Navegando por Autor "Nóbrega, Obionor de Oliveira"

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Avaliação do consumo energético de smartphones em um sistema Smart Attendance
(2019) Cabral, Jefferson de Carvalho; Nóbrega, Obionor de Oliveira; Lins, Fernando Antonio Aires; http://lattes.cnpq.br/2475965771605110; http://lattes.cnpq.br/8576087238071129; http://lattes.cnpq.br/1111059195459577
Currently, the Internet of Things paradigm is being seen as the protagonist of the technological revolution in which the computer age lives. In this paradigm, the objects present in our daily lives will be connected to us and other objects. One of the major concerns in the (IoT - Internet of Things) universe is energy efficiency. Assuming that all objects can be connected to numerous networks simultaneously transmitting and receiving data, the wireless technologies must be able to act efficiently in the traffic of the information between the nodes without compromising the life of the batteries of those devices. In the educational context, these technologies aim at the developmentof intelligent classrooms as well as the creation of static applications that have thefunction of automating some manual activities carried out by teachers and students.One of these static applications is known as Smart Attendance, which aims to automate and solve the problem of the loss of 10% of class time for taking attendance by using technologies that promise a low power consumption. Although some solutions automate class attendance, the waste of 10% of class time still persists. This has commonly occurred due to some factors such as lack of visibility of the problem and inadequate use of the technology. Considering the last factor, this work aims to evaluate the energyconsumption of smartphones by taking roll in Smart Attendance systems using Bluetoothand Bluetooh Low Energy (BLE) technologies. Through the literature review, it was possible to analyze the work in the educational environment and to understand theIoT’s performance in this context, to understand the operation of the BLE protocol andto compare it with Bluetooth, to explore the work related to the automation of class attendance and to define a specification of the system data traffic, its message flowsand its operation. In order to evaluate the system, it was considered the simulation technique, which was chosen based on the main criteria used to select the systems performance evaluation techniques. Then, we used the OMNet ++ simulator with theINET framework to create a Mobile Ad Hoc Network (MANET) configured with Bluetooth and BLE characteristics, where the nodes of this network were the student and teacher smartphones. The results of this research point out that there are no quantitative differences between the Bluetooth and BLE technologies when compared within the metrics package error rate and signal-to-noise ratio. However, it proves the efficiency of the BLE over Bluetooth considering the energy consumption metric which makesBLE the most rational choice, among those evaluated, for the implementation of a Smart Attendance.
Development of machine learning models for the prediction of dissolved oxygen in aquaculture 4.0
(2021-02-24) Freitas, Fábio Alves de; Nóbrega, Obionor de Oliveira; Lins, Fernando Antonio Aires; http://lattes.cnpq.br/2475965771605110; http://lattes.cnpq.br/8576087238071129; http://lattes.cnpq.br/5725435192607619
The world faces the problem of feeding a growing population, which will reach more than 9 billion people by 2050. Thus, there is a need to develop activities that promote food production, within the dimensions of sustainability (social, technicaleconomic, and environmental). In this context, IoT systems focused on aquaculture 4.0 stand out, which allows the cultivation of high productions per unit of volume, with low environmental impact. However, these systems need to be extremely controlled, requiring sensors to perform realtime readings of water metrics, with emphasis on the dissolved oxygen (DO) sensor, which plays an essential role in determining the quality and quantity of available habitat for the organisms present in the system. Even with this importance, this sensor is often not used, due to its high associated cost. As an alternative solution to this problem, machine learning models have been proposed to predict DO, using temperature and pH readings as inputs. Experiments were carried out comparing different data scaling techniques and the prediction performance in different seasons of the year and regression metrics were used to evaluate the implemented models. The results showed that the proposed LSTM model is capable of making OD predictions and being applied in IoT and aquaculture 4.0 systems.
Security evaluation of operating systems considering compliance policies
(2021-03-01) Teixeira, Vanessa Bandeira Lins; Lins, Fernando Antonio Aires; Nóbrega, Obionor de Oliveira; http://lattes.cnpq.br/8576087238071129; http://lattes.cnpq.br/2475965771605110; http://lattes.cnpq.br/9351392044969981
Currently, to search, mitigate and solve security vulnerabilities is considered a relevant and complex task. New software are being developed everyday, and each one of them may bring its own vulnerabilities. In addition, the configurations of these applications can also increase these vulnerabilities. In this context, there is a lack of securityoriented configurations in a significant part of the current operating systems. These assets, which are usually not properly configured considering security requirements, become easy targets for a considered number of security attacks. The application of compliance policies in an operating system helps to preserve the environment from malicious exploitation. The main objective of this work is to evaluate the use of compliance policies to assess and improve the security level of operating systems. To achieve this, a methodology is proposed and described. This methodology is also applied to a case study with server operating systems. For this purpose, faults in the factory configuration of the operating systems were considered, which were identified using the Center for Internet Security (CIS) compliance policies. Thus, it became possible to evaluate the system security level and to classify the main recommendations for prioritizing the corrections that users can follow. Such recommendations aim to reduce the attacks surface on systems and increase the security level by mitigating the vulnerabilities to which the systems are exposed.
Sistema IoT de Monitoramento do Nível da Água de Rios para Cidades Inteligentes
(2021-02-23) Ramos, João Luiz da Silva; Nóbrega, Obionor de Oliveira; http://lattes.cnpq.br/8576087238071129; http://lattes.cnpq.br/3994213714014169
Currently, heavy rains are the main causes of natural disasters in Brazil, causing rivers to overflow and disturbances for the community affected by this problem. Therefore, the prototype of a low-cost device was developed, whose main objective is to monitor and transmit the data obtained (volume of the water level of the rivers). Considering the transmission and analysis of data, the device is enabled in the concept of Smart Cities and Internet of Things, as it uses information technology to collect, analyze and transmit data. For the construction of the prototype, an Arduino microcontroller board and some other electronic components were used. The source code of the device was developed through Arduino IDE, a code compiler, based on the C / C ++ programming language, where the data received by the hardware will be interpreted and analyzed. An accuracy test was applied to identify and relate the values obtained by the device, where the results were satisfactory, considering that the distance data captured by the device were accurate, compared to the actual physical quantity. A simulation was carried out in a cylindrical container (where such a scenario can be made a relationship with a river), where the results reached the expected goals: using the developed code, calculate the distance between the water level and the device, interpret the calculated value and turn on the LED related to the water level situation (red LED for high level, yellow LED for medium level or green LED for low level). Given this result, it is possible to validate the functionality of the developed code and the built hardware.