198 research outputs found
Small area estimation of proportions under area-level compositional mixed models
[Abstract]: This paper introduces area-level compositional mixed models by applying transformations to a multivariate Fay–Herriot model. Small area estimators of the proportions of the categories of a classification variable are derived from the new model, and the corresponding mean squared errors are estimated by parametric bootstrap. Several simulation experiments designed to analyse the behaviour of the introduced estimators are carried out. An application to real data from the Spanish Labour Force Survey of Galicia (north-west of Spain), in the first quarter of 2017, is given. The target is the estimation of domain proportions of people in the four categories of the variable labour status: under 16 years, employed, unemployed and inactive.Supported by the Instituto Galego de Estatística, by the grants PGC2018-096840-B-I00 and MTM2017-82724-R of the Spanish Ministerio de Economía y Competitividad and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF.Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0
Small area estimation of expenditure means and ratios under a unit-level bivariate linear mixed model
This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Applied Statistics on 05 Aug 2020, available at: https://doi.org/10.1080/02664763.2020.1803809[Abstract]: Under a unit-level bivariate linear mixed model, this paper introduces small area predictors of expenditure means and ratios, and derives approximations and estimators of the corresponding mean squared errors. For the considered model, the REML estimation method is implemented. Several simulation experiments, designed to analyze the behavior of the introduced fitting algorithm, predictors and mean squared error estimators, are carried out. An application to real data from the Spanish household budget survey illustrates the behavior of the proposed statistical methodology. The target is the estimation of means of food and non-food household annual expenditures and of ratios of food household expenditures by Spanish provinces.Supported by the grants MTM2017-82724-R and PGC2018-096840-B-I00 of the Ministerio de Economía y Competitividad (MINECO) and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF.Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0
Comparación y validación de formulaciones aplicadas a cimentaciones monopilotadas en eólica marina
Las estructuras monopilotadas son la tipología de cimentación más común en eólica marina, con un porcentaje de centrales del 80 % en Europa, y con diámetros de hasta 8 metros.
La tendencia en las construcciones offshore futuras parece estar encaminada al desarrollo de este tipo de estructuras, con lo cual los monopilotes seguirán siendo la principal cimentación en eólica marina, quedando aun mucho margen de evolución en esta tipología y avanzando cada vez hacia mayores diámetros y profundidades.
Los objetivos perseguidos en la elaboración del trabajo están relacionados con el dimensionamiento de estas estructuras pilotadas. Para verificar si los modelos de cálculo de longitudes de monopilotes orientados a cimentaciones onshore pueden ser aplicadas en situaciones offshore. Además, se ha querido establecer una relación entre tipologías de suelo y longitudes de los pilotes
Small area estimation of average compositions under multivariate nested error regression models
[Abstract]: This paper investigates the small area estimation of population averages of unit-level compositional data. The new methodology transforms the compositions into vectors of Rm and assumes that the vectors follow a multivariate nested error regression model. Empirical best predictors of domain indicators are derived from the fitted model, and their mean squared errors are estimated by parametric bootstrap. The empirical analysis of the behavior of the introduced predictors is investigated by means of simulation experiments. An application to real data from the Spanish household budget survey is given. The target is to estimate the average of proportions of annual household expenditures on food, housing and others, by Spanish provinces.Generalitat Valenciana; Prometeo/2021/063Xunta de Galicia; ED431C 2020/14Xunta de Galicia; ED431G 2019/01Axencia Galega de Innovación; COV20/00604Supported by the Instituto Galego de Estatística, by the Grants PGC2018-096840-B-I00 and PID2020-113578RB-I00 of the Spanish Ministerio de Economía y Competitividad, by the Grant Prometeo/2021/063 of the Generalitat Valenciana, and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C 2020/14), and by GAIN (Galician Innovation Agency) and the Regional Ministry of Economy, Employment and Industry Grant COV20/00604 and Centro de Investigación del Sistema Universitario de Galicia ED431G 2019/01, all of them through the ERDF
Requerimientos portuarios para la operación y mantenimiento de parques eólicos Offshore. Selección de puertos
Las infraestructuras portuarias sirven a la industria
eólica offshore de numerosas maneras. Esta
industria, por sus particularidades, impone diversos
requerimientos a la infraestructura portuaria que
difieren según el puerto empleado en cada momento
de la vida útil del parque offshore (construcción u
operación y mantenimiento).
En línea con estos principios, se ha realizado un
estudio adaptado a las particularidades de los
puertos españoles para identificar cuáles son capaces
de llevar a cabo la operativa de operación y
mantenimiento de un parque eólico offshore.
Para ello, se han identificado las diferentes tareas de
mantenimiento de componentes y las instalaciones y
equipamiento necesarias para llevarlas a cabo, para
luego analizar los diferentes puertos del litoral
español con el objetivo de determinar de un modo
gráfico y sencillo qué puertos cumplen con los
condicionantes impuestos
Análisis de localización para la instalación de una central de aprovechamiento de energía undimotriz en la costa norte de España
Numerosos estudios han revelado que existe un gran
potencial energético en la costa norte de la Península
Ibérica gracias a que el Océano Atlántico baña este
territorio. Con el desarrollo e investigación de nuevas
tecnologías, se plantea la posibilidad de construir una
central de aprovechamiento undimotriz, que esté
integrada en uno de los diques de mayor entidad en
el norte de España, como son el dique de Punta
Langosteira (Puerto Exterior de A Coruña, Galicia), el
dique de Torres y Norte (Ampliación del Puerto de Gijón, Asturias) y el dique de Punta Lucero (Puerto de
Bilbao, País Vasco)
Bases para recuperação do centro histórico de Avis, Largo Cândido dos Reis
Nos dias de hoje deparamos com uma grave situação nos Centros Históricos e nos
Espaços Públicos em Portugal. Existe uma tendência para sua desertificação e
envelhecimento populacional, o que origina a sua degradação e desadequação. Esta
situação resulta dos Centros Históricos não conseguirem dar resposta às suas
necessidades inerentes ao atual modo de vida. Depararam-se com a realidade e ficaram
incapazes de acompanhar a evolução temporal, o que origina a sua deterioração e
desqualificação, quer no seu edificado quer no Espaço Público.
Atualmente, um novo protagonismo assume a necessidade de conservação e
revitalização dos nossos Centros Históricos, devolvendo-lhe assim todas as suas
qualidades. O Centro Histórico de Avis é mais uma vítima da incapacidade de acompanhar a
evolução temporal com o seu Espaço Público desadequado aos novos estilos de vida, não
favorecendo a segurança e conforto dos seus utilizadores com presença abusiva do
automóvel, o património edificado degradado e o mobiliário urbano desadequado, tudo
situações negativas que contribuem para a desvalorização do seu património.
Face ao exposto proponho-me, nesta dissertação, promover levantamentos e
estudos que possibilitem a recuperação e dinamização do Largo Cândidos dos Reis,
promovendo intervenção neste Espaço, devolvendo aos seus utilizadores uma qualidade e
conforto na sua utilização.in Portugal. A trend to desertification and an ageing population have constituted the
foundations for their deterioration and exhaustion. Such situation is the result of a lack of
solutions to answer to the people’s present time needs in terms of a city centre life should be.
This is the reality that was not thought in due time and that consequently, resulted in the
disqualification, of the already built area, as well as of the public places.
At the present time, the leading role should be on the necessity of preservation and
innovation of our historical urban city centres, restoring their quality.
The centre of Avis is another victim of the already stated incapacity of
appropriateness to the new cosmopolitan life styles, where people’s security and comfort
have been forgotten. The massive presence of automobiles, the degradation of the built
areas, the inappropriate street furniture have all led to its patrimony to be devalued. The
purpose of this research is to promote surveys and studies that can lead to the rehabilitation
and innovation of the Largo Cândido dos Reis encouraging intervention in the public space.Orientação: Vasco Maria Tavela de Santos Santos Pinheir
Comportamiento hidrodinámico y sensibilidad de los esquemas de diseño en estructuras de gravedad aplicadas a energías eólicas marinas
Las distintas tipologías estructurales empleadas en energías eólicas marinas dependen básicamente de la capacidad portante del terreno, las profundidades del emplazamiento, las características del parque y las afecciones a la costa, tanto a nivel línea de orilla, como de percepción visual y paisajística. El empleo de estructuras, tanto de gravedad (GBS), como pilotadas, trípodes, flotantes o de tecnología offshore, queda condicionada por los datos de partida descritos anteriormente. Además, podría añadirse que el cálculo de las fuerzas hidrodinámicas en las estructuras offshore, es uno de los problemas clave, para los ingenieros de diseño de hoy en día, que participan en la ingeniería marítima, como sugiere Negro et al. (2014)
Influence of temperature and salinity on hydrodynamic forces
Sobre el diagrama de fuerzas de inercia y de arrastre en un pilote empleado en energía eólica marina se analiza el efecto de la temperatura y la salinidad y, por ello, la relevancia en la turbulencia, Reynolds, CD y CM respectivamente.
The
purpose
of
this
study
is
to
introduce
an
innovative
approach
to
offshore
engineering
so
as
to
take
variations
in
sea
temperature
and
salinity
into
account
in
the
calculation
of
hydrodynamic
forces.
With
this
in
mind,
a
thorough
critical
analysis
of
the
influence
of
sea
temperature
and
salinity
on
hydrodynamic
forces
on
piles
like
those
used
nowadays
in
offshore
wind
farms
will
be
carried
out.
This
influence
on
hydrodynamic
forces
occurs
through
a
change
in
water
density
and
viscosity
due
to
temperature
and
salinity
variation.
Therefore,
the
aim
here
is
to
observe
whether
models
currently
used
to
estimate
wave
forces
on
piles
are
valid
for
different
ranges
of
sea
temperature
and
salinity
apart
from
observing
the
limit
when
diffraction
or
nonlinear
effects
arise
combining
both
effects
with
the
magnitude
of
the
pile
diameter.
Hence,
specific
software
has
been
developed
to
simulate
equations
in
fluid
mechanics
taking
into
account
nonlinear
and
diffraction
effects.
This
software
enables
wave
produced
forces
on
a
cylinder
supported
on
the
sea
bed
to
be
calculated.
The
study
includes
observations
on
the
calculation
model’s
sensitivity
as
to
a
variation
in
the
cylinder’s
diameter,
on
the
one
hand
and,
on
the
other,
as
to
temperature
and
salinity
variation.
This
software
will
enable
an
iterative
calculation
to
be
made
for
finding
out
the
shape
the
pressure
wave
caused
when
a
wave
passes
over
will
have
for
different
pile
diameters
and
water
with
different
temperature
and
salinity
El valor público de la acreditación en el mejoramiento continuo de las Carreras de Educación en Costa Rica. Un estudio de caso : a case study
The different accreditation processes of undergraduate degrees are the object of research due to the value of international recognition based on their accreditation. Thus, accreditation has become the preferred means of monitoring and evaluating the quality of higher education and observing universities' impact on society. The present study is part of a broader research focused on developing a doctoral thesis. It is framed in the qualitative interpretative paradigm of an emergent exploratory type. The main objective is to identify the public value generated by accreditation in the continuous improvement of undergraduate programs accredited by SINAES (an anagram of Sistema Nacional de Acreditación de la Educación Superior, National System of Higher Education Acceditation), in the field of education in Costa Rica. Five in-depth interviews were conducted to learn the perceptions of the key informants who participated in the accreditation process of the six selected degree programs. The results show the public value that accreditation produces in the continuous improvement of Education Degree Programs through ten categories that cover the achievements, benefits, results and effects of the contribution of SINAES in the continuous improvement processes of higher education. In conclusion, accreditation has become one of the determining factors when selecting an Education Degree Program in Costa Rica. The processes carried out by SINAES are perceived as legitimate and of excellence in developing these types of quality certifications.
Los diferentes procesos de acreditación por los que pasan los Grados universitarios son objeto de investigación debido al reconocimiento internacional que han adquirido por el valor asociado a la acreditación. De esta manera, la acreditación se ha convertido en el medio predilecto para supervisar y evaluar la calidad de la educación superior y observar el impacto que tienen las universidades en la sociedad. El estudio que se muestra forma parte de una investigación más amplia focalizada en el desarrollo de una tesis doctoral. Se enmarca en el paradigma cualitativo interpretativo de tipo exploratorio emergente. El objetivo principal se centra en identificar el valor público que genera la acreditación en el mejoramiento continuo de las carreras de grado acreditadas por el SINAES (Sistema Nacional de Acreditación de la Educación Superior) en el área de Educación en Costa Rica. Se ha llevaron a cabo cinco entrevistas a profundidad para conocer las percepciones de los informantes clave que participaron en el proceso de acreditación de las seis carreras seleccionadas. Los resultados muestran el valor público que produce la acreditación en el mejoramiento continuo de las Carreras de Educación por medio de 10 categorías que abarcan los logros, beneficios, resultados y efectos de la contribución del SINAES en el proceso de mejora continua de la Educación Superior. En conclusión, se observa como la acreditación se han convertido en uno de los factores determinantes a la hora de seleccionar una Carrera de Educación en Costa Rica. Los procesos llevados a cabo por el SINAES se perciben como legítimos y de excelencia en el desarrollo de este tipo de certificaciones de calidad
- …