Measuring the Complexity of Continuous Distributions

We extend previously proposed measures of complexity, emergence, and self-organization to continuous distributions using differential entropy. This allows us to calculate the complexity of phenomena for which distributions are known. We find that a broad range of common parameters found in Gaussian and scale-free distributions present high complexity values. We also explore the relationship between our measure of complexity and information adaptation.Comment: 21 pages, 5 Tables, 4 Figure

Concentración y pluralismo en el nuevo escenario audiovisual español. Análisis de la absorción de la cadena Cuatro por Telecinco

Este trabajo intenta analizar la profunda reorganización que está teniendo lugar en la televisión española tras los acuerdos de fusión que se han producido entre diferentes cadenas. La abundancia de cambios regulatorios, especialmente durante los años 2009 y 2010, ha propiciado la puesta en marcha de acuerdos entre diferentes empresas del sector televisivo. La primera de estas operaciones ha sido la absorción de Cuatro por Telecinco, así como la toma de participación de la cadena de Mediaset y de Telefónica del 44% de Digital+, mientras que la segunda, y largamente anunciada, corresponde a la absorción de La Sexta por Antena 3. El objeto de análisis de este artículo corresponde, no obstante, a la primera de estas operaciones, puesto que ya ha sido analizada por las autoridades de la competencia. En cualquier caso, estas operaciones corporativas han dado lugar a una gran concentración en el sector audiovisual, que puede afectar a la pluralidad de los medios audiovisuales españoles y conducir incluso a una situación de "duopolio" televisivo.This work tries to analize the whole reorganization which is taking place in the Spanish television after the merger agreements that have occurred between different channels. The abundance of regulation changes, especially during 2009 and 2010, with the approval of the new Audiovisual Law, the state-owned TV financing model, the introduction of DTT Pay TV, and others different measures, has given green light to the agreements between Telecinco channel and Cuatro TV and the absorption of La Sexta by Antena 3. The object of analysis for this item, however, the first of these operations, as has already been analyzed by the competition authorities. In any case, these corporate operations have resulted in high concentrations in the audiovisual sector, which can affect the plurality of the Spanish media and even led to a situation of "duopoly".Aquest treball intenta analitzar la profunda reorganització que està tenint lloc en la televisió espanyola després dels acords de fusió que s'han produït entre diferents cadenes. L'abundància de canvis regulatoris, especialment durant els anys 2009 i 2010, ha propiciat acords entre diferents empreses del sector televisiu. La primera d'aquestes operacions ha estat l'absorció de Quatre per Telecinco, així com la presa de participació de la cadena de Mediaset i de Telefónica del 44% de Digital+, mentre que la segona, i llargament anunciada, correspon a l'absorció de La Sexta per Antena 3. L'objecte d'anàlisi d'aquest article correspon, no obstant això, a la primera d'aquestes operacions, ja que ja ha estat analitzada per les autoritats de la competència. En qualsevol cas, aquestes operacions corporatives han donat lloc a una gran concentració en el sector audiovisual, que pot afectar a la pluralitat dels mitjans audiovisuals espanyols i conduir fins i tot a una situació de "duopoli" televisiu

El bosque: cobijo del arte y metáfora de regreso desde 1968

The landscape genre resurfaced with renewed forces beginning in the sixties of the twentieth century through the land art and the earthworks. The pioneers Americans felt a special love for the desert and the places which are difficult to access by placing their works, a gesture that broke the relations of the work of art with the traditional places of exposure (museums, galleries). At the same time, is also accentuated the mental dimension of art, opening the way toward the conceptual. In recent years a second generation of creators, which also operate in the nature, choose the forest as scenario of their proposals. The object of this work is to demonstrate how the works of these artists are warns a intention of double return: on the one hand, to the materiality of a work of art and at the other end to a metaphorical origin through the figure of the forest, a space that, since the eruption of the environmentalism is understood as a synonym for paradise.El género del paisaje resurgió con fuerzas renovadas a partir de los años sesenta del siglo XX a través del land art y los earthworks. Los pioneros norteamericanos sintieron una especial predilección por el desierto y los lugares de difícil acceso para colocar sus obras, gesto que rompía las relaciones de la obra de arte con los lugares tradicionales de exposición (museos, galerías). Al tiempo, se acentuaba también la dimensión mental del arte, abriendo la vía hacia el conceptual. En los últimos años una segunda generación de creadores, que también operan en la naturaleza, elige el bosque como escenario de sus propuestas. El objeto de este trabajo es poner de manifiesto cómo en la obra de estos artistas se advierte una intención de doble retorno: por una parte, a la materialidad de la obra de arte y por otra a un origen metafórico a través de la figura del bosque, espacio que, desde la irrupción del ecologismo se entiende como sinónimo de paraíso

Nuevos restos de pintura mural medieval en Burgos : La iglesia de San Miguel de Neila

En la iglesia de San Miguel de Neila (Burgos) se conservan restos de pintura medieval. A pesar de verse, en la actualidad, tan sólo una pequeña superficie, es interesante como una aportación a la pintura románica en Castilla.In the San Miguel parish church of Neila (Burgos) there are remains of medieval asall painting. Actually we can see just a little fragment, but it's interesting as a new contribution to the Romanesque wall painting in Castilla

Multi-output kernel adaptive filtering with reduced complexity

In this paper, two new multi-output kernel adaptive filtering algorithms are developed that exploit the temporal and spatial correlations among the input-output multivariate time series. They are multi-output versions of the popular kernel least mean squares (KLMS) algorithm with two different sparsification criteria. The first one, denoted as MO-QKLMS, uses the coherence criterion in order to limit the dictionary size. The second one, denoted as MO-RFF-KLMS, uses random Fourier features (RFF) to approximate the kernel functions by linear inner products. Simulation results with synthetic and real data are presented to assess convergence speed, steady-state performance and complexities of the proposed algorithms.This work was supported by the Ministerio de Ciencia, Innovación y Universidades and AEI/FEDER funds of the E.U., under grant PID2019-104958RB-C43 (ADELE)

Homotopy continuation for vector space interference alignment in MIMO X networks

In this paper we propose an algorithm to design interference alignment (IA) precoding and decoding matrices for MIMO X networks (XN). The proposed algorithm is rooted in the homotopy continuation techniques commonly used to solve systems of nonlinear equations. Homotopy methods find the solution of a target system by smoothly deforming the known solutions of a start system which can be trivially solved. The key observation leading to a simple start system is realizing that the inverse IA problem, i.e., finding the channels that satisfy the IA conditions given a set of precoders and decoders, is linear and, therefore, a convenient trivial system. Once the start system has been solved, standard prediction and correction techniques are applied to track the solution all the way to the target system. Our results show that the proposed algorithm is able to consistently find solutions achieving the maximum number of degrees of freedom (DoF) whereas alternating minimization techniques, which typically work well for the interference channel (IC), repeatedly fail for the XN. Further, the algorithm provides insights into the feasibility of alignment in MIMO X networks for which theoretical results are scarce.This work was supported by the Spanish Government, Ministerio de Ciencia e Innovación (MICINN), under project COSIMA (TEC2010-19545-C04-03), project COMONSENS (CSD2008-00010, CONSOLIDER-INGENIO 2010 Program) and FPU grant AP2009-1105

Statistical analysis of single-beam interference alignment schemes

In this work, we derive analytical approximate expressions for the user rates achievable by interference alignment (IA) algorithms in single-beam multiple-input multiple-output (MIMO) networks for a fixed channel realization. Unlike previous works that perform a large-system analysis in which the number of users, antennas, or streams is required to tend to infinity, in this paper we only require that the number of different IA solutions (precoders and decoders) for the given scenario is sufficiently high, which typically happens even for moderate-size feasible networks. Based on the assumption that the IA beamformers for a given channel realization are random vectors isotropically distributed on the complex unit sphere, we characterize the user rates by averaging over the (possible finite) set of IA solutions. Some simulation results show the accuracy of the proposed rate expressions.This work was supported by the Ministerio de Economía y Competitividad (MINECO), Spain, under project RACHEL (TEC2013-47141-C4-3-R) and FPI grant BES-2014-069786

On the spatial degrees of freedom benefits of reverse TDD in multicell MIMO networks

In this paper we study the degrees of freedom (DoF) achieved by interference alignment (IA) for cellular networks in reverse time division duplex (R-TDD) mode, a new configuration associated to heterogeneous networks. We derive a necessary feasibility condition for interference alignment in the multi-cell R-TDD scenario, which is then specialized to the particular case of symmetric demands and antenna distribution. We show that, for those symmetric networks for which the properness condition holds with equality, R-TDD does not improve the DoF performance of conventional synchronous TDD systems. Nevertheless, our simulation results indicate that, in more asymmetric scenarios, significant DoF benefits can be achieved by applying the R-TDD approach.This work has been supported by the Ministerio de Economía y Competitividad (MINECO) of Spain under grant TEC2013-47141- C4-R (RACHEL project) and FPI grant BES-2014-069786