2,830 research outputs found
Importancia de la detección y atención temprana de las dificultades en la lectura dentro de los problemas de aprendizaje, en el I ciclo de la Educación General Básica de las escuelas técnicas del circuito 03 de la Región Educativa de Cartago.
Trabajo final de graduación compuesto de 144 páginas en formato PDF.El alto grado de deserción y fracaso escolar en la educación primaria es un tema de importancia social.
Según la fundación ADA (Amigos del Aprendizaje, C.R), de cada 10 niños costarricenses que ingresan a la educación primaria, únicamente tres se gradúan de la educación secundaria.
Este fenómeno según la investigación de esta agrupación, es debido a que las dificultades en el aprendizaje inician desde primer grado y son factores claves para predecir la futura repitencia y deserción escolar de los niños y estas dificultades no son atendidas en forma temprana. Al no proveer atención adicional a los niños con dificultades en la lectura, estos están en alto riesgo de permanecer rezagados y eventualmente desertar del sistema escolar.Universidad Estatal a Distancia de Costa Ric
On the inversion of Stokes profiles with local stray-light contamination
Obtaining the magnetic properties of non-resolved structures in the solar
photosphere is always challenging and problems arise because the inversion is
carried out through the numerical minimization of a merit function that depends
on the proposed model. We investigate the reliability of inversions in which
the stray-light contamination is obtained from the same observations as a local
average. In this case, we show that it is fundamental to include the covariance
between the observed Stokes profiles and the stray-light contamination. The
ensuing modified merit function of the inversion process penalizes large
stray-light contaminations simply because of the presence of positive
correlations between the observables and the stray-light, fundamentally
produced by spatially variable systematics. We caution that using the wrong
merit function, artificially large stray-light contaminations might be
inferred. Since this effect disappears if the stray-light contamination is
obtained as an average over the full field-of-view, we recommend to take into
account stray-light contamination using a global approach.Comment: 5 pages, 3 figures, accepted for publication in Ap
Minimal repair of failed components in coherent systems
© 2019
This document is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the accepted version of a published work that appeared in final form in European Journal of Operational ResearchThe minimal repair replacement is a reasonable assumption in many practical systems. Under this as- sumption a failed component is replaced by another one whose reliability is the same as that of the component just before the failure, i.e., a used component with the same age. In this paper we study the minimal repair in coherent systems. We consider both the cases of independent and dependent compo- nents. Three replacement policies are studied. In the first one, the first failed component in the system is minimally repaired while, in the second one, we repair the component which causes the system fail- ure. A new technique based on the relevation transform is used to compute the reliability of the systems obtained under these replacement policies. In the third case, we consider the replacement policy which assigns the minimal repair to a fixed component in the system. We compare these three options un- der different stochastic criteria and for different system structures. In particular, we provide the optimal strategies for all the coherent systems with 1–4 independent and identically distributed components
La Universidad Accesible, la Universidad de Todos: políticas de adaptación y mejoras docentes para la inclusión de las personas con discapacidad
Se expone qué se define como Universidad Accesible y la importancia que adquiere disponer de una Universidad Accesible para garantizar la inclusión de las personas con discapacidad. Para ello se analizan las condiciones que precisa la accesibilidad en la universidad, los parámetros que debe cumplir y los aspectos que se deben considerar para su aplicación en los campus, tecnologías y servicios universitarios. Se pretende reflexionar sobre la situación actual en lo que se refiere al cumplimiento de los requisitos de Accesibilidad y Diseño para Todos, así como las necesidades de adaptación que requiere, tratando los aspectos propios de la docencia y la investigación, los arquitectónicos y los que afectan a las tecnología de la información. Por último se reflexiona sobre la situación actual y se identifican retos de futuro que permitirán garantizar una universidad accesible
Asymmetries of the Stokes V profiles observed by HINODE SOT/SP in the quiet Sun
We present the first classification of SOT/SP circular polarization
measurements with the aim of highlighting exhaustively the whole variety of
Stokes V shapes emerging from the quiet Sun. k-means is used to classify HINODE
SOT/SP Stokes V profiles observed in the quiet Sun network and internetwork
(IN). We analyze a 302 x 162 square arcsec field-of-view (FOV) which can be
considered a complete sample of quiet Sun measurements performed at at the disk
center with 0.32 arcsec angular resolution and 0.001 polarimetric sensitivity.
Such a classification allows us to divide the whole dataset in classes, with
each class represented by a cluster profile, i.e., the average of the profiles
in the class. The set of 35 cluster profiles derived from the analysis
completely characterizes SOT/SP quiet Sun measurements. The separation between
network and IN profile shapes is evident - classes in the network are not
present in the IN, and vice versa. Asymmetric profiles are approximatively 93 %
of the total number of profiles. Among these, approximatively 34 % of the
profiles are strongly asymmetric profiles, and they can be divided in three
families: blue-lobe, red-lobe, and Q-like profiles. The blue-lobe profiles tend
to be associated with upflows (granules), whereas the red-lobe and Q-like ones
appear in downflows (intergranular lanes). Such profiles need to be interpreted
considering model atmospheres different from a uniformly magnetized
Milne-Eddington (ME) atmosphere, i.e., characterized by gradients and/or
discontinuities in the magnetic field and velocity along the line-of-sight
(LOS).Comment: 11 pages, 4 figures, accepted for publication in Astronomy and
Astrophysic
Evolución histórica de la morfología urbana en los altiplanos nororientales de la provincia de Granada
Para conocer la esencia y la identidad de los diferentes asentamientos urbanos, los patrones
morfológicos son tan importantes como los económicos, sociales, políticos y culturales. Por
ese motivo, a continuación se va a analizar la evolución histórica de los asentamientos de las
comarcas de Baza y Huéscar, desde sus orígenes, sus sucesivas transformaciones, e identificando
y diseccionando sus variados componentes. El particular devenir histórico, los condicionantes
del medio natural, y las determinadas formas de vida, en esta zona, han quedado plasmadas en
la morfología urbana de sus pueblos y ciudades. Es decir, el solapamiento en asentamientos de
diversas culturas y usos etnográficos ha generado diversas morfologías y paisajes construidos,
de gran valor identitario, ambiental e histórico. Pero la globalización ignora la cultura local, el
paisaje urbano, transformando en confuso a este último, por lo que es preciso una valoración
social y un planeamiento urbano adecuado para su preservación en el tiempo.To know the essence and the identity of the different urban settlements, morphological
patterns are so important as the financial ones, social, politicians and cultural. For that reason,
we have to analyze the historical evolution of the regions’ settlements of Baza and Huéscar, from
its origin, successive transformations, and identifying and dissecting its varied ingredients. The
particular history, natural factors, and determined forms of life, in this zone, have been reflected
in the urban morphology of his villages and cities. That is, the overlap in settlements of several
cultures and ethnographical uses has generated several morphologies and built landscapes,
of great value environmental and historic. But the globalization ignores the local culture, the
cityscape, transforming in confusing to this last one, which is why is precise a social assessment
and a urban planification suitable for its preservation
Acoustical rehabilitation project of the Santa María de la Mota church, in Montoro (Córdoba)
The current importance of cultural heritage is traduced in recuperation programs of historic
heritage. One of these working lines is the rehabilitation of churches for their conditioning for
cultural uses. Intervention on ecclesiastic spaces should respond to acoustic conditioning.
The aim of this work is to study the acoustic conditions of the Santa María de la Mota Church, in
Montoro (Cordoba), starting from values measured in situ and by means of computer simulation.
This church, from the XIIIth century, was restored and adapted for cultural uses, but presents
acoustic disfunctions. Therefore, architectural solutions to obtain a correct acoustical
rehabilitation have been proposed, both for theatral and musical uses. Ponencia presentada en European and Japanese Symposium on Acoustics: Forum Acusticu
Statistical analysis of the very quiet Sun magnetism
The behavior of the observed polarization amplitudes with spatial resolution
is a strong constraint on the nature and organization of solar magnetic fields
below the resolution limit. We study the polarization of the very quiet Sun at
different spatial resolutions using ground- and space-based observations. It is
shown that 80% of the observed polarization signals do not change with spatial
resolution, suggesting that, observationally, the very quiet Sun magnetism
remains the same despite the high spatial resolution of space-based
observations. Our analysis also reveals a cascade of spatial scales for the
magnetic field within the resolution element. It is manifest that the Zeeman
effect is sensitive to the microturbulent field usually associated to Hanle
diagnostics. This demonstrates that Zeeman and Hanle studies show complementary
perspectives of the same magnetism.Comment: Accepted for publication in Ap
Minimal repair of failed components in coherent systems
The minimal repair replacement is a reasonable assumption in many practical systems. Under this
assumption a failed component is replaced by another one whose reliability is the same as that of
the component just before the failure, i.e., a used component with the same age. In this paper
we study the minimal repair in coherent systems. We consider both the cases of independent and
dependent components. Three replacement policies are studied. In the first one, the first failed
component in the system is minimally repaired while, in the second one, we repair the component
which causes the system failure. A new technique based on the relevation transform is used to
compute the reliability of the systems obtained under these replacement policies. In the third
case, we consider the replacement policy which assigns the minimal repair to a fixed component
in the system. We compare these three options under different stochastic criteria and for different
system structures. In particular, we provide the optimal strategy for all the coherent systems with
1-4 independent and identically distributed components
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