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Dissertations/Thesis

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2023
Dissertations
1
  • Yuri de Matos Alves de Oliveira
  • Optimal Guidance and Control of Autonomous Underwater Vehicle for Docking Task

  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • ROBERTO KAWAKAMI HARROP GALVÃO
  • FABRICE LE BARS
  • JEREMY NICOLA
  • LEIZER SCHNITMAN
  • Data: Apr 14, 2023


  • Show Abstract
  • The insertion and removal of autonomous underwater vehicles (AUV) are operations of high cost, duration and risk for operators. A possible solution to reduce these three factors is the replacement of these operators by unmanned surface vehicles (USV). A fundamental step for autonomously removing the AUV is docking, which is the moment when the AUV enters the mobile docking station (DS), which in turn is being towed by the USV. The AUV control algorithm must ensure that the DS is in the field of view (FOV) of the AUV sensors, as well as that the AUV is in the FOV of the DS sensors. Furthermore, the controller must control the AUV precisely to avoid unwanted collision between the AUV and the DS.

    A controller widely used in the literature to solve these problems is the model-based predictive controller (MPC). However, most mooring MPCs do not consider DS movement prediction in their optimization problem. Furthermore, several docking MPCs consider that the objective of the MPC is to bring the AUV into the same pose as the DS. However, at the end of the docking maneuver, the AUV must be in a pose and with a speed relative to DS, not the same. Thus, for the docking of an AUV, this relative pose and velocity must be considered in the controller's reference calculation. Therefore, the purpose of this work is to take into account this relative docking pose and the prediction of its movement in the MPC.

     

    Finally, this work also proposes to maintain contributions already made by other works. Such contributions are MPC implementations of thruster limits, ensuring the AUV is at the DS FOV, and ensuring the DS is at the AUV FOV.

    To validate the proposal of this work, the solution was tested in a simulation environment in Gazebo, in which the underwater dynamics were computed by the UUV Simulator [1]. The robot operating system (ROS) framework [2] and the Casadi optimization library [3] were
    used for the development of the controller and for its connection with the simulator. For the test cases, the parameters and the 3D model of the BlueROV2 Heavy commercial submarine vehicle were used to represent the DS and the AUV in the simulation.

    Two test cases were elaborated to demonstrate the efficiency of the prediction of the movement of the docking pose in the MPC, one with a vertical oscillation of the DS and the other with a rotational and horizontal movement. The FOV constraints and the docking pose prediction were successfully tested simultaneously for the test case with vertical oscillation, but because it was too computationally expensive, the AUV FOV constraint was removed for the other test. For both test cases it was concluded that the
    docking is reduced and that the error between the AUV pose and its docking pose is smaller when DS motion prediction is performed.

2
  • Victor Santos Matos
  • Embedded predictive control based on fuzzy model for electrical submersible pump-lifted oil wells

  • Advisor : MARCIO ANDRE FERNANDES MARTINS
  • COMMITTEE MEMBERS :
  • MARCIO ANDRE FERNANDES MARTINS
  • DANIEL MARTINS LIMA
  • THIAGO PEREIRA DAS CHAGAS
  • FLAVIO VASCONCELOS DA SILVA
  • Data: May 16, 2023


  • Show Abstract
  • Advanced control techniques are not yet a consolidated reality in the oil and natural gas artificial lift sector, mainly in electric submersible pumping (ESP) systems. Model-based predictive controllers (MPC) need accurate and well-representative models, but phenomenological modeling can be expensive and complex due to the dynamics involved. Therefore, data-driven approaches are a robust option to deal with complex phenomena (fluid and thermodynamic) during the production process, in a more economical and effective way. The fuzzy Takagi-Sugeno-Kang (TSK) inference systems is able to approximate the nonlinear dynamics of the elevation systems through a set of linear submodels. Adding this approach to the MPC, it is possible to use a linear control structure and, therefore, numerically-computationally simplified, however, with the appropriate precision and representativeness for the process. Forming a favorable condition for the use in artificial elevation systems, which commonly have isolated installations, dependent on dedicated control systems. The proposal of this work is characterized as the synthesis of a predictive controller with guaranteed feasibility, therefore implementable, with a fuzzy TSK prediction model for ESP-type elevation systems with low computational cost. The focus is the direct application of the technique through the embedding in microcontrollers, simulating the industrial control infrastructure. The case studies implemented on an ESP system through the hardware-in-the-loop approach validated the representativeness of the TSK model and the control capacity and feasibility of the technique, in view of the set of typical restrictions and the reduced number of measured variables.

3
  • Marcela Alves Pereira
  • Reliable and Real-Time Group Communication Protocol for Vehicular Coordination over Vehicular Ad Hoc Networks

  • Advisor : ALIRIO SANTOS DE SA
  • COMMITTEE MEMBERS :
  • WEVERTON LUIS DA COSTA CORDEIRO
  • ALIRIO SANTOS DE SA
  • RAIMUNDO JOSE DE ARAUJO MACEDO
  • Data: Sep 15, 2023


  • Show Abstract
  • Vehicular Ad hoc Networks (VANETs) constitute a specific type of mobile ad hoc network in which nodes are vehicles capable of sending and receiving messages directly between each other using wireless communication links, enabling the creation of several distributed applications without the dependence on a specific infrastructure for vehicle communication. In urban and highway environments, VANETs have been seen as an opportunity in the development of Intelligent Transportation Systems (ITS), aiming not only to improve traffic flow, security, and well-being but also to reduce pollutant emissions. However, many distributed applications for ITS require groups of vehicles to coordinate their actions consistently, reliably, and with temporal constraints. Nevertheless, in VANETs formed in urban and highway environments, vehicles travel along pathways exhibiting a mobility pattern and highly dynamic communication structure. Therefore, network topology changes, communication link disconnections, and message losses are frequent in a VANET. Hence, meeting the requirements for vehicle coordination in distributed ITS applications based on VANETs represents a challenge. In this context, this work proposes the Vehicular Causal Block Protocol (VCBP) to support the vehicle coordination requirements in distributed ITS applications based on VANETs.The proposed group communication protocol offers the facility of message multicast with guarantees of reliable delivery, temporal constraints, and causal and total ordering of messages. VCBP has been implemented and evaluated in a vehicular network simulation environment, and its
    performance has been compared with other protocols available in the literature. The results show that VCBP can provide enhanced message delivery guarantees with a message delivery rate similar to or better than other evaluated approaches.

4
  • Eber Chagas Santos
  • Multichannel Scheduling for Convergecasting in TSCH Networks

  • Advisor : FLAVIO MORAIS DE ASSIS SILVA
  • COMMITTEE MEMBERS :
  • FLAVIO MORAIS DE ASSIS SILVA
  • LEOBINO NASCIMENTO SAMPAIO
  • MARCELO SAMPAIO DE ALENCAR
  • Data: Oct 20, 2023


  • Show Abstract
  • This dissertation presents a multichannel algorithm for convergecast developed in the context of Industrial Wireless Sensor Networks. It calculates a convergence tree and a schedule for sending and receiving messages in Time Slotted Channel Hopping (TSCH) networks. To build the convergence tree, there is a prior creation of local trees. The routing protocol Routing Protocol for Low-Power and Lossy Network (RPL) was used in the attribution of ranks and in the process of connecting the nodes with the formation of a global tree. The algorithm works under the creation of a collision-free schedule, due to the use of a technique called Dilution. This is based on the fact that one or more nodes in relative positions of a plane can transmit messages in the same time interval without interference or loss of messages. The entire algorithm was developed under a real protocol stack that runs under the Cooja simulator contained in the Contiki-NG operating system. The simulator implements the Unit Disk Graph Medium (UDGM) interference model adopted in this work. It allows sensor nodes to communicate over a given transmission range r, which is a transmission range modeled as an ideal disk. As the Contiki-NG operating system offers reference implementations of the TSCH, it was decided to compare algorithms from that system with the one proposed in this dissertation. The implemented algorithm can generate schedules with a reduced slotframe size, even with a large number of sensor nodes in the network. Satisfactory results were also presented regarding the packet delivery rate and average delay time in the communication of the created convergecasts, surpassing some approaches that deal with the same metrics.

5
  • EZEQUIAS SANTOS DE MATOS
  • Data-driven economic real-time optimization of gas-lifted oil wells

  • Advisor : MARCIO ANDRE FERNANDES MARTINS
  • COMMITTEE MEMBERS :
  • GUILHERME AUGUSTO DE ALMEIDA GONÇALVEZ
  • MARCIO ANDRE FERNANDES MARTINS
  • OSCAR ALBERTO ZANABRIA SOTOMAYOR
  • Data: Nov 9, 2023


  • Show Abstract
  • In the present study, one addresses a daily dynamic optimization problem in oil production through a data-driven approach. To this end, the use of an artificial neural network (ANN) architecture is proposed as a substitute for the phenomenological model that represents the gas-assisted oil well production system. Therefore, it is crucial to include information on the oil flows from each well and also from the top of the riser. However, flow rate measurements are not available in real-time, and what is available is only the total flow rate after separation, which does not allow understanding the behavior of each well individually. Due to the unavailability of individual well flow measurement, the use of a mobile horizon estimator (MHE), supported by a phenomenological model, has proven to be an appropriate solution for estimating these variables, allowing for the provision of data for training and obtaining a substitute model to be used in the dynamic optimization stage. Thus, it was possible to enable the training of the Nonlinear Autoregressive with Exogenous Input (NARX) neural network architecture employed in this research. This choice was based on the finding that the network was able to conveniently predict one-step-ahead. The results obtained from the application of the proposed approach on a single well and on a field consisting of three wells and a riser demonstrated a good performance of the artificial neural network in terms of temporal prediction, in addition to a more efficient computational time in solving the optimization problem when compared to the standard phenomenological model. The solution proposed by this approach opens up several possibilities for implementation in large-scale problems, such as optimizing the daily production of an oilfield composed of multiple wells integrated by different reservoirs and manifolds.

6
  • RAFAEL SANTANA QUEIROZ
  • AN APPROACH BASED ON DEEP LEARNING AND MULTISENSORY DATA FUSION TO DETECT AND CLASSIFY DEFECTS IN VESSEL HULLS

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • HERMAN AUGUSTO LEPIKSON
  • IVAN COSTA DA SILVA
  • LEIZER SCHNITMAN
  • RODRIGO SANTIAGO COELHO
  • Data: Dec 11, 2023


  • Show Abstract
  • Inspecting vessel hulls requires using more than one non-destructive inspection technique to detect different defect types. Depending on the age and size of the inspected asset, a massive volume of inspection data can be generated, making the analysis laborious and susceptible to errors due to human fatigue.

    This work aims to present an approach to speed up the data analysis and reduce human errors through multisensory data fusion to detect and classify defects in vessel hulls. In order to validate the developed approach, an experiment is conducted in a controlled environment, in which a test plate is inspected by three systems of different physical natures: camera, magnetic eddy current, and ultrasound.

    The collected data from this experiment are used to develop three classifiers – each for a technique –, from which two are made based on artificial neural networks, given the complexity of the data. The classifiers are then fused at the decision level, generating an easy-to-interpret colored defect segmentation map, where each color represents a specific type of defect. Finally, a technical report model is also proposed containing information regarding each detection, such as type, location, and area, which can be helpful for structural health monitoring purposes.

    This work represents a step forward in the inspection technology of large structures by exploring the complementarity of multisensory systems. Although the strategy has been exemplified in a vessel inspection scenario, it applies to Other systems that inspect large areas. The fusion of classifiers represents time savings in analysis, reduction of operational costs, and increased safety through the mitigation of doubts regarding the classification of defects.

7
  • WALMIR RODRIGUES DA LUZ
  • Time series forecasting applied to performance indicators of a hot rolling process

  • Advisor : ANGELO MARCIO OLIVEIRA SANT ANNA
  • COMMITTEE MEMBERS :
  • EDUARDO ALVES PORTELA SANTOS
  • ANGELO MARCIO OLIVEIRA SANT ANNA
  • MAURICIO SANTANA LORDELO
  • Data: Dec 13, 2023


  • Show Abstract
  • Measuring a company's efficiency is fundamental for decision-making, influenced by the performance of its assets, including technology, industrial capacity, quantity of products and employee qualifications. The efficiency of production systems often depends on large volume production with little variety of products, which is directly linked to the efficiency of processes or bottlenecks. Applying demand forecasting models based on time series is an effective tool to obtain this information. However, to date, no studies have been found that applied these models in a hot rolling process, which raises the opportunity for investigation. The main objective of the dissertation is to develop a prediction model for performance indicators in a non-flat hot rolling process in a steel industry based on time series. The case study demonstrated how the global efficiency index factors impact the rolling process. The results indicated the ARIMA (2,0,2) model as the most appropriate, and its predictions revealed daily values of the OEE global efficiency index between 0.404 and 0.993. The results showed that the L2 Lamination process can work to achieve a challenging working range (0.699 < OEE ≤ 0.891), based on benchmarks from technical literature. The tool developed can be valuable for defining strategies and directing decision-making based on the insights provided by this forecasting model. The research demonstrated applying time series models in the steel industry contributes to management and efficiency improvement strategies.

8
  • ALAM ROSATO MACÊDO
  • QUASI-STATIC VEHICLE MODELING APPLIED TO THE PREDICTION OF MINIMUM LAP TIME

  • Advisor : MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • COMMITTEE MEMBERS :
  • GUSTAVO ARTUR DE ANDRADE
  • DANIEL DINIZ SANTANA
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • Data: Dec 22, 2023


  • Show Abstract
  • In this work, a new method for quasi-static modeling of competition vehicles was developed. The method uses only information that is readily available for amateur automotive competition categories. An optimization problem was formulated to determine the optimal trajectory and a new optimization method was developed to perform the trajectory optimization. This new method (Double Gradient Method) makes it possible to predict racing lines described by cubic splines (problems solved in most cases by stochastic methods) in a similar time as deterministic methods. Solving the minimum lap time problem using a graphical optimization method proved to be feasible and applicable. The double gradient method was evaluated against four other optimization methods capable of graphically optimizing the trajectory and was the only one that could run the simulation in a timely manner, allowing the analysis to be performed during sporting events.

Thesis
1
  • Marcelo Mendonça dos Santos
  • Introducing a self-supervised, superfeature-based network for video object segmentation

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • EDUARDO JOSÉ DA SILVA LUZ
  • GLADSTON JULIANO PRATES MOREIRA
  • LUCIANO REBOUCAS DE OLIVEIRA
  • RODRIGO TRIPODI CALUMBY
  • THIAGO OLIVEIRA DOS SANTOS
  • Data: Jun 9, 2023


  • Show Abstract
  • Video object segmentation (VOS) is a complex computer vision task that involves identifying and separating the pixels in a video sequence based on regions, which can be either the background or foreground of the scene or even specific objects within it. The task must be accomplished consistently throughout the sequence, ensuring that the same object or region receives the same label in all frames. Recent advances in deep learning techniques and high-definition datasets have led to significant progress in the VOS area. Modern methods can handle complex video scenarios, including multiple objects moving over dynamic backgrounds. However, these methods rely heavily on manually annotated datasets, which can be expensive and time-consuming to create. Alternatively, self-supervised methods have been proposed to eliminate the need for manual annotations during training. These methods utilize intrinsic properties of videos, such as the temporal coherence between frames, to generate a supervisory signal for training without human intervention. The downside is that self-supervised methods often demand extensive training data to effectively learn the VOS task without supervision. In this work, we propose Superfeatures in a Highly Compressed Latent Space (SHLS), a novel self-supervised VOS method that dispenses manual annotations while substantially reducing the demand for training data. Using a metric learning approach, SHLS combines superpixels and deep learning features, enabling us to learn the VOS task from a small dataset of unlabeled still images. Our solution is built upon Iterative over-Segmentation via Edge Clustering (ISEC), our efficient superpixel method that provides the same level of segmentation accuracy as top-performing superpixel algorithms while generating significantly fewer superpixels. This is especially useful for processing videos, where the number of pixels increases over time. Our proposed SHLS embeds convolutional features from the frame pixels into the corresponding superpixel areas, producing ultra-compact image representations called superfeatures. The superfeatures comprise a latent space where object information is efficiently stored, retrieved, and classified throughout the frame sequence. We conduct a series of experiments on the most popular VOS datasets and observe interesting results. Compared to state-of-the-art self-supervised methods, SHLS achieves the best performance on the single-object segmentation test of the DAVIS-2016 dataset and ranks in the top five on the DAVIS-2017 multi-object test. Remarkably, our method was trained with only 10,000 still images, outstanding from the other self-supervised methods, which require much larger video-based datasets. Overall, our proposed method represents a significant advancement in self-supervised VOS, offering an efficient and effective alternative to manual annotations and significantly reducing the demand for training data.

2
  • Lorena Leal de Oliveira Soares
  • High-Power Ultrasonic-Assisted Tool for Calcium Carbonate Scale Prevention

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • IURI MUNIZ PEPE
  • EDNILDO ANDRADE TORRES
  • GEYDISON GONZAGA DEMETINO
  • GERMANO PINTO GUEDES
  • DION BARBOSA DOS SANTOS RIBEIRO
  • Data: Aug 18, 2023


  • Show Abstract
  • The inorganic salts scale can cause several damages to the oil industry installations. They can occur in pipes and equipment and can cause reduction and even total blockage of the flow of fluids. Scales generate high maintenance and remediation costs. Calcium carbonate is one of the salts that most deposit and that is why several studies have been carried out to better understand the process of scales formation and deposition. One way to decrease fouling-related costs is prevention. For this there are several techniques that are already used in the industry, for example, chemical and physical inhibitors. This paper proposes a calcium carbonate scale physical inhibitor assisted by ultrasound. Two approaches have been taken: (i) bonded piezoelectric ceramics directly into a tube section and (ii) Langevin ultrasonic transducers coupled to a pipe section. Initially, an investigation was made of the piezoelectric ceramic use a coupled to a section external wall of pipeline filled with water. In this configuration, tests were carried out to determine pressure zones and conductivity with solutions of calcium chloride and sodium carbonate as precursors. Such tests were important for the study, as they showed: (i) the existence of acoustic pressure zones, confirming that there is ultrasonic action in the pipe section and (ii) the influence of ultrasound on calcium carbonate precipitation, by decreasing the induction time. Despite the low power used, ultrasound was able to promote the calcium carbonate crystals precipitation acceleration. In addition, assembled arrangement modeling and simulation were carried out in order to confirm the result obtained in the tests with piezoelectric ceramics glued to the tube wall. In the second approach, an ultrasonic tool was developed with Langevin-type transducers. Through modeling and simulation in the COMSOL Multiphysics® software, the configuration of 56 transducers distributed in groups of eight by seven steel rings was achieved, in a tube measuring one meter and 1 1/2” in diameter, Schedule pattern with 48.26 mm outside diameter. Tests were carried out with aluminum sheets and tests with calcium carbonate in the laboratory, for which the tool was assembled with three rings. The laboratory tests were carried out in the high-pressure line of the Interdisciplinary Center of Fluid Dynamics - NIDF, with initial pressures of 8 and 20 bar and final pressure of 80 bar. In addition to the pressure curve, the average particle size and the test specimen masses were measured. The material embedded in the specimens was analyzed using a scanning electron microscope (SEM). Despite the tool having been tested with three of the seven rings, the tests demonstrated that there is feasibility of using the tool in oil wells.

3
  • LEANDRO DO ROZARIO TEIXEIRA
  • Optical system for real-time monitoring of the free water content in diesel - Methodology applicable to storage tanks for by-products of the petroleum industry.

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • FELIPE PEREIRA FLEMING
  • HERMAN PESSOA LIMA JUNIOR
  • ANTONIO FERREIRA DA SILVA
  • GEYDISON GONZAGA DEMETINO
  • IURI MUNIZ PEPE
  • Data: Dec 15, 2023


  • Show Abstract
  • Products and byproducts derived from oil, such as diesel, can incorporate water during the production, transportation, and storage process, as well as the biodiesel present in diesel. The presence of water in these products has always been a problem for the industry, causing serious damage to the equipment where they will be used and contributing to corrosion in the tanks responsible for their storage. The water content in fuels can be classified into three categories: soluble water, emulsified water, and free water. Soluble water occurs when the portion of water is able to be dissolved in the fuel, depending on thermodynamic parameters, such as temperature, and the chemical composition of the same. Emulsified water is a mixture of water and diesel in which the water droplets are dispersed in a diesel matrix. The water droplets are so small that they do not sediment, but remain suspended in the diesel. Emulsified water can be formed at any process in the diesel production line. Free water occurs due to the difference in density between the fuel and water, producing a mixture of distinct and perfectly distinguished phases. This work deals with the development of a real-time monitoring and analysis methodology that will compose an engineering solution capable of identifying the presence of free water in storage tanks, making the proper disposal in an intelligent and autonomous way. For this purpose, a test bench was built that simulates the storage process of diesel/biodiesel, composed of: (i) storage tank, (ii) disposal tank, (iii) cleaning tank, (iv) instrumented optical unit operating in the near infrared and ultraviolet range, in addition to acquiring images, (v) electromechanical devices for controlling and actuating the operating modes of the developed plant, and (vi) expert software for controlling, acquiring, and analyzing the acquired data. The optical unit is capable of analyzing and classifying in real time the fluid present in storage tanks by near-infrared spectroscopy and UV spectrophotometry, as well as the use of computer vision techniques for fluid analysis through image recognition.

2022
Dissertations
1
  • LUCAS GOMES PEREIRA
  • Design and development of high volume photoreactor with luminous flux mapping
  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • DION BARBOSA DOS SANTOS RIBEIRO
  • IURI MUNIZ PEPE
  • MARCUS VINICIUS SANTOS DA SILVA
  • Data: Jan 11, 2022


  • Show Abstract
  • This work presents the design and development of photoreactors with their 
    luminous flux mapping. Photoreactors have been widely used in photocatalytic 
    degradations of different chemical agents. In combination with ultraviolet lamps, the 
    generated system is able to kill bacteria, help in the treatment of hospital effluents, 
    such as drugs, or pollutants. Knowledge about the light radiation field is rarely done. 
    The use of a sensor with phototransistors capable of capturing light sources in different 
    directions, as well as its calibration by an optical sensor for power measurements are 
    discussed. The simulation carried out in Ansys® software points to a uniformity of the 
    illumination field inside the device, although the intensity is greater as the simulation 
    approaches the center of the LEDs. The luminous flux mapping with the sensor shows 
    greater luminous intensity near the center of the LEDs. The main use expected of the 
    equipment produced is the excitation of petroleum asphaltenes.
2
  • LUCAS BARBOSA DA SILVA
  • Detector solar fly eye para estudo da irradiação eletromagnética

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • EDSON PEREIRA MARQUES FILHO
  • IURI MUNIZ PEPE
  • TIAGO FRANCA PAES
  • Data: Jan 21, 2022


  • Show Abstract
  • Over the last decade, the use of solar energy to generate electricity has shown
    increasing numbers.In general,solar-electric energy conversion systems are carried out
    by flat photovoltaic modules, previously installed, provided based on the local latitude
    of installation and in fixed structures. In this sense, the use of mobile structures or
    structures with different topology has enabled the increase in the production and study
    of solar energy.
    This dissertation revisited the literature on biomimetics, the sun as a source of
    energy and the different technologies used in the manufacture of solar cells, as well as
    their functioning, which contribute to a broader understanding of the constitution of this
    device.
    In order to contribute to research in photovoltaic energy and the study of solar
    irradiance, this work proposes a fly eye topology solar detector with the potential to
    measure local insolation. The equipment allows you to observe the dynamics of solar
    radiation during the different seasons of the year.
    Confrontations were established between the results obtained in this dissertation
    referring to the seasons of the year,in this way,to verify the average level of irradiance in
    each season and the relationship with the inclination angle of the solar cell in the device
    that were used as a radiation sensor.

3
  • Laís Bastos Pinheiro
  • Performance analysis of the Mask R-CNN network for numbering and segmenting teeth in panoramic radiographs

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • EDUARDO MANUEL DE FREITAS JORGE
  • LUCIANO REBOUCAS DE OLIVEIRA
  • PATRICIA RAMOS CURY
  • PAULO SERGIO FLORES CAMPOS
  • Data: Oct 7, 2022


  • Show Abstract
  • In dentistry, panoramic radiography is an important tool to assist dentists in their diagnoses, monitor oral health, and plan or monitor patient treatment. The large number of indications for use and their advantages of use have boosted studies on the application of deep learning techniques in this type of imaging exam. For the automatic analysis of panoramic radiography, the individual identification of teeth is an indispensable step, since detecting, numbering and segmenting teeth are essential tasks for later stages of automatic diagnosis of these radiographs and generation of automated reports. In this sense, this project proposes to automate the task of identification (detection, numbering and segmentation) of teeth, from the evaluation of neural networks based on deep learning, which delimit, label and segment each tooth detected in the panoramic radiograph. For the evaluation of the overall performance of neural networks, a comprehensive set of panoramic radiographs data with consistent annotations in the image of permanent and deciduous teeth was not found in the literature. To fill this gap, this work contributes an annotated dataset, consisting of the contour of each tooth and manual labeling of each tooth based on the FDI dental notation. This dataset is formatted by 450 images of panoramic radiographs. The notes were taken by dentistry and computer science students, with the help and supervision of professionals in the field of dentistry. From the database created, the proposal of this project is also to evaluate two neural network architectures based on Mask R-CNN: the standard network and another that adds the PointRend module in the segmentation branch. The best performance was achieved with the addition of the PointRend module, which reached 75.3% and 77.3% of mean average precision (mAP), in the numbering and segmentation tasks, respectively, surpassing the standard Mask R-CNN by 1, 2 and 2 percentage points. The aim of the investigation was to find a method that improves segmentation per instance at the limits of teeth, because this is the main obstacle of segmentation methods, which was achieved with the R-CNN Mask plus the PointRend module. It is expected that this study and the new public dataset represent an advance in the automatic processing of image exams in panoramic radiographs, encouraging the proposal of new algorithms to solve the proposed problem.

4
  • Antonio Ferreira de Oliveira Neto
  • Dynamic location system of spaces in covered parking lots

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • HERMAN AUGUSTO LEPIKSON
  • IURI MUNIZ PEPE
  • VALÉRIA LOUREIRO DA SILVA
  • Data: Dec 12, 2022


  • Show Abstract
  • Parking for the public in urban environments, such as large office complexes or shopping centers, becomes increasingly larger and more complex to meet the needs of its users. Navigating and locating these environments are a recurring problem faced by drivers, either to locate a vacancy or to find the parked vehicle. Efforts to improve this uncomfortable situation have been made, but the biggest problem for guiding drivers lies in covered and closed parking lots, where geolocator signs do not arrive. Currently, a significant number of systems for guidance in parking lots in covered environments performs the location and signaling to park in available spaces, generally based on systems to indicate regions with available spaces and light signals. However, integration between systems that allow to assist more effectively the location of spaces and, in addition, as they link to vehicles once parked in order to help the driver locate his vehicle when coming back. The present work uses an IoT-based approach to build an effective system for locating and identifying, in real time, covered parking spaces without relying on external signage and associating space with the specific vehicle in order to facilitate its location upon the driver's return. The developed system makes use of fusion mechanisms of properly indexed sensors, a communication system suitable for the specific environment, in this case, covered parking lots, including computer systems able to treat and interpret data and interface with users that facilitate the management and tracking of vacancies in a covered environment.

Thesis
1
  • Galdir Damasceno Reges Junior
  • Estimation of vibration amplitude of rotating machines

  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • LEIZER SCHNITMAN
  • ANTONIO CEZAR DE CASTRO LIMA
  • MARCOS PELLEGRINI RIBEIRO
  • JANITO VAQUEIRO FERREIRA
  • LUIS ANTÔNIO AGUIRRE
  • Data: Feb 17, 2022


  • Show Abstract
  • This thesis addresses vibration amplitude estimation errors in rotating machines due to the elliptical shape of the vibration orbits and the operating frequency variation and proposes a methodology to reduce these errors. Rotating machines can have high acquisition, installation, and intervention costs in industrial production, especially in oil production in subsea wells. This is the case of the Submerged Centrifugal Pumping system (BCS), the second most used method of artificial lifting of oil in the world. The BCS system is applied to pump large volumes at high pressure and has higher costs than alternative methods. Vibration analysis of these machines is carried out for approval or rejection of the equipment before installation, thus seeking to reduce the risk of significant financial losses. The vibration analysis process for approval before installation is done by comparing the estimated vibration amplitudes with vibration limits established in standardized vibration severity standards. The estimation of industrial vibration amplitude is typically done using the discrete Fourier transform (DFT). The DFT has widely known properties that can lead to estimation errors that can be mitigated by different techniques to ensure the estimate's accuracy. However, at least two other sources of errors are overlooked and can lead to uncertainty in estimates and financial losses. The first source concerns the vibration measurement not necessarily occurring in the orientation that presents the higher radial vibration. As the vibration orbit can occur in an elliptical shape, and this shape can vary during operation, the installed vibration sensors will not necessarily be oriented towards the ellipse's major axis. The second source of errors comes from the fact that rotating machines are subject to minor speed variations that can lead to amplitude estimation errors due to the specialization of the analysis methods in stationary signals. There are techniques to reduce both estimation errors; however, these techniques are complex and imprecise to deal with vibration signals with the noise level and speed variation typical of BCS-type rotating machines. The methods currently found in the state of the art for vibration orbit analysis are significantly different from the individual signal frequency spectrum and can be considered counterintuitive. Their results cannot be directly compared to standard vibration limits for rotating machines. On the other hand, the methods found for accurate estimation of amplitude with frequency variation: either are dependent on the installation of a tachometer, which is not feasible in installations of some machines such as the complete assembly of BCS systems; or are dependent on the instantaneous velocity estimate, which is subject to more uncertainty; or they are imprecise with the noise level and frequency variation found in BCS systems, as demonstrated in this Thesis. This thesis presents a methodology for estimating the vibration amplitude of rotating machines, invariant to the shape of the vibration orbit and robust to variations in speed and presence of noise. The methodology involves the proposition of two methods: the Orbit Semi-major Axis Spectrum for estimating the spectrum invariant to the elliptical shape of the vibration orbits; and the EHRS method to perform the vibration amplitude estimation with robustness to the presence of noise and variation of speed, without depending on the instantaneous frequency as is necessary for other methods. To demonstrate its efficiency, the methodology proposed in this thesis was compared with typical methods of amplitude estimation on vibration signals from rotating machines of Submerged Centrifugal Pumping (BCS) systems. Evaluations were performed with simulated and experimental signals of vibration orbits of BCS systems. Analysis of simulated signals can allow the calculation of the estimation error because the generated amplitude value is known. On the other hand, it is impossible to know the correct amplitude in the analysis of experimental signals. However, it is possible to demonstrate that the differences in vibration amplitude between the evaluated methods follow the pattern of the simulated signals. The performance evaluation results showed that the proposed methodology, using the proposed methods EHRS and Semi-Major Axis Orbit Spectrum, is invariant to the shape of the vibration orbit, has greater robustness to frequency variation and the presence of noise than the other methods evaluated, and is recommended for the analysis of vibration amplitude of rotating machines.

2
  • CARLOS EDUARDO TANAJURA DA SILVA
  • High power ultrasonic reactor applied in the oil and gas industry.

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • ANDRÉ LEIBSOHN MARTINS
  • ACBAL RUCAS ANDRADE ACHY
  • GEYDISON GONZAGA DEMETINO
  • IURI MUNIZ PEPE
  • TIAGO FRANCA PAES
  • VICTOR MANCIR DA SILVA SANTANA
  • Data: Sep 8, 2022


  • Show Abstract
  • In the oil and gas industry, in offshore and inshore applications, it is of fundamental importance to combat the phenomena and/or effects that affect the oil exploration and production process. High power ultrasound can be of great value to researching solutions and developing the industrial and technological sector as it is an excellent solution to combat carbonation in pipelines, accelerating the precipitation of particles during the flow of oil. This thesis work proposes a high-power ultrasonic reactor as an active mechanism in the precipitation of calcium carbonate. Ultrasound delays the nucleation of crystals, making it difficult for particles to join during flow. Therefore, there will be a lot of smaller particles closer to the ultrasonic reactor compared to other regions along the pipeline. In this work, he shows the laboratory tests for the development and calibration of the ultrasonic reactor, the distribution of the ultrasonic field and how regions of higher ultrasonic pressure from a simulation software. It is also presented a proposal for an experiment carried out in Rio de Janeiro, at NIDF - Interdisciplinary Nucleus of Fluid Dynamics, in the multipurpose line of studies of calcium carbonate. The tests showed relevant results in reducing the size of the carbonate crystals and the pressure in the completion valve remained practically stable up to 0.107 bar up to 120 minutes.

3
  • ALEXANDRE ARARIPE CAVALCANTE
  • Relationship between 3D printing parameters and the anisotropic mechanical strength of PLA printed parts

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • IURI MUNIZ PEPE
  • HERMAN AUGUSTO LEPIKSON
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • JOSE GARCIA VIVAS MIRANDA
  • ANTONIO FERREIRA DA SILVA
  • Data: Sep 20, 2022


  • Show Abstract
  • A Fabricação por Filamento Fundido (FFF – Fused Filament Fabrication), mais conhecida por FDM© (Fused Deposition Manufacturing) é um processo de manufatura aditiva (AM) pelo qual um objeto físico pode ser criado, a partir de um modelo em 3D gerado no computador, através da deposição camada a camada de filamentos plástico semiderretidos. Por ser um processo eficiente, durável e de baixo custo, permitindo a prototipagem rápida de modelos e reduzindo a relação de custo e tempo de projeto, vem sendo largamente usada na indústria para protótipos funcionais e baixos volumes de produção, sendo que, desde a queda das patentes originais dos processos de FDM, um grande número de impressoras 3D tem surgido no mercado de consumo, tornando essa tecnologia de fácil acesso e cada vez mais popular. Entretanto, as peças produzidas pelo processo de FDM possuem características diferentes das peças produzidas por métodos tradicionais como a injeção de plástico, especialmente no que tange a propriedades mecânicas relacionadas a tensões (tração, compressão, torção e cisalhamento) devido à natureza anisotrópica do processo de deposição. Por isso, torna-se importante identificar e caracterizar as propriedades do processo que tem maior influência nas propriedades mecânica das peças fabricadas for FDM. Muitos trabalhos têm sido realizados no sentido de determinar a influência entre os parâmetros do processo de FDM e as características mecânicas de peças produzidas por essa tecnologia, mas a grande maioria deles analisam a resistência longitudinal causada pelo sentido e orientação de deposição dos fios semiderretidos. Os poucos trabalhos que abordam a anisotropia transversal geralmente o fazem simulando essa anisotropia com espécimes impressos na horizontal e contemplam testes usando ABS, um plástico de uso muito comum pela indústria. De uns poucos anos para cá, um novo plástico, o PLA, começou a se expandir como material usado nas impressoras 3D, especialmente as impressoras de uso não industrial, por ser biodegradável e possuir outras características que o tornam mais popular. Este trabalho estudou as relações entre as propriedades de deposição (como preenchimento, altura da camada, temperatura) com a resistência mecânica para cargas de tração no sentido longitudinal de impressão das peças impressas, determinando a contribuição desses parâmetros e propondo um modelo matemático para prever a resistência baseada na geometria de uma peça, permitindo a inclusão de parâmetros de impressão na modelagem da mesma. Os ensaios de tração foram realizados em uma máquina de teste construída especialmente para essa pesquisa. Para determinar os ensaios experimentais usamos a metodologia DOE fatorial (Design of Experiment) para minimizar a quantidade de experimentos. Usando a análise de variância (ANOVA) e o método Taguchi de análise dos resultados, identificamos a Área de Contato entre as espiras como o parâmetro mais relevante na resistência à tração no sentido transversal de impressão, com uma relevância de mais de 95% sobre os outros parâmetros estudados. A partir do levantamento das propriedades relevantes, novos ensaios foram realizados para determinar a solução de compromisso entre esses parâmetros e a resistência mecânica de peças fabricadas por FDM em PLA, sugerindo uma metodologia para reduzir a fragilidade das peças devido à anisotropia transversal.  

2021
Dissertations
1
  • NEI DA SILVA PAZ NETO
  • 4 Axis CNC Machine for Making Dental Prostheses.

     
     
     
     
     
     
  • Advisor : MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • COMMITTEE MEMBERS :
  • FABIOLA BASTOS DE CARVALHO
  • HERMAN AUGUSTO LEPIKSON
  • IURI MUNIZ PEPE
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • Data: Feb 25, 2021


  • Show Abstract
  • CAD / CAM (Computer Aided Design) and Computer Aided Manufacturing (Computer Aided Manufacturing) technology has been widely applied in laboratories and specialized clinics in the field of restorative dentistry. Since the 1970s, studies and advances in technology have been carried out with a view to improving the final quality and precision of restorations. However, most of the systems available on the market are closed and expensive technologies. The systems have a high cost of application since they bring less process time, quality and precision to the production, therefore, not all professionals and students can have access to this technology, in addition, not all people who need a prosthesis dentistry will receive a restoration with the quality and precision characteristic of these systems, thus opting for manual production processes with reduced costs. This dissertation demonstrates the development of a four axis CNC (Computerized Numerical Command) milling machine with low development cost that has the objective of machining dental restorations. The proposed machine aims to instigate studies and research on mechatronic systems applied to dentistry and to assist the teaching and development of future professionals in the field.

     
     
     
     
     
     
2
  • LUCLECIA CAMPOS SILVA
  • Evaluation of economic benefit obtained by using real-time optimization software in refineries using statistical inference

  • Advisor : MARCIO ANDRE FERNANDES MARTINS
  • COMMITTEE MEMBERS :
  • MARCIO ANDRE FERNANDES MARTINS
  • ADONIAS MAGDIEL SILVA FERREIRA
  • ANTONIO CARLOS ZANIN
  • Data: Mar 10, 2021


  • Show Abstract
  • The use of real-time optimization (in English, Real-Time Optimization - RTO) is a consolidated technology in the refining and petrochemical industry due to the increase in economic performance that it inserts in the units when determining its optimum point online. Although automated, the effective operation of such systems requires a continuous effort by the operation and engineering teams, making it essential to monitor the benefits achieved. This work proposes a new methodology for calculating this gain, which will be expressed through a linear regression model, obtained by the LASSO statistical learning method. The entire development of this work revolves around the delta-profit variable, which is the economic benefit generated by each execution of the optimizer, investigating its practical meaning and specificities for using this information in order to gauge the real gains obtained. To this end, the work was divided into three parts. (i) Overview of the delta-profit response variable of seven RTO applications installed in some Brazilian refineries; next, a RTO installed in a distillation unit is taken for a case study to: (ii) propose a linear regression model to identify the variables influencing this response, using real operational data from an RTO application; and finally; (iii) proposing a model for online monitoring of the economic, potential and obtained benefit, using a database generated through offline executions of the optimizer. The use of online data to estimate the model is facilitated because the information is available, it is enough to structure it to form the database. Considering the complex and multiple nature of these systems, this alternative is promising and can be automated to support the investigative activity. The use of offline data, in turn, requires more time from the analyst to manually perform the simulation and generate a sufficient number of observations, but it proved to be the most reliable way to estimate the potential gain. Instead of an average of the benefit in different conditions, the use of a regression equation allows to estimate the benefit in the real conditions in which the RTO is submitted, a differential of this work.

3
  • João Ricardo de Oliveira Mota
  • Deerministic Convergecast for Industrial Wireless Networks

  • Advisor : FLAVIO MORAIS DE ASSIS SILVA
  • COMMITTEE MEMBERS :
  • IVAN MUELLER
  • ALLAN EDGARD SILVA FREITAS
  • FLAVIO MORAIS DE ASSIS SILVA
  • Data: Aug 10, 2021


  • Show Abstract
  • This dissertation describes a deterministic convergecast algorithm implemented in a 6TiSCH protocol stack. Convergecast is a method of passing messages in which all nodes in a network transmit messages to a root node. The developed algorithm uses a scheduling technique called dilution, to elect leaders and to build a convergecast tree. This technique is based on the concept that nodes distant from each other (by at least a certain distance) can transmit simultaneously, without interference in communication or loss of messages in their proximity (within a certain range). To schedule these messages, the execution synchroniicty provided by the TSCH protocol is used. This project was developed for the Contiki-NG operating system and therefore uses a real protocol stack. The results of the simulations yielded a practically perfect performance in the ability of the convergecast algorithm to avoid message losses, even with all nodes transmitting at every possible opportunity, and maintaining a message transmission rate, depending on the network density, above 40 messages per minute for each node.

4
  • DENISE GOMES DE CASTRO
  • Protocol for Nonlinear Analysis of Human Balance

  • Advisor : FLAVIO MORAIS DE ASSIS SILVA
  • COMMITTEE MEMBERS :
  • ANA LUCIA BARBOSA GOES
  • CRISTIANO SENA DA CONCEICAO
  • FLAVIO MORAIS DE ASSIS SILVA
  • JOSE GARCIA VIVAS MIRANDA
  • Data: Aug 17, 2021


  • Show Abstract
  • Human balance creates stability and creates conditions for other movements to be carried out. Emerging from the interaction of several body systems, balance continually genera- tes small postural oscillations that may indicate health conditions. Postural oscillations have a complex geometric pattern and, for their analysis, fractal methods have been used. Fractals are fractured geometric structures composed of patterns that are repeated on at least two levels of scale. Fractal methods produce direct qualitative and quantitative cha- racteristics of movement and assess sensorimotor impairment. However, a large number of methods and the diversity of measurement instruments have been generating different interpretations in the clinical area, making it difficult to create reference values. This work aimed to propose and validate a protocol for fractal analysis of human balance. Considering postural oscillation as a bivariate distribution, distributed in the anterior- posterior and medial-lateral coordinates, the protocol developed is an optical-electronic system. To capture data in these two coordinates, the Computational Vision Mobility software version 3.6 was used and the box count dimension method with the algorithm described by Higuchi to estimate the fractal dimension of the postural oscillation in the considered directions. The protocol was validated by investigating the postural oscilla- tion of 45 individuals, 23 young adults and 22 mature adults, and comparing the results obtained with the results of authors who used the box count dimension method, especi- ally the Higuchi algorithm. Thus, the proposed protocol is an objective analysis system of postural oscillation in healthy individuals that provides reliable and more in-depth in- formation on postural oscillations. Also, the protocol is portable, non-intrusive, occupies little space, and is easy to operate, with different ways of assembling the components allowing a better adaptation to the installed location.

5
  • MATHEUS ANTÔNIO NOGUEIRA DE ANDRADE
  • A MODULAR, SCALABLE AND GENERALIZABLE METHOD FOR CREATING DIGITAL TWINS OF INDUSTRIAL PROCESSES

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • DIEGO CORDEIRO BARBOZA
  • ALIRIO SANTOS DE SA
  • BRUNA APARECIDA SOUZA MACHADO
  • HERMAN AUGUSTO LEPIKSON
  • INGRID WINKLER
  • Data: Nov 30, 2021


  • Show Abstract
  • Digital twins are commonly referred as virtual copies of a physical asset. However, there is no common definition for this term that is widely adopted. Along with other terms in the context of Industry 4.0, digital twins are increasingly being discussed. It is noteworthy that the creation and development of a digital twin is dependent on the physical counterpart being mirrored. Products, services, industrial processes and physical phenomena are some of the instances that can be digitized for various purposes such as optimization, lifecycle management and performance analysis. The need to develop generalizable and scalable solutions for digital twins is increasing. Therefore, this work proposes a modular, scalable and generalizable framework for digital twin creation based on the concept of multi-agent systems to support processes with various specificities of different industries in a configurable constructive structure. Five classes of containers were used in this work: sensor, actuator, conveyor, operator and storage modules. These modules were designed to cover all kinds of entities present in an industrial process. The digital twin of an essential oil steam distillation plant was created to demonstrate the proposed methodology as an instance of validation of the proposed creation method. Distillation is carried out in batches with discrete batches of plant material. As it is a batch process, it presents both continuous and discrete dynamics. So, this process is a good demonstration of a generic digital twin. The proposed digital twin concept can be the basis for the creation of several others due to its modular, scalable and generalizable characteristics.

6
  • MÁRIO AUGUSTO SANTANA DE OLIVEIRA JÚNIOR
  • Deployment of blockchain technology to increase the trust of information flows in the construction industry.
  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • HERMAN AUGUSTO LEPIKSON
  • ALIRIO SANTOS DE SA
  • FABIOLA GONCALVES PEREIRA GREVE
  • Data: Dec 2, 2021


  • Show Abstract
  • Civil construction faces major problems regarding workflow traceability, and tracking services execution in ongoing construction is one of the most important among all of them once this activity is prone to failure, misinterpretation, and conflicts of interest. That happens because of the delay in applying new technologies, in addition to current technologies limitations to raise the level of confidence in this activity. From this point, this work aims to present blockchain smart contracts as a reliable digital alternative to enable improvement in workflow traceability. A smart contract can be defined as a programmed contract to automatically run some specific business conditions without the need of other parties’ supervision. In order to implement blockchain technology, it was performed a conceptual analysis on civil construction contracts that also covered blockchain technology. Then, a case study was carried out at the Superintendence of Public Works in Salvador through a smart contract application which was structured by the existing workflow. This case study made it possible to carry out the proof of concept validation tests by verifying the contract requirements fulfillment through algorithms, in addition it was possible to track the entire workflow. Lastly, this application aims to make processes more efficient, transparent and reliable by eliminating the risks of errors, default and misuse of resources.

7
  • MARIA CLARA ADERNE DOS SANTOS
  • A membership algorithm for the Partitioned Synchronous Distributed Systems Model (SPA)

  • Advisor : SERGIO GORENDER
  • COMMITTEE MEMBERS :
  • ALIRIO SANTOS DE SA
  • SANDRO SANTOS ANDRADE
  • SERGIO GORENDER
  • Data: Dec 16, 2021


  • Show Abstract
  • With the insertion of the Internet of Things concept in the industrial context, challenges related to distributed 
    automation systems have arisen, including with regard to communication, which is the main core of the performance 
    of these systems. Possible solution paths for communication can mitigate the obstacles encountered. In computational 
    terms, today's distributed automation systems resemble hybrid systems such as the partitioned synchronous 
    distributed systems model, SPA. Membership services manage communication groups between processes belonging 
    to a system and, together with a multicast service, form a group communication service that is a building block of 
    fault-tolerant distributed systems. In this sense, this dissertation introduces a membership algorithm for the SPA 
    model capable of managing multiple groups of processes and which has in its structure defect detection services 
    based on a perfect defect detector P; and consensus available for the SPA. The formally proven properties of the 
    algorithm were presented, as well as the elements of its simulation and evaluation, developed in a framework for 
    simulation and evaluation of distributed systems, HDDSS.
Thesis
1
  • NILMAR DE SOUZA
  • Determination of water flow using a non-invasive acoustic sensor for residential applications.


  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • CRISTIANO HORA DE OLIVEIRA FONTES
  • EDUARDO FURTADO DE SIMAS FILHO
  • MARCIO FONTANA
  • GERMANO CRISPIM VASCONCELOS
  • IGOR DANTAS DOS SANTOS MIRANDA
  • Data: Feb 5, 2021


  • Show Abstract
  • The present work presents the development of a non-invasive flow measurement system that makes it possible to monitor the use of water in homes to assess the consumption profile using acoustic analysis of the flow noise in a concentrated pressure loss element. For that, it was necessary to carry out a bibliographic survey of the existing devices, as well as the theory that underlies the principle of the system's operation, then experimental plants were set up in which the hypothesis was tested and experiments were carried out in homes. In order to carry out a coherent and replicable analysis, three headphones were tested and a compact and non-invasive system sensitive to the stimulus promoted by the flow in the proposed working range was developed. Aiming at physical robustness and cost reduction per unit, a wireless acquisition system based on microcontrollers with integrated transceivers was developed. In addition to the measurement system, it was necessary to develop a methodology for data collection and propose flow estimation techniques based on the audios captured with the acoustic sensor. From the experiments, it was possible to identify a model to relate the acoustic noise with the flow. The developed system provided the flow measurement in residential applications, and it is proposed to use this system to assist in the conscious consumption of water resources.

2
  • MARCIO FREIRE CRUZ
  • KINEMATIC APPROACH APPLIED TO ARTIFICIAL NEURAL NETWORKS FOR EARLY SEPSIS DETECTION

  • Advisor : CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • COMMITTEE MEMBERS :
  • ADONIAS MAGDIEL SILVA FERREIRA
  • ANGELO AMANCIO DUARTE
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • CRISTIANO HORA DE OLIVEIRA FONTES
  • NIVALDO MENEZES FILGUEIRAS FI
  • Data: Dec 8, 2021


  • Show Abstract
  • Sepsis is a severe disease that affects millions of people around the world, and its early detection is fundamental to improve the treatment effectiveness. Recently, several models have been proposed to classify sepsis-positive patients in advance or to identify the probability of the disease occurrence in the future. In both cases, the data input is usually composed of time series of vital signs or other clinical variables. The current research shows an innovative approach for early detection of sepsis by representing a patient as a moving particle in an N-dimensional space, where N is the number of the adopted vital signs. A Sepsis Point is established, which corresponds to the position occupied by a patient if he became positive for the disease. The position, velocity, and acceleration vectors of the patients relative to the Sepsis Point are calculated. These vectors are used to generate the Kinematic Variables, which are imputed in artificial neural network models for early detection of sepsis. The accuracies achieved by the Kinematic Approach were compared to the accuracies achieved by the same models using traditional vital signs as input. It was discovered that the Kinematic Approach resulted in greater accuracy models, proving this research’s hypothesis. Thus, the Kinematic Approach is expected to open new approaches for developing more accurate early detection sepsis models.

2020
Dissertations
1
  • EVILAZIO COELHO SOARES
  • MODELING AND SIMULATION OF AN ULTRASOUND TRANSDUCER INSTALLED AS A MAINTENANCE TOOL FOR PETROLEUM TRANSPORT LINES

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • ANA ISABELA ARAUJO CUNHA
  • IURI MUNIZ PEPE
  • LUIZ CARLOS SIMOES SOARES JUNIOR
  • MARCIO FONTANA
  • Data: Mar 19, 2020


  • Show Abstract
  • In the oil and gas industry, incrustation and deposition are a recurring problem, leading to losses in productivity, and augmentation of maintenance costs. The piezoelectric ultrasonic transducer is a device used by the oil industry as a solution. The task is to clean the oil transport ducts. The Laboratório de Propriedades Óticas (LaPO) of the Instituto de Física of UFBA has several research projects that addresses the use of commercial ultrasound piezoelectric transducers. The aim of this work is to develop a mathematical representation of a Langevin piezoelectric transducer for application in pipelines. A mathematical model of the electromechanical and mechanical components of the transducer has been developed. This model was used to understand the transducer physical and geometric parameters. The Matlab platform was used to perform the simulations, thus determining the resonant frequency and the maximum transducer displacement. Based on the developed mathematical model, one type of transducer has been fabricated, flanged. The prototype was characterized and analyzed. The resonance frequencies obtained by the model and experimentally resulted in a discrepancy of 4,3%.

2
  • BRUNO AGUIAR SANTANA
  • Predictive control with guaranteed stability and feasibility in embedded systems

  • Advisor : MARCIO ANDRE FERNANDES MARTINS
  • COMMITTEE MEMBERS :
  • DANIEL MARTINS LIMA
  • THIAGO PEREIRA DAS CHAGAS
  • TITO LUIS MAIA SANTOS
  • Data: Mar 20, 2020


  • Show Abstract
  • Model-based predictive control (MPC) refers to a class of advanced control strategies, which has been widely used in the process industry through distributed system architectures. With advances in hardware optimization and development techniques, MPC implementations in embedded systems have become intensive, however, important properties, such as ensuring stability and feasibility, still represent an open problem for real-time applications. . This work presents the implementation in embedded systems of a predictive controller with guaranteed nominal stability and feasibility, whose formulation results in a quadratic programming (QP) problem. The efficient ADMM (Alternating Direction Method of Multipliers) optimization technique was used to solve the QP, providing a sufficiently accurate solution in a few iterations. For that, o ine simulations were performed to properly tune the parameters of the controller and ADMM. The control of a fast dynamic electromechanical system was implemented in a CompactLogix L32E programmable logic controller (PLC), whose limited memory and processing resources impose challenges for the application, and in an ESP32 microcontroller, which has high processing power and memory. The results include hardware-in-the-loop simulations and experimental tests at the plant. The implementation in the PLC demanded about 40% of the total available memory and the computation time of the problem was approximately 90 milliseconds. On the other hand, in the microcontroller, only 18% of the total available memory was used, while the computation time of the problem was approximately 5 milliseconds. The results show the effectiveness of the controller in both hardware for the case of reference tracking, even in the face of model uncertainties. However, in large problems or where ADMM requires a greater number of iterations, the application may require more advanced features than those available on conventional PLCs.

3
  • JULIANA DE SANTANA SILVA
  • A Systemic, Adaptive and Experimental Approach Applied to Learning Courses with Technological Foundations

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • FLAVIO MORAIS DE ASSIS SILVA
  • HERMAN AUGUSTO LEPIKSON
  • ARMANDO SA RIBEIRO JUNIOR
  • CAMILA DE SOUSA PEREIRA-GUIZZO
  • Data: Mar 25, 2020


  • Show Abstract
  • Disruptive technological concepts have modified and created needs in the most diverse sectors of society. The nature of production and service systems has become increasingly collaborative between humans and machines, flexible and based on multidisciplinary processes. As a consequence, borders have been reduced, enabling the structuring of society, educational institutions, work environments and professionals in a complex and dynamic network. Thus, training professionals capable of reprogramming their skills in order to adapt to these environments becomes one of the main current challenges. In reaction, new educational models, supported by intelligent environments, based on the management of several active methods have been conceived. Another support for learning environments that has become more and more widespread are the adaptive learning methods, which are systems supported by computational techniques that adapt content, time and learning path to the individual needs of students. However, there is a need for learning management geared to new demands from different origins, those associated with the unfolding of technological changes in social environments and work organization. The problems of conceiving learning models adaptable to social, market and student needs can, under certain context boundaries, be considered as problems of managing demands in complex, dynamic environments with adaptive capacities. Thus, this study conceived a demand management approach based on the Theory of Complex Adaptive Systems, called Systemic, Adaptive and Experimental Management - GSAE that comprises a model of environment and generic processes that integrated provide means to (i) identify demands, origins and how they can be integrated into the environment; (ii) understand the consequences in the environment when a demand loses its degree of importance or ceases to exist; (iii) analyzing and making decisions based on multicriteria such as minimizing costs and maximizing benefits. It should be noted that the approach was applied in the management of the main elements of active teaching, the learning objectives structured in competences, the problem of learning and the evaluation of learning developed in a public university in architecture and engineering courses. As a result, GSAE proved to be efficient, effective and effective in the management of these elements, enabling the discovery of new characteristics of problems and attributes of teams in order to adapt the process to the implementation environment as well as the design of a dynamic learning evaluation model

4
  • JORSIELE DAMASCENO CERQUEIRA
  • OPTICAL DETECTOR FOR IDENTIFICATION OF WATER ADULTERATION IN AUTOMOTIVE NITROGEN LIQUID LIQUID REDUCING AGENT (ARLA 32)

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • DION BARBOSA DOS SANTOS RIBEIRO
  • IURI MUNIZ PEPE
  • VALÉRIA LOUREIRO DA SILVA
  • VITOR PINHEIRO FERREIRA
  • Data: Apr 24, 2020


  • Show Abstract
  • The Automotive Liquid Reducing Agent, known as ARLA 32 (aqueous solution containing 32.5% urea) is injected into the exhaust gas flow of Diesel vehicles that have Selective Reduction Catalyst (SCR) to reduce emissions of nitrogen oxides ( NOx). As a guarantee of effectiveness in reducing NOx and that the SCR is not deteriorated, it is essential to control the chemical composition of the ARLA. Adulteration of this compound by dilution in water has often been found, due to the high availability and low cost of the diluent element. This work proposes a new optical detector for in situ analysis of ARLA 32 adulterated with water in fuel stations, through spectroscopy in the near infrared. The preliminary tests carried out used a commercial LED in the near infrared (1050 nm, 1300 nm and 1450 nm) and a silicon photodetector, with a non-linear behavior of the transmitted radiation in relation to the water concentration. Thus, a dedicated spectrometer prototype was developed, using a wavelength of 1650 nm, in addition to the implementation of the InGaAs photodetector and a pulsating feeder circuit through a quartz crystal. A precision voltmeter with 0.1 mV resolution (display) was incorporated to read the measurements. Offset and sensitivity adjustment buttons were also implemented to calibrate the optical instrumentation. ARLA samples adulterated with specific percentages of water concentration were tested, showing the direct relationship of adulteration with the concentration of water in the sample and its molar absorptivity. Additional tests were carried out aiming at validating the equipment in the detection of adulterations. Thus, bulk ARLA samples collected from 5 different filling stations in the Metropolitan Region of Salvador were investigated for water adulteration. Urea values above 32.5% were found in all analyzed samples, which can be justified by the evaporation of demineralized water during storage. The results confirmed that the portable prototype developed for field measurement of ARLA samples at fuel stations, presents a quick analysis to identify and quantify the ARLA adulteration with water, and an affordable cost to provide diesel vehicle owners and inspection agencies with an innovative alternative for quality control of ARLA 32.

5
  • PAULO RENATO CAMERA DA SILVA
  • Technology Based Mobile Asset Monitoring System LPWAN
  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • HERMAN AUGUSTO LEPIKSON
  • FLAVIO MORAIS DE ASSIS SILVA
  • JOSÉ VALENTIM DOS SANTOS FILHO
  • Data: Jul 13, 2020


  • Show Abstract
  • The monitoring of assets is an increasingly present demand due to the potential of results presented in relevant issues such as reliability of operations, security, monitoring of the life cycle and cost reduction. A specific situation that requires attention is the monitoring of assets that circulate in uncontrolled environments, as is the case of vehicles, a typical case of assets that circulate in environments where the usual communication resources are not available, not allowing adequate tracking and In real time. Vehicles are interesting cases of assets that require specific tracking characteristics, since the information obtained allows the management of an entire fleet. Based on tracking, it is possible to better manage costs, evaluate performance on the routes followed, or act in emergency situations, such as in the case of theft or accidents. Currently, companies that provide vehicle monitoring services use only one form of data communication (GSM / GPRS), limited to the availability of specific networks in the cellular communication band. New emerging communication technologies have great potential to complement those existing in the expansion of the coverage area and with an important reduction in operating costs. The present work seeks to contribute to solving the problem of monitoring high-value and high-cost operating assets, such as vehicles, which circulate in uncontrolled environments, ensuring their proper use by accredited and authorized operators. An Internet of Things (IoT - Internet of Things) -based system that meets fleet monitoring requirements is developed. The system created aims to provide accurate vehicle monitoring data over a wireless network at low cost, using geolocation systems and some sensors to monitor the vehicle and proposing an architecture that communicates passively and actively to depend on the situation.


6
  • LEANDRO ESTRELA BRANCO
  • DMT: A low-cost thermographic mechatronic device.
  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • LUCIANO REBOUCAS DE OLIVEIRA
  • KARCIUS DAY ROSARIO ASSIS
  • ALEXANDRE DA COSTA E SILVA FRANCO
  • Data: Sep 14, 2020


  • Show Abstract
  • Thermography is a technique for graphically recording the temperatures of a body, with the intention of distinguishing areas with different temperatures. Bodies with temperatures above -273C (absolute zero on the Kelvin scale) are capable of emitting infrared radiation. This characteristic allows to study the behavior of the temperature in different objects, structures and surfaces over time. Applications involving thermography cover the areas of security and military applications, being used in border surveillance, search and rescue, maritime patrols and coastal surveillance, wildlife; through studies related to understanding the thermal physiology of animals; care related to health and veterinary medicine; involving the diagnosis of various diseases, work-related injuries, studies of behaviors and diagnoses in animals; and the engineering area, being applied in inspections of electrical and mechanical equipment, inspections of buildings, conformities in air conditioning systems, management and maintenance of installations; this is not an exhaustive list. The biggest limitation for the development of studies and applications involving thermography is related to the high cost of your equipment. Pocket thermal cameras like Fluke PTi120 and FLIR C2 cost an average of R $ 6,000.00 and R $ 3,000.00 respectively. Thermal cameras with additional technologies and features like the FLIR T1020 HD and Fluke TiX 580 cost on average US $ 41,500.00 and US $ 14,000.00, respectively. The price variation is related to the application that the equipment will have, its accuracy, camera resolution, sensor resolution, temperature measurement limits and embedded technologies produced by each manufacturer. In this sense, the proposal of this project is to present the development of a low cost mechatronic thermographic device (DMT) responsible for the production of thermal images of objects, covering the stages of construction of the physical structure, data acquisition, movement system, electronics and control, electrical system and graphic interface for device control and image formation. The DMT has an accuracy of ± 1C, at room temperature between 0C and 50C, having a useful reading area of 20x22 cm, producing images with 320x360 pixels, and capable of reading objects with temperatures between 0C and 300C.

7
  • Gabriel Lefundes Vieira
  • GAZE ESTIMATION VIA ATTENTION-AUGMENTED CONVOLUTIONAL NETWORKS

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • CARLOS HITOSHI MARIMOTO
  • EDUARDO FURTADO DE SIMAS FILHO
  • LUCIANO REBOUCAS DE OLIVEIRA
  • Data: Nov 25, 2020


  • Show Abstract
  • A estimativa de olhar (do inglˆes — gaze estimation) ´e altamente relevante para aplica¸c˜oes em v´arios campos, incluindo, mas n˜ao se limitando a, sistemas interativos, interfaces homem-computador e pesquisa comportamental. Como muitas outras tarefas de vis˜ao computacional, a estimativa do olhar se beneficiou muito com o avan¸co do aprendizado profundo (do inglˆes — deep learning) na ´ultima d´ecada. Recentemente, uma s´erie de data sets de larga escala para estimativa de olhar baseada em aparˆencia foram tornados p´ublicos, e redes neurais foram estabelecidas como a abordagem padr˜ao do estado-da-arte para essa tarefa. Atualmente, por´em, ainda h´a espa¸co para melhorias no que diz respeito `as arquiteturas de rede usadas para realizar a estimativa do olhar com base na aparˆencia. Um caminho promissor para melhorar a precis˜ao da estimativa do olhar ´e levar em considera¸c˜ao as informa¸c˜oes de pose da cabe¸ca que s˜ao implicitamente presentes em imagens faciais. Alguns trabalhos conseguem aproveitar essa informa¸c˜ao usando a imagem inteira do rosto como entrada para a rede neural. Uma desvantagem dessa estrat´egia ´e que as redes neurais convolucionais tradicionais n˜ao s˜ao capazes de formar rela¸c˜oes espaciais entre elementos distantes de uma imagem. Este ´e um fator significativo na estimativa da pose da cabe¸ca, dado que a mesma ´e determinada por uma combina¸c˜ao de diferentes caracter´ısticas de olhos, nariz, boca, etc. Tendo isso em mente, aqui propomos uma nova abordagem que usa camadas de convolu¸c˜ao melhoradas por auto-aten¸c˜ao para aumentar a qualidade das caracteristicas aprendidas pela rede, dando `a mesma a capacidade de formar rela¸c˜oes espaciais complexas de longo alcance. Nossa abordagem, quando aplicada a redes residuais mais rasas, pode ajud´a-las a superar arquiteturas profundas, aprendendo a identificar dependˆencias entre regi˜oes distantes em imagens de rosto inteiro, criando representa¸c˜oes mais sens´ıveis ao espa¸co a partir das imagens de rosto e olhos. Essa representa¸c˜ao ´e utilizada para estima¸c˜ao do olhar atrav´es de uma regress˜ao. Um efeito colateral interessante de nossa abordagem ´e tamb´em que ela ´e capaz de criar representa¸c˜oes intermedi´arias mais interpret´aveis visualmente, derivadas dos pesos usados pelas camadas de auto-aten¸c˜ao, possivelmente permitindo discuss˜oes interessantes sobre o processo de aprendizagem da rede. Denominamos nosso framework de estimativa de olhar como ARes-gaze. Ele explora nossa Atention-augmented ResNet (ARes-14) como backbones convolucionais gˆemeos para processamento das entradas. Em nossos experimentos, os resultados mostraram uma diminui¸c˜ao do erro angular m´edio em 2,38% quando comparados aos m´etodos mais modernos no data set MPIIFaceGaze e alcan¸caram o segundo lugar no data set EyeDiap. E importante notar que nosso framework proposto foi o ´unico a atingir alta precis˜ao ´ simultaneamente em ambos os conjuntos de dados entre os m´etodos avaliados.

8
  • VICTOR SANTOS CRUZ
  • Implementation of Models for the Propagation of Radio Waves over the Maritime Surface for the ns-3 Network Simulator

  • Advisor : FLAVIO MORAIS DE ASSIS SILVA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • FLAVIO MORAIS DE ASSIS SILVA
  • LEIZER SCHNITMAN
  • VITALY FELIX RODRIGUEZ ESQUERRE
  • Data: Dec 18, 2020


  • Show Abstract
  • This work describes the implementation of a tool for simulating wireless communication networks, considering the characteristics of radio wave propagation near the sea surface. The tool is an extension of the ns-3 Network Simulator and supports two propagation

    loss models: Two Ray Maritime Model, which models the reflection effects of electromag- netic waves on the sea surface; and Three Ray Maritime Model, which additionally models the effects of refraction of electromagnetic waves due to the existence of evaporation ducts in the troposphere. As the Three Ray Maritime Model has the height of the evaporation duct as a parameter, a model was also implemented to estimate that height based on climatic conditions. The propagation models implemented consider a line of sight between the transmitter and receiver antennas.

    With the described tool, we show how, in some situations, under different evaporation duct heights, the radio signal loss related to the increase in distance between transmitter and receiver is less than that predicted by some propagation loss models which do not consider the existence of these ducts. This reinforcement of the received signal caused by the existence of the evaporation duct can be considered positive, as it might extend the network coverage, or negative, in the sense that, as the signal travels longer distances, interference may occur between stations that operate at the same frequency. Hence the need to model these effects due to the current context of growing interest in wireless marine communications to support different types of applications, such as surveillance, security and ecological monitoring.

    The extension of ns-3 is of particular importance, as it is one of the most used simulators to design and evaluate communication networks.

Thesis
1
  • POMPÍLIO JOSÉ SILVA ARAÚJO JÚNIOR
  • Intelligent drones to investigate criminal scenes

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • ANDRE GUSTAVO SCOLARI CONCEICAO
  • DAVID MENOTTI GOMES
  • FLAVIO DE BARROS VIDAL
  • LUCIANO REBOUCAS DE OLIVEIRA
  • PAULO CESAR MACHADO DE ABREU FARIAS
  • Data: Feb 13, 2020


  • Show Abstract
  • A location associated with a committed crime must be preserved, even before criminal experts start collecting and analyzing evidences. Indeed, crime scenes should be recorded with minimal human interference. In order to help specialists to accomplish this task, we propose an intelligent system for investigation of a crime scene using a drone. Our system recognizes objects considered important evidence at the crime scene, defining the trajectories by which a drone performs detailed search. Existing methods are not dedicated to seeking evidence at a crime scene or are not specific to unmanned aircrafts. Our system is structured into three subsystems: (i) Aircraft auto-location, so-called Air-SSLAM, that estimates drone pose as well as provides coordinates to proportional-integral-derivative controllers for aircraft stabilization, (ii) controllers act in pairs in each direction to keep the aircraft on a calculated trajectory using the initial detected evidences, (iii) a new multi-perspective based detector analyzes multiple images of the same object in order to improve the reliability of object recognition. The goal is to make the drone fly through the paths defined by the objects recognized in the scene. Each subsystem was separately evaluated and so the complete system. At the end, Air-SSLAM presented a translational average error (TAE) of 0.10, 0.20, and 0.20 meters in the X, Y, and Z directions, respectively, and the average accommodation time of the controllers was between 10 and 20 secs. Our multi-perspective detection method increased 18.2% the detection rate of the baseline detector. In our experiments, we showed that the more perspectives, the higher the accuracy for localizing the evidences in the scene. The evaluation of the complete system was performed in a simulator, as well as in a real-world environment. The entire system, called Air-CSI, correctly identified all the objects in a controlled tested scenario, taking an average of 13.6 perspectives to identify an object. At the end of surveying the crime scene, Air-CSI produces a report containing a list of evidences, sketches, images and videos collected during the investigation

2
  • JOSE ALEJANDRO MORENO ALFONZO
  • CONTINUOUS SOLAR SIMULATOR WITH LARGE AREA FROM COMMERCIAL SPOTLIGHT AND METALLIC STEAM LAMPS

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • ANGELES LOPEZ AGÜERA
  • DENIS GILBERT FRANCIS DAVID
  • IURI MUNIZ PEPE
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • NELSON VEISSID
  • TIAGO FRANCA PAES
  • Data: May 18, 2020


  • Show Abstract
  • The Laboratory of Certification of Components of Systems of Photovoltaic Solar Energy (LABSOLAR) located in the Technological Park of Bahia aims to certify photovoltaic modules. Therefore, one of the equipment that it needs in its facilities is a steady-state solar simulator of large area used for continuous exposure tests in controlled environments. The Laboratory of Optical Properties (LAPO) of the Federal University of Bahia (UFBA) perceived a great opportunity to develop this equipment considering its high cost in the international market. Thus, a low-cost equipment was developed applying mechatronics techniques using commercial spotlights installed in a structural aluminum frame adapted in an automotive elevator. Metallic MSR lamps were used as a radiation source. This unprecedented lamp in this type of equipment allows to reproduce the AM1.5G reference spectrum and spectra characteristic from clear and cloudy sky present on deserts or temperate climates. The final result of this work was a Continuous Solar Simulator with BCA classification in relation to spectral correspondence, non-uniformity and temporal instability respectively, in accordance with the IEC 60904-9 standard. Another important development of this work was the creation of a single non-uniformity meter. It is capable to make radiation maps very fast enabling the calibration process faster and more dynamic from simple parameters configuration. Finally, it is noteworthy that the steady-state solar simulator still has potential for improvement to reach international class, and further increase and deepen the knowledge in this area.

3
  • SÉRGIO RICARDO XAVIER DA SILVA
  • Computational Efficiency Analysis for Solving the Inverse Kinematics Problem of Anthropomorphic Robots Using Gröbner's Theory of Bases.

     
  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • LEIZER SCHNITMAN
  • FERNANDO AUGUSTO DE NORONHA CASTRO PINTO
  • FERMIN DE LA CARIDAD GARCIA VELASCO
  • ALEXANDRE QUEIROZ BRACARENSE
  • FELIX MAS MILIAN
  • VITALINO CESCA FILHO
  • Data: Jul 13, 2020


  • Show Abstract
  • The Denavit-Hartenberg algorithm is a method used for decades to solve one of the classic problems in robotic manipulator kinematics, the inverse kinematics problem. When this method is used, there is a need for additional algorithms to solve the problem, such as Paul's method. Gröbner's Theory of Bases for solving inverse kinematics, as a supplementary method to the Denavit-Hartenberg algorithm, will be presented in this work. To favor a better understanding of the reader with each method, the Stäubli TS20 robot manipulators, a SCARA type robot, and the Unimation PUMA 560, an anthropomorphic manipulator with six rotating joints, will be used as case studies applying the method of Paul and the method proposed in this work, where computational efficiency data will be used for comparison. The main objective of this work is to analyze the computational efficiency in solving the problem of inverse kinematics of anthropomorphic robot manipulators using both methods. With each approach, the inverse kinematics problem for the two serial robots will be solved. By comparing each method, this work will demonstrate that the method based on Gröbner's Theory of Bases is computationally more efficient for solving the inverse kinematic problem of anthropomorphic robots.

4
  • JOSÉ CARLOS DA SILVA
  • Distributed Algorithm for TSCH Transmission Scheduling under SINR

  • Advisor : FLAVIO MORAIS DE ASSIS SILVA
  • COMMITTEE MEMBERS :
  • ALIRIO SANTOS DE SA
  • FLAVIO MORAIS DE ASSIS SILVA
  • HERMAN AUGUSTO LEPIKSON
  • KARCIUS DAY ROSARIO ASSIS
  • MARCELA SILVA NOVO
  • Data: Sep 1, 2020


  • Show Abstract
  • Industrial environments are typically characterized by high levels of interference. Therefore, the standards for industrial wireless sensor networks (WirelessHART, ISA 100.11a and IEEE 802.15.4e) have defined a mode of operation based on time division and multichannel, in which time intervals and channel pairs are assigned to links representing a communication between two nodes. In IEEE 802.15.4e, this mode of operation is called Time Slotted Channel Hopping (TSCH). In this work, a distributed algorithm to define such an assignment for a given network is described. The algorithm is efficient, scalable and was developed for the Signal-to-Interference-plus-Noise Ratio (SINR) model, currently considered the most suitable for analyzing algorithms for wireless networks when interference is carried out. in consideration. In particular, the algorithm provides deterministic communication on the network. Previous approaches to this problem are mainly centralized, based on a simple (or none) interference model or do not consider multiple physical channels. In this work, we describe the algorithm and present results of the simulation, where we evaluate the number of rounds necessary to calculate the schedules and the size of the schedules produced. The described algorithm applies to the Internet of Things, characterized by the high scale and presence of interference.

2019
Dissertations
1
  • VINÍCIUS LUIS DE CARVALHO SILVA
  • “Low cost container tracking and tracing system”

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • ALIRIO SANTOS DE SA
  • HERMAN AUGUSTO LEPIKSON
  • ROBERTO LUIZ SOUZA MONTEIRO
  • Data: Mar 7, 2019


  • Show Abstract
  • The service provided by the Brazilian ports is among the most expensive in the world, a fact attributed mainly to their technological gap, with emphasis on infrastructure, logistics and automation, which are interdependent factors and have a strong impact on operating costs and system efficiency.
    Among the most relevant issues is the tracking of containers along their entire route, from ship to recipient and back to ship. Therefore, it is a current and widely researched theme in view of the new technologies that have been made viable, and which have peculiarities inherent to each country. In the case of Brazil, the characteristics of the most widely used modal systems, regionalities, tax and fiscal aspects and systemic deficiencies should be considered.
    This work emphasizes the challenge of obtaining a low cost system capable of locating containers inside and outside the port. As a result of the implementation of this solution it is mainly expected to reduce operating costs arising from the presence of checkers in the yards, eliminate the loss of cargo and search time caused by human error, allow the location and / or online tracking of all containers. from the Web. The solution has innovative features backed by patent applications and with great potential to become a marketable product.
    The embedded system developed has a microcontroller, an internal mapping identification and location system, as well as a georeferenced tracking system. Basically, the identification system handles the location of containers within the port yard.

    Through algorithms developed based on the technology adopted and supported by a database, the system is able to determine the position of all containers in the yard, whether they are on the floor or stacked over other containers. The georeferenced system is responsible for tracking containers when they are outside the port environment, being able to provide the route and location of each asset at programmable intervals.

    Validation and testing of system dynamics and behavior in typical yard movements was performed on a container model built using structural material similar to the actual one. These tests allowed simulating and proving the efficiency of the system against the established objectives. To validate the concepts of mobility and the ability to communicate in a real environment, the prototypes were tested in a container carrier container yard and proved functional and adaptable to meet specificities.

2
  • JOSE EMILIO QUESADO DE SOUZA
  • Self-Powered Wireless Vibration Analyzer

  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • FABIANO FRAGOSO COSTA
  • IURI MUNIZ PEPE
  • Data: Apr 5, 2019


  • Show Abstract
  • This work presents the study and design of vibration analyzer self-powered by energy harvesting, using piezoelectric and magnetic components to convert mechanical energy into electric energy. A prototype vibration analysis instrument was developed to monitor the operating state of machines and motors. This system is powered by a Lithium battery which by its own is recharged by the generator, providing the configuration of self-sufficient to the system. The hybrid structure proposed in this work analyzes and demonstrates the gains and obtained from the miscegenation of two generator models. The results obtained from simulations and tests in the experimental platform show an effective solution for power generation for low energy consumption devices and instruments.

3
  • MATHEUS OLIVEIRA DE BRITO
  • Thermosolar didactic plant for modeling, identification, simulation and control tests

  • Advisor : MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • COMMITTEE MEMBERS :
  • ACBAL RUCAS ANDRADE ACHY
  • BERNARDO ORDONEZ
  • IURI MUNIZ PEPE
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • Data: May 10, 2019


  • Show Abstract
  • This work proposes a didactic thermosolar plant for model studies, simulations and process control. The thermosolar plant uses solar energy to perform the heating of a fluid generating heat, an input that is widely used in industry. In addition to the physical structure of the plant, some instruments were developed for the sensing of important physical quantities, such as solar irradiance and the state of the control valve. One of the objectives of this work is to offer a study environment that approximates the theoretical foundations of teaching to the industrial reality, a primordial philosophy for the area of education in engineering. The equipment allows analyzes and applications in modeling, simulation and control through Matlab / Simulink and Labview softwares. A case study is presented in order to demonstrate the functionalities of the proposed system, being possible the study and application of advanced control.

4
  • SAULO MASCARENHAS FRÓES
  • TECHNIQUE FOR OBTAINING ANTENNA RADIATION DIAGRAMS IN ECOLOGICAL ENVIRONMENTS
  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • EDUARDO FURTADO DE SIMAS FILHO
  • MARCELA SILVA NOVO
  • Data: Jun 7, 2019


  • Show Abstract

  • Anechoic chambers are indicated for the determination of antenna radiation diagrams, among other quantities. This is because cameras of this type are produced with materials that absorb electromagnetic waves, reducing the occurrence of reflections. However, anechoic chambers are often too costly for small businesses or university centers to acquire. In the state of Bahia, for example, there is only one semi-anechoic chamber and none completely anechoic. In order to overcome this difficulty, several techniques are currently being developed with the purpose of suppressing the effect of echoes in measurements performed in echo environments. This has proven to be possible through the use of digital signal processing techniques based on classical concepts such as deconvolution, impulse response and filtering. In this work, a technique for obtaining the radiation diagram in non-anechoic environments was studied. Briefly, the method consists of making measurements taken at different initial positions of the transmitting and receiving antennas and, through a similarity identification algorithm, reconstructing the real radiation diagram. The reconstructed diagram was then evaluated from the comparison with the radiation diagram obtained in an anechoic chamber. The obtained results indicated that the proposed technique is promising for the reconstruction of antenna radiation measured in echo environments. A better functioning of the technique was observed especially when peaks / attenuations due to reflections occurred in only one specific position.

5
  • ÉRICO AUGUSTO NUNES PINTO
  • Fuzzy Logic Based Financial Operations Recommendation System.

  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • LEIZER SCHNITMAN
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • MARCIO FONTANA
  • Data: Jun 17, 2019


  • Show Abstract
  • Making predictions and providing buy and sell recommendations in the stock market are usually considered difficult tasks, given the complex behavior of financial asset price movement, which is regarded as dynamic, nonlinear, and stochastic. Just as in the fields of knowledge where artificial intelligence (AI) techniques are applied to obtain accurate and faster information, companies that constantly provide trading recommendations seek to gain advantages using AI systems and mathematical modeling, reducing analysis time. and increasing the accuracy of recommendations. This paper presents the application of systems based on fuzzy logic to predict the price behavior of a set of shares of companies listed on the Bovespa and to recommend a strategy of buying and selling shares on a daily basis, based on indicators and price estimates. . A first recommendation system relies on classical rules of technical analysis to predict stock price movement, relying solely on the combination of some indicators, such as: Relative Strength Index (RSI), Stochastic and Williams. This strategy, although commonly exploited by the market, is unable to escape the stochastic influence of price series, ie it does not provide, for example, long sequences of hits. To this end, a second recommendation system was proposed, which differs from the previous one by also considering price forecasting information based on the stochastic model of stock behavior known as the Brownian Geometric Motion (MBG) in addition to the OBV indicator. On Balance Volume). The results presented by the systems had their performances compared from the number of recommendations and hits. With the first system it was shown that not all assets can be operated from a similar set of indicators, affecting the financial results. The second, which was aided by the price forecast proposal, achieved better performance and consistency in the recommendations.


6
  • JOSÉ MARCELO DE ASSIS SANTOS
  • PHOTOVOLTAIC DATA ACQUISITION SYSTEM FOR CHARACTERIZATION OF LOCAL INSOLATION FOR SUPPORT SERVICE FOR MICRO AND SMALL GENERATORS

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • EDSON PEREIRA MARQUES FILHO
  • ITA TEODORO DA SILVA
  • IURI MUNIZ PEPE
  • Data: Jun 28, 2019


  • Show Abstract
  • The generation of electric energy from solar energy is an alternative to the traditional energy matrix and, increasingly, its participation in the energy generation market is increasing. Solar irradiation depends on several factors, such as: locality, season, atmospheric composition, cloud cover and surface shape. As the intensity of the solar radiation is variable, a survey of its values is necessary to guarantee a better use of the generation system throughout the year. In this work, a photovoltaic data acquisition and sensing system was implemented to characterize the local insolation, based on three solar cell technologies, namely: monocrystalline silicon, polycrystalline silicon and thin film. During the calibration and validation tests, the saturation of the silicon cell signals was observed when the external resistive load was greater than 30 ohm. This saturation can be avoided by the use of an acrylic bulkhead, with two hole matrices, which served as a collimator and attenuator (attenuation ratio of -12.0 ± 0.5 dB). The developed system was able to determine the normalized efficiency of the solar cells during the day, in different seasons of the year. Thus in the winter the cell that has the highest normalized efficiency was CIGS, whereas in the spring this domain falls, remaining at the beginning and at the end of the day. In the summer the silicon cells show higher normalized efficiency when compared to the CIGS cell.

7
  • GUSTAVO DE ALMEIDA NEVES
  • ROTATED MULTI-OBJECT DETECTION  FROM FORWARD-LOOKING SONAR IMAGES

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • EDUARDO FURTADO DE SIMAS FILHO
  • LUCIANO REBOUCAS DE OLIVEIRA
  • PAULO CESAR MACHADO DE ABREU FARIAS
  • Data: Nov 13, 2019


  • Show Abstract
  • The underwater world is a hazardous place to people, being even unreachable in some
    places. It is common to employ manned or unmanned underwater vehicles, when human
    activities have to be performed underwater. Particularly, oil and gas companies have
    used remotely operated vehicles (ROVs) to inspect and maintain submerged structures
    of subsea facilities. Because of the complexity and the high cost of ROV operations, some
    researches have addressed autonomous underwater vehicles (AUVs) to perform inspection
    tasks under water. AUVs are typically equipped with perception sensors, such as optical
    cameras and sonars that ultimately provide visual and acoustic information of underwater
    scenarios. With the goal of comprehending the surrounding environment, object detection
    over perception sensor data is a crucial task. Indeed, detected objects can be used for
    many applications of the AUV system, such as to locate obstacles, to provide landmarks
    for the navigation, to move the vehicle with respect to a detected target object and to plan
    AUV trajectories. Although optical cameras are still important sensors for AUVs, their
    sensing capability is limited underwater, being only able to work at very short ranges,
    and in low-turbidity water conditions. In contrast, sonars can cover larger operative
    ranges through the water and work in turbid water conditions. However sonars provide
    noisy data with lower resolution and more dicult interpretation, thus making object
    recognition in sonar images an arduous task. Having all this in mind, our work propose
    a novel multi-object detection framework that outputs object position and rotation from
    sonar images. Two convolutional neural network based architectures are proposed to
    detect and estimate rotated bounding boxes: An end-to-end system, called RBoxNet,
    and a pipeline comprised of two networks, called YOLOv2+RBoxDNet. Both proposed
    approaches are structured from one of three representations of rotated bounding boxes
    regressed deep inside. To the best of our knowledge, there is no other work in the
    literature that estimates rotated bounding boxes in sonar images. Experimental analyses
    were performed by comparing several con gurations of our proposed methods (by varying
    backbone, regression representation and architecture) with other state-of-the-art methods
    over real sonar images. Results showed that RBoxNet presented the best tradeo between
    accuracy and speed, reaching an averaged mAP@[.5,.95] of 90:3% at 8:58 frames per
    seconds (FPS), while YOLOv2+RBoxDNet was the fastest solution running at 16:19
    FPS, but with a lower averaged mAP@[.5,.95] of 77:5%. Both proposed methods were
    robust to variations of additive Gaussian noise, detecting objects even when the noise
    level is up to 0:10.

8
  • IGOR MENDES LIMA PATARO
  • ADVANCED SIMULATION OF D-RTO ASSOCIATED WITH PREDICTIVE CONTROL STRATEGIES FOR ETHANOL DISTILLATION COLUMNS
  • Advisor : MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • COMMITTEE MEMBERS :
  • HERMAN AUGUSTO LEPIKSON
  • JULIO ELIAS NORMEY RICO
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • RODOLFO CÉSAR COSTA FLESCH
  • Data: Nov 19, 2019


  • Show Abstract
  • Alcoholic distillation, one of the main productive stages of the sugar and alcohol industry, still shows timid results in terms of automatic control and optimization. However, advanced control approaches give us good prospects for improving safety, efficiency and productivity in this type of process. In particular, predictive control techniques, widely known as MPC (Model Predictive Control) allow the operation of the distillation columns considering the complexity of the system, such as multiple inputs and outputs and numerous disturbances that can compromise the quality of the products. In addition, strategies based on time compensators, such as the filtered Smith Predictor (FSP), can incorporate formulations that allow to increase the robustness of the closed loop control system. From this perspective, this work presents the application of an advanced control structure in two layers. The first layer consists of implementing a predictive control system. In particular, the infinite horizon (IHMPC), MIMO FSP and DTCGPC were designed, capable of maintaining the alcoholic distillation process under the conditions defined as a reference. For the second layer, a dynamic optimizer in real time was developed, capable of calculating the best operation points of the process using a reliable model, considering economic and productivity conditions. For that, a computational platform was also developed that allows the advanced simulation of the system as well as its dynamic behavior in a Software-in-the-Loop environment as a way to guarantee the fidelity of the results and propose the application of these strategies in a real scenario. OLE (Object Linking and Embedding) Automation integrates Matlab and Aspen Hysys software to simulate practical OPC (Open Platform Communications) scenarios commonly found in the industry. Controllers are evaluated, in simulation scenarios, from control performance indexes (ITAE, ITSE, SSC) and the computational performance of each strategy, as a quantitative metric for comparing the proposed structures. Furthermore, the economic performance of the optimization layer is compared with the classic PID control strategy still applied in the sugar and alcohol industry. This study showed that the dynamic optimization associated with predictive controllers increased the production of the distillation column, showing itself to be more robust and stable compared to the approaches commonly used in the current scenario of ethanol distilleries. In view of the particular benefits of each strategy, this work aims to propose different control solutions for different scenarios of the sugar and alcohol industry, in order to maintain a more efficient, economical and clean production. In addition, it is intended to evolve the practical application of advanced control strategies that take into account the stability of the system, the efficiency of production and the robustness in closed loop.

9
  • RAFAEL SILVA DE LIMA
  • Development of Combined Beta-CUSUM Binomial control charts for monitoring nonconforming products

  • Advisor : CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • COMMITTEE MEMBERS :
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • ANGELO MARCIO OLIVEIRA SANT ANNA
  • DANILO MARCONDES FILHO
  • MAURICIO SANTANA LORDELO
  • Data: Nov 29, 2019


  • Show Abstract
  • Statistical process control charts are tools widely used to monitor the quality of products, processes and services. Proposals for Shewhart in 1924 are traditionally applied because of their ease of implementation and analysis. Over the years, various control codes are allowed in the Shewhart type, with increased performance or performance due to process automation and high quality product use. However, these letters have a disadvantage of not detecting small changes within productive processes, where the use of cumulative sum letters (CUSUM) proposed by Page in 1954 is more appropriate. When a magnitude of change within a process is not known, one of the solutions is an application of combined cards as characteristics of Shewhart cards with CUSUM cards. The objective of this work is the development of a combined control chart as a control chart features, with beta distribution and accumulated total attributes chart, based on binomial distribution. Binomial Beta-CUSUM combined chart development procedures and their application to discrete and continuous data are demonstrated. The results show that a combined chart performs similarly to the Shewhart-CUSUM Binomial chart when applied to discrete data and performs better when applied to continuous data. Thus, a proposed Beta-CUSUM Binomial letter is valid and is a new combined letter alternative for monitoring nonconforming items.

10
  • IGOR CORDEIRO DOS SANTOS
  • DIAGNOSIS OF KNOWLEDGE MANAGEMENT IN CIVIL CONSTRUCTION COMPANIES USING THE FUZZY-AHP METHOD
  • Advisor : CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • COMMITTEE MEMBERS :
  • ANGELO MARCIO OLIVEIRA SANT ANNA
  • AVA SANTANA BARBOSA
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • DAVI NOBURO NAKANO
  • Data: Dec 13, 2019


  • Show Abstract
  • Diagnosis of Knowledge Management based on the measurement of performance indicators in Brazilian civil construction companies in the building sector, whose main activities are: execution of residential works and industrial and commercial buildings. Use of knowledge management using performance indicators in the field of civil construction, aiming to study its application effectiveness and convergence of the identified results. The available literature is focused on the conceptual field, without effective proof of application and validation in practice. A self-administered questionnaire for data collection was elaborated, with subsequent application of the Diffuse Analytical Hierarchical Method (Fuzzy-AHP) to choose and make decisions about the best Knowledge Management model for the Brazilian civil construction sector. The use of Fuzzy-AHP to diagnose the importance and performance of Knowledge Management for Brazilian Civil Construction Organizations in the Buildings sector ratified the need for a structured approach so that organizations can remain in constant learning, productive and competitive. Performance gaps and opportunities for improvement in the field of knowledge were identified as knowledge management is centered on controls that do not necessarily provide opportunities for improvement for organizations, being used only as a source of data and information to support research. reaction to the failures that occurred, without visualization by all hierarchies, mainly the tactical and operational levels. It is important to emphasize the implications of this research related mainly to the nature of qualitative work. As it involves subjective elements of analysis and considerations, the present situation and feeling of the participants reflectedand considerations, the situation and present feeling of the participants reflected considerably in the contributory actions of this research. Similarly, there are the limitations of Knowledge Management itself, as it includes intangible assets, which are difficult to measure, especially if related to tacit knowledge. Despite a vast body of literature on Knowledge Management, the article demonstrates these factors within a Brazilian context. An essential point is that the study is based on feedback from construction professionals and managers, who carry out their analyzes and conclusions from practical points of view, without relevant theoretical knowledge of the relationship between the process variables. The Diffuse Analytical Hierarchical Method applied to the theme of Knowledge Management through Performance Indicators in Civil Construction addresses the degrees of imprecision arising from difficulties and ambiguities of human perception.

     

     

11
  • KLEBER DE LIMA SANTANA FILHO
  • Classification of Hand and Fist Gestures Through Muscle Synergies.
  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • ANGELO AMANCIO DUARTE
  • LEIZER SCHNITMAN
  • TEODIANO FREIRE BASTOS FILHO
  • Data: Dec 19, 2019


  • Show Abstract
  • This paper proposes a new approach for the activation of pattern recognition myoelectric devices, using a convolutional neural network model, which receives input extracted characteristics based on the concept of muscle synergies. This concept is based on the assumption that the central nervous system controls movements by combining muscle groups, rather than directly controlling each degree of freedom, thereby reducing the number of parameters that need to be controlled. Non-Negative Matrix Factorization (NMF) algorithms are used to extract synergies in the form of matrix factorization activation signals, allowing these signals to be used in the control of myoelectric devices. The new approach utilizes the estimation of neural control activations, notably force functions, in conjunction with a deep learning pattern recognition model to enable improved accuracy rates in the task of recognizing sets of hand and wrist gestures. The proposed technique was evaluated by 3 different tests, for which signals extracted from two public databases (NINAPRO Project and CAPGMYO) were used.

Thesis
1
  • GILDEBERTO DE SOUZA CARDOSO
  • Transverse Feedback Linearization Applied to RRT*

  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • CRISTIANO HORA DE OLIVEIRA FONTES
  • LEIZER SCHNITMAN
  • MARCIO ANDRE FERNANDES MARTINS
  • THIAGO PEREIRA DAS CHAGAS
  • TIAGO TRINDADE RIBEIRO
  • Data: Jun 10, 2019


  • Show Abstract
  • The thesis deals with the analysis of the feedback transverse linearization as a control for a unicycle robot's navigation. The path to be followed by a robot will be given through a set of curves whose distance is Euclidean. Feedback transverse linearization makes this path attractive and time-invariant, it means that, if the robot is initialized on the path with an appropriate orientation, it will remain on the path for all the time. The limitation of the technique is analyzed when the angle between the segments of lines that compose the path is obtuse, in this case, the robot follows an opposite path to the desired. There was no evidence in the literature of limitation of transverse feedback linearization when the angles are obtuse. It is mathematically demonstrated the existence of a set of controller gain values that guarantee that the robot will follow the desired path, if the angle formed between the straight segments of the path is acute. Dynamic Transverse Feedback Linearization is proposed as a solution to this limitation. For the purpose of exemplifying the proposed control, the transverse feedback linearization with the rapidly exploring random trees star is integrated, modifying the path planner in order to meet the limitation of the transverse feedback linearization. Here, such linearization is compared with dynamic transverse feedback linearization. Transverse feedback linearization is applied to the Kobuki robotic platform in order to experimentally show the robot convergence in a direction opposite to the desired one.

2
  • DION BARBOSA DOS SANTOS RIBEIRO
  • Project Neutrinos Angra: the final detector ,redesigne , assembly and commissioning.
  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • IURI MUNIZ PEPE
  • TIAGO FRANCA PAES
  • MARCUS VINICIUS AMERICANO DA COSTA FILHO
  • ANTONIO FERREIRA DA SILVA
  • JOÃO CARLOS COSTA DOS ANJOS
  • DENIS GILBERT FRANCIS DAVID
  • Data: Jul 5, 2019


  • Show Abstract
  • The Neutrinos Angra project aims to monitor the thermal power and evolution of fissile fuel of the Angra II nuclear power plant, located at Almirante Álvaro Alberto Nuclear Power Station, in Angra dos Reis, to corroborate the development of nuclear safeguards and the detection physics of nuclear fuels. neutrinos at surface level. For this purpose, a neutrino detector based on Cherenkov radiation detection in 0.2% by mass gadolinium doped ultra pure water was installed adjacent to the reactor building of this plant. The project is a collaboration started in 2006 that soon became a 100% Brazilian project. This condition promoted unparalleled development of local content and personnel, but also imposed serious restrictions and delays on project implementation. The detector developed is a concentric tank monolith with a 32 photomultiplier polypropylene target tank and 1.3 cubic meters of gadolinium-doped water. Surrounding it is a two-volume polypropylene shielding with 1.65 m3 and 3 m3, respectively, and 4 photomultipliers for barring muons and neutrons. Above this set is an additional veto tank with 1.45 m3 of water and 4 sensors. This detector is connected to a data acquisition system composed of signal conditioning, discrimination, discretization, selection and storage modules. This paper describes the neutrino detector assembly at the Brazilian Center for Physical Research, where it was tested; the subsequent disassembly of the same, its transportation and final assembly in the laboratory container of the project at CNAAA; and finally, the commissioning of this detector.


3
  • AYDIN JADIDI
  •  SHORT-TERM FORECASTING OF THE GLOBAL HORIZONTAL IRRADIANCE AND ELECTRICAL POWER DEMAND USING MACHINE LEARNING TECHNIQUES

  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • MARCIO ANDRE FERNANDES MARTINS
  • FABIANO FRAGOSO COSTA
  • ANGELO AMANCIO DUARTE
  • GERMANO CRISPIM VASCONCELOS
  • Data: Sep 6, 2019


  • Show Abstract
  • The use of photovoltaics is still considered to be challenging because of certain reliability issues and high dependence on the global horizontal irradiance (GHI). GHI forecasting has a wide application from grid safety to supply-demand balance and economic load dispatching. On the other hand, load forecasting is important for smart grids and the electricity market in terms of the meeting the demand and distribution of electrical energy. The current research develops a methodology for more precise forecasting results. Two different approaches are developed and applied for GHI forecasting and electric load forecasting. Given a data set, a multi-layer perceptron neural network (MLPNN) is a strong tool for solving the forecasting problems. Furthermore, noise detection and feature selection in a data set with numerous variables are of crucial importance to obtain the desired results. This work employs density-based spatial clustering of applications with noise (DBSCAN) and non-dominated sorting genetic algorithm II (NSGA II) algorithms for noise detection and feature selection, respectively. Tuning the neural network is another important issue that includes choosing the hidden layer size and activation functions between the layers of the network. Previous studies have utilized a combination of different parameters based on trial and error, which seems to be inefficient in terms of accurate selection of the desired features and also tuning of the neural network. In this research, two different methods namely, particle swarm optimization (PSO) algorithm and genetic algorithm (GA) are utilized in order to tune the MLPNN, and the results of one-hour ahead forecasting of the GHI are subsequently compared. The methodology is validated using the hourly data for Elizabeth City located in North Carolina, USA, and the results demonstrated a better performance of GA in comparison with PSO. For electric power demand forecasting, this research proposes a hybrid algorithm for improving the forecasting accuracy where a non-dominated sorting genetic algorithm II (NSGA II) is employed for selecting the input vector, where its fitness function is a multi-layer perceptron neural network (MLPNN). Thus, the output of the NSGA II is the output of the best-trained MLPNN which has the best combination of inputs. The result of NSGA II is fed to the Adaptive Neuro-Fuzzy Inference System (ANFIS) as its input and the results demonstrate an improved forecasting accuracy of the MLPNN-ANFIS compared to the MLPNN and ANFIS models. In addition, genetic algorithm (GA), particle swarm optimization (PSO), ant colony optimization (ACO), differential evolution (DE), and imperialistic competitive algorithm (ICA) are used for optimized design of the ANFIS. Electricity demand data for Bonneville, Oregon are used to test the model and among the different tested models, NSGA II-ANFIS-GA provides better accuracy.

    The GA-tuned MLPNN reported a normalized root mean square error (nRMSE) of 0.0458 and a normalized mean absolute error (nMAE) of 0.0238 for hourly GHI forecasting and obtained values of error indicators for one-hour-ahead demand forecasting are 107.2644, 1.5063, 65.4250, 1.0570, and 0.9940 for RMSE, RMSE%, MAE, MAPE, and R, respectively.

4
  • ANDRE PIMENTEL MOREIRA
  • Double-Acting Submerged Hydraulic Linear Pump: Process and Device

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • ARMANDO SA RIBEIRO JUNIOR
  • HERMAN AUGUSTO LEPIKSON
  • LEIZER SCHNITMAN
  • MANUEL DE ALMEIDA BARRETO FILHO
  • VALTER ESTEVÃO BEAL
  • Data: Sep 9, 2019


  • Show Abstract
  • The present work describes the process and artificial lifting apparatus for a doubleacting mechanical pump using a hydraulic system designed to operate partially or completely submerged, and it is suitable for oil production at small, medium and large depths, denominated Double-Acting Submerged Hydraulic Linear Pump (BLS). The proposed device can be used in wells with different configurations (vertical or directional), for lifting fluids with API densities below 22◦ (heavy oil) to densities higher than 31◦ (light oil). Furthermore, it is a viable alternative for extracting water from the underground aquifers in the Northeast regions of Brazil. Given its unprecedented conception, this new concept and pumping system was the object of a recent patent deposited at the National Institute of Intellectual Property (BR 10 2015 019070 0). A prototype of the pumping device was developed to prove its operation. The speed variation tests of the hydraulic cylinders of the prototype compared to the computational simulation, showed only small distortions with an error of between 7.79% and 10.5% for rotations of the submersible electric motor running at between 1800 and 3600 rpm. The pumping test results of the cycle time of the cylinders and the production per cycle were compatible with those calculated and simulated in the Automation StudioTM software. The maximum error obtained was 8.67% between the system running on an experimental test bench and the simulated results. Considering the drive power/geometric lifting height ratio (kW/m), the nominal drive power of the BLS device presented an advantage in relation to the other lifting methods analyzed in this work. However, compared to the centrifugal pump used in the Guarani aquifer presented in this work, the BLS presented higher energy consumption for the drive power in relation to the volumetric flow (kW/m3/d). The comparison, although simplified, demonstrates that the BLS can be characterized as a low flow pump, but that it may soon be an option for production in deep reservoirs. Although the prototype has not yet been tested in a real operating environment, the results of the laboratory tests have been promising. Moreover, since this new pumping apparatus is inserted directly into the production zone, the problems such as those related to the sucker rod column are eliminated. As the greater part of the equipment of this proposed pumping system is in the well, the installation and maintenance tend to present low complexity. Although the work has been evaluated through laboratory tests and computational simulations, there is still potential to evolve its technological side further, giving rise to future work.

5
  • RÔMULO GUEDES CERQUEIRA
  • A multi-device sonar simulator for real-time underwater applications.

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • ANTONIO LOPES APOLINARIO JUNIOR
  • KARL PHILIPS APAZA AGUERO
  • LUCIANO REBOUCAS DE OLIVEIRA
  • Paulo Lilles Jorge Drews Junior
  • Silvia Silva da Costa Botelho
  • Data: Nov 25, 2019


  • Show Abstract
  • Mainly when applied in the underwater environment, sonar simulation requires modelling complex acoustic physics and simultaneously rendering time-efficient data. Simulation of sonar operation allows evaluating algorithms and control systems without going to the real underwater environment; that reduces the costs and risks of in-field experiments. Existing methods focus on a basic implementation of one sonar device type with high computational cost, where most of the sound properties are disregarded. Towards a high fidelity virtualization with real time constraints, our proposed system is able to reproduce the operation of two main types of imaging sonars: mechanical scanning imaging sonar and forward-looking sonar. The underwater simulated scene is performed based on three frameworks: (i) Gazebo handles with hydrostatic and hydrodynamic forces, (ii) OpenSceneGraph renders the ocean visual effects, and (iii) ROCK framework manages the sonar in the virtual underwater scenario and exports simulation resources. The underwater simulated scene is then processed by a hybrid rendering pipeline on GPU: Rasterization computes the primary reflections between the sonar and observable surfaces based on deferred shading, while only the reflective areas are ray-traced. Also, the parallel ray-box routines on GPU also accelerated the intersection tests on ray-tracing algorithm. This approach launches few rays when compared to a full ray-tracing, achieving a significant performance gain without quality loss in the final image. Resulting reflections are then characterized as two sonar parameters: Echo intensity and pulse distance, being all calculated over insonified objects in the 3D rendered scene. Sonar-intrinsic parameters, such as speckle noise, transmission loss, reverberation and material properties of observable objects are also considered as part of the final acoustic image. Our evaluation demonstrated that the proposed system is able to operate close to real-world devices in terms of computation time. Also, our method demonstrated the effectiveness to render complex scenes with high quality when compared with real-world sonar images of similar scenes.

6
  • MARIANE DOURADO CORREIA
  • OPEN PLATFORM FOR INTEGRATION OF SERVICES IN DISTRIBUTED MANUFACTURING PROCESSES

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • EDUARDO MANUEL DE FREITAS JORGE
  • HERMAN AUGUSTO LEPIKSON
  • LEIZER SCHNITMAN
  • MANOEL GOMES DE MENDONCA NETO
  • SERGIO GORENDER
  • Data: Dec 9, 2019


  • Show Abstract
  • With the growing digital transformation that is a relevant part of the new industrial revolution that has already begun, companies need to restructure to adapt to new technologies and the possible changes that signal a moment of transition from a classic and centralized hierarchical model of management and control of companies. information for a new structure that enables the required agility, flexibility and interoperability characteristics of your systems. To the extent that data enable remote and intelligent decision-making, decentralization of decision making, configurability in the production line and service-oriented applications are also important, particularities imposed by Industry 4.0 (I4). Given this scenario, it is crucial to create conditions for this inevitable transition from the classic industrial model of the automation pyramid to a model that projects itself in the near future. These new models should allow legacy and increasingly distributed devices to coexist in an environment compatible with new I4 technologies and molds. A relevant issue to address is the interoperability between heterogeneous shop floor systems, especially when it comes to distributed systems. This research aims to develop an open platform for integration - PAI, which is based on the service-oriented architectural model (SOA), with the objective of enabling interoperability between legacy devices along the lines of Industry 4.0. From an analysis of the best solutions to address the interoperability issue of legacy shop floor systems, along with I4 technology trends, an effective solution based on tools already available has been developed. To validate the proposed platform, three experiments were performed simulating real plants with a focus on process control, where a system capable of allowing service oriented operations, in a modular and scalable manner, aiming at interconnectivity, interoperability and transparency was observed.

2018
Dissertations
1
  • ODILON SANTANA LUIZ DE ABREU
  • Predictive Control with Stability Assurance Applied to Unstable Systems and Integrators

  • Advisor : MARCIO ANDRE FERNANDES MARTINS
  • COMMITTEE MEMBERS :
  • CRISTIANO HORA DE OLIVEIRA FONTES
  • MARCIO ANDRE FERNANDES MARTINS
  • THIAGO PEREIRA DAS CHAGAS
  • Data: Mar 23, 2018


  • Show Abstract
  • This work presents a predictive control strategy with stability assurance for systems composed of unstable and integrating modes. Such dynamic characteristics make it difficult to control the system, especially when the controller synthesis seeks to guarantee the stability of the system in closed loop. Here, a permanent error-free control law based on a single optimization problem is proposed, and closed-loop stability is achieved by adopting an infinite prediction horizon, which together with the imposition of a terminal constraint set associated with the system of unstable and integrating states, guarantees their viability. The results obtained from the simulated scenarios in two systems, CSTR (Reactor Continuous Tank Reactor) and rotational inverted pendulum, point to an efficient solution to systematically improve the control mesh.

2
  • TIAGO DE OLIVEIRA SILVA
  • A Service-Oriented Architecture for Supporting Integrated and Distributed Industrial Automation

  • Advisor : HERMAN AUGUSTO LEPIKSON
  • COMMITTEE MEMBERS :
  • ANA PAULA MAIA TANAJURA
  • ANTONIO CEZAR DE CASTRO LIMA
  • HERMAN AUGUSTO LEPIKSON
  • Data: Mar 26, 2018


  • Show Abstract
  • The industry is experiencing a new cycle, a new era of the industrial revolution. For companies to remain competitive on the market and adapt to new technological trends, a reformulation is necessary in their methods and processes, which tend to become increasingly distributed and complex. The purpose of this work is to use a service-oriented architecture to integrate applications on the shop floor in a modular and scalable way. In this approach, how information will travel across different industries and across the production cycle, as well as its availability where necessary across the enterprise, makes plant management more accessible from anywhere and in a standardized way. This work presents the development of a mediator that integrates an advanced controller into a computational tool via the Web system. The validation of its operation was done in an experimental unit of processes to control Tank Level. The tests were performed through experimental methods that allowed the application of predictive control in a distributed service oriented architecture. The results obtained showed that it is possible to apply local control through a service oriented approach.

3
  • LAURA XIMENA CHAPARRO GUAYARA
  • Configuring Multiple RGB-D Cameras for Motion Capture of Hemiparetic Patients

  • Advisor : LUCIANO REBOUCAS DE OLIVEIRA
  • COMMITTEE MEMBERS :
  • ALEXANDRE DA COSTA E SILVA FRANCO
  • LUCIANO REBOUCAS DE OLIVEIRA
  • VINICIUS MOREIRA MELLO
  • Data: Jun 29, 2018


  • Show Abstract
  • Classical mechanics, the oldest of the physical sciences, has been since its inception the tool used by humans to study its relationship with the environment in which it operates. Galileo, and then Newton, laid the groundwork for this to be done scientifically. Two procedures are used to study human movement: quantitative and qualitative analysis. Quantitative analysis describes the movements of the body or its parts in numerical terms, and qualitative analysis seeks to describe a movement in non-numerical terms. Motion analysis of the human body studies the objective variation of position within the space in which it develops and over a certain period of time. Over time, motion analysis began to be used as an evaluation of the evolution of physical therapy treatments. To analyze motion, multiple camera devices are required, as a single camera may not capture details of the movement being performed, especially when the user is not facing the camera frontally. To use a system composed of multiple cameras, it is necessary to apply a calibration process in order to obtain the parameters used to unify the different coordinate systems of each camera. Currently, there are devices with multiple cameras, but high cost, but not accessible. In this sense, the present work proposes the use of multiple kinect RGB-D cameras, performing a stereo calibration, by pairs of cameras, in order to determine the best configuration that contains minimal occlusion and self-occlusion problems inherent to the use of a single camera. In addition, the process of defining camera location and position aims to minimize interference between the devices used. To evaluate system performance, the composite skeleton from the fusion of the skeletons provided by each kinect was used, using the positions of the upper limb and head joints. The results show the best angular capture distances that correspond to a lower occurrence of the aforementioned problems, and the resulting fusion skeleton is more robust than when a single skeleton is used to evaluate the movement.

4
  • CAMILA SANTANA SILVA MATOS
  • Device for controlled atmosphere generation and measurement of ozone concentration.
  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • GEYDISON GONZAGA DEMETINO
  • IURI MUNIZ PEPE
  • LUIZ CARLOS SIMOES SOARES JUNIOR
  • POLIANA MOUSINHO MAGALHAES DE ALMEIDA
  • Data: Jul 13, 2018


  • Show Abstract
  • Although there are several commercial devices for ozone generation and for measuring the concentration of this chemical variety, generating a controlled atmosphere of ozone is still a challenge. Ozone, due to its high oxidative potential, can be used, for example, to reduce the time of induced oxidation measurements. This work describes the development of a device capable of generating a controlled atmosphere of ozone, determined by direct measurement of its concentration, through the measurement of the transmittance and the absorbance. The device can be integrated into equipment employed to measure rancidity levels. The apparatus consists of an ozone generator, an absorption cell that has a light source and a photodetector, a lock-in amplifier, a data acquisition along with an ozone generator triggering system, and a kitassato, used as a reservoir for the gas mixture. The optical sensor employed to measure the ozone concentration uses an LED as light source, with emission peak in the Chappuis band at 603 nm, and a large area photodiode as a photodetector. At the earlier phases of tests, the proposed device presented results of transmittance and absorbance consistent with the ones predicted in the literature. The values experimentally determined for the absorption cross section was 5,72 (± 0,17) (−0,46) x 10 − 25 m². In further phases of the tests, it was possible to produce different controlled concentrations of ozone following a linear profile with the slope around 75 ± 2 × 10−4 (𝑔/𝑚3)/(% 𝑑𝑜 𝑑𝑢𝑡𝑦𝑐𝑦𝑐𝑙𝑒). It has been demonstrated that it is possible to use the system to generate and measure a controlled atmosphere of ozone, which can be integrated into equipment where such an atmosphere is required.

5
  • VALNILTON EVILÁSIO DA SILVA
  • INTEGRATED SYSTEM FOR CALIBRATION OF HEART MONITORS IN ACCORDANCE WITH STANDARD ABNT NBR IEC 60601-2-27: 2013

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • ALLAN EDGARD SILVA FREITAS
  • CESAR ROGÉRIO MENEZES SILVA
  • IURI MUNIZ PEPE
  • JOSEMIR DA CRUZ ALEXANDRINO
  • Data: Jul 25, 2018


  • Show Abstract
  • The electrocardiogram (ECG) was invented by Willian Einthoven in 1902 and is the most used clinical procedure in the detection and diagnosis of arrhythmias, infarcts and even noncardiac anomalies. Because of its simplicity compared to other available techniques, it is often used as a research tool in long-term population clinical trials and in experimental drug trials that may affect cardiac functions. The cardiac monitor is one of the electromedical equipment available to display the ECG signals on the screen and as such must present technical compliance to the regulatory requirements of each country where it is marketed. ABNT NBR IEC 60601-2-27: 2013 is the Brazilian technical standard that establishes the safety and performance requirements of the electrocardiographic monitoring equipment and describes the compulsory tests for its certification in our territory. The procedures for performing calibration tests suggested by the standard are inherently manual and their systematic execution can induce sources of error to the measurements, influencing the judgment of the functionality of the apparatus. The present work consisted in the construction of an integrated and automated system for the calibration of cardiac monitors that presented, in the validation, uncertainties smaller than 1 \% and made possible the execution of the tests in a simplified, robust and reliable way.

6
  • MARCUS VINICIUS ELIZIÁRIO DE LIMA
  • Engineering Prototype for Fault Analysis in Three-phase Type Bldc Motors used in Dual Clutch Transmissions.
  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • ACBAL RUCAS ANDRADE ACHY
  • IURI MUNIZ PEPE
  • PAULO CESAR MACHADO DE ABREU FARIAS
  • Data: Aug 7, 2018


  • Show Abstract
  • Most automotive systems evolved from purely mechanical actuation mechanisms to more complex actuations controlled by electronic units and embedded processing. In this scenario, the use of brushless DC electric motors as actuators is predominant. These motors are better known by the English acronym Brushless Direct Current (BLDC). Although embedded electronics currently have an on-board diagnostic (OBD) system, this usually only helps to identify the subsystem that malfunctioned during the defective unit repair process without providing further details about the component which caused the loss of functionality or its failure mode, leading to inaccurate diagnoses and consequent unnecessary replacement of components in perfect working order. More accurate diagnoses, consistent and objective information are fundamental to the system of continuous improvement of products and processes. This paper discusses the process of developing a portable engineering prototype with the ability to perform diagnostics on BLDC motors used in dual clutch transmissions (DCT), from the automated determination of the impedance spectrum of the armature windings , focusing on the region of the resonance peak, aiming at the identification of anomalies in the magnetic circuit composed of rotor and stator, which can lead the motor to loss of total or partial functionality. The prototype also allows the diagnosis of embedded Hall effect sensors, responsible for the detection of the angular position of the rotor, using the analysis of the angular velocity of the motor axis, determined from the binary response of these sensors

7
  • LUAN SILVA SANTANA
  • Intelligent Wi-Fi Gates and Images Opening System
  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • CARLOS EDUARDO VIANA NUNES
  • FABIANO FRAGOSO COSTA
  • Data: Aug 24, 2018


  • Show Abstract
  • With the potential growth of devices and objects connected to the Internet, the Internet of things (IoT) has gained special attention in several areas of knowledge, being seen as the key technology for ubiquitous computing. Within the context of access control in parking lots, IoT is a promising reference and of great growth potential, by enabling the automation of repetitive processes and increase the safety of users of this site. In this way, this dissertation was developed with the purpose of developing a non-invasive system capable of assisting the control of parking vehicles via wireless mobile use of commonly installed technologies in public and private places, such as and mobile devices that have daily Wi-Fi connectivity user. From this, a system was developed that rules out the need for marking cars and other devices that are not in common use. For the user identification via Wi-Fi was used the NodeMCU ESP8266, which was programmed to function as an access point, allowing the MAC address to be read of the cellular network card at the time it is connected and then, enabling the opening of the automatic gate or gate for the registered user. For to perform a secure closing, a computer vision system was developed able to identify people or vehicles in the gate region. Prioritizing the bass computational cost was created two algorithms, the first using medium filter and the second employing Multi-Layer Perceptron neural network (MLP). From tests it was verified that the median filter as a classifier showed to be efficient for the group of images obtained during the day. However for the group of images captured during the night period, due to the low illumination in the region of the gate where the tests were performed, it was necessary to use an extractor and a more robust classifier. Therefore, we used the Local Binary Patterns (LBP) and another extractor proposed in this work for the RNA. Finally, a success rate of 71.6% was obtained for LBP and 92.6% with the proposed extractor.
8
  • WELLINGTON ASSUNÇÃO AZEVEDO
  • infrared adapter for integration of Internet home appliances
  • Advisor : ANTONIO CEZAR DE CASTRO LIMA
  • COMMITTEE MEMBERS :
  • ANTONIO CEZAR DE CASTRO LIMA
  • CARLOS EDUARDO VIANA NUNES
  • FABIANO FRAGOSO COSTA
  • Data: Aug 24, 2018


  • Show Abstract
  • The present thesis talk about the development of a technology transition system
    with low-cost Wi-Fi interface for insertion of infrared compatible electronics in the Internet
    of Things using the ESP8266 platform. The system was essentially developed using
    the ESP8266 microcontroller. The firmware proved to be the biggest challenge and was
    written in order to decode as many protocols as possible to replicate the signals emitted
    by electronic remotes. ESP8266 proved to be the most efficient option in conjunction
    with firmware techniques such as Interrupt, PCM, PWM and Power Management. The
    end product is a small system that can be directly coupled to an electronic or directly
    positioned to the receiver of that object, which connects to the Wi-Fi network of the
    environment and is controlled from an application or web page. The system does not
    influence the traditional use of the remote control, which can still be used. As a benefit
    of the proposed system, the platform can add even more functions to the ones that the
    electronics already offer at the factory, reallocating them to new concepts of technology
    like Smart Home and Internet of Things. It adds new capabilities such as remote access
    to any location that connects to the internet, unified multiple controls in one place,
    set custom operating times and schedules, smarter usable ways to reduce energy costs,
    among other functions depending on the user’s needs. It also assists in extending the
    service life of equipment relevance, reducing the need for their exchange. Air conditioning
    equipment was given special attention in order to propose a solution that would
    facilitate the projects of insertion of these equipments not only in this project, but also
    in others of the same area in future works.

9
  • WALTER GONÇALVES DE SOUZA FILHO
  • SYSTEM OF CONTROL OF THE DILUTION OF A TUNNEL CONSTANT VOLUME TUNER FOR COLLECTION OF MATERIAL PARTICULATED IN A TANK DIESEL ENGINES
  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • IURI MUNIZ PEPE
  • JOSÉ VALENTIM DOS SANTOS FILHO
  • LUIZ CARLOS SIMOES SOARES JUNIOR
  • VITOR LEAO FILARDI
  • Data: Sep 26, 2018


  • Show Abstract
  • This work presents the development of a closed loop control system capable of maintaining a constant dilution ratio between the air / exhaust gas mixture in tests using constant volume particle dilution (CVS) tunnel, in analyzes of particulates emitted by diesel engines. This control is necessary because, as the particulate material collection tests are carried out, the flow of treated air is reduced, due to the accumulation of dirt in its filters, causing its saturation. The project automated the particle collection bench previously developed in the Laboratory of Energy and Instrumentation - LEI of the Federal University of Recôncavo da Bahia - UFRB. As part of the development process, the instrumentation and power drive devices were constructed, revised and calibrated. The system management was performed by an embedded system with free platform microcontroller communicating with MATLAB®. The design and tuning of the controller were done after the mathematical model, based on the experimental data obtained in CVS. The implemented classical controller was evaluated using the basic performance metrics for both trajectory and regulatory (disturbance rejection) testing, with success in both cases.

10
  • CAIO CRISTIANO BARROS VITURINO
  • Anti-collision system applied to manipulator robots

  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • LEIZER SCHNITMAN
  • ANDRE GUSTAVO SCOLARI CONCEICAO
  • OBERDAN ROCHA PINHEIRO
  • JOSEMAR RODRIGUES DE SOUZA
  • CÉSAR AUGUSTO PEÑA FERNÁNDEZ
  • Data: Oct 3, 2018


  • Show Abstract
  • Interest in the development of anti-collision robotic systems has grown exponentially in recent years and with it, several advances in algorithms of route planning have been noted. These systems generate free-of-collision routes with static or dynamic objects in the robot's work area and have been widely applied in robots that perform some kind of autonomous activity. Artificial Potential Fields (CPA) is a route planning technique that has been the focus of improvements in recent years due to its simplicity of application and efficiency in real-time systems, as it does not require a global mapping of the area of of the robot, in addition to its compatibility in several types of robots. Despite their efficiency, CPAs are susceptible to local minimum problems of different natures, such as: Non-Reachable with Obstacles Nearby (GNRON) and Reacharound Local Minimum Problem (RLMP). To solve the problem of GNRON, it is proposed an improvement of the CPAs, through an adaptation of the Adaptive Artificial Potential Fields, so that they are applicable in manipulating robots. To solve RLMP problems, the existing Subgoal Selection, Goal Conguration Sampling and Convex Hull algorithms are used. In addition to the above problems, CPAs do not adjust the gains of repulsive forces dynamically. This problem contributes to the robot not reaching the goal when it is positioned within the area of influence of the obstacle. A method is proposed to estimate the repulsive force gain of the CPAs dynamically in order for the robot to reach the target even when it is positioned within the area of influence of the obstacle. The V-REP and MATLAB software are used to prove the validity of the proposed improvements.

Thesis
1
  • VALDIR LEANDERSON CIRQUEIRA DE OLIVEIRA
  • A proposed solution to the Dial-a-Ride Problem
  • Advisor : LEIZER SCHNITMAN
  • COMMITTEE MEMBERS :
  • ANGELO AMANCIO DUARTE
  • CARLOS ARTHUR MATTOS TEIXEIRA CAVALCANTE
  • ILCE MARILIA DANTAS PINTO
  • LEIZER SCHNITMAN
  • MARCIO FONTANA
  • Data: Jul 27, 2018


  • Show Abstract
  • This work aims to contribute to the development of solutions for the planning of people transportation. The characteristics involved in transportation planning problems are extensively studied in a branch of the Operational Research known as Vehicle Routing Problem (PRV). The PRV is derived in several other specific problems depending on the context in which they are inserted. When it comes to transporting people, as is the case study proposed in this paper, the characteristics of the problem are included in the PRV variation known as the Dial-a-Ride Problem or the Dial-a-Ride Problem (DARP). Most of the studies carried out on DARP are directed to the application in the transport of a certain target public, such as: patients in medical treatment, elderly, wheelchair users, people with special needs (from home to hospitals, clinics, etc. and vice versa ). This work presents a new computational approach based on Fuzzy Logic, Reinforcement Learning and Agents as a solution proposal for the static DARP with heterogeneous vehicle fleet. This approach considers some variables such as: distance and average time, comfort, availability of drivers and vehicles, amount of demand, load capacity, road condition and number of passengers as basis for decision making. A new fuzzy model was developed to assist in decisions about how best to organize requests and choose the best vehicle for each. A Q-Learning Enhancement Learning algorithm is used to generate the routes to meet the requests for transportation. Eight test cases are presented, using real and fictitious data, as a case study for the validation of the proposed solution. The results found, based on established quality criteria, such as: comfort, quantity of requests, average time and distance, indicate that the proposed solution is adequate for most of the analyzed scenarios.
2017
Dissertations
1
  • WELLINGTON LACERDA SILVEIRA DA SILVA
  • Defect and Consensus Detectors in Partitioned Synchronous Distributed Systems Subject to Byzantine Faults.
  • Advisor : RAIMUNDO JOSE DE ARAUJO MACEDO
  • COMMITTEE MEMBERS :
  • ALIRIO SANTOS DE SA
  • LEIZER SCHNITMAN
  • RAIMUNDO JOSE DE ARAUJO MACEDO
  • VINICIUS TAVARES PETRUCCI
  • Data: Jun 7, 2017


  • Show Abstract
  • Cyberphysical systems are systems in which the physical and computational components interact and are interrelated on various scales of greatness. Classes of cyberphysical systems, such as health care systems, transportation systems, smatr networks, among others, are already available and have the potential to transform a society with the new urban and social services of today. On the other hand, such feelings can also be implicated in great criticality potential in relation to failures and in malicious alerts to these new infrastructures as an example of known attacks of malware such as Stuxnet. Several approaches to the reliability problem (dependability) for systems understand the properties of a computational component and model aspects of dependability at this moment component is a feasible approach. Thus, we propose the application of a class of cyberphysical systems that can be modeled as systems distributed by partitioned systems - such as cyberphysical systems with WAN topology of LANs, which is common in SCADA systems with distributed plants and in applications such as intelligent networks . This dissertation presents the study and parts solutions for defect detectors and a consensus algorithm with adaptive drivers, in partitioned synchronous systems, or other offer resilience to Byzantine or arbitrary fault and outperform the conventional 3f + 1 processes for up to 50% failure.
Thesis
1
  • ITA TEODORO DA SILVA
  • CLOSED CIRCUIT OF FORCED CIRCULATION OF DUCTS BY OIL:
    INTEGRATION OF INSTALLED FACILITY AND ULTRASSOM DEPARAFINATION STUDY

  • Advisor : IURI MUNIZ PEPE
  • COMMITTEE MEMBERS :
  • GERMANO PINTO GUEDES
  • IURI MUNIZ PEPE
  • IVAN COSTA DA CUNHA LIMA
  • MARCIO ANDRE FERNANDES MARTINS
  • MARCUS VINICIUS SANTOS DA SILVA
  • Data: Dec 7, 2017


  • Show Abstract
  • -The deposition of paraffin in ducts is one of the big problems faced by the petrol industry during the production, transportation and storage of petrol. The acumulation of paraffin cristilized in the walls of the pipes, leads to the loss of force in flow on and, consequently the increase in the power necessary for the system of bombardiment, when the decrease of flow rate or a situation of extreme and complete obstruction of tubulation doesn’t happen, causing disorders, waste and decrease of production rythim. Mechanical methods of brushing, washing, scraping, chemical attack, warming, are some of the most common methods that dispose the industry to combat and try to overcome this obstacle in the production and petrol transportation. Research centrers make effort to understand the base parameters of this phenomenon and develop models that offer great precision in obstruction prevision of transportation lines of petrol by the crisitalization and deposit of paraffin. In spite of this, there are still limits not yet overcomed concerning the understanding of the variables and mechanisms involved in the process of deposition of paraffin in ducts. The objective of this research was to verify a possibility of data collection and information, referring to the deposition mechanisms of paraffin in lines of production and transportation of petrol, in a laboratory that would produce in a realistic scale of parameters, the stages and the phenomenon of flow of petrol in the field of oil Industry. Materials and equipments with compatible dimensions with those practised in the field were used. This was due to, as it is believed that, the more the experimental system of parameters resembles the real ones, the date and information collected, without mentioning the final results of the given investigation, reach the highest level of confiability as regards to prevision of the dynamic of the deposit of paraffin in the pipes. Initially, some tests of dewaxing were carried out using the cavitation provoked by ultrasonic transducers joined to tanks. After that, a line of paraffination in realistic scale was projected and build, where parameters related to the flow of oil and paraffination of ducts would be reproduced and measured. The line also served as base for the development of a temperature sensor and for initial tests of the system of dewaxing using ultrasonic necklaces.

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