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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.
81

A construção da casa / A construção da casa

Osses, Patricia Andrea Soto 01 July 2010 (has links)
Esta dissertação consiste em uma reflexão sobre a produção visual realizada, entre os anos de 2007 e 2009, em torno do tema de duas casas, uma no Chile e outra na Inglaterra, aqui denominadas Casapina e Johns House. A produção de trabalhos em artes visuais se dá a partir de relações possíveis entre poética, sensação, habitar e deslocamento. A residência em cada uma das casas foi estabelecida durante alguns meses, para a realização de projetos e trabalhos em fotografia, vídeo, instalação, performance e som. O estudo e a pesquisa de construções literárias, em forma de contos e romances, se deu paralelamente ao processo de criação. Buscou-se uma reconstrução do sentido e do significado das casas pelos trabalhos lá realizados. Como resultado, são aqui apresentados os trabalhos realizados nas duas casas, em sua totalidade. Em cada casa, uma obra foi escolhida como pilar das discussões e temas aqui presentes e são apresentados na sua íntegra, em 2 DVDs anexos contendo os filmes El Tango del Pasillo e Johns House. / This dissertation consists on a discussion about the visual production made, from 2007 to 2009, around the theme of two houses, one in Chile and in another in England, here named Casapina and Johns House. The production of works in visual arts comes from possible relationships between poetic, sensation, to inhabit and displacement. The residence in each house was set for a few months for the completion of projects and works in photography, video, installation, performance and sound. The study and research of literary constructions, in the form of short stories and novels, occurred alongside the creation process. It was sought a reconstruction of meaning and significance of the houses by the work performed there. As a result, here are presented studies on two houses in its entirety. In each house, a work was chosen as a pillar of the discussions and themes presented here; they follow in Annex as 2 DVDs, containing the movies El Tango del Pasillo and Johns House.
82

Millimeter wave radio channel characterization and site-specific simulation for 5G systems / Caractérisation et simulation des canaux de propagation en bande millimétrique pour la 5G

Baldé, Mamadou Dialounké 19 December 2017 (has links)
Cette thèse a apporté une contribution au défi de la caractérisation des canaux radios en bandes millimétriques ainsi que la validation d'un outil de simulation déterministe à travers un grand nombre de campagnes de mesures réalisées dans divers scénarios représentatives. Des questions de recherche liées à la caractérisation des canaux radio en bandes millimétriques et sa prédiction à travers un outil de simulation déterministe ont été abordées. Fournir des résultats précis et reproductibles est nécessaire dans le développement d'un système de communication. Ce défi peut être relevé en réalisant des campagnes de mesures qui capturent la réalité du canal de propagation constituant le point de départ. Dans cette thèse, les principales motivations scientifiques derrière ces campagnes de mesures étaient d'étudier la variabilité dans le temps et l'effet de l'environnement sur le canal de propagation dans les bandes millimétriques. Les bandes de fréquences adressées dans cette thèse sont identifiées comme étant importantes par l'UIT en vue d'un futur déploiement de la 5G à savoir 15, 28, 32 et 83 GHz. Les environnements considérés sont une conférence room, bureau, bibliothèque et micro-cellulaire. Les campagnes de mesures ont été menées en utilisant un sondage de canal fréquentiel avec l'utilisation d'un analyseur de réseau. L'exploitation des résultats de mesures ont permis d'apporter des éléments de réponses concernant le canal de propagation dans ces bandes de fréquences. D'autre part, les données de mesures ont été utilisés pour évaluer les performances et contribuer à la calibration d’un simulateur de canal radio à tracé de rayons (RT) reposant sur une approche déterministe. Le simulateur de canal déterministe utilisé dans cette thèse incorpore les mécanismes de propagation tels que le LOS, la réflexion et la diffraction. Le RT a permis de prédire le canal de propagation dans les bandes millimétriques avec une concordance acceptable avec les données de mesures. Ces résultats démontrent que le canal de propagation en bandes millimétriques a pour avantage d'être prédit avec de simple outil déterministe. / This thesis has contributed to the challenge of the radio channel characterizations in millimeter wave bands as well as the validation of a deterministic simulation tool through a large number of measurement campaigns carried out in various representative scenarios. Research questions related to the characterization of radio channels in millimetric bands and its prediction through a deterministic simulation tool were discussed. Providing accurate and repeatable results is necessary for the development of a communication system. This challenge can be meet by conducting measurement campaigns that capture the reality of the propagation channel and therefore constituting the starting point. In this thesis, the main scientific motivations behind these measurement campaigns were to study the time variability and the effect of the scattering environment of the propagation channel in the millimetric bands. The frequency bands addressed in this thesis are identified as important by the ITU for a future deployment of 5G, namely 15, 28, 32 and 83 GHz. The environments considered are a conference room, office, library and microcellular. The measurement campaigns were conducted using a frequency channel sounding technique with the use of a vector network analyzer. The exploitation of the measurement data provided some answers about the radio chennel propagation in these frequency bands. On the other hand, the measurements data were used to evaluate the performance and to contribute to the calibration of the ray-tracing tool (RT) based on a deterministic approach. The RT used in this thesis incorporates propagation mechanisms such as LOS, reflection and diffraction. The RT predicted the propagation channel in the millimeter bands with an acceptable level of agreement with respect to the measurement data. These results demonstrate that the propagation channel in millimetric bands has the advantage of being predicted with a simple deterministic tool.
83

Consumption factor and millimeter-wave channel measurements

Murdock, James Nelson 17 February 2012 (has links)
This thesis describes fundamental approaches to quantify rate versus power consumption tradeoffs for cascaded communication systems. The discussion is bolstered by a large number of in-situ channel measurements, which are used in discussions of the power consumption of future massively broadband cellular systems. Chapter one provides an introduction. Chapter two discusses power consumption trends in modern communication systems. Chapter three introduces the consumption factor framework. Chapter four discusses the channel measurement campaign. Chapter five concludes the thesis, and uses the measurement results to estimate power consumption and capacity of future cellular systems. In addition, chapter five extends the consumption factor theory and draws fundamental conclusions about the energy price per bit for a general cascaded communication system. / text
84

Towards a comprovisation practice : a portfolio of compositions and notations for improvisations

Papageorgiou, Dimitris January 2017 (has links)
This thesis explores the interplay between repeatability and contingency in a series of instrumental and electro-instrumental compositions, through a practice that involves the devising and development of unique notational strategies and the use of bespoke real-time digital signal processing software. In particular, this study examines the praxis of comprovisation, i.e. practices situated between the poles of composition and improvisation, and it is framed by three main research topics: 1. An exploration of musical time and form as components of a dynamic system between events and musical gestures, involving structures of variable and/or indeterminate temporal durations. 2. An investigation of the ways in which the temporal organization and the in-time trópos (τρόπος - ”way, mode, modality, manner”) of an improvisational performance-practice for solo violin can be transduced into the symbolic level so as to be explored as compositional material. 3. An examination of the conditions in which Middle Eastern makam music composition and improvisation traditions can inform the development of contemporary notational devices for a comprovisation practice involving other performers. In addition to the scores, software, and recordings of the compositions, a relevant portfolio of recorded solo-violin improvisations and two published papers examining the above topics are included to further illustrate the discussion.
85

Assessing the performances and optimizing the radar sounder design parameters for the EJSM mission (Ganymede and Europa) / L’étude des performances et le dimensionnement du radar pénétrateur pour la mission EJSM (Ganymède et Europa)

Berquin, Yann 27 February 2014 (has links)
On se propose dans un premier temps d'étudier des jeux de données topographiques sur la lune glacée de Jupiter Ganymède et d'estimer l'impact de la topographie sur les performances du futur radar sondeur. Les principaux résultats sont présentés dans [1]. Une seconde partie est dédiée à l'expression mathématique du problème direct du sondage radar planétaire (physique et instrumentation). On rappelle ainsi comment dériver à partir des formulations de Stratton-Chu les formulations volumiques classiques et surfaciques (i.e. Huygens-Fresnel). On s'attache ensuite à détailler un algorithme performant basé sur la formulation surfacique pour simuler des échos radar à partir d'une surface planétaire maillée. Cette approche est largement inspirée par le travail de J.-F. Nouvel [2]. Une troisième partie s'intéresse à l'inversion des paramètres géophysiques de surface à partir des mesures radar. On écrit ainsi le problème dans un cadre probabiliste (c.f. [3]) et on présente trois grandes familles d'algorithmes : (i) une approche avec une linéarisation du problème, (ii) une approche itérative basée sur une méthode de gradient et (iii) une approche statistique pour estimer les densités de probabilités a posteriori. Ces algorithmes sont appliqués à des jeux de données synthétiques pour illustrer leurs performances. [1] Y. Berquin, W. Kofman, A. Herique, G. Alberti, and P. Beck. A study on ganymede's surface topography: Perspectives for radar sounding. Planetary and Space Science, (0), 2012. [2] J.-F. Nouvel, A. Herique, W. Kofman, and A. Safaeinili. Radar signal simulation: Surface modeling with the Facet Method. Radio Science, 39:RS1013, February 2004. [3] A. Tarantola. Inverse problem theory and methods for model parameter estimation. SIAM, 2005. / The manuscript details the work performed in the course of my PhD on planetary sounding radar. The main goal of the study is to help designing and assessing the sounding radar performances. This instrument will be embarked on the ac{ESA}'s large class mission ac{JUICE} to probe Jupiter's environment and Jupiter's icy moons Callisto, Ganymede and Europa. As an introduction to the problem, a study on Ganymede's surface ac{DEM} and its implications with regard to the radar performances was performed. The results of this work put forward issues due to a hostile environment with important surface clutter which eventually lead to a decrease in the radar signal bandwidth to 8--10 MHz. A first section is then dedicated to the formulation of the direct problem of sounding radar with a focus on surface formulations. This section eventually leads to a novel algorithm for radar surface echo computation from meshed surfaces which proves to be both efficient and accurate. A second section studies the possibility to use surface formulation to recover geophysical surface parameters from sounding radar data. For that purpose, three main approaches are discussed namely (i) a linear approach, (ii) a gradient-based approach and (iii) a statistical approach. These techniques rely on a probabilistic view of the inverse problem at hand and yield good result with different setups. Although we mainly focus on surface reflectivity, we also discuss surface topography inversion. Finally, a last section discusses the work presented in the manuscript and provides perspectives for future work.
86

Refração Sísmica Profunda no Setor Sudeste da Província Tocantins / Deep Seismic Refraction on Southestearn Sector of the Tocantins Province

Fábio André Perosi 31 July 2000 (has links)
O presente trabalho de mestrado está inserido nos estudos de refração profunda do Projeto Temático 'Estudos Geofísicos e Modelo Tectônico dos Setores Central e Sudeste da Província Tocantins, Brasil Central'. Nesses estudos foram levantadas três linhas de refração de aproximadamente 300 km de extensão, duas no setor Central da Província Tocantins e uma no setor Sudeste, que é o objeto de estudo deste trabalho. Foram utilizados 111 sismógrafos digitais SGR pertencentes ao programa PASSCAL, instrumentos auxiliares do USGS, e 13 sismógrafos digitais e instrumentos auxiliares do IAG/USP. A linha sísmica teve aproximadamente 300 km de extensão com pontos de registro separados a cada 2,5 km, distribuídos ao longo de estradas principais e secundárias. A cada 50 km, aproximadamente, foi realizada uma explosão, nas explosões dos extremos da linha foram utilizados 1000 kg de explosivo e para a explosão central uma carga de 500 kg. Para a determinação das coordenadas geográficas dos pontos de tiro e de registro, foi utilizado o método diferencial com medidas de GPS. O principal objetivo deste trabalho foi obter como produto final um modelo de velocidades sísmicas contendo as características físicas das principais descontinuidades na crosta terrestre e no manto superior. Para análise e processamento dos dados foram utilizados os pacotes SAC, SU, SEIS. Para a modelagem foram utilizados a teoria do raio e a elaboração de sismogramas sintéticos, do pacote SEIS. Para a elaboração do modelo final foram utilizados os dados das explosões dos pontos extremos e central, tendo em vista que devido a problemas técnicos não foram registrados os sinais das outras 4 explosões. Além disso, as explosões registradas não apresentaram sinais claros em toda a extensão da linha. Devido a tudo isso e considerando as unidades geológicas presentes na região de estudo são sugeridos três modelos de velocidades sísmicas. O primeiro modelo refere-se ao tiro direto (EX31) localizado no extremo sudoeste da linha, sobre a Bacia do Paraná. Para este modelo obteve-se para superfície (0 km) a velocidade inicial de 2 km/s (coberturas); para a profundidade de 0,086 km a velocidade inicial é de 5,15 km/s (basalto); para a profundidade de 0,350 km obteve-se a velocidade inicial de 4,6 km/s (arenito - camada de baixa velocidade); para profundidade de 0,650 km a velocidade inicial é de 5,75 km/s e para profundidade de 4 km obteve-se a velocidade inicial de 6,07 km/s. O segundo modelo refere-se ao tiro reverso (EX34) localizado no centro da linha sobre granitóides do Grupo Araxá. Para este modelo obteve -se para superfície (0 km) a velocidade inicial de 2 km/s; para a profundidade de 0,06 km a velocidade inicial é de 5,69 km/s e para a profundidade de 0,860 km obteve-se a velocidade inicial de 6,25 km/s. Finalmente, o terceiro modelo refere-se ao tiro direto para toda a extensão da linha (300 km). Este modelo foi definido a partir de fases secundárias lidas nos registros e modelos anteriores propostos na literatura. Da superfície até os 4 km iniciais de profundidade este modelo é igual ao primeiro, para uma profundidade de 20 km obteve-se a velocidade inicial de 6,70 km/s e para uma profundidade de 40 km a velocidade é de 8,00 km/s (descontinuidade de MOHO). / This work to fulfil the degree of Master of Sciences is inserted among the deep seismic refraction studies of the Thematic Project 'Geophysical Studies and Tectonic Model of the Tocantins Province Central and Southeast Sectors, Central Brazil'. Three refraction lines, of around 300 km long each, were deployed, two of them in the Central sector and the other in the SE sector, that is subject of the present work. The equipment used in this experiment was composed by 111 SGR digital seismographs belonging to the PASSCAL Program. Complemented with auxiliary instruments from USGS and 13 seismographs belonging to IAG/USP. The space among the recording points was 2.5 km, which were located along main and secondary roads. Every 50 km was fired an explosion with 1000 kg of emulsion in each extreme and 500 kg in the central point. The geographical co-ordinates were determined by using the GPS differential method. The main objective of this work is to obtain as a final product a seismic velocity model with the physical characteristics of the main discontinuities in the crust and upper mantle. The packages SAC, SU and SEIS were used to perform the data analysis and processing. To carry on the modelling were used the ray theory and the synthetic seismograms construction, belonging to the SEIS package Data from the extreme and middle points of the seismic line were used to elaborate the final model, considering that due to technical problems signals from the other four explosions were not recorded. Apart from that, the recorded explosions did not present clear signals all along the extension of the line. Due to these facts, and considering also the geological units present in the studied region, are suggested three seismic velocity models. The first model is referred to the direct shot (EX31), which is localised in the Southwest extreme of the line on the Parana Basin province. In this model we obtained the P wave velocity (VP) of 2 km/sec at the surface, corresponding to the unconsolidated sediments and soil on the top of that basin. At a depth of 86 m we found VP of 5,15 km/sec and at a depth of 350 m the velocity VP of 4,6 km/sec, corresponding to the basalt and sand layers of the Parana Basin. Underlying them, at 650 m of depth we found the basement with VP of 5,75 km/sec and finally at a depth of 4 km there is a layer with VP of 6,07 km/sec, corresponding to a typical upper crust P wave velocity. The second model corresponds to the reverse shot (EX34) that is localised in the middle point of the line on the granitoides of the Araxa Group. For this model we obtained VP of 2 km/sec for the superficial layers, then at a depth of 60 m was obtained V P of 5,69 km/sec and for a depth of 860 m the value of V P is 6,25 km/sec. Finally, the third model belongs to the whole line section (300 km) from the direct shot (EX31). This model was obtained by using the arrivals of secondary phases and the results of models proposed in other works. From the surface down to 4 km of depth this model is similar to the first one. At 20 km of depth there is a layer with VP of 6,70 km/sec, corresponding to the lower crust, with Moho at a depth of 40 km with VP of 8,00 km/sec.
87

Development of a three-dimensionalthermal analysis tool for sounding rockets / Utveckling av ett tredimensionellt termiskberäkningsverktyg för sondraketer

Ryman, André, Wahlberg, Andreas January 2014 (has links)
This thesis has been performed in collaboration with the Swedish Space Corporation at the department Science Services. SSC provides services in the areas of spacecraft subsystems, ground stations and sounding rockets to enable governments, companies and research institutes to benefit from space. Science Services are responsible for sounding rocket flight missions allowing customers to perform research in a microgravity environment. Currently, they have good knowledge how to design the sounding rockets experiment modules to minimize thermal effects within the system. However, no computational models are available to evaluate and verify the thermal heat transfer inside of the modules and as such the systems are designed primarily based on previous experience. The main purpose of this thesis was to develop a thermal computational model, which would work as a basis for designing experiment modules. The model would be used in an early stage of the design process before CAD parts have been designed. This required a flexible model allowing the user to evaluate different types of components and configurations. A finite element method (FEM) was used to perform heat transfer calculations in MATLAB. The development process was divided into three stages, which reduced the complexity of the problem formulation. The first version was made to approximate heat transfer solution in three dimensions using the Galerkin’s weighed residuals method. The second version was made to implement the dynamic environment occurring during flight missions. Based on the external environment, the dynamic process was divided into phases with different boundary conditions. In the final version internal convection, conductivity between air elements and a GUI was developed. The versions were verified with COMSOL (2013) and previous measured flight data. The results from the simulations showed that the internal convection coefficient and the element’s conductivity have a great impact on how the heat is distributed inside th e modules. A low convection will lead to internal temperature peaks, which can cause damage to sensitive experiment equipment. Also, the results indicated that the external environment does not have a significant impact on the internal temperatures. The assumptions made and recommendations are also covered in this thesis. Keywords: Three-dimensional heat transfer, Finite element method, Sounding rocket, Computational simulation / Detta examensarbete har utförts i samarbete med Swedish Space Corporation på avdelningen Science Services. SSC är ett svenskt företag verksam inom rymdtekniksektorn som erbjuder myndigheter, företag och forskarlag runt om i världen möjlighet att dra nytta av rymden. Avdelningen Science Service är ansvariga för utvecklig samt uppskjutning av sondraketer. I dagsläget finns en god kunskap hur sondraketens experimentmoduler ska konstrueras för att minimera den termiska påverkan i systemen. Dock existerar ingen beräkningsmodell för att undersöka värmeutvecklingen och temperaturer i dessa experimentmoduler, all kunskap inom detta område är baserad på tidigare erfarenheter. Syftet med detta examensarbete var att utveckla en termisk beräkningsmodell som kan användas som underlag när nya experimentmoduler konstrueras på SSC. Användningsområdet för modellen var avsett i ett tidigt skede i produktutvecklingsprocessen, innan CAD-modeller eller dylikt har framställts. Därav efterfrågades en flexibel modell där användaren kan undersöka olika typer av kompententer och konfigurationer. Den Finita elementmetoden (FEM) har används för att skapa en termisk beräkningsmodell i MATLAB. Utvecklingen delades upp i tre steg, eller tre programversioner, vilket bidrog till att frågeställningens komplexitet reducerades. Första programversion genomfördes för att approximera värmeflöden och temperaturer i tre dimensioner med hjälp av Galerkins viktade residualmetod. I den andra programversionen implementerades den dynamiska omgivningen som uppstår under flygning. Baserat på den yttre påverkan från det dynamiska förloppet delades flygningen in i olika faser, alla med skilda randvillkor. I den slutliga programversionen implementerades intern konvektion, strålning och ett grafiskt användargränssnitt. Samtliga versioner verifierades numerisk med hjälp av COMSOL (2013) . Resultatet från beräkningsmodellen påvisade att den interna konvektionskoefficient samt konduktiviteten hos element har stor inverkan på hur temperaturen fördelas inuti modulen. Resultaten indikerade även att den yttre miljön inte har en signifikant betydelse för dessa temperaturer. De antaganden som utförts samt förbättringsförslag avhandlades även i detta arbete. Nyckelord: Värmeledning, tredimensionellt, Finita elementmetoden, Sondraket, Simulering
88

Development of an Index for Concrete Bridge Deck Management in Utah

White, Ellen T. 14 July 2006 (has links) (PDF)
The purpose of this research was to develop a new index for concrete bridge deck management in Utah. Data were collected in the summer of 2005 from 15 concrete bridge decks in the vicinity of Salt Lake City. The decks ranged from 2 to 21 years in age and were all constructed using epoxy-coated rebar. Visual inspection, sounding, Schmidt hammer testing, half-cell potential testing, and chloride concentration testing were performed on six 6-ft by 6-ft test areas randomly distributed within the single lane closed to traffic on each deck, and testing protocols followed American Society for Testing and Materials standards to the extent possible. Collected data were analyzed using statistics, and age, cover, and half-cell potential were ultimately selected for inclusion in a new Utah Bridge Deck Index (UBDI); these variables effectively reflect chloride-induced corrosion mechanisms active on Utah bridge decks, are highly correlated to delamination distresses, and are relatively easy to measure compared to chloride concentration. At the request of Utah Department of Transportation (UDOT) personnel, the UBDI equation was structured around a deduct system using a 100-point scale similar to the sufficiency rating system, in which a perfect bridge deck receives a score of 100. Coefficients were selected based largely on the judgment of the researchers and the UDOT personnel involved in the research, and threshold values for maintenance, rehabilitation, and replacement (MR&R) options were specified to be the same as those associated with the standard sufficiency ratings. The UBDI and corresponding MR&R recommendation were then provided for each of the bridge decks tested in this research; nine of the decks are recommended for preventive treatment, and six are recommended for rehabilitation. In addition, the possibility of treatment applications was considered, leading to required adjustments in the UBDI calculation; the treatment options that were considered include an epoxy seal, an HPC overlay, and an asphalt membrane overlay. Four case scenarios were developed to demonstrate the response of the revised UBDI equation to these treatments. Finally, as aids for UDOT personnel implementing this research, charts were created to facilitate rapid determination of the required number of half-cell potential and concrete cover measurements for different levels of reliability and tolerance. The UBDI developed in this research is recommended for implementation by UDOT personnel as a tool for optimizing the timing of MR&R treatments on concrete bridge decks similar to those evaluated in this project. In measuring cover and half-cell potential values, UDOT personnel should utilize the sampling guidelines presented in this report to ensure adequate characterization of each deck. Furthermore, to facilitate the inclusion of treatment effects in the UBDI, UDOT personnel should establish a policy of recording the types and dates of all MR&R treatments applied to bridge decks. As performance data are collected for specific treatments over time, the treatment lives proposed in this research for epoxy seals, HPC overlays, and asphalt membrane overlays should be revised as needed, and information for other treatments may be added. In addition, to maximize the predictive capabilities of the UBDI, more accurate relationships between half-cell potential values and deck age should be developed for estimating future deck condition.
89

Condition Analysis of Concrete Bridge Decks in Utah

Tuttle, Robert S. 15 June 2005 (has links) (PDF)
Concrete bridge decks in Utah are experiencing observable deterioration due primarily to freeze-thaw cycles and the routine application of deicing salts during winter maintenance activities. Given the need for increasingly cost-effective strategies for bridge deck maintenance, rehabilitation, and replacement (MR&R), the Utah Department of Transportation (UDOT) initiated this research to ultimately develop a protocol offering guidance as to whether deteriorated bridge decks should be rehabilitated or replaced. While threshold values for various non-destructive condition assessment methods were proposed in earlier UDOT research, this work focused on implementing the recommended test criteria. Twelve bridges were identified by UDOT engineers for inclusion in the study, and data were collected from each deck to determine whether the bridge decks warranted rehabilitation or replacement based on the proposed threshold values. Several evaluation techniques were employed to assess concrete bridge deck condition, including visual inspection, hammer sounding and chaining, dielectric measurements, ground-penetrating radar imaging, resistivity testing, half-cell potential testing, and chloride concentration testing. The condition assessment testing confirmed that chloride-induced corrosion of reinforcing steel is the primary mechanism of deck deterioration and that inadequate cover over the upper steel mat facilitated accelerated corrosion damage in many instances. The bridge deck condition analyses produced from the results of non-destructive testing were compared to the visual inspection ratings assigned to each deck by UDOT. Concrete bridge deck condition data should be collected regularly through inspection and monitoring programs to facilitate prioritization of MR&R strategies for individual bridges and to evaluate the impact of such strategies on the overall condition of the network. Performance indices based on selected condition assessment parameters should be developed for use in bridge management activities, and mathematical deterioration models should be calibrated in order to forecast both network-level and project-level conditions and predict funding requirements for various possible MR&R strategies. Further research, including statistical analyses of the data presented in this report, should be completed to develop relevant mathematical deterioration models for predicting the service lives of concrete bridge decks in Utah.
90

[en] MEASUREMENT AND ANALYZE OF UWB INDOOR CHANNEL TEMPORAL DISPERSION IN SEVERAL ENVIRONMENT TYPES / [pt] MEDIDAS E ANÁLISE DA DISPERSÃO TEMPORAL DO CANAL DE PROPAGAÇÃO UWB INDOOR EM VÁRIOS TIPOS DE AMBIENTES

FABRICIO JOSE BRITO BARROS 16 December 2005 (has links)
[pt] Este trabalho apresenta a análise das características de dispersão temporal do canal de propagação banda ultra larga (UWB) feitas a partir da técnica de sondagem em freqüência na banda de 850MHz em sete diferentes ambientes Indoor. Nestes ambientes os parâmetros de dispersão temporal dados pelo retardo médio, retardo RMS e banda de coerência são obtidos. Uma análise adicional sobre a perda de propagação e sobre a robustez do sinal UWB a desvanecimento de pequena escala é também realizada. / [en] This work presents an analysis of the ultra wideband (UWB) channel temporal dispersion characteristics evaluated from the frequency sounding technique over a bandwidth of 850MHz at seven different indoor environment. In each environment, the channel temporal dispersions parameters were assessed in terms of mean delay, delay spread and coherence bandwidth. An additional analysis related to path loss and UWB robustness was also evaluated.

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