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Two-dimensional transmitarray beamsteering using stacked tunable metamaterials
Publication . Reis, João; Al-Daher, Zaid; Copner, Nigel; Hammoudeh, Akram; Caldeirinha, Rafael; Fernandes, Telmo
A new 2D-beamsteering antenna technique using an electronically controlled transmitarray is presented in this paper. When coupled to a conventional horn or an array patch antenna, the proposed transmitarray has the ability to steer the main lobe of the original antenna radiation pattern in both elevation and azimuth planes, with ranges up to 30° and 30°, respectively. The transmitarray is implemented using varactor-diode controlled unit-cells with bandpass filtering characteristics around 5.35GHz. Electromagnetic simulations are presented to prove the concept.
On the Evaluation of Software Maintainability Using Automatic Test Case Generation
Publication . Nogueira, Ana Filipa; Ribeiro, José C. B.; Zenha-Rela, Mário A.
The measurement of external software attributes and the analysis of how those attributes have evolved through the software's releases are challenging activities. This is particularly evident when we discuss the maintainability of Object-Oriented (OO) systems which, due to their specific characteristics, hide information that cannot be gathered through static analysis. As maintainability can be defined as the "speed and ease with which a program can be corrected or changed", we believe that test data are reflective of the changes performed during maintenance. Moreover, empirical observations allow to speculate about the relationships between maintainability and the behaviour of the software when executed by test cases (e.g., coverage values) and the test cases' characteristics (e.g., generation time). Our aim is to complement the state-of-the art by proposing a new approach for understanding and characterizing the maintainability of OO systems, which makes use of test data and of the information gathered from the tests' execution.
Imported Malaria in Portugal 2000–2009: A Role for Hospital Statistics for Better Estimates and Surveillance
Publication . Fonseca, Ana Glória; Dias, Sara S.; Baptista, João Luis; Torgal, Jorge
Background. Although eradicated in Portugal, malaria keeps taking its toll on travelers and migrants from endemic countries. Disease notification is mandatory but is compromised by underreporting. Methods. A retrospective study on malaria hospitalizations for 10 consecutive years (2000–2009) was conducted. Data on hospitalizations and notifications were obtained from Central Administration of Health System and Health Protection Agency, respectively. For data selection ICD-9 CM and ICD-10 were used: codes 084∗, 647.4, and B50–B54. Variables were gender, age, agent and origin of infection, length of stay (LOS), lethality, and comorbidities. Analysis included description, hypothesis testing, and regression. Results.There were 2003 malaria hospitalizations and 480 notified hospitalized cases, mainly in young male adults. P. falciparum was the main agent of infection acquired mainly in sub-Saharan Africa. Lethality was 1.95% and mean LOS was 8.09 days. Older age entailed longer LOS and increased lethality. Discussion. From 2000 to 2009, there were 2003 malaria hospitalizations with decreasing annual incidence, these numbers being remarkably higher than those notified. The national database of diagnosis related groups, reflecting hospitalizations on NHS hospitals, may be an unexplored complementary source for better estimates on imported malaria.
A 2D Ray-Tracing Based Model for Micro- and Millimeter-Wave Propagation Through Vegetation
Publication . Leonor, Nuno R.; Caldeirinha, Rafael F. S.; Fernandes, Telmo R.; Ferreira, David; Sánchez, Manuel García
A novel two dimensional model to characterize the electromagnetic behavior of trees has been developed with the purpose of being used in ray-tracing based simulation platforms. This model uses various point scatterers with specific radiation characteristics to describe the effect of the trees present in the radiowave propagation path. The method to extract the parameters of the point scatterers from measurements is presented. The performance of this novel formulation is assessed in a tree formation scenario against measurements results obtained in a controlled environment, inside an anechoic chamber, at 20 and 62.4 GHz. Additionally, a comparison analysis with a discretized radiative energy transfer (dRET) approach is conducted, where a relatively good agreement has been found. The absence of readily plug-in models considering propagation through and/or around vegetation makes this new tool interesting for radio planning purposes.
Competência motora e prática desportiva em crianças - Programa de Intervenção na modalidade Futebol
Publication . Rodrigues, Maria Filipe; Matos, Rui Manuel Neto e; Antunes, Raúl de Sousa Nogueira
A competência motora (CM) em idade precoce assume um papel central no desenvolvimento global da criança, sendo importante compreender de que forma intervenções em contexto desportivo podem contribuir para a sua melhoria.
O presente projeto teve como objetivo analisar o efeito de um programa de intervenção com a duração de 8 semanas, na CM e nas habilidades técnicas do futebol em crianças de 5 e 6 anos praticantes da modalidade. A intervenção foi implementada no contexto dos treinos de futebol da Associação Cultural e Recreativa de Maceirinha (ACRM), através da inclusão de dois exercícios especificamente orientados para o desenvolvimento da CM em cada sessão de treino, que decorriam duas vezes por semana. Paralelamente, procurou-se explorar as associações entre as variáveis em estudo.
A amostra foi constituída por 16 participantes com idades entre 5 e 6 anos, das quais 15 do sexo masculino e 1 do sexo feminino. Todas as crianças foram avaliadas antes e depois da intervenção, com o objetivo de verificar possíveis alterações nas variáveis em estudo. Para a avaliação da CM foram aplicados os seis testes do Motor Competence Assessment - MCA (Rodrigues et al., 2022). O desempenho técnico no futebol foi avaliado através dos testes propostos por Chatzopoulos et al. (2024), que avaliam as habilidades básicas do futebol – passe, drible, remate e controlo de bola. Adicionalmente, foi ainda implementado um sistema de medição do grau de satisfação das crianças relativamente às tarefas propostas.
Os resultados obtidos demonstram melhorias estatisticamente significativas em todas as seis provas de CM após a intervenção. Relativamente às habilidades técnicas, e após a exclusão da prova de remate por se ter revelado desajustada ao nível de desenvolvimento dos participantes, foram verificadas melhorias significativas nas provas de passe e drible. Para além disso, no momento pós-intervenção, observaram-se associações estatisticamente significativas entre a CM e o desempenho técnico, com destaque para a habilidade de drible, que apresentou correlações significativas com cinco das seis provas do MCA. Por fim observou-se uma elevada satisfação por parte das crianças ao longo das sessões. Estes resultados sugerem que a promoção da CM em idades precoces pode favorecer tanto o desenvolvimento motor como o desenvolvimento de competências técnicas específicas no futebol, parecendo sugerir uma interdependência entre estes domínios nesta fase inicial do desenvolvimento.