Approved for public release, distribution is unlimited / Direct-Sequence Spread Spectrum (DSSS) modulation is being advanced as the physical-layer basis for Seaweb undersea acoustic networking. DSSS meets the need for channel tolerance, transmission security, and multi-user access. This thesis investigates the performance of subspace-decomposition blind-equalization algorithms as alternatives to RAKE processing of DSSS signals. This approach is tailored for superior performance in time-dispersive and frequency-dispersive channels characteristic of ocean acoustic propagation. Transmitter and receiver structures are implemented in Matlab and evaluated with a statistics-based model of a doubly spread channel with additive noise. Receiver performance is examined using Monte Carlo simulation. Biterror rates versus signal-to-noise ratio are presented for various multipath assumptions, noise assumptions, and receiver synchronization assumptions. / Lieutenant, Hellenic Navy

Orientador: Chang Hung Kiang / Banca: Amauri Antonio Menegário / Banca: Alex Vladmir Krusche / Banca: Ene Glória da Silveira / Banca: Roberto Naves Domingos / Resumo: O objeto de estudo é a estimativa de fluxo de CO2 e CH4 em ambiente aquático, quantificado por medidas diretas com câmara flutuante para o dióxido de carbono e da pressão parcial do CO2 e CH4 (PCO2 e PCH4). A área de estudo localiza-se na Bacia do Ji-Paraná, integrante da Região Hidrográfica do rio Madeira - RO. A amostragem foi mensal, de maio 2006 a fevereiro 2008. Através da amostragem com câmara flutuante foi possível calcular o coeficiente de troca gasosa (K), expresso como K600, para todos os rios amostrados, cuja média geral foi de 23,5 ± 8,5 cm h−1 para o CO2 e 28,8 ± 10,4 cm h−1 para CH4. Os valores estimados para fluxo de CO2 com a câmara foram de 1.845,1 mg C m−2 d−1, por equilíbrio trocas gasosas de 1.690,1 mg C m−2 d−1; e de 24,3 mg C m−2 d−1 para CH4. O período seco apresentou menor fluxo de CO2 em relação à cheia. Para CH4 o fluxo apresentou variabilidade temporal. Os resultados evidenciam que a emissão de gases pelo sistema aquático é um importante integrante do ciclo do carbono e que o fluxo de CO2 esta relacionado ao comportamento hidrológico sazonal característico para a Amazônia. / Abstract: The object of study is the estimated flow of CO2 and CH4 in the aquatic environment, quantified by direct measurements with floating chamber for carbon dioxide and partial pressure of CO2 and CH4 (PCO2 and PCH4). The study area is located in Ji-Parana River Basin, river basin of the river Madeira - RO. Sampling was monthly, from May 2006 to February 2008. By sampling with floating chamber was possible to calculate the gas exchange coefficient (K), expressed as K600, for all the rivers sampled, whose overall average was 23,5 ± 8,.5 cm h-1 for CO2 and 28, 8 ± 10.4 cm h-1 for CH4 The estimated values for flow of CO2 with the chamber were 1.845,1 mg C m-2 d-1, for gas exchange balance of 1.690,1 mg C m-2 d-1, and 24,3 mg C m -2 d-1 for CH4. The falling water had lower flow of CO2 in relation to the rising water. CH4 flow presented to the temporal variability. The results show that the emission of gases by the water system is an important part of the carbon cycle and the flow of CO2 is related to seasonal hydrological behavior characteristic for the Amazon. / Doutor

O presente trabalho tem como objetivo apresentar o resultado da análise e identificação de padrões e comportamentos de postagens na rede social Twitter monitorando um termo específico em um período definido de tempo. Após a extração e tratamento dos dados obtidos do Twitter, explicitando dentre as postagens quais são oriundas de usuários geradores de notícias, foram analisadas informações de topologia da rede de usuários do experimento, inclusive com o detalhamento das informações de propagação e duração das postagens: dados e comportamentos os quais buscamos reproduzir utilizando simulação por agentes / The present work aims to present the result of the analysis and identification of patterns and behaviors of Twitter posts monitoring a specific term in a period. After the extraction and treatment of the data obtained from Twitter, emphasizing among the posts which are generated from news agency users, were analyzed the topology information about the network of users of the experiment, including details of propagation information and duration of the posts: data and behaviors that we seek to reproduce using agent simulation

O presente trabalho teve por objetivo registrar os diálogos entre os diferentes campos de conhecimentos, que serviram de postulado para orientar as ações do projeto de pesquisa e extensão, Avaliação Técnica, Econômica e Socioambiental da Atividade Artesanal no Quilombo de Ivaporunduva, Vale do Ribeira (SP), bem como aportar as possíveis contribuições deste Projeto para estreitar o diálogo entre o conhecimento científico e os saberes originários das experiências e das práticas dos componentes do Grupo de Artesanato da comunidade de Ivaporunduva, localizada no município de Eldorado, Vale do Ribeira, estado de São Paulo, Brasil. Realizou-se análise de documentos produzidos pelo Projeto; foram feitas entrevistas com técnicos, professores e/ou pesquisadores e alunos, e com membros do Grupo de Artesanato; além disso, realizaram-se observações das ações do Projeto na academia e na comunidade. Verificouse que as atividades desenvolvidas no âmbito acadêmico contribuíram para construção gradual da prática inter e/ou transdisciplinar, na medida em que as ações do Projeto necessitaram reunir diferentes áreas do saber para resolver dificuldades técnicas encontradas para a consolidação da atividade. Observou-se ainda que há graus de comprometimento variados, entre os diferentes profissionais, de campos disciplinares distintos. Contudo, a abertura por parte do corpo discente vem sendo um veículo importante para a interlocução de saberes, que tem estimulado o exercício da prática inter e/ou transdisciplinar. Constatou-se que a Universidade, enquanto produtora e disseminadora de conhecimentos requer mudanças, no sentido de promover a aproximação dos campos disciplinares, tendo em vista a construção de um conhecimento integrado. Já no âmbito comunitário foi possível constatar que, as ações do Projeto contribuíram para aproximar os saberes técnico-científicos das experiências e das práticas do Grupo de Artesanato, visando a resolução de problemas de ordem técnica, de comercialização e de gestão que inviabilizam a consolidação da atividade artesanal naquela comunidade. Conclui-se, portanto, que a interlocução entre diferentes campos do conhecimento, bem como o diálogo entre o conhecimento científico e outros saberes pode contribuir para o debate epistemológico e, por conseguinte para construção de um conhecimento integrador. / The aim of this research work was to register the dialogues between the different knowledge fields, which served to direct the actions of the research and extension project, Technical, Economic, Social and Environmental evaluation of the Handicraft activities inside the Ivaporunduva Quilombo, Vale do Ribeira (SP), as well as to signed the possible contributions of this project to close the dialogue between scientific knowledge and knowledge came from the experience of the members of the Ivaporunduva community, located in El Dorado, Vale do Ribeira, São Paulo State, Brazil. The documents elaborated by the project were analyzed; as well as were made interviews with technicians, professors and/or researchers and students involved in the project, and with the members of the Handicraft Group. Besides, observations of the project actions inside the academy and the community were made. This analysis checked out the activities developed in the academic sphere that contributed to the grade construction of an inter-disciplinary and/or trans-disciplinary practice, since the project actions needed to bring together different knowledge areas to solve technical difficulties to allow the consolidation of the activity. Hence, this research work, noticed the varied grades of commitment existing among the different professionals from different subject fields. However, the open attitudes of the university students have been an important vehicle to the knowledges dialogue, what have been stimulating the inter-disciplinary and/or trans-disciplinary practice. There were realized that the university, as producer and spreader of knowledge, needs changes, to promote the approximation between subject fields, having in view the construction of an including knowledge. Inside the communitarian sphere was possible to realize that the project actions contributed to approximate the technical-scientific knowledge and the Handicraft Group activities, looking to solve technical, sale and management problems that produced difficulties to establish the craftwork activity with in the community. Therefore, this conclude that the dialogue between different knowledge fields as well as the dialogue between the scientific knowledge and other kinds of knowledge could contribute to the epistemic debate and, therefore, to the construction of an including knowledge.

Time Average Fourier Telescopy (TAFT) has been proposed as a means for obtaining high-resolution, diffraction-limited images over large distances through ground-level horizontal-path atmospheric turbulence. Image data is collected in the spatial-frequency, or Fourier, domain by means of Fourier Telescopy; an inverse two dimensional Fourier transform yields the actual image. TAFT requires active illumination of the distant object by moving interference fringe patterns. Light reflected from the object is collected by a “light-bucket” detector, and the resulting electrical signal is digitized and subjected to a series of signal processing operations, including an all-critical averaging of the amplitude and phase of a number of narrow-band signals. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Une communication est impulsive chaque fois que le signal portant des informations est intermittent dans le temps et que la transmission se produit à rafales. Des exemples du concept impulsife sont : les signaux radio impulsifs, c’est-à-dire des signaux très courts dans le temps; les signaux optiques utilisé dans les systèmes de télécommunications; certains signaux acoustiques et, en particulier, les impulsions produites par le système glottale; les signaux électriques modulés en position d’impulsions; une séquence d’événements dans une file d’attente; les trains de potentiels neuronaux dans le système neuronal. Ce paradigme de transmission est différent des communications continues traditionnelles et la compréhension des communications impulsives est donc essentielle. Afin d’affronter le problème des communications impulsives, le cadre de la recherche doit inclure les aspects suivants : la statistique d’interférence qui suit directement la structure des signaux impulsifs; l’interaction du signal impulsif avec le milieu physique; la possibilité pour les communications impulsives de coder l’information dans la structure temporelle. Cette thèse adresse une partie des questions précédentes et trace des lignes indicatives pour de futures recherches. En particulier, nous avons étudié: un système d'accès multiple où les utilisateurs adoptent des signaux avec étalement de spectre par saut temporel (time-hopping spread spectrum) pour communiquer vers un récepteur commun; un système avec un préfiltre à l'émetteur, et plus précisément un transmit matched filter, également connu comme time reversal dans la littérature de systèmes à bande ultra large; un modèle d'interférence pour des signaux impulsifs. / A communication is impulsive whenever the information-bearing signal is burst-like in time. Examples of the impulsive concept are: impulse-radio signals, that is, wireless signals occurring within short intervals of time; optical signals conveyed by photons; speech signals represented by sound pressure variations; pulse-position modulated electrical signals; a sequence of arrival/departure events in a queue; neural spike trains in the brain. Understanding impulsive communications requires to identify what is peculiar to this transmission paradigm, that is, different from traditional continuous communications.In order to address the problem of understanding impulsive vs. non-impulsive communications, the framework of investigation must include the following aspects: the different interference statistics directly following from the impulsive signal structure; the different interaction of the impulsive signal with the physical medium; the actual possibility for impulsive communications of coding information into the time structure, relaxing the implicit assumption made in continuous transmissions that time is a mere support. This thesis partially addresses a few of the above issues, and draws future lines of investigation. In particular, we studied: multiple access channels where each user adopts time-hopping spread-spectrum; systems using a specific prefilter at the transmitter side, namely the transmit matched filter (also known as time reversal), particularly suited for ultrawide bandwidhts; the distribution function of interference for impulsive systems in several different settings.

Esse trabalho objetiva avançar nas pesquisas acerca da difusão da arquitetura moderna brasileira para fora dos grandes centros, descobrindo seus reflexos ante as peculiaridades locais da mesorregião mineira do Triângulo Mineiro e Alto Paranaíba, identificando, além dos seus protagonistas, os vários mecanismos de apropriação da nova linguagem projetual inserida, que também se refletem na produção de novos valores, novas formas, novos procedimentos técnicos e nos diálogos com a produção dos grandes centros. Parte da arquitetura moderna documentada em vinte e uma cidades da mesorregião pelo projeto de pesquisa intitulado \"Documentação da Arquitetura Moderna no Triângulo Mineiro e Alto Paranaíba: História e Preservação\", desenvolvido pelo Núcleo de Pesquisa em Teoria e História da Arquitetura e Urbanismo (NUTHAU), da Faculdade de Arquitetura, Urbanismo e Design da Universidade Federal de Uberlândia (FAUeDUFU). O trabalho foi desenvolvido no curso de mestrado em Teoria e História da Arquitetura e Urbanismo, do Instituto de Arquitetura e Urbanismo da Universidade de São Paulo (IAU/USP), com auxílio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes). / This work, which is entitled \"Modern Architecture in the Triângulo Mineiro and Alto Paranaína region: some indications for the development of an architectural culture\", aims at progressing the research on the spread of Brazilian modern architecture outside major centers, finding out its consequences on local peculiarities of the Triângulo Mineiro and Alto Paranaíba mesoregion and also identifying - in addition to its protagonists -, the numerous mechanisms for appropriation of the new projectual language added, which is reflected in the production of new values, new forms and new technical procedures as well as in the dialogues with production from major centers. Part of the modern architecture was documented in twenty-one mesoregion cities through a research project entitled \"Documentation of Modern Architecture in Triângulo Mineiro and Alto Paranaína: History and Preservation\", undertaken by the Center for Research in Theory and History of Architecture and Urbanism (NUTHAU, in Portuguese), from the School of Architecture, Urbanism and Design at the Federal Univerity of Triângulo Mineiro (FAUeD-UFU, in Portuguese). The work was developed at the Master´s Program in Theory and History of Architecture and Urbanism - Architecture and Urbanism Institute of the University of São Paulo (IAU/USP) with support from CAPES (Coordination for Improvement of Higher Education Personnel).

Made available in DSpace on 2017-07-24T19:45:51Z (GMT). No. of bitstreams: 1 Marilene Probst Novacoski.pdf: 10768451 bytes, checksum: 21533b701fe5ccaf511a5a3d82fe34eb (MD5) Previous issue date: 2017-08-22 / The main purpose of this work was to propose and implement experiments using the Arduino Integrated Plate. The plate was used in Thermodynamics experiments to room temperature measures, in discussions about thermal sensation and heat propagation processes. In the approach of Modern Physics topics, a metal cube was built, similar to the commercial Leslie Cube and other modified. The temperature measurements in real time on the faces of the cube were obtained using the Arduino Integrated plate, NTC temperature sensors and data acquisition system (DAQ PLX). As a result of this work we include: production of a Leslie Cube similar to the traditional, production of a modified cube, where the inner faces have different colors in relation to each other, producing an introductory guide to Arduino and a guide of experiences related to Thermodynamics and Modern Physics. We conclude that the Integrated Arduino board is an important and appropriate tool for the integration of different technologies in high school. / O objetivo principal desta dissertação foi propor e realizar experimentos utilizando a Placa Integrada Arduino. A placa foi utilizada em experimentos de Termodinâmica, para medidas de temperatura ambiente, nas discussões sobre sensação térmica e processos de propagação de calor. Na abordagem de temas de Física Moderna, foi construído um cubo metálico, similar ao Cubo de Leslie comercial e outro modificado. As medidas de temperatura em tempo real nas faces do Cubo, foram obtidas utilizando a Placa Integrada Arduino, sensores de temperatura NTC e o sistema de aquisição de dados (PLX DAQ). Como resultados das atividades desenvolvidas nesta dissertação, podemos citar: produção de um Cubo de Leslie similar ao tradicional, produção de um cubo modificado, onde, as faces internas apresentam cores diferentes uma em relação à outra, produção de um guia de introdução ao Arduino e um roteiro de experiências relacionadas à Termodinâmica e Física Moderna. Concluímos que a Placa Integrada Arduino é uma ferramenta importante e adequada para a inserção de diferentes tecnologias no ensino médio.

Made available in DSpace on 2016-04-26T18:15:16Z (GMT). No. of bitstreams: 1 Grazziani Barreto Colombo.pdf: 2156642 bytes, checksum: 0f096db6f6275455f5fdc82868f3edf5 (MD5) Previous issue date: 2015-08-03 / This research has as object social networks, specifically Facebook, including participations and interactions on the network. The aim is to investigate the phenomenon of the spread of information under the following approach: to participate is to exist. To that end, variables of influence, communication and reputation involved in the spread and in the forms of participation, which qualify the existence of individuals in the network were studied. The issue involved is that user's forms of participation on social networks are in a transitional movement that changes his perception of existence in the digital environment. There is no stability among the types of interactions that generate the spread of information. These forms are linked to the current structures of social networks: if they change, the forms of participation are also changed, and therefore, the feedback from peers and their perception of existence on the network. The spread also depends on the network algorithm, which defines the rules and content distribution thresholds. Thus, for the diffusion to happen, two decision thresholds will be needed: the user's and the algorithm's. The hypothesis is that user participation qualifies its existence on online social networks. To participate is to exist. Through Granovetter's studies - on the forces between the connections of users and decision thresholds in collective participation, Gladwell and Christakis - about the influences of network connections - the project presents theoretical grounds to advance in the understanding of the dissemination of information on social networks. Users' strong ties are crucial cogs to the scope of the two thresholds within the network. The analyzed case is the "Ice Bucket Challenge", a movement in favor of the Amyotrophic Lateral Sclerosis Association (ALSA). It worked as follows: a person would pour a bucket of water with ice on his head and challenge three others to do the same within 24 hours or donate $ 100 to the association. The message reached tens of millions of people and led the Association to raise 45 times more donations than the previous year. The clarification sought about how the spread of information in social networks and its direct relationship with the existence of individuals, makes it possible the raise of new issues and analysis related to algorithms decision thresholds, as well as new definitions of what is to participate of/to belong to a social network / Esta pesquisa tem como objeto as redes sociais, especificamente o Facebook, compreendendo participações e interações na rede. O objetivo é investigar o fenômeno da propagação de informações sob o seguinte ângulo: participar é existir. Para tanto, foram estudadas as variáveis de influência, comunicação e reputação implicadas na propagação e nas formas de participação, as quais qualificam a existência dos indivíduos na rede. A problemática envolvida é que as formas de participação dos usuários nas redes sociais estão em um movimento transitório que altera sua percepção de existência no meio. Não há uma estabilidade entre os tipos de interação que geram a propagação de informação. Essas formas estão ligadas às atuais estruturas das redes sociais: se elas mudam, as formas de participação também se alteram e por consequência o feedback dos pares e a sua percepção de existir na rede. A propagação também depende do algoritmo da rede, que define as regras e os limiares de distribuição de conteúdo. Assim, para que a difusão aconteça, será necessário o alcance de dois limiares de decisão: o do usuário e o do algoritmo. A hipótese é que a participação do usuário qualifica sua existência nas redes sociais on-line. Participar é existir. Através dos estudos de Granovetter sobre as forças entre as conexões dos usuários e dos limiares de decisão em participações coletivas, Gladwell e Christakis sobre as influências das conexões em rede o projeto apresenta bases teóricas para avançar no entendimento da difusão de informações nas redes sociais. Os laços fortes dos usuários são engrenagens fundamentais para o alcance dos dois limiares dentro da rede. O caso analisado é o Desafio do balde de gelo (Ice Bucket Challenge), um movimento em prol da Associação Americana de Esclerose Lateral Amiotrófica (ALSA). A operação funcionava da seguinte forma: uma pessoa derramava um balde de água com gelo sobre a cabeça e desafiava três outras pessoas a fazer o mesmo dentro de 24 horas ou doar US$ 100 para a associação. A propagação atingiu dezenas de milhões de pessoas e fez com que a Associação arrecadasse 45 vezes mais doações que o ano anterior. O esclarecimento que se buscou sobre como a propagação de informações nas redes sociais e sua relação direta com a existência dos indivíduos possibilita levantar novas questões e análises em relação ao limiar de decisão dos algoritmos, bem como as novas definições do que é participar na rede

Une communication est impulsive chaque fois que le signal portant des informations est intermittent dans le temps et que la transmission se produit à rafales. Des exemples du concept impulsife sont : les signaux radio impulsifs, c’est-à-dire des signaux très courts dans le temps; les signaux optiques utilisé dans les systèmes de télécommunications; certains signaux acoustiques et, en particulier, les impulsions produites par le système glottale; les signaux électriques modulés en position d’impulsions; une séquence d’événements dans une file d’attente; les trains de potentiels neuronaux dans le système neuronal. Ce paradigme de transmission est différent des communications continues traditionnelles et la compréhension des communications impulsives est donc essentielle. Afin d’affronter le problème des communications impulsives, le cadre de la recherche doit inclure les aspects suivants : la statistique d’interférence qui suit directement la structure des signaux impulsifs; l’interaction du signal impulsif avec le milieu physique; la possibilité pour les communications impulsives de coder l’information dans la structure temporelle. Cette thèse adresse une partie des questions précédentes et trace des lignes indicatives pour de futures recherches. En particulier, nous avons étudié: un système d'accès multiple où les utilisateurs adoptent des signaux avec étalement de spectre par saut temporel (time-hopping spread spectrum) pour communiquer vers un récepteur commun; un système avec un préfiltre à l'émetteur, et plus précisément un transmit matched filter, également connu comme time reversal dans la littérature de systèmes à bande ultra large; un modèle d'interférence pour des signaux impulsifs. / A communication is impulsive whenever the information-bearing signal is burst-like in time. Examples of the impulsive concept are: impulse-radio signals, that is, wireless signals occurring within short intervals of time; optical signals conveyed by photons; speech signals represented by sound pressure variations; pulse-position modulated electrical signals; a sequence of arrival/departure events in a queue; neural spike trains in the brain. Understanding impulsive communications requires to identify what is peculiar to this transmission paradigm, that is, different from traditional continuous communications.In order to address the problem of understanding impulsive vs. non-impulsive communications, the framework of investigation must include the following aspects: the different interference statistics directly following from the impulsive signal structure; the different interaction of the impulsive signal with the physical medium; the actual possibility for impulsive communications of coding information into the time structure, relaxing the implicit assumption made in continuous transmissions that time is a mere support. This thesis partially addresses a few of the above issues, and draws future lines of investigation. In particular, we studied: multiple access channels where each user adopts time-hopping spread-spectrum; systems using a specific prefilter at the transmitter side, namely the transmit matched filter (also known as time reversal), particularly suited for ultrawide bandwidhts; the distribution function of interference for impulsive systems in several different settings.