Introducing numerical analysis tools in engineering: a Scilab user case in electronics course

Software tools in education became popular since the widespread of personal computers. Engineering courses lead the way in this development and these tools became almost a standard. Engineering graduates are familiar with numerical analysis tools but also with simulators (e.g. electronic circuits), computer assisted design tools and others, depending on the degree. One of the main problems with these tools is when and how to start use them so that they can be beneficial to students and not mere substitutes for potentially difficult calculations or design. In this paper a software tool to be used by first year students in electronics/electricity courses is presented. The growing acknowledgement and acceptance of open source software lead to the choice of an open source software tool – Scilab, which is a numerical analysis tool – to develop a toolbox. The toolbox was developed to be used as standalone or integrated in an e-learning platform. The e-learning platform used was Moodle. The first approach was to assess the mathematical skills necessary to solve all the problems related to electronics and electricity courses. Analysing the existing circuit simulators software tools, it is clear that even though they are very helpful by showing the end result they are not so effective in the process of the students studying and self learning since they show results but not intermediate steps which are crucial in problems that involve derivatives or integrals. Also, they are not very effective in obtaining graphical results that could be used to elaborate reports and for an overall better comprehension of the results. The developed tool was based on the numerical analysis software Scilab and is a toolbox that gives their users the opportunity to obtain the end results of a circuit analysis but also the expressions obtained when derivative and integrals calculations, plot signals, obtain vector diagrams, etc. The toolbox runs entirely in the Moodle web platform and provides the same results as the standalone application. The students can use the toolbox through the web platform (in computers where they don't have installation privileges) or in their personal computers by installing both the Scilab software and the toolbox. This approach was designed for first year students from all engineering degrees that have electronics/electricity courses in their curricula.

Perfil do doente com infecção do trato urinário num serviço de ortopedia

RESUMO - As infecções do trato urinário são um problema constante nas unidades prestadoras de cuidados de saúde. Sabe-se que a incidência das mesmas é das mais elevadas em termos de infecções associadas aos cuidados de saúde, bem como acarretam fortes custos hospitalares devido ao aumento da demora média de internamento, uso de antibioterapia aumentado, entre outros. De modo a tentar compreender toda esta problemática, com a realização deste trabalho de projecto, pretende-se encontrar o perfil do doente com infecção do trato urinário num serviço de Ortopedia. Através deste mesmo perfil, tornar-se-á mais fácil uma vigilância epidemiológica e intervenções mais direccionadas ao problema em questão. Para tal, pretende-se construir um instrumento de colheita de dados que caracterize o doente de uma forma geral, antes, e durante o próprio internamento. Caso este mesmo instrumento fosse aplicado, pretender-se-ia cruzar as váriáveis concluindo eventualmente o perfil, justificando melhor o facto da existência de infecções urinárias e adequando medidas de prevenção. ------------ -ABSTRACT - The urinary infections are a constant problem in the health care facilities. It is known that the incidence of these infections is one of the biggest in terms of infections associated to health care, as well as they bring higher hospital costs, due to the middle delay of internment, the increased use of antibioterapy, as long as others. In the way of trying to understand all problems, with the realization of this work project, one intends to find the profile of the orthopedic patient with urinary infection, in the Orthopedic Service. Trough this same profile, it will be easier to do an epidemiological surveillance and more directed interventions to the problem in matter. To achieve this goal, it is claimed to build an instrument of data collection that characterizes the patient in a general way, before and during the internment. If this instrument would be applied, it would be intended to cross the variables concluding eventually the profile, justifying better the fact of the existence of urinary infection

Estrutura de financiamento das empresas start-up

Atualmente, o contexto de atuação das empresas tem sido cada vez mais desafiante dado o binómio de competitividade e crise financeira. Desta forma, a exploração de novas soluções e identificação de lacunas ou desequilíbrios no mercado torna-se imperial para o desenvolvimento das novas entidades. É com base nesta premissa que emerge o conceito de Start-Up, sendo o seu propósito o desenvolvimento de novos produtos e modelos de negócios inovadores. Como resultado, estas empresas tornam-se num elemento revitalizador do tecido económico dos países em que estão inseridas. De forma a possibilitar a potenciação das atividades desenvolvidas por estas entidades é crucial a identificação das diversas fontes de recursos financeiros e as consequentes contrapartidas exigidas. No entanto, dado o seu caráter inovador obviamente que vários são os riscos lhes estão associados, pelo que estas empresas deparam-se com mais dificuldades no momento de acesso aos recursos financeiros que pretendem. Desta forma, a presente dissertação analisa as tendências de financiamento das Start-Up tendo como motivação o facto desta temática ainda não se encontrar devidamente explorada e dado o desconhecimento desta realidade em Portugal. Neste sentido, e aliando a problemática existente com a motivação para a concretização da presente dissertação foram realizados um conjunto de inquéritos os quais foram aliados com o desenvolvimento de modelos empíricos multivariados aplicados aos dados seccionais e em painel. Os resultados alcançados com a investigação empírica permitiram concluir a influência de um conjunto de variáveis bem como justificar a orientação e estrutura de financiamento das Start-Up portuguesas. Das variáveis investigadas de ressalvar a influência significativa da Dimensão da Empresa, Estrutura de Ativos e Forma Legal no financiamento das Start-Up nacionais.

Type-based protocol conformance and aliasing control in concurrent java programs

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

Empirical models for quantification of machining damage in composite materials

Dissertação para obtenção do Grau de Doutor em Engenharia Mecânica

Conhecimento das jovens acerca da infeção genital por HPV : um estudo piloto

RESUMO - A infeção por Vírus do Papiloma Humano (HPV) constitui uma das infeções de transmissão sexual mais comuns em mulheres adolescentes e jovens sexualmente ativas, sendo responsável por 99,7% dos casos de cancro do colo do útero (CCU). O desenvolvimento de duas vacinas de segurança e eficácia comprovadas e a introdução da vacinação contra os HPV 6, 11, 16 e 18 nos programas de imunização de diversos países constituiu um marco muito importante para a investigação no âmbito do conhecimento das populações nesta temática. O presente trabalho de projeto teve como objetivo geral avaliar o conhecimento dos adolescentes/jovens entre os 15 e os 19 anos acerca da infeção genital por HPV. Foi efetuado um estudo piloto cuja amostra foi constituída por 20 jovens, género feminino, que acorreram à Consulta de Obstetrícia e Ginecologia do Adolescente dos Serviços de Assistência Médico-Social do Sindicato dos Bancários do Sul e Ilhas, acompanhadas dos respetivos encarregados de educação. Foi-lhes solicitado o consentimento informado e entregue um questionário de caráter anónimo e confidencial com questões para avaliação do conhecimento geral acerca da infeção por HPV, formas de transmissão, manifestações clínicas, prevenção, relação entre HPV e CCU e necessidades de informação. Este estudo piloto poder-se-á revelar útil na aferição de resultados quando aplicado em larga escala, para posterior avaliação comparativa do conhecimento no âmbito do HPV. Pode igualmente ser útil no desenvolvimento de mensagens apropriadas que acompanham os programas de rastreio nesta coorte, no futuro, com vista ao aumento da literacianos jovens.

Web Processing Services for Forestry and Environmental Applications

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

A framework for efficient model transformations

The reported productivity gains while using models and model transformations to develop entire systems, after almost a decade of experience applying model-driven approaches for system development, are already undeniable benefits of this approach. However, the slowness of higher-level, rule based model transformation languages hinders the applicability of this approach to industrial scales. Lower-level, and efficient, languages can be used but productivity and easy maintenance seize to exist. The abstraction penalty problem is not new, it also exists for high-level, object oriented languages but everyone is using them now. Why is not everyone using rule based model transformation languages then? In this thesis, we propose a framework, comprised of a language and its respective environment, designed to tackle the most performance critical operation of high-level model transformation languages: the pattern matching. This framework shows that it is possible to mitigate the performance penalty while still using high-level model transformation languages.

Optimisation and design of post-tensioning anchorage corner blisters in concrete box girder bidges

The design of anchorage blisters of internal continuity post-tensioning tendons of bridges built by the cantilever method, presents some peculiarities, not only because they are intermediate anchorages but also because these anchorages are located in blisters, so the prestressing force has to be transferred from the blister the bottom slab and web of the girder. The high density of steel reinforcement in anchorage blisters is the most common reason for problems with concrete cast in situ, resulting in zones with low concrete compacity, leading to concrete crushing failures under the anchor plates. A solution may involve improving the concrete compression and tensile strength. To meet these requirements a high-performance fibre reinforced self-compacting mix- ture (HPFRC) was used in anchorage corner blisters of post-tensioning tendons, reducing the concrete cross-section and decreasing the reinforcement needed. To assess the ultimate capacity and the adequate serviceability of the local anchorage zone after reducing the minimum concrete cross-section and the confining reinforcement, specified by the anchorage device supplier for the particular tendon, load transfer tests were performed. To investigate the behaviour of anchorage blisters regarding the transmission of stresses to the web and the bottom slab of the girder, and the feasibility of using high performance concrete only in the blister, two half scale models of the inferior corner of a box girder existing bridge were studied: a reference specimen of ordinary reinforced concrete and a HPFRC blister specimen. The design of the reinforcement was based in the tensile forces obtained on strut-and-tie models. An experimental program was carried out to assess the models used in design and to study the feasibility of using high performance concrete only in the blister, either with casting in situ, or with precast solutions. A non-linear finite element analysis of the tested specimens was also performed and the results compared.

A public transport bus assignment problem: parallel metaheuristics assessment

Combinatorial Optimization Problems occur in a wide variety of contexts and generally are NP-hard problems. At a corporate level solving this problems is of great importance since they contribute to the optimization of operational costs. In this thesis we propose to solve the Public Transport Bus Assignment problem considering an heterogeneous fleet and line exchanges, a variant of the Multi-Depot Vehicle Scheduling Problem in which additional constraints are enforced to model a real life scenario. The number of constraints involved and the large number of variables makes impracticable solving to optimality using complete search techniques. Therefore, we explore metaheuristics, that sacrifice optimality to produce solutions in feasible time. More concretely, we focus on the development of algorithms based on a sophisticated metaheuristic, Ant-Colony Optimization (ACO), which is based on a stochastic learning mechanism. For complex problems with a considerable number of constraints, sophisticated metaheuristics may fail to produce quality solutions in a reasonable amount of time. Thus, we developed parallel shared-memory (SM) synchronous ACO algorithms, however, synchronism originates the straggler problem. Therefore, we proposed three SM asynchronous algorithms that break the original algorithm semantics and differ on the degree of concurrency allowed while manipulating the learned information. Our results show that our sequential ACO algorithms produced better solutions than a Restarts metaheuristic, the ACO algorithms were able to learn and better solutions were achieved by increasing the amount of cooperation (number of search agents). Regarding parallel algorithms, our asynchronous ACO algorithms outperformed synchronous ones in terms of speedup and solution quality, achieving speedups of 17.6x. The cooperation scheme imposed by asynchronism also achieved a better learning rate than the original one.

Use of nonradioactive labeling to detect large gene rearrangements in 21-hydroxylase deficiency

PURPOSE: To establish the Southern blotting technique using hybridization with a nonradioactive probe to detect large rearrangements of CYP21A2 in a Brazilian cohort with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH-21OH). METHOD: We studied 42 patients, 2 of them related, comprising 80 non-related alleles. DNA samples were obtained from peripheral blood, digested by restriction enzyme Taq I, submitted to Southern blotting and hybridized with biotin-labeled probes. RESULTS: This method was shown to be reliable with results similar to the radioactive-labeling method. We found CYP21A2 deletion (2.5%), large gene conversion (8.8%), CYP21AP deletion (3.8%), and CYP21A1P duplication (6.3%). These frequencies were similar to those found in our previous study in which a large number of cases were studied. Good hybridization patterns were achieved with a smaller amount of DNA (5 mug), and fragment signs were observed after 5 minutes to 1 hour of exposure. CONCLUSIONS: We established a non-radioactive (biotin) Southern blot/hybridization methodology for CYP21A2 large rearrangements with good results. Despite being more arduous, this technique is faster, requires a smaller amount of DNA, and most importantly, avoids problems with the use of radioactivity.

A case study on the conversion of an internal combustion engine vehicle into an electric vehicle

This paper presents the conversion process of a traditional Internal Combustion Engine vehicle into an Electric Vehicle. The main constitutive elements of the Electric Vehicle are presented. The developed powertrain uses a three-phase inverter with Field Oriented Control and space vector modulation. The developed on-board batteries charging system can operate in Grid-to-Vehicle and Vehicle-to-Grid modes. The implemented prototypes were tested, and experimental results are presented. The assembly of these prototypes in the vehicle was made in accordance with the Portuguese legislation about vehicles conversion, and the main adopted solutions are presented.

Non emergency patients transport - a mixed integer linear programming

This work presents a model and a heuristic to solve the non-emergency patients transport (NEPT) service issues given the new rules recently established in Portugal. The model follows the same principle of the Team Orienteering Problem by selecting the patients to be included in the routes attending the maximum reduction in costs when compared with individual transportation. This model establishes the best sets of patients to be transported together. The model was implemented in AMPL and a compact formulation was solved using NEOS Server. A heuristic procedure based on iteratively solving problems with one vehicle was presented, and this heuristic provides good results in terms of accuracy and computation time.

Pensar, testar, opinar e construir: a resolução de problemas no jardim de infância e primeiro ciclo

Relatório de estágio de mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico

A sixth-order finite volume method for the 1D biharmonic operator: application to intramedullary nail simulation

A new very high-order finite volume method to solve problems with harmonic and biharmonic operators for one- dimensional geometries is proposed. The main ingredient is polynomial reconstruction based on local interpolations of mean values providing accurate approximations of the solution up to the sixth-order accuracy. First developed with the harmonic operator, an extension for the biharmonic operator is obtained, which allows designing a very high-order finite volume scheme where the solution is obtained by solving a matrix-free problem. An application in elasticity coupling the two operators is presented. We consider a beam subject to a combination of tensile and bending loads, where the main goal is the stress critical point determination for an intramedullary nail.