Design of passive SD modulator for ESP32

This thesis addresses the problem of voice recognition, by studying how to build a lowcost solution for data acquisition, presents the analysis, design implementation and simulation of a low-cost continuous-time(CT) passive sigma-delta modulator(SDM) with signal-to-noise-plus-distortion ratio(SNDR) > 86dB to increase fidelity in voice recognition applications. Employing passive RC integrators and a differential signal structure, the CT passive SDM is optimized to work as independently from a specific comparator module as possible, by decreasing the necessary gain of the comparator in the modulator gain. Nevertheless, the loop gain is restricted by the comparator’s noise, aggravated by the high attenuation of the passive RC integrators on the signal, causing low voltage swing at the comparator’s input. It is discussed the viability of utilizing a microprocessor (μP) as substitute of the comparator block in a CT passive SDM, specifically, the esp32. Due to hardware limitations and the high-frequency requirements of the CT passive SDM, it is proven this substitution is not viable. Along the course of the design implementation a comparison in the performance of three different simulation software is presented, these software being, the open-source LTspice VII, the open-source Ngspice and the private Cadence Virtuoso. As it was necessary to change simulation software at different stages in the design of the circuit

Liquidity rules in Basel III : a test on the largest portuguese banks

Mestrado em FinançasO principal objectivo da presente dissertação foi uma análise preliminar sobre os novos regulamentos provenientes do Basileia III, nomeadamente, uma análise inicial ao Liquidity Coverage Ratio e a sua aplicação prática assim como os seus benefícios na gestão do risco de liquidez nas instituições financeiras. Neste sentido, foram seleccionadas as 5 instituições financeiras, à data de 31 de Dezembro de 2012, que representavam a amostra mais relevante em termos de actividade no sector Português da banca comercial ("mercado bancário" Português). Recorrendo ao Liquidity Coverage Ratio obtido, foi possível observar que o "mercado bancário" português apresentou, inicialmente, um Liquidity Coverage Ratio acima do requerido pelo Basileia III (60%). O Liquidity Coverage Ratio obtido no "mercado bancário" Português foi de 102% em 2013. Num cenário simulado de stress, pode ser verificado que, o mínimo que a carteira de activos líquidos de alta qualidade no "mercado bancário" pode cair é de aproximadamente 59% do seu valor, à data de 31 de Dezembro de 2013, e ainda assim existem condições para cumprir com o mínimo requerido pelo Basileia III (60%). De acordo com todas as análises realizadas, foi possível concluir que o "mercado bancário" Português, tem capacidade para suportar, eficientemente, qualquer cenário de stress financeiro. Desta forma, o mercado detém uma quantidade suficiente de activos líquidos de alta qualidade, que podem fácil e rapidamente ser convertidos em dinheiro (nos sector privados) que suportem uma volatilidade de mercado significativa ou cenários de stress que durem mais de 30 dias.The main objective of the present dissertation was a preliminary analysis of the new regulatory package of Basel III, namely, a first analysis of the Liquidity Coverage Ratio computation, its practical application and its benefits for liquidity risk management in financial institutions. For this purposes, it was selected a sample of 5 Portuguese financial institutions which, as at 31 December 2012, represented the most relevant financial institutions with retail banking activities (Portuguese "banking market"). Considering the average Liquidity Coverage Ratio obtained it was possible to observe that the Portuguese "banking market" started to present a Liquidity Coverage Ratio clearly above the Basel III minimum requirement (60%). The Liquidity Coverage Ratio obtained by the Portuguese "banking market" insofar was 102% for 2013. In a simulated stress scenario, we were able to verify that the minimum which Portuguese "banking market" high quality liquidity assets stock could drop was approximately 59% of its value, at 31st of December 2013, and still maintain the conditions to fulfil the Basel III minimum requirement (60%). According to all the analysis performed, it was possible to conclude that the Portuguese "banking market" has the ability to efficiently sustain, any financial stress scenario. In this sense, holds sufficient stock of high quality liquidity assets that could be easily and immediately converted into cash (in private markets) in order to sustain a significant market volatility or stress scenarios lasting over 30 calendar days

A Systems Approach to Minimize Wasted Work in Blockchains

Blockchain systems and distributed ledgers are getting increasing attention since the release of Bitcoin. Everyday they make headlines in the news involving economists, scientists, and technologists. The technology invented by Satoshi Nakamoto gave to the world a quantum leap in the fields of distributed systems and digital currencies. Even so, there are still some problems regarding the architecture in most existing blockchain systems. One of the main challenges in these systems is the structure of the network topology and how peers disseminate messages between them, this leads to problems regarding the system scalability and the efficiency of the transaction and blocks propagation, wasting computational power, energy and network resources. In this work we propose a novel solution to tackle these limitations. We propose the design of membership and message dissemination protocols, based on the state-ofart, that will boost the efficiency of the overlay network that support the interactions between miners, reducing the number of exchanged messages and the used bandwidth. This solution also reduces the computational power and energy consumed across all nodes in the network, since the nodes avoid to process redundant network messages, and, becoming aware of mined blocks faster, avoid to perform computations over an outdated chain configuration

Ensino de Máquinas Elétricas: Uma Experiência Pedagógica com Técnicas de Aprendizagem Ativa

Poster apresentado no 2º Congresso Politécnico de Setúbal: 40 anos a construir o futuro, outubro 2019, Setúbal, PortugalN/

Personal learning environments: conceptions and practices

O conceito de ambiente pessoal de aprendizagem, comummente designado pela sigla «PLE» (Personal Learning Environments), depreende estratégias pedagógicas pouco exploradas no panorama educacional e a sua definição é ainda tácita. A juvenilidade deste tema e a sua proximidade aos fenómenos tecnológicos emergentes, como é o caso da Web 2.0 e das redes sociais, favoreceu o desenvolvimento de um estudo sobre estes ambientes em contexto de aprendizagem. Por estes motivos, o domínio teórico da investigação procurou estabelecer um sentido universal à sua definição e expor diversas conceções e práticas contextualizadas ao processo de ensino e aprendizagem. O estudo exploratório, em torno da utilização destes ambientes de aprendizagem, identificou tecnologias centradas no PLE com a procura de inovação nas pedagogias atuais. Para este propósito foram inquiridos profissionais de educação, observados ambientes e entrevistados especialistas reconhecidos pela comunidade científica. Conclui-se que o PLE pode estimular o desenvolvimento de instrumentos de auto-orientação e dá preferência a estratégias de aprendizagem descentralizadas das instituições de educação. Ao mesmo tempo que promove competências como a autonomia e a organização individual dos aprendizes exige novas competências nos programas do ensino. A complexidade decorrente da integração destas competências em contextos de aprendizagem formais é enfatizada nos resultados apurados que revelam que as mudanças consubstanciadas na adoção dos PLE carecem de novas atitudes por parte dos vários intervenientes do sistema de ensino.The concept of Personal Learning Environment (PLE), still infers teaching strategies that have been poorly explored within the educational panorama and its definition is still tacit. The youthfulness of this topic and its proximity to the emerging technological phenomena favored the development of a study of these environments in the context of learning. For these reasons, the theoretical domain of research sought to establish a universal sense of its definition and to explain various conceptions and practices within the context of the teaching and learning process. The exploratory study focusing on the use of these learning environments identified technologies geared towards PLE in the search for innovation in current pedagogies. To this avail, education professionals were questioned; a personal learning environment was observed and experts recognized by the scientific community were interviewed. We conclude that the PLE can stimulate the development of instruments for self-orientation and gives preference to decentralized (from educational institutions) learning strategies. At the same time it promotes skills such as autonomy and individual organization and demands new skills from education programs. The complexity resulting from the integration of these skills in formal learning contexts is emphasized in the reported results and shows that the changes embodied in the adoption of the PLE require new attitudes by the various stakeholders in the education system.El concepto de entorno personal de aprendizaje, comúnmente designado por las siglas “PLE” (Personal Learning Environments),desprende estrategias de enseñanza que han sido poco explorados en el panorama educativo y su definición es todavía tácita. La juventud de este tema y su proximidad a los fenómenos tecnológicos emergentes, como es el caso de la Web 2.0 y de las redes sociales, favoreció el desarrollo de un estudio sobre estos entornos en el contexto del aprendizaje. Por estas razones, el dominio teórico de la investigación trató de establecer un sentido universal a su definición y explicar diversos conceptos y prácticas en el contexto del proceso de enseñanza y aprendizaje. El estudio exploratorio sobre el uso de estos entornos de aprendizaje, identificó tecnologías orientadas al PLE en la búsqueda de la innovación en las pedagogías actuales. Para este propósito fueron encuestados los profesionales de la educación, observados en un ambiente de aprendizaje personal y entrevistados por expertos reconocidos por la comunidad científica. Hemos llegado a la conclusión de que el PLE puede estimular el desarrollo de instrumentos de auto-orientación y da preferencia a la descentralización estrategias de aprendizaje (de instituciones educativas). Al mismo tiempo que promueve habilidades tales como la autonomía y organización particular y exige nuevas habilidades de los programas de educación. La complejidad resultante de la integración de estos conocimientos en contextos de aprendizaje formal se destaca en el informe de los resultados y demuestra que los cambios incorporados en la aprobación del PLE exige nuevas actitudes de los distintos actores interesados en el sistema educativo

Teachers and Technology: A Complicated Relationship Pedro Brás, Guilhermina Lobato Miranda and João Marôco

Although technology is present in most classrooms and many countries have made strong recommendations for ICT integration in schools and teachers’ practices, a great number of teachers do not use ICT in their educational activities. Research has provided theories and models that explain the consistency of the relationship between attitudes and behavior. These theories converge to identify common aspects that foster technology integration.We now propose an “ICT Skills Towards Technology Use” (ISTTU) model to evaluate the impact of “ICT Knowledge” over “Intention to Use ICT” (IUICT). Based on previously validated questionnaires, we have developed a questionnaire that was applied to a sample of teachers from the vocational stream of secondary education in Portugal. The data was tested and evaluated using Structural Equation Modeling techniques and we concluded that “ICT Knowledge” is a good predictor of the “IUICT” and that “teaching area” has an impact on “Intention to Use ICT”. We also concluded that “gender” and “Learning through ICT” have no significant impact on IUICT. The ISTTU model shows that fostering the development of ICT skills (increasing “ICT Knowledge”) will develop the “intention to use technologies with students”

Cooperative learning in higher education: Training in social skills of group work

El aprendizaje cooperativo se presenta como una metodología idónea para abordar el desarrollo de la competencia de trabajo en equipo dentro del proceso enseñanza y aprendizaje universitarios. La experiencia se desarrolló en seis grupos distintos que suman un total de 185 estudiantes de distintos centros y titulaciones de la Universidad del País Vasco (UPV/EHU). Se analizan los resultados obtenidos por esta experiencia mediante un cuestionario que recoge las principales competencias del trabajo en equipo. El análisis de las dimensiones del cuestionario muestra una estructura con dos dimensiones: a. ‘Saber ser/estar’, b. ‘Saber Estar’. Esta estructura es coherente conceptualmente y consistente empíricamente. Asimismo, los resultados obtenidos muestran diferencias apreciables entre ambas dimensiones por lo que cabe afirmar el poder discriminativo de esta estructura dimensional.Cooperative Learning seems to be the right methodology to tackle the development of the teamwork competence inside the process of teaching-learning at the University. The experience was developed in six different groups which add up as 185 students of different faculties and schools of the University of the Basque Country (UPV/EHU). The outcome of that experience was analyzed by means of a questionnaire which gathers the main competences of teamwork. The analysis of the dimensions of the questionnaire shows a structure with two dimensions: a. ‘Interpersonal competences’, b. ‘Instrumental competences’. This structure is conceptually coherent and empirically con sistent. Results also show significant differences between both dimensions which may be stating the discriminative power of this dimensional structure.peerReviewe

Direitos autorais e cibercultura

Resumo: Com a evolução dos meios de comunicação e o desenvolvimento da Internet, bens culturais passaram a ser inseridos no espaço virtual. Com a ascensão da prática do compartilhamento de arquivos na Internet e as constantes ofensivas por parte da indústria do conteúdo contra a mesma, é necessário buscar uma análise crítica do atual sistema de direitos autorais e sua tutela acerca dessas novas relações dentro de uma sociedade informatizad

Implementação do Kanban de produção

Estágio realizado na Simoldes PlásticosRelatório do Estágio Curricular da LGEI 2004/200