In the modern society, almost everyone has a smartphone. These devices tend to almost always use WiFi-networking. For the device to identify nearby WiFi access points it has to send out WiFi probing broadcasts. Nearby access points respond to these broadcasts in order to let the device know that they are within reach. This technique is called active scanning. This paper aims to answer if it is possible to use the signal strength of these broadcasts to localize the device transmitting them. We are interested in the possibility of creating this kind of system and the accuracy that it would be able to provide. This is a quantitative study where we produce our results based on experiments, measurements and observations. The experiments are set in a large square shaped area. A sensor was placed at each corner of the area that the smartphone will be tracked within. The smartphone will be sending WiFi probing broadcasts that will be monitored and measured by the sensors. The strength of the broadcast signal will be converted into the relative distance between the devices position and the sensors. These four distances, collected from each of the sensors, will further be converted into a position within the area by using trilateration. To measure the accuracy of the system, the true position of the device will be compared against the calculated position from the system using only the signal strength. Further, a deviation in the distance between the two locations will be calculated. The experiments resulted in a positioning system that was able to estimate positions within an 80 x 80m area. Fourteen location positions were taken which resulted in a mean deviation of 16.6 meters from the true location and a root mean squared error of 19.5 meters. We concluded that more readings within the same position gave a significant increase in accuracy, to the expense of time. Using single measurements would be more practical, but would not produce reliable positions. Keywords: WiFi, Probe Broadcast, Local Positioning System, Trilateration, RSSI.

O objetivo desta dissertação é pensar a transmissão direta via televisão a partir do que aqui se denomina tempo morto, períodos menos concentrados de fluxo do evento transmitido. Em toda teletransmissão, há embates entre dois fluxos informativos distintos – o do evento e o da televisão –, que são resolvidos segundo processos (moldurações) que expressam figuras (molduras) propriamente televisivas. Ao circunscrever a observação aos tempos mortos, pode-se compreender com maior clareza que estratégias televisivas são empregadas nesta transposição. O objeto de estudo é o futebol televisivo, a partir da observação das onze últimas finais de Copas do Mundo (1970-2010). Nelas, são identificadas algumas figuras de tempo morto, como imagens de personas e figuras de manipulação temporal, analisadas sincrônica e diacronicamente. / The aim of this work is to think direct broadcast television from what is called dead time herein, periods less concentrated of flow of the event broadcast. Throughout teletransmission there is clashes between two different information flows - the event and the television - which are resolved in accordance with processes (moldurações) expressing television figures (molduras). When observing the dead time, one can understand more clearly what strategies are employed in this transposition of an event to the television. The object of study is football, based on the observation of the eleven last World Cups final games (1970-2010).

As trajetórias e as atuações profissionais de duas personalidades emblemáticas do campo artístico-intelectual das Américas no século XX – Alan Lomax e Radamés Gnattali – apresentam-se nesta investigação como elementos centrais para a aproximação entre os projetos político-culturais implementados no âmbito das relações Brasil-EUA no período entre 1939 e 1945. O agenciamento desses atores foi determinante na criação de modelos de performatização musical utilizados em programas radiofônicos de conteúdo "folclórico", que, segundo se infere, contribuíram para as transformações políticas e culturais por que passaram ambos os países durante a 2ª Guerra Mundial. Do ponto de vista teórico-metodológico, a hipótese que justifica uma aproximação entre os projetos é que tanto as técnicas de arranjo utilizadas por Gnattali para os programas feitos em parceria com Almirante na Rádio Nacional do Brasil (1941-1945) como as performances musicais conduzidas por Lomax e seus convidados nos programas da CBS nos EUA (1939-1941) podem ser interpretadas como processos de agenciamento entre os produtores, os grupos sociais representados nos programas, os modelos ideológicos defendidos por intelectuais especializados no estudo do folclore e os interesses políticos dos regimes. Esses núcleos de poder, portanto, se relacionariam de forma heterogênea em relação à identidade nacional nos diferentes contextos em que foram inseridos. Por meio de exemplos de programas da série Wellspring of music – escrita e produzida por Alan Lomax para o projeto American School of the Air – e da série Aquarelas do Brasil – produzida por Radamés Gnattali, Almirante e José Mauro e patrocinada pela empresa norte-americana Pan-American World Airlines –, busca-se examinar as estratégias utilizadas para a criação dos modelos de performance musical responsáveis pelos processos de comunicação simbólica operados pelos programas, que teriam contribuído tanto no Brasil como nos EUA para a construção de identidades nacionais utilizadas nos contextos regionais e pan-americanos. / The study of the trajectories and professional activities of two emblematic personalities on the artistic and intellectual scene of the Americas in the 20th century – Alan Lomax and Radames Gnattali – present themselves in this investigation as central elements in the analysis between the cultural projects and policies implemented under Brazil-US relations in the period between 1939-1945. To this end, this research seeks to examine, through a theoretical and methodological perspective, how the these actors’ agency were instrumental in creating different performance models related with "folk" content used in radio shows that intended to contribute to the political and cultural transformations faced by both countries during the Second World War. The hypothesis for this relationship between the trajectories is that both Gnattali’s arrangement techniques used in the programs in partnership with Almirante at the National Radio of Brazil (1941-1945), and the idealized musical performances used by Lomax and his partners for the series produced by CBS in the USA (1939-1941), could be perceived as mediation processes between the social groups represented on the radio shows, the ideological models advocated by intellectuals linked to folklore, and the political interests that took part in national and international schemes. These centers of power, therefore, would deal heterogeneously in relation to their identities in the contexts in which they were performed. Using examples of two programs – one from the series "Wellspring of Music," written and produced by Lomax that was part of the project American School of the Air, and one from the program "Aquarelas do Brasil" [Watercolors of Brazil] produced by Radamés Gnattali and Almirante and sponsored by Pan American World Airlines—the research will also highlight the strategies used in the musical performances developed by those radio producers as a mediation field in relation to the semiotic process, as sound material became important symbols of national identity used in national and Pan-American projects.

This report concerns the implementation of a simulation framework to evaluate an emerging peer-to-peer network topology scheme using 8-point hypercircles, entitled HyperCircle. This topology was proposed in order to alleviate some of the drawbacks of current P2P systems evolving in an uncontrolled manner, such as scalability issues, network overload and long search times. The framework is supposed to be used to evaluate the advantages of this new topology. The framework has been built on top of an existing simulator software solution, the selection of which was an important part of the development. Weighing different variables such as scalability and API usability, the selection fell on OverSim, an open-source discreet-event simulator based on OMNET++. After formalizing the protocol for easier implementation, as well as extending it for better performance, implementation followed using C++ with OverSim’s API and simulation library. Implemented as a module (alongside other stock modules providing their own protocols such as Chord and Kademlia), it can be used in OverSim to simulate a user-defined network using one of the simulation routine applications provided (or using a custom application written by the user). For the purposes of this thesis, the standard application KBRTestApp was used; an application sending test messages between randomly selected nodes, while adding and removing nodes at specific time intervals. The adding and removing of nodes can be configured with probability parameters. Tentative testing shows that this implementation of the HyperCircle protocol has a certain performance gain over the OverSim implementations of the Chord and Kademlia protocols, measurable in the time it takes a message to get from sender to recipient. Further testing is outside the scope of this thesis.

Em sistemas MIMO multiusuÃrio, o transmissor pode selecionar um subconjunto de antenas e/ou usuÃrios que tÃm bons canais para maximizar o rendimento do sistema usando vÃrios critÃrios de seleÃÃo. AlÃm disso, os prÃ-codificadores podem proporcionar dimensÃes livres de interferÃncia. O alinhamento de interferÃncia (IA) à baseado no conceito de prÃ-codificaÃÃo e oferece diferentes compromissos entre complexidade e desempenho. A idÃia bÃsica do Alinhamento InterferÃncia consiste em prÃ-codificar os sinais transmitidos de maneira que os mesmos sejam alinhados no receptor, em que eles constituem interferÃncia, enquanto que ao mesmo tempo os separa do sinal desejado. No entanto, a InformaÃÃo do Estado do Canal (CSI) tem sido uma preocupaÃÃo para os pesquisadores porque ela tem um impacto no desempenho de algoritmos de IA. Assim, nos propomos a analisar o desempenho da seleÃÃo de antena e diversidade multiusuÃrio em conjunto, a fim de permitir o IA oportunista usando vÃrios critÃrios com relaÃÃo à perturbaÃÃo da CSI. AnÃlises e simulaÃÃes verificam o comportamento do esquema proposto. / In multiuser MIMO systems, the transmitter can select a subset of antennas and/or users which have good channel conditions to maximize the system throughput using various selection criteria. Furthermore, precoding can provide free interference dimensions. The Interference Alignment (IA) is based on the concept of precoding and it offers different trade-offs between complexity and performance. The basic idea of Interference Alignment consists in precoding the transmitted signals such that they are aligned at the receiver where they constitute interference, while at the same time disjointed from the desired signal. However, the Channel State Information (CSI) has been a concern because it impacts the performance of IA algorithms. Hence, we propose to analyze the performance of antenna selection and multiuser diversity together in order to allow opportunistic IA using several criteria over the disturbance of CSI. Analyses and simulations verify the behavior of the proposed scheme.

Com a crescente transformação no campo tecnológico, o jornalista é imerso diariamente em novos desafios que mudam não somente a forma de pensamento, mas também o fazer da profissão. No radiojornalismo, esse percurso deve ser avaliado com cuidado. Primeiramente é importante desconstruir a ideia de ascensão e queda desse meio de comunicação a cada novidade que surge. A radiorreportagem pode ser vista como a mais importante das atividades do repórter de rádio. Esse deve ser o momento em que ele prepara para o ouvinte um material rico em sons ambientes para que ele seja facilmente transportado para a cena relatada. Porém, muitas mudanças ocorrem na sociedade contemporânea e transformam essa relação, sendo uma das principais o conceito de convergência das mídias que resignifica a compreensão da radiorreportagem e o papel do repórter de rádio. Doze entrevistados acadêmicos e profissionais foram ouvidos e teceram uma análise sobre os principais pontos de discussão ao redor desse tema: o conceito de radiorreportagem, a evolução dos aparatos técnicos, convergência das mídias e internet, a importância da linguagem radiofônica e o ensino de radiojornalismo nos bancos das universidades buscando auxiliar os profissionais da área de rádio quanto à prática, ao ensino e à pesquisa. / Following the never-ending changes in technological field, journalists are undergoing new challenges day after day, reshaping not only the ways of thinking, but the very nature of doing things in this profession as well. In broadcast journalism, this path must be considered with special care. At first, is paramount to unfold the idea of rise and fall of this media every time a new media appears. Broadcast journalism might be seen as the most important activity for radio journalists. Is just the time when he or she prepares for his or her audience a material carved with environmental sounds to place them into the described scene with ease. Nevertheless, a myriad of changes occur in modern day society and transform this relation, being the media convergence concept one of those major changes, unveiling a new meaning on the understanding of broadcast journalism and the role of radio journalists. Twelve scholars and professionals were interviewed, having the opportunity to analyze the main discussion topics on this subject: broadcast journalism concept, technical gear evolution, media and internet convergence, importance of radio-specific language and teaching of broadcast journalism in College chairs aiming to support radio professionals in regard to teaching and research.

As trajetórias e as atuações profissionais de duas personalidades emblemáticas do campo artístico-intelectual das Américas no século XX – Alan Lomax e Radamés Gnattali – apresentam-se nesta investigação como elementos centrais para a aproximação entre os projetos político-culturais implementados no âmbito das relações Brasil-EUA no período entre 1939 e 1945. O agenciamento desses atores foi determinante na criação de modelos de performatização musical utilizados em programas radiofônicos de conteúdo "folclórico", que, segundo se infere, contribuíram para as transformações políticas e culturais por que passaram ambos os países durante a 2ª Guerra Mundial. Do ponto de vista teórico-metodológico, a hipótese que justifica uma aproximação entre os projetos é que tanto as técnicas de arranjo utilizadas por Gnattali para os programas feitos em parceria com Almirante na Rádio Nacional do Brasil (1941-1945) como as performances musicais conduzidas por Lomax e seus convidados nos programas da CBS nos EUA (1939-1941) podem ser interpretadas como processos de agenciamento entre os produtores, os grupos sociais representados nos programas, os modelos ideológicos defendidos por intelectuais especializados no estudo do folclore e os interesses políticos dos regimes. Esses núcleos de poder, portanto, se relacionariam de forma heterogênea em relação à identidade nacional nos diferentes contextos em que foram inseridos. Por meio de exemplos de programas da série Wellspring of music – escrita e produzida por Alan Lomax para o projeto American School of the Air – e da série Aquarelas do Brasil – produzida por Radamés Gnattali, Almirante e José Mauro e patrocinada pela empresa norte-americana Pan-American World Airlines –, busca-se examinar as estratégias utilizadas para a criação dos modelos de performance musical responsáveis pelos processos de comunicação simbólica operados pelos programas, que teriam contribuído tanto no Brasil como nos EUA para a construção de identidades nacionais utilizadas nos contextos regionais e pan-americanos. / The study of the trajectories and professional activities of two emblematic personalities on the artistic and intellectual scene of the Americas in the 20th century – Alan Lomax and Radames Gnattali – present themselves in this investigation as central elements in the analysis between the cultural projects and policies implemented under Brazil-US relations in the period between 1939-1945. To this end, this research seeks to examine, through a theoretical and methodological perspective, how the these actors’ agency were instrumental in creating different performance models related with "folk" content used in radio shows that intended to contribute to the political and cultural transformations faced by both countries during the Second World War. The hypothesis for this relationship between the trajectories is that both Gnattali’s arrangement techniques used in the programs in partnership with Almirante at the National Radio of Brazil (1941-1945), and the idealized musical performances used by Lomax and his partners for the series produced by CBS in the USA (1939-1941), could be perceived as mediation processes between the social groups represented on the radio shows, the ideological models advocated by intellectuals linked to folklore, and the political interests that took part in national and international schemes. These centers of power, therefore, would deal heterogeneously in relation to their identities in the contexts in which they were performed. Using examples of two programs – one from the series "Wellspring of Music," written and produced by Lomax that was part of the project American School of the Air, and one from the program "Aquarelas do Brasil" [Watercolors of Brazil] produced by Radamés Gnattali and Almirante and sponsored by Pan American World Airlines—the research will also highlight the strategies used in the musical performances developed by those radio producers as a mediation field in relation to the semiotic process, as sound material became important symbols of national identity used in national and Pan-American projects.

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-03-08T18:24:55Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Natália Raposo FINAL.pdf: 1175211 bytes, checksum: 4d0a8d60bf67edc56e319ef04afafa5c (MD5) / Made available in DSpace on 2016-03-08T18:24:55Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Natália Raposo FINAL.pdf: 1175211 bytes, checksum: 4d0a8d60bf67edc56e319ef04afafa5c (MD5) Previous issue date: 2015-03-23 / FACEPE / Este estudo apresenta uma análise das representações de transtornos mentais construídas pela série Males da Alma, exibida no programa Fantástico e apresentada pelo médico oncologista Dráuzio Varella. Entendendo o jornalismo, em especial o televisivo, como um elemento que contribui para construir a realidade social, acredita-se que as representações que este constrói dos transtornos mentais podem influenciar na forma como o público os percebe e mesmo na experiência de estar doente. A fundamentação teórica deste trabalho se sustenta em discussões sobre os campos da comunicação, jornalismo e saúde; abordagens construtivistas do jornalismo, bem como nas teorias do enquadramento e das representações sociais. Para analisar o corpus, partiu-se do método de análise de imagens em movimento, desenvolvido por Diana Rose, a partir do qual se analisou as representações sociais dos transtornos mentais nas reportagens telejornalísticas, com base na teoria de Serge Moscovici, e considerando as dimensões de texto, imagem e som. Com um mapa representacional dos transtornos, foi possível perceber a enfermidade representada em um ciclo que se inicia com o sofrimento e termina na superação, passando, para isso, por fases como a luta e a medicação. Verificou-se que as reportagens reforçam o discurso de autoridade médica, pelo monopólio da fala do especialista e pela legitimidade que o capital científico de Dráuzio Varella confere a seu discurso. Ademais, verificou-se que embora as reportagens se estruturem a partir de histórias de pessoas doentes, o foco continua sendo a doença, reforçando o conflito maniqueísta do bem, a saúde, contra o mal, a doença. / This study examines the representations of mental disorders in the TV series Males da Alma (“Illnesses of the Soul”) hosted by the oncologist Dráuzio Varella, aired in the TV show Fantástico. Considering that journalism, especially the broadcast type, strongly contributes to the construction of social reality, those representations are believed to affect the way the TV show's viewers perceive and experience such mental disorders. This study's theoretical framework draws on the perspectives of Social Constructionism, Frame Analysis and Social Representations. It approaches the fields of Communication Studies, Journalism and Health. The analysis is based on the Method of Analysis of Moving Images, developed by Diana Rose, whereby were analyzed the social representations of the mental disorders in the TV reports. Considering the text, image and sound dimensions, this study also approached the conceptual contribution of Serge Moscovici. A representational map of the disorders made possible to notice the illness represented in a cycle that begins with suffering and ends with the patient overcoming it, going through stages of struggle and medicalization. The TV reports, although built up on real stories of ill people, were found to be reinforcing the medical authority speech. This whether through the monopoly of the specialist’s voice or through the legitimacy of the scientific capital of Dr. Dráuzio Varella granted to his speech. Moreover, it was found that although the reports are structured from stories of sick people, the focus of the reports still is the illness, thus reinforcing the Manichean conflict between the good - the health- and the evil - the illness.

Orientador: Renato da Rocha Lopes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia e de Computação / Made available in DSpace on 2018-08-14T18:25:14Z (GMT). No. of bitstreams: 1 Fernandes_FabioGabrielli_M.pdf: 950144 bytes, checksum: f268abbc8dd690c948f3054725c478ef (MD5) Previous issue date: 2009 / Resumo: Estratégias de comunicação multiusuário, aliadas ao uso de múltiplas antenas nos terminais, proporcionam ganhos, como aumento de taxas e robustez, se comparadas à abordagem ponto -a- ponto. No entanto, a obtenção de alguns destes ganhos exige conhecimento do canal no transmissor. Em geral, o transmissor possui apenas conhecimento parcial, impreciso, do canal, obtido através de realimentação feita pelos receptores. O foco do trabalho é a exploração do conhecimento parcial de canal no downlink de um sistema sem fio, com um transmissor central com múltiplas antenas e receptores com uma ou mais antenas cada. É proposto um método de realimentação de estado de canal que visa obter altas taxas de transmissão com o uso do menor número possível de bits. A informação é dividida em direção e qualidade do canal. A informação de direção consiste da quantização do canal na variedade de Grassmann. Como qualidade do canal, propomos o uso de um limitante inferior da relação sinal-interferência-mais-ruído de cada usuário, quando o método de zero-forcing beamforming é utilizado e canais quase-ortogonais são escolhidos. É derivado o limitante, bem como ajustes para incorporar informação que levam ao aumento da taxa de transmissão. Constata-se que o desempenho desta proposta é superior ao de técnicas anteriores em termos de taxa-soma do canal. / Abstract: Multiuser communication strategies, together with the use of multiple antennas, result in better performance when compared to the point-to-point approach. However, they are highly dependent on knowledge of channel state information at the transmitter, which in general requires that the receivers feed back the estimated channel. The focus of this work is the problem of partial channel state information at the transmitter in the downlink of a wireless system composed of a central transmitter with multiple antennas and several receivers with one or more antennas each. A feedback method is proposed, using zero-forcing beamforming, which aims to achieve high sum rates while using the least amount of feedback bits possible. The channel state information is divided in channel direction and channel quality information. The direction information consists of a quantized version of the direction of the channel vector, which can be seen as quantization in the Grassmann manifold. We propose the use of a lower bound on the signal-to-interference-plus-noise ratio of each user, which assumes the selection of near-orthogonal users. The lower bound is derived, as well as adjustments intended to add information available at the transmitter side that lead to an increase in the sum rates. Simulation results show that the proposed method outperforms similar techniques in terms of sum rate in most scenarios. / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Competition in many market-driven media systems in advanced industrial countries can sometimes compromise traditional public service broadcast values such as programming for diversity, citizenship, minority interests and national identity. This study investigates the presence and effects of commercial-logic in a state-owned broadcaster in a developing country: the Malawi Broadcasting Corporation. Using indepth interviews and analysis of records on finance and programme schedules, the study finds overwhelming indicators of the presence of commercial logic, not driven by competition, but a commitment to provide a public service under deteriorating financial conditions. Distinguishing between the impacts of advertising and sponsorship markets on media output, the study finds contradictory effects of commercialisation. Some effects confirm some of the adverse effects of commercialisation such as heavy sponsorinfluence on programme content, self-censorship among programme producers who avoid injuring sponsors and producers paying more attention to sponsored programmes at the expense ofthe quality of some non-sponsored public service programmes. However, effects are not always contrary to public service broadcasting but may Indeed reinforce such broadcasting. Commercialisation in some instances has led to the sustenance of a range of non-sponsored public service programmes including programmes to promote culture and civic rights. In general, this study highlights the need to focus on what is realistically possible within the dynamics of the Malawi Society as a precondition for a proactive and elaborate strategy for commercialisation ofthe country's public broadcaster.