680 research outputs found
Hexagonal Tilings: Tutte Uniqueness
We develop the necessary machinery in order to prove that hexagonal tilings
are uniquely determined by their Tutte polynomial, showing as an example how to
apply this technique to the toroidal hexagonal tiling.Comment: 12 figure
Hexagonal Tilings and Locally C6 Graphs
We give a complete classification of hexagonal tilings and locally C6 graphs,
by showing that each of them has a natural embedding in the torus or in the
Klein bottle. We also show that locally grid graphs are minors of hexagonal
tilings (and by duality of locally C6 graphs) by contraction of a perfect
matching and deletion of the resulting parallel edges, in a form suitable for
the study of their Tutte uniqueness.Comment: 14 figure
Jóvenes y políticas territoriales de educación y empleo. El impacto del proyecto social de Escuelas Taller de Oficios del municipio La Habana Vieja en las condiciones de vida de un grupo de jóvenes.
El presente informe muestra los resultados de una investigación que tuvo como objetivo general analizar el impacto del proyecto social de escuelas de oficio del municipio La Habana Vieja en las condiciones de vida de un grupo de jóvenes, a partir de la incorporación de los mismos a un proceso de formación y capacitación para el empleo. Entre los principales resultados del estudio, figura un recorrido teórico sobre la relación entre jóvenes, políticas territoriales de empleo y desarrollo local; un análisis de la políticas sociales para la inserción laboral de los jóvenes en Cuba; y la explicitación de los cambios en las condiciones de vida, desde una perspectiva de género. Concluye con reflexiones que dan cuenta de la efectividad de la política territorial de desarrollo local para generar un cambio en las realidades de un grupo de jóvenes que no estudiaban ni trabajaban, antes de insertarse en el proyecto
Relationships between adolescent physical self-concept and physical activity
El objetivo de este estudio es someter a prueba dos modelos
contrapuestos sobre las relaciones entre las autopercepciones físicas y la
actividad físico-deportiva en la adolescencia: mientras que un modelo postula la
influencia de la actividad física sobre el autoconcepto físico, el modelo alternativo
propone al autoconcepto físico como factor influyente en la actividad físicodeportiva.
Participan en la investigación 704 estudiantes, 394 (55.96 %) hombres
y 310 (44.04 %) mujeres entre 11 y 19 años (M = 14.91; D.T. = 2.13), residentes
en dos Comunidades Autónomas (Cantabria y País Vasco) de España. Los
resultados indican que las influencias entre el autoconcepto físico y la actividad
físico-deportiva se producen de forma bidireccional si bien ajusta mejor el modelo
que propone al autoconcepto físico como factor influyente. Se comprueban
diferencias entre hombres y mujeres en el modelo. Por otro lado, la
autopercepción de atractivo físico mantiene una relación negativa con la
actividad físico-deportivaThe aim of this study is to test two opposing models of the relationship between
physical self-perceptions and physical activity during adolescence: one which
postulates that physical activity influences physical self-concept, and another
one which proposes that physical self-concept influences physical activity.
Participants were 704 students aged between 11 and 19 (M = 14.91; SD = 2.13)
from two different Autonomous Regions in Spain (Cantabria and the Basque
Country). 394 (55.96%) were male and 310 (44.04%) were female. The results
indicate that the influences between physical self-concept and physical activity
are bidirectional in nature, although the model that proposes physical selfconcept
as an influencing factor was found to have a better fitness. Differences
were found in the model between male and female students. Furthermore, selfperception
of physical attractiveness was found to be negatively related to
physical activityEste artículo lo firman componentes del Grupo Consolidado de Investigación del Sistema
Universitario Vasco IT701-13 y forman parte de los resultados del proyecto EDU2009-10102
(subprograma EDUC) subvencionado por el MICINN. La investigación se ha realizado con la
colaboración del Programa para la Contratación de Doctores Recientes de la Universidad del
País Vasco (UPV/EHU
The quasi-cylindrical description of submerged laminar swirling jets
TThe quasi-cylindrical approximation is used to describe numerically the structure of a submerged swirling jet for subcritical values of the swirl ratio S<Sc . The emerging flow structure is affected by the swirling motion, which enhances the entrainment rate of the jet and induces an adverse pressure gradient that reduces its momentum flux. The effect is more pronounced as the swirl ratio S is increased, yielding for sufficiently large values of S a jet with an annular structure. The integration describes the smooth transition towards the far-field self-similar solution for all values of S smaller than a critical value S5Sc , at which the numerical integration fails to converge at a given downstream location. The comparisons with previous experimental results confirm the correspondence between the onset of vortex breakdown and the failure of the quasi-cylindrical approximation
Laboratorio remoto en un entorno virtual de enseñanza aprendizaje
El objetivo principal de esta tesis es desarrollar una propuesta didáctica de Laboratorio Remoto (LR) en un Entorno Virtual de Enseñanza y Aprendizaje (EVEA) que favorezca el aprendizaje de programación basada en lenguaje de alto nivel
Para posibilitar esta investigación se requirió la adecuación de la plataforma educativa que en particular se implementó en base a Moodle, para dotar a la misma de los recursos didácticos necesarios.
Con el fin de evaluar las actividades, se implementó una rúbrica que permite valorar los desempeños de los alumnos mediante la observación de indicadores de logro que facilitan el reconocimiento de los mismos y permiten caracterizar el grado en que se cumplen los desempeños. Esta herramienta de evaluación se sometió al proceso de validación de contenido mediante el método del juicio de expertos.
Se presenta el trabajo experimental, mostrándose los resultados obtenidos y la opinión de los alumnos expresada mediante un cuestionario de satisfacción elaborado al efecto.Facultad de Informátic
Metallo-organic ensembles of tritopic subphthalocyanine ligands
"This is the peer reviewed version of the following article: M. Ángel Revuelta-Maza, Ettore Fazio, Gema de la Torre and Tomás Torres, Metallo-organic ensembles of tritopic subphthalocyanine ligands, Journal of Porphyrins and PhthalocyaninesVol. 21, No. 12, pp. 782-789 (2017), which has been published in final form at https://doi.org/10.1142/S1088424617500882I. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use Self-Archived Versions"Organic building blocks containing amines and aldehydes can be used for the preparation of complex metallo-organic structures, such as M2L3 triple helicates or face-capped M4L4 tetrahedral cages, through the formation of both dynamic covalent and coordinative linkages during the self-Assembly process. Herein we describe how the subcomponent self-Assembly method can be succesfully applied over a triamine-functionalized subphthalocyanine (SubPc) ligand to build metallo-supramolecular helicates. Two isomeric SubPcs (C1-SubPc1 and C3-SubPc1) have been prepared from the corresponding C1-SubPcI3 and C3-SubPcI3 precursors under optimized Suzuki conditions. We selected the tritopic C3-SubPc1 derivative as ligand for the subcomponent self-Assembly experiments, which involved the reaction with 2-formylpyridine and different Fe(II) salts. The self-Assembly process was mainly studied by mass spectrometry (ESI direct injection techniques), and in all the conditions applied, we could observe the formation of helicate-Type Fe2SubPc3 structures and/or Fe2SubPc4 species, which can be considered as open precursors of Fe4SubPc4 tetrahedral cages. © 2017 World Scientific Publishing Company.Financial support from Comunidad de Madrid, Spain (S2013/MIT- 2841, FOTOCARBON), and Spanish MICINN (CTQ2014-52869-P) is acknowledged
Diseño e implantación de un sistema de mentoreo desde el marco del desarrollo humano en una organización con fines de lucro
En este trabajo se describe el diseño y la implementación de un sistema de mentoreo congruente con el Enfoque Centrado en la Persona (ECP) aplicado a la educación en un grupo de empresas agrupadas bajo el nombre de “EG” que, entre todas, cuentan aproximadamente con 800 colaboradores. Se facilitó la creación de una universidad corporativa que articula, en forma institucional, el sistema de formación que da respuesta a las necesidades de formación, adiestramiento, capacitación e instrucción de los colaboradores de la empresa y, dentro de dicho sistema, se ideo e instaló un sistema de mentoreo construido sobre la base de los principios de la psicología humanista, el ECP, el enfoque constructivista en educación, la educación a distancia, el diseño instruccional y el modelo conocido como “la quinta disciplina”. Un hallazgo relevante que se establece al finalizar el trabajo, es la confirmación de que se puede implantar un sistema de mentoreo con ECP en organizaciones que tienen una clara finalidad de lucro con el propósito de impulsar el desarrollo humano de los trabajadores
EDROOM: a free tool for the UML2 component based design and automatic code generation of tiny embedded real time system
International audienceThe use of tiny real time kernels to develop embedded systems is broadly extended. They offer basic services with small overhead footprints in the final product. Usually, these kind of kernels are compliant with the POSIX 1003.13 specification. The use of graphical modelling and automatic code generation tools for developing these kind of small software embedded system if often not considered for several reasons: they are expensive, the learning curve to obtain benefits is often large and finally the generated code usually does not fit well with the platform or exceed the desired size. In this paper we present the adaptation of a free tool, known as EDROOM, to develop this kind of real time software system. EDROOM is inspired on the ROOM modelling language and provides graphical modelling and automatic Embedded C++ code generation. EDROOM is compliant with the new UML2 graphical notation for component based system design and hierarchical behaviour. The new version of EDROOM is a cross development multiplatform generation tool and includes facilities for static control of all resources in order to completely avoid the use of dynamic memory. Our tool has been used in the software development of a small satellite (NANOSAT-01) which is fully functional nowadays. The tool is free distributed in conjunction with a group of code test bench that can be used to validate any port to another architecture
Laminar Craya-Curtet jets
This Brief Communication investigates laminar Craya-Curtet flows, formed when a jet with moderately large Reynolds number discharges into a coaxial ducted flow of much larger radius. It is seen that the Craya-Curtet number, C=(J/sub c//J/sub j/)/sup 1/2/, defined as the square root of the ratio of the momentum flux of the coflowing stream to that of the central jet, arises as the single governing parameter when the boundary-layer approximation is used to describe the resulting steady slender jet. The numerical integrations show that for C above a critical value C/sub c/ the resulting streamlines remain aligned with the axis, while for C<C/sub c/ the entrainment demands of the jet cannot be satisfied by the coflow, and a toroidal recirculation region forms. The critical Craya-Curtet number is determined for both uniform and parabolic coflow, yielding C/sub c/=0.65 and C/sub c/=0.77, respectively. The streamlines determined numerically are compared with those obtained experimentally by flow visualizations, yielding good agreement in the resulting flow structure and also in the value of C/sub c
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