Dissertations/Thesis

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2023
Dissertations
1
  • RODRIGO DE PAULA FONSECA
  • Application of the DMAIC method to propose improvements in a basic health unit in the city of Itajubá-MG

  • Advisor : LEONARDO ALBERGARIA OLIVEIRA
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • LEONARDO ALBERGARIA OLIVEIRA
  • ROSINEI BATISTA RIBEIRO
  • Data: Jun 16, 2023


  • Show Abstract
  • The DMAIC methody (define, measure, analyze, improve and control) is a tool, originating from Six Sigma, which aims to improve organizational processes, making them more efficient. Thus, this work proposed the application of the DMAIC methody in a basic health unit in the city of Itajubá-MG. The objective of the research was to map the care process at the UBS, analyze the service times, understand the organization of the environment and its processes to identify the main problems and propose measures and actions to reduce the time of care for patients and processes. The method was classified as an action research and followed the DMAIC tool, consisting of five phases: define, measure, analyze, improve and control. In the “define” phase, there was first the characterization of the unit. In the “measure” phase, data were collected from the health center and analyzed. In the “analyze” phase, problems at the health center were identified, where it was found that there was a considerable waiting time for patients. In the “improve” stage, suggestions were proposed for UBS. In the last step, “control”, tools were suggested for standardization and control of future processes. Several quality tools were applied, such as SIPOC, control charts, Ishikawa diagram, among others. The method made it possible to achieve the proposed objectives, where it was possible to know in depth the service process at the health center, identifying some problems, such as the lack of doctors and professionals, system failures, lack of standardization of activities, bureaucracy, use of the system in a unnecessary and lack of patient information. Proposals to improve service at the health center consisted of using the 5W2H tool with the elaboration of an action plan with the exposition of several measures. With the use of a future state value stream map, it was found that the implementation of measures could lead to a lead time reduction of more than 22%.

2
  • WANDER PINTO RIBEIRO
  • APPLICATION OF MEAN SQUARED ERROR FOR ROBUST OPTIMIZATION IN END MILLING OF STAINLESS STEEL DUPLEX UNS S32205

  • Advisor : TARCISIO GONCALVES DE BRITO
  • COMMITTEE MEMBERS :
  • EMERSON JOSE DE PAIVA
  • LEONARDO ALBERGARIA OLIVEIRA
  • MANOEL CLEBER DE SAMPAIO ALVES
  • TARCISIO GONCALVES DE BRITO
  • Data: Jul 12, 2023


  • Show Abstract
  • Research on the end milling of duplex stainless steel has gained prominence due to the challenges posed by its low machinability characteristics. Duplex stainless steel exhibits low thermal conductivity, high toughness, and a high rate of work hardening. To ensure a high final product quality, it is crucial to carefully plan the milling process to minimize tool wear during machining while maintaining good productivity indicators. The objective of this study was to perform a multi-objective robust optimization of the face milling process of duplex stainless steel UNS S32205. The experiments were conducted using a central composite design, combining the control variables: cutting speed, feed per tooth, depth of cut, and width of cut, and the noise variables: flank wear, fluid flow, and fluid concentration. The response variables evaluated were the surface roughness Ra and Rt of the machined part. Response surface methodology, robust parameter design, and mean squared error techniques were applied. Subsequently, the effects of control and noise variables, as well as their interactions, were analyzed and discussed. Cutting speed had the most significant influence on roughness Ra, while feed per tooth particularly affected roughness Rt. The obtained R_a values ranged from 0.243 to 1.097 µm, and R_t values ranged from 1.800 to 7.058 µm. The optimization of the mean and variance of each desirable characteristic, as well as the optimization of mean squared error, were performed. As a result, 21 Pareto-optimal solutions were obtained, contributing to the improvement of surface quality and productivity in the milling process. For confirmation tests, an orthogonal Taguchi arrangement (L9) was used to obtain optimal setups capable of mitigating the influence of noise variables, validating the suitability of the proposed methodology.

3
  • RENAN DELGADO CAMURÇA LIMA
  • Neural Networks Applied in Sharpe Ratio Forecasting: Evidence in Ibovespa Components

  • Advisor : HENRIQUE DUARTE CARVALHO
  • COMMITTEE MEMBERS :
  • MICHEL CARLO RODRIGUES LELES
  • HENRIQUE DUARTE CARVALHO
  • LEONARDO ALBERGARIA OLIVEIRA
  • Data: Jul 14, 2023


  • Show Abstract
  • The application of neural network models for selecting assets for investment portfolios using the Sharpe ratio has gained the attention of researchers. This study aims to apply neural networks in predicting the Sharpe ratio for investment portfolio selection. Through a literature review, the methods used in portfolio construction, optimization techniques, and neural network structures employed in this context are identified. The construction of prediction models requires the collection and preprocessing of historical data on financial assets and economic indicators. The portfolio selection process is divided into two stages: optimization based on the Sharpe ratio and portfolio selection using neural networks to predict the portfolio with the best performance in the next period. The performance evaluation is compared to the Bovespa index. The results show that the unconstrained model performs better in terms of optimization time and Sharpe ratio. Neural networks, although not surpassing the portfolios, demonstrate superior performance compared to the Ibovespa index. The LSTM+Bahdanau Attention neural network achieved the best performance. These findings contribute to the advancement of knowledge in the field of finance and highlight the potential of neural networks in investment portfolio selection.

4
  • DEISE SANTOS MADEIRA
  • Dosing Optimization of Mortars Produced with Iron Ore Tailings Using Response Surface Methodology

  • Advisor : TARCISIO GONCALVES DE BRITO
  • COMMITTEE MEMBERS :
  • CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • EMERSON JOSE DE PAIVA
  • ROGÉRIO SANTANA PERUCHI
  • TARCISIO GONCALVES DE BRITO
  • Data: Jul 17, 2023


  • Show Abstract
  • The construction industry together with the mining sector, especially the areas responsible for the extraction of metallic substances, are currently directly responsible for a significant portion of the environmental impact due to the high consumption of raw materials. With the need to rationalize natural resources, new proposals for the use of recyclable waste have been gaining scale with the development of dosages to improve the construction process, with special emphasis on the civil construction sector. Millions of tons of iron ore tailings (IOT), a by-product of iron ore processing, are discarded annually. Given this scenario, this work aimed to propose a new use for IOT in partial replacement of natural aggregates for coating mortars, simultaneously varying the water/cement ratio and additive content of the composition. The proper specifications of flexural tensile strength (Rt), compressive strength (Rc) and tensile bond strength (Ra) were evaluated in comparison to the traditional system. The strategy of this work is to combine Operations Research techniques for multiple response optimization, evaluating the interference of each isolated factor and proposing the best configuration for mortar dosage. The Experimental Design, based on the Central Composite Design (CCD) considered 3 control variables: replacement content of iron ore tailings (IOT), additive content (ADT) and water/cement ratio (W/C). Principal Component Analysis (PCA) and Desirability function were also used in the search for the ideal answer. The mortar dosage optimization indicated that the controllable parameters should assume the following configuration: IOT = 27.63%, ADT = 1.08% and W/C = 0.80, with mortar resistance values in the hardened state equal to Rt=11.38 MPa, Rc = 21.67 MPa and Ra = 0.55 MPa. The values obtained after the optimization are in accordance with the norms that define the mechanical and rheological requirements for mortars and compatible with the resistance of standard coating mortars. Confirmation experiments carried out validated the applied modeling, showing that the real optimal results are close to the optimized results.

5
  • WELBERSOM SILVA VIANA
  • ANALYSIS OF THE VALUE PERCEIVED BY THE GRADUATE STUDENT AT A PUBLIC HIGHER EDUCATION INSTITUTION

  • Advisor : ANA CAROLINA OLIVEIRA SANTOS
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • CARLOS EDUARDO SANCHES DA SILVA
  • CARLOS HENRIQUE DE OLIVEIRA
  • JANAINA ANTONINO PINTO
  • Data: Aug 14, 2023


  • Show Abstract
  • Seeking quality by adding value for the student can be very beneficial to higher education, not only from a financial point of view, but mainly from an institutional point of view. This search for value generation aims to attract and retain students. For this very reason, it is of paramount importance that higher education institutions (HEIs) have the strategic goal of maintaining a lasting relationship with their students. Currently, HEIs are faced with a paradox: on the one hand, the offer of higher education is growing rapidly, with the opening of several institutions, in addition to the fact of the popularization of higher education, granting wide access to students. However, on the other hand, each year there are increasing contingencies for education. Given this scenario, the search for quality adding value to the student is shown as a crucial means of differentiation for the creation of sustainable competitive advantage, aiming to attract and retain students. In a first step of this study, a systematic literature review was proposed in order to identify the components of perceived value cited in the literature. According to the research, in general, what most motivates the work is the search for the improvement of the relationship between institution and student. Subsequently, the survey methodology was adopted in order to collect, within the university, the student expectation about the perception of value. For the analysis of the data obtained in the research, the GRA method was used. This methodology makes it possible to synthesize and classify the various variables studied into useful information, demonstrating the best alternatives for the process. In general, the results can help higher education institutions to identify what adds value to the provision of services, according to the student. In this way, the GRA allowed for a ranking in which the quality dimension, the social dimension and the cost dimension were the three dimensions most considered by students, respectively.

6
  • MARIA LUIZA SOUZA CAETANO
  • Challenges and success and failure factors in implementing agile methods in organizations: A systematic literature review

  • Advisor : TABATA NAKAGOMI FERNANDES PEREIRA
  • COMMITTEE MEMBERS :
  • PAULA KARINA SALUME
  • LEONARDO ALBERGARIA OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Nov 30, 2023


  • Show Abstract
  • It is essential to ensure good work practices so that the results of organizations are increasingly productive. Putting the customer at the center and really understanding what they really need is a fundamental practice to ensure the competitiveness of organizations. In this way, it is necessary to ensure excellence in its processes and, more than ever, to attest that its results are in coherence with the needs of customers, which can change at any time. Consequently, the flexibility factor also becomes extremely essential for organizations. As a result, the use of agile methodologies, which bring adaptability in their ideals, has been gaining strength and becoming increasingly popular in companies, but what challenges can organizations face during implementation? What are the success and failure factors linked to this change? To answer these questions, the present study aimed to identify the most cited challenges in the adoption of agile methods by organizations and their main factors of success and failure, questions were also addressed about the definitions of success and failure, how to categorize agile organizations and asked if agile approaches bring a good result to any institution. To this end, a systematic literature review (RSL) was carried out using the stages of planning, conduction, documentation and execution. A total of 57 articles were identified that helped to find the key questions that explored the theme addressed. After the analyses, it was identified that the main challenges cited are Communication, Organizational Culture, Technical Challenges, Lack of Support from Senior Management, Little Experience/Need for Training, Processes and Team Resistance to Change. The main factors of success and failure are Communication, Culture, Team, Facilitation, Leadership, Process and Result.

2022
Dissertations
1
  • PATRICIA FREDERICO
  • Economically optimal mix of raw materials in blast furnaces using discrete event simulation and the linear programming model

  • Advisor : EMERSON JOSE DE PAIVA
  • COMMITTEE MEMBERS :
  • EDUARDO MIGUEL DA SILVA
  • EMERSON JOSE DE PAIVA
  • TARCISIO GONCALVES DE BRITO
  • Data: Feb 17, 2022


  • Show Abstract
  • Blast furnaces are continuous production equipment intended to melt and reduce iron ore in the presence of charcoal or coke and fluxes, for the production of pig iron. Maintaining the continuous supply of raw materials is a critical and relevant factor in this process. In addition, the selection and preparation of these raw materials are of great importance for the steel production strategy, as they directly impact the quality of the product produced and the associated cost. In order to optimize the production of this equipment, maintaining its continuous supply and competitive price, this work aims to investigate the supply process of the blast furnaces, especially the unloading of charcoal, contemplating from its reception, unloading and supply of the silos. , until its storage in the cells, and identify the ideal mix of raw materials that guarantee the quality of the final product with lower production costs. The analysis method was based on a hybrid approach between modeling and simulation of discrete events, using the Promodel software, and optimization, linked to linear programming, from a Linear Programming model. The result obtained with the simulation was the best visualization of the unloading system, thus enabling corrective actions to be taken in the input configuration of vehicles transporting charcoal, in order to optimize their unloading and, consequently, guarantee the supply of material. press steadily. In addition, mathematical modeling and linear programming made it possible to study the best ore mix option for load configuration, linking commercial conditions of cost and availability and appropriate chemical composition restrictions, which were proven through tests with loads and real settings.

2
  • HATHOS GARCIA DIAS
  • PRIORITIZATION OF BEST PRACTICES OF PROJECT MANAGEMENT IN THE WORKS OF A FEDERAL PUBLIC UNIVERSITY

  • Advisor : CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • COMMITTEE MEMBERS :
  • CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • CARLOS EDUARDO SANCHES DA SILVA
  • KÍVIA MOTA NASCIMENTO
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Jun 29, 2022


  • Show Abstract
  • Brazilian public works are generally viewed negatively by the population, this image is mainly linked to construction stoppages, delays, extrapolation of costs and poor quality. Efficient project management has favored public organizations in improving the performance of construction management. This dissertation presents a proposal to prioritize the implementation best practices of project management practices as a way to improve the management processes of the works of a federal public university. The research used the Soft System Methodology (SSM) as the main methodology, supported by the application of a Systematic Literature Review (SLR) and the GUT Matrix to prioritize good practices. A diagnosis of the main problems of the institution that are related to the management of the works was carried out. Aided by SLR, a conceptual model was built, containing 42 (forty-two) good practices applicable in public works, which can be used as a reference in future research on the subject. This model was validated by experts in the field through a questionnaire, which pointed out the most important good practices for the investigated context. Finally, the GUT Matrix tool was applied, which used the criteria of Severity, Urgency and Tendency, based on the evaluation of professionals who work directly with the builds, to propose good practices as priorities: (1st) “qualitative risk analysis” , (2nd) “requirements analysis”, (3rd) “contingency plan”, (4th) “stakeholder analysis”; (5th) “quality plan”; (6th) “analysis of the critical path method”; (7th) “project management models”; (8th) “lessons learned; (9th) “progress meetings”; (10th) “Project Management Software” and (11th) “Business Information Modeling”. Based on the order of prioritization presented in this dissertation, the administration of the institution will have greater basis to make decisions that aim to improve the management of the works carried out on the campus, aiming to reduce delays in the delivery of works and to have greater efficiency in the work performed by the servers.

3
  • THULIO EUGENIO PORTES DE ALMEIDA RICOMINI
  • Application of the Analytic Hierarchy Process in prioritizing customer value in the software development process

  • Advisor : ANA CAROLINA OLIVEIRA SANTOS
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • HENRIQUE DUARTE CARVALHO
  • HUGO JOSE RIBEIRO JUNIOR
  • ROBERTO SILVA NETTO
  • Data: Jul 18, 2022


  • Show Abstract
  • For the success in software development it is necessary to balance the objectives of suppliers with the needs of their customers; in this context, this work explores the prioritization of the dimensions of value for the customer in the development of software for fuel stations, being determined the main dimensions of value in the given context, as well as the division of dimensions into three subcriteria each, approaching the prioritization model of company decision-makers to the criteria of their customers. Thus, this research aims to present the main dimensions of value to the software customer for gas stations, comparing priorities with decision-makers and consumers, and presenting a value prioritization model for software suppliers for gas stations. For this, this work uses a systematic review of the literature to delimit the main dimensions of value according to the existing literature, answering how the value can be measured, what its main dimensions are, and what is the definition of value in the context of software development; following the dimensions are subdivided into three subcriteria each, the dimensions next to the subcriteria form the AHP model applied to 12 specialists divided between 6 decision-makers and 6 customers of a software company for posts, priorities are evaluated between the 12 responses and then between the two groups of decision-makers and customers. The available resource dimensions, costs, and delivery time are found as the main components of customer value in software development; available features are subdivided between software functionality, performance, and availability; cost subcriteria are fixed, variable and indirect costs; and delivery time was divided between deployment time, customization, and troubleshooting; the cost criterion is found as the leading dimension in the value composition for the customer, followed by the available resources and finally by the delivery time; when aggregate priorities are separated between decision-makers and customers there is a difference in prioritization, decision-makers having a greater relevance of available resources rather than costs, while customers point to costs as the main component of value; using the subcriteria is noted the availability of the software (as availability and troubleshooting time) as a point of attention for the software vendors. Finally, in the scenario of software development for gas stations, customer value is defined as the customer's qualitative perception of how well and how fast software can meet customer needs in contrast to the cost of software; there is also a need to expand research to other segments, to compare value prioritization in different user and product contexts.

4
  • EDUARDA CARVALHO PINTO COELHO
  • Analysis of e-learning factors in the perception of students of engeneering courses at the Federal University of Itajubá - Campus of Itabira

  • Advisor : CARLOS EDUARDO SANCHES DA SILVA
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO SANCHES DA SILVA
  • CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • LUCAS GUEDES DE OLIVEIRA
  • Data: Jul 25, 2022


  • Show Abstract
  • Considering the current reality of higher education institutions, recent research data has shown that the implementation of disciplines through distance learning is bringing benefits to both students and professors through greater flexibility in content delivery, increased standardization of teaching and the availability and accessibility of didactic learning material. In this sense, the present work seeks to identify and analyze the factors that influence the development of distance education disciplines in the opinion of the students, through a study of the application of this teaching modality cited in scientific publications and through a real verification in the place object of study. The choice of theme was justified, firstly, due to the restrictions on the movement of people and social isolation imposed by the world pandemic of COVID-19 that prevented the face-to-face functioning, not only of educational institutions, but all commercial establishments around the world. Second, due to the substantial increase in enrollments in higher education courses offered in the distance education modality, since before the emergence of the pandemic. Finally, due to personal issues of the author who experienced the experience of being a student during the pandemic period. An applied research was carried out, with an explanatory objective and a quantitative approach, which includes a Systematic Review of the Literature to identify the critical success factors in the implementation of distance learning disciplines, complemented by a data collection through an interview with the students of the institution. It was concluded that the research responds to the proposed problem, showing that the factors related to the Teacher's Technical Competencies and their Training to Work in Distance Learning, the Student's Personal Interest in the Discipline, the Didactic Material and the Teaching Platforms Used are the most important to be considered in the implementation of distance education disciplines according to the students' view, still showing which of these factors are the most important and which ones are not necessarily so important in the opinion of the students interviewed.

5
  • ELAINE CRISTINA REIS SILVA
  • Relationship between school dropout and teaching practices: an exploratory case study in a higher education institution

  • Advisor : TABATA NAKAGOMI FERNANDES PEREIRA
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO SANCHES DA SILVA
  • ISABELA MAGANHA
  • MONA LIZA MOURA DE OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Aug 31, 2022


  • Show Abstract
  • According to the Federal Constitution of 1988, education is a heritage asset and, as such, it generates an obligation for the State to offer and guarantee quality, which implies the need for the State to invest public resources in order to meet the needs of the public. this demand. Given this scenario, school dropout is a worrying fact as it implies economic and social losses. Economic, in view of the loss of public and social investments, due to the fact that it implies the insertion of less prepared professionals in the job market. The present study is a research carried out in the advanced campus of a higher education institution in the interior of Minas Gerais, whose methodology was the case study of an exploratory nature. The research explores the relationship between school dropout and teaching practices, aiming to diagnose the scenario presented in the institution under study. As the main source of information, the evaluation reports applied at the institution were used, considering the results from the report for the year 2015/2016, in which information from the researched campus was included. Based on the results presented for the dimensions dealt with in the institutional evaluation reports, especially the one that analyzes questions related to the Policy for Teaching, Research and Extension, it can be concluded that the teaching practices adopted do not have a negative impact on the students' decision to drop out of the institution. The percentages presented in the statements evaluated in that dimension denote a high level of students' satisfaction in relation to teaching practices, contributing to the feeling of integration and belonging and reflecting on the dropout rates in the institution. As an additional result of the work, a framework was proposed whose steps can be followed in order to perform similar future works, using the CPA reports as sources of information.

6
  • NADINE TRAVAGLIA DOS SANTOS PEREIRA
  • Reduction of the rework rate through the application of the DMAIC method: A case study in an industrial laundry

  • Advisor : ISABELA MAGANHA
  • COMMITTEE MEMBERS :
  • ISABELA MAGANHA
  • LEONARDO ALBERGARIA OLIVEIRA
  • SIMONE CARNEIRO STREITENBERGER
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Nov 30, 2022


  • Show Abstract
  • Industrial laundries, one of the representatives of the textile sector in Brazil, are an important support service for society, as they support the operation of hospitals, industries, hotels and others. However, these industries face management difficulties and have to deal with a lack of operational controls. In this sense, an integrative literature review was carried out to understand the context in which industrial laundries are inserted. The results of this review showed that there are few studies related to operational controls and the use of performance indicators to monitor the production processes of industrial laundries. Based on this result, a systematic review of the literature was conducted to analyze the use of performance indicators to control industrial laundry processes. This review focused on identifying which performance indicators are generally associated with the application of DMAIC method (define, measure¸ analyse, improve, control). DMAIC is part of the Six Sigma philosophy and serves as a standard roadmap to guide and facilitate the development of an improvement project, organizing the techniques used at each stage. The findings of the literature reviews made it possible to identify gaps and opportunities for future research in this area, among which the development of studies focused on improving production operations, the application of quality tools to improve production operations and the determination of indicators to control production operations and measure their performance. In order to contribute to fill these gaps, this work aims to reduce the rework rate in the process of cleaning the trousseau of an industrial laundry, appling the DMAIC method. The methodology adopted to achieve this was the case study, which was carried out in an industrial laundry in Belo Horizonte and the metropolitan region. The results of the case study made it possible to understand and analyze the flow of the trousseau washing process, in addition to measuring the rework rate, identifying the main causes and proposing actions to reduce it. Thus, the DMAIC method, as well as the use and development of performance indicators proved to be useful and capable of helping to improve production processes. Finally, this work had practical contributions to the laundry studied, which reduced the average percentage of rework from 3% to 1.6%, which represents savings of R$17.25 per day, and R$6295.62 per year.

7
  • RENATA SANTANA NEPOMUCENO
  • Analysis of Organizational Culture through the perception of servers on the Campus of a Federal University through the application of OCAI

  • Advisor : HENRIQUE DUARTE CARVALHO
  • COMMITTEE MEMBERS :
  • HENRIQUE DUARTE CARVALHO
  • ISABELA MAGANHA
  • MONA LIZA MOURA DE OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Dec 16, 2022


  • Show Abstract
  • The organizational culture is built through the habits and beliefs shared in an organization, created by norms, values, attitudes and expectations of its members. In addition to representing the predominant mindset in an organization, it represents the way of thinking and acting, and the perception of its managers and employees. It is considered as an element of communication, and its study and understanding are extremely important within organizations, in search of understanding the organizational functioning. Public organizations have been becoming aware of the importance of organizational culture in institutions as a means of achieving objectives. This research was carried out with the objective of identifying and analyse the organizational culture currently perceived and the organizational culture desired by professors and technical administrative servants on the campus of a federal university. The OCAI instrument was used as a tool for diagnosing culture and, through its results, it was concluded that, as presented in the literature, the chosen tool is viable and effective in diagnosing organizational culture. It was found that there is synergy between the class of professors and administrative technicians, since their perceptions and desires regarding the organizational culture were the same. However, a discrepancy was found between the culture perceived and desired by them, which demonstrates dissatisfaction on the part of employees regarding the culture that surrounds the environment in which they carry out their activities. The results achieved indicate the need for more attention by management to a more collaborative organizational culture that values people, and the need for a possible cultural change within the organization, taking into account the perception and desires of employees.

2021
Dissertations
1
  • CARLOS FILIPE NASCIMENTO
  • OPTIMIZATION OF MACHINING PARAMETERS OF STAINLESS STEEL SUPER DUPLEX UNS S32750 USING RESPONSE SURFACE METHODOLOGY

  • Advisor : TARCISIO GONCALVES DE BRITO
  • COMMITTEE MEMBERS :
  • EMERSON JOSE DE PAIVA
  • LEONARDO ALBERGARIA OLIVEIRA
  • ROGÉRIO SANTANA PERUCHI
  • TARCISIO GONCALVES DE BRITO
  • Data: Jun 22, 2021


  • Show Abstract
  • The improvement of processes and products has increased substantially, due to the competition established between organizations, expanding quality control and the search for process optimization. Among these processes, in manufacturing, the turning of super duplex stainless steel UNS S32750 (SDSS) stands out, which has deserved special attention due to its excellent properties, mechanical and corrosion resistance, allowing its employability in diverse tasks, especially in the petrochemical industries and in processes with incidence of chlorides. Understanding controllable parameters is essential for improving quality and represents a gap in the literature and a research opportunity. Thus, in this work, it is proposed to combine known statistical tools to obtain optimization of multiple responses, in order to identify these parameters, seeking optimal initial conditions: o Design of Experiments, using a central composite design (CCD); principal component analysis (PCA) for dimensionality reduction; and the Desirability function, in determining a trade-off between the response variables. For processes of this type, it is common to evaluate the quality by the surface finish resulting from the machined parts. The study was conducted from an experimental design involving 3 control variables (xi): depth cut, feed rate and speed rate. As result, it was established that the optimal conditions for the process would be ap = 0.63 mm, f = 0.08 mm/rev and vc =178.5 m/min with calculated roughness equal to Ra = 0.235 μm, Ry = 1.084 μm and Rt =2.379μm. At the end, a confirmation experiment was carried out, in order to demonstrate the ability to obtain parts with acceptable levels of roughness, from the process parameters obtained by the optimization procedure. The results of the experimental confirmation rounds point to the good adequacy of the proposal.

2
  • FABIANA FERREIRA SILVA VIEIRA
  • Preventive maintenance management of building infrastructure: an research-action in an iron ore company
  • Advisor : TABATA NAKAGOMI FERNANDES PEREIRA
  • COMMITTEE MEMBERS :
  • JOSE ARNALDO BARRA MONTEVECHI
  • MONA LIZA MOURA DE OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Jul 21, 2021


  • Show Abstract
  • The international business scenario is becoming increasingly competitive. Companies want to improve processes, which highlights the need to reduce waste and enhance results. Mining follows this context and has brought high competitiveness. The production of iron ore is obtained through drilling, blasting, loading, transport and infrastructure, the latter being fundamental, since infrastructure failures lead to inefficiency in production management. Therefore, improving building infrastructure production management processes in the Brazilian mining sector implies increasing the productivity of organizations. Thus, the issue of this work was reached: What results can the implementation of preventive maintenance in building infrastructure bring to the production management processes in iron ore processing? The general objective was to use production management tools to implement preventive maintenance in the area of building infrastructure in an iron ore processing company. To conduct the work, 3 complete cycles of research-action method were used as methodology. As a result of this dissertation, it was noticed that there is a lack of theoretical production within the theme, and the existing studies are recent. For the company under study, the project provided intelligent resource management, achievement of the company's strategic initiatives with effective management of indicators automatically and online, and greater employee and customer satisfaction, also notable is the Adherence to Call Answering Indicator, which surpassed the target set for 2020, reaching 93.51%. And although it was not raised as a project objective, the implementation also brought benefits related to the reduction of maintenance material costs, with a reduction of 60.40% in the first quarter of 2021.

2020
Dissertations
1
  • EFIGÊNIO RODRIGUES DA COSTA JÚNIOR
  • REDUCING HOURS WITH CORRECT MAINTENANCE OF DIESEL ENGINES FROM RELIABILITY ASSESSMENT: AN ACTION RESEARCH IN THE MINING BRANCH

  • Advisor : EMERSON JOSE DE PAIVA
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • EMERSON JOSE DE PAIVA
  • PEDRO JOSÉ PAPANDRÉA
  • Data: Jun 24, 2020


  • Show Abstract
  • In order to obtain competitive advantages, organizations seek to review their strategies in order to guarantee production at reduced costs, without, however, compromising quality. Within mining companies, production may be compromised if the equipment used is not reliable, especially when it comes to haul trucks. To guarantee the reliability of this equipment, maintenance planning and control has been strategically highlighted in these organizations, aiming at the balance between reliability and maintenance costs. And, in the search for this balance, several studies have pointed out the advantages of implementing the Six Sigma methodology to reduce variability, increase the levels of reliability and ensure the availability of assets. In this context, this work sought to reduce the number of hours with corrective maintenance of diesel engines for off-road equipment, through the application of Six Sigma methodology tools and process reliability assessment, based on a research cycle. -action, based on the concepts of the reasoning map in conducting projects of this size. It started by defining the problem, surveying the history of corrective engine failures and stratifying possible factors that could interfere with their reliability. Then, the causes were established, the necessary actions to eliminate or mitigate them, recording the results. To verify the effectiveness of the results, the methodology used was replicated in a maintenance process for L1850 loaders to reduce costs in the acquisition of lubricating oil. The results demonstrated the benefits of using the Six Sigma methodology tools, combined with reliability analysis, due to the significant reduction in defects in diesel engines, the costs with corrective and predictive maintenance, in addition to the reduction in costs with the purchase of lubricating oil.

2
  • SCHEIRLA TEIXEIRA SANTOS
  • Application of Value Stream Mapping in the bidding processes of a public university

  • Advisor : TABATA NAKAGOMI FERNANDES PEREIRA
  • COMMITTEE MEMBERS :
  • ISABELA MAGANHA
  • MONA LIZA MOURA DE OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • Data: Nov 20, 2020


  • Show Abstract
  • The slowness in the progress of administrative bidding processes in the public sector can lead to delays in the provision of services and often waste of time and resources that could be directed to other activities. Therefore, analyzing procedures that can bring agility and efficiency to the activities becomes a fundamental action in the strategic management of the institutions. The Lean Office, which aims to improve workflow and eliminate waste in administrative areas. Lean uses the Value Stream Mapping tool to identify waste in any process. In this sense, this work aimed to understand the applicability and effectiveness of this technique, used in the bidding sector of a public university, answering the following question: what activities add value to the bidding procedures carried out by the public administration? For that, action research was used as a research methodology, oriented towards solving the research problem, adopting the process mapping tool to visualize and understand the activities performed, with the identification of its value flow. The main results of this implementation were found to be a significant reduction in waiting times and, consequently, shorter lead time and improved efficiency in the execution of bidding processes, concluding that, even with the bureaucratic complexity of public sector administrative procedures, the application of the Mapping the Value Stream can be carried out with positive gains to improve activities.

3
  • ANA PAULA ROBERTO MARMOL
  • APPLICATION OF VALUE FLOW MAPPING IN THE ANNUAL INVENTORY PROCESS OF A FEDERAL HIGHER EDUCATION INSTITUTION THROUGH THE SOFT SYSTEM METODOLOGY

  • Advisor : ANA CAROLINA OLIVEIRA SANTOS
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • GABRIELA DA FONSECA DE AMORIM
  • ROBERTA ALVES
  • Data: Dec 7, 2020


  • Show Abstract
  • This work aims to apply the Lean tool Value Stream Mapping (VSM) on the annual inventory of movable assets in a Brazilian institution. Soft Systems Methodology (SSM) will be used to conduct the stages of defining the product family, making the map of the current state and preparing the map of the future state. In this way, it will be possible to identify wastes and propose the implementation of improvements in the studied process, thus contributing to the increase in the Value Added Ratio (VAR) for its customers. The process elaborated in the future state map, presents improvements regarding the elimination of waits, rework and the standardization of activities, with reduction of the process Lead time from 115 days to 12 days, which represents a drop of 89.5% in process time and a 31% increase in the value-added rate. The limitation of this work is that it is a unique case and, therefore, it is an investigation of specific problems. As a way of improvement, the future state map was prepared aiming at improving the process and for that, an implementation plan was proposed. In addition, Standard Operating Procedures (SOPs) were developed and implemented for asset control activities and the annual inventory process, which has already promoted efficiency gains in the process, in the hiring of human resources, as well as the positive motivational impact of people involved in the process and compliance with current legislation. So, it has to be said that in terms of practical contribution, this work meets the need to improve the excellence of public services, as well as to reduce their costs, in addition to being able to serve as a reference for application in other processes. In terms of theoretical contribution, it is clear that this empirical study may help to disseminate the application of Lean Office concepts in public services and contribute to reducing the gap in the literature in this area.

4
  • LEONARDO GERALDO LEITE
  • TECHNICAL FEASIBILITY ANALYSIS OF A COMPACT HYDRAULIC POSITIVE DISPLACEMENT PUMP, DOUBLE ACTING AXIAL PISTON, ACTIVATED BY A TRACTOR POWER OUTLET

  • Advisor : TARCISIO GONCALVES DE BRITO
  • COMMITTEE MEMBERS :
  • CARLOS EYMEL CAMPOS RODRIGUEZ
  • EDUARDO MIGUEL DA SILVA
  • RUBEN ALEXIS MIRANDA CARRILLO
  • TARCISIO GONCALVES DE BRITO
  • Data: Dec 15, 2020


  • Show Abstract
  • Hydraulic pumps assign energy to the fluid to transport it by flow from one point to another, converting mechanical work into energy for operation. Among the existing types of pumps, positive displacement piston pumps operate with low flow and high pressures, with the fluid displaced from suction to discharge in defined and continuous volumes. The use of these pumps presents the possibility of working with viscous fluids and with suspended particles, either in pressurization or atomization services according to the working fluid. The use of this type of pump in remote locations presents restrictions due to the size of the equipment and its peripherals, the type of drive and even its mechanical complexity regarding maintenance. The development of a prototype that can be used in situations of scarcity of resources and activated by the tractor itself encourages the possibility of saving time for certain agricultural tasks, as well as the practicality of using simple maintenance and handling equipment. This study aims to explore the technical feasibility of a positive displacement hydraulic pump, with a double-acting axial piston, driven by the power take-off of tractors of various types. The prototype under analysis has the advantage of a reduced size and high working pressure, ideal for spraying crops and transporting fluids between short distances, without using electricity. The pump casing was subjected to a computer simulation using the Finite Element Method (FEM), which showed stress concentrating points along the working body and other aspects related to safety factors, torsion in the casing and others. The prototype was tested at constant speed of 150 rpm, and also at constant speed of 300 rpm, presenting approximately 87 bar of working pressure before breaking off. The cracks found on the carcass during the failure analysis contributed with the computer simulation by the FEM, proving to be a reliable analysis. The prototype operating equations showed values for the average flow rate Q = 0.00029134 m³ / s, specific energy supplied to the liquid Y = 22155.878 J / kg and pressure drop in the valves 𝑯𝒂 = 0.9822 mca. Based on the information analyzed throughout this study from drawings, calculations and simulations, the developed prototype is technically feasible for agricultural applications since it presents reduced dimensions, adequate pressure and flow, and also simple mechanical requirements.

5
  • RODRIGO AUGUSTO DE FIGUEIREDO
  • Proposal for implementing the concepts of Lean Public Service in planning the contracting of continuing services of a Federal Institution of Higher Education

  • Advisor : ANA CAROLINA OLIVEIRA SANTOS
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • ISABELA MAGANHA
  • JOÃO EDÉRSON CORRÊA
  • Data: Dec 18, 2020


  • Show Abstract
  • Service management, with the objective of improving its efficiency and quality, finds in the Lean approach a possible solution to reduce waste and add value to customers. Within this process, the evaluation of tools that can be implemented and that can be applied in practice to improve the development of activities becomes a differential for the professionalization of the work of the Federal Public Administration bodies. In this sense, the present work aims to propose a plan to implement improvements and add value in the process of preparing the mandatory documents for bidding for the contracting of continuing services at Unifei Campus Itabira, through the application of the principles of Lean Public Service. The choice of the theme was justified by the success rates of the implementation of the Lean methodology highlighted in the literature, in view of the evident need of the Public Administration to improve its processes with the consequent reduction of costs, considering mainly the reduction in the costing budget of all Institutions Federal Higher Education Institutions in the country (IFES). As a methodology, a descriptive applied character research was carried out by conducting the stages of Design Science Research that includes a Systematic Literature Review to identify the tools and a prioritization of order of importance through the Analytic Hierarchy Process (AHP) technique, with based on the BOCR criteria (benefits, opportunities, costs and risks) and the consequent elaboration of the Value Stream Mapping. In terms of results, the research concluded that the application of Lean¸ principles and tools can be considered an opportunity for IFES to significantly reduce their costs in these processes, proving to be a satisfactory solution for quality improvement in the planning of contracting continuous services from Unifei Campus Itabira.

2019
Dissertations
1
  • ICARO SOUZA RIBEIRO
  • Proposal for implementation of Lean Production (LP) in a small furniture company in the city of Itabira-MG.

  • Advisor : CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • COMMITTEE MEMBERS :
  • CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • WAGNER RAGI CURI FILHO
  • Data: Oct 3, 2019


  • Show Abstract
  • This dissertation proposes the implementation of Lean Production (LP) and quality tools in a
    small furniture company in the city of Itabira-MG using Value Stream Mapping (VSM). The
    methodology adopted in the dissertation was the Soft Systems Methodology (SSM). This
    methodology has as principle the construction of conceptual models and the comparison of
    these models with the real world. The integration of the SSM methodology and the MFV tool
    resulted in a framework that guided the use of Lean concepts according to the SSM scientific
    guidelines, and represents a scientific result of this thesis. The results showed that the small
    company will get a clearer view of its processes. The improvements pointed out in the future
    maps indicate the reduction of wastes and the increase in productivity for the chosen family of
    products. The proposed future state map, considering the scenario with the acquisition of
    equipment, resulted in the reduction of: 15.6% in Lead Time; 38.7% in process bottleneck;
    31.2% in processing time. The productivity increased 18.8%. The barriers identified in the
    implementation of the action plan, based on the Lean philosophy, were the resistance of the
    operational team and the company's high management to new changes. These barriers are
    commonly encountered among the Small and Medium Enterprises (SMEs) regarding Lean. The
    action plan elaborated using the VSM provided the company the identification of priority
    actions, a better understanding of the sequence of actions to be taken, establishment of goals,
    attributions of responsibilities and the definition of deadlines.

2
  • TIAGO CAIXETA NUNES
  • Optimization of iron ore flotation parameters using Response Surface Methodology

  • Advisor : TARCISIO GONCALVES DE BRITO
  • COMMITTEE MEMBERS :
  • EMERSON JOSE DE PAIVA
  • NEYMAYER PEREIRA LIMA
  • TARCISIO GONCALVES DE BRITO
  • Data: Nov 13, 2019


  • Show Abstract
  • The reverse cationic flotation of quartz for particles smaller than 0,150 mm is the most important industrial processes of iron ore concentration for pellet feed production. With the depletion of mineral deposits with high iron contents and increasing demand for low ore contaminants for steel production, it is important to evaluate the effects of parameters that influence flotation performance. In this context, this research presents a proposal to apply an optimization method of flotation parameters for better utilization of available mineral reserves. Two experimental procedures involving process variables: depressor, collector and pH were employed to identify the optimal combination of these input variables to maximize metal recovery, keeping the silica (SiO2) content in the concentrate below to avoid quality penalization. In the first one, to identify the conditions of the process responses, a 23 full factorial design with three center points was used, totaling 11 bench flotation tests referring to samples in the flotation feed flow in a large iron mining company in Brazil. In the second, a Central Composite Design (CCD) designed with 17 flotation tests with a representative sample was used for a future feeding condition. To test this hypothesis, the results were used in the CCD and the analysis of variance, obtained was fit R^2 = 0.6972 for SiO2 content in the concentrate, R^2 = 0.9854 for Iron content in the tailing, R^2 = 0.9791 for iron recovery e R^2 = 0.9734 for mass recovery with 0.46% of SiO2 content in the concentrate, considering an upper limit of 0.50%. The optimization was performed using the Generalized Reduced Gradient (GRG) algorithm and obtained as a result 500 g/tfeed, 75 g/ tSiO2 and 9.80, for starch, amine and pH, respectively, and a calculated recovery value of 95.21% with a SiO2 content in the concentrate of 0.46%, with an upper limit of 0.50% in the concentrate. To confirm the results, a test was performed obtaining 93.86% for iron recovery and 0.51% of SiO2 in the flotation concentrate.

3
  • VITOR NICCHIO ARÇARI
  • Proposal for implementation of building maintenance management in a Federal Higher Education Institution

  • Advisor : CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • COMMITTEE MEMBERS :
  • ANA CAROLINA OLIVEIRA SANTOS
  • CARLOS AUGUSTO DE SOUZA OLIVEIRA
  • TABATA NAKAGOMI FERNANDES PEREIRA
  • WAGNER RAGI CURI FILHO
  • Data: Dec 6, 2019


  • Show Abstract
  • The delivery of a building to the owner cannot be considered as the end of the building process, because if the goal is to generate user satisfaction and maintain the projected useful life, the process must continue with the building maintenance. In this scenario, public agencies are a major challenge, as they own or are responsible for a large number of buildings, built at different times, with different construction technologies and typologies, generally dispersed over a wide geographic territory. This dissertation proposes the implementation of building maintenance management in a Federal University Campus, which has around 20,000 square meters of built building area. For this, a bibliographic survey was conducted addressing the theme of building maintenance management. The scientific methodology used was the Soft Systems Methodology (SSM), with the purpose of characterizing the problematic situation and proposing a conceptual model for implementation. Following the protocol of the SSM steps, it was possible to identify several conditions associated with the lack of maintenance management, such as the absence of maintenance plan, building inspections, database, work order, among others. The use of SSM led to the development of a conceptual model and proposed improvement based on building maintenance management tools that could be implemented. To help managers make decisions, the final development of the research indicated the order of importance for the implementation of the tools, using the Analytic Hierarchy Process (AHP) technique, based on the criteria: benefits, opportunities, costs and risks (BOCR). The results indicated that the order of importance for the implementation of building maintenance management tools in the institution is firstly the Maintenance Plan, followed respectively by Inventory Management, Human Resource Management, Quality Management and finally the Computerized System.

4
  • MARCO TÚLIO DOMINGUES COSTA
  • INTEGER PROGRAMMING APPLICATION IN CARRIER VEHICLE ROUTING OPTIMIZATION

  • Advisor : EMERSON JOSE DE PAIVA
  • COMMITTEE MEMBERS :
  • EMERSON JOSE DE PAIVA
  • FÁTIMA MACHADO DE SOUZA LIMA
  • TARCISIO GONCALVES DE BRITO
  • Data: Dec 10, 2019


  • Show Abstract
  • The organizations evolutions and the intensification of business competition, also present in the field logistics fields, impose the need for organizations to perfect their processes. This work presents the improvement of the logistic process of a carrier by proposing a new variant for the vehicle routing problem, the Vehicles Routing Problem with Support Deposit and Duration Constraints (SD-DCVRP). This variant can be described as a VRP with two depots, one most important, from which all deliveries start, but which has the characteristic of being peripheral, and a second deposit that has a centralized location and acts as a support to the first. The purpose of the SD-DCVRP is minimize total travel time and reduce the number of vehicles used. For this variant, a generic mathematical model is proposed in order to solve this type of problem considering a small number of vertices. For this, the scenarios evaluated were simulated using the Monte Carlo method, the problem was solved by exact computational methods and presented satisfactory answers.

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