Performance variability in basketball players with intellectual impairment: Ankara World Championships 2013 analysis

The aim of the present study was to identify performance variability in basketball for players with intellectual impairment (II) and to compare it with able-bodied (AB) players. Official game statistics from the 13 games played in the Ankara World II-Basketball Championships (2013) were gathered and descriptive data, variability coefficient (VC), maximum scores and its Z-score were calculated from those players who participated at least 10 minutes per game (N = 46; guards = 10, forwards = 21, centers = 15). Results indicated higher performance variability and lower efficiency in shooting percentages and turnovers in II-players comparing with studies in ABplayers. Differences found between game positions indicated similar roles of guards, forwards and centers in II and AB-players. These findings are relevant to understand how II impact on basketball performance, which is a necessary step to develop specific eligibility systems in II-basketball according to the guidelines of the International Paralympic Committee.

Analysis and design of reconfigurable multimode multiport microstrip antennas for mimo systems and diversity schemes

Las comunicaciones inalámbricas han transformado profundamente la forma en la que la gente se comunica en el día a día y es, sin lugar a dudas, una de las tecnologías de nuestro tiempo que más rápidamente evoluciona. Este rápido crecimiento implica retos enormes en la tecnología subyacente, debido y entre otros motivos, a la gran demanda de capacidad de los nuevos servicios inalámbricos. Los sistemas Multiple Input Multiple Output (MIMO) han despertado mucho interés como medio de mejorar el rendimiento global del sistema, satisfaciendo de este modo y en cierta medida los nuevo requisitos exigidos. De hecho, el papel relevante de esta tecnología en los actuales esfuerzos de estandarización internacionales pone de manifiesto esta utilidad. Los sistemas MIMO sacan provecho de los grados de libertad espaciales, disponibles a través del entorno multitrayecto, para mejorar el rendimiento de la comunicación con una destacable eficiencia espectral. Con el fin de alcanzar esta mejora en el rendimiento, la diversidad espacial y por diagrama han sido empleadas tradicionalmente para reducir la correlación entre los elementos radiantes, ya que una correlación baja es condición necesaria, si bien no suficiente, para dicha mejora. Tomando como referencia, o punto de partida, las técnicas empleadas para obtener diversidad por diagrama, esta tesis doctoral surge de la búsqueda de la obtención de diversidad por diagrama y/o multiplexación espacial a través del comportamiento multimodal de la antena microstrip, proponiendo para ello un modelo cuasi analítico original para el análisis y diseño de antenas microstrip multipuerto, multimodo y reconfigurables. Este novedoso enfoque en este campo, en vez de recurrir a simulaciones de onda completa por medio de herramientas comerciales tal y como se emplea en las publicaciones existentes, reduce significativamente el esfuerzo global de análisis y diseño, en este último caso por medio de guías de diseño generales. Con el fin de lograr el objetivo planteado y después de una revisión de los principales conceptos de los sistemas MIMO que se emplearán más adelante, se fija la atención en encontrar, implementar y verificar la corrección y exactitud de un modelo analítico que sirva de base sobre la cual añadir las mejoras necesarias para obtener las características buscadas del modelo cuasi analítico propuesto. Posteriormente y partiendo del modelo analítico base seleccionado, se exploran en profundidad y en diferentes entornos multitrayecto, las posibilidades en cuanto a rendimiento se refiere de diversidad por diagrama y multiplexación espacial, proporcionadas por el comportamiento multimodal de las antenas parche microstrip sin cargar. Puesto que cada modo de la cavidad tiene su propia frecuencia de resonancia, es necesario encontrar formas de desplazar la frecuencia de resonancia de cada modo empleado para ubicarlas en la misma banda de frecuencia, manteniendo cada modo al mismo tiempo tan independiente como sea posible. Este objetivo puede lograrse cargando adecuadamente la cavidad con cargas reactivas, o alterando la geometría del parche radiante. Por consiguiente, la atención en este punto se fija en el diseño, implementación y verificación de un modelo cuasi analítico para el análisis de antenas parche microstrip multipuerto, multimodo y cargadas que permita llevar a cabo la tarea indicada, el cuál es una de las contribuciones principales de esta tesis doctoral. Finalmente y basándose en el conocimiento adquirido a través del modelo cuasi analítico, se proporcionan y aplican guías generales para el diseño de antenas microstrip multipuerto, multimodo y reconfigurables para sistemas MIMO, con el fin de mejorar su diversidad por diagrama y/o su capacidad por medio del comportamiento multimodal de las antenas parche microstrip. Se debe destacar que el trabajo presentado en esta tesis doctoral ha dado lugar a una publicación en una revista técnica internacional de un alto factor de impacto. De igual manera, el trabajo también ha sido presentado en algunas de las más importantes conferencias internacionales en el ámbito de las antenas ABSTRACT Wireless communications have deeply transformed the way people communicate on daily basis and it is undoubtedly one of the most rapidly evolving technologies of our time. This fast growing behaviour involves huge challenges on the bearing technology, due to and among others reasons, the high demanding capacity of new wireless services. MIMO systems have given rise to considerable interest as a means to enhance the overall system performance, thus satisfying somehow the new demanding requirements. Indeed, the significant role of this technology on current international standardization efforts, highlights this usefulness. MIMO systems make profit from the spatial degrees of freedom available through the multipath scenario to improve the communication performance with a remarkable spectral efficiency. In order to achieve this performance improvement, spatial and pattern diversity have been traditionally used to decrease the correlation between antenna elements, as low correlation is a necessary but not sufficient condition. Taking as a reference, or starting point, the techniques used to achieve pattern diversity, this Philosophiae Doctor (Ph.D.) arises from the pursuit of obtaining pattern diversity and/or spatial multiplexing capabilities through the multimode microstrip behaviour, thus proposing a novel quasi analytical model for the analysis and design of reconfigurable multimode multiport microstrip antennas. This innovative approach on this field, instead of resorting to full-wave simulations through commercial tools as done in the available publications, significantly reduces the overall analysis and design effort, in this last case through comprehensive design guidelines. In order to achieve this goal and after a review of the main concepts of MIMO systems which will be followed used, the spotlight is fixed on finding, implementing and verifying the correctness and accuracy of a base quasi analytical model over which add the necessary enhancements to obtain the sought features of the quasi analytical model proposed. Afterwards and starting from the base quasi analytical model selected, the pattern diversity and spatial multiplexing performance capabilities provided by the multimode behaviour of unloaded microstrip patch antennas under different multipath environments are fully explored. As each cavity mode has its own resonant frequency, it is required to find ways to displace the resonant frequency of each used mode to place them at the same frequency band while keeping each mode as independent as possible. This objective can be accomplished with an appropriate loading of the cavity with reactive loads, or through the alteration of the geometry of the radiation patch. Thus, the focus is set at this point on the design, implementation and verification of a quasi analytical model for the analysis of loaded multimode multiport microstrip patch antennas to carry out the aforementioned task, which is one of the main contributions of this Ph.D. Finally and based on the knowledge acquired through the quasi analytical model, comprehensive guidelines to design reconfigurable multimode MIMO microstrip antennas to improve the spatial multiplexing and/or diversity system performance by means of the multimode microstrip patch antenna behaviour are given and applied. It shall be highlighted that the work presented in this Ph.D. has given rise to a publication in an international technical journal of high impact factor. Moreover, the work has also been presented at some of the most important international conferences in antenna area.

Fuel poverty analysis in three spanish autonomous regions. Some retrofitting policy considerations

A person is to be regarded as living ‘in fuel poverty’ if he is a member of a household living on a lower income in a home which cannot be kept warm at a reasonable cost. This situation is mainly triggered by three factors: low household income, lack of energy efficiency and high energy invoices. Some European countries have already made some advantages towards officially defining fuel poverty in their countries. Nevertheless, in Spain only some research has been done and an official definition of the term is yet to come. This research explores the relation among households’ income, energy expenditure and housing stock in three autonomous regions in Spain in order to evaluate the housing stock of the fuel poor as well as to identify those households more in need. The results of the research allow establishing energy retrofitting priorities of existing housing stock as well as identifying current retrofitting policies limitations on order to tackle fuel poverty.

Food market analysis: a case study of the Glocal methodology in the Dominican Republic

The present paper provides an insight into the food value chain of three specific sectors (fruit and vegetables, poultry and rice) in the Dominican Republic. The Glocal methodology used for the study combines a global view with local conditions and thus it can be applied to food markets. Each of these food chains is analyzed by following traditional industrial organization theory, based on structure, conduct and performance. Regarding the specific case of the Dominican Republic, different sources of information are used to analyze the weaknesses of the studied chains, including direct interviews. The food value chains of fruit and vegetables, poultry and rice in the Dominican Republic show a lack of structure and they are undergoing changes; however, they also have great opportunities to improve efficiency by making some changes.

Analysis by finite element calculations of light scattering in laser-textured AZO films for PV thin-film solar cells

In the thin-film photovoltaic industry, to achieve a high light scattering in one or more of the cell interfaces is one of the strategies that allow an enhancement of light absorption inside the cell and, therefore, a better device behavior and efficiency. Although chemical etching is the standard method to texture surfaces for that scattering improvement, laser light has shown as a new way for texturizing different materials, maintaining a good control of the final topography with a unique, clean, and quite precise process. In this work AZO films with different texture parameters are fabricated. The typical parameters used to characterize them, as the root mean square roughness or the haze factor, are discussed and, for deeper understanding of the scattering mechanisms, the light behavior in the films is simulated using a finite element method code. This method gives information about the light intensity in each point of the system, allowing the precise characterization of the scattering behavior near the film surface, and it can be used as well to calculate a simulated haze factor that can be compared with experimental measurements. A discussion of the validation of the numerical code, based in a comprehensive comparison with experimental data is included.

Analysis of the behavior of multijunction solar cells under high irradiance Gaussian light profiles showing chromatic aberration with emphasis on tunnel junction performance

In this work, we explain the behavior of multijunction solar cells under non-uniform (spatially and in spectral content) light profiles in general and in particular when Gaussian light profiles cause a photo-generated current density, which exceeds locally the peak current density of the tunnel junction. We have analyzed the implications on the tunnel junction's limitation, that is, in the loss of efficiency due to the appearance of a dip in the I–V curve. For that, we have carried out simulations with our three-dimensional distributed model for multijunction solar cells, which contemplates a full description of the tunnel junction and also takes into account the lateral resistances in the tunnel junction. The main findings are that the current density photo-generated spreads out through the lateral resistances of the device, mainly through the tunnel junction layers and the back contact. Therefore, under non-uniform light profiles these resistances are determinant not only to avoid the tunnel junction's limitation but also for mitigating losses in the fill factor. Therefore, taking into account these lateral resistances could be the key for jointly optimizing the concentrator photovoltaic system (concentrator optics, front grid layout and semiconductor structure)

Aerodynamic parametric analysis of an unconventional joined-wing aircraft configuration

In this paper, the experimental results of an unconventional joined-wing aircraft configuration are presented. The test model uses two different wings, forward and rear, both joined in tandem and forming diamond shapes both in plant and front views. The wings are joined in such a way that it is possible to change the rear wing dihedral angle values and the rear wing sweep angle values in 25 different positions that modify the relative distance and the relative height between the wings. To measure the system aerodynamic coefficients itis necessary to perform wind tunnel tests. The datapresented corresponds to the lift, drag and induced drag aerodynamic coefficients, as well as the aerodynamic efficiency and the parameter for minimum required power, from the calculated values of the lift and drag time series measured by a 6-axis force and torque sensor. The results show the influence on the aerodynamic coefficients of the rear wing sweep and dihedral angles parameters. As a main result, it can be concluded that, in general terms, the lift and induced drag aerodynamic coefficients values decrease as both the distance and height between the wings increase, on the other hand, the total drag aerodynamic coefficient decreases if the distance between the wings increases, but nevertheless shows a slight tendency to increase if the height of the rear wing increases, whereas the aerodynamic efficiency and the parameter for minimum required power increase if the distance between the wings increases