EMC - Escola de Engenharia Elétrica, Mecânica e de Computação

URI Permanente desta comunidade

http://200.137.215.59//handle/ri/587

A Escola de Engenharia Elétrica, Mecânica e de Computação (EMC), da Universidade Federal de Goiás, oferece Graduação em: Engenharia Elétrica, Engenharia Mecânica e Engenharia da Computação. Além de Especialização em: Telecomunicações; Instalações Elétricas; e, Gestão de Negócios.

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Agora exibindo 1 - 20 de 150

A inspeção técnica veicular e seu impacto no comércio de veículos usados
(Universidade Federal de Goiás, 2023-08-14) Libório, João Pedro Neri; Oliveira, Ademyr Gonçalves de; Oliveira , Ademyr Gonçalves de; Figueiredo, Kleber Mendes de; Franco, André Luiz Carneiro
The present work aims to present the Vehicle Technical Inspection (ITV) alongwith all its technical standards regarding vehicle safety and emission of gases, anddemonstrate how the lack of standardization and regulation by the State leads to aprecarious aging of the Brazilian vehicle fleet, resulting in incalculable damagesdirectly and indirectly to the population. According to the Federal Highway Police, asignificant portion of vehicular accidents occurring in the country today are caused bymechanical defects and lack of maintenance. This explanation illustrates how thistype of accident ends up burdening the Brazilian public healthcare system throughhospitalizations and medical procedures. Additionally, the project also aims toanalyze how the ITV can impact the trade and maintenance of used vehicles in thecountry, highlighting the lack of reliability perceived by a considerable portion of thepopulation, including dealers, intermediaries, mechanical workshops, and the finalcustomer, regarding second-hand automobiles, as it is notorious that a large numberof vehicles with numerous mechanical and structural defects are licensed and solddaily. Lastly, it also seeks to understand and compare how the ITV is practiced inother developed countries, including its standards and obligations, as well as itsperiodic implementation at workstations, in order to explore possible new solutionsand improvements for Brazilian regulations and standards, by adapting successfulexperiences from other global contexts.
Abastecimento de veículos elétricos considerando energia fotovoltaica
(Universidade Federal de Goiás, 2019-07-11) Oliveira, Giovanni Filipe Leone; Santos, Euler Bueno dos; Valle, Ana Cláudia Marques do; Santos, Euler Bueno dos; Belchior, Fernando Nunes
With the popularization of electric vehicles, the need to install recharging stations will become imminent. It is expected that in Brazil, the adoption of electric vehicles to decarbonize the transportation sector will be slower than in the rest of the world, due to biofuels. However, it is certain that electric vehicles will be a considerable part of the fleet in the future and may have a profound impact on the electric grid.The advantages of deploying recharging stations can be verified when it is possible to userenewable energy sources. It should be noted that the use of renewable sources has the benefit of reducing harmful gases into the environment. This work addresses important electrical devices related to the subject of electric vehicles and photovoltaic generation. In addition, it proposes a hypothetical electric vehicle recharging station in the city of Goiânia-GO. An economic analysis of a photovoltaic generation system is presented to attend said station, considering the space available for accommodating the photovoltaic modules.There are also two financial scenarios where bank financing and the use of equity are considered.
Adaptação e implementação da framework NIST em redes domésticas
(Universidade Federal de Goiás, 2024-01-31) Soares, Luan Weba; Pinheiro Júnior, Carlos Galvão; Pinheiro Júnior, Carlos Galvão; Oliveira, Marco Antonio Assfalk de; Alves, João Miguel Estevão
This study addresses the implementation and feasibility of the National Institute of Standards and Technology Cybersecurity Framework (NIST CSF). We explore the challenges brought by the rise of remote work in residential environments, both of which contribute to a more complex security landscape. Using the Raspberry Pi equipped with security tools such as SIEM and EDR, and vulnerability scanning techniques, the study proposes a comprehensive set of security practices based on the NIST CSF. It aims to provide a clear, low-cost roadmap for effectively modeling cybersecurity measures, protecting data integrity and privacy on home networks. Finally, we arrived at the result that the framework is adaptable, but requires a lot of intervention from specialists, to the point that support by them rather than the end user is more appropriate.
Adequação de uma ferramenta off-line para a programação de um robô manipulador dedicado ao processo de manufatura aditiva por deposição a arco
(Universidade Federal de Goiás, 2023-11-08) Matos, Giovana Andrade de; Ferreira Filho, Demostenes; Ferreira Filho, Demostenes; Fonsceca, João Paulo da Silva; Lopes, Gustavo de Castro
The Wire Arc Additive Manufacturing (WAAM) process has great potential for the manufacture of metallic parts. However, although the procedures are similar to those used in polymer 3D printing, which is already established as an industrial process, WAAM still faces several challenges to become mature enough to be applied on a large scale in industry. One of the ways to carry out the WAAM process is through manipulator robots, which play a significant role in this technique. Deposition trajectories can be generated in two main ways: by "teach" mode or by "Offline" programming. This project adapted a commercial off-line programming tool for the application of the WAAM process through the development of a virtual workstation identical to the one available at the Laboratory of Materials and Manufacturing Processes, programming of the robotic cell using the RoboDK software and the Teach programming mode, and the manufacture of a part with a complex shape (airfoil NACA 04) by the WAAM process.
Ajuste dos ganhos de um regulador de velocidade tipo PI para acionamento elétrico a velocidade variável utilizando-se o algoritimo Simulated Annealing
(Universidade Federal de Goiás, 2019-12-18) Santos, Guilherme Fernandes dos; Silva, Wander Gonçalves da; Silva, Wander Gonçalves da; Oliveira, Marco Antônio Assfalk de; Guimarães, Gisele
The project consists in developing an algorithm in the MATLAB® environment to find the best tuning for a PI speed controller using the Simulated Annealing Method. An independently excited DC motor with an inner armature current control loop with another PI controller was used and modelled in the SIMULINK® environment. In order to keep the system linear, the gains of the PI current controller are adjusted so that, for the rated armature current reference, the armature voltage applied to the motor does not exceed its rated value. The speed control was realized in an outer control loop with the gains limited so that, for a specific speed demand, the armature current reference does not exceed its rated value. A nonlinear model was considered where a saturator block was placed at the exit of the PI speed controller to limit the armature current reference to the PI current controller.
Alocação de recursos em redes sem fio utilizando algoritmos baseados em aprendizagem de máquina
(Universidade Federal de Goiás, 2024-02-01) Lopes, Adriano Ferreira; Silva, Jean Lucas Barbosa; Vieira, Flávio Henrique Teles; Vieira, Flávio Henrique Teles; Cardoso, Alisson Assis; Carneiro, Daniel Porto Queiroz
With the increasing rise in the number of mobile devices and intelligent IoT devices, wireless networks have become increasingly complex, autonomous, and heterogeneous in terms of the types of network architectures they incorporate. Within these networks, efficiently allocating and managing resources for users is a significant problem to be solved. In this context, deep reinforcement learning techniques are expected to be among the main technologies used to achieve global optimization in dynamic resource allocation. This paper presents a proposal for resource allocation in wireless networks, termed Cross-Entropy Reinforcement Learning, in order to maximize energy efficiency and meet users’ quality of service (QoS) requirements. The approach considers a multi-user, multi-objective communication system based on CP-OFDM (Cyclic-Prefix Orthogonal Frequency Division Multiplexing) technology using reinforcement learning methods, specifically a Deep Q-Network (DQN) associated with the CrossEntropy algorithm to obtain an optimal resource allocation policy. The implementation encompasses system parameters such as bandwidth, modulation, number of users, and average packet size, while detailing the structure of resource elements, subcarrier distribution, and transmission capacity in different modulation modes within the LTE (Long Term Evolution) system frame. Simulation results demonstrate that the proposed method exhibits good convergence characteristics and performs better than the traditional DQN approach without cross-entropy.
Análise comparativa entre as leituras de valores RMS de diferentes medidores, diante de sinais senoidais e distorcidos
(Universidade Federal de Goiás, 2019-07-09) Cunha, Luiza Ferreira da; Belchior, Fernando Nunes; Belchior, Fernando Nunes; Oliveira, Antônio Melo de; Nerys, José Wilson Lima
In order to meet the need for equipment that emulates different load conditions in electric motors, the system described in this article was designed in conjunction with Prof. Dr. Geyverson Teixeira, to be incorporated into the laboratories of the Federal University of Goiás. Using a simplified architecture in the design, the construction, use and maintenance of the system can be done quicklywith components easily found in the market. The premise of the equipment is to drain an electric current with known value from an electric generator, so that by varying the value of this current, a load can be emulated on the generator shaft. The power value is controlled from a Pulse Width Modulation (PWM) generator, where the pulse duration determines an average current value. The power generated will be dissipated into a specific resistor, designed for high power dissipation, coupled to a temperature monitoring sensor and cooling system, to prevent overheating and damage. Information about the system will be displayed on an LCD display for operation.
Análise da aplicação de RPA para atualização de segurança de senhas
(Universidade Federal de Goiás, 2023-08-07) Borges, Mariana Inácia Xavier; Castro, Marcelo Stehling de; Castro, Marcelo Stehling de; Guedes, Leonardo Guerra de Rezende; Pinheiro Júnior, Carlos Galvão
With the rapid advancement of technology, the virtual environment has become an extension of human life. As a result, information security has become an extremely important aspect in ensuring individuals' privacy. Authentication using passwords is currently the most common way to reaffirm this privacy. However, the careless use of passwords can lead to personal and professional consequences, as most data breaches in companies related to cybercrimes are associated with weak and reused credentials of their employees. This article proposes an analysis of password security using a Robotic Process Automation (RPA) tool to verify and maintain the security of passwords used in a corporate environment.
Análise da eficiência energética em função da troca de motores de indução em uma empresa de saneamento
(Universidade Federal de Goiás, 2020-01-15) Souza Neto, José Gois Pery; Santos Neto, Miguel Alves dos; Belchior, Fernado Nunes; Belchior, Fernando Nunes; Veloso, Eduardo José Frauche; Castro, Marcelo Stehling; Oliveira, Antonio Melo de
This paper has as main objective to analyze the motors of a sanitation company and to calculate the energy efficiency obtained when replacing the standard motors with high performance motors. Therefore, it was necessary to create an interface that would allow us to determine the financial savings by replacing standard induction motors with high efficiency induction motors. For the execution of the interface was used Excel software, making use of its macros and VBA to create the program. One of the big problems with the induction motors employed today by the sanitation company is their performance, as these motors have been running for a long time and their performance is no longer the same, to the point of providing quite different performance than they were designed to attend, which makes them consume more energy than necessary, increasing the energy costs of sanitation companies, making this one of the main operating costs in the companies. For this reason, investing in energy efficiency by switching from standard induction motors to high performance induction motors is important as they have considerably reduced energy costs in sanitation companies. With the study it is verified that the motors used in a sanitation company are important for the costs of the same, since they are related to pumping, which is the basic activity of supply systems, therefore all operational cost reduction in them is relevant to mitigate costs, to enable the expansion of the scope of basic sanitation.
Análise da influência do pré-aquecimento, gás de proteção e tecimento na diluição e dureza de revestimento de inconel 625 ao substrato de aço carbono por processo MIG/MAG
(Universidade Federal de Goiás, 2018-12-10) Speziali, Lucas Moura; Ferreira Filho, Demostenes; Ferreira Filho, Demostenes; Figueiredo, Kleber Mendes de; Gonçalves Júnior, José Lúcio
Welding coating is an increasingly used method for the manufacture of wear and corrosion resistant parts, since it allows the manufacture of parts with lower cost materials, applying more noble materials to the surface to achieve the desired properties. The present work deals with the influence of the variation of three parameters on the coating of a Nickel alloy (Inconel 625) by MIG / MAG welding on a carbon steel substrate, varying the protection gas and the preheating temperature, with the purpose of determining the most suitable parameter to perform the coating process in function of not having high dilution of the weld bead in the substrate, concurring in significant losses in the hardness of the coating material. Welding is also contemplated with the weaving technique, in order to assess whether or not the use of weaving is advantageous for the process. The main results were increased dilution for use of the fabric, increase of the preheating temperature, and larger amounts of active gas in the protection gas. For welding with Ar + 25% He also increased the dilution for higher preheating temperatures. With increasing dilution, for higher temperatures and active gas there was reduction in hardness. The weave had no clear behavior with respect to the hardness of the coating.
Análise de correção do fator de potência em redes de distribuição com geração fotovoltaica
(Universidade Federal de Goiás, 2023-05-23) Vilela, Rafael Dezidério; Sousa, Vagner Vilela de; Garces Negrete, Lina Paola; Brigatto, Gelson Antônio Andreâ; Brigatto, Gelson Antônio Andreâ; Garces Negrete, Lina Paola; Belchior, Fernando Nunes
The implementation of photovoltaic generation in electricity distribution networks can help reduce losses and improve the voltage profile of the network. Photovoltaic generators typically operate their inverters with a unity power factor, which impacts their economic feasibility studies. However,operating photovoltaic generators with a power factor close to unity can also bring benefits to distribution networks by providing reactive power injection into the insertion network. This work aims to present an economic feasibility study for the case of a photovoltaic generator that operates its inverters close to the unity power factor, even if this option implies a reduction in active power generation. The study focuses on the remuneration for the provision of this service by the photovoltaic generator, and distribution networks of 10, 33, and 69 buses were used for testing and analysis of results with the proposed modeling. Based on the results, the locational character is noted as a major factor that defines the economic viability for changing the power factor, presenting positive and negative results depending on the insertion bus of the photovoltaic generator.
Análise de faturas de energia elétrica da Universidade Federal de Goiás com vistas à otimização de custos associados a este insumo
(Universidade Federal de Goiás, 2018-11-30) Ferreira, Leonardo da Cruz; Ferreira, Lorena Ediluna; Belchior, Fernando Nunes; Belchior, Fernando Nunes; Oliveira, Antônio Melo de; Castro, Marcelo Stehling
Conserve the financial balance of a company turns into a challenge for any managemen mainly in economic crises which decrease the company incomes. Besides the increase of essential inputs, a electric energy, the challenge gets worse, when the actual energy supply contracts do not offer to consumer the option to choose their providers. In cases as universities, the right to contract energy supply decreases cost and can be used for institution benefit. The knowledge that can simplify management of resources are importan to reduce costs and relieve risks in a decision, mainly with highly consumers. The objective for this project i show the methodology for contract energy supply context (even in the free energy market, as regulated energ market), optimizing the best contracts for Federal University of Goias.
Análise de fluxo de carga com técnicas de esparsidade
(Universidade Federal de Goiás, 2019-12-16) Rodrigues, João Paulo Silva; Santos, Suzana Tavares dos; Arruda, Colemar; Arruda, Colemar; Brigatto, Gelson; Calixto, Wallisson
This paper presents an approach to the load flow problem aiming to show that the sparse characteristic, present in most matrices defined in this problem type, can be used in order to obtain computational advantages when implementing/executing programs that will process the different variables of electrical power systems
Análise de sistemas de ventilação e ar-condicionado utilizando técnicas de Dinâmica dos Fluidos Computacional com software livre
(Universidade Federal de Goiás, 2023-08-14) Gratão, Gustavo Gonçalves; Mariano, Felipe Pamplona; Mariano, Felipe Pamplona; Nascimento, Andreia Aoyagui; Vilela, Carlos Alberto de Almeida
In this work, the importance of indoor air quality for people's health was emphasized, highlighting the relevance of an adequately ventilated and air-conditioned environment for the well-being and comfort of occupants. Analyzes of different ventilation and air-conditioning systems were carried out using computational fluid dynamics techniques with free, open source and free software. Simulations of internal air flows in an enclosure were conducted using OpenFoam, while the data obtained were processed using Paraview. The computational experiments results were promising, with the model employed providing satisfactory results. These results demonstrate the potential application of the methods used in other analyzes and provide valuable information for the optimization of ventilation and air conditioning systems in different environments.
Análise do desempenho de filtros harmônicos sintonizados e eletromagnéticos de sequência zero
(Universidade Federal de Goiás, 2019-07-09) Tavares, Carlos Henrique Soares; Ribeiro, Pedro Henrique Alves; Belchior, Fernando Nunes; Belchior, Fernando Nunes; Oliveira, Antônio Melo de; Santos, Euler Bueno dos
The purpose of this work is to compare the third order harmonic current filtering between the tuned passive filter and the zero-sequence electromagnetic filter for balanced loads and unbalanced loads.
Análise do desenvolvimento socioeconômico em relação à utilização de fontes de energias renováveis no Brasil
(Universidade Federal de Goiás, 2018-12-19) Cataneo, Davi Meneses; Valle, Ana Cláudia Marques do; Valle, Ana Cláudia Marques do; Pedroso, Bruno Cosse; Hamberger, Paula Andréa do Valle
Many studies have demonstrated the power consumption in general as a principle for the social and economic development of a region. In this thesis was examined the relationship of renewable energy (hydro, solar and wind energy) with economic and social development (IBC). The country of study was the Brazil, being the temporal space ranging from January 2003 until October 2018. Applying the auto regressive Vector (VAR) Test and the Cointegration Test of Johansen (1988). The monthly data analysis was used to check the linearity between economic development and theuse of renewable energies.
Análise do fator de potência em instalações elétricas contendo geração solar fotovoltaica
(Universidade Federal de Goiás, 2023-07-21) Rezende, Gabriel Portella; Dias, Dayanne Ferreira; Oliveira, Janine Cavalcante de; Belchior, Fernando Nunes; Castro, Marcelo Stehling; Belchior, Fernando Nunes; Santos, Josephy Dias; Oliveira, Janine Cavalcante de
The main objective of this study is to analyze the power factor in electrical installations that incorporate solar photovoltaic generation systems. Distributed generation of electricity through photovoltaic systems has gained increasing importance due to its capacity to produce clean and renewable energy. However, the integration of these systems into existing electrical grids can present challenges, such as the impact on the power factor. Therefore, this study proposes a detailed examination of the effects of generation on the power factor in electrical installations. For this, measurements and analyses will be conducted at the Centro de Aulas das Engenharias building during November 2022 to obtain concrete data and support the study's conclusions. The expected results of this work will contribute to a better understanding of the effects of photovoltaic systems on the power factor and provide guidelines for the design and operation of electrical installations that include solar generation. This aims to optimize the use of electricity, reduce losses, and increase the energy efficiency of these installations.
Análise do projeto do tubo de impedância do laboratório de mecânica aplicada da Universidade Federal de Goiás baseado na norma ISO 10534-2
(Universidade Federal de Goiás, 2023-02-15) Barbosa, Pedro Henrique do Amaral Coelho; Fagundes Neto, Marlipe Garcia; Fagundes Neto, Marlipe Garcia; Kitatani Júnior, Sigeo; Nishida, Pedro Pio Rosa
The objective of this work is to analyze the experimental apparatus of the impedance tube of Laboratório de Mecânica Aplicada (LabMEC), of Escola de Engenharia Elétrica, Mecânica e de Computação (EMC) of Universidade Federal de Goiás (UFG), which experimental routine is stated by the norm ISO 10534-2/1998, and with that identify potential problems caused by non-compliant items between ISO and prototype construction. After identifying them, an intervention proposal was made with the manufacture of new parts, and with that a series of measurements were made involving two samples of acoustic foams, involving the original configuration of the impedance tube, as well as two new intervention proposal configurations. With the data in hand, they were compared in combinations of 2 in order to isolate the variables and observe separately the effect of the items in disagreement with the standard. It was possible to observe the change in the behavior of the results separately, and then as a whole.
Análise do sistema fotovoltaico implementado no Centro de Aulas das Engenharias
(Universidade Federal de Goiás, 2019-12-12) Santos, Josephy Dias; Oliveira, Antônio Melo de; Oliveira, Antônio Melo de; Belchior, Fernando Nunes; Castro, Marcelo Stehling de
This work has the main objective to analyze the generation of its own electricity through the grid-connected photovoltaic system (PV) installed at the Centro de Aulas das Engenharias (CAE) at the Colemar Natal e Silva Campus through an energy efficiency notice opened by the local ENEL concessionaire, whose Federal University of Goiás was contemplated by the P&DI 656 project. The power generation analysis of the own generation took place in a secondary way, where some parameters for the month of September were analyzed, such as: steady state voltage, power factor, harmonic distortions of current and voltage and voltage unbalance. The analysis of the own generation took place in a detailed way where they were approached: the way of the sun to the city of Goiânia-GO, presentation and use of data from the meteorological station installed in Bloco B of the Engineering square, a study of local irradiation based on the history of four years is the time the station was installed, comparison of solar radiation data provided by the local station and traditional sources such as Radiasol, SUNDATA and PVSyst, design conditions, analyzing compliance with national and international operating conditions. A comparison between both forms of operation of the inverter, building orientation, power generation study, performance rate analysis, temperature influences on generation, ways of power generation compensation and investment payback. At the end, conclusions were drawn about electric power generation by addressing the conditions of generation of SFV installed in CAE. This study is necessary since the proper operation of the inverter and photovoltaic modules are directly related to the power product and the functional analysis is crucial to determine if the operating conditions and designs are occurring and the return time of investment.
Análise modal estática aplicada ao problema de fluxo de carga em coordenada retangular para avaliação de estabilidade de tensão
(Universidade Federal de Goiás, 2024-02-02) Sena, Katarina Leite de; Santos, Vinícius Morais Calixto dos; Brigatto, Gelson; Kopcak, Igor; Kopcak, Igor; Alves, Antônio César Baleeiro; Garcés Negrete, Lina Paola
A voltage instability is a phenomenon directly linked to the inability of an electrical power system to meet its demand for active power, caused by inadequate reactive power support. Traditionally, voltage stability margins are calculated through static methods based on the load flow problem. Additionally, Static Modal Analysis has been a tool foridentifying critical buses or areas regarding voltage stability. This methodology uses the representation of voltage phasors in cylindrical or polar coordinates. In contrast, this study proposes applying Static Modal Analysis to the Jacobian of Load Flow in Rectangular Coordinates, where voltage phasors are represented by their Cartesian coordinates on the real and imaginary axes. The aim was to assess whether this new approach could provide additional qualitative information for identifying critical buses regarding voltage stability, complementing traditional Static Modal Analysis. For the analysis of results, well-known transmission networks from the literature were employed, and for comparing the performance of the methods developed in this study, Static Modal Analysis in polar coordinates was adopted as a reference. The results obtained demonstrate that the method developed in this study is satisfactory, as the provided voltage stability margins are close to those of the traditional method, and the Static Modal Analysis applied to Rectangular Load Flow classified the critical buses of the tested systems correctly.

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