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Disertaciones |
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1
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CAMILA BARBOSA GOMES DE ARAÚJO
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Virtual Assistant for Operation Centers
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Líder : SAMAHERNI MORAIS DIAS
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MIEMBROS DE LA BANCA :
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IVANOVITCH MEDEIROS DANTAS DA SILVA
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KURIOS IURI PINHEIRO DE MELO QUEIROZ
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ORIVALDO VIEIRA DE SANTANA JUNIOR
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PEDRO THIAGO VALERIO DE SOUZA
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SAMAHERNI MORAIS DIAS
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Data: 13-abr-2023
Ata de defesa assinada:
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Resumen Espectáculo
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The coordination of the electricity sector's operating activities is carried out by a set of tools and technologies, the most notable of which is audio communication between real-time teams of agents and technicians in the field. These calls are recorded, stored, and consulted on demand for auditing and traceability purposes, as well as to support postoperative analyses. However, because of the difficulty in accessing their content, these recordings, which contain relevant information for both system operation and agent billing, are underutilized. Thus, by transcribing them, it is possible to trace and associate these audios with each other and with other records from different operating systems, allowing for the optimization of activities that require a significant amount of time from post-operation engineers. This dissertation describes a virtual assistant for energy generators, transmitters, and distributors' operation centers that transcribes all audio communications from these centers and uses natural language processing techniques to extract information from the audios, classify them into topics of interest to the operation, and correlate the recordings with each other and with operating systems. The system architecture is presented, as well as the audio-to-text transcription models used, the classification module, and the correlation between audios and with SCADA module. The project described here is intended to aid decision-making and contribute to greater efficiency, safety, and operational reliability in electrical system operation and post-operation.
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2
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HUMBERTO GAMA DE CARVALHO NETO
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Black-Box System Identification of a Multilayered Wiener-Hammerstein Model for Distortion Pedals.
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Líder : SAMAHERNI MORAIS DIAS
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MIEMBROS DE LA BANCA :
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KURIOS IURI PINHEIRO DE MELO QUEIROZ
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LUIZ FELIPE DE QUEIROZ SILVEIRA
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SAMAHERNI MORAIS DIAS
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THIAGO MEDEIROS BARROS
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Data: 07-jul-2023
Ata de defesa assinada:
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Resumen Espectáculo
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The advencement of electronics allowed the development of several types of audio effects, mostly applied to musical instruments. One of these effects is distortion, which shaped the sound of electric guitar as we know it today. Equipments that provided such effects became more robust and compact, combined with a greater diversity of tones. The digital electronics allowed the creation of equipments that have several of these effects, called multi-effect pedals, and unities that can model effects. One of the challenges in the development of these equipments is to truly replicate famous distortion tones. For that purpose, it is possible to model the desired effect through full knowledge of its electronic circuit or through modeling based on the identification of the system in question. This work proposes the development, application and evaluation of a parametric multilayered Wiener-Hammerstein model for digital modeling of distortion pedals based on existing pedals. The model parameters will be optimized by a genetic algorithm. The results will be evaluated by frequency-error, mel scale error calculus and through a hearing test.
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3
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THIAGO DE ARAUJO BRITO
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Genetic algorithm optimization of the fuzzy controler of the water level and the pressure of a tube boiler
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Líder : FABIO MENEGHETTI UGULINO DE ARAUJO
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MIEMBROS DE LA BANCA :
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ANDRE LAURINDO MAITELLI
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CARLOS EDUARDO TRABUCO DOREA
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FABIO MENEGHETTI UGULINO DE ARAUJO
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OSCAR GABRIEL FILHO
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Data: 26-jul-2023
Ata de defesa assinada:
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Resumen Espectáculo
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Faced with the constant technological evolutions that modern society experiences, industries have evolved more and more in search of greater efficiency and reliability of their processes. The search for new methods to optimize the industrial activities has fueled the interest in the development of research focused on this area. Despite the various technological developments that industries constantly undergo, steam remains present in their processes since the first industrial revolution, being used to perform movements in machines, which revolutionized the production process of the time. Nowadays its presence remains vast in different types of industry, being widely used for heating and electricity generation. The equipment used for steam generation is the boiler. In the process of generating steam in a boiler, there are two variables of great importance for control, which are the water level and the steam pressure in the drum. The control of these variables guarantees the operational safety of the machine and compliance with the process parameters through the required steam pressure. Thus, the boiler control problem is of great interest in academia and industry. In order to control the variables reported, it is basically necessary to act on the water supply and saturated steam exit valves of the drum. Based on this, this work aims to control the water level and pressure in the drum of a water-tube boiler through artificial intelligence in order to avoid unwanted variations in level and pressure when going through load variations. For this, fuzzy controllers optimized by genetic algorithm are used. Tests were performed for the model and their results were satisfactory.
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4
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WALLISSON FERNANDES MARTINS DOS SANTOS
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Bearings failures detection and diagnosis, under different loads and speeds, by using Convolutional Neural Networks
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Líder : FABIO MENEGHETTI UGULINO DE ARAUJO
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MIEMBROS DE LA BANCA :
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CARLOS EDUARDO TRABUCO DOREA
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FABIO MENEGHETTI UGULINO DE ARAUJO
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MARCELO ROBERTO BASTOS GUERRA VALE
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PABLO JAVIER ALSINA
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Data: 26-jul-2023
Ata de defesa assinada:
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Resumen Espectáculo
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With the increasing complexity and costs of industrial systems, management measures aimed at preventing or mitigating the loss of reliability, decreased productivity and safety risks, caused by process abnormalities and component failures, become increasingly important. . In this context, Artificial Intelligence (AI) has been consolidating itself as an effective and challenging means in the process of monitoring, detecting and diagnosing failures in equipment and industrial systems. Among the equipment, which are frequently the object of studies, bearings stand out, which are critical mechanical components of rotating machines. Vibration monitoring is the most widely used technique for detecting, locating and distinguishing bearing faults. Faced with the efficient and increasing performance of AI techniques and the importance of bearings in industrial processes, this work implements a Convolutional Neural Network (CNN) for detection and diagnosis of faults in bearings, under different loads and speeds in the motor and different types and depth of bearing failures. For the development of the proposed approach, the Case Western Reserve University (CWRU) bearing test database was used. The raw vibration signals were pre-processed through the Continuous Wavelet Transform (TWC) and converted into images, which were fed directly into the developed CNN structure. When compared to other CNN-based methods that used the same database, the proposed approach demonstrated superiority or was at least as successful, achieving an accuracy of 97.7% when tested with files under operating conditions other than operating conditions. training.
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5
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JHONAT HEBERSON AVELINO DE SOUZA
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PID CONTROL OF VIBRATIONS IN SECOND-ORDER SYSTEMS WITH TIME-DELAY USING RECEPTANCE WITH ROBUST STABILITY AND PERFORMANCE OPTIMIZATION
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Líder : CARLOS EDUARDO TRABUCO DOREA
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MIEMBROS DE LA BANCA :
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CARLOS EDUARDO TRABUCO DOREA
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FABIO MENEGHETTI UGULINO DE ARAUJO
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KURIOS IURI PINHEIRO DE MELO QUEIROZ
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JOSÉ MÁRIO ARAÚJO
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Data: 28-ago-2023
Ata de defesa assinada:
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Resumen Espectáculo
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Phenomena such as mechanical vibrations, resonance and oscillations can be mathematically described by second-order differential equation systems, commonly referred to as second-order systems. Working with this type of model, instead of first-order state models, brings numerical benefits, but there are inherent difficulties in determining their physical parameters. The challenges become even more significant when considering the existence of delays between state measurements and actuation signals, leading some approaches to require post-analysis for determining the stability of calculated solutions. An alternative to overcoming the difficulties of parameter measurement is the frequency response approach which utilizes models based on receptance. In view of this issue, this work focuses on the design of PID controllers (Proportional-Integral-Derivative) for linear dynamic systems with delay, modeled by second-order matrix differential equations. It adopts the receptance approach because it is based on the frequency response of the system, enabling precise treatment of closed-loop stability, without the need for approximations or back-testing of delay terms. To ensure robustness and performance, as well as minimize the Absolute Error Integral relative to the tracking of a constant reference, it formules an optimization problem for the determination of controller gains. Also, it takes into account a pre-established stability margin. To solve the optimization problem, it implements a Genetic Algorithm. Unlike related works in the literature, the proposed method can be equally applied to systems with open-loop poles in the right half-plane.
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6
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GLEILSON DE MEDEIROS LIMA
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Smoothing of Oscillations in Sprayer Boom with Input Shaping and Robust Adaptive Model Reference Control
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Líder : JOSENALDE BARBOSA DE OLIVEIRA
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MIEMBROS DE LA BANCA :
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DIAN LOURENÇONI
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ADEMAR GONÇALVES DA COSTA JÚNIOR
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JOSENALDE BARBOSA DE OLIVEIRA
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LEONARDO RODRIGUES DE LIMA TEIXEIRA
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Data: 15-dic-2023
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Resumen Espectáculo
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Agricultural productivity directly depends on the efficient application of fertilizers and plant protection products, which is usually carried out by ground spraying with a spray boom attached to the tractor. The need for the agricultural spray boom to be parallel to the ground during operation requires active suspension systems with controllers that reduce as much as possible the oscillations associated with the rolling movement. This work proposes the integration of the open-loop technique of zero-vibration (ZV) input shaping with robust model-based adaptive controllers, the MRAC and the VS-MRAC, comparing the results of two-degree-of-freedom (2-DoF) configurations. The robustness of VS-MRAC + ZV is evidenced with promising results in tracking and control signal when it is integrated into input shaping.
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