Browsing by Issue Date, starting with "2018-09"
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- Retargeting UHD 4k Video for SmartphonesPublication . Kumar, Rohit; Navarro, António; Assunção, Pedro; Ferreira, LinoThis paper evaluates a new video-retargeting algorithm jointly with two others previously published in the literature. Four Ultra High Definition (UHD) 4K resolution video sequences were used for subjective assessment. Subjective testing results show that the proposed algorithm yields the best performance when UHD 4K video is retargeted to 1920 × 1080 resolution. The main application of these retargeting algorithms is to increase the quality of experience (QoE) provided to consumers when playing UHD videos on small screen devices like smartphones.
- Effects of strength and conditioning programs in strength and dynamic balance in older adultsPublication . Salvador, Rogério; Coelho, Luís; Matos, Rui; Cruz, João R.; Rebelo-Goncalves, Ricardo; Amaro, NunoTo independently accomplish their daily routines with no need of assistance, older adults require an optimal physical fitness. In fact, this lack of physical fitness may reduce older individuals’ quality of life, leading to dependence on personal daily assistance or even to becoming significantly more prone to fatal falls [1]. Prevention through physical activity programs, are used to slow down and delay these aging effects, by improving individuals’ agility, flexibility and body improved functionality. Most of these programs take place in in-water environment due to age limiting factors such as high-risk osteoporosis, reduced mobility, higher risk of fracture from falls, arthrosis and spinal disorders among other.
- Afonso Lopes VieiraPublication . Nobre, CristinaEm 1932, ocorre um dos episódios mais negros da vida de Afonso Lopes Vieira, enquanto conferencista convidado da viagem diplomática a África, entre maio e julho, com repercussões interessantes numa produção literária que foge um pouco ao cânone habitual. Lopes Vieira pronuncia as conferências planeadas em Angola — "A Fé e o Império" (em 28 de junho) e "Camões, o poeta de além mar" (em 1 de julho) — mas um grave diferendo com Henrique Galvão, então diretor das Feiras de Amostras de Luanda e de Lourenço Marques e representante do ministro das Colónias, impede-o de prosseguir viagem até Moçambique.
- Análise matemática e realidade aumentada: um estudo no ensino superior em PortugalPublication . Cardoso, Teresa; Coimbra, Teresa; Mateus, ArturNeste texto, começamos por definir Realidade Aumentada (RA), enquadrando-a nas tecnologias tridimensionais, referindo a sua importância e atualidade. Depois, num breve estado da arte, apresentamos um mapeamento, a partir de estudos que focam a RA em contextos educacionais, nomeadamente no ensino superior e no domínio da matemática. Posteriormente, descrevemos parte do estudo desenvolvido no âmbito do trabalho de doutoramento “As Tecnologias Tridimensionais como contributo para a aprendizagem da Matemática no Ensino Superior”, que teve como objetivo principal contribuir para uma compreensão mais profunda de como as tecnologias tridimensionais podem potenciar o ensino e a aprendizagem da Matemática, no contexto nacional do ensino superior, em particular na área das engenharias. Da análise dos nossos dados e resultados, foi possível concluir que os desafios que se colocam hoje ao nível dos métodos de ensino, da aquisição e consequente consolidação do conhecimento podem ser em parte (cor)respondidos com a aplicação de tecnologias disponíveis, como a RA, que permitam uma compreensão mais completa dos conteúdos, levando à endogeneização de conhecimento e também à internalização de competências com bases mais sólidas.
- Positive effects of a health promotion program in sedentary elderly with type 2 diabetesPublication . Coelho, Luís; Amaro, Nuno; Cruz, João R.; Salvador, Rogério; Rosa, Paulino; Rebelo-Goncalves, Ricardo; Matos, RuiTo independently accomplish their daily routines with no need of assistance, older adults require an optimal physical fitness. In fact, this lack of physical fitness may reduce older individuals’ quality of life, leading to dependence on personal daily assistance or even to becoming significantly more prone to fatal falls [1]. Prevention through physical activity programs, are used to slow down and delay these aging effects, by improving individuals’ agility, flexibility and body improved functionality. Most of these programs take place in in-water environment due to age limiting factors such as high-risk osteoporosis, reduced mobility, higher risk of fracture from falls, arthrosis and spinal disorders among other.
- Interrater reliability of the injury reporting of the injury surveillance system used in international athletics championshipsPublication . Edouard, Pascal; Junge, Astrid; Kiss-Polauf, Marianna; Ramirez, Christophe; Sousa, Monica; Timpka, Toomas; Branco, PedroAbstract Objectives The quality of epidemiological injury data depends on the reliability of reporting to an injury surveillance system. Ascertaining whether all physicians/physiotherapists report the same information for the same injury case is of major interest to determine data validity. The aim of this study was therefore to analyse the data collection reliability through the analysis of the interrater reliability. Design Cross-sectional survey. Methods During the 2016 European Athletics Advanced Athletics Medicine Course in Amsterdam, all national medical teams were asked to complete seven virtual case reports on a standardised injury report form using the same definitions and classifications of injuries as the international athletics championships injury surveillance protocol. The completeness of data and the Fleiss’ kappa coefficients for the inter-rater reliability were calculated for: sex, age, event, circumstance, location, type, assumed cause and estimated time-loss. Results Forty-one team physicians and physiotherapists of national medical teams participated in the study (response rate 89.1%). Data completeness was 96.9%. The Fleiss’ kappa coefficients were: almost perfect for sex (k = 1), injury location (k = 0.991), event (k = 0.953), circumstance (k = 0.942), and age (k = 0.870), moderate for type (k = 0.507), fair for assumed cause (k = 0.394), and poor for estimated time-loss (k = 0.155). Conclusions The injury surveillance system used during international athletics championships provided reliable data for “sex”, “location”, “event”, “circumstance”, and “age”. More caution should be taken for “assumed cause” and “type”, and even more for “estimated time-loss”. This injury surveillance system displays satisfactory data quality (reliable data and high data completeness), and thus, can be recommended as tool to collect epidemiology information on injuries during international athletics championships.
- Light Field Image Coding using High Order Prediction TrainingPublication . Monteiro, Ricardo J. S.; Nunes, Paulo J. L.; Faria, Sergio; M. M. Rodrigues, NunoThis paper proposes a new method for light field image coding relying on a high order prediction mode based on a training algorithm. The proposed approach is applied as an Intra prediction method based on a two-stage block-wise high order prediction model that supports geometric transformations up to eight degrees of freedom. Light field images comprise an array of micro-images that are related by complex perspective deformations that cannot be efficiently compensated by state-of-the-art image coding techniques, which are usually based on low order translational prediction models. The proposed prediction mode is able to exploit the non-local spatial redundancy introduced by light field image structure and a training algorithm is applied on different micro-images that are available in the reference region aiming at reducing the amount of signaling data sent to the receiver. The training direction that generates the most efficient geometric transformation for the current block is determined in the encoder side and signaled to the decoder using an index. The decoder is therefore able to repeat the high order prediction training to generate the desired geometric transformation. Experimental results show bitrate savings up to 12.57% and 50.03% relatively to a light field image coding solution based on low order prediction without training and HEVC, respectively.
- Measurements and Modelling of Spatial Diversity using 2D TransmitarrayPublication . Reis, Joao R.; Hammoudeh, Akram; Copner, Nigel; Caldeirinha, RafaelThis paper disseminates the results of the first experimental trials on Spatial Diversity (SD) with beamsteering capabilities by the means of 2D transmitarray and thus reduced RF chains. The SD arrangement is composed of a dual antenna configuration in which beamsteering is activated by using electronically reconfigurable transmitarray (eRT) in front of the two single directive antennas. The experimental radiation patterns obtained at 5.2 GHz proves the usefulness of the concept.
- Water efficiency analysis in the classroom building and hydraulics laboratory of the Faculty of Engineering, Physical Sciences And Mathematic – Central University of EcuadorPublication . Portilla, Carlos Andres Valenzuela; Gomes, Ricardo de Jesus; Afonso, Armando B. Silva; Tobar, Freddy MuñozEcuador, located in the middle of the world, is one of the smallest countries in South America with the largest number of surface and underground freshwater resources. The global impact that affects the world reserves of this natural resource, also affects the countries of the region due to an accelerated population growth, climate change, the obsoleting of technology and the shortage of habits about the need to reduce excessive consumption and waste of drinking water. The highest rate of drinking water consumption among the countries of South America is from Ecuador, with more than 237 liters/(inhabitant.day). This alarming figure is one of the reasons why it is important to reduce drinking water consumption in non-residential buildings without affecting the comfort of users. The main objective of this work is to analyze the water efficiency of university buildings in Quito through the application of the calculation model suggested by the Portuguese Association for Quality in Building Services Installations (ANQIP). Different strategies and techniques are applied to fulfill this objective, among them, the architectural and hydro-sanitary characterization of the buildings, the evaluation of each sanitary device and its water efficiency, as well as the determination of volumetric flows in the facilities of the buildings that form part of the case study. The gradual shortage of drinking water generates the need to find alternative sources for the supply of this resource. The design of a rainwater harvesting system becomes the integral solution proposed to supply water for non-potable uses, to reduce consumptions of potable water, to reduce billing costs and to transform buildings into hydraulically sustainable projects. It is concluded that rainwater harvesting systems provide important volumes of water for non-drinking purposes in buildings such as university establishments.
- Eficiencia hídrica en edificios no residenciales de tipo colectivos (hoteles)Publication . Andrade, Dario Javier Bermudez; Gomes, Ricardo de Jesus; Afonso, Armando B. Silva; Gutiérrez, JaimeEl agua es uno de los recursos más importantes para la vida, el problema de escasez de agua afecta directamente a toda la población mundial, es un deber de los seres humanos garantizar la disponibilidad a largo plazo del líquido vital. En los edificios se genera un gran impacto sobre el recurso agua, donde se observan principalmente elevados dotaciones de agua para el consumo humano a lo largo del ciclo de vida del edificio, a las fallas cometidas en la fase de diseño, al uso y probables desperfectos de aparatos hidráulicos que además presentan elevados consumos, es decir, que no son hidráulicamente eficientes. El concepto de eficiencia hídrica en edificios nos direcciona a investigar y presentar soluciones o recomendaciones que permitan ahorrar agua en los edificios independientemente del uso que se le proporcione, de tal manera se puede atenuar las consecuencias de escasez que este recurso pueda generar por el acelerado crecimiento poblacional y económico a nivel mundial. La auditoría hídrica de los edificios permite identificar las ineficiencias en los sistemas prediales y así proponer alternativas para el uso eficiente del agua durante la fase de utilización. Con el análisis de las alternativas técnicas y económicas se plantea determinar el costo de inversión inicial que debe realizarse para la implementación de las alternativas planteadas y el tiempo de retorno de mencionada inversión. En el sector hotelero existen varias interrogantes sobre el análisis y determinación de padrones de consumo debido a que no es posible generalizar todos los casos y deben ser analizados de manera independiente.