As freguesias e as políticas educativas locais: as necessidades e as obrigações

Dissertação apresentada para obtenção do grau de Mestre em Ciências da Educação Área de especialização em Administração Escolar 2013

Modelos de supervisão/regulação bancária: enquadramento internacional e desenvolvimentos mais recentes

Mestrado em Contabilidade e Análise Financeira

Programa de aprendizagem ao longo da vida para estudantes seniores : bem-estar psicológico, qualidade de vida e a satisfação com a vida

Dissertação de Mestrado, Psicologia da Educação, especialidade de Contextos Comunitários, 11 de Março de 2016, Universidade dos Açores.

Equipamento de produção de água gelada para melhorar a eficácia do combate a incêndios florestais

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Design and evaluation of multi-band RF energy harvesting circuits and antennas for WSNs

Radio frequency (RF) energy harvesting is an emerging technology that will enable to drive the next generation of wireless sensor networks (WSNs) without the need of using batteries. In this paper, we present RF energy harvesting circuits specifically developed for GSM bands (900/1800) and a wearable dual-band antenna suitable for possible implementation within clothes for body worn applications. Besides, we address the development and experimental characterization of three different prototypes of a five-stage Dickson voltage multiplier (with match impedance circuit) responsible for harvesting the RF energy. Different printed circuit board (PCB) fabrication techniques to produce the prototypes result in different values of conversion efficiency. Therefore, we conclude that if the PCB fabrication is achieved by means of a rigorous control in the photo-positive method and chemical bath procedure applied to the PCB it allows for attaining better values for the conversion efficiency. All three prototypes (1, 2 and 3) can power supply the IRIS sensor node for RF received powers of -4 dBm, -6 dBm and -5 dBm, and conversion efficiencies of 20, 32 and 26%, respectively. © 2014 IEEE.

Linear and sliding-mode control design for matrix converter-based unified power flow controllers

This paper presents the design and compares the performance of linear, decoupled and direct power controllers (DPC) for three-phase matrix converters operating as unified power flow controllers (UPFC). A simplified steady-state model of the matrix converter-based UPFC fitted with a modified Venturini high-frequency pulse width modulator is first used to design the linear controllers for the transmission line active (P) and reactive (Q) powers. In order to minimize the resulting cross coupling between P and Q power controllers, decoupled linear controllers (DLC) are synthesized using inverse dynamics linearization. DPC are then developed using sliding-mode control techniques, in order to guarantee both robustness and decoupled control. The designed P and Q power controllers are compared using simulations and experimental results. Linear controllers show acceptable steady-state behaviour but still exhibit coupling between P and Q powers in transient operation. DLC are free from cross coupling but are parameter sensitive. Results obtained by DPC show decoupled power control with zero error tracking and faster responses with no overshoot and no steady-state error. All the designed controllers were implemented using the same digital signal processing hardware.

The K-Th derivatives of the immanant and the X-symmetric power of an operator

In recent papers, formulas are obtained for directional derivatives, of all orders, of the determinant, the permanent, the m-th compound map and the m-th induced power map. This paper generalizes these results for immanants and for other symmetric powers of a matrix.

The norm of the K- Th derivative of the X-symmetric power of an operator

In this paper, the exact value for the norm of directional derivatives, of all orders, for symmetric tensor powers of operators on finite dimensional vector spaces is presented. Using this result, an upper bound for the norm of all directional derivatives of immanants is obtained.

Periodic paths on nonautonomous graphs

We define nonautonomous graphs as a class of dynamic graphs in discrete time whose time-dependence consists in connecting or disconnecting edges. We study periodic paths in these graphs, and the associated zeta functions. Based on the analytic properties of these zeta functions we obtain explicit formulae for the number of n-periodic paths, as the sum of the nth powers of some specific algebraic numbers.

Pseudo-fractional ARMA modelling using a double Levinson recursion

IET Control Theory & Applications, Vol. 1, Nº 1

Controlo da fermentação do mosto e das condições ambientais de uma sala de lagares

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Avaliação do potencial eólico para geração de energia eléctrica

Trabalho Final de Mestrado para a obtenção do grau de Mestre em Engenharia Mecânica /Energia

Is there space for senior civil servants hybrid management models across political- administrative systems?

Comunicação apresentada na 17.ª conferência anual da NISPACee, realizada de 14 a 16 de Maio de 2009.

Rhapsody in fractional

This paper studies several topics related with the concept of “fractional” that are not directly related with Fractional Calculus, but can help the reader in pursuit new research directions. We introduce the concept of non-integer positional number systems, fractional sums, fractional powers of a square matrix, tolerant computing and FracSets, negative probabilities, fractional delay discrete-time linear systems, and fractional Fourier transform.

The most Portuguese village in Portugal: tradition in the age of its technical reproducibility

Ethnographic film is often associated with many European countries’ past as colonial powers and the way these countries used film to depict African, American and Asian territories and populations they once ruled. However, ethnographic film also has a European tradition of its own, closely interlaced with the history of ethnography and anthropology as autonomous sciences and with the desire of scholars to represent local, regional and national cultural identities. This paper presents a Portuguese attempt of this sort dating from 1938, when the authoritarian regime organized a national contest to determine which would be Portugal’s most “authentic” village – something other European countries also did. As part of this metonymic contribution to the construction of Portugal’s national identity as an agrarian utopia, a short documentary was shot, sponsored by the same official propaganda office that had organized the contest. In this film, the viewer’s gaze is made to coincide with the one of the national jury visiting the final selection of 12 villages and to whose benefit local scholars had organized all sorts of colourful peasant traditions hoping to cause the strongest impression. The film makes a strong case for the importance of ethnographic film as a relevant instance not only of the iteration of existing European national cultures, but also of the construction of so many of Europe’s national identities and traditions. Suffice to say that even today the village of “Monsanto”, which won the 1938 contest, is still referred to as “Portugal’s most Portuguese village”.