Switching-Cell Arrays - An Alternative Design Approach in Power Conversion

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe conventional design of voltage-source power converters is based on a two-level half-bridge configuration and the selection of power devices designed to meet the full application specifications (voltage, current, etc.). This leads to the need to design and optimize a large number of different devices and their ancillary circuitry and prevents taking advantage from scale economies. This paper proposes a paradigm shift in the design of power converters through the use of a novel configurable device consisting on a matrix arrangement of highly-optimized switching cells at a single voltage class. Each switching cell consists of a controlled switch with antiparallel diode together with a self-powered gate driver. By properly interconnecting the switching cells, the switching cell array (SCA) can be configured as a multilevel active-clamped leg with different number of levels. Thus, the SCA presents adjustable voltage and current ratings, according to the selected configuration. For maximum compactness, the SCA can be conceived to be only configurable by the device manufacturer upon the customer needs. For minimum cost, it can also be conceived to be configurable by the customer, leading to field-configurable SCAs. Experimental results of a 6x3 field-configurable SCA are provided to illustrate and validate this design approach.Peer ReviewedPostprint (author's final draft

Archaeological remains from the siege of Madinat Basta (Baza, Spain), by the catholic monarchs in 1489

The Catholic Monarchs (Isabella I of Castile and Ferdinand II of Aragon) besieged the cities of the last Islamic kingdom on the Iberian Peninsula during the War of Granada (1482-1492), until surrender the capital of the Nasrid dynasty, Madinat Garnata and Madina Alhambra. The military campaigns were strategically programmed. A series of cities was chosen so that their fall would cause the surrender of a part of the territory, due to a domino effect. The capture of Madinat Basta (Baza), to the extreme North of the Nasrid kingdom, was seen as an easy target by the strategists of the Catholic Monarchs. However, the battle-hardened defence of the population and the special configuration and territorial layout of the city resulted in one of the hardest sieges of the campaign, lasting from mid-June to the beginning of December, 1489. To achieve this goal they adopted a strategy that Scipio Africanus the Younger had already developed in 133 B.C., when he surrounded the Celtiberian city of Numantia. Around Baza there are archaeological remains of different structures that can be linked to this conflict. In this communication we have analysed the fortification works that could have been built during the Christian siege of 1489, on the basis of the archaeological evidence and the historical written sources.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A Robust Localization System for Inspection Robots in Sewer Networks †

Sewers represent a very important infrastructure of cities whose state should be monitored periodically. However, the length of such infrastructure prevents sensor networks from being applicable. In this paper, we present a mobile platform (SIAR) designed to inspect the sewer network. It is capable of sensing gas concentrations and detecting failures in the network such as cracks and holes in the floor and walls or zones were the water is not flowing. These alarms should be precisely geo-localized to allow the operators performing the required correcting measures. To this end, this paper presents a robust localization system for global pose estimation on sewers. It makes use of prior information of the sewer network, including its topology, the different cross sections traversed and the position of some elements such as manholes. The system is based on a Monte Carlo Localization system that fuses wheel and RGB-D odometry for the prediction stage. The update step takes into account the sewer network topology for discarding wrong hypotheses. Additionally, the localization is further refined with novel updating steps proposed in this paper which are activated whenever a discrete element in the sewer network is detected or the relative orientation of the robot over the sewer gallery could be estimated. Each part of the system has been validated with real data obtained from the sewers of Barcelona. The whole system is able to obtain median localization errors in the order of one meter in all cases. Finally, the paper also includes comparisons with state-of-the-art Simultaneous Localization and Mapping (SLAM) systems that demonstrate the convenience of the approach.Unión Europea ECHORD ++ 601116Ministerio de Ciencia, Innovación y Universidades de España RTI2018-100847-B-C2

La presencia de las finanzas corporativas en revistas de ámbito turístico

Con este estudio pretendemos observar la presencia de investigaciones en finanzas corporativas aplicadas al turismo en el período 1995-2012. Se ha utilizado la base de datos Scopus para revistas turísticas indexadas en el Journal Citacion Reports, y el gestor bibliográfico Mendeley para gestionar los resultados. Se han seleccionado 121 artículos con contenido básicamente relacionado con finanzas de empresa. Los resultados revelan que la tipología de investigación mayoritariamente empleada ha sido la empírica; la temática de mayor interés son la gestión financiera de la empresa, la creación de valor, estructura de capital y decisiones de inversión. También destaca International Journal of Hospitality Management como la revista de mayor presencia financiera en la empresa.The purpose of this study is to observe the presence of corporate finance research applied to tourism during the 1995-2012 period. The Scopus database has been used for tourism journals indexed in Journal Citation Reports and the Mendeley reference manager was used to manage the results. One hundred and twenty-one articles were selected with basically financial content. The results reveal that in the majority of cases empirical research typology was used; the subject matter that aroused most interest was corporate finances and, within this, company financial management, value creation, capital structure and investment decisions. The International Journal of Hospitality Management also stands out as the journal with the greatest presence of finances

Creación, dinamización y puesta en valor del destino turístico emergente: campiña turística sevillana

En el presente artículo intentamos mostrar un modelo de dinamización de La Campiña Turística Sevillana. Para ello, comenzaremos con la creación y justificación del destino turístico, diseñaremos el producto y lo orientaremos hacia la demanda y segmentos turísticos adecuados. Ello está justificado en que esta área geográfica, en los últimos cinco años, ha apostado firmemente por la diversidad y el desarrollo integral del destino, con la vista puesta en un desarrollo turístico sostenible y de calidad, que ha contribuido a mejorar la calidad de vida de su sociedad. La clave turística de este destino está en la diversidad histórica y paisajística que la caracteriza. En estos momentos, Campiña Turística se encuentra en una situación favorable de cara al turismo potencial. Por ello, distintos organismos públicos como Prodetur, S.A., aúnan esfuerzos para unir siete localidades no pertenecientes a una organización territorial determinada, formar el destino turístico emergente Campiña Turística, y dinamizarlo cumpliendo todos los requisitos vigentes en la normativa en materia turística, dotándolo de todos los instrumentos necesarios para poder elevarlo hacia la excelencia.In this article we attempt to provide a dinamization model of the Tourism in the Sevillian Countryside (Campiña Turística Sevillana). To do this, we start with the creation and justification of the destination; we will design the product and demand- driven and appropriate tourist segments. This is justified in this geographic area, as in the last five years, is strongly committed to diversify and arrive at the integral development of destination, in order to reach a sustainable tourism development and quality, which has helped improve the quality of life of their society. The key of this tourist destination is the historic and scenic diversity that characterizes it. At present, Tourism in the Sevillian Countryside is in a good position facing the tourism potential. Therefore, various public bodies as Prodetur SA join forces to connect seven locations without territorial organization determined to form the emerging tourist destination Tourism in the Countryside, doing a dinamization, meeting all requirements in the tourism industry standards, and providing it with all the tools they need to raise it toward excellence

La oferta académica del nuevo grado en turismo en la EUEE de la Universidad de Sevilla y las necesidades formativas demandadas por el sector turístico

El trabajo que se presenta realiza un estudio comparativo entre la oferta académica del Grado en Turismo en la Escuela Universitaria de Estudios Empresariales de la Universidad de Sevilla, en fase de aprobación, y las necesidades formativas que demanda el sector turístico. Mediante una encuesta a entidades, empresas y corporaciones, con las que la EUEE mantiene acuerdos de práctica, se intenta detectar los puntos fuertes y débiles que la oferta formativa del Centro tiene para el sector profesional. Los resultados muestran que los módulos que desarrollan competencias transversales son más valorados que los que desarrollan competencias específicas modulares. Además, todas las materias del Grado tienen una valoración media o alta. Finalmente, los estudiantes realizan actividades de prácticas en empresa que poseen escaso nivel creativo y baja responsabilidad en la organización.This paper presents a comparative study between the offer of an academic Tourism degree at the Business School in the University of Seville, in the process of adoption and the training needs required by the tourism industry. Through a survey of institutions, companies and corporations, with which EUEE maintains placement agreements, we try to identify the strengths and weaknesses of the training Center for the professional sector. The results show that the modules that develop transversals skills are more valued than those that develop specific modules. In addition, all subjects have a medium or high assessment. Finally, students execute work placements that have little creativity and low-level of responsibility in the organization

VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties

We present and discuss the 2D kinematic properties of the ionized gas (Halpha) in a sample of 38 local (ultra) luminous infrared galaxies [(U)LIRGs] (31 LIRGs and 7 ULIRGs) observed with VIMOS at the VLT using integral field spectroscopy. This sample covers well the less studied LIRG luminosity range and includes isolated disks, interacting systems, and mergers. The majority of the galaxies have two main kinematically distinct components. One component (i.e., narrow or systemic) extends over the whole line-emitting region and is characterized by small to intermediate velocity dispersions (i.e., sigma from 30 to 160 km s^-1). It traces the overall velocity field. The second component (broad) has in general a larger velocity dispersion (up to 320 km s^-1), mainly found in the inner regions and generally blueshifted with respect to the systemic component. Most of the objects (76%) are dominated by rotation, more relevant in LIRGs than in ULIRGs. Isolated disks, interacting galaxies, and merging systems define a sequence of increasing mean velocity dispersion, and decreasing velocity field amplitude.The LIRGs classified as isolated disks have similar velocity amplitudes but larger mean velocity dispersions (44 vs. 24 km s^-1) than local spirals, implying a larger turbulence and thicker disks. Interacting systems and mergers have values closer to those of low velocity dispersion ellipticals/lenticular galaxies (E/SOs). The (U)LIRGs classified as mergers have kinematic properties similar to those shown by the Lyman break analogs (LBAs). The dynamical masses range from \sim 0.04 m* to 1.4 m* (i.e., m* = 1.4x10^{11} Msun), with ULIRGs (M{dyn} sim 0.5 +/- 0.2 m*) being more massive than LIRGs by, on average, a factor of about 2. The mass ratio of individual pre-coalescence galaxies is <2.5 for most of the systems, confirming that most (U)LIRG mergers involve sub-m* galaxies of similar mass.Comment: 66 pages, 5 figures plus 45 figures in App. A; accepted for publication in A&

A propósito del centenario del 711. Apuntes sobre método de la Arqueología de la Arquitectura

A propósito del centenario del 711. Apuntes sobre método de la Arqueología de la Arquitectur