5,407 research outputs found
Orientaciones de lenguaje de estudiantes de secundaria chilenos en relación al estudio de inglés como lengua extranjera
Why teach English in Chile? Dominant public discourse claims for economic development, but with limited social mobility, do students from differing socio-economic groups perceive the same need? Recognising the influence of student belief systems on language acquisition, clashing language orientations could be creating unfavourable classroom environments. Thus, this study set out to identify the language orientations that secondary students recognise and hold in relation to the study of English with the purpose of helping English as foreign language (EFL) teachers become aware of the plurality of student perceptions. This was a qualitative multiple-case study which utilised a card-sorting technique paired with hierarchical cluster analysis and multidimensional scaling (MDS) to identify the language orientations and their constructs and semi-structured interviews and classroom observations for verification. Whilst the language orientations students recognise and hold were found to be similar across socio-economic lines, an important issue is the divergence identified between the language orientations associated with the classroom and those that represent student interests, which could be explained due to the lack of intentional and conscious dialogue about the purpose of the classroom curriculum. Vision planning is proposed as a tool for teachers to address this breach between students and classroom curriculum.¿Por qué enseñar inglés en Chile? El discurso público dominante reclama desarrollo económico, pero con movilidad social limitada. ¿Perciben los diferentes grupos socioeconómicos la misma necesidad? Reconociendo la influencia de los sistemas de creencias estudiantiles en la adquisición de lenguaje, las orientaciones de lenguaje contradictorias podrían crear entornos de aula desfavorables. Por ello, este estudio se propuso identificar las orientaciones de lenguaje que los estudiantes de secundaria reconocen y mantienen en relación con el estudio del inglés con el propósito de ayudar a los docentes de inglés como lengua extranjera (EFL) a tomar conciencia de la pluralidad de percepciones estudiantiles. Este estudio cualitativo de caso múltiple utilizó el ordenamiento de tarjetas con análisis jerárquico y escalamiento multidimensional para identificar las orientaciones y sus construcciones, y entrevistas semiestructuradas y observaciones en aula para verificación. Mientras se encontró que las orientaciones que los estudiantes reconocen y mantienen son similares en todos los niveles socioeconómicos, un problema importante es la divergencia entre las orientaciones asociadas con el aula y las que representan el interés estudiantil, lo que podría explicarse debido a la falta de diálogo intencional sobre el propósito del currículo. Se propone la planificación de visión como una herramienta para que los docentes aborden esta brecha entre los estudiantes y el currículo
Codimension two and three Kneser Transversals
Let be integers with and let
be a finite set of points in . A -plane
transversal to the convex hulls of all -sets of is called Kneser
transversal. If in addition contains points of , then
is called complete Kneser transversal.In this paper, we present various
results on the existence of (complete) Kneser transversals for .
In order to do this, we introduce the notions of stability and instability for
(complete) Kneser transversals. We first give a stability result for
collections of points in with
and . We then present a description of
Kneser transversals of collections of points in
with for . We show that
either is a complete Kneser transversal or it contains
points and the remaining points of are matched in pairs in
such a way that intersects the corresponding closed segments determined by
them. The latter leads to new upper and lower bounds (in the case when and ) for defined as the maximum positive integer
such that every set of points (not necessarily in general position) in
admit a Kneser transversal.Finally, by using oriented matroid
machinery, we present some computational results (closely related to the
stability and unstability notions). We determine the existence of (complete)
Kneser transversals for each of the different order types of
configurations of points in
JPEG Compressed Images Can Bypass Protections Against AI Editing
Recently developed text-to-image diffusion models make it easy to edit or
create high-quality images. Their ease of use has raised concerns about the
potential for malicious editing or deepfake creation. Imperceptible
perturbations have been proposed as a means of protecting images from malicious
editing by preventing diffusion models from generating realistic images.
However, we find that the aforementioned perturbations are not robust to JPEG
compression, which poses a major weakness because of the common usage and
availability of JPEG. We discuss the importance of robustness for additive
imperceptible perturbations and encourage alternative approaches to protect
images against editing.Comment: 8 pages, 8 figure
The educational success in a small province of Ecuador
Exitus: Factores de éxito escolar en la Provincia de Carchi, Ecuador”, Universidad Nacional de
Educación (UNAE), Ecuador. El equipo de investigación está integrado por los PhD: Marielsa
López (IP), Silverio González, Marco Vinicio Vázquez, Ana Rosa Di Gravia y Stafos Efstathios.
Y los bachilleres Kellly Loaiza, Michelle Arias y Pedro SandovalEn la Provincia de Carchi, Ecuador, se encuentran las escuelas primarias con los
mejores docentes y los resultados académicos del país (INEVAL, 2015). En contra
de lo que podría esperarse es una provincia agrícola, pobre y fronteriza. El objetivo
de la investigación es estudiar los factores que explican estos resultados. La
metodología que se utilizó fue cualitativa. Los resultados indican que los docentes
son la clave del éxito de la provincia: dominan el contenido de la materia que
dictan, utilizan una metodología de “preguntas/respuestas”, enfocados en un solo
tema, con actividades de dificultad progresiva y que llevan a los alumnos de lo
concreto a lo simbólico y a lo abstracto. Utilizan cierres parciales para ayudar a los
alumnos a fijar el conocimiento. Mantienen relaciones afectivas con los alumnos y
utilizan refuerzos positivos focalizados. Usan la repetición como medio para fijar
los aprendizajes. Los alumnos son respetuosos y ordenados. El clima de las escuelas
es altamente positivoIn the Province of Carchi, Ecuador, there are primary schools with the best
teachers performances and the best students learning achievement of the country
(INEVAL, 2015). Contrary to what one might expect is an agricultural province,
poor and frontier. The objective of the research is to study the factors that explain
these results. The methodology used was qualitative. The results indicate that
teachers are the key to the success of the province: they master the content of the
subject they teach, they use a methodology of "questions / answers", focused on a
single subject, with activities of progressive difficulty and that lead from the
concrete to the symbolic and the abstract thought. They use partial closures of the
lessons to help students set the knowledge. They maintain affective relationships
with students and use focused positive reinforcements. They use repetition as a
means to fix learning. Students are respectful and orderly. The climate of schools is
highly positiv
Theoretical and practical validation tests for a near-field to far-field transformation algorithm using spherical wave expansion
The use of spherical wave expansion of the solution of the wave equation to predict Far-Field values from data measured in the Near-Field region is a well known technique, typically used to perform antenna measurements in compact anechoic chambers. However, when designing the computing algorithm it is fundamental to validate the results and to quantify the numerical error of the method. In this regard, a computer application that samples the electric Near-Field and calculates the values of the electric Far-Field region using spherical wave expansion was developed to measure antenna radiation patterns in
the Fresnel zone inside a fully anechoic chamber. In order to validate the code, this paper describes three validation methods: firstly, using the theoretical electric Near-Field values of an infinitesimal dipole as the input to the algorithm to compare the output with the response analytically expected; secondly, using a Far-Field electric field data of a calibrated half wavelength dipole measured in an anechoic chamber and finally, using an electric Near-Field data of a calibrated half wavelength dipole measured in the same chamber. These methods provide simple procedures to calculate the error introduced by the code in different scenarios that should be considered to estimate the measurement uncertainty.Postprint (published version
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