Diversity in mobile communications for blind detection of block-coded modulations

Spatial, temporal, and frequency diversity structures are analyzed to address the blind equalization problem in the presence of time-variant frequency selective channels. The aim of the paper is to present equalization schemes useful in front of fast changing channel responses. The best solution is a deterministic blind criterion that allows direct channel equalization and symbol detection. The main contribution of this paper is to present deterministic blind equalization schemes in CDMA systems (frequency diversity) to reduce the impact of the time-variant frequency selective channel.Peer ReviewedPostprint (published version

REDEPEND-REACT: an architecture analysis tool

The i* approach includes the construction of strategic dependency models (SD) developed to model information systems that can be applied in a wide variety of contexts. We are interested in the formulation of metrics over i* models to be used in components system architectures analysis. These metrics are defined to analyse the models with respect to some properties that are interesting for the system being modelled, such as security, efficiency or accuracy. Metrics are defined in terms of the actors and dependencies of the models and the results of their evaluation are used to inform multiple component selection. As the definition and evaluation of the property metrics are cumbersome activities, the need of tool support arises. Thus, we have enlarged REDEPEND, a Microsoft Visio plug-in that graphically models system goals using the i* formalism, to support the definition and evaluation of architectural properties obtaining the REDEPEND-REACT prototype.Peer ReviewedPostprint (published version

A goal-based round-trip method for system development

In most cases information system development can be seen as an exercise of business process reengineering, either because it automates some human-based processes or because a legacy system is going to be replaced. From this point of view, we can say that the specification of the system-to-be goes from the observation and analysis of the current system to the specification of the system-to-be, going through the construction and evaluation of alternatives. Goal-oriented models are a valuable formalism to support the strategic analysis of the current process. In this paper, we propose a method supporting that round-trip engineering process, focusing in the prescriptive construction of strategic i* models and the systematic generation of alternatives. Several requirements engineering techniques are used in order to model the existing process, which allow a reliable generation and evaluation of alternatives as well as the reuse of strategic knowledge for information system development.Peer ReviewedPostprint (author's final draft

Urban cartographies: the graphic representation of the conflict in public spaces

[EN] Contemporaneousness has represented, in different formats, situations that are socially unstable and capable of transforming urban public spaces. The 20th century, since its beginnings, has been proof of that, generating documents of irregular technical quality but of undoubted interest. Those who have elaborated them have participated, sometimes individually and in some other times as a collective, creating planimetries that contribute to the understanding of conflictive situations in present-day Europe. This context has brought about a renewed reading and a generation of maps that reflect these sociopolitical upheavals. Faced with plans of a precise nature and with an eagerness to record reality, in the face of propositional documents that reflect the planned evolution of populations and territories, we present some cartographies that, simultaneously, contemplate unforeseen transformations of the existing city, ephemeral, while establishing future developments of uncertain materialization. It is a unique set of documents that concentrate layers of cartographic and social information transcendent for our time.[ES] La contemporaneidad ha representado, en diferentes formatos, situaciones socialmente inestables y capaces de transformar los espacios públicos urbanos. El siglo xxi, en sus inicios, ha dado muestras de lo anterior, generando documentos de calidad técnica irregular pero de indudable interés. Quienes los han elaborado han participado, en ocasiones de manera individual y en otras como colectivo, creando unas planimetrías que contribuyen al entendimiento de situaciones conflictivas en la Europa actual. Este contexto ha hecho que se produzca una renovada lectura y generación de mapas que reflejan estas convulsiones sociopolíticas. Frente a planos de carácter preciso y con afán de registro de la realidad, frente a documentos propositivos que recogen la evolución planificada en el tiempo de poblaciones y territorios, presentamos unas cartografías que, simultáneamente, contemplan transformaciones imprevistas de la ciudad existente, de carácter efímero, al tiempo que establecen desarrollos futuros de incierta materialización. Es un conjunto singular de documentos que concentran capas de información cartográfica y social trascendentes para nuestra época.Moral Andrés, F.; Merino Gómez, E. (2018). Cartografías urbanas: la representación gráfica del conflicto en los espacios públicos. EGA. Revista de Expresión Gráfica Arquitectónica. 23(32):262-273. doi:10.4995/ega.2018.7973SWORD2622732332Debord, G., 2010. La sociedad del espectáculo. Valencia: Pre-textos.Perniola, M. 2010. Los situacionistas. Historia crítica de la última vanguardia del siglo xx. Madrid: Acuarela - Machado GrupoStamps, L., Stokvis, W. et al. 2015. Constant. Nueva Babilonia. Madrid: Museo Nacional Centro de Arte Reina Sofí

Theoretical investigation of the lattice thermal conductivities of II-IV-V2 pnictide semiconductors

Ternary pnictides semiconductors with II-IV-V2 stoichiometry hold potential as cost effective thermoelectric materials with suitable electronic transport properties, but their lattice thermal conductivities ($\kappa$) are typically too high. Gaining insight into their vibrational properties is therefore crucial to finding strategies to reduce $\kappa$ and achieve improved thermoelectric performance. We present a theoretical exploration of the lattice thermal conductivities for a set of pnictide semiconductors with ABX2 composition (A = Zn, Cd; B = Si, Ge, Sn; and X = P, As), using machine-learning based regression algorithms to extract force constants from a reduced number of density functional theory simulations, and then solving the Boltzmann transport equation for phonons. Our results align well available experimental data, decreasing the mean absolute error by ~3 Wm-1K-1 with respect to the best previous set of theoretical predictions. Zn-based ternary pnictides have, on average, more than double the thermal conductivity of the Cd-based compounds. Anisotropic behaviour increases with the mass difference between A and B cations, but while the nature of the anion does not affect the structural anisotropy, the thermal conductivity anisotropy is typically higher for arsenides than for phosphides. We identify compounds, like CdGeAs2, for which nanostructuring to an affordable range of particle sizes could lead to values low enough for thermoelectric applications.Comment: 24 pages, 8 figure

Catalizadores de Ni-Co/Al2O3 obtenidos por Combustión de Matriz de Urea espontánea y controlada para producir H2 por APR de Glicerol

The aim is to improve the interaction and dispersion of Ni/Co in catalysts supported on γ-Al2O3 by controlling the temperature in the preparation by the urea matrix combustion method (CCMU). The resulting samples are used to obtain H2 by aqueous phase reforming (APR) of glycerol. Ni and Co nitrates are co-impregnated with urea, dried and fixed by heating with different temperature ramps (R1, R5 and R10) to obtain 1.5% Ni and 4.5% Co. The physicochemical properties are characterized by N2 sortometry and CO chemisorption. Its behavior is analyzed in APR of glycerol with 0.5 g of catalyst reduced at 500 ºC. Production and selectivity to H2, reaction stability and deactivation by coke are analyzed by temperature programmed oxidation (TPO). The CCMU-R10 catalyst shows improved H2 performance and greater metallic dispersion compared to the same catalyst prepared by spontaneous combustion, without temperature control, CMU. Controlling the combustion of urea improves the Ni/Co interaction, increasing the yield to H2 by 74%, with equal selectivity to H2 and CH4 and reducing the coke accumulated in the same period in APR of glycerol in the selected reaction conditions by 21%.Se busca mejorar la interacción y dispersión de Ni/Co en catalizadores soportados en γ-Al2O3 controlando la temperatura en la preparación por el método de combustión de matriz de urea (CCMU). Las muestras resultantes se utilizan para obtener H2 por reformado en fase acuosa (APR) de glicerol. Nitratos de Ni y Co son co-impregnados con urea, secados y fijados por calentamiento a diferentes rampas de temperatura (R1, R5 y R10) para obtener 1,5% Ni y 4,5% Co. Las propiedades fisicoquímicas son caracterizadas por sortometría de N2 y quimisorción de CO. Su comportamiento se analiza en APR de glicerol con 0,5 g de catalizador reducido a 500 ºC. Se analiza producción y selectividad a H2, estabilidad en reacción y desactivación por coque, mediante oxidación a temperatura programada (TPO). El catalizador CCMU-R10 muestra un rendimiento a H2 mejorado y mayor dispersión metálica respecto al mismo catalizador preparado por combustión espontánea, sin control de temperatura, CMU. Controlando la combustión de la urea se mejora la interacción Ni/Co incrementándose un 74% el rendimiento a H2, con igual selectividad a H2 y CH4 y reduciendo un 21% el coque acumulado en igual período en APR de glicerol en las condiciones de reacción seleccionadas

ADC Quantization Requirements

In this document, we analyze the impact of the quantization at the input of the demultiplexer. The required number of bits of the Analog-to-Digital-Converter (ADC) is obtained, along with the corresponding quantization losses.Preprin

Harvest Strategies for an Ecosystem Approach to Fisheries Management in Western Mediterranean Demersal Fisheries

The serious overfishing of most Mediterranean stocks demands urgent reforms of the management measures aiming to guarantee the sustainability of resources, notably when compared with the improvement observed in other European areas. The new EU Common Fisheries Policy (CFP) constitutes an excellent opportunity to introduce the changes needed for such a reform. According to this CFP, all European fish stocks should be brought to a state where they can produce at MSY by 2020 at the latest. The CFP also establishes that the objective of sustainable exploitation should be achieved through multiannual plans (MAPs) adopted in consultation with relevant stakeholders having fisheries management interests such as fishermen, non-governmental organizations, and policy makers. Together with the MSY and MAP approaches, the new CFP contains several other measures, directed to guarantee the ecological and socio-economic sustainability of fisheries by means of the implementation of the ecosystem approach to fisheries management (EAFM). With this new perspective, the CFP wants to avoid past failures of fisheries management based on monospecific approaches. This study is a first step toward the application of the EAFM in the Balearic Islands by means of the development of a harvest strategy with defined objectives, targets, limits, and clear management control rules aimed at optimizing socioeconomic and ecological objectives in the framework of the new CFP. Different management scenarios designed to achieve that goal were modeled for the main demersal commercial fisheries from the study area, the bottom trawl, and small-scale fisheries. The work begins with a general description of those fisheries, their main fishing grounds, and assessments of the exploitation status of the main target stocks in order to establish the current situation. Secondly, alternative management scenarios to maximize catch and profits while considering societal objectives were evaluated by means of bio-economic models. Thirdly, management measures were provided based on the previous modeling and discussions with stakeholders. Finally, a monitoring scheme was outlined to assess the progresses of the proposed management actions. This work is intended to be a working example of co-management (fishers, policy-makers, and scientists) in the Mediterranean in the framework of the new EU CFPVersión del edito

Sobre el mapa: estrategias de gestión de la información en la cartografía actual

El mapa se ha transformado en el soporte ideal sobre el que gestionar múltiples las capas de información que afectan al territorio. Históricamente, las estrategias gráficas empleadas para la representación y comunicación de toda esa información, merece nuestra consideración en la medida en la que pueden extrapolarse estrategias proyectuales aplicables sobre el territorio. Tomando como punto de partida una serie de cartografías que, a lo largo de los años, han supuesto un avance en materia de comunicación gráfica, se hace un repaso de la contribución cultural que supone este soporte. Desde unos inicios que evidencian un tránsito desde el espacio topológico al de representación cartesiana, pasando por la búsqueda de herramientas de gestión gráfica de elementos cambiantes, así como la incorporación del Big Data en cartografías más próximas al diagrama que al mapa tradicional, podemos observar una necesaria confluencia de todos esos niveles de información. Todos estos recursos, sirven en la actualidad a los arquitectos y urbanistas, como punto de partida que permite no solo representar los aspectos más intangibles del proyecto, sino también explorar nuevas formas de comunicación multidimensional. En definitiva, nos otorga la capacidad de cartografiar no solo lo real, también lo imaginado

Sentinel-2 analysis of flooded areas: applied case study "La Safor wetland, Spain"

[EN] La Safor wetland is a representative coastal wetland in the Valencia Region (eastern Spain, Mediterranean Sea). This wetland is recognized at an international level as a Special Protection Area (SPAs) for birds and a Site of Community Importance (SCIs) (Habitats Directive, European Council Directive). The wetland is located on a detrital plain aquifer which in turn is fed by a karstic aquifer in the near limestone reliefs. The flooded surface is variable and depends on pluviometry among other factors. The objective of this study is to analyse the effects of the flooded surface on land uses by remote sensing and Airborne LiDAR data. Sentinel-2A images processed at level 1C were obtained from Copernicus. LiDAR data was used to detect the most vulnerable areas affected by floods. In the results, we analysed the impact of the maximum flooded surface on land uses. We propose several corrective actions on the drainage net based on our analysis. This methodology can be applied to other wetland areas of similar characteristics. The advantage is the high spatial resolution which makes the methodology suitable for small sized wetlands.Pena-Regueiro, J.; Sebastiá-Frasquet, M.; Aguilar-Maldonado, JA.; Estornell Cremades, J.; Sanchís Blay, JA.; Morell-Monzó, S.; Altur Grau, VJ. (2020). Sentinel-2 analysis of flooded areas: applied case study "La Safor wetland, Spain". WIT Transactions on Ecology and the Environment (Online). 242:63-70. https://doi.org/10.2495/WP200061S637024