Pedro Paulo BalestrassiUniversidade Federal de Itajubá (UNIFEI) · Instituto de Engenharia de Produção e Gestão (IEPG)
Pedro Paulo Balestrassi
PhD
About
184
Publications
47,128
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Introduction
I am a researcher in the areas of Applied Statistics, Six Sigma and Neural Networks. As a full Professor at the Federal University of Itajubá/Braz I had sabbaticals at BarcelonaTECH (2017), The University of Tennessee at Knoxville (2010-2011) and The University of Texas at Austin (2005-2006). I am a Ph.D. in Industrial Engineering at the Federal University of Santa Catarina (2000) with an internship at Texas A&M University (USA). All my papers are available at https://pedro.unifei.edu.br/
Additional affiliations
March 1994 - present
Publications
Publications (184)
Dry turning reduces the environmental impact and costs associated with cutting fluids, but it challenges the optimization of tool life due to the generated heat. This study evaluated machine learning models to predict tool life (T) during the dry turning of AISI H13 steel by analyzing cutting speed (Vc), feed rate (f), and depth of cut (ap). Ninete...
There is a need for a methodology that allows the prosumer to implement a policy of choosing different compensation mechanisms. Thus, we propose the economic equivalence between net metering rolling credit (NM-RC) and net billing buyback (NB-BB) by defining a breakeven price (BP) for NB-BB that equals the Net Present Value (NPV) of these two option...
Electricity access and affordability are critical for sustainable development. There is a significant global population without access to electricity in the rural communities of developing countries. Rural grid investments are unattractive to investors due to low electricity demand and poverty of rural consumers. This paper assessed the financial c...
The study conducts a comparative assessment between the chatbots GPT-4 and Bard, focusing on their performance in statistical analysis. Through a statistical test of 20 questions, the research aims to identify which chatbot performs better in interpreting and analyzing information, both textual and graphical. Results indicate GPT-4's superior accur...
The COVID-19 pandemic has impacted not only the health system but also several other sectors of society. Urban mobility patterns have changed due to social distancing and isolation, which have impacted public transport around the world. This paper aims to analyze the effect of the COVID-19 pandemic on the number of passengers transported by public...
RESUMO Este estudo investigou o desempenho de seis ferramentas no processo de torneamento a seco do aço AISI H13. A análise de correlação identificou as variáveis T (Vida) e Kp (custo)como altamente correlacionadas. A análise de variância multivariada para dois fatores (MANOVA Two-Way) mostrou diferenças significativas entre as ferramentas, seus re...
O aço AISI H13 é um dos metais mais utilizados na manufatura. Um dos principais métodos de produção de peças a partir desse metal é o torneamento a seco, que exige um alto nível de controle do processo. Este estudo teve como objetivo analisar as características específicas do torneamento a seco do aço AISI H13 por meio de análises estatísticas mult...
Modelos de previsão auxiliam na tomada de decisão e podem ser aplicados em diversos campos do conhecimento, inclusive na previsão de consumo energético. O monitoramento da performance do modelo é uma das etapas de previsão e ferramentas como as cartas de controle podem ser utilizadas nesse momento. Nesse sentido, o objetivo desse trabalho é avaliar...
Portfolio analysis is widely used by financial investors to find portfolios producing efficient results under various economic conditions. Markowitz started the portfolio optimization approach through mean-variance, whose objective is to minimize risk and maximize the return. This study is called Markowitz Mean-Variance Theory (MVP). An optimal por...
O presente trabalho tem como foco a análise do ensino técnico à distância, com ênfase particular nos cursos técnicos profissionalizantes de Automação Industrial, Eletroeletrônica, Mecatrônica e Mecânica durante a crise da pandemia da Covid-19. Investigaremos as principais estratégias pedagógicas adotadas pelos docentes para superar os desafios impo...
Photovoltaic systems are largely involved in the process of decarbonization of the electricity production. Among the solutions of interest for deploying higher amounts of photovoltaic (PV) energy generation for reducing the electricity taken from the grid, the inclusion of local battery energy storage systems has been considered. Battery energy sto...
A microgrid is a group of interconnected loads and distributed energy resources that can fill the gap between the dependence on a bulk power grid and the transition to renewable energies. The islanded mode presents itself as the most interesting scenario, when local controllers should maintain the power quality standards based on several parameters...
Electric power systems have experienced the rapid insertion of distributed renewable generating sources and, as a result, are facing planning and operational challenges as new grid connections are made. The complexity of this management and the degree of uncertainty increase significantly and need to be better estimated. Considering the high volati...
Since 2012, prosumer compensation in Brazil has been based on net metering. However, a new law (Ordinary Law 14300/2022) was recently approved by the Brazilian Congress to decrease financial compensations for electricity injected into the grid. Studies on distributed generation system economic feasibility impacts in light of this new regulation are...
The Brazilian electric energy compensation system (EECS) states that 100% of the energy generated and inserted into the grid should be returned to prosumers as credits to their energy bill. Ongoing regulatory changes propose that compensation should only be provided for the energy cost (43%). From this perspective, with awareness of the complementa...
This study proposes a method that combines different machine learning and lean six sigma techniques to calibrate cluster analysis through linkage methods. The power quality indexes of substations in Brazil, which are of interest to regulatory agencies, are used. The method uses the random forest mixed with rotated factor analysis to filter, minimiz...
This paper presents a multi-objective optimization algorithm that combines Normal Boundary Intersection method with response surface models of equimax rotated factor scores in order to simultaneously optimize multiples sets of means and variances of manufacturing processes characteristics. The algorithm uses equimax factor rotation to separate mean...
In a world with growing inequality, conflicts, and a critical state of the environment, it is crucial to understand the principles that govern societal issues such as population distribution, poverty, and violence in modern cities. For the sake of developing novel solutions, a holistic analysis of the dynamics of social systems is of paramount impo...
The use of statistical tools and statistical thinking in decision making is fundamental to the practice of engineering, in most areas. The recently coined term, Statistical Engineering, has shown that an engineer, in its two main functions of (i) improving processes or products and (ii) developing new processes or products, depends on data analysis...
For some time, renewable solar energy generations using cellular photovoltaic panels have stood out among the options, especially in the segment of micro and small companies, where the return on investment is usually higher. In this context, when micro and small companies do not have the capital for the enterprises, several others, mainly small one...
Recovering, recycling and reusing are some processes whose popularity is intense nowadays due to the increasing concern about sustainability and environmental issues. These processes are composed by some input variables that can be adjusted to optimize related relevant responses. The present paper, focusing on multiobjective optimization, proposes...
The welding process in aluminum is a complex process that commonly presents several issues such as weld bead discontinuity, cracks, and lack of penetration. Thus, an accurate specification of the parameters in order to achieve optimal values for the investigated responses is aimed by the industry. The present paper proposes the application of a mul...
Abstract Paper aims This paper presents a comparative evaluation of different forecasting methods using two artificial neural networks (Multilayer Perceptron network and Radial Basis Functions Neural Network) and the Gaussian process regression. Originality Due to the current world scenario, solving economic problems has become extremely important....
During the multi-objective optimization process, numerous efficient solutions may be generated to form the Pareto frontier. Due to the complexity of formulating and solving mathematical problems, choosing the best point to be implemented becomes a non-trivial task. Thus, this paper introduces a weighting strategy named robust optimal point selectio...
In the light of Brazilian energy regulatory context, cluster strategies are required to classify groups of substations for voltage sag purposes. Tuning cluster algorithms is not a trivial task, due the fact that these methods are sensitive to small errors. Therefore, this study proposes a new methodology based on principal components analysis (PCA)...
In 2018, A Regulatory Impact Analysis (RIA) was launched to review the Brazil's prosumer remuneration scheme in Brazil. Six policy alternatives that can impose different financial risks on photovoltaic prosumers, including whether or not there are complementary incentives, are considered. Policy implications are based on an analysis of the financia...
The welding process in aluminum is not a simple task to carry out. Problems such as weld bead discontinuity, cracks, and lack of penetration commonly occur in this kind of process. Thus, it is extremely necessary to have an accurate specification of the parameters in order to achieve optimal values for the investigated responses. In view of this, t...
This paper proposes a new multiobjective optimization with elliptical constraints approach for nonlinear models implemented in a cladding process of ABNT 1020 carbon steel plate using austenitic ABNT 316L stainless steel cored wire. Stainless steel stands out among the cladding materials as it allows obtaining surfaces with determined desirable cha...
In recent years, renewable and sustainable energy sources have attracted the attention of various investors and stakeholders, such as energy sector agents and even consumers. It is perplexing to observe and anticipate the required levels of photovoltaic generation, which are inherent tasks for such rapid insertion into the electric grid. This distr...
With the growing demand for ISO certifications, the number of studies
analyzing the evolution of such certifications over time in the most diverse
contexts and countries has also increased. There are several forecasting methods,
used as a way to verify the behavior of certain variables in the future, given their
history. In this context, this study...
The design of the control system in an inverter‐based microgrid (μGs) is a challenging problem due to the large number of parameters involved. Different optimisation methods based on obtaining an approximated mathematical model of the μG can be found in the literature. In these approaches, the non‐linearities and uncertainties of the real system ar...
Paper aims: Propose a continuous decision support system, a Digital Twin, integrating two widely used techniques, Discrete Event Simulation and forecasting methods.
Originality: With the evolution of the industry, there is a growing need for increasingly agile and assertive decision support systems. Also, familiar tools and techniques tend to chan...
This study proposes a Real Options approach to investigate the economic feasibility of a wind power plant investment with the option of abandoning along the project lifetime cycle. This novel approach considers uncertainties representation with respect to electricity sales revenue in the spot market, and the uncertainty represented by the settlemen...
Abstract: This study proposes an approach to help the bidding processes of hiring wind-photovoltaic farms in long-term energy
auctions. The proposed approach aims to define an optimal solution to configure wind-photovoltaic farms based on mixture
design of experiments and the Lp method, as well as an efficiency metric designed to achieve diversific...
Recentemente, a Empresa de Pesquisa Energética (EPE) publicou uma série de estudos, ressaltando o potencial brasileiro para a expansão de usinas eólico-fotovoltaicas. Entretanto, a ausência de um arcabouço regulatório com diretrizes bem definidas para os investidores determinarem a configurações dos projetos, se trata de uma limitação que impede a...
Personalization algorithms play an essential role in the way search platforms fetch results to users. While there are many empirical studies about the effects of these algorithms on Web searches like Google and Bing, reports about personalization on social media searches are rare. This exploratory study aims to understand and quantify the limits of...
Continuous drive friction welding is a solid-state welding process that has been experimentally proven to be a fast and reliable method. This is a complex process; deformations in the viscosity of a material alter the friction between the surfaces of the pieces. All these dynamics cause changes in the vibration signals; the interpretation of these...
Methods for supporting the bidding processes of hybrid wind-photovoltaic (W-PV ) farms are scarce, especially when numerous goals are included in the optimization problem. Therefore, the primary objective of this study is to develop a novel model that can help bidding of W-PV farms considering a range of objectives that maximize the environmental a...
One of the challenges of energy regulatory-agencies is to guide the agents decision-making process towards maximization of the overall welfare of the electricity sector. However, this is not a simple task since it requires meeting expectations of many stakeholders, from investors to consumers. This paper proposes an optimization methodology aimed a...
We propose to control the mean vector by taking larger samples but inspecting fewer quality characteristics if we work with samples of size n to control bivariate processes, then 2n observations are usually collected, half are observations of X1 and the other half are observations of X2; alternatively, we might work with samples of size 2n if only...
One of the main goals in flux-cored arc welding processes is the optimization of bead geometry, in which multiple geometric characteristics of the welding bead are important; therefore, multi-objective optimization programming is often applied in this manufacturing process. However, several optimization problems that use stochastic programming do n...
The Information and Communication Technology (ICT) becomes a critical area to business success; organizations need to adopt additional measures to ensure the availability of their services. However, such services are often not planned, analyzed and monitored, which impacts the assurance quality to customers. The backup is the service addressed in t...
Recently, renewable energy projects, such as photovoltaic systems, have become interesting generation alternatives thanks to the incentive strategies developed by several countries. For the user of photovoltaic microgeneration, there is interest in the financial return of the investment, which is most often financed by public banks with a limited b...
DMAIC (define, measure, analyze, improve and control) is one of the most utilized methods for guiding practitioners in the decision-making process of quality improvement projects. Industrial processes commonly deal with multiple critical-to-quality (CTQ) characteristics. When these characteristics are correlated, multivariate statistical techniques...
Cluster analysis is a multivariate data mining technique that is widely used in several areas. It aims to group automatically the n elements of a database into k clusters, using only the information of the variables of each case. However, the accuracy of the final clusters depends on the clustering method used. In this paper, we present an evaluati...
The case study refers to a micro hydrographic basin that hosted a small hydroelectric power plant that may be reactivated. Hydrologic data for this basin has been obtained following its hydrologic study. Box-Jenkis method was used to identify the water inflow forecast tentative ARIMA models. The goal was to identify ARIMA stochastic models that pro...
Laser beam machining (LBM) is a promising manufacturing process that exhibits several desirable quality characteristics. Given a large number of objective functions, the level of complexity increases in an optimization problem. Therefore, this study presents a multivariate application of the normal boundary intersection (NBI) method to reduce dimen...
Process optimization normally involves the combination of mathematical and statistical techniques which can be approached by distinct ways. Despite the fact that different methods can be found in the literature, the response surface methodology raised as one of the most effective ways for performing process optimization, by combining design and ana...
An optimization problem of the AISI 52100 hard-steel turning process is examined. A new approach is presented in which not only the machine parameters (cutting speed, feed rate, and depth of cut) but also the stochastic industrial variables of setup time, insert changing time, batch size, machine and labor costs, tool holder price, tool holder life...
The concern with the disposal of waste generated by industry as well as by households is not recent. This work has sought to make a review on the production and disposal of the waste generated by electrical and electronic products, such as computers and mobile phones. Also, this review aimed to characterize the components of such waste and investig...
Response Surface Methodology is an effective framework for performing modelling and optimization of industrial
processes. The Central Composite Design is the most popular experimental design for response surface
analyses given its good statistical properties, such as decreasing prediction variance in the design center, where
it is expected to find...
This paper presents the modeling of tool life and surface roughness for machining AISI 52100 steel with a hardness of 50 HRC through Design of Experiments and Response Surface Methodology (RSM) with a view to enhance the quality and productivity. Knowing that the tool life and surface roughness are factors that influence the quality of the product,...
Organizations focus on determining optimal operating conditions to ensure quality; however, industrial processes exhibit a high degree of variability and the use of robust estimators is a suitable alternative to model experimental data. As a case study, the surface roughness (R a ) of an AISI 12L14 steel turning process is optimized to find a centr...
This paper proposed a new multi-objective approach to find the optimal set of weight's combination of forecasts that were jointly efficient with respect to various performance and precision metrics. For this, the residues’ series of each previously selected forecasts methods were calculated and, to combine them through of a weighted average, severa...
Microgrids can be understood as a complete electrical power system in all characteristics which are inherent to them but on a tiny scale. Although small scaled, they are endowed with high operational and constitutive sophistication enabling them to operate independently, sometimes connected to the distribution system and other times, appropriately,...
Hard turning optimization problems are usually approached using response surface methodology. By running designed experiments, researchers build analytical models to represent the outputs under interest. However, most studies focus on the expected values of the outputs, and only a few consider the variances of the models, even though there are seve...