The use of mobile phones by students at school : reasons and consequences

A sociedade contemporânea vivencia a era da conexão, mobilidade e ubiquidade na comunicação humana, desencadeando novas formas de interação e colaboração em redes e ambientes on-line. Neste contexto, há uma disseminação crescente e acelerada do uso de aparelhos móveis, e inevitavelmente esse uso começa a ocorrer com mais frequência na escola. O objetivo desta pesquisa foi compreender os motivos e desdobramentos do uso dos aparelhos celulares pelos estudantes na escola. A metodologia utilizada foi a Teoria Fundamentada (Glaser; Strauss, 1999) e os dados foram obtidos por meio de interações no Twitter, questionário e entrevistas on-line com estudantes que estivessem acessando a internet na escola por meio de um aparelho móvel. Com base nos dados coletados, foram elaboradas quatro categorias explanatórias do uso do celular na escola por estudantes: regras, uso didático, motivação e consequências. A partir da análise dos dados, nota-se que, em geral, as escolas tendem a proibir o uso, contudo, os estudantes costumam transgredir, utilizando seus celulares em virtude do tempo livre na escola ou do tédio nas aulas. Além disso, relata-se o uso com a finalidade de acesso às redes sociais, de distração e de pesquisa de conteúdo relacionado às disciplinas. Neste cenário, indica-se que a escola compreenda as questões sociais e culturais relativas à cibercultura dos jovens e perceba o fenômeno como uma oportunidade de aproximação e aprendizagem mútua.Contemporary society experiences the era of connection, mobility and ubiquity in human communication, unleashing new forms of interaction and collaboration in networks and online environments. In this context, there is a growing and rapid expansion of the use of mobile devices, which inevitably begins to occur more frequently in schools. The aim of this research was to understand the reasons and consequences of the use of cell phones by students in school. The methodology adopted was the Grounded Theory (Glaser; Strauss, 1999) and data were obtained through interactions on Twitter, online questionnaires and interviews with students who were using a mobile device at school to access the internet. Based on the collected data, four explanatory categories related to the use of cell phones by students at school were created: rules, didactic use, motivation, and consequences. Through the process of data analysis, it is noted that, in general, schools tend to prohibit cell phones' use, however; students often transgress this prohibition and utilize their phones due to having free time at school or to being bored in class. In addition, the need to access social networks for entertainment and to search for something related to the subjects is reported. In this scenario, it is pointed out that schools should try to comprehend the social and cultural issues related to the cyberculture and the youth, as well as realize the phenomenon as an opportunity of approaching students and of mutual learning

Lyapunov-like Conditions of Forward Invariance and Boundedness for a Class of Unstable Systems

We provide Lyapunov-like characterizations of boundedness and convergence of non-trivial solutions for a class of systems with unstable invariant sets. Examples of systems to which the results may apply include interconnections of stable subsystems with one-dimensional unstable dynamics or critically stable dynamics. Systems of this type arise in problems of nonlinear output regulation, parameter estimation and adaptive control. In addition to providing boundedness and convergence criteria the results allow to derive domains of initial conditions corresponding to solutions leaving a given neighborhood of the origin at least once. In contrast to other works addressing convergence issues in unstable systems, our results require neither input-output characterizations for the stable part nor estimates of convergence rates. The results are illustrated with examples, including the analysis of phase synchronization of neural oscillators with heterogenous coupling

A step beyond Tsallis and Renyi entropies

Tsallis and R\'{e}nyi entropy measures are two possible different generalizations of the Boltzmann-Gibbs entropy (or Shannon's information) but are not generalizations of each others. It is however the Sharma-Mittal measure, which was already defined in 1975 (B.D. Sharma, D.P. Mittal, J.Math.Sci \textbf{10}, 28) and which received attention only recently as an application in statistical mechanics (T.D. Frank & A. Daffertshofer, Physica A \textbf{285}, 351 & T.D. Frank, A.R. Plastino, Eur. Phys. J., B \textbf{30}, 543-549) that provides one possible unification. We will show how this generalization that unifies R\'{e}nyi and Tsallis entropy in a coherent picture naturally comes into being if the q-formalism of generalized logarithm and exponential functions is used, how together with Sharma-Mittal's measure another possible extension emerges which however does not obey a pseudo-additive law and lacks of other properties relevant for a generalized thermostatistics, and how the relation between all these information measures is best understood when described in terms of a particular logarithmic Kolmogorov-Nagumo average