Optimal error bounds for two-grid schemes applied to the Navier-Stokes equations

We consider two-grid mixed-finite element schemes for the spatial discretization of the incompressible Navier-Stokes equations. A standard mixed-finite element method is applied over the coarse grid to approximate the nonlinear Navier-Stokes equations while a linear evolutionary problem is solved over the fine grid. The previously computed Galerkin approximation to the velocity is used to linearize the convective term. For the analysis we take into account the lack of regularity of the solutions of the Navier-Stokes equations at the initial time in the absence of nonlocal compatibility conditions of the data. Optimal error bounds are obtained

Propaganda y opinión pública: “September Dossier”

En el nuevo orden mundial resultante tras el fin de la Guerra Fría, donde la opinión pública occidental eliminó la amenaza soviética de su imaginario inclinándose hacia posiciones no intervencionistas, el apoyo de la mayoría de la población se ha convertido en el factor fundamental a la hora de legitimar el uso de la fuerza en las democracias occidentales. Sabiendo la necesidad de construir tal consenso, a través de las élites y los medios de comunicación de masas, el Gobierno de Tony Blair lanzó en el año 2002 una campaña de propaganda y comunicación orientada a legitimar la intervención británica en la guerra de Iraq, persuadiendo a la opinión pública de la necesidad de actuar militarmente, ante el riesgo que suponían las armas de destrucción masiva. Para llevar a cabo la campaña propagandística basaron su mensaje en dos documentos oficiales publicados en prensa: “Iraq’s Weapons of Mass Destruction”, conocido como “September Dossier”, e “Iraq-Its infrastructure of concealment, deception and intimidation”, denominado por la prensa “Dodgy Dossier”. Las investigaciones posteriores demostraron que se manipuló la información de inteligencia para convencer a la opinión pública de los intereses que defendía el Gobierno BlairThe end of the Cold War brought along with one new international status quo, where Western public opinion removed the Soviet threat of its imaginary leaning towards non-interventionist positions. In this new world order, the support of the majority of the population has become the key when it comes to legitimize the use of force in the Western democracies. After knowing the need to build consensus through elites and mass media, Blair’s Government launched a propaganda campaign in 2002 in order to legitimize British military intervention in Iraq war, trying to convince public opinion about the threat of weapons of mass destruction. All this propaganda campaign was based in two official documents, published in mass media: Iraq’s Weapons of Mass Destruction, known as September Dossier; and, Iraq-Its infrastructure of concealment, deception and intimidation, popularly renowned as Dodgy Dossier. After the war, different inquires proved that the intelligence information included in these dossiers were manipulated in order to persuade public opinion about governmental interests

Grad-div stabilization for the time-dependent Boussinesq equations with inf-sup stable finite elements

In this paper we consider inf-sup stable nite element discretizations of the evolutionary Boussinesq equations with a grad-div type stabilization. We prove error bounds for the method with constants independent on the Rayleigh numbersMINECO grant MTM2016-78995-P (AEI)Junta de Castilla y León grant VA024P17Junta de Castilla y León grant VA105G18MINECO grant MTM2015-65608-

Fully Discrete Approximations to the Time-Dependent Navier–Stokes Equations with a Projection Method in Time and Grad-Div Stabilization

This paper studies fully discrete approximations to the evolutionary Navier{ Stokes equations by means of inf-sup stable H1-conforming mixed nite elements with a grad-div type stabilization and the Euler incremental projection method in time. We get error bounds where the constants do not depend on negative powers of the viscosity. We get the optimal rate of convergence in time of the projection method. For the spatial error we get a bound O(hk) for the L2 error of the velocity, k being the degree of the polynomials in the velocity approximation. We prove numerically that this bound is sharp for this method.MINECO grant MTM2016-78995-P (AEI)Junta de Castilla y León grant VA024P17Junta de Castilla y León grant VA105G18MINECO grant MTM2015-65608-

Protein S deficiency and novel oral anticoagulants: An intriguing case

Peer Reviewe

Country knowledge and familiarity effects on consumer perceived risk and rejection of foreign-made products

Las preocupaciones de los consumidores por los productos fabricados en el extranjero plantean interrogantes sobre lo que éstos conocen acerca del país de origen y la medida en que ese conocimiento se traduce en su rechazo de los productos extranjeros. El presente estudio examina tres tipos de variables de conocimiento acerca del país de origen que, junto con la experiencia de uso/familiaridad, actúan como antecedentes potenciales del riesgo percibido y, a su vez, de la reticencia de los consumidores españoles a comprar y de la (no) posesión de productos chinos. Los resultados revelan que el conocimiento medioambiental del país genera riesgo de auto-imagen/social, mientras que la experiencia de uso/familiaridad reduce tanto el riesgo de auto-imagen/social como el riesgo de rendimiento. Ambos tipos de riesgo afectan significativamente (positivamente) a la reticencia de los consumidores a comprar y (negativamente) a la posesión de productos extranjeros. Se discuten las implicaciones teóricas.Consumer concerns about foreign-made products raise questions about what consumers know about the COO and the extent to which such knowledge translates into their rejection of foreign products. The present examines three types country knowledge variables, along with familitarity/usage experience, as potential antecedents of perceived risk and, in turn, of Spanish consumers’ reluctance to buy and (non-)ownership of Chinese apparel products. The findings reveal that environmental country knowledge can engender self-image/social risk, whereas familiarity/usage experience reduces both self-image/social and performance risks. As expected, the two distinct risk types considered here significantly contributed to consumers’ reluctance to buy (positively) and product ownership (negatively). Theoretical implications are discussed

Uso de las TIC con alumnado con deficiencia auditiva en el aula ordinaria

Gracias al desarrollo que la informática está teniendo en los últimos años, así como su integración progresiva en nuestros Centros Educativos, está teniendo lugar un gran avance en la dinámica de trabajo de las aulas, ya que ésta influye directamente en los métodos de enseñanza y favorece el empleo de una mayor versatilidad en la presentación y el acceso a los diferentes contenidos curriculares eliminando barreras de comunicación. Teniendo en cuenta que la discapacidad auditiva supone una limitación sensorial que da lugar a diferentes barreras de comunicación, he de destacar que, en la actualidad, la tecnología está suponiendo una herramienta de gran importancia en cuanto a la eliminación de barreras. La Lengua de Signos es una lengua visual fundamentalmente, donde el movimiento, las expresiones faciales y el espacio juegan un papel muy importante. Es por ello que tanto los materiales utilizados como las actividades empleadas para su desarrollo requieren un formato visual que facilite la percepción y las reproducciones. Es en este punto donde la Pizarra Digital cobra especial importancia, pues supone un recurso que aporta gran cantidad de información visual, gráfica y auditiva, lo cual favorece tanto el trabajo con el alumnado con discapacidad auditiva como con el resto del alumnado oyente.Thanks to the development of computing in recent years, as well as its gradual integration into our schools, a great advance is taking place in the work dynamic of the classroom, which is already directly influencing methods of teaching and encouraging a greater versatility in the presentation of and access to the curricular contents. Taking into account that aural disability implies a sensory limitation that causes communicative barriers, I must stress that, currently, the technology is assuming a very important role in regards to the elimination of these obstacles. Sign language is fundamentally a visual language, where movement, facial expressions and space play a very important role. Because of this, so many of the materials used, like the activities used for their development require a visual format that facilitates perception and reproduction. At this point, the Interactive Whiteboard becomes specifically important, as a resource that provides a large quantity of visual, graphic and auditory information, which really helps working with pupils with hearing disabilities as well as those without

Efectos día de la semana en Rendimientos de la Bolsa Española

Cuando se contrasta los efectos día de la semana en los rendimientos bursátiles diarios, suponer que estas series diarias vienen generadas por un proceso ARMA univariante, con diferentes medias para cada día de la semana, puede ser muy restrictivo, y llevar a conclusiones erróneas. En este trabajo, se presenta una aproximación m´as general para contrastar la evidencia de efecto d´ıa de la semana, el cual incluye el mencionado supuesto como un caso particular. Como ejemplo, se estudia la existencia de efecto d´ıa de la semana en 25 rendimientos bursátiles de la Bolsa español

Static Analysis of Usefulness States in Transition P systems

Transition P Systems are a parallel and distributed computational model based on the notion of the cellular membrane structure. Each membrane determines a region that encloses a multiset of objects and evolution rules. Transition P Systems evolve through transitions between two consecutive configurations that are determined by the membrane structure and multisets present inside membranes. Moreover, transitions between two consecutive configurations are provided by an exhaustive non-deterministic and parallel application of evolution rules. But, to establish the rules to be applied, it is required the previous calculation of useful, applicable and active rules. Hence, computation of useful evolution rules is critical for the whole evolution process efficiency, because it is performed in parallel inside each membrane in every evolution step. This work defines usefulness states through an exhaustive analysis of the P system for every membrane and for every possible configuration of the membrane structure during the computation. Moreover, this analysis can be done in a static way; therefore membranes only have to check their usefulness states to obtain their set of useful rules during execution