How short and light can a simple pendulum be for classroom use?

We compare the period of oscillation of an ideal simple pendulum with the period of a more 'real' pendulum constituted of a rigid sphere and a rigid slender rod. We determine the relative error in the calculation of the local acceleration of gravity if the period of the ideal pendulum is use?d instead of the period of this real pendulum. © 2014 IOP Publishing Ltd..

How market power affects the behaviour of a pumped storage hydro unit in the day-ahead electricity market?

The integration of large amounts of wind energy in power systems raises important operation issues such as the balance between power demand and generation. The pumped storage hydro (PSH) units are seen as one solution for this issue, avoiding the need for wind power curtailments. However, the behavior of a PSH unit might differ considerably when it operates in a liberalized market with some degree of market power. In this regard, a new approach for the optimal daily scheduling of a PSH unit in the day-ahead electricity market was developed and presented in this paper, in which the market power is modeled by a residual inverse demand function with a variable elasticity. The results obtained show that increasing degrees of market power of the PSH unit correspond to decreasing levels of storage and, therefore, the capacity to integrate wind power is considerably reduced under these circumstances.

How human schematization and systematic errors take effect on sketch map formalizations

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

How to Measure the Deterrence Effects of Merger Policy: Frequency or Composition?

We show that the number of merger proposals (frequency-based deterrence) is a more appropriate indicator of underlying changes in merger policy than the relative anti-competitiveness of merger proposals (composition-based deterrence). This has strong implications for the empirical analysis of the deterrence effects of merger policy enforcement, and potential implications regarding how to reduce anti-competitive merger proposals.

How remote labs impact on course outcomes: various practices using VISIR

As technology is increasingly being seen as a facilitator to learning, open remote laboratories are increasingly available and in widespread use around the world. They provide some advantages over traditional hands-on labs or simulations. This paper presents the results of integrating the open remote laboratory VISIR into several courses, in various contexts and using various methodologies. These integrations, all related to higher education engineering, were designed by teachers with different perspectives to achieve a range of learning outcomes. The degree to which these VISIR-related outcomes were accomplished is discussed. The results reflect the levels of student engagement and learning and of teacher involvement. From the analysis, a connection between these two aspects was traced, although only related to the user profiles. VISIR is shown to be always of benefit for more motivated students, but this benefit can be maximized under particular conditions and characteristics.

How to feel "in love" with Math - a MOOC experience

In the past few years we have witnessed the fast development of distance learning tools such as Open Educational Resources (OER) and Massive Open Online Courses (MOOCs). This paper presents the “Mathematics without STRESS” MOOC Project, which is a cooperation between four schools from the Polytechnic Institute of Oporto (IPP). The concepts of MOOC and their quickly growing popularity are presented and complemented by a discussion of some MOOC definitions. The process of the project development is demonstrated by focusing on used MOOC structure, as well as the several types of course materials produced. At last, is presented a short discussion about problems and challenges met throughout the project. It is also our goal to contribute for a change in the way as teaching and learning Mathematics is seen and practiced nowadays.

How to reduce energy consumption on pultrusion

The global warming due to high CO2 emission in the last years has made energy saving a global problem nowadays. However, manufacturing processes such as pultrusion necessarily needs heat for curing the resin. Then, the only option available is to apply all efforts to make the process even more efficient. Different heating systems have been used on pultrusion, however, the most widely used are the planar resistances. The main objective of this study is to develop another heating system and compares it with the former one. Thermography was used in spite of define the temperature profile along the die. FEA (finite element analysis) allows to understand how many energy is spend with the initial heating system. After this first approach, changes were done on the die in order to test the new heating system and to check possible quality problems on the product. Thus, this work allows to conclude that with the new heating system a significant reduction in the setup time is now possible and an energy reduction of about 57% was achieved.

A improvisação como ferramenta pedagógica no ensino vocacional de piano

Resumo I - A frequência do Estágio do Ensino Especializado proporcionou uma oportunidade de observar o ensino de piano numa das escolas mais importantes do ensino da música em Portugal, acompanhando alunos do Curso Básico e do Curso Secundário, que frequentaram a Escola de Música do Conservatório Nacional no regime integrado. O processo de observação de aulas que decorreu deste estágio possibilitou-nos assistir às aulas de piano de uma professora experiente, permitindo a observação de metodologias consolidadas e assistir de perto à forma como estas são postas em prática. Por outro lado, através da leccionação de aulas observadas, foi dada a oportunidade de testar e reflectir sobre o próprio desempenho docente, procurando estratégias e ferramentas pedagógicas que possam vir a acrescentar qualidade à prática pedagógica. O ensino especializado da música em Portugal tem experimentado mudanças importantes, o que leva a que haja uma adaptação das escolas às mudanças, continuando a leccionar um ensino de qualidade, que se quer cada vez mais eficaz, inovador, e com professores cada vez melhor fundamentados e preparados.

SIN 319 AND VOSKR 27 AND THE TRIODION CYCLE IN THE LITURGICAL PRAXIS IN RUSSIA DURING THE STUDITE PERIOD

A Thesis Presented to the Faculty of Social and Human Science of the Universidade Nova de Lisboa in Candidacy for the Degree of Doctor of Philosophy in Musicology

How Complex, Probable, and Predictable is Genetically Driven Red Queen Chaos?

Coevolution between two antagonistic species has been widely studied theoretically for both ecologically- and genetically-driven Red Queen dynamics. A typical outcome of these systems is an oscillatory behavior causing an endless series of one species adaptation and others counter-adaptation. More recently, a mathematical model combining a three-species food chain system with an adaptive dynamics approach revealed genetically driven chaotic Red Queen coevolution. In the present article, we analyze this mathematical model mainly focusing on the impact of species rates of evolution (mutation rates) in the dynamics. Firstly, we analytically proof the boundedness of the trajectories of the chaotic attractor. The complexity of the coupling between the dynamical variables is quantified using observability indices. By using symbolic dynamics theory, we quantify the complexity of genetically driven Red Queen chaos computing the topological entropy of existing one-dimensional iterated maps using Markov partitions. Co-dimensional two bifurcation diagrams are also built from the period ordering of the orbits of the maps. Then, we study the predictability of the Red Queen chaos, found in narrow regions of mutation rates. To extend the previous analyses, we also computed the likeliness of finding chaos in a given region of the parameter space varying other model parameters simultaneously. Such analyses allowed us to compute a mean predictability measure for the system in the explored region of the parameter space. We found that genetically driven Red Queen chaos, although being restricted to small regions of the analyzed parameter space, might be highly unpredictable.

On the analytical solutions of the Hindmarsh-Rose neuronal model

In this article we analytically solve the Hindmarsh-Rose model (Proc R Soc Lond B221:87-102, 1984) by means of a technique developed for strongly nonlinear problems-the step homotopy analysis method. This analytical algorithm, based on a modification of the standard homotopy analysis method, allows us to obtain a one-parameter family of explicit series solutions for the studied neuronal model. The Hindmarsh-Rose system represents a paradigmatic example of models developed to qualitatively reproduce the electrical activity of cell membranes. By using the homotopy solutions, we investigate the dynamical effect of two chosen biologically meaningful bifurcation parameters: the injected current I and the parameter r, representing the ratio of time scales between spiking (fast dynamics) and resting (slow dynamics). The auxiliary parameter involved in the analytical method provides us with an elegant way to ensure convergent series solutions of the neuronal model. Our analytical results are found to be in excellent agreement with the numerical simulations.

How can Public Administrations handle the societal crisis?

Comunicação apresentada na Universidade de Wroclow.

How are top officials hybrid management models present across political-administrative systems?

Comunicação apresentada na 4th Annual ICPA - International Conference on Public Administration "Building bridges to the future: leadership and collaboration in public administration", na Universidade de Minnesota nos Estados Unidos, de 24 a 26 de setembro de 2008

Gender inequities in portuguese state administration: how expressive feminization and facilitating laws are not enough to guarantee effective gender equity at public work

Comunicação apresentada na 69th ASPA Anual Conference, em Dalas, Texas de 7 a 11 de março de 2008

How to link organizational competences in public organizations?

Comunicação apresentada na 17ª Conferência Anual da Network of Intitutes and Schools of Public Administration (NISPA) em Birdua, Montenegro de 14 a 16 dem Maio de 2009.