Collective Coordinates Theory for Discrete Soliton Ratchets in the sine-Gordon Model

A collective coordinate theory is develop for soliton ratchets in the damped discrete sine-Gordon model driven by a biharmonic force. An ansatz with two collective coordinates, namely the center and the width of the soliton, is assumed as an approximated solution of the discrete non-linear equation. The evolution of these two collective coordinates, obtained by means of the Generalized Travelling Wave Method, explains the mechanism underlying the soliton ratchet and captures qualitatively all the main features of this phenomenon. The theory accounts for the existence of a non-zero depinning threshold, the non-sinusoidal behaviour of the average velocity as a function of the difference phase between the harmonics of the driver, the non-monotonic dependence of the average velocity on the damping and the existence of non-transporting regimes beyond the depinning threshold. In particular it provides a good description of the intriguing and complex pattern of subspaces corresponding to different dynamical regimes in parameter space

Teor?as impl?citas sobre la ense?anza en los ingenieros de sistemas que se desempe?an como docentes en las universidades de la ciudad de Ibagu?

109 p. Recurso Electr?nicoEs com?n el ingreso a la docencia de profesionales con formaci?n diferente a la pedag?gica, para orientar cursos de ?ndole especialmente pr?ctica. Es el caso de la Ingenier?a de Sistemas, programa que requiere casi en su totalidad profesores con profesiones espec?ficas, sobre todo, como es de esperarse, ingenieros de sistemas. El ingreso a la profesi?n docente se da por variadas circunstancias, pero siempre conlleva responsabilidades comunes, sobre todo en el campo de la pedagog?a y la did?ctica, indispensables para el ?xito de la labor docente que afrontan estos profesionales. A partir de la pr?ctica docente de estos profesores, surgen problem?ticas asociadas de una manera u otra a su accionar en el aula de clase, como son la deserci?n y la mortalidad acad?mica, las cuales preocupan y exigen respuestas de las directivas de instituciones educativas en todo el mundo. Estas problem?ticas pueden ser abordadas para su estudio desde diferentes perspectivas, en el caso de esta investigaci?n se hace un aporte a este campo desde las Teor?as Impl?citas, planteadas magistralmente por Javier Marrero, y desarrolladas por muchos otros docentes e investigadores en todo el mundo. Se logr? para esta investigaci?n la vinculaci?n de un n?mero importante de Ingenieros de Sistemas que se desempe?an como docentes en diferentes universidades de la ciudad de Ibagu?, en Colombia, a los cuales se les aplic? instrumentos dise?ados para identificar estilos de ense?anza a partir de los cuales develar las teor?as que de forma impl?cita animan su labor docente. Gracias a estos instrumentos se logra concluir, entre otras cosas, que la labor docente de estos ingenieros est? fundamentada en unas teor?as sobre la ense?anza, especialmente tienen preponderancia las teor?as interpretativa y productiva de acuerdo a los aportes de Javier Marrero, pero adem?s que estas teor?as impl?citas son din?micas, se transforman constantemente, y que la principal fuerza transformadora es la propia iniciativa de los docentes quienes se preocupan por alcanzar la perfecci?n en su compromiso con el sistema educativo. Otra de las principales conclusiones de este trabajo, es que a diferencia de otras investigaciones aplicadas a profesionales de otras disciplinas, se encontr? que entre los ingenieros de sistemas es sobresaliente la congruencia entre lo que estos plantean y lo que aplican al respecto del estilo de ense?anza que prefieren a la hora de cumplir su labor docente.Professionals getting into teaching without teacher training is common, particularly into courses of practical nature. This is the case of the Systems Engineering program which requires almost entirely teachers with specific professions, especially, as expected, systems engineers. Entering into teaching is given by different circumstances, but always entails common responsibilities, particularly in the field of pedagogy and didactics, indispensable for the success of teaching that these professionals face. Teaching practices of these teachers, are associated, in one way or another, with problems related to their actions in the classroom, such as desertion and academic mortality, which require special care and policy responses from educational institutions around the world. Study of these issues can be addressed from different perspectives. In the case of this research, a contribution is made in this field from the Implicit Theories, masterfully raised by Javier Marrero, and developed by many other teachers and researchers worldwide. For this research was achieved the colaboration of a large number of systems engineers working as teachers in different Universities in the city of Ibagu?, Colombia,. Instruments designed to identify learning styles ere applied to these subjects leading us to unveil the theories that implicitly encourage their teaching. Thanks to these instruments is possible to conclude, among other things, that the teaching practices of these engineers is based on a theory about teaching with especial preponderance on the interpretative and productive theories developed by Javier Marrero. Also, these Implicit theories are dynamic, constantly transformed, and the main transforming power is the initiative of teachers who care for perfection in their commitment to the education system. Another of the main conclusions of this work is that, unlike other research applied to professionals from other disciplines, we found that among systems engineers there is a remarkable consistency between what they pose and what they apply on the teaching style they prefer in performing their teaching activities. Key words: Systems Engineering, teaching practice, implicit theories, teaching styles

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An approach to emotion recognition in single-channel EEG signals: a mother child interaction

In this work, we perform a first approach to emotion recognition from EEG single channel signals extracted in four (4) mother-child dyads experiment in developmental psychology -- Single channel EEG signals are analyzed and processed using several window sizes by performing a statistical analysis over features in the time and frequency domains -- Finally, a neural network obtained an average accuracy rate of 99% of classification in two emotional states such as happiness and sadness20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin

Lepton number violating four-body tau lepton decays

We study the four-body tau^+- -> nu_tau l^+- l^+- X^-+ decays where l=e or mu and X=pi, K, rho and K^* mesons. These decay processes violate the total lepton number (|Delta L|=2) and can be induced by the exchange of Majorana neutrinos. We consider an scenario where these decays are dominated by the exchange of only one heavy neutrino which produces an enhancement of the decay amplitude via the resonant mechanism. Searches for these novel decay channels with branching fractions sensitivities of (10^-7) can provide constraints on the parameter space of the Majorana neutrinos which are stronger than the ones obtained from Delta L=2 decays of charged pseudoscalar mesons.Comment: REVTeX, 14 pages, 6 figures, four references added. Version accepted for publication in PR

Energy Flow Puzzle of Soliton Ratchets

We study the mechanism of directed energy transport for soliton ratchets. The energy flow appears due to the progressive motion of a soliton (kink) which is an energy carrier. However, the energy current formed by internal system deformations (the total field momentum) is zero. We solve the underlying puzzle by showing that the energy flow is realized via an {\it inhomogeneous} energy exchange between the system and the external ac driving. Internal kink modes are unambiguously shown to be crucial for that transport process to take place. We also discuss effects of spatial discretization and combination of ac and dc external drivings.Comment: 4 pages, 3 figures, submitted to PR

PI/PID controller stabilizing sets of uncertain nonlinear systems: an efficient surrogate model-based approach

AbstractClosed forms of stabilizing sets are generally only available for linearized systems. An innovative numerical strategy to estimate stabilizing sets of PI or PID controllers tackling (uncertain) nonlinear systems is proposed. The stability of the closed-loop system is characterized by the sign of the largest Lyapunov exponent (LLE). In this framework, the bottleneck is the computational cost associated with the solution of the system, particularly including uncertainties. To overcome this issue, an adaptive surrogate algorithm, the Monte Carlo intersite Voronoi (MiVor) scheme, is adopted to pertinently explore the domain of the controller parameters and classify it into stable/unstable regions from a low number of nonlinear estimations. The result of the random analysis is a stochastic set providing probability information regarding the capabilities of PI or PID controllers to stabilize the nonlinear system and the risk of instabilities. The minimum of the LLE is proposed as tuning rule of the controller parameters. It is expected that using a tuning rule like this results in PID controllers producing the highest closed-loop convergence rate, thus being robust against model parametric uncertainties and capable of avoiding large fluctuating behavior. The capabilities of the innovative approach are demonstrated by estimating robust stabilizing sets for the blood glucose regulation problem in type 1 diabetes patients