Los determinantes de la confianza del comprador online. Comparación con el caso de subasta

[ES] Los trabajos de investigación sobre comercio electrónico en Internet ocupan gran parte de la investigación de marketing, pero son pocos aún los que se han ocupado de estudiar el sistema de subasta. Ante las peculiares características de una compra online, transmitir confianza al consumidor en este contexto es uno de los retos más importantes y difíciles en comparación con la compra offline. No obstante, es de esperar que las señales generadoras de confianza sean diferentes en la compra online por subasta que en la compra online en otros sitios web.

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.