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Browsing by Issue Date, starting with "2009"

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  • Inexpensive solution for real-time video and image stitching
    Publication . Quintal, Filipe Magno Gouveia
    Image stitching is the process of joining several images to obtain a bigger view of a scene. It is used, for example, in tourism to transmit to the viewer the sensation of being in another place. I am presenting an inexpensive solution for automatic real time video and image stitching with two web cameras as the video/image sources. The proposed solution relies on the usage of several markers in the scene as reference points for the stitching algorithm. The implemented algorithm is divided in four main steps, the marker detection, camera pose determination (in reference to the markers), video/image size and 3d transformation, and image translation. Wii remote controllers are used to support several steps in the process. The built‐in IR camera provides clean marker detection, which facilitates the camera pose determination. The only restriction in the algorithm is that markers have to be in the field of view when capturing the scene. Several tests where made to evaluate the final algorithm. The algorithm is able to perform video stitching with a frame rate between 8 and 13 fps. The joining of the two videos/images is good with minor misalignments in objects at the same depth of the marker,misalignments in the background and foreground are bigger. The capture process is simple enough so anyone can perform a stitching with a very short explanation. Although real‐time video stitching can be achieved by this affordable approach, there are few shortcomings in current version. For example, contrast inconsistency along the stitching line could be reduced by applying a color correction algorithm to every source videos. In addition, the misalignments in stitched images due to camera lens distortion could be eased by optical correction algorithm. The work was developed in Apple’s Quartz Composer, a visual programming environment. A library of extended functions was developed using Xcode tools also from Apple.
    2009Master thesis Open access Show more
  • Aprendendo descobrindo: a aprendizagem da matemática num ambiente escolar não tradicional
    Publication . Vieira, Carolina Pereira
    Este estudo foi realizado no âmbito do Mestrado em Ensino de Matemática do 3º Ciclo do Ensino Básico e do Secundário da Universidade da Madeira no ano lectivo 2008/2009 e tem como objectivo apresentar em traços gerais o trabalho realizado por mim e pelo meu grupo ao longo do estágio pedagógico, assim como analisar e discutir a actividade matemática dos alunos ao longo de uma unidade curricular em especial, quando em contacto com estratégias de ensino apoiadas na aprendizagem pela descoberta e inspiradas nas práticas utilizadas na Escola da Ponte. Com o passar do tempo, a sociedade desenvolveu uma necessidade eminente de competências que o ensino tradicional não é capaz de fomentar nos seus alunos. Ciente desta carência, procurei adaptar as metodologias utilizadas na Escola da Ponte aos alunos de uma turma de 8º ano e analisei as reacções dos mesmos face às novas oportunidades de aprendizagem proporcionadas.
    2009Master thesis Open access Show more
  • Irene Lucília Andrade: resgate(s) do passado para um questionamento do presente
    Publication . Coelho, Leonor Martins
    Cremos encontrar na obra de Irene Lucília Andrade, num resgate constante de um tempo findo, a exaltação das relações afetivas que a era da globalização tende a apagar. Com efeito, a escrita desta autora nascida na ilha da Madeira tece uma crítica ao presente da cultura da ostentação, apelando, a voz do texto, à cultura pretérita do afeto. Por razões de ordem prática, percorrer-se-á de uma forma necessariamente sumária dois textos da referida escritora: um livro de poemas e uma compilação de narrativas breves. Por um lado, Água de Mel e Manacá (2002), por outro, A Penteada ou o Fim do Caminho (2004), uma vez que ambos os livros apelam à preservação de vivências de outrora, alicerçadas no reconhecimento de laços fraternos, por oposição a uma cultura da indiferença e do provento fácil que parece vir, paulatinamente, a caraterizar a sociedade atual. Nessa cultura da memória que tem vindo a marcar quer a poesia, quer a narrativa, a sua produção surge como um testemunho de uma consciência crítica, nascida de um sentimento de perda da cultura da fraternidade e da humildade. A memória do tempo pretérito não somente recupera a existência do passado como permite pensar o presente, perspetivando, ainda, o futuro desejado. Assim, o poder construtivo da recordação abre um espaço de questionamento e revelam novas convergências numa completude que se alicerce nos valores da consolidação da amizade, no reatar de laços sociais, para poder voltar, novamente, a recuperar o que foi desaparecendo ao sabor da megalomania do homem moderno.
    2009Journal article Open access Show more
  • Cross-validation of the Beunen–Malina method to predict adult height
    Publication . Beunen, Gaston P.; Malina, Robert M.; Freitas, Duarte L.; Maia, José A.; Claessens, Albrecht L.; Gouveia, Élvio R.; Lefevre, Johan
    The purpose of this study was to cross-validate the Beunen–Malina method for non-invasive prediction of adult height. Three hundred and eight boys aged 13, 14, 15 and 16 years from the Madeira Growth Study were observed at annual intervals in 1996, 1997 and 1998 and re-measured 7–8 years later. Height, sitting height and the triceps and subscapular skinfolds were measured; skeletal age was assessed using the Tanner–Whitehouse 2 method. Adult height was measured and predicted using the Beunen–Malina method. Maturity groups were classified using relative skeletal age (skeletal age minus chronological age). Pearson correlations, mean differences and standard errors of estimate (SEE) were calculated. Age-specific correlations between predicted and measured adult height vary between 0.70 and 0.85, while age-specific SEE varies between 3.3 and 4.7 cm. The correlations and SEE are similar to those obtained in the development of the original Beunen–Malina method. The Beunen– Malina method is a valid method to predict adult height in adolescent boys and can be used in European populations or populations from European ancestry. Percentage of predicted adult height is a non-invasive valid method to assess biological maturity.
    2009Journal article Open access Show more
  • 2009Book part Open access Show more
  • Karyological analysis of the five native Macaronesian Festuca (Gramineae) grasses supports a distinct diploid origin of two schizoendemic groups
    Publication . Sequeira, Miguel Menezes de; Díaz-Pérez, Antonio; Santos-Guerra, Arnoldo; Viruel, Juan; Catalán, Pilar
    Menezes de Sequeira, M., Díaz-Pérez, A., Santos-Guerra, A., Viruel, J. & Catalán, P. 2009. Karyological analysis of the five na tive Macaronesian Festuca (Gramineae) grasses supports a dis tinct diploid origin of two schizoendemic groups. Anales Jard. Bot. Madrid 66(1): 55-63. A karyological analysis has been conducted of all five native Macaronesian Festuca grasses belonging to fine-leaved F. subg. Festuca sect. Aulaxyper and broad-leaved F. subg. Drymanthele sect. Phaeochloa Loliinae lineages. Chromosomal analyses were made in 30 plants corresponding to 17 populations of the fine leaved F. agustinii, F. jubata, F. francoi and F. petraea and 2 pop ulations of the broad-leaved F. donax. All counts except one tetraploid count were diploids, showing 2n = 14 chromosomes. Diploidy was confirmed for the robust F. donax, nested within a clade of relict ancestral fescues as reported in recent phyloge netic studies, and was also found in the more slender F. agus tinii, F. jubata, F. francoi and F. petraea, which are basal to a re cently evolved clade of polyploid red fescues. Karyotypes of the two groups are however distinct, with broad-leaved F. donax showing larger and more regular chromosomes and all four fine-leaved taxa showing smaller and more irregular submeta centric chromosomes. Our karyological data indicate that these two groups of diploid fescues correspond to distinct schizoen demics which apparently originated at different times after in dependent continental colonizations of Macaronesia
    2009Journal article Open access Show more
  • JML- Based formal development of a Java card application for managing medical appointments
    Publication . Rodrigues, Ricardo Miguel Soares
    Although formal methods can dramatically increase the quality of software systems, they have not widely been adopted in software industry. Many software companies have the perception that formal methods are not cost-effective cause they are plenty of mathematical symbols that are difficult for non-experts to assimilate. The Java Modelling Language (short for JML) Section 3.3 is an academic initiative towards the development of a common formal specification language for Java programs, and the implementation of tools to check program correctness. This master thesis work shows how JML based formal methods can be used to formally develop a privacy sensitive Java application. This is a smart card application for managing medical appointments. The application is named HealthCard. We follow the software development strategy introduced by João Pestana, presented in Section 3.4. Our work influenced the development of this strategy by providing hands-on insight on challenges related to development of a privacy sensitive application in Java. Pestana’s strategy is based on a three-step evolution strategy of software specifications, from informal ones, through semiformal ones, to JML formal specifications. We further prove that this strategy can be automated by implementing a tool that generates JML formal specifications from a welldefined subset of informal software specifications. Hence, our work proves that JML-based formal methods techniques are cost-effective, and that they can be made popular in software industry. Although formal methods are not popular in many software development companies, we endeavour to integrate formal methods to general software practices. We hope our work can contribute to a better acceptance of mathematical based formalisms and tools used by software engineers. The structure of this document is as follows. In Section 2, we describe the preliminaries of this thesis work. We make an introduction to the application for managing medical applications we have implemented. We also describe the technologies used in the development of the application. This section further illustrates the Java Card Remote Method Invocation communication model used in the medical application for the client and server applications. Section 3 introduces software correctness, including the design by contract and the concept of contract in JML. Section 4 presents the design structure of the application. Section 5 shows the implementation of the HealthCard. Section 6 describes how the HealthCard is verified and validated using JML formal methods tools. Section 7 includes some metrics of the HealthCard implementation and specification. Section 8 presents a short example of how a client-side of a smart card application can be implemented while respecting formal specifications. Section 9 describes a prototype tools to generate JML formal specifications from informal specifications automatically. Section 10 describes some challenges and main ideas came acrorss during the development of the HealthCard. The full formal specification and implementation of the HealthCard smart card application presented in this document can be reached at https://sourceforge.net/projects/healthcard/.
    2009Master thesis Open access Show more
  • Balance-bot
    Publication . Abreu, Victor Vicente
    Research on inverted pendulum has gained momentum over the last decade on a number of robotic laboratories over the world; due to its unstable proprieties is a good example for control engineers to verify a control theory. To verify that the pendulum can balance we can make some simulations using a closed-loop controller method such as the linear quadratic regulator or the proportional–integral–derivative method. Also the idea of robotic teleoperation is gaining ground. Controlling a robot at a distance and doing that precisely. However, designing the tool to takes the best benefit of the human skills while keeping the error minimal is interesting, and due to the fact that the inverted pendulum is an unstable system it makes a compelling test case for exploring dynamic teleoperation. Therefore this thesis focuses on the construction of a two-wheel inverted pendulum robot, which sensor we can use to do that, how they must be integrated in the system and how we can use a human to control an inverted pendulum. The inverted pendulum robot developed employs technology like sensors, actuators and controllers. This Master thesis starts by presenting an introduction to inverted pendulums and some information about related areas such as control theory. It continues by describing related work in this area. Then we describe the mathematical model of a two-wheel inverted pendulum and a simulation made in Matlab. We also focus in the construction of this type of robot and its working theory. Because this is a mobile robot we address the theme of the teleoperation and finally this thesis finishes with a general conclusion and ideas of future work.
    2009Master thesis Open access Show more
  • HLA polymorphysms in Forros and Angolares from São Tomé Island (West Africa): evidence for the population origin
    Publication . Saldanha, Nádia; Spínola, Carla; Santos, Margarida R.; Simões, Joaquim P.; Bruges-Armas, Jácome; Brehm, António; Spínola, Hélder
    2009Journal article Open access Show more
  • Vulnerabilidade ao stress, estratégias de coping e autoeficácia em professores portugueses
    Publication . Pocinho, Margarida; Capelo, Maria Regina Teixeira Ferreira
    Neste trabalho, apresentamos uma investigação realizada com professores, no qual se procura determinar a vulnerabilidade ao stress ; identificar as principais fontes de stress ; estabelecer as principais estratégias de coping; analisar se as estratégias deste condicionam a presença de stress laboral; e reconhecer se a autoeficácia percebida é preditora desse tipo de stress . Trata-se duma investigação por questionário, do tipo correlacional, e a amostra é constituída por 54 professores do Ensino Básico público português. As respostas ao Questionário sociodemográfico e profissional; ao Questionário de Vulnerabilidade ao Stress — 23QVS (Serra, 2000); ao Questionário de Stress nos Professores — QSP (Gomes et al ., 2006; Gomes, 2007); ao Coping Job Scale — CJS de Latack (adaptação de Jesus & Pereira, 1994); e à Escala de Avaliação de Autoeficácia Geral (Ribeiro, 1995) revelam que 20,4% dos docentes são vulneráveis ao stress ; os comportamentos inadequados/indisciplina dos alunos são as principais fontes de stress ; as estratégias de controlo são as mais utilizadas pelos participantes para enfrentar o stress , seguidas das de escape e das de gestão de sintomas. Os professores não vulneráveis ao stress utilizam principalmente estratégias de controlo e apresentam níveis mais elevados de eficácia perante a adversidade, bem como de iniciativa e persistência em relação aos professores vulneráveis ao stress
    2009Journal article Open access Show more