DM - GISC - Capítulos de Monografías

Permanent URI for this collection

https://hdl.handle.net/10016/6915

Browse

Recent Submissions

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Energy dependence of the ripple wavelength for ion-beam sputtering of silicon: experiments and theory
    (American Institute of Physics, 2012-08-05) Cañadas Castro, Mario; Gago, Raúl; Muñoz-García, Javier; Cuerno, Rodolfo
    In spite of the efforts devoted for the last 20 years to elucidating ion-beam sputtering (IBS) as an instance of surface self-organization, the classic view on the main mechanism inducing the morphological instability has been recently challenged. We report on the verification of a recent theoretical description of this nanopattern formation process for semiconducting targets, as driven by stress-induced, viscous flow of a thin amorphous layer that develops at the surface [M. Cuerno and R. Cuerno, Appl. Surf. Sci. 258, 4171 (2012)]. Through experiments on silicon as a representative case, we study the dependence of the ripple wavelength with the average ion energy, finding a linear dependence in the 0.3-1 keV range. This is explained within the viscous flow framework, taking into account the energy dependence of the number of displaced atoms generated by collision cascades in the amorphous layer, as predicted by previous models of ion-generated stress. For our analysis, we provide a systematic criterion to guarantee actual linear dynamics behavior, not affected by the onset of nonlinear effects that may influence the value of the ripple wavelength.
  • Thumbnail Image
    Publication
    Fair linking mechanisms for resource allocation with correlated player types
    (Springer, 2014-05) Santos, Agustín; Fernández Anta, Antonio; Cuesta, José A.; López Fernández, Luis
    Resource allocation is one of the most relevant problems in the area of Mechanism Design for computing systems. Devising algorithms capable of providing efficient and fair allocation is the objective of many previous research efforts. Usually, the mechanisms they propose use payments in order to deal with selfishness. Since using payments is undesirable in some contexts, a family of mechanisms without payments is proposed in this paper. These mechanisms extend the Linking Mechanism of Jackson and Sonnenschein introducing a generic concept of fairness with correlated preferences. We prove that these mechanisms have good incentive, fairness, and efficiency properties. To conclude, we provide an algorithm, based on the mechanisms, that could be used in practical computing environments.