Symmetric intersections of Rauzy fractals

In this article we study symmetric subsets of Rauzy fractals of unimodular irreducible Pisot substitutions. The symmetry considered is reflection through the origin. Given an unimodular irreducible Pisot substitution, we consider the intersection of its Rauzy fractal with the Rauzy fractal of the reverse substitution. This set is symmetric and it is obtained by the balanced pair algorithm associated with both substitutions

Two-step benchmarking: Setting more realistically achievable targets in DEA

The models that set the closest targets have made an important contribution to DEA as tool for the best-practice benchmarking of decision making units (DMUs). These models may help defining plans for improvement that require less effort from the DMUs. However, in practice we often find cases of poor performance, for which closest targets are still unattainable. For those DMUs, we propose a two-step benchmarking approach within the spirit of context-dependent DEA and that of the models that minimize the distance to the DEA efficient frontier. This approach allows to setting more realistically achievable targets in the short term. In addition, it may offer different alternatives for planning improvements directed towards DEA efficient targets, which can be seen as representing improvements in a long term perspective. To illustrate, we examine an example which is concerned with the research performance of public Spanish universities

Casimir force calculations near the insulator-conductor transition in gold thin films

We present theoretical calculations of the Casimir force for Au thin films near the insulator-conductor transition that has been observed experimentally. The dielectric function of the Au thin films is described by the Drude-Smith model. The parameters needed to model the dielectric function such as the relaxation time, plasma frequency and the backscattering constant depend on the thickness of the film. The Casimir force decreases as the film thickness decreases until it reaches a minimum after which the force increases again. The minimum of the force coincides with the critical film thickness where a percolation conductor-insulator occurs.Comment: 5 figures, 1 tabl

La vulneración empresarial del derecho de huelga y responsabilidad por daños y perjuicios

Existen conductas empresariales de muy diversa naturaleza que pueden dar lugar a la transgresión del derecho de huelga. En estos casos se hace necesario reparar los daños que tales conductas provocan, tanto en el plano individual (trabajador) como en el plano colectivo (sindicatos u órganos de representación unitaria), teniendo en cuenta que la indemnización que derive de ello debe cumplir una función ejemplarizante, además de la propiamente reparadora. En el presente estudio, siguiendo los criterios que han ido sentando nuestros Tribunales, se identifican distintas conductas empresariales susceptibles de conculcar el derecho de huelga, a la par que se analizan todas y cada una de las partidas que debieran estar presentes a la hora de calcular el monto indemnizatorio, así como los criterios de valoración a tener en cuenta en estos casos.There are business behaviors of diverse nature that can lead to the violation of the right to strike. In these cases it is necessary to repair the damage that such behavior causes, both at the individual (worker) and the collective level (unions), given that compensation resulting from this should play a role exemplary, besides pure restorative. In the present study, the criteria that have been establishing in our Courts, are identified different business conducts which may violate the right to strike, and at the same time are analyzed each of the items that should be present when calculating the amount of compensation and the assessment criteria are identified to consider in these cases

Reduction of the Casimir force using aerogels

By using silicon oxide based aerogels we show numerically that the Casimir force can be reduced several orders of magnitude, making its effect negligible in nanodevices. This decrease in the Casimir force is also present even when the aerogels are deposited on metallic substrates. To calculate the Casimir force we model the dielectric function of silicon oxide aerogels using an effective medium dielectric function such as the Clausius-Mossotti approximation. The results show that both the porosity of the aerogel and its thickness can be use as control parameters to reduce the magnitude of the Casimir force.Comment: to appear J. Appl. Phy