Made available in DSpace on 2014-12-17T15:48:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-02 / Multimedia systems must incorporate middleware concepts in order to abstract hardware and operational systems issues. Applications in those systems may be executed in different kinds of platforms, and their components need to communicate with each other. In this context, it is needed the definition of specific communication mechanisms for the transmission of information flow. This work presents a interconnection component model for distributed multimedia environments, and its implementation details. The model offers specific communication mechanisms for transmission of information flow between software components considering the Cosmos framework requirements in order to support component dynamic reconfiguration / Sistemas multim?dia devem incorporar conceitos de middleware de forma a abstrair especificidades de hardware e sistemas operacionais. Aplica??es nestes sistemas podem ser executadas em diferentes tipos de plataformas, e os componentes destes sistemas precisam interagir uns com os outros. Neste contexto, faz-se necess?rio a defini??o de mecanismos de comunica??o espec?ficos para a transmiss?o de fluxos de informa??o. Este trabalho apresenta um modelo para a interconex?o de componentes em ambientes multim?dia, e sua arquitetura de implementa??o. O modelo oferece mecanismos de comunica??o espec?ficos para a transmiss?o de fluxos de informa??o entre componentes de software atendendo aos requisitos do framework Cosmos de maneira a suportar a reconfigura??o din?mica de componentes

Made available in DSpace on 2014-12-17T15:48:13Z (GMT). No. of bitstreams: 1 CarlosES.pdf: 1065336 bytes, checksum: c1840ccdd384fc7c59635d8e173e484f (MD5) Previous issue date: 2007-02-05 / Multimedia systems must incorporate middleware concepts in order to abstract hardware and operational systems issues. Applications in those systems may be executed in different kinds of platforms, and their components need to communicate with each other. In this context, it is needed the definition of specific communication mechanisms for the transmission of information flow. This work presents a interconnection component model for distributed multimedia environments, and its implementation details. The model offers specific communication mechanisms for transmission of information flow between software components considering the Cosmos framework requirements in order to support component dynamic reconfiguration / Sistemas multim?dia devem incorporar conceitos de middleware de forma a abstrair especificidades de hardware e sistemas operacionais. Aplica??es nestes sistemas podem ser executadas em diferentes tipos de plataformas, e os componentes destes sistemas precisam interagir uns com os outros. Neste contexto, faz-se necess?rio a defini??o de mecanismos de comunica??o espec?ficos para a transmiss?o de fluxos de informa??o. Este trabalho apresenta um modelo para a interconex?o de componentes em ambientes multim?dia, e sua arquitetura de implementa??o. O modelo oferece mecanismos de comunica??o espec?ficos para a transmiss?o de fluxos de informa??o entre componentes de software atendendo aos requisitos do framework Cosmos de maneira a suportar a reconfigura??o din?mica de componentes

Made available in DSpace on 2014-12-17T15:47:53Z (GMT). No. of bitstreams: 1 FelipeAPP_DISSERT.pdf: 2094888 bytes, checksum: 2f662bc70058d8584f0a23ab28517f43 (MD5) Previous issue date: 2011-01-19 / Distributed multimedia systems have highly variable characteristics, resulting in new requirements while new technologies become available or in the need for adequacy in accordance with the amount of available resources. So, these systems should provide support for dynamic adaptations in order to adjust their structures and behaviors at runtime. This paper presents an approach to adaptation model-based and proposes a reflective and component-based framework for construction and support of self-adaptive distributed multimedia systems, providing many facilities for the development and evolution of such systems, such as dynamic adaptation. The propose is to keep one or more models to represent the system at runtime, so some external entity can perform an analysis of these models by identifying problems and trying to solve them. These models integrate the reflective meta-level, acting as a system self-representation. The framework defines a meta-model for description of self-adaptive distributed multimedia applications, which can represent components and their relationships, policies for QoS specification and adaptation actions. Additionally, this paper proposes an ADL and architecture for model-based adaptation. As a case study, this paper presents some scenarios to demonstrate the application of the framework in practice, with and without the use of ADL, as well as check some characteristics related to dynamic adaptation / Sistemas multim?dia distribu?dos possuem caracter?sticas bastante vari?veis, podendo implicar em novos requisitos ? medida que novas tecnologias s?o disponibilizadas ou na necessidade de adequa??o de acordo com a quantidade de recursos dispon?veis. Dessa forma, tais aplica??es devem ser capazes de realizar ajustes e adapta??es din?micas, permitindo alterar sua estrutura e comportamento. Com o objetivo de prover capacidades de autoadapta??o nesses sistemas, este trabalho apresenta uma abordagem de adapta??o baseada em modelos. ? proposto um framework reflexivo e baseado em componentes para a constru??o e suporte de sistemas multim?dia distribu?dos autoadaptativos, fornecendo v?rias facilidades para o desenvolvimento e evolu??o de tais sistemas, como adapta??o din?mica. A proposta do framework ? manter um ou mais modelos de representa??o do sistema em tempo de execu??o, de modo que alguma entidade externa possa realizar uma an?lise desses modelos identificando problemas e tentando resolv?-los. Esses modelos integram o metan?vel reflexivo das aplica??es atuando como uma autorrepresenta??o do sistema. Para isso, o framework define um metamodelo para a descri??o de aplica??es multim?dia distribu?das autoadaptativas, o qual ? capaz de representar componentes e seus relacionamentos, pol?ticas para especifica??o de QoS e a??es de adapta??o. Adicionalmente, ? proposta uma ADL e uma arquitetura para adapta??o baseada em modelos. Como estudo de caso o trabalho apresenta alguns cen?rios buscando exemplificar o uso do framework na pr?tica, com e sem o uso da ADL, bem como verificar algumas caracter?sticas relacionadas ? adapta??o din?mica

Made available in DSpace on 2014-12-17T14:55:32Z (GMT). No. of bitstreams: 1 WeldsonQL_capa_ate_pag12.pdf: 7162119 bytes, checksum: 5c9eb475de4851ecfa9f44218d55308a (MD5) Previous issue date: 2004-12-10 / In the two last decades of the past century, following the consolidation of the Internet as the world-wide computer network, applications generating more robust data flows started to appear. The increasing use of videoconferencing stimulated the creation of a new form of point-to-multipoint transmission called IP Multicast. All companies working in the area of software and the hardware development for network videoconferencing have adjusted their products as well as developed new solutionsfor the use of multicast. However the configuration of such different solutions is not easy done, moreover when changes in the operational system are also requirede. Besides, the existing free tools have limited functions, and the current comercial solutions are heavily dependent on specific platforms. Along with the maturity of IP Multicast technology and with its inclusion in all the current operational systems, the object-oriented programming languages had developed classes able to handle multicast traflic. So, with the help of Java APIs for network, data bases and hipertext, it became possible to the develop an Integrated Environment able to handle multicast traffic, which is the major objective of this work. This document describes the implementation of the above mentioned environment, which provides many functions to use and manage multicast traffic, functions which existed only in a limited way and just in few tools, normally the comercial ones. This environment is useful to different kinds of users, so that it can be used by common users, who want to join multimedia Internet sessions, as well as more advenced users such engineers and network administrators who may need to monitor and handle multicast traffic / Nas duas ?ltimas d?cadas do s?culo passado, com a consolida??o da Internet como rede mundial de computadores, aplica??es de fluxos mais robustos come?aram a surgir. A crescente uso de videoconfer?ncias impulsionou a cria??o de uma forma de transmiss?o ponto-multiponto chamada Multicast IP. Todas as empresas que desenvolviam software e hardware para videoconfer?ncia adequaram seus produtos e criaram novas solu??es para o uso do fluxo multicast. Entretanto, a configura??o das diversas solu??es n?o ? trivial e, normalmente, altera??es no sistema operacional precisam ser realizadas. Al?m disso, ferramentas gratuitas apresentam funcionalidades limitadas, e as solu??es propriet?rias encontradas na atualidade s?o muito dependentes de plataformas espec?ficas. Com o amadurecimento da tecnologia Multicast IP e com sua inclus?o em todos os sistemas operacionais atuais, as linguagens de programa??o desenvolveram classes capazes de manipular tr?fego multicast. Com as APIs Java para redes, banco de dados e p?ginas Web, tornou-se poss?vel a cria??o de um Ambiente Integrado capaz de manipular tr?fego multicast, que se constitui na proposta central deste trabalho. Esse documento descreve ent?o a implementa??o deste ambiente que agrega diversas funcionalidades para utiliza??o e ger?ncia de tr?fego multicast, funcionalidades at? ent?o presentes de forma limitada em poucas e distintas ferramentas comummente propriet?rias. O ambiente se adequa a diferentes perfis de usu?rio, no sentido de que pode ser usado por leigos em Engenharia de Redes, que desejem apenas participar de sess?es de multim?dia na Internet, como tamb?m por especialistas e administradores de rede que desejem monitorar e manipular o tr?fego multicast