Mestrado em Engenharia de Produção

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https://repositorio.ufcat.edu.br/handle/tede/84

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Navegando Mestrado em Engenharia de Produção por Autor "Duarte, Carlos Antonio Ribeiro"

Agora exibindo 1 - 3 de 3
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    Avaliação de potencialidades do processo de soldagem TIG-MIG/MAG com variação de polaridade no eletrodo MIG/MAG
    (Universidade Federal de Goiás, 2019-07-15) Costa, Gabriella Cristina da Silva; Resende, André Alves de; http://lattes.cnpq.br/3492793149542286; Resende, André Alves de; Duarte, Carlos Antonio Ribeiro; Ferreira Filho, Demostenes
    This study proposes a contribution to the improvement of production processes through the study of hybrid welding processes. It aims to evaluate the effects provided by the association of two conventional welding processes on the behavior of the welding voltage and current signals, on the production capacity and on the geometry of the weld obtained. In this case, the arc welding processes TIG (Tungsten Inert Gas) and MIG/MAG (Metal Inert Gas / Metal Active Gas) are associated and give rise to the TIG-MIG/MAG process. The tests were performed following a factorial planning, through simple deposition in SAE 1020 steel plates of 6.35 mm thickness. Experiments were performed varying the polarity of the MIG/MAG part of the process and the current of the TIG part of the process. The data of the voltage and current signals of the TIG-MIG/MAG process demonstrated that at the moment of insertion of the MIG/MAG arc in the process, the signals realigned their intensities in order to stabilize the process. The productive capacity analysis showed that the TIG-MIG/MAG process with the MIG/MAG electrode in direct polarity has better rates of deposition and fusion, if compared with the results obtained for conventional polarity. Through the analysis of variance it was identified that MIG/MAG polarity is the most influential factor in the results of weld bead geometry. The TIG-MIG/MAG process with theMIG/MAG electrode in direct polarity can generate larger widths, penetrations and molten areas and smaller reinforcements when compared to the conventional MIG/MAG process in direct polarity, opening the possibility of welding in this polarity. And finally, the presence of the TIG arc was able to reduce the convexity of the weld beads, regardless of the polarity.
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    Desenvolvimento de um aplicativo colaborativo para compartilhamento de preços de produtos de supermercados
    (Universidade Federal de Goiás, 2020-09-03) Vaz, Lucas Fagundes; Duarte, Carlos Antonio Ribeiro; http://lattes.cnpq.br/3533635470069420; Duarte, Carlos Antonio Ribeiro; Resende, André Alves de; Andrade, João Rodrigo
    Over the years, the constant integration of mobile technologies between suppliers and customers has become a strong ally in the dissemination and sharing of prices quickly and safely. In this context, the present work has as objective, the elaboration of an app for sharing prices of supermarket products. The app was planned and implemented to run on the Android platform. For its preparation, a management and product development planning was initially carried out based on renowned reference models available in the literature. Subsequently, a set of technical tools in the field of computer programming, such as: Android Studio, Java, Jsoup, Zxing and Firebase, were widely used in the development of a functional prototype of the app. As main assumptions, an app was developed with a friendly interface, ease of use, good execution performance and that was able to perform treatments for systemic errors. As a main result, an app was obtained as close as possible to an information system to be put into production. Among the main characteristics obtained from the development of the app, the possibility of reading the Nota Fiscal do Consumidor Eletrônica (NFC-e) through the Quick Response Code (QR Code) and the export of products, prices and other relevant information to the database stands out in order to allow the real-time sharing of information from each NFC-e sent. Additionally, the ability to search for specific products was implemented through key terms to be inserted in a search screen and the option to manage notes sent, with the possibility of verifying monthly expenses for the current year in list and graph format. It is concluded that the tools studied and used in the conception of the app are capable of meeting the established objective and a functional prototype was conceived.
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    Previsão do lead time de processos usando mineração de dados
    (Universidade Federal de Goiás, 2021-03-09) Oliveira, Maíza Biazon de; Cordeiro, Douglas Farias; http://lattes.cnpq.br/5269312530540199; Silva, Núbia Rosa da; http://lattes.cnpq.br/8448585265537772; Silva, Núbia Rosa da; Duarte, Carlos Antonio Ribeiro; Silva, Sergio Francisco da; Cordeiro, Douglas Farias
    The era of Industry 4.0 leads to constant adaptations of production processes and generates a significant amount of information. In this way, information management becomes a crucial factor to guarantee the competitive strategy in the industries. One of the information to be managed is textit lead time, time between the customer requesting an order and it being available. Usually, it can be estimated using expensive measurements or traditional methods that do not normally reflect the actual behavior of the data or do not support the significant amount of information generated in Industry 4.0. In addition, there are gaps in the literature on textit lead time forecasting, such as the use of smart methods to predict textit lead time across the supply chain. In this context, the objective of this research is to use data mining using machine learning algorithms to predict the textit lead time in real processes. The proposed methodology made use of the textit Knowledge Discovery in Databases (KDD) cycle structured in the selection, pre-processing, transformation, data mining and knowledge discovery phases. The learning algorithms for textit Linear Regression (LR), textit Random Forest (RF), textit Support Vector Machine (SVM), textit K-Nearest Neighbors (KNN) were tested and textit Multilayers Perceptron (MLP). To validate the experiments, three databases from the Electronic Information System (SEI), a supply chain from a pharmaceutical logistics sector and from the industrial automation sector for the ceramic sector, were used. The results showed that data mining is an effective tool for analyzing data generated in the fourth industrial revolution for forecasting textit Lead time and decision making on production planning and control.