Chaos theory is an important breakthrough in understanding nonlinear dynamical systems. It is generally accepted that chaotic systems involve transitivity, a high density of periodic points in metric space, and extreme sensitivity to changes in initial conditions. Many systems taught on undergraduate courses satisfy these conditions, such as electronic circuits or computer simulations of nonlinear dynamical systems. However, a good understanding of these concepts is broadly difficult to achieve on such courses, and especially so at the undergraduate level. In view of this, we have developed an interactive standalone graphical user interface, which is platform-independent. The interface didactically simulates six chaotic systems. It allows the user to study a particular system without prior knowledge of computer programming, demonstrating rich dynamical behaviour such as fixed points, periodic cycles and deterministic chaos. At the same time, the interface provides details of the simulation and the parameters used, as well as some of the leading references. We provide the complete code and a detailed installation guide, which should make it easy to use the interface reliably and with little overhead work. We also provide a comparison with other available software for reference, and as a guide to readers who would like to explore this fascinating subject in more depth or with alternative approaches. Lastly, we present the results of a survey

The dynamics of railway vehicles have changed from an essentially mechanical application into one that requires knowledge of sensors, electronics and computational processing. Industry 4.0 is a term that describes industrial activity by intelligent systems and solutions established on the concept of the Internet of Things (IoT). The present work illustrates the application of a conceptual cycle of an Internet of Things building a prototype, consisting on acquisition, processing and communication of data in the industrial context. Specifically, the monitoring of the dynamics of wagons using inertial sensors and algorithms that establish the fusion of sensors. The use of refined methods shows more reliable results in the use of low-cost sensors. Furthermore, the implementation of wireless communication enables the use of data in the creation of more complex analyses that can be applied in computational and instrumentation tools.

O presente estudo objetiva uma análise prospectiva dos óculos de realidade aumentada ou virtual considerando as patentes acessíveis nos repositórios internacionais WIPO, LENS, USPTO, o repositório de patentes nacional, INPI e trabalhos presentes na literatura referente ao tema. Com base no levantamento feito definiu-se o estado de desenvolvimento dessa tecnologia, sua expectativa de evolução para os próximos anos bem como suas diversas aplicações. Esse estudo também analisa o posicionamento dos principais países que desenvolvem tais tecnologias, bem como as empresas que despontam como maiores depositantes de patentes e a evolução temporal dos depósitos de patentes relacionados a óculos de realidade aumentada ou virtual.

The surface electromyography (sEMG) analysis can provide information on muscle fatigue status by estimation of muscle fibre conduction velocity (MFCV), a measure of the travelling speed of motor unit action potentials in muscle tissue. This paper proposes a technique for MFCV estimation using cross-correlation methods and variable bitstream modulation. The technique displays an estimate based on a set of data generated by the gain variation modulation, providing an average estimate of the MFCV. The observed trend of MFCV decrease correlates with the fatigue state of the observed muscle. Finally, the values found were compared with information from the literature, validating the method and showing the advantages of using variable modulation. Resumo: A análise da eletromiografia de superfície (EMGs) pode fornecer informações sobre o estado de fadiga muscular pela estimação da velocidade de condução de fibras musculares (VCFM), sendo uma medida da velocidade de deslocamento dos potenciais de ação no tecido muscular. O presente artigo propõe uma técnica para estimativa da VCFM utilizando métodos de correlação cruzada e modulação variável de fluxo de bits. A técnica exibe uma estimativa baseada em um conjunto de dados gerados pela variação do ganho de modulação, fornecendo uma estimativa média da VCFM. A estimativa representa uma diminuição da VCFM correlacionada com o estado de fadiga do músculo observado. Por fim, os valores encontrados foram comparados com informações da literatura, validando o método e mostrando as vantagens do uso da modulação variável.