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This paper proposes methods for improvement electrical grounding systems performance. There is a intense need for efficient electrical protection systems, to protect people and property against electric currents discharges, thus adding improvements to electrical grounding systems already in use. Based on this principle, this work is divided in: i) soil resistance values variation, due to different...
In this work, it is proposed to calculate the sensitivity of parameters, based on analytical calculation, of repowered system between two electric generators, an induction generator and a synchronous generator, connected to a common bus in permanent regime, subject to a non-linear load. It is proposed a repowered system with simulated data where, based on percentage variations in the base values of...
One of the most discussed schedule in Brazil is Education, and with it comes a lot of problems to solve. This project use of artificial intelligence, but precisely in the area of Machine Learning, to enable a solution, in relation to student monitoring. The research has done with students of technical high school education at the Federal Institute of Gois — Brazil, to find a method which would be...
This paper presents a comparison between the performances of LBP and Haar features in a Cascade Classifier, which aims automatically to count immature whiteflies (nymphs). The relevance of counting these nymphs is related to pest management, which leads to an increase in food production. Evaluate differences in weak classifiers can lead to better understanding and implementation of object detection...
This paper presents an improvement of the optimization methodology of luminaire built by high power light emitting diode (LED) matrix. Six parameters that modify the geometry and layout of the luminaire are evaluated through a parameter sensitivity study. The result indicates that five parameters have an equally distributed sensitivity index, while one parameter presents an index with less than 1%...
The presence of gaps in time series makes the data analysis process difficult. Although there are several methods for filling such gaps, they do not present satisfactory results as the gap widens. The proposal of this paper is to present a new methodology that uses techniques of extraction of characteristics and identification of systems to fill the missing data. The proposed methodology was applied...
The purpose of this work is to present a new methodology to be applied in precision agriculture. In order to replace traditional methods, that are expensive, affect the environment and must be improved, it is presented the equipment and process of phytosanitary management using acoustic vibration in order to obtain correct application of product. The methodology is presented, in two case study: i)...
This paper presents comparative study between Fuzzy and Predictive controllers. They are implemented to speed control of a direct current (DC) machine, triggered by fully controlled three-phase AC-DC converter. Searching for high performance controllers, it's performed controllers' parameters optimization, through the use of the heuristic method Genetic Algorithm. It seeks to determine which of the...
This paper presents a speed control for a DC motor. Despite the unknown parameters of the plant to be controlled, these parameters are found using a system identification method. The methodology implemented in this study is known as parametric regression and is based on an optimization technique. This optimization, through its fitness function, allows to find the system characteristics in order to...
The purpose of this work is to find the values of the electric parameters of synchronous and induction machines in order to validate the electrical interactions between an induction generator and a synchronous generator. The two generators will be connected in two ways: i) isolated to the common bus and ii) jointly connected to the common bus in permanent regime, subject to non-linear load. The results...
The purpose of this work is to calculate Surge and Swab pressure in oil wells with eccentricity between drill string and wellbore or casing string. Analysis of this phenomenon, in which the fluid is confined between two eccentric cylinders, are made. The conformal mapping is used to lead the eccentric domain into the concentric domain, since the usual models correspond to concentric geometries. The...
This paper proposed experimental method that uses geoelectrical prospection to correlate variations in the soil electrical resistivity produced by the application of agricultural supplies, such as nitrogen, phosphor, potassium and limestone. The proposed method uses a three-dimensional stratification methodology to enable the mapping of soil dynamic aimed in the different proportions of supplies applied...
This paper is an experimental and theoretical method developed for in situ applications that uses a geoelectrical method, the Wenner method, to correlate the changes in electrical resistance of soil produced by chemical fertilization. The developed methodology enables: i) map different influences of some fertilizers in the soil non-invasively, ie, it is a non-destructive method of soil evaluation,...
This paper is an experimental and theoretical method developed in laboratory bench that uses a geoelectrical method, the Wenner method, to correlate the changes in electrical resistance of soil produced by chemical fertilization. The developed methodology allowed to know the dynamic behavior that some common fertilizer causes on the electrical resistance measurements of the soil under study. The applied...
This paper presents methodology for validation of soil compaction measuring devices based on cone index, allowing procedures such as: i) comparison between equipment, ii) analyzes of accuracy and iii) repeatability, important parameters in the validation of measurement instruments. The methodology consists in using soil samples with a particular compaction discretized from the height of the mold used,...
This paper aims to simulate and analyze an isolated full-bridge DC/DC boost converter, for photovoltaic panels, running a modified perturb and observe maximum power point tracking method. The zero voltage switching technique was used in order to minimize the losses of the converter for a wide range of solar operation. The efficiency of the power transfer is higher than 90% for a large solar operating...
This paper deals with the calculation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for soil stratified in two layers. Moreover, the results obtained by the Variable Currents Method (VCM) have been compared...
In modern agriculture, the knowledge of the soil properties is a key factor for profitability in the production. However, data acquisition and processing are limiting factors for its use, since they require specialized labor. The automatic instrument that provides information about soil penetration resistance, which is described here replaces the traditional system and automatically obtain reliable...
The purpose of this work is to calculate the Surge and Swab pressures on oil wellbore wich has eccentricity between the drill column and the well. An analysis of the couette phenomenon is performed, in which the fluid is confined between two eccentric cylinders. The conformal mapping is used to turn the eccentric domain in the concentric domain, since the usual models correspond to concentric geometries...
This paper presents the study of the relationship between soil apparent electrical resistivity ρa and i) the moisture content, ii) clay content and iii) soil compaction, for use of the ρa as a mapping tool of spatial soil variability. It was held measures of ρa in different soil types, varying moisture content gradually while maintaining a constant compaction, and then varying the compaction and relating...
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