Papers by Flávio Luis de Mello
Texture management in view dependent application for large 3D terrain visualization
Spring Simulation Multiconference, Apr 14, 2008
This paper presents a method for view-dependent texture management into a large terrain 3D visual... more This paper presents a method for view-dependent texture management into a large terrain 3D visualization system. The proposed system can handle several collections of images, each one subdivided in tiles and stored in a database management system (DBMS). The main contribution of this work is a methodology for managing multi-resolution textures in multiple caching levels (database, main memory and graphics
Frontiers in Tropical Diseases, 2022
In Brazil, the tick-borne rickettsiosis known as Spotted Fever (SF) has been recorded from 59% of... more In Brazil, the tick-borne rickettsiosis known as Spotted Fever (SF) has been recorded from 59% of the Federative Units, however, the knowledge of the epidemiology and dynamics of human infection remains incipient in certain areas, complicating appropriate public health actions to inform the general population and control the disease. Here, we improved the interpretation of epidemiological information of SF cases recorded for an important endemic area. A descriptive epidemiological study was carried out based on records in the SINAN (Notifiable Diseases Information System) SF case databases. Data analysis was performed using Python programming language, Pandas library and Qgis map making. To evaluate the sociodemographic, clinical, assistance, laboratory and epidemiological characteristics, simple and relative nominal values of occurrences, means and standard deviations, and molecular analyzes were performed to identify the bioagent present in biological samples collected during each...
This paper analyzes the use of machine learning techniques for the identification of encryption a... more This paper analyzes the use of machine learning techniques for the identification of encryption algorithms, from ciphertexts only. The experiment involved corpora of plain texts in seven different languages; seven encryption algorithms, each one in ECB and CBC modes; and six data mining algorithms for classification. The plain text files were encrypted with each cryptographic algorithm under both cipher modes. After that, the ciphertexts were processed to produce metadata, which were then used by the classification algorithms. The overall experiment involved not only a high quantity of ciphertexts, but also time consuming procedures for metadata creation as well as for identification. Therefore, a high performance computer and customized memory management were employed. As expected, the results for ECB mode encryption algorithm identification were significantly high, and also reached full recognition. On the other hand, algorithm identification under CBC is supposed to be marginal, but successful identification was up to six times higher than the probabilistic bid.
Modo de acesso: World Wide Web Inclui bibliografia 1. Tecnologia 2. Automação 3. Engenharia I. Tí... more Modo de acesso: World Wide Web Inclui bibliografia 1. Tecnologia 2. Automação 3. Engenharia I. Título CDD-620 O conteúdo dos artigos e seus dados em sua forma correção e confiabilidade são de responsabilidade exclusiva dos seus respectivos autores.
Journal of Information Security and Cryptography (Enigma), 2021
Reliable network traffic classification is essential to management and security tasks. Therefore,... more Reliable network traffic classification is essential to management and security tasks. Therefore, it is beneficial to analyze and improve existing techniques. Some of the most traditional methodologies for traffic classification are based on port number and packet payload, each of which presents an increasing set of problems. Port number-based classification techniques suffer from the misuse of port numbers and tunneling. This is primarily due to their reliance on the proper use of IANA (Internet Assigned Numbers Authority) assigned numbers. On the other hand, packet payload-based classification has difficulty dealing with encrypted data and legal restrictions to accessing user data. Flow feature-based classification canovercome these challenges by creating profiles based on the traffic patterns of applications. Furthermore, machine learning techniques have shown to be a good match for traffic classification. Thus, the goal of this paper is to explore the combination of these fields...
Energies, 2021
This paper presents a big data analytics-based model developed for electric distribution utilitie... more This paper presents a big data analytics-based model developed for electric distribution utilities aiming to forecast the demand of service orders (SOs) on a spatio-temporal basis. Being fed by robust history and location data from a database provided by an energy utility that is using this innovative system, the algorithm automatically forecasts the number of SOs that will need to be executed in each location in several time steps (hourly, monthly and yearly basis). The forecasted emergency SOs demand, which is related to energy outages, are stochastically distributed, projecting the impacted consumers and its individual interruption indexes. This spatio-temporal forecasting is the main input for a web-based platform for optimal bases allocation, field team sizing and scheduling implemented in the eleven distribution utilities of Energisa group in Brazil.
Frontiers in Psychology, 2021
This study describes a method to assist the task of predicting the result of the decision-making ... more This study describes a method to assist the task of predicting the result of the decision-making process of an individual based on psychological and emotional aspects and using artificial intelligence (AI) techniques. This study presents indicators created for profile identification, which are organized in primary and circumstantial categories. These indicators are merged according to the ultimate purpose of profile identification, including the expected behavioral pattern for a person who performs a decision-making process. The person behavior hypothesis was successfully tested and can be approximated by an indicator such as mental functioning pattern, and the mental functioning pattern hypothesis can signal the most likely decisions of an individual. Four debtor decision variables were assessed in a debt negotiation process, in order to validate the method, which is applicable to other decision-making domains. The best signaling of the most likely decision of the debtor was seven ...
Boletim De Ciencias Geodesicas, 2008
To apply the linear model to interpolate attributes for 2D points, the attributes of three points... more To apply the linear model to interpolate attributes for 2D points, the attributes of three points ware weighted with their respective barycentric coordinates. However, the finite arithmetic effects at the computation returns barycentric coordinates contaminated with numerical residuals that, despite their irrelevant dimensions that face the representable objects, it may influence the system to make decisions involving values comparisons. In order to fix this problem, tolerance limits were established around the theorical value, and the processed values are attuned. This paper analyzes the influence from attributes interpolation numerical precision over a computational environment. The limits for residuals produced by computational barycentric coordinates calculus were defined. Those limits were chosen so that data imprecision did not exceed it original cartographical documents precision limits, according to the Padrao de Exatidao Cartografica (PEC), under the most rigid classificati...
This work aims to present a decision support system focused on a technical feasibility study thro... more This work aims to present a decision support system focused on a technical feasibility study through site survey procedure, making it possible to develop better cellular telecommunication business. The proposed architecture is based on the business model known as Mobile Virtual Network Operator (MVNO). The Full MVNO operational model is adopted in order to meet the requirements of the Brazilian National Telecommunication Agency (ANATEL). The developed methodology uses smartphones acting as probes for measuring mobile telephone systems. MVNO subscribers with specific profile may perform active or passive field measurements in real time, thus generating a consistent database which holds the mobile network behavior. The proposed decision support system solution can be used by telecommunication service operators, last mile service installation, system integrators, technological solutions consultants, and sales force team for telecommunication services.
Computational Intelligence Methods Applied to the Fraud Detection of Electric Energy Consumers
IEEE Latin America Transactions, 2019
Brazilian Energy Distributors need to pay special attention to electric energy loss due to non-te... more Brazilian Energy Distributors need to pay special attention to electric energy loss due to non-technical irregularities. Fraud and robbery represents a loss of revenue of billions of dollars every year. The energy utilities first approach to this problem was the creation of campaigns for prevention, raising awareness of the population and encouraging the denunciation of fraudsters. Unfortunately, this was not enough and proactive actions were needed. The current effective strategy is conducting technical inspections at consumers to whom there is some kind of evidence, based on customer data, consumption patterns, reader's notes, etc. This paper the application of neural network models, nnet and avNNet, on selecting a set of consuming units for which there is a high probability of frauds and irregularities. It also includes data enrichment to enhance the results of such neural networks. First, it presents a brief introduction about the problem, scope of this article and related w...
Journal of Information Security and Cryptography (Enigma), 2019
The concern of companies to keep sensitive data protected from improper access and information le... more The concern of companies to keep sensitive data protected from improper access and information leaking has grown a lot. The constant cases of industrial espionage and information leakage regarding companies are an evidence of the need to apply strict information security policies, improve data protection and allow an auditing track. With the evolution of technology, the usage of personal mobile devices increased in organizations (BYOD - Bring Your Own Device), which allows the employees to use their own mobile devices at work. This paper addresses the current challenges faced by IT companies and teams in protecting access to this kind of information, and what strategies are used to mitigate, to track leaks, and reduce the misuse of documents in the organization. Considering the scenario evaluated, a framework with good Information Security practices based on the ISO 27002:2005 and the practical controls of the Center of Internet Security (CIS) is proposed, associating good practices...
Parasites & Vectors, 2021
Background There are more than 300 species of capillariids that parasitize various vertebrate gro... more Background There are more than 300 species of capillariids that parasitize various vertebrate groups worldwide. Species identification is hindered because of the few taxonomically informative structures available, making the task laborious and genus definition controversial. Thus, its taxonomy is one of the most complex among Nematoda. Eggs are the parasitic structures most viewed in coprological analysis in both modern and ancient samples; consequently, their presence is indicative of positive diagnosis for infection. The structure of the egg could play a role in genera or species discrimination. Institutional biological collections are taxonomic repositories of specimens described and strictly identified by systematics specialists. Methods The present work aims to characterize eggs of capillariid species deposited in institutional helminth collections and to process the morphological, morphometric and ecological data using machine learning (ML) as a new approach for taxonomic iden...
JUCS - Journal of Universal Computer Science, 2020
Artificial Intelligence (AI) pervades industry, entertainment, transportation, finance, and healt... more Artificial Intelligence (AI) pervades industry, entertainment, transportation, finance, and health. It seems to be in a kind of golden age, but today AI is based on the strength of techniques that bear little relation to the thought mechanism. Contemporary techniques of machine learning, deep learning and case-based reasoning seem to be occupied with delivering functional and optimized solutions, leaving aside the core reasons of why such solutions work. This paper, in turn, proposes a theoretical study of perception, a key issue for knowledge acquisition and intelligence construction. Its main concern is the formal representation of a perceived phenomenon by a casual observer and its relationship with machine intelligence. This work is based on recently proposed geometric theory, and represents an approach that is able to describe the inuence of scope, development paradigms, matching process and ground truth on phenomenon perception. As a result, it enumerates the perception variab...
Journal of Information Security and Cryptography (Enigma), Jan 27, 2019
Internet of Things (IoT) accelerating growth exposes many unsecured issues related to the design ... more Internet of Things (IoT) accelerating growth exposes many unsecured issues related to the design and the usage of network integrated devices. This paper presents a fuzzy evaluation method, based on both IOT hardware/software developers' and users' knowledge, creating an novel model to aid correctness actions over security procedures, in order to increase the IOT safeness usage. This method combines both the developer's and user's perspectives, creating an integrated adaptive evaluation attached to the Information Technology security standards and best practices guidelines. The proposed evaluation method is divided by categories, each one composed of security control clauses and their corresponding action recommendation. The user perspective of such evaluation method was applied into a service company, and the developer perspective was defined by an IoT device manufacturer. The obtained results have shown that the evaluation method enhances both the manufacturer security awareness and the IOT users experience in the improvement of security IoT issues.
Journal of Information Security and Cryptography (Enigma), 2018
The accelerated growth of Internet of Things (IoT) exposes many unsecured issues related to desig... more The accelerated growth of Internet of Things (IoT) exposes many unsecured issues related to design and usage of devices leading to a new technological security paradigm. This paper presents an evaluation method and corrective actions to be carried out in order to make the usage of IoT devices safer. This method combines both the developer’s perspective and user’s perspective, thus differing from current guides. The proposed evaluation method is divided by categories, each one composed of security control clauses and their corresponding action recommendation. The user perspective of such evaluation method was applied into a service company, and the developer perspective into an IoT device manufacturer. These experiments produced useful perceptions on such view points. The evaluation provided an opportunity to enhance manufacturer security awareness and improve user experience with IoT devices.
Journal of Information Security and Cryptography (Enigma), 2015
This paper presents a Theory of Computation study based on recursive functions computability and ... more This paper presents a Theory of Computation study based on recursive functions computability and innovates by performing parallels to relevant themes of Cryptography. Hence, it is presented the Hennie's notion of "abstract family of algorithms" (AFA, for short) according to the authors' understanding, and also more judicious theorems demonstrations, many times completely different from those ones available in literature. The main issue is the Isomorphism Theorem which supports the Church-Turing Thesis and provides a connection between Cryptology and Linguistics.
Journal of Information Security and Cryptography (Enigma), 2016
This paper aims to study encrypted text files in order to identify their encoding algorithm. Plai... more This paper aims to study encrypted text files in order to identify their encoding algorithm. Plain texts were encoded with distinct cryptographic algorithms and then some metadata were extracted from these codifications. Afterward, the algorithm identification is obtained by using data mining techniques. Firstly, texts in Portuguese, English and Spanish were encrypted using DES, Blowfish, RSA, and RC4 algorithms. Secondly, the encrypted files were submitted to data mining techniques such as J48, FT, PART, Complement Naive Bayes, and Multilayer Perceptron classifiers. Charts were created using the confusion matrices generated in step two and it was possible to perceive that the percentage of identification for each of the algorithms is greater than a probabilistic bid. There are several scenarios where algorithm identification reaches almost 97, 23% of correctness.
Journal of Information Security and Cryptography (Enigma), 2020
It is becoming notorious several types of adversaries based on their threat model leverage vulner... more It is becoming notorious several types of adversaries based on their threat model leverage vulnerabilities to compromise a machine learning system. Therefore, it is important to provide robustness to machine learning algorithms and systems against these adversaries. However, there are only a few strong countermeasures, which can be used in all types of attack scenarios to design a robust artificial intelligence system. This paper is structured and comprehensive overview of the research on attacks to machine learning systems and it tries to call the attention from developers and software houses to the security issues concerning machine learning.
Anais do 14º Simpósio Brasileiro de Automação Inteligente, 2019
This work describes an environment for functional testing in credit card machines, ensuring great... more This work describes an environment for functional testing in credit card machines, ensuring greater quality on software developing on this kind of embedded system. These payment terminals, known as Point of Sale (POS), have some safety standards that limits tests performed only by software. Two of these limitations are: the data of card chips cannot be emulated by software, it is mandatory the presence of a physical card; and the card password insertion is only possible by physical interaction with terminal's keyboard. To overcome these limitations and allow perform functional testing fully automated, it was designed a robot capable of act physically with POS terminals for card insertion and removal, and for keyboard entry using actuators. This work describes the tools used for performing automated tests and the mechanical project of the robot prototype. Finally, it is presented the obtained results with examples of automated test cases in a payment application without the need of human interaction. Resumo: O presente trabalho descreve um ambiente robotizado para testes funcionais em máquinas de cartão de crédito, assegurando maior qualidade no desenvolvimento de software para esse tipo de sistema embarcado. Esses terminais de pagamento, denominados Point of Sale (POS), possuem especificações de segurança que impõem limitações a testes realizados somente por software. Duas dessas limitações são: os dados de um cartão de chip não podem ser emulados por software sendo necessária a presença de um cartão físico; e a inserção de senha do cartão também só possível via interação física com o teclado do terminal. Para permitir preencher as lacunas de um teste totalmente automatizado, foi desenvolvido um robô capaz interagir fisicamente com os teclados de terminais POS e realizar inserção e remoção de cartões utilizando atuadores, bem como outros tipos de interações de usuário com aplicações do terminal. Nesse trabalho são descritas as ferramentas para configuração do ambiente de testes e o projeto mecânico do protótipo do robô. Por fim, são apresentados os resultados obtidos com exemplos de cenários de teste automatizado em aplicação de pagamento sem necessidade de interação humana com o terminal.
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Papers by Flávio Luis de Mello