Transverse Vibrations in Beams Supported by a Piece-Wise Homogeneous Visco- Elastic Foundation

Transversal vibrations induced by a load moving uniformly along an infinite beam resting on a piece-wise homogeneous visco-elastic foundation are studied. Special attention is paid to the additional vibrations, conventionally referred to as transition radiations, which arise as the point load traverses the place of foundation discontinuity. The governing equations of the problem are solved by the normalmode analysis. The solution is expressed in a form of infinite sum of orthogonal natural modes multiplied by the generalized coordinate of displacement. The natural frequencies are obtained numerically exploiting the concept of the global dynamic stiffness matrix. This ensures that the frequencies obtained are exact. The methodology has restrictions neither on velocity nor on damping. The approach looks simple, though, the numerical expression of the results is not straightforward. A general procedure for numerical implementation is presented and verified. To illustrate the utility of the methodology parametric optimization is presented and influence of the load mass is studied. The results obtained have direct application in analysis of railway track vibrations induced by high-speed trains when passing regions with significantly different foundation stiffness.

Avatars and the «Imitation Game» – can machines smile?

Considering Alan Turing’s challenge in «Computing Machinery and Intelligence» (1950) – can machines play the «imitation game»? – it is proposed that the requirements of the Turing test are already implicitly being used for checking the credibility of virtual characters and avatars. Like characters, Avatars aim to visually express emotions (the exterior signs of the existence of feeling) and its creators have to resort to emotion codes. Traditional arts have profusely contributed for this field and, together with the science of anatomy, shaped the grounds for current Facial Action Coding System (FACS) and their databases. However, FACS researchers have to improve their «instruction tables» so that the machines will be able, in a near future, to be programmed to carry out the operation of recognizing human expressions (face and body) and classify them adequately. For the moment, the reproductions have to resort to the copy of real life expressions, and the presente smile of avatars comes from mirroring their human users.

Experimental design methodologies for the identification of Michaelis-Menten type kinetics

The main objective of this work was to investigate the application of experimental design techniques for the identification of Michaelis-Menten kinetic parameters. More specifically, this study attempts to elucidate the relative advantages/disadvantages of employing complex experimental design techniques in relation to equidistant sampling when applied to different reactor operation modes. All studies were supported by simulation data of a generic enzymatic process that obeys to the Michaelis-Menten kinetic equation. Different aspects were investigated, such as the influence of the reactor operation mode (batch, fed-batch with pulse wise feeding and fed-batch with continuous feeding) and the experimental design optimality criteria on the effectiveness of kinetic parameters identification. The following experimental design optimality criteria were investigated: 1) minimization of the sum of the diagonal of the Fisher information matrix (FIM) inverse (A-criterion), 2) maximization of the determinant of the FIM (D-criterion), 3) maximization of the smallest eigenvalue of the FIM (E-criterion) and 4) minimization of the quotient between the largest and the smallest eigenvalue (modified E-criterion). The comparison and assessment of the different methodologies was made on the basis of the Cramér-Rao lower bounds (CRLB) error in respect to the parameters vmax and Km of the Michaelis-Menten kinetic equation. In what concerns the reactor operation mode, it was concluded that fed-batch (pulses) is better than batch operation for parameter identification. When the former operation mode is adopted, the vmax CRLB error is lowered by 18.6 % while the Km CRLB error is lowered by 26.4 % when compared to the batch operation mode. Regarding the optimality criteria, the best method was the A-criterion, with an average vmax CRLB of 6.34 % and 5.27 %, for batch and fed-batch (pulses), respectively, while presenting a Km’s CRLB of 25.1 % and 18.1 %, for batch and fed-batch (pulses), respectively. As a general conclusion of the present study, it can be stated that experimental design is justified if the starting parameters CRLB errors are inferior to 19.5 % (vmax) and 45% (Km), for batch processes, and inferior to 42 % and to 50% for fed-batch (pulses) process. Otherwise equidistant sampling is a more rational decision. This conclusion clearly supports that, for fed-batch operation, the use of experimental design is likely to largely improve the identification of Michaelis-Menten kinetic parameters.

Climate change impacts on portuguese energy system in 2050

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas Ambientais

Extensible metadata repository for information systems

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer Science

Economies of scale and scope in the provision of diagnostic techniques and therapeutic services in Portuguese hospitals

This paper analyses the provision of auxiliary clinical services that are typically carried out within the hospital. We estimate a exible cost function for the three most important (cost- wise) diagnostic techniques and therapeutic services in Portuguese hospitals: Clinical Pathology, Medical Imaging and Physical Medicine and Rehabilitation. Our objective in carrying out this estimation is the evaluation of economies of scale and scope in the provision of these services. For all services, we nd evidence of ray economies of scale and some evidence of economies of scope. These results have important policy implications and can be related to the ongoing discussion of where and how should hospitals provide these services.

Human and climatic change impact modelling on the habitat suitability for the chimpanzee (Pan troglodytes ellioti) – Case study: The proposed Mount Cameroon National Park

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

Spatial neighborhood matrix computation: Inverse distance weighted versus binary contiguity

Paper presented at Geo-Spatial Crossroad GI_Forum, Salzburg, Austria.

Framework development for providing accessibility to qualitative spatial calculi

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

Validation of NASA rotor 67 with openFOAM's transonic density-based solver

Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica

Growth Accounting: How institutions affect Portugal's Growth

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

Watershed-scale runoff routing and solute transport in a spatially aggregated hydrological framework

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

Imitação e Retórica em Corte na Aldeia de Francisco Rodrigues Lobo

Corte na Aldeia (1619), de Francisco Rodrigues Lobo, é o primeiro manual de cortesania em língua portuguesa, inspirado por Il Cortegiano (1528), de Baldesar Castiglione, a obra-matriz do género. Em tempo de usurpação do trono português por Castela, é necessário “resgatar” a glória da antiga corte, que servirá de base à escrita de um manual destinado a formar o cortesão do futuro, o “discreto”, na sua expressão mais exigente. Este, investido da devida doutrina, poderá entretanto brilhar numa corte política e simbolicamente dispersa “pelas aldeias”. Ora, o domínio da eloquência e a adopção de uma retórica apropriada ao trato cortesão, assente numa língua portuguesa “renascida”, constituem as ferramentas essenciais de que importa munir o aspirante a cortesão, que, neste início do século XVII, poderá até ser originário da burguesia.

Instrumental Fado: a generative interactive system

Fado was listed as UNESCO Intangible Cultural Heritage in 2011. This dissertation describes a theoretical model, as well as an automatic system, able to generate instrumental music based on the musics and vocal sounds typically associated with fado’s practice. A description of the phenomenon of fado, its musics and vocal sounds, based on ethnographic, historical sources and empirical data is presented. The data includes the creation of a digital corpus, of musical transcriptions, identified as fado, and statistical analysis via music information retrieval techniques. The second part consists in the formulation of a theory and the coding of a symbolic model, as a proof of concept, for the automatic generation of instrumental music based on the one in the corpus.

CTT, the mail going public

The main purpose of this case-study is to analyse CTT’s privatisation process, a previously Government-owned firm, which went public in 2013, under the terms of the adjustment program agreed between Portugal, the European institutions (ECB and European Commission) and the IMF. The emphasis will be placed on the IPO process, but also on the company itself (its history, current situation and prospects for its new phase, as a publicly listed company). This piece of work aims to evaluate the different alternatives for the privatisation of the company along with the respective implications, as well as the outcome of the actual decision taken by the Portuguese Government. One key aspect of the case is also to understand the importance that the privatisation of the Royal Mail, which can be seen as a peer of the Portuguese company, in the unfolding of the process and in the choice of the privatisation model. The case intends to show how the British process influenced the subsequent option of the Portuguese entities to sell CTT through an IPO, instead of a trade sale. All in all, the overall objective of this case-study is to analyse CTT’s successful sale process, which created the first Portuguese company with 100% free-float. 3 On the last days of November 2013, Steven Bernstein was staring at the window of his office overlooking downtown Manhattan, not even noticing the intense rain that was pouring down. As senior manager at ABC Fund, a pension fund responsible for managing more than 800 million dollars, his thoughts were focused on a very important decision that ABC Fund would have to make in just a matter of days. The American pension fund was considering whether or not to invest in the upcoming Initial Public Offering of CTT- Correios de Portugal, the Government-owned Portuguese mail company. Is this investment opportunity in accordance with the risk profile of a pension fund? Is it a wise decision to acquire shares in a Portuguese company when the country is at the centre of the European Sovereign debt crisis, going through a very demanding economic adjustment program imposed by its bail-out creditors? Would the creation of Portugal's Postal Bank make CTT a sure bet today when its price does not fully reflect the future benefits from entering financial services? Those were some of the questions that were constantly in Mr. Bernstein’s mind over the last couple of days and he was struggling to find the answers…