Labor Demand and Information Technologies: Evidence for Spain, 1980-2005

Using the EU KLEMS dataset we test the capital-skill complementarity hypothesis in a cross-section of sectors in Spain between 1980 and 2005. We analyze three groups of workers, who are classed according to skill level: high, medium and low. Capital assets have been broken down into ICT (information and communication technologies) assets and non-ICT assets. Acquisition and usage costs of ICT assets declined throughout the period studied, both in absolute terms and relative to the other capital assets and workers. Our principal finding is that the substitutibility between workers and ICT assets falls as worker skill level rises. In fact, the ICT assets were strongly complement with highly skilled workers and were not substitutive with them. Throughout the period analyzed, the fraction of employed medium- and high-skill workers rose by 21% and 12%, respectively, to the disadvantage of low-skill workers. After decomposing these changes, we found that the latter were dominated by an ajustment within sectors more than by a composition effect or adjustment between sectors. These adjustments may be explained by reference to the estimated elasticities of substitution.capital-skill complementarity, ICT, translog cost function, elasticity of substitution.

Domogis: Prototipo de un interfaz del sistema de control de un edificio integrado en un SIG

Este trabajo trata de la utilización de los Sistemas de Información Geográfica (SIG) en uno de las nuevos requerimientos de la arquitectura, el control domótico. El objetivo es el desarrollo de un interfaz de comunicación del Sistema de Control de un Edificio (SCE) integrado en un SIG. La consecución de este objetivo implica previamente el desarrollo del SIG del Campus de Montegancedo sede de la Facultad de Informática de la UPM y la creación de un interfaz integrado en el SIG, desarrollado en lenguaje de programacion C# de Microsoft. Este interfaz dirige al usuario en la realización de ciertas tareas de control domótico de las instalaciones urbanas y edificios del Campus universitario, como evaluar, monotorizar y gestionar datos procedentes de sensores estratégicamente situados en dicho Campus

CCD image sensor induced error in PIV applications

The readout procedure of charge-coupled device (CCD) cameras is known to generate some image degradation in different scientific imaging fields, especially in astrophysics. In the particular field of particle image velocimetry (PIV), widely extended in the scientific community, the readout procedure of the interline CCD sensor induces a bias in the registered position of particle images. This work proposes simple procedures to predict the magnitude of the associated measurement error. Generally, there are differences in the position bias for the different images of a certain particle at each PIV frame. This leads to a substantial bias error in the PIV velocity measurement (~0.1 pixels). This is the order of magnitude that other typical PIV errors such as peak-locking may reach. Based on modern CCD technology and architecture, this work offers a description of the readout phenomenon and proposes a modeling for the CCD readout bias error magnitude. This bias, in turn, generates a velocity measurement bias error when there is an illumination difference between two successive PIV exposures. The model predictions match the experiments performed with two 12-bit-depth interline CCD cameras (MegaPlus ES 4.0/E incorporating the Kodak KAI-4000M CCD sensor with 4 megapixels). For different cameras, only two constant values are needed to fit the proposed calibration model and predict the error from the readout procedure. Tests by different researchers using different cameras would allow verification of the model, that can be used to optimize acquisition setups. Simple procedures to obtain these two calibration values are also described

Recuperación de las interacciones entre el haya (Fagus sylvatica) y los hongos ectomicorrícicos 140 años después del fin de la actividad minera

Even the increasing use of restoration, it does not always imply a shortterm answer in ecosystems that guarantees the recovery of their structure, functions, and services. So far, most studies evaluating ecosystem recovery have used metrics that ignore the complexity needed to structure communities of organisms that form ecosystems. Here, we analyze the recovery of species interactions (metric with a certain level of complexity) in a large time scale ('100 years). In particular, we characterized, using molecular identification, the ectomicorrhyzal (EcM) fungal communities present in 18 beech trees inside and seven outside an ancient iron in Navarra (northern Spain), in use from the XIV century until 140 years ago, as well as seven beech trees from a nearby oldgrowth forest. Species richness of EcM fungi was similar for the three locations, while differences were found for species composition in the area damaged by mining and compare to outside the mine and the reference beech forest. Our results suggest the need to assess ecosystem recovery with more complex metrics (e.g. architecture of interaction networks) in order to accurately estimate the real time required for ecosystems to fully recover. © 2019 Los Autores.Este trabajo ha sido financiado por el Plan Nacional de Investigación RETOS (CGL2015-70452-R) y la acreditación de excelencia “María de Maeztu” 2018-2022 (MDM-2017-0714). ARU fue financiada por el programa de becas predoctorales (2016) de la Fundación Tatiana Guzman el Bueno

On correctors for spectral problems in the homogenization of Robin boundary conditions with very large parameters

We obtain estimates for convergence rates of the eigenelements (λ", u") for the Laplace operator in a domain ⊂ R3 periodically perforated along a plane γ = ∩ {x1 = 0}. The boundary conditions are of the Dirichlet type on ∂ and of the Robin type, involving a large parameter O(ε− ), on the boundary of the cavities. The small parameter ε denotes the period while the size of each cavity is O(ε ). Here we consider the most significant case where α = κ = 2

Boosting the visible-light photoactivity of Bi2WO6 using acidic carbon additives

We have explored the role of the physicohemical properties of carbon materials as additives to bismuth tungstate on its structure, optical properties, and photocatalytic activity for the degradation of rhodamine B under visible light. For this purpose, C/Bi2WO6 hybrid composites were prepared following two different routes: (i) physical mixture of the catalyst components, and (ii) one-pot hydrothermal synthesis of the semiconductor in the presence of the carbon additive. Three carbons with different properties were selected as additives: biomass-derived activated carbon, carbon nanotubes and carbon spheres obtained from polysaccharides. Data has shown the outstanding role of the acidic/basic nature of the carbon additive, and of the synthetic method on the photocatalytic performance of the resulting composites. For a given additive, the degradation rate of RhB is greatly improved for the catalysts prepared through a one-step hydrothermal synthesis, where there is low shielding effect of the carbon matrix. Carbon additives of acidic nature boost the surface acidity of the hybrid photocatalyst, thereby enhancing the photodegradation of RhB under visible light via a coupled mechanism (photosensitization, semiconductor photocatalysis and carbon-photon mediated reactions).The authors thank the financial support of MINECO (grants CTM2011/23378 and CTQ2011/26617) and PCTI Asturias (Fondos Feder 2007-2013, grant PC10-002). RJC thanks PCTI Asturias for her Severo Ochoa fellowshipPeer reviewe

Influencia de la presencia de compuestos superficiales de P sobre la funcionalización de carbones activos con HNO3

La funcionalización con ácido nítrico es un método ampliamente estudiado para la incorporación de grupos funcionales de oxígeno en la superficie de carbones activos, tales como grupos carboxilos, anhídridos, lactonas y fenoles. Sin embargo, también incorpora, en menor medida, grupos funcionales nitrogenados. Estos grupos funcionales de N son capaces de mejorar las propiedades de adsorción y/o catalíticas de diferentes carbones activos. Por otro lado, la activación química con ácido fosfórico produce carbones activos con una cantidad importante de grupos superficiales de fósforo de gran estabilidad, que les confiere una elevada resistencia a la oxidación y acidez, que los hace muy interesantes en diferentes aplicaciones catalíticas. En este trabajo se va a estudiar la influencia de la presencia de estos grupos de fósforo en la funcionalización de carbones activos con ácido nítrico.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A logic-algebraic tool for reasoning with Knowledge-Based Systems

A detailed exposition of foundations of a logic-algebraic model for reasoning with knowledge bases speci ed by propositional (Boolean) logic is presented. The model is conceived from the logical translation of usual derivatives on polynomials (on residue rings) which is used to design a new inference rule of algebro-geometric inspiration. Soundness and (refutational) completeness of the rule are proved. Some applications of the tools introduced in the paper are shown.Ministerio de Economía y Competitividad TIN2013-41086-

Extending Attribute Exploration by Means of Boolean Derivatives

We present a translation of problems of Formal Context Analysis into ideals problems in F2[x] through the Boolean derivatives. The Boolean derivatives are introduced as a kind of operators on propositional formulas which provide a complete calculus. They are useful to refine stem basis as well as for extending attribute exploration