Estudo da percepção dos problemas de usabilidade de um software relacionados com o desempenho dos processos cognitivos

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Concepção de uma aplicação móvel no âmbito da ecologia e sustentabilidade ambiental

Trabalho de projeto apresentado à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Um site, um conteúdo e incontáveis dispositivos: as estratégias de design utilizadas para ambientes multiplataformas

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

O design do manual escolar

O manual escolar, pelas suas características, é um produto de design gráfico, disciplina que tardou a desenvolver-se em Portugal. Após o 25 de Abril, as editoras escolares expandiram-se, e a globalização do ensino teve como consequência o aumento do número de manuais escolares. O desenvolvimento do design gráfico está intimamente ligado ao desenvolvimento da tecnologia informática, contribuindo fortemente para a alteração das características do manual escolar, sendo a mais notória a importância dada à imagem como portadora de informação. Sem investigação que suporte o seu actual formato, nem formação dos professores que permita explorar as suas novas potencialidades, interrogamo-nos sobre a sua eficácia. O campo da teoria da imagem é vasto e a sua aplicação, quer na realização, quer na exploração pedagógica do manual escolar, exige alguma sistematização que procuramos apresentar.

Design of improved rail-to-rail low-distortion and low-stress switches in advanced CMOS technologies

This paper describes the efficient design of an improved and dedicated switched-capacitor (SC) circuit capable of linearizing CMOS switches to allow SC circuits to reach low distortion levels. The described circuit (SC linearization control circuit, SLC) has the advantage over conventional clock-bootstrapping circuits of exhibiting low-stress, since large gate voltages are avoided. This paper presents exhaustive corner simulation results of a SC sample-and-hold (S/H) circuit which employs the proposed and optimized circuits, together with the experimental evaluation of a complete 10-bit ADC utilizing the referred S/H circuit. These results show that the SLC circuits can reduce distortion and increase dynamic linearity above 12 bits for wide input signal bandwidths.

Optimal design of piezolaminated structures using B-spline strip finite element models

A package of B-spline finite strip models is developed for the linear analysis of piezolaminated plates and shells. This package is associated to a global optimization technique in order to enhance the performance of these types of structures, subjected to various types of objective functions and/or constraints, with discrete and continuous design variables. The models considered are based on a higher-order displacement field and one can apply them to the static, free vibration and buckling analyses of laminated adaptive structures with arbitrary lay-ups, loading and boundary conditions. Genetic algorithms, with either binary or floating point encoding of design variables, were considered to find optimal locations of piezoelectric actuators as well as to determine the best voltages applied to them in order to obtain a desired structure shape. These models provide an overall economy of computing effort for static and vibration problems.

Estudo do sobre o impacto do risco biológico e ambiental na qualidade da interacção mãe-filho(a)

O presente estudo exploratório tem como principais objectivos: averiguar o impacto do risco biológico e ambiental, ou ambos, na interacção mãe-filho(a), e contribuir para a adaptação de uma escala de observação da qualidade da interacção mãe-filho(a) em interacção livre. Para o efeito observámos 40 díades mãe-filho(a) em jogo livre distribuídas por 4 grupos de estudo: o primeiro grupo composto por 14 díades sem condições assinaláveis de risco, o segundo grupo composto por 8 díades assinaláveis de risco biológico, o terceiro grupo composto por 7 díades em risco ambiental e por fim, o quarto grupo por 10 díades em risco ambiental e biológico. A recolha de dados foi realizada nos concelhos do Porto e Viseu. A qualidade de interacção foi inicialmente observada em 50 casos com a Escala de Comportamentos Interactivos dos bebés e das mães em jogo livre (Fuertes, Faria, Oliveira-Costa & Soares, 2010), tendo sido posteriormente adaptada para condições de risco tomando a designação de escala Escala de Avaliação de Comportamentos Interactivos mãe-filho(a)-Adaptada para Condições de Risco (Fuertes & Canelhas, 2011). Os comportamentos maternos e infantis foram cotados, independentemente, relativamente à expressão facial, expressão vocal, expressão afectiva, posicionamento, directividade e jogo. Os resultados foram analisados com recurso a estatística descritiva e multinominal. Os resultados do nosso estudo sugerem que as díades sem condições de risco tinham interacções mais positivas, recíprocas e ajustadas à idade das crianças, do que as díades sujeitas, quer a situações de risco biológico, quer a condições de risco ambiental. Adicionalmente, verificámos que alguns factores demográficos (e.g., risco na gravidez, área de residência, estabilidade profissional das mães e a frequência de creche (em oposição a amas) afectam a qualidade da interacção mãe-filho(a). Por fim, encontramos uma forte concordância entre as duas escalas, sugerindo que a nossa escala (Escala de Avaliação de Comportamentos Interactivos mãe-filho(a)-Adaptada para Situações de Risco), tem indicadores capazes de captar a natureza interactiva do jogo mãe-filho(a) e deverá ser validada.

Design of a sea-level tsunami detection network for the Gulf of Cadiz

The devastating impact of the Sumatra tsunami of 26 December 2004, raised the question for scientists of how to forecast a tsunami threat. In 2005, the IOC-UNESCO XXIII assembly decided to implement a global tsunami warning system to cover the regions that were not yet protected, namely the Indian Ocean, the Caribbean and the North East Atlantic, the Mediterranean and connected seas (the NEAM region). Within NEAM, the Gulf of Cadiz is the more sensitive area, with an important record of devastating historical events. The objective of this paper is to present a preliminary design for a reliable tsunami detection network for the Gulf of Cadiz, based on a network of sea-level observatories. The tsunamigenic potential of this region has been revised in order to define the active tectonic structures. Tsunami hydrodynamic modeling and GIS technology have been used to identify the appropriate locations for the minimum number of sea-level stations. Results show that 3 tsunameters are required as the minimum number of stations necessary to assure an acceptable protection to the large coastal population in the Gulf of Cadiz. In addition, 29 tide gauge stations could be necessary to fully assess the effects of a tsunami along the affected coasts of Portugal, Spain and Morocco.

MDAI: Model based Design in Automobile Industry

It is proposed a new approach based on a methodology, assisted by a tool, to create new products in the automobile industry based on previous defined processes and experiences inspired on a set of best practices or principles: it is based on high-level models or specifications; it is component-based architecture centric; it is based on generative programming techniques. This approach follows in essence the MDA (Model Driven Architecture) philosophy with some specific characteristics. We propose a repository that keeps related information, such as models, applications, design information, generated artifacts and even information concerning the development process itself (e.g., generation steps, tests and integration milestones). Generically, this methodology receives the users' requirements to a new product (e.g., functional, non-functional, product specification) as its main inputs and produces a set of artifacts (e.g., design parts, process validation output) as its main output, that will be integrated in the engineer design tool (e.g. CAD system) facilitating the work.

New Steel Alloys for the Design of Heat Recovery Steam Generator Components of Combined Cycle Gas Plants

Demand for power is growing every day, mainly due to emerging economies in countries such as China, Russia, India, and Brazil. During the last 50 years steam pressure and temperature in power plants have been continuously raised to improve thermal efficiency. Recent efforts to improve efficiency leads to the development of a new generation of heat recovery steam generator, where the Benson once-through technology is applied to improve the thermal efficiency. The main purpose of this paper is to analyze the mechanical behavior of a high pressure superheater manifold by applying finite element modeling and a finite element analysis with the objective of analyzing stress propagation, leading to the study of damage mechanism, e.g., uniaxial fatigue, uniaxial creep for life prediction. The objective of this paper is also to analyze the mechanical properties of the new high temperature resistant materials in the market such as 2Cr Bainitic steels (T/P23 and T/P24) and also the 9-12Cr Martensitic steels (T/P91, T/P92, E911, and P/T122). For this study the design rules for construction of power boilers to define the geometry of the HPSH manifold were applied.

Viability of Two New Mixture Design Methodologies for Self-Consolidating Concrete

This paper presents the results from an experimental study of the technical viability of two mixture designs for self-consolidating concrete (SCC) proposed by two Portuguese researchers in a previous work. The objective was to find the best method to provide the required characteristics of SCC in fresh and hardened states without having to experiment with a large number of mixtures. Five SCC mixtures, each with a volume of 25 L (6.61 gal.) were prepared using a forced mixer with a vertical axis for each of three compressive strength targets: 40, 55, and 70 MPa (5.80, 7.98, and 10.15 ksi). The mixtures' fresh state properties of fluidity, segregation resistance ability, and bleeding and blockage tendency, and their hardened state property of compressive strength were compared. For this study, the following tests were performed. slump-flow, V-funnel, L-box, box, and compressive strength. The results of this study made it possible to identify the most influential factors in the design of the SCC mixtures.

Reactividade infantil e a qualidade da interacção mãe-filho

No quadro dos estudos sobre o relacionamento mãe-filho, procurámos averiguar a relação entre a reactividade infantil observada em condições de stress e a qualidade do comportamento interactivo infantil e materno em jogo livre. Para o efeito, seleccionámos uma amostrade 40 díades mãe-filho cujos bebés tinham cerca de 3 meses e não apresentavam nenhuma condição declarada de risco. A qualidade da interacção mãe-filho foi avaliada em jogo livre através da escala CARE-Index. Para testar a reactividade infantil submetemos os bebés à situação experimental Still-Face. Os resultados mostram que a reactividade infantil expressa naquela situação laboratorial não é independente do comportamento dos bebés em jogo livre. Com efeito, os bebés com maior dificuldade em conformar-se com a ausência de resposta materna apresentam um comportamento menos cooperativo e difícil em jogo livre. Em sentido inverso, os bebés que em jogo livre são menos participativos apresentam menores índices de reactividade negativa quando a mãe mantém a cara inexpressiva. Em termos diádicos, verificamos que existe uma forte correlação entre o comportamento cooperativo do bebé e a sensibilidade materna em jogo livre. Os resultados são discutidos no quadro do desenvolvimento dos processos de interacção mãe e filho.

Design of a new test chamber for evaluation of the toxicity of rubber infill

A test chamber was projected and built (according to ISO 16000-9 Standard) to simulate atmospheric conditions experienced by rubber infill (when applied in synthetic turf pitches) and measure accurately the airborne emissions of pollutants such as dusts and volatile organic compounds (VOC), as well as pollutants present in leachates. It should be pointed out that standard ISO 16000-9 is only concerned with the determination of the emission of VOC from building products and furnishing (not specific of synthetic turf materials), whereas other standards are concerned with the emission of leachates only. This procedure is to be considered as a technical option to the lysimeter "global turf system evaluation" when the rubber infill alone is to be evaluated. The advantage of the proposed option considering this "test chamber" is its simplicity and economy. This test chamber is actually installed and being used for tests in LAIST.

Optical Filter Design Using Background Wavelength Processing Techniques

Amorphous SiC tandem heterostructures are used to filter a specific band, in the visible range. Experimental and simulated results are compared to validate the use of SiC multilayered structures in applications where gain compensation is needed or to attenuate unwanted wavelengths. Spectral response data acquired under different frequencies, optical wavelength control and side irradiations are analyzed. Transfer function characteristics are discussed. Color pulsed communication channels are transmitted together and the output signal analyzed under different background conditions. Results show that under controlled wavelength backgrounds, the device sensitivity is enhanced in a precise wavelength range and quenched in the others, tuning or suppressing a specific band. Depending on the background wavelength and irradiation side, the device acts either as a long-, a short-, or a band-rejection pass filter. An optoelectronic model supports the experimental results and gives insight on the physics of the device.

Optimal design for active damping in sandwich structures using the Direct MultiSearch method

This paper addresses the problem of optimal positioning of surface bonded piezoelectric patches in sandwich plates with viscoelastic core and laminated face layers. The objective is to maximize a set of modal loss factors for a given frequency range using multiobjective topology optimization. Active damping is introduced through co-located negative velocity feedback control. The multiobjective topology optimization problem is solved using the Direct MultiSearch Method. An application to a simply supported sandwich plate is presented with results for the maximization of the first six modal loss factors. The influence of the finite element mesh is analyzed and the results are, to some extent, compared with those obtained using alternative single objective optimization. (C) 2013 Elsevier Ltd. All rights reserved.