967 resultados para Digital TV


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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 distributed between them (father and sun). We propose efficient tools and techniques for solving problems inherent to client-server model, as the definition of clusters of users, distribution and redistribution of users through the servers, and some mixing and filtering operations, that are necessary to reduce flow between servers. The new model was tested, in simulation, emulation and in interactive applications that were implemented. The results of these experimentations show enhancements in the traditional, previous models indicating the usability of the proposed in problems of all-to-all communications. This is the case of interactive games and other applications devoted to Internet (including multi-user environments) and interactive applications of the Brazilian Digital Television System, to be developed by the research group. Keywords: large scale virtual environments, interactive digital tv, distributed

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Deaf people have serious difficulties to access information. The support for sign languages is rarely addressed in Information and Communication Technologies (ICT). Furthermore, in scientific literature, there is a lack of works related to machine translation for sign languages in real-time and open-domain scenarios, such as TV. To minimize these problems, in this work, we propose a solution for automatic generation of Brazilian Sign Language (LIBRAS) video tracks into captioned digital multimedia contents. These tracks are generated from a real-time machine translation strategy, which performs the translation from a Brazilian Portuguese subtitle stream (e.g., a movie subtitle or a closed caption stream). Furthermore, the proposed solution is open-domain and has a set of mechanisms that exploit human computation to generate and maintain their linguistic constructions. Some implementations of the proposed solution were developed for digital TV, Web and Digital Cinema platforms, and a set of experiments with deaf users was developed to evaluate the main aspects of the solution. The results showed that the proposed solution is efficient and able to generate and embed LIBRAS tracks in real-time scenarios and is a practical and feasible alternative to reduce barriers of deaf to access information, especially when human interpreters are not available

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The telecommunications industry has experienced recent changes, due to increasing quest for access to digital services for data, video and multimedia, especially using the mobile phone networks. Recently in Brazil, mobile operators are upgrading their networks to third generations systems (3G) providing to users broadband services such as video conferencing, Internet, digital TV and more. These new networks that provides mobility and high data rates has allowed the development of new market concepts. Currently the market is focused on the expansion of WiMAX technology, which is gaining increasingly the market for mobile voice and data. In Brazil, the commercial interest for this technology appears to the first award of licenses in the 3.5 GHz band. In February 2003 ANATEL held the 003/2002/SPV-ANATEL bidding, where it offered blocks of frequencies in the range of 3.5 GHz. The enterprises who purchased blocks of frequency were: Embratel, Brazil Telecom (Vant), Grupo Sinos, Neovia and WKVE, each one with operations spread in some regions of Brazil. For this and other wireless communications systems are implemented effectively, many efforts have been invested in attempts to developing simulation methods for coverage prediction that is close to reality as much as possible so that they may become believers and indispensable tools to design wireless communications systems. In this work wasm developed a genetic algorithm (GA's) that is able to optimize the models for predicting propagation loss at applicable frequency range of 3.5 GHz, thus enabling an estimate of the signal closer to reality to avoid significant errors in planning and implementation a system of wireless communication

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Model-oriented strategies have been used to facilitate products customization in the software products lines (SPL) context and to generate the source code of these derived products through variability management. Most of these strategies use an UML (Unified Modeling Language)-based model specification. Despite its wide application, the UML-based model specification has some limitations such as the fact that it is essentially graphic, presents deficiencies regarding the precise description of the system architecture semantic representation, and generates a large model, thus hampering the visualization and comprehension of the system elements. In contrast, architecture description languages (ADLs) provide graphic and textual support for the structural representation of architectural elements, their constraints and interactions. This thesis introduces ArchSPL-MDD, a model-driven strategy in which models are specified and configured by using the LightPL-ACME ADL. Such strategy is associated to a generic process with systematic activities that enable to automatically generate customized source code from the product model. ArchSPLMDD strategy integrates aspect-oriented software development (AOSD), modeldriven development (MDD) and SPL, thus enabling the explicit modeling as well as the modularization of variabilities and crosscutting concerns. The process is instantiated by the ArchSPL-MDD tool, which supports the specification of domain models (the focus of the development) in LightPL-ACME. The ArchSPL-MDD uses the Ginga Digital TV middleware as case study. In order to evaluate the efficiency, applicability, expressiveness, and complexity of the ArchSPL-MDD strategy, a controlled experiment was carried out in order to evaluate and compare the ArchSPL-MDD tool with the GingaForAll tool, which instantiates the process that is part of the GingaForAll UML-based strategy. Both tools were used for configuring the products of Ginga SPL and generating the product source code

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The process for choosing the best components to build systems has become increasingly complex. It becomes more critical if it was need to consider many combinations of components in the context of an architectural configuration. These circumstances occur, mainly, when we have to deal with systems involving critical requirements, such as the timing constraints in distributed multimedia systems, the network bandwidth in mobile applications or even the reliability in real-time systems. This work proposes a process of dynamic selection of architectural configurations based on non-functional requirements criteria of the system, which can be used during a dynamic adaptation. This proposal uses the MAUT theory (Multi-Attribute Utility Theory) for decision making from a finite set of possibilities, which involve multiple criteria to be analyzed. Additionally, it was proposed a metamodel which can be used to describe the application s requirements in terms of the non-functional requirements criteria and their expected values, to express them in order to make the selection of the desired configuration. As a proof of concept, it was implemented a module that performs the dynamic choice of configurations, the MoSAC. This module was implemented using a component-based development approach (CBD), performing a selection of architectural configurations based on the proposed selection process involving multiple criteria. This work also presents a case study where an application was developed in the context of Digital TV to evaluate the time spent on the module to return a valid configuration to be used in a middleware with autoadaptative features, the middleware AdaptTV

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In this work we present the architecture and implementation of MyPersonal-EPG, a personal EPG with support to recommendations, built on top of the Ginga middleware, that fulfill the following requirements: (i) to allow users to build their own personal programming grids, based on programming guides from several broadcasters; (ii) to offer a mechanism to tune the desired channels on the moment the selected programs are about to begin; (iii) to allow users to select the desired programs categories; (iv) to offer programs recommendations, in both synchronous and asynchronous way, based on the categories previously selected by users; (v) to allow users to modify the current configuration options; (vi) to allow the creation of several users accounts, so that each user can store its own information. The application‟s usability test is also presented and its results are discussed and analyzed

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Many challenges have been imposed on the middleware to support applications for digital TV because of the heterogeneity and resource constraints of execution platforms. In this scenario, the middleware must be highly configurable so that it can be customized to meet the requirements of applications and underlying platforms. This work aims to present the GingaForAll, a software product line developed for the Ginga - the middleware of the Brazilian Digital TV (SBTVD). GingaForAll adds the concepts of software product line, aspect orientation and model-driven development to allow: (i) the specification of the common characteristics and variables of the middleware, (ii) the modularization of crosscutting concerns - both mandatory and concepts variables - through aspects, (iii) the expression of concepts as a set of models that increase the level of abstraction and enables management of various software artifacts in terms of configurable models. This work presents the architecture of the software product line that implements such a tool and architecture that supports automatic customization of middleware. The work also presents a tool that implements the process of generating products GingaForAll

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This article presents considerations about viability on reutilize existing web based e-Learning systems on Interactive Digital TV environment according to Digital TV standard adopted in Brazil. Considering the popularity of Moodle system in academic and corporative area, such system was chosen as a foundation for a survey into its properties to create a specification of an Application Programming Interface (API) for convergence to t-Learning characteristics that demands efforts in interface design area due the fact that computer and TV concepts are totally different. This work aims to present studies concerning user interface design during two stages: survey and detail of functionalities from an e-Learning system and how to adapt them for the Interactive TV regarding usability context and Information Architecture concepts.

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Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

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Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

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Esta Tese propõe o desenvolvimento de uma estratégia de planejamento que combina: caracterização de carga de uma aplicação típica de TV Digital, extração de vetor peso por meio de redes de crença e tomada de decisão multicriterio a partir da aplicação de métodos analíticos (TOPSIS e ELECTRE III), para fornecer suporte a decisão junto a provedores de serviços, objetivando-se permitir optar-se por uma tecnologia para canal de retorno (ADSL2+, PLC, WiMAX e 3G), considerando a carga típica de um cenário de TV Digital interativo, padrão ISDB-T. A estratégia proposta apresenta cinco etapas, sendo estas: definição dos canais de retorno e das métricas de desempenho, realização de medições das tecnologias de acesso em cenários reais, simulação dos dados em ambientes simulados, aplicação de técnicas de correlação de dados para geração do vetor peso e aplicação de métodos analíticos de tomada de decisão para escolha da melhor tecnologia a ser implantada em determinado cenário. Como resultado principal se obteve um modelo genérico e flexível que foi validado através de um estudo de caso que ordenou a preferência das tecnologias avaliadas.

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This article aims to describe the proposed development of an emulator application for digital TV that operates on a local computer network, to have it as a testing environment for students and researchers. The emulator application is presented as a useful tool to reduce validation costs of applications developed for digital TV.

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Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

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Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC