Digital Divide Across the European Union

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação

Digital Divide Across the European Union

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação

O que é o interface? Da entificação á identificação do interface enquanto complexo mediador

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em Ciências da Comunicação

A Terra como Interface: o paradigma do Mapa para o Século XXI

Trabalho de Projecto de Mestrado em Ciências de Comunicação Variante Novos Media e Práticas Web

Gesture based interface for image annotation

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Informática pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Prevalência do consumo do álcool em dois Centros de Saúde da Praia e num centro numa zona rural, Picos - Ilha de Santiago

RESUMO: Conhecer a prevalência e perfil de consumo das populações revela-se como elementos importantes para o estabelecimento de Planos e Programas de intervenção na atenção aos problemas relacionados com o consumo do álcool. Este estudo transversal numa amostra de utentes dos cuidados primários de saúde teve por objectivo conhecer a prevalência do consumo do álcool em dois centros de saúde numa zona urbana, (Achada de Santo António e Achadinha) na capital do país e um centro de saúde numa zona rural (Picos), no interior da ilha de Santiago. O instrumento utilizado para avaliar os consumos de médio e alto risco do álcool foi o ASSIST. Foram entrevistados 302 utentes nos 3 centros de saúde. Os resultados mostraram uma prevalência ao longo da vida de 86,4% e nos últimos 3 meses de 62,3%. Mostrou que os homens tinham consumo superior às mulheres no centro de saúde de Achadinha (p value= 0.002 ) e Picos (p value=0.003). Em Achada de Santo António a diferença entre homens e mulheres não se mostrou estatisticamente significativa (p value= 0.397). Os resultados mostraram também nos dois centros associação significativa entre consumo de risco de tabaco e consumo de risco do álcool (p value=0.000 e 0.003) o que não se verificou em ASA (p value= 0.962). As variáveis idade, ocupação profissional, nível de escolaridade, não mostraram associação significativa ao consumo de risco do álcool mas mostraram associação significativa ao consumo do álcool nos últimos 3 meses. Mas o consumo do álcool nos últimos 3 meses não mostrou associação significativa ao consumo do tabaco nos últimos 3 meses. Espera-se que os resultados possam subsidiar a política de luta contra o álcool, no sentido de implementar acções que possam prevenir os danos à saúde e outras consequências resultantes do consumo abusivo do álcool. --------- ABSTRACT: To determine the prevalence and consumption profile of populations revealed as important elements for establishing plans and intervention programs in attention to problems related to alcohol consumption. This cross-sectional study on a sample of users of primary health care was aimed to determine the prevalence of alcohol consumption in two health centers in an urban area, (Achada de Santo António and Achadinha) in the capital and a health center in a rural area (Picos), in the island of Santiago’s contryside. The instrument used to assess the intake of medium and high risk alcohol was the ASSIST. We interviewed 302 users in three health centers. The results showed lifetime prevalence of 86.4% and in the last 3 months of 62.3%. It showed that men were superior to women in consumption in both health centers of Achadinha (p value=0.002) and Picos (p value=0.000). In Achada de Santo António, the difference between men and women was not statistically significant (p value = 0397). The results also showed the two centers had a significant association between risk of tobacco consumption and risk consumption of alcohol (p value = 0.000 and 0.003) which was not found in ASA (p value = 0.962). There was no association between the variables (age, professional occupation, and educational level) and risk of alcohol consumption, but they showed a significant association with alcohol consumption in the last 3 months. On the other hand, the consumption of alcohol in the last three months showed no significant association with the consumption of tobacco in the last 3 months. It is hoped that the results may support the policy against alcohol, may implement actions that can prevent damage to the health and other consequences resulting from alcohol abuse.

Projeto de um altifalante digital

Devido ao crescente desenvolvimento das nanotecnologias, estando associadas a melhoria da eficiência energética assim como mais processamento de dados e a redução dos custos, esta dissertação possibilita todo o enquadramento com sistemas modernos ao nível do áudio digital. Tendo como base esta perspetiva, esta dissertação apresenta um sistema de áudio completo desde a fonte do sinal digital no PC até ao sinal analógico no altifalante. O sistema é constituído pelos seguintes módulos: a interface do utilizador no PC, o Processador Digital de Sinais (DSP), o amplificador digital e os altifalantes. O sistema é baseado na amplificação de classe D controlada por um modulador sigma delta (ΣΔM) digital. São abordadas as técnicas utilizadas e os cuidados a ter em conta em cada módulo, tendo como principal objetivo uma boa qualidade de áudio. Diferentes arquiteturas ΣΔM são primeiramente analisadas por simulações para validar a estabilidade e a funcionalidade, seguidamente são implementadas ao nível físico no protótipo para qualificar algumas medições elétricas e testes acústicos básicos. Depois de selecionados os ΣΔM mais promissores, o sistema foi avaliado pela análise de alguns testes elétricos de alto nível assim como gravações do sinal de áudio em um ambiente de estúdio controlado. Os resultados acústicos são comparados com um sistema de estúdio com reconhecimento no mercado. As medições finais do protótipo revelaram valores do rendimento de até 72%, a SNR na saída do amplificador digital de 73 dB através da leitura com o Audio Precision ATS-2, com uma THD de -75 dB e uma gama dinâmica (DR) de 75 dB. A tensão de alimentação pode ir dos 5 aos 12 Volt, utilizando uma metodologia H-bridge na saída do amplificador, e podendo ser aplicada uma carga mínima de 4 Ohm. O sistema desenvolvido demonstra-se promissor e possibilita melhorias através de otimização de cada elemento em particular, desde adicionar capacidades ao DSP através de novo firmware, ou melhorar a potência do amplificador digital consoante os requisitos da aplicação.

Control system for actuation and sensing in digital microfluidics devices

Digital Microfluidics (DMF) is a second generation technique, derived from the conventional microfluidics that instead of using continuous liquid fluxes, it uses only individual droplets driven by external electric signals. In this thesis a new DMF control/sensing system for visualization, droplet control (movement, dispensing, merging and splitting) and real time impedance measurement have been developed. The software for the proposed system was implemented in MATLAB with a graphical user interface. An Arduino was used as control board and dedicated circuits for voltage switching and contacts were designed and implemented in printed circuit boards. A high resolution camera was integrated for visualization. In our new approach, the DMF chips are driven by a dual-tone signal where the sum of two independent ac signals (one for droplet operations and the other for impedance sensing) is applied to the electrodes, and afterwards independently evaluated by a lock-in amplifier. With this new approach we were able to choose the appropriated amplitudes and frequencies for the different proposes (actuation and sensing). The measurements made were used to evaluate the real time droplet impedance enabling the knowledge of its position and velocity. This new approach opens new possibilities for impedance sensing and feedback control in DMF devices.

Land cover mapping analysis and urban growth modeling using remote sensing techniques

The rapid growth of big cities has been noticed since 1950s when the majority of world population turned to live in urban areas rather than villages, seeking better job opportunities and higher quality of services and lifestyle circumstances. This demographic transition from rural to urban is expected to have a continuous increase. Governments, especially in less developed countries, are going to face more challenges in different sectors, raising the essence of understanding the spatial pattern of the growth for an effective urban planning. The study aimed to detect, analyse and model the urban growth in Greater Cairo Region (GCR) as one of the fast growing mega cities in the world using remote sensing data. Knowing the current and estimated urbanization situation in GCR will help decision makers in Egypt to adjust their plans and develop new ones. These plans should focus on resources reallocation to overcome the problems arising in the future and to achieve a sustainable development of urban areas, especially after the high percentage of illegal settlements which took place in the last decades. The study focused on a period of 30 years; from 1984 to 2014, and the major transitions to urban were modelled to predict the future scenarios in 2025. Three satellite images of different time stamps (1984, 2003 and 2014) were classified using Support Vector Machines (SVM) classifier, then the land cover changes were detected by applying a high level mapping technique. Later the results were analyzed for higher accurate estimations of the urban growth in the future in 2025 using Land Change Modeler (LCM) embedded in IDRISI software. Moreover, the spatial and temporal urban growth patterns were analyzed using statistical metrics developed in FRAGSTATS software. The study resulted in an overall classification accuracy of 96%, 97.3% and 96.3% for 1984, 2003 and 2014’s map, respectively. Between 1984 and 2003, 19 179 hectares of vegetation and 21 417 hectares of desert changed to urban, while from 2003 to 2014, the transitions to urban from both land cover classes were found to be 16 486 and 31 045 hectares, respectively. The model results indicated that 14% of the vegetation and 4% of the desert in 2014 will turn into urban in 2025, representing 16 512 and 24 687 hectares, respectively.

Historical trajectories of currently shrinking Portuguese cities: A typology of urban shrinkage

Cities develop according to different patterns, undergoing population growth during some periods and decline (shrinkage) during others. Theories attempting to understand these behaviours include: 1) shrinkage is a natural process in the life cycle of a city, alternating with periods of growth, or 2) shrinkage is an extreme event that places cities into a continuous decline process with no return to population growth. We use retrospective data over a period of 130 years to study 25 Portuguese cities currently facing population decline, and show that both theories coexist in time and space. Five types of shrinking city are revealed: “Persistent Early Shrinkage” due to exodus fromthe rural periphery, “Metropolitan Shrinkage” due to the challenges of urban sprawl, “Recent Shrinkage” in de-industrialisation hotspots, “Cyclic Shrinkage” occurring in political transformation cores, and “Mild Shrinkage” due to life-style disamenity. As diversity of city population trajectories appears to be the norm in both Portugal and other Western European countries, the incorporation of this range into the management of urban transitions is recommended in order to reinforce city resilience.