Digital Tv Systems
Mostrando 13-24 de 48 artigos, teses e dissertações.
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13. Um modelo arquitetural para captura e uso de informações de contexto em sistemas de anotações de vídeo / An architectural model to capture and use context information in video annotation systems
Diversos pesquisadores vêm investigando métodos e técnicas para tornar possível às pessoas anotarem vídeos de modo transparente. A anotação pode ser realizada com a fala, com o uso de tinta digital ou algum outro meio que possa ser capturado enquanto a pessoa assiste ao vídeo. Tais anotações podem ser compartilhadas com outras pessoas, que podem e
Publicado em: 2010
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14. Códigos LDPC quaternários aplicados à técnica de transmissão OFDM / Quaternary LDPC codes applied to OFDM transmission technique
This dissertation addresses the study of error correcting codes based on sparse non-binary matrices. The LDPC (Low Density Parity Check) codes constitute a efficient family of codes generated by sparse parity check matrices and it is considered as one of the classes of codes that presents the best performance in digital communications systems. LDPC codes ove
Publicado em: 2010
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15. Desempenho de codigo turbo quaternario em sistemas de multiplexação por divisão de frequencias ortogonais / Performance of quaternary turbo codes in orthogonal frequency division multiplex systems
This study evaluates the performance of quaternary turbo codes, with generator matrix G = [7, 5] for the constituent convolutional codes and s-random interleaving , in an OFDM transmission system. This performance is measured in terms of bit error rate versus energy per bit to unilateral noise power spectral density ratio. The results obtained are analyzed c
Publicado em: 2010
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16. Using eye tracking to evaluate the user experience upon interactive television applications. / Uso de rastreamento do olhar na avaliação da experiência do tele-usuário de aplicações de TV interativa.
The introduction of digital terrestrial TV in Brazil allows users of free TV, the main source of information and entertainment in the country, to have access to services offered by Interactive TV (TVi). These users, who constitute a large and heterogeneous population, composed of individuals of varying degrees of education, age and knowledge of computers, wi
Publicado em: 2009
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17. DIRCE - Design da Interação e Levantamento de Requisitos com Foco na Comunicação e Exploração de Ideias: Experiências de Uso Aplicadas em Sistemas de Criação de Conteúdo para a Televisão Digital / DIRCE - Design da interação e levantamento de requisitos com foco na comunicação e exploração de ideias : experiências de uso aplicadas em sistemas de criação de conteúdo para a televisão digital
This paper aims to present a methodology for helping professionals to focus on aspects of interaction from the early stages of the process of developing an innovative system. The methodology guides the application of techniques aimed at the requirements gathering and design of the interaction of such a system, considering the experiences of users and the mod
Publicado em: 2009
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18. Impacto da utilização de tecnicas de lifting explorando diferença entre ferramentas interpretada e compilada na velocidade computacional da codificação wavelet de imagens estaticas / Impact of using lifting techniques to explore the differences between interpreted and compiled tools in the computational speed of wavelet static image coding
The field of analysis and compression of images has been received special attention of the scientific community because of including in the main systems of digital TV, satellite communications and mobile communications. In this context, the Discrete Transform Wavelet (TWD) arise how a powerful tool and its many advantages allowed your insertion in important
Publicado em: 2009
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19. Estimativa do número de estações de rádio base para a implantação do WIMAX no Distrito Federal
During the past years, the video, voice and data services available in the fixed communications networks have been requested by users in mobility. This fact has motivated the development of technologies that allow traffic of a lot of information in cellular telephone networks. WiMAX e UMTS are technologies that can help the traffic flow. The WiMAX, known as
Publicado em: 2009
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20. FAVIHC Framework de Avaliação da Interação Humano-Computador / FAVIHC - Framework de AValiação da Interação Humano Computador
In order to implement a software development process following certain quality constraints, which must be observed by the involved professionals (namely developers, customers, users and designers), it is paramount that those professionals interact. Such an interaction is necessary in order to design, build and evaluate the software. Moreover, the evaluation
Publicado em: 2009
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21. A modular platform for tests with interactivity in the Brazilian digital TV. / Uma plataforma modular para testes com interatividade na TV digital brasileira.
We have watched the transition from analog TV to digital TV around the world in the last two decades, with the establishment of international systems, as ATSC, DVB and ISDB. At the end of 2007, the Brazilian Digital Television System (SBTVD) was released for commercial purposes in São Paulo City. SBTVD brings significant innovations, from which we emphasize
Publicado em: 2008
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22. Arquimedia: uma proposta de arquitetura de software para terminais de acesso à TV digital interativa. / Arquimedia: a set-top-box software architecture proposal to interactive digital TV.
The terrestrial digital television systems have been established and expanded by the worldwide. It is expected that 1.4 billion analog TV sets will be replaced by set-topboxes and digital receivers TV sets, also known as access terminals. This fact shows the relevance of these devices that receive and decode the digital signals. Given the diversity of the ha
Publicado em: 2008
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23. Intercalamento temporal por transformada de Fourier: um novo método robusto para transmissão de sinais de TV Digital. / Fourier transform based time interleaving.
This work introduces a new transform-based time interleaving algorithm: FTI-OFDM (Fourier Transform Interleaved OFDM), in which binary information is spread over several symbols, both in time and frequency domains. This process, designed to be included in digital modulation systems, is computationally efficient when used in conjunction with OFDM modulation.
Publicado em: 2008
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24. H-N2N : uma arquitetura hierárquica escalável para ambientes de realidade mista de grande porte
In this work, we propose a solution to solve the scalability problem found in collaborative, virtual and mixed reality environments of large scale, that use the hierarchical client-server model. Basically, we use a hierarchy of servers. When the capacity of a server is reached, a new server is created as a sun of the first one, and the system load is distrib
Publicado em: 2008