168 research outputs found

    Low-cost digital system for power quality monitoring

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    This paper describes the development of a low-cost digital system used for power quality monitoring. The system uses voltage and current Hall sensors, a standard data acquisition board, and has its processing system based on LabVIEWTM, running on a regular Personal Computer. Several parame- ters related to power quality can be analyzed through 4 different applications: “Scope and THD”, “Events PQ”, “Classical Values” and “p-q Theory”. The acquired information can be visualized in ta- bles and/or in charts. It is also possible to generate reports in HTML format. In this format, the re- ports can be sent directly to a printer, can be embedded in other software applications, or can be accessed through Internet, using a web browser.Este artículo describe el desarrollo de un sistema digital de bajo coste utilizado para la monitoriza-ción de la calidad de energía eléctrica. El sistema está compuesto por sensores de efecto Hall de tensión y corriente, una tarjeta de adquisición de datos estándar y un ordenador personal vulgar. Las aplicaciones de software han sido desarrolladas en un entorno de programación gráfica (Lab-VIEW™). Varios parámetros, relacionados con la calidad de energía eléctrica y gerencia de la ener-gía, pueden ser analizados por 4 diferentes aplicaciones: “Scope and THD”, “Events PQ”, “Classical Values” y “p-q Theory”. La información capturada pude ser visualizada en tablas y/o gráficos. Tam-bién es posible generar informes en formato HTML y Word. En formato HTML, los informes pueden ser enviados directamente a una impresora, pueden ser usados en otras aplicaciones de Windows o pueden se consultados por Internet utilizando un navegador Web.Fundação para a Ciência e a Tecnologia (FCT

    Design of the ISePorto robocup Middle-Size League Robotic Soccer Team: Control, Localisation and Coordination

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    Proceedings of the 10th Mediterranean Conference on Control and Automation - MED2002 Lisbon, Portugal, July 9-12, 2002This paper describes the design and implementation status of the ISePorto robotic football team for participation in Robocup Middle Size League (F2000). The objectives guiding the project were the applications and research in hybrid control and coordination systems. The system has also an educational support role. A special attention is made to the custom design to allow the execution of complex manoeuvres and team coordinated behaviours. The robot has different pass, shot, and manoeuvre capabilities providing high level tactical and strategic planing and coordination. The current team status is also covered

    Problem-based learning in a flipped classroom: A case study for active learning in legal education in international law

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    Higher education in law should develop students’ skills such as working collaboratively, communicating, and influencing others through critical legal reasoning. Traditional legal education is partially based on active learning methods, but problem-based learning (PBL) is still relatively rare, with a comparatively smaller number of field applications reported in available literature, and no reports of its use of in legal education in Portugal. This paper describes the application of the problem-based learning method to an Erasmus class of International Public Law in a Portuguese university, during an academic semester. The method was applied to half of the classes, with the remaining half being taught using traditional methods. Students’ perceptions and preferences for the different methods were assessed through surveys. In general, our results offer novel insights into the effectiveness of PBL, suggesting that student perceptions of the PBL method depend on their social skills, previous knowledge of the topics, and personal preference. Considering experiences from previous years, the teacher’s assessment is that using PBL methods allowed for feedback and closer follow-up on the students’ progress and created the opportunity for the development of relevant skills, which would otherwise be excluded from the classroom. These results, as well as limitations, are discussed.info:eu-repo/semantics/publishedVersio

    New insights into adaptation and population structure of cork oak using genotyping by sequencing

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    Species respond to global climatic changes in a local context. Understanding this process, including its speed and intensity, is paramount due to the pace at which such changes are currently occurring. Tree species are particularly interesting to study in this regard due to their long generation times, sedentarism, and ecological and economic importance. Quercus suber L. is an evergreen forest tree species of the Fagaceae family with an essentially Western Mediterranean distribution. Despite frequent assessments of the species' evolutionary history, large-scale genetic studies have mostly relied on plastidial markers, whereas nuclear markers have been used on studies with locally focused sampling strategies. In this work, "Genotyping by sequencing" is used to derive 1,996 single nucleotide polymorphism markers to assess the species' evolutionary history from a nuclear DNA perspective, gain insights into how local adaptation is shaping the species' genetic background, and to forecast how Q. suber may respond to global climatic changes from a genetic perspective. Results reveal (a) an essentially unstructured species, where (b) a balance between gene flow and local adaptation keeps the species' gene pool somewhat homogeneous across its distribution, but still allowing (c) variation clines for the individuals to cope with local conditions. "Risk of Non-Adaptedness" (RONA) analyses suggest that for the considered variables and most sampled locations, (d) the cork oak should not require large shifts in allele frequencies to survive the predicted climatic changes. Future directions include integrating these results with ecological niche modeling perspectives, improving the RONA methodology, and expanding its use to other species. With the implementation presented in this work, the RONA can now also be easily assessed for other organisms.info:eu-repo/semantics/publishedVersio

    Ownserver: sistema doméstico de prestação de serviços cloud

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    Neste trabalho foi considerada a possibilidade de incorporar serviços remotos, normalmente associados a serviços web e cloud computing, numa solução local que centralizasse os vários serviços num único sistema e permitisse aos seus utilizadores consumir e configurar os mesmos, quer a partir da rede local, quer remotamente a partir da Internet. Desta forma seria possível conciliar o acesso a partir de qualquer local com internet, característico nas clouds, com a simplicidade de concentrar num só sistema vários serviços que são por norma oferecidos por entidades distintas e ainda permitir aos seus utilizadores o controlo e configuração sobre os mesmos. De forma a validar que este conceito é viável, prático e funcional, foram implementadas duas componentes. Um cliente que corre nos dispositivos dos utilizadores e que proporciona a interface para consumir os serviços disponíveis e um servidor que irá conter e prestar esses serviços aos clientes. Estes serviços incluem lista de contactos, mensagens instantâneas, salas de conversação, transferência de ficheiros, chamadas e conferências de voz e vídeo, pastas remotas, pastas sincronizadas, backups, pastas partilhadas, VoD (Video-on Demand) e AoD (Audio-on Demand). Para o desenvolvimento do cliente e do servidor foi utilizada a framework Qt que recorre à linguagem de programação C++ e ao conjunto de bibliotecas que possui, para o desenvolvimento de aplicações multiplataforma. Para as comunicações entre clientes e servidor, foi utilizado o protocolo XMPP (Extensible Messaging and Presence Protocol), pela forma da biblioteca qxmpp e do servidor XMPP ejabberd. Pelo facto de conter um conjunto de centenas de extensões atualmente ativas que auferem funcionalidades como salas de conversação, transferências de ficheiros e até estabelecer sessões multimédia, graças à sua flexibilidade permitiu ainda a criação de extensões personalizada necessárias para algumas funcionalidades que se pretendeu implementar. Foi ainda utilizado no servidor a framework ffmpeg para suportar algumas funcionalidades multimédia. Após a implementação do cliente para Windows e Linux, e de implementar o servidor em Linux foi realizado um conjunto de testes funcionais para perceber se as funcionalidades e seus mecanismos funcionam corretamente. No caso onde a análise da performance e do consumo de recursos era importante, foram realizados testes de performance e testes de carga

    Master's in autonomous systems: an overview of the robotics curriculum and outcomes at ISEP, Portugal

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    Robotics research in Portugal is increasing every year, but few students embrace it as one of their first choices for study. Until recently, job offers for engineers were plentiful, and those looking for a degree in science and technology would avoid areas considered to be demanding, like robotics. At the undergraduate level, robotics programs are still competing for a place in the classical engineering graduate curricula. Innovative and dynamic Master’s programs may offer the solution to this gap. The Master’s degree in autonomous systems at the Instituto Superior de Engenharia do Porto (ISEP), Porto, Portugal, was designed to provide a solid training in robotics and has been showing interesting results, mainly due to differences in course structure and the context in which students are welcomed to study and wor

    Virtual Reality And The Future Of Construction

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    Introduction: Despite the recent trends in technology, construction projects are becoming increasingly challenging, which, in the result, brings in more complex and dynamic construction environments. In fact, traditional management and monitoring methods are currently unable to keep up with the industry's quick development, leading to several problems in task efficiency and transfer of information between stakeholders. As a result, the Architecture Engineering Construction and Operations (AECO) sector is making use of the digitalization in order to improve project management, assist trade-crews and achieve a more proficient working environment. The adoption of Building Information Modelling (BIM) embodies a paradigm shift from the traditional approaches towards a collaborative and integrated working process. Though BIM is improving the aforesaid issues, not every construction entity can easily adapt and use it successfully. Therefore, supportive tools to assist BIM in achieving its full potential are in high demand. Objectives: The current research objective is to provide a review of previous works in the field of BIM-based Virtual Reality (VR), in order to establish a clear view of this research field. This work provides the primary data on such goals. Methodology: In order to conduct the research, the PRISMA Statement strategy was used. The selected primary keywords were "construction", "virtual reality" and "building information modelling" and their variants. The research was carried out in the main engineering databases and journals, being Scopus, Science Direct and IEEE Xplore some examples. Results: After the identification of 2,950 records, exclusion criteria were applied: year of publication, type of document, type of source and deduplication. The titles and abstracts of the publications were screened in order to determine the scope of the papers, leaving for full-text analysis just 75 studies. After going through the eligibility criteria, only 14 papers remained. Using the snowballing technique, two more papers were added to the study, resulting in 16 included papers. Most of the papers focused on the Construction Design, Construction Management, and Construction Safety fields, being "design" the most occurring construction stage. The highlighted target groups for the VR interfaces were Engineers, Architects and Workers. Most system architectures comprise, at least, three layers regarding a BIM software tool, a visual enhancement module and a game engine to provide the virtual environment and interaction functionalities. However, some studies referred to a fourth layer (database). Conclusions: The BIM-VR relation addressed in the articles was mainly focused on the model's geometric information since BIM provides an accurate display of building geometry. Most VR interfaces do not possess a database component to provide access to BIM parametric information, leading to the conclusion that BIM is not achieving its full potential with VR tools
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