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Ambiente para especificação de aplicações multimídia com suporte de qualidade de serviço
(Universidade Federal de São Carlos, 2004-08-23) Thereza, Wesley Barbosa; Zorzo, Sérgio Donizetti; https://lattes.cnpq.br/2523715806470871; https://lattes.cnpq.br/5509610744649925
This work describes an environment for specification of distributed multimedia applications with demanded Quality of Service (QoS) detailing. The description of the application is made in a hierarchic way, in the user, application and resource level, adding the demanded QoS parameters and the adaptation rules to be applied for the Quality of Service monitoring/ (re)negotiation. These rules and QoS parameters will be responsible for the activation of the system adaptation to guarantee its execution in compliance with the Quality of Service negotiated in the specification. After the specification phase of the distributed multimedia system, the environment generates the documentation in a specification language of system with QoS detailing and its adaptation/ (re)negotiation forms. This documentation feeds NIST Net emulator, allowing that the results can be analyzed by the verification of the multimedia system behavior and the emulated system.
Framework para implementação de serviços transmissores de vídeos voltados a PCS e dispositivos móveis, perceptivo à mudança contextual de localização
(Universidade Federal de São Carlos, 2004-08-23) Jardim, Fernando de Moraes; Trevelin, Luis Carlos; https://lattes.cnpq.br/5082419783043736
With the progress of the technology in data transmission area and the fact of computers be present more and more in several equipments, like PDAs (Personal Digital Systems), mobile telephones, cars, refrigerators, etc, it becomes necessary to establish a standart communication protocol among these several computers. The work presented in this monograph has as objective to define a necessary infrastructure to implementations of videos transmission services for mobile devices (PDAs and mobile telephones) with transparent change of location context. This context change represents the change of physical atmosphere of the proposed system user. The idea is that the user continues to watch a video (in a mobile device) when he leaves the place where he was watching it. A framework was modeled and implemented to detect change of physical atmosphere destined to videos transmission services directed to mobile devices. High degree of mobility and transparency is characteristic of Ubiquitous Computation (Computation new moment - Weiser). For a theoretical basement was carried through a research on the concepts related with Ubiquitous Computation, mobile devices and video transmissions. This work was developed in the Network and Distributed Systems Laboratory of São Carlos Federal University - UFSCar.
Estudos eletroquímicos das ligas biocompatíveis Ti-50Zr (at.%) e Ti-13Nb-13Zr (m/m)
(Universidade Federal de São Carlos, 2004-08-23) Oliveira, Nilson Tadeu Camarinho de; Biaggio, Sonia Regina; https://lattes.cnpq.br/0418215244233120
Studies on the anodic growth of the oxides that passivate the biocompatible alloys Ti-50Zr (at.%) and Ti-13Nb-13Zr (m/m), on the electrochemical/electrical parameters and the morphology, composition and structure of these oxides were carried out in this work. The oxides were grown by both the potentiodynamic and the galvanostatic routes, in different electrolytes at room temperature; their electrochemical stability was investigated in electrolytes that simulate the physiological medium. Based on the analyses carried out, it was concluded that the Ti-13Nb-13Zr alloy presented better protection against corrosion than the Ti-50Zr alloy and that the heat treatment of the alloy did not significantly influence the analysed electrochemical parameters. It was also shown that the pre-passivation of these metals in an inert electrolyte confers the oxides greater stability when exposed to chloride-containing media. The studies by electrochemical impedance spectroscopy indicated that the oxide films of both alloys present an electrical response of the R(RQ) type and that the resistance of the anodic oxide films increases with their thickness. Finally, based on results obtained by photocurrent spectroscopy (PCS), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD), it was verified that the anodic oxides grown on the alloys are formed by oxides of all the alloying elements, but with an enrichment in Ti in the oxide external layers.