Systemic intervention for computer-supported collaborative learning

This paper presents a systemic intervention approach as a means to overcome the methodological challenges involved in research into computer-supported collaborative learning applied to the promotion of mathematical problem-solving (CSCL-MPS) skills in schools. These challenges include how to develop an integrated analysis of several aspects of the learning process; and how to reflect on learning purposes, the context of application and participants' identities. The focus of systemic intervention is on processes for thinking through whose views and what issues and values should be considered pertinent in an analysis. Systemic intervention also advocates mixing methods from different traditions to address the purposes of multiple stakeholders. Consequently, a design for CSCL-MPS research is presented that includes several methods. This methodological design is used to analyse and reflect upon both a CSCL-MPS project with Colombian schools, and the identities of the participants in that project

Frameworks for Protocol Implementation

This paper reports on the development of a catalogue of frameworks for protocol implementation. Frameworks are software structures developed for a specific application domain, which can be re-used in the implementation of various different concrete systems in this domain. By using frameworks we aim at increasing the effectiveness of the protocol implementation process. We assume that whenever protocols are directly implemented from their specifications one may be able to increase the correctness and the speed of the implementation process, and the maintainability of the resulting system. We argue that frameworks should match the concepts underlying the techniques used for specifying protocols. Consequently, we couple the development of frameworks for protocol implementation to the investigation of the different alternative design models for protocol specification. This paper presents the approach we have been using to develop frameworks, and illustrates this approach with an example of framework

Towards an Architecture for Semiautonomous Robot Telecontrol Systems.

The design and development of a computational system to support robot–operator collaboration is a challenging task, not only because of the overall system complexity, but furthermore because of the involvement of different technical and scientific disciplines, namely, Software Engineering, Psychology and Artificial Intelligence, among others. In our opinion the approach generally used to face this type of project is based on system architectures inherited from the development of autonomous robots and therefore fails to incorporate explicitly the role of the operator, i.e. these architectures lack a view that help the operator to see him/herself as an integral part of the system. The goal of this paper is to provide a human-centered paradigm that makes it possible to create this kind of view of the system architecture. This architectural description includes the definition of the role of operator and autonomous behaviour of the robot, it identifies the shared knowledge, and it helps the operator to see the robot as an intentional being as himself/herself

The Expenditure Composition Hypothesis: Empirical Evidence and Implications for Monetary Policy.

Leão (2005) has recently proposed a new explanation for the short run variability of the velocity of money based on the changes in the composition of the expenditure that occur along the business cycle. This paper presents further empirical evidence in favour of Leão’s Expenditure Composition Hypothesis, and draws new implications of this hypothesis for monetary policy. We use a VAR model to analyze the determinants of the velocity of both M1 and M3 in the USA. The main conclusion is that increases in the weight of investment and durable consumption in total expenditure raise the velocity of both narrow and broad money. This is in line with the Expenditure Composition Hypothesis. Furthermore, we draw a new implication of this hypothesis for monetary policy. The more a central bank’s decisions on the interest rate respond to money growth, the more volatile economic growth will be. In other words, a monetary policy strategy - like that of the ECB – which puts emphasis on money growth is de-stabilizing.Velocity of money; monetary policy; business cycle.

Webquest y cine en la historia contemporánea : una experiencia de investigación-acción curricular en bachillerato

Las TIC representan una oportunidad para la integración en la enseñanza de estrategias de aprendizaje colaborativo, más activas, que sitúen al estudiante en el centro de su proceso de adquisición de conocimiento. No obstante, la posibilidad de un cambio real de paradigma no es automático ni fácil, y exige por parte de los docentes la identificación, el análisis y la superación de resistencias y dificultades. En este sentido, presentamos una experiencia propia de investigación-acción que ha recurrido a la Webquest como método para la mejora en la didáctica de la historia desde el empleo del cine como recurso.The ICTs represent an opportunity to incorporate more active collaborative learning strategies in the teaching practise, which can put the students in the center of their own process of knowledge acquisition. However, the possibility of a real change in the paradigm is not something easy or automatic, and teachers are forced to identify, analyse and overcome difficulties and reluctances. In that respect, we introduce here our own action research experience which has made use of Webquests as a method to improve History Methodology using cinema as a resource

“Narrative Beginnings and Lived Experiences in (Re) Shaping Stories to Live by: Embracing Multicultural Worlds through Narrative Inquiry.”

This thesis explores, through narrative inquiry methodology, the understanding about identity making when entering and living in a new world. More specifically, this thesis focuses on understanding, through narrative inquiry, how immigrants that chose Canada as a place to live and compose a new storied life, (re)shape their lives, their stories to live by, across multicultural landscapes. Initially driven by a narrative beginnings context, I engage in an autobiographical narrative, inquiring into my own stories as an immigrant from Brazil, embedded on understanding who we are and who we are becoming, when (re)shaping lives in motion; lives in the context of the multiplicity of worlds and identities. In addition, through the voices of David and Sam (participants of this research), and more specifically, through excerpts (transcripts) from the interviews with David and Sam, this thesis connects the sense of being an immigrant, embedded in a multicultural world, with how we (re)shape our stories to live by, as we compose lived stories in a new place. Within this perspective, this thesis demonstrates, inspired by the voices of David and Sam, how that at the same time we immigrants, paradoxically, try to keep our identities and to maintain our culture within a plurality of worlds and a plurality of lived experiences, we, can shift our identities in relation to the sense of living and belonging to a place. Lastly, this thesis also stresses the importance and the role of the community-based organizations that support newcomers, immigrants, and refugees. Precisely, through the voices of David and Sam, this thesis demonstrates how the support and some programs offered by community-based organizations affect and shape the context of identity making when living in a new world composing new stories to live by. In the discussion, I argue that embracing multicultural worlds through narrative inquiry can explore the understanding of identity making, (re)shaping ourselves, interwoven with being at ease in a ‘new world’ and the sense of happiness and openness to new cultures and stories. In addition, in the discussion, I claim about the importance and the intersection of the necessity of community-based organizations for newcomers in (re)shaping our stories to live by

Tourism in Azores Islands: Persistence in the Monthly Arrivals

This study analyses the persistence in the international monthly arrivals to the Azores Islands using a model based on fractional integration and seasonal autoregressions. The estimated fractional differencing parameter gives an indication of the long run evolution of the series. We use both aggregate data and disaggregate monthly data by location of origin and island destination. The results show that the aggregate series corresponding to the total number of arrivals is a nonstationary I(d) process with d above 1, and the most persistent ones are those travelling to Säo Miguel, especially from Holland, Finland, Norway, Germany, Denmark and the UK.Monthly arrivals; Seasonal fractional integration; Persistence; Azores Islands.

Smart power conditioners for electric railway power grids

Programa doutoral em Engenharia Eletrónica e de Computadores (especialidade de Eletrónica de Potência e Energia)Railway transport presents itself as one of the greatest economic and social drivers of several nations in the world. Furthermore, it is considered the safest means of land transport, with the electric rail system being efficient and environmentally friendly. However, for the inclusion of more and larger electric locomotives, it is necessary to increase the capacity of the railway supply systems. This doctoral thesis intends to contribute to the development of power electronics solutions capable of increasing the capacity of railway supply systems. As such, a power electronics converter connected in a neutral section located between two traction power substations (TPS) is proposed. The proposed algorithm makes it possible to dynamically balance the average active powers of the two substations, mitigating overload problems. In the event of deceleration or braking of a locomotive on one side, it is possible to use the energy from this regenerative braking to assist another locomotive on the other side of the neutral section. Moreover, the proposed solution still presents the interface with a photovoltaic solar system and an energy storage system. In this way, it is possible to minimize energy dependence on the power grid, as well as to include renewable energy sources. The storage system also makes it possible to store surplus production or energy from regenerative braking for later use. The proposed solution is validated with the help of computer simulations considering a real implementation scale. The simulation model is based on cascaded multilevel modular converters, with each submodule also featuring solid-state transformers. Considering a reduced-scale prototype developed in the laboratory, computer simulations of the prototype are also presented and discussed. The document also presents a chapter that portrays all the steps taken for the implementation of the reduced-scale sectioning post-Rail Power Conditioner (sp-RPC) laboratory prototype. Once its implementation was completed, its experimental validation was carried out, proving the correct functioning of the system based on the proposed algorithm.O transporte ferroviário apresenta-se como um dos maiores impulsionadores económicos e sociais de várias nações do mundo. Para além disso, é considerado como o meio de transporte terrestre mais seguro, sendo o sistema ferroviário elétrico eficiente e amigo do ambiente. Contudo, para a inclusão de mais e maiores locomotivas elétricas é necessário aumentar a capacidade dos sistemas de alimentação ferroviários. Esta tese de doutoramento pretende contribuir com o desenvolvimento de soluções de eletrónica de potência capazes de aumentar a capacidade dos sistemas de alimentação ferroviários. Como tal, é proposto um conversor de eletrónica de potência conectado numa secção neutra que se encontra entre duas subestações de tração de energia. A algoritmia proposta permite equilibrar as potências ativas médias das duas subestações de forma dinâmica, mitigando os problemas de sobrecarga. Na ocorrência de uma desaceleração ou travagem de uma locomotiva num dos lados, é possível utilizar a energia proveniente desta travagem regenerativa para o auxílio de marcha de outra locomotiva existente no outro lado da secção neutra. Não obstante, a solução proposta apresenta ainda a interface com um sistema solar fotovoltaico e um sistema de armazenamento de energia. Desta forma, é possível minimizar a dependência energética da rede elétrica, bem como incluir fontes de energia renovável. O sistema de armazenamento permite ainda armazenar o excedente de produção ou a energia proveniente de uma travagem regenerativa para posterior utilização. O conceito proposto é estudado com auxílio de simulações computacionais considerando uma escala de implementação real. O modelo de simulação é baseado em conversores modulares multinível em cascata, sendo que cada sub-módulo apresenta ainda transformadores de estado sólido. Considerando um protótipo de pequena escala desenvolvido em laboratório, simulações computacionais do protótipo são igualmente apresentadas e validadas. O documento apresenta ainda um capítulo que retrata todos os passos realizados para a implementação do protótipo laboratorial do sectioning post-Rail Power Conditioner (sp-RPC) de pequena escala. Uma vez finalizada a sua implementação, procedeu-se à sua validação experimental, comprovando o correto funcionamento do sistema com base na algoritmia proposta.This work has been supported by FCT — Fundação para a Ciência e Tecnologia, within the R&D Units Project Scope UIDB/00319/2020. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018, granted by the Portuguese FCT foundation