3019253 documents found, page 218 of 301926
Editorial
Vaz, Francisco; Oliveira, José LuisNeste número iniciamos a publicação de artigos convidados, como é o caso do artigo da autoria do Prof. Valery Sklyarov, professor catedrático visitante do nosso departamento. (...)
Sistema de videotelefonia para Windows suportado em comunicações RDIS
Firmeza, João Paulo N.; Bouça, Valter José G.; Ramos, Fernando M. S.; Santos, Osvaldo A.A Video Phone application for the MS-Windows platform is a package of software that allow us to talk to another person while viewing his image. This is one of the new applications that can be done by using the facilities of ISDN (Integrated Services Digital Network). Using ISDN and Vídeo Capture cards currently available for PC 'Vídeo Telephony for Windows' gained form.; Um sistema de video telefonia para a pla...
Síntese de circuitos conformes com o standard Boundary Scan
Antunes, Ana; Marzouki, Meryem; Ferrari, AntónioThis paper presents a tool that allows the inclusion of the Boundary Scan test logic in a VHDL description of a given integrated circuit.; Este artigo apresenta uma ferramenta que permite a inclusão de facilidades de teste ao nível da descrição VHDL de um circuito integrado. A lógica de teste incluida respeita o standard Boundary Scan.
Geração de vectores de teste por emparelhamento
Dias, Fernando Morgado; Touati, Mohamed Hedi; Marzouki, Meryem; Ferrari, AntónioThis paper presents a method to generate test vectors for an electronic board composed of modules from which the structural description it’s not known. The only information available is the set of test vectors, their coverage on the primary inputs and outputs of each module provided by the manufacturer and the composition of the board. This method provides test vectors to test the board from its primary inputs ...
Estudo das características de distorção não linear de intermodulação de desmodu...
Carvalho, Nuno Borges; Madureira, Raquel Castro; Pedro, José CarlosThe nonlinear distortion of a PLL frequency discriminator is addressed using the Volterra Series approach. The analysis, made entirely in the frequency domain, allows distortion calculations for periodic and nonperiodic sets of discrete excitation frequencies (harmonic and intermodulation distortion up to 3rd order) and random inputs. It also includes, simultaneously, the two major sources of distortion in a PL...
Controlador de memória dinâmica para o μP68030
Carvalho, N. Borges; Silva, R. Vieira; Cruz, A. NunesApresenta-se o projecto dum controlador, que implementa a interface do μP68030 a uma memória dinâmica. A memória permite o acesso de bytes, words e longwords, suportando ainda um modo de acesso rápido (‘Nibble’). Para aumentar a confiabilidade (‘reliability’), a interface inclui ainda um circuito de detecção e correcção de erros.
User interface for a dentist office management tool
De Francesco, Silvia; Barreto, Carlos Loff; Santos, Beatriz Sousa; Rafael, José AlbertoIn this paper the prototype of a user interface for a dentist office management tool is described. Accordingly to the rules of the human-computer software interface design, as a first step, the study of the needs and the profile of thepossible users was performed. Using the results of this study a prototype was developed, consisting basically on three tightly linked environments: the Agenda, the Patients’ data ...
Monitorização de pressão arterial
Fernandes, João; Martins, João; Oliveira, José Manuel; Tomé, Ana MariaIn this paper, we describe an arterial pressure monitoring system. The system, based on personal computer, adquires, processes and display the signals and results envolved on particular medical procedure. The system requirements were specified with the cooperation of the medical staff. The system’s software was developed using object programing techniques.; Neste artigo é apresentado e descrito um sistema ...
The simulation of systolic array implementation schemes for Hopfield neural nets
Mazurkiewicz, JacekThe paper describes the simulation of systolic array schemes for Hopield nets. The implementation presented is based on completely digital circuits. Input data is passed through the neurones in a time shared basis, weights are stored in digital shift registers and no separate threshold detectors are used. The simulation was realised using EASE/VHDL ver. 2.2 and V-System/Windows ver. 4.; Este artigo descreve a s...
Implementação de um sistema de codificação RELP para fins didáticos
Neto, Carlos; Silva, Carlos; Vaz, FranciscoIn this work we implemented a RELP speech coder. This type of coder is well known and presents medium complexity. It is useful to study because it includes different signal processing techniques that are used in more modern and efficient speech coders. Special attention was given to the user’s interface enabling a simple way to change the coding parameters and an easy display of the signals in different stages ...