A proposal for dependent optimization in scalabale region-based coding systems

We address in this paper the problem of optimal coding in the framework of region-based video coding systems, with a special stress on content-based functionalities. We present a coding system that can provide scaled layers (using PSNR or temporal content-based scalability) such that each one has an optimal partition with optimal bit allocation among the resulting regions. This coding system is based on a dependent optimization algorithm that can provide joint optimality for a group of layers or a group of frames.Peer ReviewedPostprint (published version

A morphological approach for segmentation and tracking of human faces

A new technique for segmenting and tracking human faces in video sequences is presented. The technique relies on morphological tools such as using connected operators to extract the connected component that more likely belongs to a face, and partition projection to track this component through the sequence. A binary partition tree (BPT) is used to implement the connected operator. The BPT is constructed based on the chrominance criteria and its nodes are analyzed so that the selected node maximizes an estimation of the likelihood of being part of a face. The tracking is performed using a partition projection approach. Images are divided into face and non-face parts, which are tracked through the sequence. The technique has been successfully assessed using several test sequences from the MPEG-4 (raw format) and the MPEG-7 databases (MPEG-1 format).Peer ReviewedPostprint (published version

Medieval medical recipes in London, Wellcome Library, MSS 404 and 5262

This paper seeks to explore the similarities between different unidentified texts, chiefly London, Wellcome Library MSS 404 and 5262, which are catalogued as a leechbook and a recipe collection, respectively. For the purpose, a brief description of each text will be first provided; then, the recipes in these texts will be analysed and their connections will be highlighted with a view to casting some light on possibly shared material and textual tradition.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Coupled-wave surface-impedance analysis of extraordinary transmission through single and stacked metallic screens

In this paper we present an efficient Coupled-wave surface-impedance method for the analysis of extraordinary optical transmission (EOT) through single and stacked realistic metallic screens under normal and oblique incidence, including possible dielectric interlayers. The proposed theory is valid for the complete frequency range where EOT has been reported, including microwaves and optics. Electromagnetic simulations validate the results of the model, which allows for a fast and accurate characterization of the analyzed structures

Inertial waves in rapidly rotating flows: a dynamical systems perspective

An overview of recent developments in a wide variety of enclosed rapidly rotating flows is presented. Highlighted is the interplay between inertial waves, which have been predicted from linear inviscid considerations, and the viscous boundary layer dynamics which result from instabilities as the nonlinearities in the systems are increased. Further, even in the absence of boundary layer instabilities, nonlinearity in the system often leads to complicated interior flows due to subcritical instabilities, Eckhaus bands and heteroclinic dynamics. The ensuing spatio-temporally complex dynamics is analysed in terms of equivariant dynamical systems, providing a general perspective for the wide range of dynamics involved.Postprint (author's final draft

Mergers and acquisitions and bank performance in Europe: the role of strategic similarities

An unprecedented process of financial consolidation has taken place in the European Union over the past decade. Building on earlier US evidence, we examine the impact of strategic similarities between bidders and targets on post-merger financial performance. We find that, on average, bank mergers in the European Union resulted in improved return on capital. By making the assumption that balance-sheet resource allocation is indicative of the strategic focus of banks, we also find significantly different results for domestic and cross-border mergers. For domestic deals, it could be quite costly to integrate dissimilar institutions in terms of their loan, earnings, cost, deposits and size strategies. For cross-border mergers and acquisitions (M&As), differences of merging partners in their loan and credit risk strategies are conducive to a higher performance whereas diversity in their capital, cost structure as well as technology and innovation investments strategies are counterproductive from a performance standpoint. JEL Classification: G21, G34banks, M&As, strategic similarities

Social Mobility and Demand for Redistribution. A Comparative Analysis

The literature on preferences for redistribution has paid little attention to the effect of social mobility on the demand for redistribution, which is in contrast with the literature on class-voting, where studies on the effect of social mobility has been very common. Some works have addressed this issue but no systematic test of the hypotheses connecting social mobility and preferences has been done. In this paper we use the diagonal reference models to estimate the effect of origin and destination class on preferences for redistribution in a sample of European countries using data from the European Social Survey. Our findings indicate that social origin matters to a little extent to explain preferences, as newcomers tend to adopt the preferences of the destination class. Moreover, we have found only limited evidence supporting the acculturation hypothesis and not support for the status maximization hypothesis. Furthermore, the effect of social origin varies largely between countries. In a second step of the analysis we investigate what are the national factors explaining this variation. The empirical evidence we present leads to conclude that high rates of upward social mobility sharply reduce the effect of social origin on preferences for redistributionUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Small aspect ratio Taylor-Couette flow: onset of a very-low-frequency three-torus state

The nonlinear dynamics of Taylor-Couette flow in a small aspect ratio annulus (where the length of the cylinders is half of the annular gap between them) is investigated by numerically solving the full three-dimensional Navier-Stokes equations. The system is invariant to arbitrary rotations about the annulus axis and to a reflection about the annulus half-height, so that the symmetry group is SO(2)×Z2. In this paper, we systematically investigate primary and subsequent bifurcations of the basic state, concentrating on a parameter regime where the basic state becomes unstable via Hopf bifurcations. We derive the four distinct cases for the symmetries of the bifurcated orbit, and numerically find two of these. In the parameter regime considered, we also locate the codimension-two double Hopf bifurcation where these two Hopf bifurcations coincide. Secondary Hopf bifurcations (Neimark-Sacker bifurcations), leading to modulated rotating waves, are subsequently found and a saddle-node-infinite-period bifurcation between a stable (node) and an unstable (saddle) modulated rotating wave is located, which gives rise to a very-low-frequency three-torus. This paper provides the computed example of such a state, along with a comprehensive bifurcation sequence leading to its onset.Postprint (published version

Nonlinear and detuning effects of the nutation angle in precessionally-forced rotating cylinder flow

The flow in a rapidly rotating cylinder forced to precess through a nutation angle a is investigated numerically, keeping all parameters constant except a, and tuned to a triadic resonance at a = 1º. When increasing a, the flow undergoes a sequence of well- characterized bifurcations associated with triadic resonance, involving heteroclinic and homoclinic cycles, for a up to about 4º. For larger a, we identify two chaotic regimes. In the first regime, with a between about 4º and 27º, the bulk flow retains remnants of the helical structures associated with the triadic resonance, but there are strong nonlinear interactions between the various azimuthal Fourier components of the flow. For the larger a regime, large detuning effects lead to the triadic resonance dynamics being completely swamped by boundary layer eruptions. The azimuthal mean flow at large angles results in a large mean deviation from solid-body rotation and the flow is characterized by strong shear at the boundary layers with temporally chaotic eruptions.Postprint (author's final draft

Intergenerational social mobility in Spain between 1956 and 2011: the role of educational expansion and economic modernisation in a late industrialised country

This article explores intergenerational class mobility patterns and the role played by education in Spain usingcounterfactuals. Both men and women born from 1926 to 1981 are analysed, meaning the study covers a periodof profound economic and educational advances in a late-industrialised country. The results suggest that, amongthe cohorts born in the 1970s, men have experienced a slight increase in socialfluidity, while women haveexperienced a substantial increase that seems partially driven by their massively increased access to routine non-manual positions independent of their social origins. Inequality of educational opportunities and class returns toeducation have declined, whereas the direct effect of social origins (DESO) has remained constant for men andhas decreased considerably for women. The counterfactual analysis shows that the slight increase in socialfluidity for men is mainly driven by educational expansion. For women, theDESOand educational expansionaccount for a great share of increasingfluidity. Therefore, certain assumptions made by theModernization TheoryandGoldthorpe’s Theory of Social Mobilitycan be put into questio