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In this paper, we propose the replication of scientific experiments, with the participation of the general public, as one of the possible strategies to confront science deniers. Using the social media of the Federal University of Lavras (UFLA), the project entitled : The Magic of Physics and the Universe, invited the public to reproduce the experiment carried out by the Greek Eratosthenes over 2,100 years ago, which he proved that the Earth is spherical. We present a report of this experience to suggest that it is possible for citizens to experience scientific knowledge and observe the phenomena in a simple way, in order to develop a critical interpretation of false information that circulates in society. This proposal distinctively geeks to deconstruct the denial of the Earth's curvature through direct and collective participation of citizens in Eratosthenes' experiment, which permit more reflection on how the scientific method used to study this subject works., Comment: This article is written in Portuguese

This paper analyzes the redistributive impacts of indirect taxation reforms in Brazil inspired by PEC 45/2019, particularly in the version that led to EC 132/2023. Comparisons are made between the current system and the simulated reforms, considering the distribution of the tax burden among families in different income classes, as well as the impact on poverty and inequality indicators. The simulations are conducted based on the combination of effective tax rates that apply to goods and services consumed by households, using nationally representative microdata from family budgets., Comment: in Portuguese language

Women and gender-diverse people represent an important constituency in the food value chain. Among all working women globally, about one in three works upstream in the food value chain. These women face increasing barriers to safety, recognition and advancement. Yet very little about their experiences has been documented. In the limited instances where the women who power global supply chains have been put into focus, most have concentrated on the experiences of women workers in the apparel sector., Through desktop research, one-on-one interviews with local organizations, case studies and workshops, this paper provides information and guidance on how investors, who are well-positioned to encourage companies to advance gender equity upstream in company supply chains, can help reshape this narrative and encourage companies to act.

This study aims to discuss the impacts of a low-cost airline on the air transport market and, especially, to present the most recent findings from specialized literature in the field. To this end, various works on this topic, published since 2015, were selected and analyzed. From this analysis, it was possible to categorize the main topics discussed in the papers into five groups: (i) the impacts of a low-cost airline on competing airlines; (ii) impacts on airports; (iii) general impacts on the demand for air transport; (iv) effects on passengers' choice process; and (v) general effects on a geographical region., Comment: This article is written in Portuguese

The conservation of tropical forests is a current subject of social and ecological relevance due to their crucial role in the global ecosystem. Unfortunately, millions of hectares are deforested and degraded each year. Therefore, government or private initiatives are needed for monitoring tropical forests. In this sense, this work proposes a novel framework, which uses of distribution estimation algorithm (UMDA) to select spectral bands from Landsat-8 that yield a better representation of deforestation areas to guide a semantic segmentation architecture called DeepLabv3+. In performed experiments, it was possible to find several compositions that reach balanced accuracy superior to 90% in segment classification tasks. Furthermore, the best composition (651) found by UMDA algorithm fed the DeepLabv3+ architecture and surpassed in efficiency and effectiveness all compositions compared in this work., Comment: in Portuguese language. Best Paper Award at the Workshop of Undergraduate Works (WUW), SIBGRAPI 2023

This paper presents a comparative analysis of three routing strategies in opportunistic quantum networks. Quantum communication networks face unique challenges, such as the fragility of qubits and the need to create and maintain pairs of entangled states for reliable transmission. In this context, efficient and reliable routing is crucial to maximize the fidelity of the established routes, minimize the creation of new entangled pairs, and reduce the need for route recalculation. The routing strategies are compared based on the fidelity of the chosen routes, the number of entangled pairs created, and the number of route recalculations. The results obtained provide valuable information for the design and optimization of opportunistic quantum networks, contributing to advances in the efficiency and reliability of quantum communications., Comment: XIII Confer\^encia Nacional em Comunica\c{c}\~oes, Redes e Seguran\c{c}a da Informa\c{c}\~ao, in Portuguese language

Training machine learning models for predicting stock market share prices is an active area of research since the automatization of trading such papers was available in real time. While most of the work in this field of research is done by training Neural networks based on past prices of stock shares, in this work, we use iFeel 2.0 platform to extract 19 sentiment features from posts obtained from microblog platform Twitter that mention the company Petrobras. Then, we used those features to train XBoot models to predict future stock prices for the referred company. Later, we simulated the trading of Petrobras' shares based on the model's outputs and determined the gain of R$88,82 (net) in a 250-day period when compared to a 100 random models' average performance., Comment: in Portuguese language, Presented at: 1o Semin\'ario de Ci\^encia de Dados do IFSP. Campinas: 2023

In this article, we present several apparent paradoxes of special relativity and their respective solutions. These paradoxes have appeared since the advent of relativity in 1905, and in fact they are never paradoxes. From a didactic point of view, paradoxes are an excellent learning tool. They lead the student to confront, and abandon, several central concepts of Galilean theory, such as simultaneity and rigidity of extended bodies. In particular, we review a new and simple solution to the twin paradox, recently found by one of the present authors [1]. It does not need to consider reference accelerators or light signals, which are the solutions presented in the literature., Comment: in Portuguese language, paper accepted for publication in Revista Brasileira do Ensino de F\'isica

Recent works have demonstrated how Linear Parameter Varying Model Predictive Control (LPV MPC) algorithms are able to control nonlinear systems with precision and reduced computational load. Specifically, these schemes achieve comparable performances to state-of-the-art nonlinear MPCs, while requiring the solution of only one quadratic programming problem (thus being real-time capable). In this tutorial paper, we provide a step-by-step overview of how to implement such LPV MPC algorithms, covering from modelling to stability aspects. For illustration purposes, we consider a realistic implementation for a gas-lift petroleoum extraction process, comparing the LPV approach with the becnhmark nonlinear MPC software CasADi., Comment: Main text in portuguese, submitted to the 2023 Simp\'osio Brasileiro de Automa\c{c}\~ao Inteligente (SBAI 2023)

Application services often support mobile and web applications with REST interfaces, implemented using a set of distributed components that interact with each other. This approach allows services to have high availability and performance at a lower cost than a monolithic system. However, the existence of multiple components makes the development process of these systems more complex and therefore susceptible to errors. In this paper, we present JepREST, a system that automates the use of Jepsen libraries to test the correctness of distributed applications that provide a REST interface. Based on a service interface specification, JepREST generates and executes a set of tests with multiple clients performing operations concurrently, subsequently verifying if the system behaviour is linearizable. The preliminary evaluation shows that JepREST simplifies the testing of REST applications., Comment: in Portuguese language

We present the second part of a series of papers proposing a novel teaching sequence for Particle Physics in high school. The topic of the present work is Nuclear Physics. The goal of the sequence is to approach the subject in a way as to stimulate scientific literacy, from a perspective involving Science, Technology, Society and Environment (STSE). We evaluate the potentialities and effectiveness of the material proposed here, allied to a dialogical approach by the teacher, by analyzing the presence of scientific literacy and engagement indicators during interventions applied to a public school in Esp\'irito Santo, Brazil., Comment: 31 figures, in portuguese

Currently, transport planning has changed its paradigm from projects oriented to guarantee service levels to projects oriented to guarantee accessibility to opportunities. In this context, a number of studies and tools aimed at calculating accessibility are being made available, however these tools depend on job location data that are not always easily accessible. Thus, this work proposes the creation of a database with the locations of formal jobs in Brazilian cities. The method uses the RAIS jobs database and the CNEFE street faces database to infer the location of jobs in urban regions from the zip code and the number of non-residential addresses on street faces. As a result, jobs can be located more accurately in large and medium-sized cities and approximately in single zip code cities. Finally, the databases are made available openly so that researchers and planning professionals can easily apply accessibility analyzes throughout the national territory., Comment: 9 pages, in Portuguese language, 3 figures, 1 table, Data presentation paper

The importance of implementing unitarity constraints in meson spectroscopy is very briefly outlined for Portuguese students of engineering sciences and therefore non-experts in the field. After explaining the profound differences between meson spectroscopy and atomic spectroscopy, attention is paid to the shortcomings of standard Breit-Wigner parametrisations in the case of broad and/or overlapping resonances. Finally, the manifestly unitary Resonance-Spectrum-Expansion model, which lies at the heart of a recent invited review paper by the present authors, is graphically presented, together with a simple yet typical application to the long-controversial $K_0^\star(700)$ resonance., Comment: in Portuguese. Invited paper for the first new edition (no. 504) of the students journal "T\'{e}cnica" published on 3 November 2021 by the "Associa\c{c}\~{a}o dos Estudantes do Instituto Superior T\'{e}cnico" of IST in Lisbon, Portugal. Article is in Portuguese language, with an English abstract; 4 pages, 5 figures. Link to published version: https://www.paperturn-view.com/?pid=MTk197448&p=25&v=1.1

The purpose of this paper (which, in many passages, I take the liberty of writing in the first person singular for bringing a personal experience) is to show how teachers of Physics and Mathematics in Basic Education can teach, through a simple and playful activity, the rules of signs that are related to basic arithmetic operations involving positive and negative numbers. How? By using a ruler, or any other object that can be interpreted as a number line, and a flat mirror. By the way, as the justification of why this method works is physical and mathematical, this paper provides a succinct review on the formation of images by flat and spherical mirrors since some teachers of Mathematics may (just as a possibility) not know how it happens. Lastly, given the interdisciplinary nature of this activity, some additional considerations are also presented regarding how these teachers can use it to instigate the students to observe how Physics and Mathematics, together, are part of everyday life for all of us., Comment: 35 pages, 16 figures (this paper was purposely/exceptionally written in portuguese)

Linguistic ambiguity continues to represent a significant challenge for natural language processing (NLP) systems, notwithstanding the advancements in architectures such as Transformers and BERT. Inspired by the recent success of instructional models like ChatGPT and Gemini (In 2023, the artificial intelligence was called Bard.), this study aims to analyze and discuss linguistic ambiguity within these models, focusing on three types prevalent in Brazilian Portuguese: semantic, syntactic, and lexical ambiguity. We create a corpus comprising 120 sentences, both ambiguous and unambiguous, for classification, explanation, and disambiguation. The models capability to generate ambiguous sentences was also explored by soliciting sets of sentences for each type of ambiguity. The results underwent qualitative analysis, drawing on recognized linguistic references, and quantitative assessment based on the accuracy of the responses obtained. It was evidenced that even the most sophisticated models, such as ChatGPT and Gemini, exhibit errors and deficiencies in their responses, with explanations often providing inconsistent. Furthermore, the accuracy peaked at 49.58 percent, indicating the need for descriptive studies for supervised learning., Comment: in Portuguese language, 16 p\'aginas, 5 p\'aginas de ap\^endice e 4 imagens

Introduction and Objective. Assuming the need to rethink Education and its function as an element of social transformation and generator of a profound ethical change and promoter of other ways of being on planet Earth, this study seeks to understand the possible dialogues between Earth Pedagogy and Astrobiology in the construction and proposition of continuing education processes for science teachers. Methodology. A mini-course was promoted aimed at teachers and an attempt was made to report the construction process of the training process and, using Content Analysis, to analyze the contributions pointed out by the participants to their training and teaching practice. Results and Conclusion. The dialogue between knowledge in the continuing education of teachers contributes with fundamental elements to teaching practice, covering cognitive, emotional, individual and collective aspects, as well as highlighting the role of the university in promoting initiatives that bring Education and Complexity together., Comment: This article is written in Portuguese

In the research on FANETs (Flying Ad-Hoc Networks) and distributed coordination of UAVs (Unmanned Aerial Vehicles), also known as drones, there are many studies that validate their proposals through simulations. Simulations are important, but beyond them, there is also a need for real-world tests to validate the proposals and enhance results. However, field experiments involving drones and FANETs are not trivial, and this work aims to share experiences and results obtained during the construction of a testbed actively used in comparing simulations and field tests., Comment: in Portuguese language

We propose a physical mechanism for fine-tuning the phase of a domain wall around the equilibrium directions involving the application of an external field and a spin polarized current in opposite directions. In this way, the position of the domain wall remains unchanged, but its phase can be slightly modified around the initial equilibrium positions, applying the external field/current smoothly. We point out a few applications to which this fine tuning may lead., Comment: Written in portuguese. Submited to Revista Brasileira de Ensino de Fisica on March 15 2024

Blockchain technology has emerged as a necessity for the decentralization of payment methods and transactions, but it has brought with it many properties of distributed systems that have made it a crucial technology for overcoming some of society's challenges, especially in the context of decentralizing services, transparency of information, availability, and security. Its architecture and communication methods, although possessing some complex nuances to understand, particularly for the lay audience in the field of distributed systems, protocols, and computer networks. In this article, we will explore some topics of distributed systems related to blockchain technology., Comment: in Portuguese language

The growing interaction between traditional knowledge and formal sciences emerges as a relevant field of research. In this perspective, the aim of this article is to investigate the intersections between Physics and traditional knowledge in the ceramics practices of Vila Cuera, in Bragan\c{c}a, state of Para. Using an ethnographic approach, complemented by qualitative analysis, we realize that ceramists use their sensitive intuition and, masterfully, apply thermodynamic principles in the production of handmade ceramics. The results highlight the value of Ethnophysics, underlining that, long before the formal structuring of science as we know it, traditional societies already practiced and understood natural phenomena in tune with contemporary physical principles. We conclude that there is an inherent link between Physics and traditional knowledge with regard to the traditional ceramics practice, grounded on empirical observations and ancestral wisdom, that dialogues with science in a complementary relationship. The study highlights the importance of valuing and recognizing the knowledge of traditional populations by highlighting the knowledge doings of cultures and institutionalized science., Comment: in Portuguese

Since the development of lasers, we have continuously sought to advance techniques and theory to obtain beams with a high degree of coherence, as natural light sources provide incoherent light. However, there are applications where it is advantageous to use partially coherent (PC) beams in a controlled manner, such as in propagation through turbulent media. To generate a PC beam in the laboratory or in simulations, specific theories and methods are required. In this article, we provide an introduction to PC beam theory, describing how to generate them through modal decompositions and a step-by-step guide for simulating and analyzing beam generation inspired by experiments. To illustrate the methods, we present Gaussian Schell-Model beams as an example., Comment: 12 pages, in Portuguese language, 11 figures

Society is changing, has always changed, and will keep changing. However, changes are becoming faster and what used to happen between generations, now happens in the same generation. Computing Science is one of the reasons for this speed and permeates, basically, every other knowledge area. This paper (written in Portugu\^es) describes, briefly, the worldwide initiatives to introduce Computing Science teaching in schools. As the paper's main conclusion, it is essential to introduce Computing Science and Computational Thinking for kids before they enter into a university., Comment: 9 pages, in Portuguese. Published as a chapter in the book "Desafios da Educa\c{c}\~ao T\'ecnico-Cient\'ifica no Ensino M\'edio". 1ed.Rio de Janeiro: Academia Brasileira de Ci\^encias, 2018

In this paper, we present the Quantum Information Software Developer Kit - Qiskit, for teaching quantum computing to undergraduate students, with basic knowledge of quantum mechanics postulates. We focus on presenting the construction of the programs on any common laptop or desktop computer and their execution on real quantum processors through the remote access to the quantum hardware available on the IBM Quantum Experience platform. The codes are made available throughout the text so that readers, even with little experience in scientific computing, can reproduce them and adopt the methods discussed in this paper to address their own quantum computing projects. The results presented are in agreement with theoretical predictions and show the effectiveness of the Qiskit package as a robust classroom working tool for the introduction of applied concepts of quantum computing and quantum information theory., Comment: This is a didactic text written in Portuguese by undergraduate physics students under the supervision of Professor Clebson Cruz. This paper summarizes the class notes, activities, and projects developed by students of the Applied Quantum Computing course at the Federal University of Western Bahia - Brazil

In this work we study the dynamics in an apocalypse where the individuals can temporarily become zombies, returning to the living state again or die. We describe this dynamics using a modified version of the epidemic SIS model. The zombies can die when in contact with a terminator, which is part of the living people. To define the possible interactions we use an Erd\"{o}s-R\`{e}nyi network and we calculate how the absorbing and active phase of the original SIS model is influenced by the average network degree. We also use the component and domain distribution of the network to understand how this influence occurs., Comment: 8 pages, in Portuguese, 10 figures, conference paper

In this study, we will address some topics related to the privatization of airports in the scientific literature, in an attempt to provide an answer to the following question: does the privatization of airports bring positive results? Firstly, we turn our attention to the motivations leading to privatization, considering the two main parties involved, the government and the private sector. After all, the success of such a decision will be relative to the reasons that justify it. In a second moment, we will consider the regulatory issue, whose influence on the airport's financial performance is consolidated in the literature. In the third part, we address the main documented results of privatization, with special attention to productive efficiency, whose improvement is the most popular motivation for privatization., Comment: This article is written in Portuguese

This work focuses on trying to understand how the construction of an airline's network is made. For this purpose, the case of Azul was studied, investigating which and how factors affect the decision of this airline to enter domestic routes, in addition to analyzing how the merger of Azul with the regional airline Trip affected the company's network planning. For this, an academic study was conducted using an econometric model to understand the airline's entry model. The results show that Azul's business model is based on connecting new destinations, not yet served by its competitors, to one of its hubs, and consistently avoiding routes or airports dominated by other airlines. Regarding the effects of the merger, the results suggest that Azul moved away from its original entry model, based on JetBlue, to a model more oriented towards regional aviation, entering shorter routes and regional airports., Comment: This article is written in Portuguese

In recent years, the topic of global warming and greenhouse gas emissions has been increasingly in the media. This theme has raised various flags, showing concern for the future and seeking alternatives for a more sustainable life over the years. When studying greenhouse gas emissions, one of the main emitters of such gases is the burning of fuels, in which transport vehicles that depend on gas and oil are included. In this respect, air transport through aircraft is one of the sources emitting such gases. Aiming to reduce gas emissions, one of the ways to do this is by reducing fuel consumption; for this, aircraft would have to be more efficient, or the offer and demand for flights would be reduced. However, what if aircraft fuel consumption were taxed? What would be the effects of this on air transport? Could this be one of the alternatives to reduce emissions? To understand this relationship between taxation and a possible reduction in fuel consumption, a study was developed by the Aeronautics Institute of Technology (ITA), using an econometric model to understand how demand would be affected by changes in airfares. In addition, a simulation of possible environmental taxes on the values of air tickets was carried out to analyze the demand response and to get an idea if this taxation would really solve the emission problems., Comment: This article is written in Portuguese

The exploration of existing commercial opportunities has been increasing the share of commercial (non-aeronautical) revenues in the total revenues of airports worldwide. These revenues, also called commercial, non-aeronautical, or non-tariff revenues, come from rentals, duty-free shops, food and beverage sales, parking, advertising, etc. In other words, everything that is not the main business of the airport. Consequently, the dependence on commercial revenues has also become increasingly important, and airport managers are interested in understanding how to improve their financial results with this new revenue source, as it not only improves financial outcomes but also optimizes passengers' time and money consumption options at airports. Therefore, this chapter seeks to discuss the main determinants of commercial revenues at national airports, analyzing the possible impacts of the behavior of passengers from low-cost carriers (LCC) on these revenues, combined with other determining factors., Comment: This article is written in Portuguese

This study addresses the growing standardization of airline fleets, highlighting that frequent passengers are more likely to fly on the same aircraft model more often. The objective is to analyze the fleet management of airlines and the impact of a reduced variety of models on company operations. The benefits of standardization, such as operational efficiency, and the risks, such as vulnerability to specific model failures, are discussed. The work reviews international scientific literature on the subject, identifying consensus and disagreements that suggest areas for future research. It also includes a study on the Brazilian market, examining how standardization affects operational costs and profitability in terms of model, family, and aircraft manufacturer. Furthermore, the relationship between fleet standardization and the business model of the companies is investigated, concluding that the advantages of standardization are not exclusive to low-cost companies but can also be leveraged by other airlines., Comment: This article is written in Portuguese

This study explores the approaches used by airlines in setting flight times. It highlights the need to balance operational and strategic factors, such as optimizing the use of resources - including aircraft, crew, and fuel - and managing the risks related to delays and congestion. The work details a national analysis focused on domestic flights, investigating the factors that influence companies to adjust scheduled flight times and the impact of this practice on punctuality. The results indicate that decisions about flight time are influenced by both operational and strategic aspects, being affected by competition and the sector's policies on punctuality and slot allocation. Furthermore, it was found that adding extra time is an effective strategy for reducing delays, although it may conceal system deficiencies., Comment: This article is written in Portuguese

This work presents an analysis of recent literature examining factors that influence flight times in Brazil, with special attention to the impact of new technology implementations, specifically Performance-Based Navigation (PBN). PBN procedures began to be implemented in Brazilian airspace in 2009 and represent a new concept of air navigation, using satellites to create 3D flight routes that are shorter and more precise, potentially reducing the distances flown and consequently flight times and delays. Flight times depend on various factors, such as the size and complexity of the origin and destination airports, weather conditions, aircraft models, and how full the flights are. Therefore, to assess the impact of the new procedures, the variation in this set of factors must be taken into account. The results found in the literature suggest that Performance-Based Navigation had a positive impact, reducing flight times by about 1-2%, representing a saving of tens of thousands of flight hours from the beginning of implementations in 2009 until the end of 2018., Comment: This article is written in Portuguese

Flight delays are a reality in the modern air industry worldwide. However, studies in the literature have investigated the competitive determinants of delays arising from factors originating at the airport and along the route separately. This work aims to present a national study that used a unifying approach from the literature, considering the local and global effects of competition on delays. The analysis took into account a phenomenon known as the "internalization of externalities" of airport congestion. Furthermore, it discusses the relationship between quality and competition on the route and the impacts of the entry of a low-cost carrier (LCC) on the delays of incumbent airlines in the Brazilian air market. The literature suggests that there is evidence of congestion internalization at Brazilian airports, in parallel with competition for quality at the route level. Additionally, the potential competition caused by the presence of the LCC leads to a global effect that suggests the existence of impacts other than prices on routes where it has not entered., Comment: This article is written in Portuguese

This study discusses the literature on the convergence of business models of airlines in Brazilian air transport, focusing on the formation of flight networks. Initially, it analyzes the determinants of the network formation patterns of the "fundamental" business models (archetypes) of airlines in the first years after the sector's deregulation. Then, it discusses how the business models of Brazilian companies resemble these patterns. The literature highlights convergences between the network formation strategies of full-service companies in relation to older low-cost companies, in addition to business model redirections after mergers and acquisitions., Comment: This article is written in Portuguese

This book, written in Portuguese, presents a comprehensive analysis of the air transport industry in Brazil, highlighting its vital importance to the country's economy. It explores the sector's complexity, from economic characteristics to interaction with the national aeronautical industry, through the specialization of the workforce and market demand analysis. The book delves into the economic regulation of air transport, tracing the evolution from periods of strict regulation to phases of liberalization and deregulation, and examines market dynamics, focusing on concentration and competitiveness. It also analyzes demand and supply through case studies, investigating everything from tourists traveling within Brazil to the coverage of the national territory and the prices of air tickets. Finally, the book proposes principles for the regulation and public policies of the air sector, emphasizing the priority of the passenger, the business environment, access to air transport, and economic efficiency, culminating in the advocacy for a free market, but with protection for competition and the consumer., Comment: Pezco Editora & Desenvolvimento - 1st Edition, 2009. In Portuguese

The intention of this article is to propose the use of artificial intelligence to detect through analysis by UFO ontology the emergence of verbal and physical aggression related to psychosocial deficiencies and their provoking agents, in an attempt to prevent catastrophic consequences within school environments., Comment: in Portuguese language. Minha vez de falar sobre a realidade

This systematic review focuses on analyzing the use of machine learning techniques for identifying and quantifying analytes in various electrochemical applications, presenting the available applications in the literature. Machine learning is a tool that can facilitate the analysis and enhance the understanding of processes involving various analytes. In electrochemical biosensors, it increases the precision of medical diagnostics, improving the identification of biomarkers and pathogens with high reliability. It can be effectively used for the classification of complex chemical products; in environmental monitoring, using low-cost sensors; in portable devices and wearable systems; among others. Currently, the analysis of some analytes is still performed manually, requiring the expertise of a specialist in the field and thus hindering the generalization of results. In light of the advancements in artificial intelligence today, this work proposes to carry out a systematic review of the literature on the applications of artificial intelligence techniques. A set of articles has been identified that address electrochemical problems using machine learning techniques, more specifically, supervised learning., Comment: in Portuguese language

This study presents the development of two graphical interfaces using Matlab's graphical user interface tool, GUIDE, to model the steady-state and dynamic responses of Erbium (Er$^{3+}$)-doped fiber amplifiers. The primary focus is on their application for educational purposes, employing two distinct models. The steady-state model aims to evaluate the influence of various intrinsic parameters of Er$^{3+}$-doped fibers, such as length, overlap factor between the dopant profile and the optical signal, dopant density, and excited state average lifetime, along with the impact of optical signals on the amplifiers' performance. On the other hand, the dynamic model interface facilitates the examination of the channels add/drop impact in an optical network. This dual-interface approach provides a comprehensive understanding of the Erbium-doped fiber amplifiers, making them valuable tools for educational exploration and analysis., Comment: 6 pages, 8 figures. Document in Portuguese

Studies on Quantum Computing have been developed since the 1980s, motivating researches on quantum algorithms better than any classical algorithm possible. An example of such algorithms is Grover's algorithm, capable of finding $k$ (marked) elements in an unordered database with $N$ elements using $O(\sqrt{N/k})$ steps. Grover's algorithm can be interpreted as a quantum walk in a complete graph (with loops) containing $N$ vertices from which $k$ are marked. This interpretation motivated search algorithms in other graphs -- complete bipartite graph, grid, and hypercube. Using Grover's algorithm's linear operator, the quantum counting algorithm estimates the value of $k$ with an error of $O(\sqrt{k})$ using $O(\sqrt{N})$ steps. This work tackles the problem of using the quantum counting algorithm for estimating the value $k$ of marked elements in other graphs; more specifically, the complete bipartite graph. It is concluded that for a particular case, running the proposed algorithm at most $t$ times wields an estimation of $k$ with an error of $O(\sqrt{k})$ using $O(t\sqrt{N})$ steps and success probability of at least $(1 - 2^{-t})8/\pi^2$., Comment: Master Thesis in Portuguese

In this paper we present modern portfolio theory using basic concepts of linear algebra, differential calculus, statistics and optimization. This theory allows us to measure the return and risk of the investment portfolio, helping to make decisions in the financial market. As an application, we will present a simple investment strategy that aims to minimize the risk of investing in two assets, Comment: 31 pages, in Portuguese language, 13 figures

This paper presents our efforts to build a robust ASR model for the shared task Automatic Speech Recognition for spontaneous and prepared speech & Speech Emotion Recognition in Portuguese (SE&R 2022). The goal of the challenge is to advance the ASR research for the Portuguese language, considering prepared and spontaneous speech in different dialects. Our method consist on fine-tuning an ASR model in a domain-specific approach, applying gain normalization and selective noise insertion. The proposed method improved over the strong baseline provided on the test set in 3 of the 4 tracks available, Comment: Proceedings of the First Workshop on Automatic Speech Recognition for Spontaneous and Prepared Speech & Speech Emotion Recognition in Portuguese (SE&R 2022), co-located with PROPOR 2022

In this paper we describe one of the most promising platforms for the construction of a universal quantum computer, which consists of a chain of $N$ ions trapped in a harmonic potential, whose internal states work out as qubits, and are coupled to collective vibrational modes of the chain. From such coupling, it is possible to build interactions between different ions of the chain, that is, qubit-qubit interactions that, together with individual operations on the ions, allow building a quantum computer as first proposed by Cirac and Zoller in the 1990s [Phys. Rev. Lett. 74, 4091 (1995)]. Here we discuss from the physics involved in trapping ions in electromagnetic potentials to the Hamiltonian engineering needed to generate a universal set of logic gates, fundamental for the execution of more complex quantum algorithms. Finally, we present the current state of the art of quantum computing in trapped ion systems, highlighting recent advances made by companies and government projects that use such architecture, such as IonQ and AQTION., Comment: 18 pages, in Portuguese language, 8 figures

Advances in image processing and analysis as well as machine learning techniques have contributed to the use of biometric recognition systems in daily people tasks. These tasks range from simple access to mobile devices to tagging friends in photos shared on social networks and complex financial operations on self-service devices for banking transactions. In China, the use of these systems goes beyond personal use becoming a country's government policy with the objective of monitoring the behavior of its population. On July 05th 2021, the Brazilian government announced acquisition of a biometric recognition system to be used nationwide. In the opposite direction to China, Europe and some American cities have already started the discussion about the legality of using biometric systems in public places, even banning this practice in their territory. In order to open a deeper discussion about the risks and legality of using these systems, this work exposes the vulnerabilities of biometric recognition systems, focusing its efforts on the face modality. Furthermore, it shows how it is possible to fool a biometric system through a well-known presentation attack approach in the literature called morphing. Finally, a list of ten concerns was created to start the discussion about the security of citizen data and data privacy law in the Age of Artificial Intelligence (AI)., Comment: 8 pages in Portuguese and 5 figures, Top 3 among the best papers at the ENIAC 2022

Only 5% of what makes up the Universe is well understood, and it consists of baryonic matter and radiation. Dark matter and energy correspond to the remaining 95% of the Universe, and their origin and evolution have not yet been satisfactorily explained. Dark matter, supposedly present in the galaxies' halo region, appears to be the mechanism that causes the unusual behavior of the stars' tangential velocity, which is higher than that predicted by the interaction with visible matter. With the solutions of the equations of motion for spacetime generated by a spinning cosmic string with an internal structure in Brans-Dicke gravitation, the present work aimed to evaluate whether this type of string can play the role currently defined as that of dark matter, which is to originate the typical rotational curves of galaxies, responsible for maintaining the tangential velocities of the stars that form these galaxies, whose behavior cannot be justified solely by the observed baryonic matter. For this, the model was used to obtain the velocities of the stars of 4 Sc-type galaxies, to be compared with their respective experimentally observed values., Comment: 11 pages, 2 figures, text in Portuguese, work presented at the 23a. Mostra de Ensino, Pesquisa e Extens\~ao, IFRS, C\^ampus Porto Alegre, 2023

In this work, we discuss the determination of the distance to the Large Magellanic Cloud (LMC) using the Leavitt Law, utilizing the public catalog of Classical Cepheid Variable stars from the observational project OGLE-IV (The Optical Gravitational Lensing Experiment Collection of Variable Stars), consisting of 4709 stars in the Large Magellanic Cloud. To determine the pulsation period of Cepheid Variable stars, we employ the computational algorithm \textit{Lomb-Scargle periodogram} modified for our data. Additionally, with the calculation of the period, we can derive a period-luminosity relation for Cepheid Variables in the Large Magellanic Cloud and, using an independent calibration distance, deduce their distance moduli. We also discuss some general theoretical concepts of the physical mechanism behind the oscillation of variable stars., Comment: in Portuguese language

The thought-provoking analogy between AI and electricity, made by computer scientist and entrepreneur Andrew Ng, summarizes the deep transformation that recent advances in Artificial Intelligence (AI) have triggered in the world. This chapter presents an overview of the ever-evolving landscape of AI, written in Portuguese. With no intent to exhaust the subject, we explore the AI applications that are redefining sectors of the economy, impacting society and humanity. We analyze the risks that may come along with rapid technological progress and future trends in AI, an area that is on the path to becoming a general-purpose technology, just like electricity, which revolutionized society in the 19th and 20th centuries. A provocativa compara\c{c}\~ao entre IA e eletricidade, feita pelo cientista da computa\c{c}\~ao e empreendedor Andrew Ng, resume a profunda transforma\c{c}\~ao que os recentes avan\c{c}os em Intelig\^encia Artificial (IA) t\^em desencadeado no mundo. Este cap\'itulo apresenta uma vis\~ao geral pela paisagem em constante evolu\c{c}\~ao da IA. Sem pretens\~oes de exaurir o assunto, exploramos as aplica\c{c}\~oes que est\~ao redefinindo setores da economia, impactando a sociedade e a humanidade. Analisamos os riscos que acompanham o r\'apido progresso tecnol\'ogico e as tend\^encias futuras da IA, \'area que trilha o caminho para se tornar uma tecnologia de prop\'osito geral, assim como a eletricidade, que revolucionou a sociedade dos s\'eculos XIX e XX., Comment: In Portuguese

We study characteristic classes of hypersurfaces in the complex projective space, with emphasis on secants to rational normal curves. For $Sec_k C\subset \mathbb{P}^{n}$, the secant of $k$ points to a rational normal curve $C\subset \mathbb{P}^n$, we compute the Hilbert series and the topological Euler characteristic. For $n=2r$ and $k=r$, the case when $Sec_r C\subset \mathbb{P}^{2r}$ is a hypersurface, we show that the dual $(Sec_r C)^*$ is isomorphic to the Veronese variety $\nu_2(\mathbb{P}^r)$, from which we obtain, for $Sec_r C$, formulas for the Mather class, the generic Euclidean distance degree and its polar degrees. Furthermore, we present an explicit formula for the topological degree of the gradient map $\phi_r \colon \mathbb{P}^{2r} \dashrightarrow \mathbb{P}^{2r} $ associated with $Sec_r C$, and as a consequence we obtain an affirmative answer for a conjecture by M. Mostafazadehfard and A. Simis: for $r \geq 2$, the hypersurface $Sec_r C\subset \mathbb{P}^{2r}$ is not homaloidal. From computations in particular cases we are led to a conjecture, namely, explicit formulas for the projective degrees of the gradient map $\phi_r$ and the Schwartz-MacPherson class $c_{SM}(Sec_r C)\in A_* \mathbb{P}^{2r}$, for all $r$. We conclude by presenting evidence that indicates the validity of our conjecture. Keywords: Characteristic classes. Gradient maps. Secants to rational normal curves., Comment: Ph.D. Thesis, final version, in Portuguese

The first edition of the event As Astrocientistas: the Brazilian Meeting of Women and Girls in Astrophysics, Cosmology, and Gravitation, happened in February 2021. It gathered great names of Brazilian science to pay homage to Brazilian female researchers and other female physicists with close ties to our community. This paper presents our motivation to organize this event, the challenges we faced, and exposes the learning experience we gained from doing so. We will talk about the relevance of this event as we perceive it., Comment: 14 pages, in Portuguese, 8 figures, version accepted for publication in Cadernos de Astronomia

In this paper, the expression of the relativistic Maxwell-J\"uttner velocity distribution was deduced in a detailed and didactic way. This distribution was compared with the well-known Maxwell-Boltzmann distribution, which does not take into account relativistic effects. Applications and comparisons between the two distributions were carried out in three situations: i) protons at solar surface temperature, ii) electrons at Lawson's criterion temperature, and iii) protons at quasar temperatures. It was found that the value of the ratio between the rest mass of the particle considered and the temperature of the system determines the need to consider or not a relativistic treatment for the velocity distribution function of the system., Comment: in Portuguese

Pressure ulcers have high prevalence in ICU patients but are preventable if identified in initial stages. In practice, the Braden scale is used to classify high-risk patients. This paper investigates the use of machine learning in electronic health records data for this task, by using data available in MIMIC-III v1.4. Two main contributions are made: a new approach for evaluating models that considers all predictions made during a stay, and a new training method for the machine learning models. The results show a superior performance in comparison to the state of the art; moreover, all models surpass the Braden scale in every operating point in the precision-recall curve. -- -- Les\~oes por press\~ao possuem alta preval\^encia em pacientes de UTI e s\~ao preven\'iveis ao serem identificadas em est\'agios iniciais. Na pr\'atica utiliza-se a escala de Braden para classifica\c{c}\~ao de pacientes em risco. Este artigo investiga o uso de aprendizado de m\'aquina em dados de registros eletr\^onicos para este fim, a partir da base de dados MIMIC-III v1.4. S\~ao feitas duas contribui\c{c}\~oes principais: uma nova abordagem para a avalia\c{c}\~ao dos modelos e da escala de Braden levando em conta todas as predi\c{c}\~oes feitas ao longo das interna\c{c}\~oes, e um novo m\'etodo de treinamento para os modelos de aprendizado de m\'aquina. Os resultados obtidos superam o estado da arte e verifica-se que os modelos superam significativamente a escala de Braden em todos os pontos de opera\c{c}\~ao da curva de precis\~ao por sensibilidade., Comment: 3 pages, 1 figure, in Portuguese, accepted at XVIII Congresso Brasileiro de Inform\'atica em Sa\'ude (CBIS 2021)