On the Utility of the Inverse Gamma Distribution in Modeling Composite Fading Channels

We introduce a general approach to characterize composite fading models based on inverse gamma (IG) shadowing. We first determine to what extent the IG distribution is an adequate choice for modeling shadow fading, by means of a comprehensive test with field measurements and other distributions conventionally used for this purpose. Then, we prove that the probability density function and cumulative density function of any IG-based composite fading model are directly expressed in terms of a Laplace-domain statistic of the underlying fast fading model, and in some relevant cases, as a mixture of well-known state-of-the-art distributions. We exemplify our approach by presenting a composite IG/two-wave with diffuse power fading model, for which its statistical characterization is directly attained in a simple form.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Analysis of institutional effectiveness to floods in Totana´s town (Murcia)

Las herramientas de ordenación territorial constituyen el primer sistema defensivo ante los riesgos de inundación con menor impacto sobre el entorno y coste económico para salvaguardar la integridad de las personas. Con el paso del tiempo, se ha producido un progresivo incremento de la consideración de los riegos naturales, en especial los de inundación, como un criterio determinante de cara a la futura asignación de usos del suelo. La reciente inclusión de estrictos condicionantes relacionados con la prevención de riesgos naturales en diversas normativas sectoriales, así como de herramientas de simulación capaces de predecir los efectos de los mismos, representan el nuevo estado tendencial basado en el fomento de mecanismos pasivos de prevención antes que estructurales. Dentro del entramado de administraciones públicas encargadas de regular la ordenación territorial, los municipios, debido a su condición de instituciones que están en contacto directo con el territorio, constituyen el principal protagonista capaz de imbricar la ordenación territorial con la prevención de riesgos, motivo por el que se ha pretendido valorar en el presente trabajo el papel realizado por el consistorio de Totana, caso particular que guarda similitudes en todo el territorio nacional.The spatial planning tools are the first defense system against floods with less environment impact and lowest cost to safeguard the integrity of people. Over time, the natural hazards have been considered, specially floods, like a determinant standard for the future land-use planning. Recently, the apparition of related conditions with the prevention of natural hazards in various sectoral laws, also simulations tools capable of predicting their effects, are the new paradigm based on passive prevention mechanisms before the structural responses. Inside the different public administration responsible spatial planning, the municipals institutions, because they are the organism who are in direct contact with territory, they are the main character able to imbricate the spatial planning with the risk prevention, reason because the paper of the Totana’s hall town has been evaluated in this work, particular case but with similarities in all the Spanish territory

Testing for linear and quadratic effects between price adaptation and export performance: The impact of values and perceptions

Managerial perceptions are essential in explaining strategic decisions. It is, therefore, surprising that despite the number of studies that have examined the impact of managerial characteristics in exporting, little research has been reported in the export literature that investigates the importance of managers' perceptions on strategic decisions and resultant performance outcomes. To address this gap in the literature, the authors examine the key determinants of managers' psychic distance as well as its influence on international pricing decisions, and this in turn, on the export performance of SMEs. We also examine the quadratic effects of price adaptation on export performance. This is particularly relevant since price adaptation and export performance have been assumed in the literature to have a linear relationship. The results show that managers' perceptions have a significant impact on pricing decisions and resultant performance outcomes. Our findings also indicate that price adaptation has an inverted U-shaped relationship with export performance

Model ensembles of ecosystem services fill global certainty and capacity gaps

UK Research & Innovation (UKRI) NE/W005050/1 NE/T00391X/1 ES/R009279/1 ES/T007877/1 ES/V004077/1 ES/R006865/1National Science Foundation (NSF) NSF - Office of the Director (OD) 08695Next Generation European Union fundsUKCEHSpanish Government DGE-213989

New methodology for calculating damage variables evolution in Plastic Damage Model for RC structures

The behavior of reinforced concrete (RC) structures under severe demands, as strong ground motions, is highly complex; this is mainly due to joint operation of concrete and steel, with several coupled failure modes. Furthermore, given the increasing awareness and concern for the important seismic worldwide risk, new developments have arisen in earthquake engineering. Nonetheless, simplified numerical models are widely used (given their moderate computational cost), and many developments rely mainly on them. The authors have started a long-term research whose final objective is to provide, by using advanced numerical models, solid basis for these developments. Those models are based on continuum mechanics, and consider Plastic Damage Model to simulate concrete behavior. Within this context, this paper presents a new methodology to calculate damage variables evolution; the proposed approach is based in the Lubliner/Lee/Fenves formulation and provides closed-form expressions of the compressive and tensile damage variables in terms of the corresponding strains. This methodology does not require calibration with experimental results and incorporates a strategy to avoid mesh-sensitivity. A particular algorithm, suitable for implementation in Abaqus, is described. Mesh-insensitivity is validated in a simple tension example. Accuracy and reliability are verified by simulating a cyclic experiment on a plain concrete specimen. Two laboratory experiments consisting in pushing until failure two 2-D RC frames are simulated with the proposed approach to investigate its ability to reproduce actual monotonic behavior of RC structures; the obtained results are also compared with the aforementioned simplified models that are commonly employed in earthquake engineering.Postprint (published version

Information and communication technology (ICT) and basic competencies education

Resumen basado en el de la publicaciónSe analizan las nuevas competencias básicas en relación con las nuevas tecnologías. Ante la nueva sociedad de la información y las TIC el sistema educativo tiene que dar respuesta a las nuevas demandas de la población para satisfacer sus necesidades. Un análisis cronológico acerca a la necesidad de definir unas competencias básicas que debe poseer todo ciudadano. El papel de las TIC será crucial en el logro de la competencia digital, dentro de las competencias básicas que debe poseer todo ciudadano, para facilitar el que pueda ejercer sus derechos y deberes con plenitud, acordes con la sociedad cambiante a la que han de ir constantemente adaptándose, fruto del impulso de las nuevas tecnologías dominantes, las Tecnologías de la Información y la Comunicación (TIC).AndalucíaES

Performance analysis of MIMO-OFDM systems using complex Gaussian quadratic forms

En este trabajo se proponen aportaciones originales para el análisis de prestaciones en sistemas multiantena con múltiples portadoras, mediante el desarrollo de nuevas técnicas matemáticas para el cálculo de probabilidades de error. Así, ha sido posible analizar el efecto de no idealidades (estimación de canal imperfecta, offset de continua, desbalanceo I/Q…) en las prestaciones de sistemas de comunicaciones móviles e inalámbricas

Are Floods Becoming a More Expensive Hazard? A Damages Review of the Southeastern Spanish Coast (1996–2016).

Over the last few decades, an increasing economic and social flooding damages trend has been recorded worldwide. Although this situation was initially associated with climate change, recently different institutions and scientific papers have related this trend to two main reasons: (i) a human population increase and (ii) the number of assets located in floodable areas. In this regard, this paper analyses evolutions in flood damages and their causes in a Mediterranean area, the provinces of Alicante and Murcia, between 1996 and 2016. The duration of this period, from a flood risk management policy point of view, is very important because it encompasses one of the most important legislative periods at a national and European level. As a main result, this paper establishes a temporal and spatial pattern related to increases in flood damages and their main influence on coastal areas, respectively, due to certain economic, spatial and temporal factors. As a conclusion, these trends demonstrate the inefficiency of flood risk management policies, especially those connected with spatial planning.Partial funding for open access charge: Universidad de Málag

Assessing habitat diversity and potential areas of similarity across protected areas globally

Biophysical characterization analyses of protected areas (PA) that provide information on their ecological values and potential areas with similar characteristics are needed to make informed PA network planning and management decisions. This study combines and further develops methodologies that use remote sensing and modelling to identify habitat functional types in PAs and map similar areas at the ecoregion level. The study also develops new terrestrial habitat diversity and irreplaceability indices at habitat and PA scale that allow the comparison and ranking of PAs in terms of biophysical gradients and singular environmental conditions. Six PAs were selected to highlight and discuss the results of the proposed methodology. Both individual and composite indices should be considered when trying to compare PAs to understand the overall complexity and ecological values of each PA. Results can inform planning and management of individual and protected area networks as well as identify new areas for conservation. The information provided by the model about similar habitats outside protected areas can also help assess their representativeness and support studies to strengthen ecological connectivity. Besides systematic comparisons, detailed assessments of protected areas can also be performed using medium and high-resolution input variables. This is especially relevant for protected areas in developing countries where undertaking fieldwork is very difficult and the budget devoted to conservation is limited.European Commission European Commission Joint Research CentreBiodi- versity and Protected Areas Management (BIOPAMA) programme, an initiative of the African, Caribbean and Pacific (ACP) Group of StatesMarie Curie Actions CT-EX2020D381533-101Spanish Ministry of Universities and Next Generation European Union fund

The geometric Cauchy problem for the hyperbolic Hessian one equation

We solve the problem of finding all indefinite improper affine spheres passing through a given regular curve of R3R3 with a prescribed affine co-normal vector field along this curve. We prove the problem is well-posed when the initial data are non-characteristic and show that uniqueness of the solution can fail at characteristic directions. As application we classify the indefinite improper affine spheres admitting a geodesic planar curve.Ministerio de Educación y Ciencia Grant No. MTM2013-43970-P and Junta de Andalucía Grant No. FQM-325