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Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-05-17T19:08:31Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Roberto_Mariano.pdf: 2556716 bytes, checksum: bc04f16516e0632af829880453a025c6 (MD5) / Made available in DSpace on 2017-05-17T19:08:31Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Roberto_Mariano.pdf: 2556716 bytes, checksum: bc04f16516e0632af829880453a025c6 (MD5) Previous issue date: 2015-02-24 / CAPES / Esta pesquisa tem por objetivo analisar a aprendizagem colaborativa suportada por computador no contexto da formação do professor de matemática quanto ao uso de modelagem para o ensino e aprendizagem de funções. A pesquisa fundamenta-se na Aprendizagem Colaborativa com Suporte Computacional (CSCL), Caracterização das Funções e Modelagem Matemática. A metodologia de investigação conta com as fases de elaboração do ambiente virtual CSCL para propiciar: discussão das dificuldades de aprendizagem das funções, discussão e elaboração de simuladores utilizando o software Modellus, exploração da modelagem como metodologia de ensino e aprendizagem, de forma colaborativa. A situação foi estruturada tendo como momento inicial uma instrumentalização dos softwares que suportam a comunicação e interação, além do software de modelagem que permite a exploração de situações envolvendo as funções afim e quadrática, em sintonia com as discussões das teorias da CSCL. O estudo analisa o trabalho colaborativo desenvolvido por 3 grupos de licenciandos em Matemática. Os dados revelam que o grupo menor conseguiu colaborar com mais facilidade que os grupos maiores. Os dados mostram também que as discussões acerca das dificuldades dos estudantes foi onde houve maior colaboração. Além disso, o script elaborado não conseguiu direcionar os participantes sozinhos durante a atividade, precisando sempre de uma intervenção do mediador. Também foram percebidos entraves do ambiente que mostraram a necessidade da montagem de outro espaço, que pudesse oferecer recursos que facilitem a comunicação entre os participantes da sessão. / This research aims to analyze collaborative learning supported by computer in the mathematics teachers trainning course in the use of modeling for teaching and learning functions. The research framework is based on Collaborative Learning with Computer Support (CSCL), Characterization of Functions and Mathematical Modeling. The research methodology includes the design of a colaborative learning environment, preparation of CSCL virtual environment to provide: discussion of the difficulties of learning functions, discussion and development of simulators using Modellus software, exploitation of modeling as a teaching and learning methodology, collaboratively. The situation was structured taking as a starting point the instrumentalization of software programmes, the one which supports communication and interaction and Modellus, the modeling software which allows the exploration of situations involving quadratic and affine functions, considering the discussions of CSCL theory. The study analyzes the collaborative work of three undergraduates groups of students. The data shows that the smaller group collaborated more easily than larger groups. The data also show that discussions about the difficulties of the students was where there was greater collaboration. In addition, the script written could not direct participants themselves during the activity, always in need of a mediator intervention. Also some environmental barriers were showed the need to rethink the virtual space, which could provide resources to facilitate communication between participants in the session.

Im CoolSoftware-Projekt wurden Metamodelle, Algorithmen und Architekturmuster für energieeffiziente Software entworfen. Sobald ein komplexer Kontrollfluss auf einem solchen System ausgeführt werden soll, muss das dynamische Energieverhalten in die Optimierung einbezogen werden. Um diese Herausforderung zu lösen, werden in dieser Arbeit die Ansätze von CoolSoftware durch weitere Modellelemente und Algorithmen ergänzt. Unter anderem kommt eine Simulation zum Einsatz, um funktionell mögliche Konfigurationen zu bewerten. Der Kontrollfluss kann durch das Workflow-Management-System Open Service Process Platform definiert werden. Im Ergebnis kann das System den Workflow je nach Komplexität möglichst energiearm ausführen.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Electrical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014 / The IEC 61850 standard, “Communication networks and systems in substations” was promulgated to accommodate the need for a common communication platform within substations for devices from different vendors. The IEC 61850 standard proposes a substation automation architecture that is Ethernet-based, with a “station-bus” for protection devices within the substation and a “process bus” where raw data from the voltage and current transformers are published onto the data network using a device known as a Merging Unit. To date, most of the standardization efforts were focused at the station bus level where event-triggered messages are exchanged between the substation automation devices, commonly referred to as Intelligent Electronic Devices (IEDs). These messages are known as Generic Object Oriented Substation Event messages. Equipment from vendors to accommodate the “process bus” paradigm, however is still limited at present. The Centre for Substation Automation and Energy Management Systems was established within the Electrical Engineering Department at the Cape Peninsula University of Technology with one of its objectives being the development of equipment either for simulation or real-time purposes in compliance with the IEC 61850 standard. In order to fulfil this long-term objective of the Centre, an in-depth understanding of the IEC 61850 standard is required. This document details the efforts at acquiring the requisite knowledge base in support of the educational objectives of the Centre and the research project implements a simulation of a merging unit which is compliant with the functional behavior as stipulated by the standard. This limited functional implementation (i.e. non-real-time) of the merging unit, is achieved through the development of a virtualized data acquisition node capable of synthetic generation of waveforms, encoding of the data and publishing the data in a format compliant with the IEC 61850-9-2 sampled value message structure. This functional behavior of the virtual sensor node which was implemented has been validated against the behavior of a commercial device and the sampled value message structure is validated against the standard. The temporal behavior of the proposed device is commented upon. This research project forms the basis for future real-time implementation of a merging unit.

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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Electrical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology, 2012 / The introduction of the IEC 61850 standard in substations for communication networks and systems by the International Electrotechnical Commission (IEC) in 2003 provided the possibility for communication between devices of different manufacturers. However, the advent of this standard also brought about many challenges associated with it. The challenges introduced by this fairly recent standard of communications in Substation Automation Systems (SAS), and the need for the development of cost effective IEC 61850- compliant devices, motivated the decision of the Centre for Substation and Energy Management Systems within the Electrical Engineering Department of the Cape Peninsula University of Technology to focus on the implementation of the IEC 61850 standard using an embedded hardware platform. The development of an IEC 61850 embedded application requires substantial knowledge in multiple domains such as data networking, software modelling and development of Intelligent Electronic Devices (IEDs), protection of the electrical system, system simulation and testing methods, etc. Currently knowledge about the implementation of the IEC 61850 standard usually resides with vendors and is not in the public domain. The IEC 61850 standard allows for two groups of communication services between entities within the substation automation system. One group utilizes a client-server model accommodating services such as Reporting and Remote Switching. The second group utilizes a peer-to-peer model for Generic Substation Event (GSE) services associated with time-critical activities such as fast and reliable communication between Intelligent Electronic Devices (IEDs) used for protection of the power network. The messages associated with the GSE services are the Generic Object Oriented Substation Event (GOOSE) messages. The use of GOOSE messages for protection of the electrical system is very important in modern substations. Detailed knowledge of the structure of these messages is important in instances requiring fault diagnosis to determine the cause of mal– operation or to address interoperability concerns or when developing custom IEC 61850- compliant devices with limited functionality. A practical protection application (overcurrent) case study is presented where GOOSE messages are exchanged between a commercial IED and an IEC 61850-compliant controller based on an embedded platform. The basic data model and software development of an actuator node for a circuit breaker is proposed using an IEC 61850 communication stack on an embedded platform. The performance of the GOOSE messages is confirmed to be as per the functional behaviour specified, and per the IEC 68150 standard in terms of the temporal behaviour required. This thesis document tables the methods, software programs, hardware interfacing and system integration techniques that allow for the development and implementation of a low cost IEC 61850-compliant controller unit on an embedded systems platform for the substation automation system. The overcurrent case study distributed between a commercial IED (SIEMENS Siprotec device) and the actuator application developed on an embedded platform for this project (DK60 board) is in compliance with the IEC 61850 standard and utilizing GOOSE messaging is successfully completed both in terms of functional and temporal behaviour. This novel research work contributes not only to the academic community, but to the international Power Systems community as a whole. Keywords: IEC 61850 standard, IEDs, GOOSE message, software modelling, software development, substation automation systems, communication stack, embedded systems, actuator.