An observer-based vaccination control law for an SEIR epidemic model based on feedback linearization techniques for nonlinear systems

This paper presents a vaccination strategy for fighting against the propagation of epidemic diseases. The disease propagation is described by an SEIR (susceptible plus infected plus infectious plus removed populations) epidemic model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes the contacts among susceptible and infected more difficult. The vaccination strategy is based on a continuous-time nonlinear control law synthesised via an exact feedback input-output linearization approach. An observer is incorporated into the control scheme to provide online estimates for the susceptible and infected populations in the case when their values are not available from online measurement but they are necessary to implement the control law. The vaccination control is generated based on the information provided by the observer. The control objective is to asymptotically eradicate the infection from the population so that the removed-by-immunity population asymptotically tracks the whole one without precise knowledge of the partial populations. The model positivity, the eradication of the infection under feedback vaccination laws and the stability properties as well as the asymptotic convergence of the estimation errors to zero as time tends to infinity are investigated.

Adaptive variable structure control law for a variable speed wind turbine

Presentado en el 13th WSEAS International Conference on Automatic Control, Modelling and Simulation, ACMOS'11

Sliding mode control law for a variable speedwind turbine

Modern wind turbines are designed in order to work in variable speed operations. To perform this task, wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed generators is improving the system efficiency compared to fixed speed generators, because turbine speed can be adjusted as a function of wind speed in order to maximize the output power. However this system requires a suitable speed controller in order to track the optimal reference speed of the wind turbine. In this work, a sliding mode control for variable speed wind turbines is proposed. An integral sliding surface is used, because the integral term avoids the use of the acceleration signal, which reduces the high frequency components in the sliding variable. The proposed design also uses the vector oriented control theory in order to simplify the generator dynamical equations. The stability analysis of the proposed controller has been carried out under wind variations and parameter uncertainties by using the Lyapunov stability theory. Finally simulated results show, on the one hand that the proposed controller provides a high-performance dynamic behavior, and on the other hand that this scheme is robust with respect to parameter uncertainties and wind speed variations, that usually appear in real systems.

An adaptive sliding mode control law for the power maximization of the wind turbine system

POWERENG 2011

Administratzaileen erantzunkizuna: akzio soziala/akzio indibiduala

[EU]Gradu Bukaerako Lan honek bi helburu nagusi ditu. Alde batetik, gure praktika profesionala ikertzea eta hobetzea. Bestetik, administratzaileen erantzukizunaren eremuan liskar egoerak sortzen dituzten egoerei eta zalantzei erantzuna ematea, nolabait, eremu honetan, ideiak argitu eta sendotzeko helburuarekin. Lanketa hori egiteko Graduan zehar barneratutako hainbat ezagutza eta zenbait adituren ezagutza teorikoen ekarpenak egiten dira lanean. Nagusiki, lau aspektu izango dira lan honen aztertze objektu. Horrela, lehen atal batean, erantzukizunaren ikuspegi orokorra landuko dugu. Behin, eremu hau azterturik, Legeak aurreikusten dituen akzioen aspektu garrantzitsuenetara joko dugu. Ondoren, modu labur batean bada ere, aipamen txiki bat egingo diogu konkurtso egoeran sortzen diren egoerei. Azkenik, urteetan zalantza egoera sortu duen gaiari erreparatuko diogu, hau da, preskripzioaren gaia. Proiektuak ondorioztatzen du, erantzukizunaren eremuan Legegileak jasotzen dituen aldaketek helburu dutela, arauketa osatuago bat eskaintzea.

Addressing students' difficulties with Faraday's law: A guided problem solving approach

In traditional teaching, the fundamental concepts of electromagnetic induction are usually quickly analyzed, spending most of the time solving problems in a more or less rote manner. However, physics education research has shown that the fundamental concepts of the electromagnetic induction theory are barely understood by students. This article proposes an interactive teaching sequence introducing the topic of electromagnetic induction. The sequence has been designed based on contributions from physics education research. Particular attention is paid to the relationship between experimental findings (macroscopic level) and theoretical interpretation (microscopic level). An example of the activities that have been designed will also be presented, describing the implementation context and the corresponding findings. Since implementing the sequence, a considerable number of students have a more satisfactory grasp of the electromagnetic induction explicative model. However, difficulties are manifested in aspects that require a multilevel explanation, referring to deep structures where the system description is better defined.

La libertad de información y revelación de datos fiscales

[ES]Con el desarrollo de las nuevas tecnologías, se han facilitado las relaciones, acortado el tiempo de espera y agilizado los trámites con la Administración Pública. Estos adelantos, sin embargo, han propiciado que sea necesario proporcionar información de carácter personal de los ciudadanos, que en la mayoría de los casos es sensible. Es por esto que en los últimos años se han ido modificando e introduciendo nuevas leyes que permiten proteger estos datos de carácter personal. Cuando un contribuyente realiza sus obligaciones tributarias suministra datos de carácter personal a Hacienda, datos que están protegidos por la Ley Orgánica de Protección de Datos. El Sistema Tributario deber ser eficaz y transparente. Sin embargo, cabe preguntarse dónde se sitúa el límite a esa transparencia. Con el fin de que la transparencia sea máxima y de que la ciudadanía se conciencie de la importancia de cumplir con sus obligaciones tributarias el legislador se ha planteado la posibilidad de publicar una lista de deudores y las sentencias firmes condenatorias de grandes defraudadores. Esta publicación de las listas aparentemente vulneraría los derechos de los ciudadanos en lo referente a la protección de datos con opiniones encontradas. Tras informes de diferentes organismos se ha llegado al Proyecto de Ley de Modificación parcial de la Ley 58/2003, General Tributaria (Boletín Oficial de las Cortes Generales del 30 de abril de 2015), que permitiría publicar las listas con ciertos límites: publicación únicamente del nombre de la persona física o jurídica y DNI o NIF. Además, para permitir la publicación de las sentencias firmes de los defraudadores, recientemente se ha aprobado el Proyecto de reforma de la Ley Orgánica del Poder Judicial.