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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 21 to 27 of 27 (0.024 seconds)| 21 |
Girdimosios informacijos kokybės triukšmingoje aplinkoje tyrimai / Research of audio information quality in noisy environmentVasiliauskas, Gediminas 14 January 2009 (has links)
Darbo apimtis 69 puslapiai, 14 lentelių, 26 paveikslai, panaudotas 31 literatūros šaltinis, 4 priedai. Darbo tikslas yra ištirti sistemos „žmogus-mašina-aplinka“ elementų informacinį patikimumą ir išsiaiškinti garsinių signalų sklidimo triukšminga aplinka trukdžius bei įvertinti garsinės informacijos tokioje aplinkoje, kokybę. Darbe nagrinėjamas sistemos „žmogus-mašina-aplinka“ informacinis patikimumas ir jo neatitiktys situacijai, sukeliančios nepaprastuosius įvykius. Literatūros apžvalgoje didelis dėmesys skiriamas girdimosios informacijos kokybės pokyčių analizei esant triukšmui, aptariama klausos apsaugos priemonių įtaka darbuotojo informaciniam komfortui. Teoriniuose tyrimuose daug dėmesio skiriama erdvinės girdos ir garso šaltinio lokalizacijos biologiniams aspektams, analizuojami garsinio signalo kokybinio vertinimo rodikliai. Tyrimų rezultatų analizė rodo jog didelę reikšmę informacijos sklidimui turi jos amplitudinė dažninė charakteristika, o žmogus gali iš aplinkos išskirti net tuos signalus, kurių kalbos interferencijos rodiklis (SIL) mažesnis už 5dBA. Taip pat nustatyta, jog informaciniai signalai informatyvūs, kai jų lygis vienoje iš 4 oktavinių juostų bent 5 dBA aukštesnis, o klausos apsaugos priemonių slopinimas ne didesnis kaip 20 dBA. Darbe gauti rezultatai gali būti panaudoti kaip priedas vertinant profesinę riziką darbo vietose. / Work consists of 69 pages, 14 data tables, 26 illustrations, 4 attachments, 31 literature sources is used The purpose of this work is to investigate informational reliability of the “man-machine-environment” system and find out the difficulties of audible information spread in noisy environment and also estimate the quality of this information. „Man-machine-environment“system informational reliability is being analyzed in literature review section. An extensive attention intended for audible information quality in noise, influence of using hearing protectors also discussed. Finally spatial hearing and sound localization biological aspects reviewed, qualitative indexes of audible signal analyzed. Research analysis showed that significant account for audible information propagation has its amplitude frequentative characteristic but man can dissociate even these audible signals, of which speech interference level (SIL) is poor, or less than 5 dBA. Also determined that informational signals are informative when their level is at least 5 dBA higher in one of four octave bands and when hearing protector suppression is less than 20 dBA. Results can be used as extra information for professional risk assessment.
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Paysage esthétique de l'installation sonore / The aesthetic landscape of sound installationOrtiz Ceron, Maria Carolina 10 April 2015 (has links)
On appelle installation sonore une forme d'art multimédia dans laquelle l'accent est mis en particulier sur l’aspect sonore, sans pour autant ignorer toutes les autres composantes qui constituent l’installation. Bien qu’elle soit une forme classée parmi les arts plastiques, l’installation sonore se rapporte plutôt à l’art sonore. En effet, l’art sonore se caractérise par la prééminence de l’usage du son comme moyen d’expression et comme préoccupation artistique (le grand nombre de manifestations, de blogs et de festivals d’art sonore en témoignent). Parmi les pratiques expérimentales ayant trait à l’art sonore, une nette préférence va à l’installation sonore et il semblerait qu’elle devienne une forme d’art en soi. On peut s’interroger sur la possibilité d’envisager ceci de cette manière. Dans cette thèse, il faut comprendre l’installation sonore comme une pratique artistique hétérogène, interdisciplinaire, expérimentale et hybride, pratique qu’on retrouve dans l’installation artistique en général. Cependant, on peut constater que des préoccupations reviennent souvent : la visualisation du son, la perception de l’espace à travers le sonore, l’écoute et sa relation avec la position et le déplacement du corps de l’auditeur. Afin de contribuer à une plus grande compréhension d’une culture sonore contemporaine qui est largement partagée, le propos de cette thèse est d’étudier les divers domaines auxquels l’installation sonore appartient et ceci à partir de plusieurs points de vue : historique, esthétique, culturel et médiatique. / Sound installation is an inter media-based art form that draws particular attention to the component of sound, although not at the expense of its visual underpinnings. Considering that it is a form of art, sound installation refers to sound art, an area that requires separate recognition and independence among existing art forms, due to the use of sound as a means of expression as well as the current artistic preoccupation with it (as reflected in the growing number of sound art demonstrations, blogs and festivals).Among the different experimental practices within sound art, sound installation is clearly favored, thus it would appear that it is becoming an art form in itself. Could it be seen in this way? In this thesis, Sound Installation is viewed as a current art form connected to “Art installation”, a field with its own characteristics: heterogeneous, multi-disciplinary, experimental and hybrid. However, as a singular art form, it is a source of insight, which emerges repeatedly and is amplified by the exploration of both sound and sound perception; for example, sound imaging, the perception of space through sound, listening and its relationship to the position of the listener’s body in space. The purpose of this thesis is to approach the field in which Sound Installation belongs from different perspectives such as history, aesthetics, culture and media. With the question of how to conceptualize sound components always in mind, we intend to contribute to the understanding of an ever –growing contemporary culture of sound.
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Resolution of lateral acoustic space assessed by electroencephalography and psychoacousticsBennemann, Jan, Freigang, Claudia, Schröger, Erich, Rübsamen, Rudolf, Richter, Nicole 01 August 2022 (has links)
The encoding of auditory spatial acuity (measured as the precision to distinguish between two spatially distinct stimuli) by neural circuits in both auditory cortices is a matter of ongoing research. Here, the event-related potential (ERP) mismatch negativity (MMN), a sensitive indicator of preattentive auditory change detection, was used to tap into the underlying mechanism of cortical representation of auditory spatial information. We characterized the MMN response affected by the degree of spatial deviance in lateral acoustic space using a passive oddball paradigm. Two stimulation conditions (SCs)—specifically focusing on the investigation of the mid- and far-lateral acoustic space—were considered: (1) 65° left standard position with deviant positions at 70, 75, and 80°; and (2) 95° left standard position with deviant positions at 90, 85, and 80°. Additionally, behavioral data on the minimum audible angle (MAA) were acquired for the respective standard positions (65, 95° left) to quantify spatial discrimination in separating distinct sound sources. The two measurements disclosed the linkage between the (preattentive) MMN response and the (attentive) behavioral threshold. At 65° spatial deviations as small as 5° reliably elicited MMNs. Thereby, the MMN amplitudes monotonously increased as a function of spatial deviation. At 95°, spatial deviations of 15° were necessary to elicit a valid MMN. The behavioral data, however, yielded no difference in mean MAA thresholds for position 65 and 95°. The different effects of laterality on MMN responses and MAA thresholds suggest a role of spatial selective attention mechanisms particularly relevant in active discrimination of neighboring sound sources, especially in the lateral acoustic space.
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Localisation de source en milieu réverbérant par Retournement TemporelRibay, Guillemette 13 December 2006 (has links) (PDF)
Cette thèse concerne l'étude du Retournement Temporel (RT) en milieu réverbérant, appliqué d'une part à la focalisation d'ondes acoustiques audibles longues de plusieurs secondes à caractère aléatoire dans une chambre réverbérante, et d'autre par à la localisation d'impacts à la surface de plaques minces réverbérantes. <br />Concernant cette première application, une focalisation spatiale des signaux est observée tant numériquement qu'expérimentalement. Il est montré à la fois théoriquement et expérimentalement que le contraste ne dépend que du nombre d'éléments du Miroir à Retournement Temporel. Enfin, la robustesse de la focalisation lorsque la réciprocité du milieu est brisée entre les deux étapes du RT est étudiée. <br />D'autre part, afin de localiser des impacts à la surface de plaques réverbérantes, une technique reposant sur la comparaison des signatures acoustiques par corrélation est développée. L'analogie avec le RT, ainsi qu'une étude de la nature des ondes excitées par un impact à la surface de plaques, permettent de comprendre les capacités de cette techniques en terme de résolution et contraste. L'interaction de l'onde majoritaire (onde de Lamb A0) avec les bords de la plaque est également étudiée. En outre, un code de simulation numérique de la propagation de ce mode par différences finies dans l'approximation faible produit fréquence par épaisseur est développé. Enfin, l'influence des variations de température sur la technique de localisation par corrélation est étudiée numériquement, théoriquement et expérimentalement, dans plusieurs matériaux. Un changement de température entraîne une simple dilatation des réponses impulsionnelles, et est aisément compensé.
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Acoustic noise emitted from overhead line conductorsLi, Qi January 2013 (has links)
The developments of new types of conductors and increase of voltage level have driven the need to carry out research on evaluating overhead line acoustic noise. The surface potential gradient of a conductor is a critical design parameter for planning overhead lines, as it determines the level of corona loss (CL), radio interference (RI), and audible noise (AN). The majority of existing models for surface gradient calculation are based on analytical methods which restrict their application in simulating complex surface geometries. This thesis proposes a novel method which utilizes both analytical and numerical procedures to predict the surface gradient. Stranding shape, proximity of tower, protrusions and bundle arrangements are considered within this model. One of UK National Grid's transmission line configurations has been selected as an example to compare the results for different methods. The different stranding shapes are a key variable in determining dry surface fields. The dynamic behaviour of water droplets subject to AC electric fields is investigated by experiment and finite element modelling. The motion of a water droplet is considered on the surface of a metallic sphere. To understand the consequences of vibration, the FEA model is introduced to study the dynamics of a single droplet in terms of phase shift between vibration and exciting voltage. Moreover, the evolution of electric field within the whole cycle of vibration is investigated. The profile of the electric field and the characteristics of mechanical vibration are evaluated. Surprisingly the phase shift between these characteristics results in the maximum field occurring when the droplet is in a flattened profile rather than when it is ‘pointed’.Research work on audible noise emitted from overhead line conductors is reviewed, and a unique experimental set up employing a semi-anechoic chamber and corona cage is described. Acoustically, this facility isolates undesirable background noise and provides a free-field test space inside the anechoic chamber. Electrically, the corona cage simulates a 3 m section of 400 kV overhead line conductors by achieving the equivalent surface gradient. UV imaging, acoustic measurements and a partial discharge detection system are employed as instrumentation. The acoustic and electrical performance is demonstrated through a series of experiments. Results are discussed, and the mechanisms for acoustic noise are considered. A strategy for evaluating the noise emission level for overhead line conductors is developed. Comments are made on predicting acoustic noise from overhead lines. The technical achievements of this thesis are summarized in three aspects. First of all, an FEA model is developed to calculate the surface electric field for overhead line conductors and this has been demonstrated as an efficient tool for power utilities in computing surface electric field especially for dry condition. The second achievement is the droplet vibration study which describes the droplets' behaviour under rain conditions, such as the phase shift between the voltage and the vibration magnitude, the ejection phenomena and the electric field enhancement due to the shape change of droplets. The third contribution is the development of a standardized procedure in assessing noise emission level and the characteristics of noise emissions for various types of existing conductors in National Grid.
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Pre-Existing Film Music Re:sourced : Technical Aspects and Narratological Implications of Audible Diegetic Transitions in Joker and Other Films / Förflyttning av tidigare existerande filmmusik : Tekniska aspekter och narratologiska implikationer av hörbara diegetiska övergångar i Joker och andra filmerDanstål Skiöld, Martin January 2023 (has links)
This thesis concerns itself with a phenomenon found in film music that can be described as audible diegetic transitions. In short, an audible diegetic transition occurs when film music shifts from one implied musical placement to another by changing its presented sound quality. This occurs predominantly through the employment of music that is pre-existing in relation to the release of the film where the music is utilised. These audible diegetic transitions are categorised as aural displacements and transaural displacements which are both anchored in previous research concerning stable musical placements. In order to answer the research questions regarding technical aspects and narratological implications, the thesis is centred around a film music analysis. The demarcation of said analysis uses pre-existing songs from the film Joker (Philips, 2019) as its main focus. In order to provide a colourful and meaningful discussion the selected material also contains a variety of examples from other films. The analysis shows that the selected audible diegetic transitions can provide narratological implications both for a film as a whole and for a specific scene or sequence in any film. In Joker specifically, the audible diegetic transitions arguably contain the narratological implication of adding to the retrospective and unreliable narration, which is important for the story of the film. The thesis also argues that the technical aspects of the analysed audible diegetic transitions can be condensed into being either diegetic to commentary, or vice versa. Diegetic music is, in this context, defined as music that is implied as being heard in the acoustic space of the story-world, whereas commentary music is an umbrella term defined as music that is not implied being heard in the acoustic space of the story-world. The analysis shows that these transitions can transpire either instantly or gradually with the change of sound quality from being either narrow or wide. These technical aspects contribute in understanding the narratological implications of said audible diegetic transition by categorising them as either emotive or grounding. Both of these narratological implications can be concluded and described as swift enforcers of the relationship between the one consuming the film and the characters, or locations, of the film they are consuming. Audible diegetic transitions figuratively breach the fourth wall that is the screen.
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Green RelationshipImad, Fadel 01 May 2014 (has links)
Green Relationship is a design solution attempting to raise awareness toward the environment and reduce consumerism. Waste generation and pollution have become major concerns of many governments, municipalities, organizations and individuals around the world since they are affecting human wellbeing and the environment. As an MFA student with VCUQatar, I chose to use design to contribute in protecting the environment hoping to make a difference in life. The thesis includes a research and a design component. The research explores the recycling programs and facilities in Qatar, the governmental and private sector actions toward waste generation and collection, as well as precedent solutions applied around the world. Furthermore, it includes a survey on recycling to gather and analyze the community’s feed back in order to come up with a solution that aims to change people’s behavior toward waste generation and to promote green lifestyle. The design component defines the Green Relationship as the personal connection between the individual and the silent partner, “the environment.” It fulfills the basic survival needs, “food and water,” and the one and only independency need, “oxygen.” The elements of the Green Relationship are the projection of the generic relationships elements we know of through the theory of “Humimicing” that I introduce in my thesis. Humimicing is the design theory that mimics human innate attributes and behaviors to develop design concepts to be applied in different industries. Every element of the Green Relationship is visualized through a different design discipline similar to its nature. Therefore, interactive, product and critical designs are the mediums used to represent Green Communication, Care and Ethics respectively through public installation, experimentation and conceptual design definition. The thesis methodology, which is “Make it Personal,” concludes in creating the Green Relationship that aims to change the behavior of individuals and ultimately to reach out to the wider community. Under the maxim, “Green is not just a color; it is a Lifestyle,” the thesis promotes the use of design to inspire people, designers and manufacturers to consume less and generate less waste in order to save natural resources and the environment.
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