Spanning trees with generalized degree constraints arising in the design of wireless networks

In this paper we describe a minimum spanning tree problem with generalized degree constraints which arises in the design of wireless networks. The signal strength on the receiver side of a wireless link decreases with the distance between transmitter and receiver. In order to work properly, the interference on the receiving part of the link must be under a given threshold. In order to guarantee this constraint, for each node we impose a degree constraint that depends on the ”length” of the links adjacent to the corresponding node, more precisely, nodes adjacent to long links must have a smaller degree and vice-versa. The problem is complicated by considering different signal strengths for each link. Increasing the strength in a link increases the cost of the link. However, it also reduces the maximum allowed degree on its end nodes. We create two models using adequate sets of variables, one may be considered an extended version of the other, and relate, from a theoretical perspective, the corresponding linear programming relaxations.FCT - POCTI-ISFL-1-152FCT - PTDC/EIA/64772/200

Water consumption monitoring system for public bathing facilities

The European Commission has been developing efforts resulting in directives and programs to stimulate water saving. The lack of information about water usage in public bathing facilities is an obstacle to achieve an adequate management. This work proposes a monitoring system able to observe individual water consumption in public bathing facilities. Gathered information will be used to characterize user behaviour, or even to drive changes in their attitudes.info:eu-repo/semantics/publishedVersio

Understanding the media sphere’s extensions: Testing knowledge by a quiz

The evaluation of knowledges regarding the media sphere is a growing activity, despite little consensus about how to do it. Notwithstanding these uncertainties, surveys are regularly used. This article presents the main outcomes of a quiz about the media. The game was played by 48 youngsters and adults. This experience sought to explore what people recognize in the media sphere and how can a game help in the task of assessing it. The analysis suggests that positive answers were mostly found among visual-based questions, in contrast to the ones related to sounds. This research also suggests the existence of “universal symbols”, recognizable by (almost) everyone. As a research method, the quiz was helpful to foster engagement, particularly when it became a one-o-one challenge

Broms : gestão uniforme de um parque computacional multi-plataforma

O crescimento dos parques de máquinas pessoais levanta consideráveis problemas de administração, contrastando com o que o ocorre com recursos centralizados. Nenhuma das soluções existentes para o efeito apresenta um compromisso aceitável entre a liberdade de configuração que se espera de uma máquina pessoal e o controlo eficiente dos recursos resultante de uma gestão centralizada. Neste contexto propõe se uma solução deste dilema através da coordenação de um sistema de boot remoto avançado com um conjunto de serviços de rede. A aplicação deste sistema à gestão e manutenção de laboratórios pedagógicos demonstrou que se pode assim criar um ambiente de ensino muito mais fiável e flexível do que o tradicional

O ESTUDO DA CULTURA ORGANIZACIONAL: O CASO DE UM CÂMPUS UNIVERSITÁRIO DA REGIÃO FRONTEIRA NOROESTE DO ESTADO DO RIO GRANDE DO SUL

Uma Universidade, por função inerente a ela mesmo e em decorrência de suas prerrogativas, pode promover o surgimento de forças estratégicas em todas as áreas, tornando-se por si mesmo a grande agência propulsora de crescimento e de desenvolvimento de uma comunidade, município e, até mesmo de uma região. Neste sentido, o presente estudo foi realizado num câmpus universitário de uma universidade regional multicampi com o objetivo de entender a percepção a partir de uma amostra de funcionários em relação a cultura organizacional. Para o levantamento de dados, o instrumento utilizado foi um questionário com perguntas abertas, aplicado através do método de contato direto aos colaboradores do câmpus, sendo que para a análise e interpretação de dados utilizou-se o método análise de conteúdo. O estudo foi realizado segundo a percepção de seus funcionários, enfocando os aspectos relacionados ao ambiente de trabalho, cultura organizacional, equipe de trabalho e elementos de motivação para o trabalho. Os resultados mostram que há um ambiente de trabalho propício a pratica do coleguismo e a presença de uma cultura sólida com preservação dos valores institucionais. Também se constata que há contentamento por parte dos funcionários em realizar atividades que satisfaçam suas necessidades pessoais

Conocer las extensiones de la esfera de los medios: Testeando conocimientos a partir de un quiz

A avaliação dos conhecimentos sobre os média é uma atividade em crescimento, mesmo havendo poucos consensos sobre o que medir e como o fazer. Os questionários são, contudo, comummente usados. Neste artigo problematizam-se os principais resultados de um quiz sobre o mundo dos média, no qual participaram 48 jogadores. Esta experiência permitiu constatar indícios de (re)conhecimentos sobre os média, testando o jogo enquanto instrumento de investigação. Os resultados sugerem que as questões envolvendo imagens foram mais facilmente reconhecidas, sobretudo se comparadas com as perguntas que usavam sons. É também possível falar de símbolos “universais” e de conteúdos cuja similitude de formas originou respostas aproximadas. O quiz e a competição com outrem revelaram-se particularmente úteis na promoção do empenho dos respondentes.The evaluation of knowledges regarding the media sphere is a growing activity, despite little consensus about how to do it. Notwithstanding these uncertainties, surveys are regularly used. This article presents the main outcomes of a quiz about the media. The game was played by 48 youngsters and adults. This experience sought to explore what people recognize in the media sphere and how can a game help in the task of assessing it. The analysis suggests that positive answers were mostly found among visual-based questions, in contrast to the ones related to sounds. This research also suggests the existence of “universal symbols”, recognizable by (almost) everyone. As a research method, the quiz was helpful to foster engagement, particularly when it became a one-o-one challenge.La evaluación de los conocimientos sobre los medios es una actividad en crecimiento, aunque haya pocos consensos sobre qué medir y cómo hacerlo. Los cuestionarios se utilizan comúnmente. En este artículo se cuestionan los principales resultados de un concurso sobre el mundo de los medios, en el que participaron 48 jugadores. Esta experiencia permitió constatar indicios de (re) conocimientos sobre los medios, probando el juego como instrumento de investigación. Los resultados sugieren que las cuestiones relacionadas con las imágenes fueron más fácilmente reconocidas, sobre todo si se comparan con las preguntas que usaban sonidos. Es también posible hablar de símbolos "universales" y de contenidos cuya similitud de formas originó respuestas aproximadas. El concurso y la competencia con otros se revelaron particularmente útiles en la promoción del compromiso de los encuestados.info:eu-repo/semantics/publishedVersio

Evaluation of the potential of biomass to energy in Portugal : conclusions from the CONVERTE project

ABSTRACT: The main objective of the Portuguese project "CONVERTE-Biomass Potential for Energy" is to support the transition to a low-carbon economy, identifying biomass typologies in mainland Portugal, namely agri-forest waste, energy crops and microalgae. Therefore, the aim was to design and construct a georeferenced (mapping) database for mainland Portugal, to identify land availability for the implementation of energy crops and microalgae cultures, and to locate agricultural and forestry production areas (including their residues) with potential for sustainable exploitation for energy. The ArcGIS software was used as a Geographic Information System (GIS) tool, introducing the data corresponding to the type of soil, water needs and edaphoclimatic conditions in shapefile and raster data type, to assess the areas for the implantation of the biomass of interest. After analysing the data of interest in each map in ArcGIS, the intersection of all maps is presented, suggesting adequate areas and predicting biomass productions for the implementation of each culture in mainland Portugal. Under the conditions of the study, cardoon (72 kha, 1085 kt), paulownia (81 kha, 26 kt) and microalgae (29 kha, 1616 kt) presented the greater viability to be exploited as biomass to energy in degraded and marginal soils.info:eu-repo/semantics/publishedVersio

Consumer perception of the circular economy concept applied to the food domain: an exploratory approach

Every year, agri-food industries in industrialised countries produce approximately 1.3 billion tonnes of food loss and waste. The adoption of a circular economy policy has received special attention by the agri-food industries, allowing for the creation and development of new food products made of by-products that would otherwise be wasted or used for secondary applications. The present work, of an exploratory nature, aims to assess how consumers conceptualise the circular economy in order to identify consumer recognition of the use of by-products from the food industry to upcycle food products and to evaluate attitudes towards the circular economy. To this end, a mixedmethodology was applied to 340 participants. The first part was qualitative and used free word association to evaluate consumers’ conceptualisation of the circular economy and use of by-products as foods. Data were analysed by grouping the responses into exclusive and exhaustive categories and a correspondence analysis was also performed to originate perceptual maps. Additionally, a questionnaire was designed to evaluate major concepts and attitudes correlated with the circular economy. Data were reduced by principal component analysis (PCA) and participants grouped through clustering. Results showed that consumers understand circular economy as related mainly into Sustainability, Economy, and Circularity dimensions. Participants had great difficulty identifying the by-products used as foods or as food ingredients. From the quantitative data, four groups were identified based on the associations to the six principal components originated by the PCA. However, the results highlighted a very low association with all clusters of the Food Valorisation dimension within the concept of the circular economy, and also a lack of a clear understanding of consumers’ attitudes towards food products from the circular economy. Greater promotion and dissemination by the competent entities aimed at the general public may contribute towards greater integration, participation and acceptance of the circular economy concept for the upscaling of food by-products.info:eu-repo/semantics/publishedVersio