6,338 research outputs found
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 AndalucÃa Tech
A Robust Localization System for Inspection Robots in Sewer Networks â€
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 turÃstico
Con este estudio pretendemos observar la presencia de investigaciones en finanzas
corporativas aplicadas al turismo en el perÃodo 1995-2012. Se ha utilizado la base de datos
Scopus para revistas turÃsticas indexadas en el Journal Citacion Reports, y el gestor
bibliográfico Mendeley para gestionar los resultados. Se han seleccionado 121 artÃculos
con contenido básicamente relacionado con finanzas de empresa. Los resultados revelan
que la tipologÃa de investigación mayoritariamente empleada ha sido la empÃrica; 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 turÃstico emergente: campiña turÃstica sevillana
En el presente artÃculo intentamos mostrar un modelo de dinamización de La Campiña
TurÃstica Sevillana. Para ello, comenzaremos con la creación y justificación del destino
turÃstico, diseñaremos el producto y lo orientaremos hacia la demanda y segmentos
turÃsticos 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 turÃstico sostenible y de calidad, que ha
contribuido a mejorar la calidad de vida de su sociedad. La clave turÃstica de este
destino está en la diversidad histórica y paisajÃstica que la caracteriza.
En estos momentos, Campiña TurÃstica 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 turÃstico emergente Campiña TurÃstica, y dinamizarlo
cumpliendo todos los requisitos vigentes en la normativa en materia turÃstica, 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 TurÃstica 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 turÃstico
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 turÃstico. 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 especÃficas
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 ArqueologÃa de la Arquitectura
A propósito del centenario del 711. Apuntes sobre método de la ArqueologÃa de la Arquitectur
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