Admilson de Ribamar Lima Ribeiro

Asymmetric Encryption in Wireless Sensor Networks

A Wireless Sensor Network (WSN) is composed of autonomous devices called sensor nodes that generally have low computational power, limited data transmission and power constraints. AWSN consists of sensor nodes that capturing information from an environment, processing data and transmitting them via radio signals. WSNs are increasingly present in our days and can be found in environmental area (climatic measurements, presence of smoke), in health area (measurement of vital signs, temperature), home automation (motion sensor and image sensor) and other areas. Generally, WSNs have no fixed structure, and in many cases there is no monitoring station of sensor nodes during the operational life of the network, so a WSNmust have mechanisms for self-configuration and adaptation in case of failure, inclusion or exclusion of a sensor node.

JOnline: proposta preliminar de um juiz online didático para o ensino de programação

A educacao a distancia tem ganhado significativa atencao tanto na academia quanto nas iniciativas governamentais. Neste contexto, cresce tambem a preocupacao com a avaliacao da qualidade dos diversos aspectos destes cursos mediados pelas tecnologias da informacao e comunicacao. Apesar de muitos trabalhos discutirem diversos aspectos da avaliacao em Ead, a literatura carece de relatos de experiencia que, especialmente, abordem os cursos tecnicos a distancia que possuem especificidades relevantes. Assim, este trabalho relata uma experiencia onde se avalia e adapta uma das propostas existentes na literatura de avaliacao mediada por foruns, ao contexto dos cursos tecnicos a distancia, constituindo-se esta adaptacao e sua discussao as principais contribuicoes do mesmo.Em Educacao a Distância mediada por meio de Ambientes Virtuais de Aprendizagem, foruns de discussao sao um instrumento importante e amplamente utilizado na articulacao de debates e discussoes entre os atores envolvidos no processo de ensino e aprendizagem. Com a ampla utilizacao dos foruns muitas mensagens sao trocadas e isso, por vezes, excede a capacidade de monitoramento por parte dos professores e tutores. O presente trabalho apresenta a concepcao de um classificador de mensagens de foruns que classifica as mensagens em positivas ou negativas, a fim de identificar mensagens que necessitam de maior atencao. Este trabalho aplica conceitos de mineracao de textos, com o algoritmo SVM obtendo taxas de acerto satisfatorias.Este artigo apresenta o framework Contagious, cujo proposito e estabelecer diretrizes que norteiem a construcao de redes sociais online orientadas a Difusao de Inovacoes. Compreendo-se o fenomeno das redes sociais online como consequencia natural do carater social do ser humano, vislumbrou-se esse meio tecnologico de comunicacao e interacao social como potencial ferramenta para a extensao de praticas educativas, com vistas a formacao do carater integral do cidadao. Para isso, foi adotada a teoria de Difusao de Inovacoes, propria das ciencias sociais. As contribuicoes deste trabalho, portanto, compreendem duas vertentes: a) o mapeamento de principios de uma teoria social na forma de recursos computacionais e; b) um enfoque orientado a educacao sobre as redes sociais online.A proposta do trabalho consiste em desenvolver um sistema para ser usado no celular como ferramenta de auxilio para alfabetizacao, utilizando-se de imagens e sons como forma de facilitar o aprendizado. Como metodo de desenvolvimento utiliza-se o processo P@PSEduc (Processo Agil para Software Educativo) e a ferramenta JME (Java Micro Edition).O crescente uso e difusao de tecnologias Web, a ubiquidade de ferramentas educacionais vem proporcionado verdadeiras revolucoes nos ambientes de ensino. Atualmente, sabe-se que nao mais se deve tratar alunos de forma homogenea, como se assim os fossem. Em face disso, este artigo apresenta um sistema adaptativo de apoio a aprendizagem colaborativa, cujo tema e a construcao e representacao do conhecimento por meio de mapas mentais multimidia. Tal sistema, baseia-se na Teoria da Carga Cognitiva, cuja preocupacao primaria e a facilidade com a qual as informacoes sao processadas pelos individuos.

A management architectural pattern for adaptation system in Internet of Things

Internet of Things (IoT) applications carry on at an environment that is mainly highly dynamic and real time nature. Due that environment, such applications should be able to reason autonomously and give self-adaptive decisions. To date, there has not been an adequate architecture to incorporate self-adaptive property in that type of environment. Thus, we design a management architectural pattern for adaptation system in Internet of Things based on modeling of control loops. The architectural pattern is presented considering problem/motivation, solution, consequences and examples. An example of application of pattern is showed through a self-protecting architecture for Internet of Things.

ERLab: a middleware for remote access electronic laboratories

The main difficulty in building online research laboratories is the use of computing resources and electronic instruments in multiple hardware and software platforms. Thus, this paper describes a service-oriented middleware using Web Services called ERLab (Electronic Remote Laboratory). The main goal of ERLab is to share data and scientific instruments, which operate and communicate over different protocols for different users on the Internet.

An Approach to the Performance and Efficiency Power Analysis on Embedded Devices Using Asterisk

Voice over IP (VoIP) communication will dominate the computing world for years to come. In order to perform VoIP communication, it is necessary to encode and decode the voice. This process consumes the main computational resources, as an example, it is possible to mention the processor and memory. The telecommunication industries provide equipment with high purchasing prices, which makes the access to this technology still very restricted. Embedded devices are purposely constructed for certain applications, they execute systems with high criticality complexity. Asterisk is a free software for voice over IP communication and its main function is to implement the functions of a telephone exchange. These technologies promise to reduce costs and maximize results. This work describes a performance analysis on three modern embedded devices (Raspberry Pi 3, Orange Pi Plus 2 and Banana Pi M3) using the Asterisk voice over IP communication system. The performance analysis consists of evaluating the jitter, delay and bandwidth, as well as the number of concurrent calls supported in each device with SIP and IAX2 protocols with CODEC’s G.711a, G.711u, Gsm, Speex, Ilbc, G.722 and in parallel, monitor the RAM memory consumption, processing and energy. The results show that the Raspberry Pi 3 and the Banana Pi M3 devices support in a satisfactory manner a high number of simultaneous calls with moderate memory, processing and energy consumption. However, the Orange Pi Plus 2 device showed high processing consumption.

A Comparative Analysis of Network Management Protocols in IoT Applications

The complexity and growth of new smart objects networks are generating a new demand for the maintenance of these devices, with the need to remotely monitor and control these devices without consuming significant resources. Analyzing the memory and electric power consumption of the protocols used in the management of these networks is a way to highlight the best protocol alternatives for this type of application. This study develops an experimental study, analyzing the behavior of SNMP, Zabbix and MQTT protocols, in terms of memory and electric power consumption, when it is used in an Internet of Things application, with a sensor device implemented on the ESP8266. The experiment is performed by monitoring devices in an environment with some Motes and a Zabbix server. The study analyzes the ROM and RAM memories occupied by the firmware code, in addition to the electric power consumption of each protocol. At the end, the study confirms that the three protocols analyzed are supported by the platform used. The research shows that the SNMP is the protocol that consumes the least amount of device memory, that there is no significant difference in the energy consumption between the protocols and that the MQTT protocol is suitable to be used in this environment and it also enables a significant reduction in energy consumption.

A Security Approach using SIP Protocol in Imbedded Systems.

Voice over IP communication will dominate the world. However, given the growing demand for voice and data communication to make any and all communication reliable and secure, several attacks occur frequently in communication networks, so this work is based on verifying security, analyzing risks, vulnerabilities, such as verifying the attacks and proposing a security measure for voice over IP communication on embedded

A Self-configuration Web-API for the Internet of Things

Due to the fast growth of the Internet of Things (IoT), many concepts of distributed systems need to be adapted to this new paradigm. Due to the large size of these networks, it is important that such systems present autonomic characteristics. In this context, this paper performs the implementation of an autonomic system emphasizing the self-configuration of devices, aided by cloud computing through a Web-API that was developed for this purpose. The initial results were obtained from tests performed on the Z1 device with the help of the ContikiOS, running inside the Cooja simulator. The results revealed that there is an overflow of the code developed for the tested devices, but after deep analysis, and more development, we can get a good level of energy consumption and it is possible to reach the self-configuration of devices on the IoT environment.