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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the 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.
1

"Parâmetros acústicos subjetivos: critérios para avaliação da qualidade acústica de salas de música" / Subjective Acoustical Parameters: Criteria for Evaluation of Acoustical Quality of Music Halls

Figueiredo, Fabio Leao 29 September 2005 (has links)
Os parâmetros acústicos subjetivos são critérios que definem a qualidade acústica de uma sala de música. A apreciação musical dentro da sala é afetada por diversas impressões acústicas que ocorrem ao mesmo tempo. Cada uma dessas impressões é associada a um parâmetro acústico de natureza subjetiva que está correlacionado a uma grandeza física mensurável, constituindo um conjunto de parâmetros acústicos objetivos que formam uma base científica para a análise acústica das salas de música. Neste trabalho desenvolvemos pesquisa de âmbito teórico e experimental envolvendo a análise dos parâmetros acústicos subjetivos mais relevantes para a avaliação da qualidade acústica de salas de escuta musical. Fizemos um levantamento abrangente do material já publicado sobre o assunto, o que nos orientou a respeito das medições acústicas pertinentes à referida análise e nos permitiu formalizar as devidas conclusões. Implementamos e aplicamos a tecnologia necessária para a obtenção dos parâmetros. Determinamos a metodologia experimental mais adequada e efetuamos medições em seis importantes salas de concerto, comparando os resultados. Fizemos uma análise crítica a respeito dos parâmetros acústicos obtidos e aprofundamos a compreensão sobre seus significados e suas utilidades. Por fim, fizemos uma análise subjetiva de júri correlacionando os parâmetros acústicos medidos às respectivas impressões acústicas sobre amostras musicais gravadas nas salas. / Acoustic parameters are the criteria that define the acoustic quality of a music hall. The musical audition inside a room is influenced by a group of acoustic impressions that occur at the same time. Each one of such impressions is associated with a particular subjective parameter that is correlated to a measurable physical value. These values are taken as a set of objective parameters that constitute a scientific basis for the acoustical analysis of a music hall. In this work we have conducted both a theoretical and an experimental investigation on the analysis of the most important acoustic parameters for the evaluation of the quality of a music hall. Also, we have done an extensive research on the related bibliography to support our measurement procedures and formal conclusions. We have implemented the necessary technology to obtain the acoustic parameters. We also have determined the most efficient experimental methodology to carry out acoustic measurements and we have applied this methodology to the measurement of six important concert halls. Then we have compared the data related to each hall and performed a critical analysis of this data, increasing our understanding on the meaning and the usefulness of the acoustic parameters. Finally, we have made a subjective jury analysis, correlating the measured acoustic parameters to the impressions about music samples recorded into those concert halls.
2

"Parâmetros acústicos subjetivos: critérios para avaliação da qualidade acústica de salas de música" / Subjective Acoustical Parameters: Criteria for Evaluation of Acoustical Quality of Music Halls

Fabio Leao Figueiredo 29 September 2005 (has links)
Os parâmetros acústicos subjetivos são critérios que definem a qualidade acústica de uma sala de música. A apreciação musical dentro da sala é afetada por diversas impressões acústicas que ocorrem ao mesmo tempo. Cada uma dessas impressões é associada a um parâmetro acústico de natureza subjetiva que está correlacionado a uma grandeza física mensurável, constituindo um conjunto de parâmetros acústicos objetivos que formam uma base científica para a análise acústica das salas de música. Neste trabalho desenvolvemos pesquisa de âmbito teórico e experimental envolvendo a análise dos parâmetros acústicos subjetivos mais relevantes para a avaliação da qualidade acústica de salas de escuta musical. Fizemos um levantamento abrangente do material já publicado sobre o assunto, o que nos orientou a respeito das medições acústicas pertinentes à referida análise e nos permitiu formalizar as devidas conclusões. Implementamos e aplicamos a tecnologia necessária para a obtenção dos parâmetros. Determinamos a metodologia experimental mais adequada e efetuamos medições em seis importantes salas de concerto, comparando os resultados. Fizemos uma análise crítica a respeito dos parâmetros acústicos obtidos e aprofundamos a compreensão sobre seus significados e suas utilidades. Por fim, fizemos uma análise subjetiva de júri correlacionando os parâmetros acústicos medidos às respectivas impressões acústicas sobre amostras musicais gravadas nas salas. / Acoustic parameters are the criteria that define the acoustic quality of a music hall. The musical audition inside a room is influenced by a group of acoustic impressions that occur at the same time. Each one of such impressions is associated with a particular subjective parameter that is correlated to a measurable physical value. These values are taken as a set of objective parameters that constitute a scientific basis for the acoustical analysis of a music hall. In this work we have conducted both a theoretical and an experimental investigation on the analysis of the most important acoustic parameters for the evaluation of the quality of a music hall. Also, we have done an extensive research on the related bibliography to support our measurement procedures and formal conclusions. We have implemented the necessary technology to obtain the acoustic parameters. We also have determined the most efficient experimental methodology to carry out acoustic measurements and we have applied this methodology to the measurement of six important concert halls. Then we have compared the data related to each hall and performed a critical analysis of this data, increasing our understanding on the meaning and the usefulness of the acoustic parameters. Finally, we have made a subjective jury analysis, correlating the measured acoustic parameters to the impressions about music samples recorded into those concert halls.
3

Predictions On Absorption And Scattering Characteristics Of Acoustic Scatterers Modified With Micro-perforated Panels

Odabas, Erinc 01 September 2012 (has links) (PDF)
In this study, the basic absorption and scattering characteristics of acoustic scatterers, specifically Schroeder Diffusers, are investigated. Schroeder Diffusers are one of the most widely used acoustic scatterers in which the scattering phenomenon is predictable due to the geometry of the diffuser, based on a particular mathematical sequence. It is shown that it is possible to increase the amount of absorption by modifying the diffuser structure by means of adding perforated panels into the wells or narrowing diffuser wells. In room acoustics applications, diffusers are conventionally mounted to a wall or ceiling assumed to be rigid enough such that sound wave cannot penetrate through. This thesis proposes a new modification on these diffusers where the diffuser is not backed by a rigid surface / it is hung over a space instead. To construct such a configuration, diffuser wells are terminated with micro-perforated panels (MPP). Inclusion of MPP introduces additional losses / hence, higher absorption can be achieved. However, the most significant absorption in this configuration is achieved below the first resonance frequency of the panel-air space system due to the existence of non-rigid backing. This thesis aims to model the absorption and scattering mechanisms enabled with the non-rigid backing by improving a previously introduced mathematical model.
4

Development of a fast method for the psychophysical estimation of nonlinear cochlear function using schroeder-phase masking.

Rahmat, Sarah Binti January 2015 (has links)
In many previous physiological and psychoacoustic studies, Schroeder-phase masking (using Schroeder harmonic complexes to mask other sounds) has proven useful in understanding different aspects of cochlear function, particularly the phase curvature of the cochlea and cochlear nonlinearity. The common method of measuring Schroeder-phase masking functions uses a very time consuming three-alternative forced choice (3AFC) process, which limits its research and clinical usefulness. This thesis describes a fast method for measuring Schroeder-phase masking functions that we developed to address this problem. By adapting the Békésy tracking technique, we demonstrate how the measurement time can be reliably shortened by almost 80% in comparison to the commonly-used method. Using the fast method, we have demonstrated that the difference in masking effectiveness produced by different phases of Schroeder maskers (known as the ‘phase effect’) is reduced in conditions where cochlear non-linearity is expected to be reduced (i.e. at low intensity levels and in sensorineural hearing loss subjects) – findings which are consistent with previous studies. The possible involvement of other mechanisms in producing the Schroeder phase effect (particularly the medial olivocochlear (MOC) reflex) is discussed. Given the shorter testing time and higher resolution data it can give, the fast method can be a useful tool in estimating cochlear phase curvature. The reduction in testing time in particular may significantly aid the investigation of different aspects of cochlear function which might have been limited by the long testing time given by the commonly-used method.
5

Specifikační jazyky a nástroje pro analýzu a verifikaci bezpečnostních protokolů / Specification Languages and Tools for Analysis and Verification of Security Protocols

Ptáček, Michal Unknown Date (has links)
This diploma thesis is focused on the analysis of security tools, which are commonly used for automatic verification of security protocols mainly. These security protocols are used for creation of private communication channells in insecured networks. Security will never be perfect, so finding of weaknesses in security protocols is always necessary and we need to improve these protocols. In this diploma thesis I have focused on looking for various verification tools on Internet. Subsequently, I have described each tool in this thesis, in way that each reader can easily find out, which tool is for him useful and which is not. I have summarized main benefits and drawbacks of each tool at the end of his description.
6

Les anciens de Weimar à Bonn. Itinéraires de 34 doyens et doyennes de la seconde démocratie parlementaire allemande / The “Weimarian” in Bonn : exploring the Political Trajectories of 34 Representatives from the Weimar Reichstag to the Bundestag in Bonn / Die Weimaraner in Bonn : lebensläufe 34 erfahrenen Parlamentarier der zweiten Deutschen parlamentarischen Demokratie

Bernier-Monod, Agathe 21 November 2017 (has links)
Cette thèse explore la continuité entre le Reichstag de Weimar et le Bundestag de Bonn à travers les itinéraires de 34 élus ayant siégé dans les deux chambres. L’élaboration du portrait socio-politique du groupe considéré aboutit au constat d’une diversité fondamentale, mais aussi à l’identification de milieux socio-moraux structurant la vie politique de l’Allemagne impériale. Ces acteurs vécurent différemment leur passage au Reichstag avant 1933, suivant leur parti, leur genre, la date et circonscription de leur élection ou les fonctions qu’ils exercèrent au parlement. La mise au pas du Reichstag et l’effondrement de la République marquèrent un tournant dans leur existence. La recherche des causes de l’échec weimarien les accompagna toute leur vie. Les personnalités étudiées réagirent différemment à la dictature nazie. Si leurs situations varient considérablement entre 1933 et 1945, ces années se résument globalement à une expérience de la perte. Les anciens du Reichstag furent les cibles privilégiées de persécutions visant à briser toute opposition au nazisme. L’expérience de l’oppression les mua en démocrates attentifs et favorisa leur retour en politique dès 1945. La plupart participèrent à la refondation institutionnelle de l’Allemagne de l’Ouest entre 1945 et 1949. Leurs retrouvailles avec le parlement à partir de 1949 furent difficiles dans la mesure où ils percevaient le Bundestag à travers le filtre de leur souvenir du Reichstag. Au Bundestag, ils mirent à profit leur connaissance du travail parlementaire, contribuant ainsi à stabiliser le nouvel État. Certains y perpétuèrent une culture politique forgée avant 1933 qui peut être qualifiée d’« esprit de Weimar ». / This PhD thesis studies the continuity between the Weimar Reichstag and the Bundestag in Bonn from the perspective of 34 representatives who were elected in both chambers. Constructing the socio-political portrait of this group reveals an essential diversity while at the same time leading to the identification of the socio-moral backgrounds that structured political life in imperial Germany. These men and women experienced their time in the Reichstag differently, depending on their party, gender, constituency, the period in question, and the place they occupied in parliament.The neutralisation of the Reichstag and the fall of the Republic marked a turning point in their lives. The question of why the Weimar Republic had failed would follow them for the rest of their lives. The members of this group reacted differently to the Nazi dictatorship. If their situations varied considerably between 1933 and 1945, the period was generally marked by the experience of loss. The former members of the Reichstag were the main targets of Nazi persecutions aimed at opponents of the regime. Living through oppression turned them into considerate democrats and encouraged their return to politics. Most took part in the institutional reconstruction of West Germany between 1945 and 1949. Their reunion with the parliament from 1949 onward was difficult, since they perceived the Bundestag through the prism of their past experience in the Reichstag. In the Bundestag, they built on their knowledge of parliamentary work, thereby contributing to stabilising the new state. Some of them perpetuated a political culture that had been shaped before 1933 and which can be described as “the Weimar spirit”.
7

Databáze specifikací bezpečnostních protokolů / Specifications Database of Security Protocols

Hadaš, Petr Unknown Date (has links)
This paper describes four tools for verification security protocols Athena, Casper, Isabelle and Murphi. Each tool is briefly characterized and implementation of protocol Needham Schroeder. One part of this paper is comparing of selected tools. The second part of this paper describes in detail a tool Athena and mentions examples of verified protocols. By each protocol is stated a specifications of communication, a detected attack and results of own verification. At the end compares this paper verification results with already publicated attacks.
8

Německá zahraniční politika vůči Rusku v období vlád G.Schroedera a A.Merkelové / German foreign policy towards Russia during the governments of G. Schroeder and A. Merkel

Tojflová, Marie January 2011 (has links)
This thesis concerns German foreign policy towards Russia during the governments of G. Schroeder and A. Merkel with a view to analyzing this policy from a number of perspectives. The first objective is to introduce an analysis of German-Russian relations in the areas of international politics, security, economy and energy policy from 1998 to the present. The second objective is to compare the approaches of both chancellors in foreign policy and identify whether a certain continuity in German foreign policy vis-á-vis Russia has been preserved or whether the policy has been modified, and if so, in what areas.
9

Becoming Other: Virtual Realities in Contemporary Science Fiction

Franks, Jamie N 17 March 2015 (has links)
The purpose of this thesis was to explore the boundary between human and other created by virtual worlds in contemporary science fiction novels. After a close reading of the three novels: Surface Detail, Existence, and Lady of Mazes, and the application of contemporary literary theories, the boundary presented itself and led to the discovery of where the human becomes other. The human becomes other when it becomes lost to the virtual world and no longer exists or interacts with material reality. Each of the primary texts exhibits both virtual reality and humanity in different ways, and each is explored to find where humanity falls apart. Overall, when these theories are applied to real life there is no real way to avoid the potential for fully immersive virtual worlds, but there are ways to avoid their alienating effects.
10

Development and Characterization of an Underwater Acoustics Laboratory Via in situ Impedance Boundary Measurements

Vongsawad, Cameron Taylor 20 December 2021 (has links)
Modeling underwater acoustic propagation comes with a variety of challenges due to the need for proper characterization of the environmental conditions. These conditions include ever changing and complex water properties as well as boundary conditions. The BYU underwater acoustics open-air tank test-bed and measurement chain were developed to study underwater acoustic propagation within a controlled environment. It was also developed to provide ways to test and validate ocean models without the high cost associated with obtaining open ocean measurements. However, tank measurements require additional characterization of boundary conditions associated with the walls of the tank which would not be present in an open ocean. The characterization of BYU's underwater acoustic tank included measuring the calibrated impulse response of the tank through frequency deconvolution of sine swept signals in order to determine the frequency dependent reverberation time through reverse Schroeder integration. The reverberation time allows for calculating the frequency dependent spatially averaged acoustic absorption coefficient of the tank enclosure boundaries. The methods used for this study, common to room acoustics, also yield insights into the Schroeder frequency limit of the tank as well as validate models used for quantifying the speed of sound in the tank. The acoustic characterization was validated alongside predicted values and also applied to a tank lined with anechoic panels in order to improve the potential for modeling the tank as a scaled open ocean environment. An initial investigation into effective tank models evaluated the idealized rigid-wall and pressure-release water-air boundary model, a finite-impedance boundary model applying the measured acoustic boundary absorption and a benchmark open ocean model known as ORCA in order to determine potential tank model candidates. This study demonstrates the efficacy of the methodology for underwater acoustic tank characterization, provides a frequency dependent acoustic boundary evaluation from 5-500 kHz, and provides an initial comparison of tank models with applied characterization.

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