Encontrados 34 documentos, a visualizar página 1 de 4
SIGEMO: Sistema de Gestão de Moldes
Rui Marques; Tiago Sousa; A. Manuel de Oliveira Duarte; Alexandre Sousa; Alexandre PauloThis paper presents the methods used for the development of a project that intends to contribute for the implementation of a logistic system of identification, management and flow control of materials (raw materials, products in assembly stage, tools and support machinery) for application in industrial environments. This work was the final project to obtain a degree in Electronics and Telecommunications Enginee...
Sistema Interactivo para a Inovação e Transferência Tecnológica
Carlos Guerra Martins; Jorge Manuel Pais V. Oliveira; A. Manuel de Oliveira Duarte; Ana Rita SantosThis article was made to present the Interactive System for the Innovation and Technological Transfer.It's main objective is to contribute for the developing of aninformation system whose characteristics are suitable for theacademic-scientific community requests and that encouragesthe transfer of the knowledge and cooperation between thescientific system (Universities, Institutes and TechnologicalCenters) and t...
Infrared Wireless Local Area Networks
Rui Jorge Morais Tomaz Valadas; A. Manuel de Oliveira Duarte; José Manuel Rego Lourenço BrázioThis thesis studies infrared wireless local area networks, considering simultuneously the physical link and medium access aspects. A general description of free-space infrared physical links is carried out, with the main purpose of characterising and comparing quasi-diffuse and diffuse cells (in quasi-diffuse cells the optical connection between stations is through a single reflector while in the diffuse cells ...
High Linearity Topologies for Wide Band Analog Optical Receivers
Paulo Henrique Grilo Domingues; A. Manuel de Oliveira Duarte; José Carlos Esteves Duarte PedroThe work to be presented was motivated by a contribution to the design of an optical receiver for use in an all-optical cable television distribution network, and evolves over the field of Linearization of amplifiers based on GaAs MESFET devices. (...)Keywords: amplifiers; linearization; intermodulation; distortion; cable televisionPh.D., 1996more info. http://opac.ua.pt/F/?func=find-b&find_code=S...
Optical Wireless Transmission Systems for Indoor Environments
Adriano Jorge Cardoso Moreira; A. Manuel de Oliveira Duarte; Rui Jorge Morais Tomaz ValadasThis thesis studies the performance of wireless in-house transmission systems using infrared optical signals. These studies focus in the physical layer of the transmission systems. (...)keywords: infrared; wireless communications;modulation; PPM; ambient noise; artificial light interference; frame format; IEEE 802.11Ph.D., 1998more info. http://opac.ua.pt/F/?func=find-b&find_code=SYS&REQUEST=0...
Wireless Indoor Infrared Communications: Modelling, Simulation and Optimisation...
Cipriano Rogério Alves Tavares Lomba; A. Manuel de Oliveira Duarte; Rui Jorge Morais Tomaz ValadasThis thesis studies the propagation of optical signals in indoor environments, aiming the development of high speed and high performance wireless infrared communication systems. Special attention is given to aspects of modelling, simulation and optimisation of the optical channel. An overview o f wireless indoor optical communication systems is presented. (...)keywords: infrared; wireless infrared communic...
SP-LD Control System: Architecture Overview, System Hardware and Software
António Jaime Ramos; A. Manuel de Oliveira DuarteThe aim of this project is to develop and implement a control system for an SP-LD. The system should control the pulsation frequency and the temperature of the device and present information on these and other parameters on a computer screen. (...)Keywords: SP-LD; control sytems; architecture; system software; system hardwareM.S., 1994 ; O objectivo deste projecto é desenvolver e implementar um sis...
Implementation of an Infrared Communications System using Microelectronics Tech...
Rui Luis Andrade Aguiar; A. Manuel de Oliveira Duarte; Dinis Magalhães dos SantosThis document presents the physical layer of a wireless infrared network, with special focus on the network controller. As wireless systems are usually used with portable units, power consumption and physical size are key issues. Large scale integration techniques are required in order to fulfill these restrictions. (...)Keywords: Wireless transmission systems; wireless LANS; infrared transmission; protoco...
Analysis of Simultaneous Transmission of Analogue and Digital Channels in a Opt...
Paulo Emanuel da Costa Pereira Afonso; A. Manuel de Oliveira Duarte; Paulo Henrique Grilo DominguesSubcarrier multiplexing systems for television and services delivery. Source function of intermodulation products. (...)Keywords: optical fiber; intermodulation noise; overmodulation; clipping; distortion; subcarrier multiplexing (SCM); linearity; televisionM.S., 1995more info. http://opac.ua.pt/F/?func=find-b&find_code=SYS&REQUEST=000073716 ; Sistemas de multiplexagem de subportadoras para d...
133 anos de história das comunicações em Portugal
Raquel Castro Madureira; A. Manuel de Oliveira Duarte; Raquel Matias da FonsecaThe communications are a key factor for the social and economical progress. The technologic development and the generalised use of the communication systems in the everyday life, increase the demand for broadband systems and high transmission technologies. In this scenario new market opportunities arise as well as new regulation challenges. This article presents an overview of the Communications Sector in Portu...
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