Gift Young Engineers: An Extra-Curricular Initiative for Updating Computer and Electrical Engineering Courses

The curricula of engineering courses are well defined by the central government for all Brazilian universities. Indeed, there are some mandatory determinations that must be fulfilled prior to the accreditation of any engineering course in Brazil. Modifications must be submitted for evaluation beforehand, resulting in a process that sometimes takes years to be approved. That is a secure way to guarantee that the fundamentals of each engineering program will be part of the students’ carrier all over the country, and at the same time a problem when you need to introduce new technological subjects. That poses a problem when you have new demands for technological curricular components that could express the actual state of the art of modern subjects. Trying to solve these issues some professors from the Federal University of Amazonas developed a flexible extra-curricular program for electrical and computer engineering courses, named Gift Young Engineers. This paper describes the philosophy of these extra-curricular programs. Some examples of successful particular partnerships are also discussed. Indeed the proposed training programs for Digital TV Systems (hardware and software) will be presented and analyzed in details. The obtained results will also be discussed in order to contribute to similar experiences worldwide

Speed control and rotor flux estimation by the induction motor observer.

Os sistemas de controle vetorial de alto desempenho baseados em microprocessadores são muito usados em aplicações industriais. 0 sucesso dos esquemas de controle vetorial depende do conhecimento da posição e da magnitude do vetor fluxo rotórico. Este trabalho apresenta o modelamento, controle do motor de indução por campo orientado direto com estimação do fluxo rotórico por observador. A partir do modelo contínuo idealizado do motor de indução na forma de variáveis de estado, um modelo discreto é derivado e analisado. Com o auxílio das condições de controle desacoplado a estratégia de campo orientado é mencionada. Os reguladores de fluxo, corrente e velocidade são projetados e os resultados da simulação da estratégia de campo orientado direto são apresentados usando o fluxo real. A teoria do observador de reduzida é apresentada e o observador de fluxo rotórico de ordem reduzida para o motor de indução é derivado. A matriz de ganho do observador e o posicionamento dos poios em função da velocidade do motor são propostos. 0 observador de f l u x o rotórico é discretizado. Em seguida, para levar em conta o atraso computacional, os reguladores de fluxo e corrente são discretizados. As funções de transferência do sistema são obtidas usando a transformada Z modificada. 0 critério de Jury e os diagramas polares são usados para selecionar os parâmetros dos controladores de fluxo e corrente. A simulação discreta do sistema acionamento completo é apresentada. Considerando a dependência paramétrica do observador, um observador/identificador baseado no observador estendido de Luenberger é formulado para estimação do fluxo rotórico combinada com a identificação da constante de tempo do rotor. Os resultados da computação do observador/identificador são dados.Microprocessor-based high-performance vector control systems are widely used in industrial applications. The success of vector control schemes depends on knowledge of the position and magnitude of the rotor flow vector. This work presents the modeling, control of the induction motor by direct field with rotor flux estimation by observer. From the idealized continuous model of the induction motor in the form of state variables, a discrete model is derived and analyzed. With the aid of the decoupled control conditions the oriented field strategy is mentioned. Flow, current and velocity regulators are designed and simulation results from the direct oriented field strategy are presented using the actual flow. The reduced observer theory is presented and the reduced-order rotor flux observer for the induction motor is derived. The gain matrix of the observer and the positioning of the poles as a function of the motor speed are proposed. The flicker observer is discretized. Then, to take into account the computational delay, the flow and current regulators are discretized. The transfer functions of the system are obtained using the modified Z transform. The Jury criterion and the polar diagrams are used to select the parameters of the flow and current controllers. The discrete simulation of the complete drive system is displayed. Considering the observer's parametric dependence, an observer / identifier based on the Luenberger's extended observer is formulated for rotor flux estimation combined with the identification of the rotor time constant. The observer / identifier computation results are given

Estimation of parameters and detection of incipient faults of asynchronous machines.

Este trabalho tem por objetivo apresentar contribuições ao estudo de estimação de parâmetros e de detecção de falta incipiente da máquina assíncrona. A partir do modelo dinâmico da máquina, desenvolvem-se modelos de estimação baseados somente nas medições das correntes e tensões estatóricas. Inicialmente, é proposta uma técnica para a estimação em tempo real da resistência estatórica da máquina baseado na aplicação de sinais homopolares de tensão. O modelo proposto é analisado via simulação e experimentalmente. Em seguida, é proposta uma forma de onda de tensão que permite estimar todos os parâmetros da máquina sem auxilio de dispositivos mecânicos. O modelo é avaliado através de resultados experimentais. São ainda desenvolvidos modelos para máquina de assíncrona operando com faltas incipientes. Finalmente, é proposta uma técnica para detecção em tempo real de falta entre espiras no estator do motor assíncrono trifásico.The aim of this work to present contributions to the study of parameters estimation and incipient fault detection winding stator of the asynchronous machine. From the dynamic model of the machine, appropiate parameter estimation models based only in the measurements of currents and the stator voltages are developed. Initially, one technique for the estimation of the stator resistance of the machine based on the application homopolar of voltages signals it is proposed. The considered model is analyzed by simulation and experimentally. After that it is proposed one form of voltage wave that allows to estimate all the remaining parameters of the machine without aid of mechanical devices. The model is evaluated through experimental results.. Models for induction machine are developed operating with incipient faults. Finally, one technique incipient faut detection in real time for inter-turn stator winding faults in three-phase induction motor is considered

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data