A rapid growth of installed wind power capacity is expectedin the next few years. However, the siting of wind turbines ona large scale raises concerns about their environmental impact,notably with respect to noise. To this end, variable speed windturbines offer a promising solution for applications in denselypopulated areas like the European countries, as this designwould enable an efficient utilisation of the masking effect dueto ambient noise. In rural and recreational areas where windturbines are sited, the ambient noise originates from theaction of wind on the vegetation and about the listener's ear(pseudo-noise). It shows a wind speed dependence similar tothat of the noise from a variable speed wind turbine and cantherefore mask the latter for a wide range of conditions.However, a problem inherent to the design of these machines istheir proclivity to pure tone generation, because of theenhanced difficulty of avoiding structural resonances in themechanical parts. Pure tones are deemed highly annoying and areseverely regulated by most noise policies. In relation to thisproblem, the vibration transmission of structure-borne sound tothe tower of the turbine is investigated, in particular whenthe tower is stiffened at its upper end. Furthermore, sincenoise annoyance due to wind turbine is mostly a masking issue,the wind-related sources of ambient noise are studied and theirmasking potentials assessed. With this aim, prediction modelsfor wind-induced vegetation noise and pseudo-noise have beendeveloped. Finally, closely related to the effect of masking,is the difficulty, regularly encountered by local authoritiesand wind farm developers, to measure noise immission from windturbines. A new measurement technique has thus been developedin the course of this work. Through improving thesignal-to-noise ratio between wind turbine noise and ambientnoise, the new technique yields more accurate measurementresults. Keywords: Masking, vibration transmission, diffraction,ambient noise, pseudo-noise, cylindrical shell, perturbationmethods, structural mobility, acoustic outdoor measurement. / QC 20100616

Thesis (Ph. D.)--University of California, San Diego, 2000. / Vita. Includes bibliographical references (leaves 154-163).

Thesis (Au.D.)--James Madison University, 2010. / Includes bibliographical references.

Made available in DSpace on 2014-12-17T15:37:20Z (GMT). No. of bitstreams: 1 FabianaBG.pdf: 675464 bytes, checksum: 93b2c2f3e1dc89bbd01f6cd8013ef59a (MD5) Previous issue date: 2006-06-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Otherwise, light can act directly on expressed rhythm, without act on the biological oscillators, promoting the masking. Thus, photic stimuli can synchronize the circadian activity rhythm (CAR) by two distinct mechanisms, acting isolated or at a combined way. Among the elements that can influence photic synchronization, the duration and time of photic exposure is pointed out. If in the natural environment the marmoset can choose places of different intensity illumination and is synchronized to light-dark cycle (LD), how the photic synchronization mechanism can be evaluated in laboratory by light self-selection? With objective to response this question, four adult male marmosets were studied at two conditions: with and without sleeping box. The animals were submitted to a LD cycle (12:12/ 350:2 lx) and constant light (LL: 350 lx) conditions in individual cages with an opaque sleeping box, that permitted the light self-selection. At the room, the temperature was 25.6 ?C (? 0.3 ?C) and humidity was 78.7 (? 5%). The motor activity was recorded at 5 min bins by infrared movement sensors installed at the top of the cages. The motor activity profile was distinct at the two conditions: without the sleeping box protection against light, the activity frequency was higher at CT 11-12 (ANOVA; F(3.23) = 62.27; p < 0.01). Also, the duration of the active phase (&#945;) was prolonged of about 1 h (t test, p < 0.05) and the animals showed a significant delay on the activity onset and offset (t test, p < 0.05) and at the acrophase (confidence intervals of 5%) of CAR. In LL, the light continuous exposure prolonged the active phase and influenced the endogenous expression of the circadian activity rhythm period. From the result analysis, it is concluded that the light self-selection can modify several parameters of CAR in marmosets, allowing the study of the synchronization mechanism using the burrow model. Thus, without sleeping box there was a phase delay between the CAR and LD (entrainment) and an increase of activity near lights off (positive masking). Furthermore, in LL, the light continuous exposure modifies &#945; and the endogenous expression of CAR. It is suggested that the light self-selection might be take into account at investigations that evaluate the biological rhythmicity in marmosets / Os sag?is, Callithrix jacchus, s?o primatas estritamente diurnos. A ritmicidade da atividade motora ? gerada pelo sistema de temporiza??o circadiano e modulada por fatores ambientais, principalmente pelos est?mulos f?ticos que comp?em o ciclo claro e escuro. Os est?mulos f?ticos podem ajustar os osciladores biol?gicos promovendo mudan?as no padr?o r?tmico da atividade, mecanismo denominado de arrastamento. Em contrapartida, a a??o direta sobre o ritmo expresso, sem atuar nos osciladores biol?gicos, promove o mascaramento. Dessa forma, os est?mulos f?ticos s?o capazes de induzir dois mecanismos distintos que, de forma isolada ou conjunta, podem levar ? sincroniza??o do ritmo circadiano de atividade motora (RCA). Dentre os elementos que influenciam a sincroniza??o, destacam-se a dura??o e os momentos de exposi??o ? luz. Se no ambiente natural, os sag?is podem optar por locais de diferentes intensidades luminosas e est?o sincronizados ao ciclo claro-escuro (CE), como os mecanismos da sincroniza??o f?tica podem ser avaliados em laborat?rio, atrav?s da auto-sele??o ? luz? Com o objetivo de responder a essa quest?o, foram estudados quatro sag?is machos adultos em duas condi??es: com e sem a caixa-ninho. Os animais foram submetidos ao ciclo CE (12:12/ 350:2 lux) e ao claro constante (CC: 350 lux) em gaiolas individuais contendo em seu interior uma caixa-ninho opaca, que permitia a auto-sele??o ? luz. Na sala, a temperatura foi de 25,6?C (? 0,3?C) e a umidade de 78,7 (? 5%). O registro da atividade motora foi realizado em intervalos de 5 min por sensores de movimento por infravermelho instalados sobre as gaiolas. O perfil da atividade motora foi distinto nas duas condi??es: sem a prote??o da caixa ninho contra a luz, a freq??ncia de atividade foi maior em CT 11-12 (ANOVA; F(3,23) = 62,27; p < 0,01). Sem caixa-ninho, a dura??o da fase ativa (&#945;) foi prolongada em cerca de 1 h (teste t, p < 0,05) e os animais apresentaram retardos significativos para o in?cio e t?rmino da atividade (teste t, p < 0,05) e para a acrofase (intervalos de confian?a a 5%) do RCA. Em CC, a exposi??o for?ada ? luz prolongou a fase ativa e modificou a express?o end?gena do per?odo do ritmo circadiano de atividade motora. A partir da an?lise dos resultados, conclu?mos que a auto-sele??o ? luz ? capaz de modificar diversos par?metros do ritmo circadiano de atividade motora em sag?is, permitindo o estudo dos mecanismos que mediam a sincroniza??o atrav?s do modelo de toca. Pois, na aus?ncia da caixa-ninho houve um atraso de fase entre o RCA e o CE (arrastamento) e um aumento da atividade motora no final da fase de claro (mascaramento positivo). Al?m disso, em CC, a exposi??o for?ada ? luz modificou o &#945; e a express?o end?gena do RCA. Portanto, sugere-se que a autosele??o ? luz deva ser considerada em estudos que avaliam a ritmicidade biol?gica em sag?is

Estudos sobre a orientação da atenção que utilizam o procedimento de Posner têm demonstrado dois efeitos: uma facilitação inicial no processamento do estímulo que aparece no lugar para onde dirigiu-se a atenção e subsequentemente um prejuízo no processamento deste estímulo, neste local. Em um trabalho anterior não evidenciamos o efeito facilitador da orientação da atenção em uma tarefa de tempo de reação simples. Levantamos algumas hipóteses para explicar este efeito oposto. Para testarmos tais hipóteses realizamos 6 experimentos. Nos dois primeiros, examinamos em que medida a presença de tentativas de pegada influenciava a expressão do efeito negativo do estímulo precedente. No terceiro examinamos a possibilidade do estímulo precedente ser capaz de reduzir a responsividade. No quarto equalizamos a intensidade efetiva do estímulo alvo nas duas posições em que ele podia ser apresentado (mesma e oposta). No quinto e no sexto avaliamos a evolução temporal do efeito negativo do estímulo precedente, na tentativa de determinar até que ponto ela teria alguma relação com a evolução temporal esperada para um mascaramento anterógrado. O sexto experimento poderia adicionalmente fornecer alguma pista de uma contribuição de uma inibição de retorno, neste caso precoce, para o efeito negativo encontrado. Em todos esses casos a influência atencional do estímulo precedente presumivelmente continuaria a ocorrer, mas seria suplantada pela influência contrária coexistente. Em conjunto, nossos resultados sugerem que o efeito negativo do estímulo precedente em uma tarefa de tempo de reação simples, se deve a uma interferência com o processamento do estímulo alvo, caracterizando uma inibição de natureza sensorial. / Studies about attention orienting that use Posner?s procedure have demonstrated two effects: an initial facilitation of responsivit when the target stimulus appears in the same location as the prime stimulus and a subsequent inhibition of this responsvity. In a previous work we could not find the early facilitatory effect of attention orienting in a simple reaction time task. The hypotheses that we raised to explain this unexpected finding were tested in six experiments. In the first two ones, we examined whether the presence of catch trials influenced the expression of the negative effect of the prime stimulus. In the third experiment we examined the possibility that the prime stimulus reduced responsivity. In the fourth experiment we equalized the intensity of the target stimulus in the two locations where it could be presented (same and opposite). In the fifth and in sixth experiments we evaluated the time course of the negative effect of the prime stimulus, as an attempt to verify whether it would be compatible with a forward masking process. The sixth experiment could additionally give some clue about a contribution of inhibition of return, in this case precocious, to the found negative effect. In all these cases the attentional influence of the prime stimulus would presumably continue to occur, but would be supplanted by the contrary negative of this stimulus influence. Overall, our results suggest that the negative effect of the prime stimulus in a simple reaction time task is due to an interference with the processing of the target stimulus, characterizing a kind of sensory inhibition.

Image and video quality evaluation is very important. In applications involving signal transmission, the Reduced- or No-Reference quality metrics are generally more practical than the Full-Reference metrics. Digital watermarking based quality evaluation emerges as a potential Reduced- or No-Reference quality metric, which estimates signal quality by assessing the degradation of the embedded watermark. Since the watermark contains a small amount of information compared to the cover signal, performing accurate signal quality evaluation is a challenging task. Meanwhile, the watermarking process causes signal quality loss. To address these problems, in this thesis, a framework for image and video quality evaluation is proposed based on semi-fragile and adaptive watermarking. In this framework, adaptive watermark embedding strength is assigned by examining the signal quality degradation characteristics. The "Ideal Mapping Curve" is experimentally generated to relate watermark degradation to signal degradation so that the watermark degradation can be used to estimate the quality of distorted signals. With the proposed framework, a quantization based scheme is first implemented in DWT domain. In this scheme, the adaptive watermark embedding strengths are optimized by iteratively testing the image degradation characteristics under JPEG compression. This iterative process provides high accuracy for quality evaluation. However, it results in relatively high computational complexity. As an improvement, a tree structure based scheme is proposed to assign adaptive watermark embedding strengths by pre-estimating the signal degradation characteristics, which greatly improves the computational efficiency. The SPIHT tree structure and HVS masking are used to guide the watermark embedding, which greatly reduces the signal quality loss caused by watermark embedding. Experimental results show that the tree structure based scheme can evaluate image and video quality with high accuracy in terms of PSNR, wPSNR, JND, SSIM and VIF under JPEG compression, JPEG2000 compression, Gaussian low-pass filtering, Gaussian noise distortion, H.264 compression and packet loss related distortion.

Ce travail de thèse porte sur l’étude de la croissance de nitrure d’éléments V sur des substrats de silicium (Si) (111) micro et nano-structuré. Son but est de simplifier l’hétéroépitaxie de GaN sur Si tout en gardant une qualité de matériau à l’état de l’art. L’originalité de ce travail repose sur la combinaison avantageuse de deux techniques de croissance : NH3-EJM et EPVOM. Nous avons d’abord évalué l’intérêt du silicium poreux (SiP) pour confiner les fissures et l’utiliser comme couche compliante. Malgré les changements structuraux s’opérant dans le SiP lorsqu’il est porté aux hautes températures nécessaires pour la croissance épitaxiale, nous avons pu démontrer la croissance de GaN de bonne qualité en ajoutant une couche de Si épitaxiée avant la croissance des nitrures d’éléments V. Puis, nous avons étudié la croissance de GaN dans des ouvertures réalisées dans un masque diélectrique déposé sur le substrat de Si. Cette approche a permis d’obtenir des motifs de GaN non fissurés et de bonne qualité cristalline en utilisant des conditions de croissance optimisées. L’analyse des contraintes sur les motifs de GaN indique une distribution en U où le maximum de la contrainte en tension est mesuré au centre des motifs ; cette contrainte se relaxe graduellement vers les bords libres des motifs. Enfin, une comparaison avec la croissance sur des mesas de Si gravé est proposée. Nous montrons que la croissance dans des ouvertures permet à la fois d’obtenir une couche de GaN uniformément épitaxiée sur les motifs ainsi que d’obtenir une plus faible courbure des substrats après croissance. Enfin, des LEDs ont pu être fabriquées à partir de GaN épitaxié sur substrat masqué. / This work deals with the growth of III-Nitrides on micro and nano-patterned silicon (111) substrates. The main goal is to simplify the heteroepitaxy of GaN on Si while keeping state of the art III-nitride materials. The originality of this work is to combine the advantages of both NH3-MBE and MOCVD growth techniques. We firstly evaluated the interest of porous silicon to confine cracks and to behave as a compliant substrate. Despite the issues regarding the structural changes of the porous silicon with the high temperatures necessary for the epitaxial growth of GaN, we demonstrated the growth of high quality GaN layers by growing a silicon layer of few tens of nanometers prior to III-nitride layers. Then, we studied the windowed growth of GaN on silicon substrates masked with dielectric films. We found that this approach can produce high quality crack free GaN (2µm thick) patterns with size up to 500x500 µm² with a dislocation density of few 108cm-2. Furthermore, crack statistics reveal that a large amount of crack free patterns can be obtained using optimized conditions. Stress analyses of GaN patterns demonstrate a “U-shape” stress distribution where the maximum tensile stress is found in the middle of the patterns and gradually decreases towards the pattern edges. Finally, a comparison with mesa patterned silicon substrates is proposed with identical grown structures. We found that windowed growth is more advantageous regarding growth uniformity and substrate bowing. As a result of this work, LEDs have been fabricated using GaN grown on masked substrates.

Chocholáčová, D.: Mask - Face - Facial expression. Theme utilization in pedagogical practice. /Diploma thesis/ Prague 2014 - Charles University, Faculty of Education, department of art education,83 p. Diploma thesis is oriented as a theoretical study and research of mask in prezent form with context of history. In this work mask is understanded as a communication between whole world and one person, when the individuality of person meets uniformity of mass. It deals with phenomenom of masking as a everyday manifestation human being identify with social group with specific culture tradition. Mask contemplates between ritual and fun, by probe of traditions, ceremonials, rituals and carnivals, but also probe of contemporary theatre or art . Diploma thesis also thinks about present position of ritual. Goal of the work is specify everyday human being, his mask, face, facial expression, at the modern world. Pedagogical utilization offers implementation theme to space of nursery school and grammar school offer of topics, mostly realized and reflected. Part of work is together finding theme at preparation and realization gallery education for two exhibitions in Rudolfinum Gallery.

Denna studien är en litteraturöversikt, det vill säga en överblick av befintlig forskning. Flickor/kvinnor med autismspektrumtillstånd är ett område som är relativt outforskat, vilket innebär en rad olika konsekvenser för denna grupp. Syftet med denna uppsatsen är att beskriva forskningsläget avseende att som flicka/kvinna leva med autism och därmed kunna identifiera behov av vidare forskning. Detta kommer att undersökas genom att svara på följande två frågeställningar. (1) Hur ser forskningsläget ut avseende att som flicka/kvinna leva med ett autismspektrumtillstånd? (2) Vilka kunskapsluckor kan identifieras? Resultatet visar att gruppen är utsatta på flera olika plan vilket i sin tur ger olika effekter i deras liv. En diagnos kan både främja men även motverka gruppens livsmöjligheter. Den kan leda till en bättre självkännedom och känslor av tillhörighet men kan även leda till sorg och depression. För att kunna förstå målgruppens komplexa situation krävs det mer / This report is a literature review, i.e. a review of existing research. Girls/Women with autism spectrum disorder is a relatively unexplored area. This entails a variety of different consequences for this group. The aim of this study is to describe the research area regarding living with autism spectrum disorder as a girl/woman in order to identify the need for further research. This will be reviewed by answering the following questions. (1) What does the research area regarding living with autism spectrum disorder as a girl/woman look like? (2) Which gaps of knowledge can be identified? The review shows that the group is vulnerable in many different aspects which affects their lives in different ways. A diagnosis can both help but also counteract the life chances of this group. It can lead to better self-awareness and a sense of belonging but leads to grief and depression as well. This area requires more research that can better explain the vulnerability of this group to help better understand their complex situation.

<p>Humans are able to hear and detect small changes in sound across a wide dynamic range despite limited dynamic ranges of individual auditory nerve fibers. One mechanism that may adjust the dynamic range is the medial olivocochlear reflex (MOCR), a bilateral sound-activated system which decreases amplification of sound by the outer hair cells in the cochlea. Much of the previous physiological MOCR research has used long broadband noise elicitors. In behavioral measures of gain reduction, a fairly short elicitor has been found to be maximally effective for an on-frequency, tonal elicitor. However, the effect of the duration of broadband noise elicitors on behavioral tasks is unknown. Additionally, MOCR effects measured using otoacoustic emissions (OAEs), have not consistently shown a positive correlation with behavioral gain reduction tasks. This finding seems counterintuitive if both measurements share a common generation mechanism. The current study measured the effects of ipsilateral broadband noise elicitor duration on psychoacoustic gain reduction (Chapter 2) and transient-evoked OAEs (TEOAEs) (Chapter 3) estimated from a forward-masking paradigm. Changes in the TEOAE were measured in terms of magnitude and phase. When phase was accounted for in the TEOAEs, the time constants were approximately equal to the psychoacoustic time constants, and were relatively short (~80 ms). When only changes in TEOAE magnitude were measured, and phase was omitted, the average time constants were longer (~172-ms). Overall, the psychoacoustic and physiological data were consistent with the timecourse of gain reduction by the MOCR. However, when the magnitudes from these data were directly compared in a linear mixed-effects model (Chapter 4), no positive predictive relationship was found, and in some cases there was a significant negative association between the physiological and psychoacoustic measures of gain reduction as a function of elicitor duration. The multitude of factors involved in this relationship are discussed, as are the implications of dynamic range adjustment in everyday listening conditions (noisy backgrounds) in both normal and hearing impaired listeners (Chapter 5).</p>