Search results

O estudo e implementação de redes de sensores sem fios é um campo emergente da eletrônica que está muito interligado com a internet das coisas. Juntas essas duas tecnologias possibilitam a recolha e transmissão de dados em cenários ondes redes comuns não são adequadas. Entretanto, devido às limitações usuais que são impostas aos equipamentos usados, a conservação de energia se torna indispensável para a sua utilização. Por conta disso, foram criados diversos mecanismos para redução no consumo de energia, uma grande parte das quais passa pela implementação de novos protocolos MAC. Este artigo explica como podem ser feitas implementações desse tipo de protocolo em um simulador, o que permite que se avalie o seu desempenho sem os custos associados com estudos no mundo real. Para tanto, foram comparados os simuladores mais comuns usados neste campo de estudo e o OMNeT++ foi escolhido como o mais adequado. Depois disso foi feita uma demonstração prática de como implementar um protocolo MAC nesse simulador e os resultados da simulação foram analisados.

Obstructive sleep apnea is a respiratory problem that has serious consequences for physical and mental health, but also in monetary terms, since traffic accidents and poor work performance, among other direct consequences, are attributed to it. It is estimated that between 9% and 38% of the world’s population has this disease. This is a multifactorial disease, therefore, there are several methods of detection and treatment; however, all of them cause discomfort to the patient, or to those around them. In this article we propose a system for the detection and control of obstructive sleep apnea that promises to overcome the drawbacks of the existing therapies, therefore, potentially making it a practical and effective solution for this disease. The proof of concept presented in this paper makes use of an electromyography sensor to collect the myoelectric signal produced by the genioglossus muscle. Surface electrodes provide the electromyography signals to an ESP32 microcontroller, which has the function of analyzing and comparing the data obtained with a predefined value of the apnea threshold. After the detection of an apnea, the circuit is able to create a stimulus signal that is applied directly to the muscle, so that airway occlusion does not occur, and the user does not wake up. The data from each use are automatically sent to a database to be viewed and analyzed at a later point.

Weeds, pathogens, and animal pests are among the pests that pose a threat to the productivity of crops meant for human consumption. Bird-caused crop losses pose a serious and costly challenge for farmers. This work presents a survey on bird deterrent solutions for crop protection. It first introduces the related concepts. Then, it provides an extensive review and categorization of existing methods, techniques, and related studies. Further, their strengths and limitations are discussed. Based on this review, current gaps are identified, and strategies for future research are proposed.