musik.
The main goal with this study is to get closer to an understanding for what knowledge and skills that different teachers in Swedish folk music reads in to the word by-ear learning and/or oral skills as well as to shine a light upon how they use their own oral skills when playing music and when teaching. Earlier studies show that oral skills can be looked upon from different angles; both as a method or strategy in education or learning, as a subject in different forms of schools and as inherited or acquired skills and knowledge. Semi structured interviews has been used to collect data that has been analyzed thematically. The results of the study show that the teachers share the opinion that a musician who successfully is able to combine knowledge of music theory and genre specifics with instrumental technical abilities when playing solo and with others has well developed oral skills. Self awareness, reflection and communication are key elements in this process. In the discussion of the study the different knowledge and skills presented by the teachers are put in relation with how differents schools in Sweden structure their teaching of oral skills. The chapter also discusses how the social context surrounding Swedish folk music creates value in the correlation between people and music.

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Chmayssani, Toufic. "Modulation sur les canaux vocodés." Phd thesis, Université Paris-Est, 2010. http://tel.archives-ouvertes.fr/tel-00587629.

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Les canaux vocodés sont les canaux de communications dédiés à la voix et dans lesquels le signal traverse divers équipements destinés au transport de la voix tels que des codeurs de parole, des détecteurs d'activité vocale (VAD), des systèmes de transmission discontinue (DTX). Il peut s'agir de systèmes de communications téléphoniques filaires ou mobiles (réseaux cellulaires 2G/3G, satellites INMARSAT...) ou de voix sur IP. Les codeurs de parole dans les normes récentes pour les réseaux de téléphonie mobiles ou de voix sur IP font appel à des algorithmes de compression dérivés de la technique CELP (Code Excited Linear Prediction) qui permettent d'atteindre des débits de l'ordre de la dizaine de Kb/s bien inférieurs aux codeurs des réseaux téléphoniques filaires (typiquement 64 ou 32 Kb/s). Ces codeurs tirent leur efficacité de l'utilisation de caractéristiques spécifiques aux signaux de parole et à l'audition humaine. Aussi les signaux autres que la parole sont-ils généralement fortement distordus par ces codeurs. La transmission de données sur les canaux vocodés peut être intéressante pour des raisons liées à la grande disponibilité des canaux dédiés à la voix et pour des raisons de discrétion de la communication (sécurité). Mais le signal modulé transmis sur ces canaux vocodés est soumis aux dégradations causées par les codeurs de parole, ce qui impose des contraintes sur le type de modulation utilisé. Cette thèse a porté sur la conception et l'évaluation de modulations permettant la transmission de données sur les canaux vocodés. Deux approches de modulations ont été proposées pour des applications correspondant à des débits de transmission possibles assez différents. La principale application visée par la thèse concerne la transmission de parole chiffrée, transmission pour laquelle le signal de parole est numérisé, comprimé à bas débit par un codeur de parole puis sécurisé par un algorithme de cryptage. Pour cette application, nous nous sommes focalisés sur les réseaux de communications utilisant des codeurs CELP de débits supérieurs à la dizaine de Kb/s typiquement les canaux de communication mobiles de deuxième ou troisième génération. La première approche de modulation proposée concerne cette application. Elle consiste à utiliser des modulations numériques après optimisation de leurs paramètres de façon à prendre en compte les contraintes imposées par le canal et à permettre des débits et des performances en probabilité d'erreur compatibles avec la transmission de parole chiffrée (typiquement un débit supérieur à 1200 b/s avec un BER de l'ordre de 10-3). Nous avons montré que la modulation QPSK optimisée permet d'atteindre ces performances. Un système de synchronisation est aussi étudié et adapté aux besoins et aux contraintes du canal vocodé. Les performances atteintes par la modulation QPSK avec le système de synchronisation proposé, ainsi que la qualité de la parole sécurisée transmise ont été évalués par simulation et validés expérimentalement sur un canal GSM réel grâce à un banc de test développé dans la thèse.La deuxième approche de modulation a privilégié la robustesse du signal modulé lors de la transmission à travers un codeur de parole quelconque, même un codeur à bas débit tels que les codeurs MELP à 2400 ou 1200 b/s. Dans ce but, nous avons proposé une modulation effectuée par concaténation de segments de parole naturelle associée à une technique de démodulation qui segmente le signal reçu et identifie les segments de parole par programmation dynamique avec taux de reconnaissance élevé. Cette modulation a été évaluée par simulation sur différents codeurs de parole. Elle a aussi été testée sur des canaux GSM réels. Les résultats obtenus montrent une probabilité d'erreur très faible quelque soit le canal vocodé et le débit des codeurs de parole utilisés mais pour des débits possibles relativement faibles. Les applications envisageables sont restreintes à des débits typiquement inférieurs à 200 b/s.Enfin nous nous sommes intéressés aux détecteurs d'activité vocale dont l'effet peut-être très dommageable pour les signaux de données. Nous avons proposé une méthode permettant de contrer les VAD utilisés dans les réseaux GSM. Son principe consiste à rompre la stationnarité du spectre du signal modulé, stationnarité sur laquelle s'appuie le VAD pour décider que le signal n'est pas de la parole

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Talevi, Luca. "Sviluppo e test di un sistema BCI SSVEP-based." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11636/.

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Una Brain Computer Interface (BCI) è un dispositivo che permette la misura e l’utilizzo di segnali cerebrali al fine di comandare software e/o periferiche di vario tipo, da semplici videogiochi a complesse protesi robotizzate. Tra i segnali attualmente più utilizzati vi sono i Potenziali Evocati Visivi Steady State (SSVEP), variazioni ritmiche di potenziale elettrico registrabili sulla corteccia visiva primaria con un elettroencefalogramma (EEG) non invasivo; essi sono evocabili attraverso una stimolazione luminosa periodica, e sono caratterizzati da una frequenza di oscillazione pari a quella di stimolazione. Avendo un rapporto segnale rumore (SNR) particolarmente favorevole ed una caratteristica facilmente studiabile, gli SSVEP sono alla base delle più veloci ed immediate BCI attualmente disponibili. All’utente vengono proposte una serie di scelte ciascuna associata ad una stimolazione visiva a diversa frequenza, fra le quali la selezionata si ripresenterà nelle caratteristiche del suo tracciato EEG estratto in tempo reale. L’obiettivo della tesi svolta è stato realizzare un sistema integrato, sviluppato in LabView che implementasse il paradigma BCI SSVEP-based appena descritto, consentendo di: 1. Configurare la generazione di due stimoli luminosi attraverso l’utilizzo di LED esterni; 2. Sincronizzare l’acquisizione del segnale EEG con tale stimolazione; 3. Estrarre features (attributi caratteristici di ciascuna classe) dal suddetto segnale ed utilizzarle per addestrare un classificatore SVM; 4. Utilizzare il classificatore per realizzare un’interfaccia BCI realtime con feedback per l’utente. Il sistema è stato progettato con alcune delle tecniche più avanzate per l’elaborazione spaziale e temporale del segnale ed il suo funzionamento è stato testato su 4 soggetti sani e comparato alle più moderne BCI SSVEP-based confrontabili rinvenute in letteratura.

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Thorell, Hampus. "Voice Activity Detection in the Tiger Platform." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6586.

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Sectra Communications AB has developed a terminal for encrypted communication called the Tiger platform. During voice communication delays have sometimes been experienced resulting in conversational complications.

A solution to this problem, as was proposed by Sectra, would be to introduce voice activity detection, which means a separation of speech parts and non-speech parts of the input signal, to the Tiger platform. By only transferring the speech parts to the receiver, the bandwidth needed should be dramatically decreased. A lower bandwidth needed implies that the delays slowly should disappear. The problem is then to come up with a method that manages to distinguish the speech parts from the input signal. Fortunately a lot of theory on the subject has been done and numerous voice activity methods exist today.

In this thesis the theory of voice activity detection has been studied. A review of voice activity detectors that exist on the market today followed by an evaluation of some of these was performed in order to select a suitable candidate for the Tiger platform. This evaluation would later become the foundation for the selection of a voice activity detector for implementation.

Finally, the implementation of the chosen voice activity detector, including a comfort noise generator, was done on the platform. This implementation was based on the special requirements of the platform. Tests of the implementation in office environments show that possible delays are steadily being reduced during periods of speech inactivity, while the active speech quality is preserved.

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Poirion, Olivier. "Discrimination analytique des génomes bactériens." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0033/document.

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Le génome bactérien est classiquement pensé comme constitué de “chromosomes”, éléments génomiques essentiels pour l’organisme, stables et à évolution lente, et de “plasmides”, éléments génomiques accessoires, mobiles et à évolution rapide. La distinction entre plasmides et chromosomes a récemment été mise en défaut avec la découverte dans certaines lignées bactériennes d’éléments génomiques intermédiaires, possédant à la fois des caractéristiques de chromosomes et de plasmides. Désignés par le terme de “chromosomes secondaires”, “mégaplasmides” ou “chromid”, ces éléments sont dispersés parmi les lignées bactériennes et sont couramment décrits comme des plasmides adaptés et modifiés. Cependant, leur véritable nature et les mécanismes permettant leur intégration dans le génome stable reste à caractériser. En utilisant les protéines liées aux Systèmes de Transmission de l’Information Génétique (STIG) comme variables descriptives des éléments génomiques bactériens (ou réplicons), une étude globale de génomique comparative a été conduite sur l’ensemble des génomes bactériens disponibles. A travers l’analyse de l’information contenue dans ce jeu de données par différentes approches analytiques, il apparait que les STIG constituent des marqueurs pertinents de l’état d’intégration des réplicons dans le génome stable, ainsi que de leur origine évolutive, et que les Réplicons Extra-Chromosomiques Essentiels (RECE) témoignent de la diversité des mécanismes génétiques et des processus évolutifs permettant l’intégration de réplicons dans le génome stable, attestant ainsi de la continuité du matériel génomique
The genome of bacteria is classically separated into essential, stable and slow evolving replicons (chromosomes) and accessory, mobile and rapidly evolving replicons (plasmids). This paradigm is being questioned since the discovery of extra-chromosomal essential replicons (ECERs), be they called ”megaplasmids”, ”secondary chromosomes” or ”chromids”, which possess both chromosomal and plasmidic features. These ECERs are found in diverse lineages across the bacterial phylogeny and are generally believed to be modified plasmids. However, their true nature and the mechanisms permitting their integration within the sable genome are yet to be formally determined. The relationships between replicons, with reference to their genetic information inheritance systems (GIIS), were explored under the assumption that the inheritance of ECERs is integrated to the cell cycle and highly constrained in contrast to that of standard plasmids. A global comparative genomics analysis including all available of complete bacterial genome sequences, was performed using GIIS functional homologues as parameters and applying several analytical procedures. GIIS proved appropriate in characterizing the level of integration within the stable genome, as well as the origins, of the replicons. The study of ECERs thus provides clues to the genetic mechanisms and evolutionary processes involved in the replicon stabilization into the essential genome and the continuity of the genomic material

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Mustafa, Abdul K. "Signal conditioning for high efficiency : wireless transmission." Thesis, 2010. https://vuir.vu.edu.au/24556/.

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Fourth generation (4G) mobile communication systems will need wider band-width channels and improved spectrum efficiency to achieve the specified LTE-advanced 100Mbps (mobile) and 1Gbps (fixed) wireless transmission target rate. The next generation of wireless basestations will also need to be powered from renewable sources, particularly in developing countries. A new generation of components, circuits, algorithms and transmission structures will therefore be required to meet the wider bandwidth and the lower energy requirements. This thesis addresses the transmitter chain, which dominates the basestation power budget. In particular we consider pre-conditioning algorithms for a new generation of high efficiency radio frequency power amplifiers (RFPA).

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Su, Chun-Yi, and 蘇峻億. "HHT-based Clinical Alcoholic EEG Signals Time Frequency Analysis with Transmission Error." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/17191909187638519271.

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碩士
國立臺灣海洋大學
電機工程學系
98
In this thesis, we discuss the application of a Hilbert-Huang transformation(HHT) based on time-frequency scheme to the analysis of the Fp2 electroencephalogram(EEG) signals of clinical alconholic and normal observers. We have previously discussed the time-frequency characteristics of clinical Fp1 EEG signals recorded from normal and alcoholic observers watching one picture and two different pictures[1,2]. In this thesis, we describe how we have extended this research to analyze clinical Fp2 EEG signals recorded from normal and alcoholic observers watching one picture. The HHT is one of the major time-frequency analysis schemes and is suitable for the analysis of local time signals. We also identify the intrinsic mode functions, instantaneous frequencies, Hilbert marginal frequencies, and Hilbert energy spectra of EEG signals recorded from the alcoholic and normal observers. When the transmission bit error rate is 10-4, the performance of the clinical alcoholic EEG signals based on HHT time-frequency characteristics is not affected.

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26

Meyers, Aaron J. "Coding and modulation for pixelated optical transmission." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=81063&T=F.

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Wong, Joshua K. H. "Spatial filtering in anisotropic transmission-line metamaterials." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=95051&T=F.

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Grbic, Anthony. "Super-resolving negative-refractive-index transmission-line lenses /." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442442&T=F.

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Thesis (Ph. D.)--University of Toronto, 2006.
Source: Dissertation Abstracts International, Volume: 67-06, Section: B, page: 3325. Advisor: George V. Eleftheriades. Includes bibliographical references.

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Teng, Ping-Wen, and 鄧品文. "Design and Verification of Wearable Wireless Wi-Fi Transmission 64 channels High Resolution EEG Acquisition System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/xb23ry.

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碩士
國立交通大學
電控工程研究所
103
The brain-computer interface (BCI) technique is a method of communication between the brain and the external world. This technology had been extensively studied. However, the BCI instruments with high measured signal quality are always heavy and huge. Thus, recording EEG tends to be an inconvenience task. In recent years, a high level of system chip (System on Chip, SOC) integration and development of sensors commonly used in wireless portable devices in BCI research, but there are still not enough. With the development of neuroscience, EEG signal analysis needs more accurate data. Due to the limited bandwidth of Bluetooth wireless transmission technology, the use of more than 16 channel EEG measurement system need to reduce the sampling rate, otherwise it will cause data loss. Therefore, this proposed study aimed at developing a multi-channel, high-resolution (24 bits), high sampling rate, Wi-Fi transmission EEG brain-computer interface devices. Hope this system can make contributions in neuroscience research. The EEG acquisition system proposed in this thesis is based on Cortex-M4 microcontroller with Wi-Fi subsystem. Committing to the multi-channel design, and also enhance the signal quality. This system can be used with wet sensor, Ag/AgCl electrode or dry sensors. The user-interface (Labview) receives EEG data via Wi-Fi transmission and also saves raw data for off-line analysis. On the other hand, RS-232 would be used for sending event’s tag in some cognitive experiments. The system had been validated by SSVEP, ERP experiments, etc. Results of these experiments demonstrate that this system can be used well for EEG measurements and is feasible for practical applications.

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葉陳欽. "HHT-based Clinical FZ EEG Signals Recorded From Alcoholic Observers Watching One Picture With Transmission Error." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/98293732727230405298.

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Wan, Yudi. "Role of versican in the regulation of glutamatergic synaptic transmission." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370402&T=F.

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Kang, Eunji Ellen. "Effects of mitochondrial dysfunction on synaptic transmission in rat hippocampal slices." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370461&T=F.

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Sheikh, Omar M. "Autonomic management of transmission resources via reinforcement learning for cognitive radio." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=452943&T=F.

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Siddiqui, Omar. "Resonance-cone propagation in continuous transmission-line grids and microwave applications." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=479010&T=F.

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王浩民. "HHT-based Time-frequency Features Of The FP2 EEG Signals With Transmission Error For Clinical Alcoholic Observers Watching." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/62534454793785751439.

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Majchrowski, Barbara K. "A risk management approach to ensuring reliable transmissions of co-located wireless systems in the healthcare environment." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=94871&T=F.

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Rodriguez, Suarez Emma. "Transmission of traditional musics and music teaching and learning in the Canary Islandsn : perspective." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370832&T=F.

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Klempan, Timothy Arthur. "Transmission analysis of presynaptic and neurodevelopmental candidate gene variants in schizophrenia and bipolar affective disorder." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=94769&T=F.

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Campbell, Christina Shelly. "Horizontal transmission of Nosema fumiferanae (Microsporidia: Nosematidae) in the spruce budworm (Choristoneura sp., Lepidoptera: Tortricidae)." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=788728&T=F.

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Graff, Eric. "The transmission and reception of "The Cloud of Unknowing" and the works of the "Cloud"-corpus." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442522&T=F.

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Fan, Cary. "Characterization of a gradient sensitive transmission chamber as an online monitor for intensity modulated radiation therapy." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=788985&T=F.

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Nock, Charles Andrew. "Crown thinning in canopy trees of two temperate deciduous species: Implications for light transmission in tolerant hardwood forests." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=450448&T=F.

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Pathan, Nazia Islam. "Ultrastructural examination of Arabidopsis thaliana wild type and ahp2 mutant meiotic nuclei using serial sections for transmission electron microscopy." 2009. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=958015&T=F.

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Hong, Claire. "Mapping the distribution of cell surface molecules by chromophore localization in the transmission electron microscope via low electron energy loss imaging." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=95157&T=F.

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Valentino, Caterina Lucia. "The role of middle managers in the transmission and integration of organizational culture : a case study in a merged health care organization." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=80152&T=F.

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Dissertations / Theses on the topic 'EER transmissions'

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