230 research outputs found
Construcció i aprofitament didàctic del coet d'aigua
El present treball constitueix una proposta de construcció i llançament d'un coet d'aigua i l'estudi experimental del tir parabòlic del mateix. El treball està dirigit a l'alumnat de 1r Batxillerat o 4t d'Educació Secundària de Física i Química i aporta material didàctic perquè el professorat pugui aprofitar aquest atractiu dispositiu.This paper is a proposal to build, launch and experimental study of oblique shot of a water rocket. The work is aimed at students of Secondary Education in Physics and Chemistry and provides educational materials for teachers to take advantage of this attractive device
Constructing tasks for primary teacher education from the perspective of Mathematics Teachers’ Specialised Knowledge
International audienceDeveloping tasks to help prospective teachers construct professional knowledge is an under-researched area of teacher education. In this paper we focus on describing the process of generating tasks in a research project at the University of Huelva. Using the model Mathematics Teachers’ Specialized Knowledge we designed tasks to prompt the construction of specific elements of knowledge necessary for teaching mathematics, with the involvement of educators and prospective teachers selected ad hoc. As an example, we describe elements from a task focused on the notion of a polygon
Mathematics teacher’s specialized knowledge (mtsk) in the “dissecting an equilateral triangle” problem
This paper focuses on describing a model for the analysis of the mathematics teachers’ knowledge from the perspective of what is peculiar to teaching mathematics, and gives an example of its application to the knowledge deployed by a teacher during a lesson. We first present the analytical model, the MTSK (mathematics teacher’s specialized knowledge) model, developed at the University of Huelva (Spain), and then demonstrate its potential in the case of a high school teacher working through a problem with her students. We conclude with a summary of the advantages the model offers in detailing the elements of specialized knowledge displayed by the teacher, and illustrate how this knowledge enables her to plan highly productive learning opportunities for her students. A final reflection notes the potential of the MTSK model as a tool for teacher training
Cognitive processes associated with the professional development of mathematics teacher
This paper proposes a model of professional development based on Sfard’s stages of interiorisation, condensation and reification, which highlights the teacher’s cognitive processes. The model is applied to the case study of a primary teacher participating in a collaborative project for professional development. This adaptation of Sfard’s stages proves to be of special value when interpreting the process of the teacher’s professional development from a cognitive perspective
Cognitive processes associated with the professional development of the mathematics teacher
This paper proposes a model of professional development based on Sfard’s stages of interiorisation, condensation and reification, which highlights the teacher’s cognitive processes. The model is applied to the case study of a primary teacher participating in a collaborative project for professional development. This adaptation of Sfard’s stages proves to be of special value when interpreting the process of the teacher’s professional development from a cognitive perspective. Procesos cognitivos asociados al desarrollo profesional del profesor de matemáticas Este artículo propone un modelo de desarrollo profesional que pone de relieve los procesos cognitivos del profesor, en relación con las fases de interiorización, condensación y cosificación del trabajo de Sfard. El modelo se aplica al caso de una maestra que participa en un proyecto colaborativo de desarrollo profesional. La adaptación de las fases de Sfard se muestra valiosa para interpretar el proceso de desarrollo profesional de la maestra desde una perspectiva cognitiva. Handle: http://hdl.handle.net/10481/3509Nº de citas en WOS (2017): 1 (Citas de 2º orden, 0)Nº de citas en SCOPUS (2017); 1 (Citas de 2º orden, 1
Un modelo cognitivo para interpretar el desarrollo profesional de los profesores de matemáticas. Ejemplificación en un entorno colaborativo
A partir del trabajo de Sfard en relación con las fases de interiorización, condensación y cosificación para explicar los procesos cognitivos referidos al aprendizaje de las matemáticas, realizamos una propuesta de modelo interpretativo del desarrollo profesional. A continuación, analizamos sus características aplicándolo al caso de una maestra participante en un entorno colaborativo de desarrollo profesional, evidenciando de este modo las potencialidades del modelo.Based on Sfard's stages of interiorisation, condensation and reification, which she applies to explain the cognitive processes in relation to the mathematical learning, we propose an interpretative model of professional development. We analyse its features and then the model is applied to the case study of a primary teacher participating in a collaborative project for professional development. This way we show the model's potentialities
What knowledge and conceptions mobilize future teachers analyzing a classroom video?
El uso del vídeo de sesiones de clase de Educación Primaria
(EP) en la formación inicial del maestro aporta realismo a las
discusiones teóricas de las aulas de magisterio, contribuyendo
a la vinculación entre la teoría y la práctica sobre la base de
procesos reflexivos que ayudan a trascender los habituales
comentarios genéricos de los estudiantes para maestro (EPM).
El objetivo de este estudio es identificar las concepciones sobre
la enseñanza y el aprendizaje de las matemáticas así como el
conocimiento matemático para la enseñanza (particularmente
el conocimiento de matemáticas y la enseñanza y el conocimiento
de matemáticas y los estudiantes) que un grupo de EPM pone
en juego cuando observa un vídeo de EP. Mediante un diseño
de investigación consistente con un experimento de enseñanza
(Steffe y Thompson, 2000) (en el que un diseño instruccional,
orientado a los EPM, acerca de la introducción del concepto
de división, se va refinando a través de sucesivos ciclos de
implementación y análisis), se pone de relieve cómo el análisis
de situaciones de enseñanza en EP promueve el cuestionamiento de
los EPM.The use of the Primary Education (PE) class sessions video in
the initial training of teachers provides realism to the theoretical
discussions of Master’s degree classrooms, contributing to
the link between theory and practice on the basis of reflective
processes that help to transcend the normal general comments of
teacher students (TS). The objective of this study is to identify
the conceptions for the teaching and learning of mathematics, as
well as the mathematical knowledge for teaching (particularly
the knowledge of mathematics and the teaching and knowledge
of mathematics and students) that a group of TS use when observing a PE video. Using a research design consistent with a
teaching experiment (Steffe and Thompson, 2000) (in which an
instructional design, aimed at TS, regarding the introduction of
the concept of division, is refined by means of successive cycles
of implementation and analysis), the way the analysis of teaching
situations in PE promotes the questioning of TS is highlighted.O uso de vídeos de sessões de aula de Educação Primária
(EP) na formação inicial do professor oferece realismo às
discussões teóricas sobre as aulas de magistério, contribuindo
para a vinculação entre a teoria e a prática sobre a base
de processos reflexivos que ajudam a transcender os habituais
comentários genéricos dos estudantes para professores (EPM). O
objetivo deste estudo é identificar as concepções sobre o ensino e
a aprendizagem da matemática, assim como o conhecimento
matemático para o ensino (particularmente o conhecimento de
matemática e o ensino e o conhecimento de matemática e dos
estudantes) que um grupo de EPM põe em jogo quando
observa a um vídeo de EP. Através de uma criação de pesquisa
consistente com um experimento de ensino (Steffe e Thompson,
2000), destaca-se como a análise de situações de ensino em EP
promove o questionamento dos EPM.L’utilisation de la vidéo pour une classe d’élèves en école
primaire (EP) durant la formation des futurs instituteurs
confère un certain réalisme aux discussions théoriques qui
ont lieu dans les cours de formation des instituteurs
(l’équivalent en France des IUFM) en contribuant à la création
de liens entre théorie et pratique basés sur des processus
réflexifs qui permettent aux étudiants d’aller au-delà des
habituels commentaires généraux. L’objectif de la présente
étude consiste à identifier les conceptions sur l’enseignement et
l’apprentissage des mathématiques ainsi qu’à s’interroger sur la
connaissance mathématique pour l’enseignement (en particulier,
la connaissance des mathématiques et l’enseignement des
mathématiques et les étudiants) qu’un groupe de futurs
instituteurs utilise lorsqu’il observe une vidéo conçue pour
l’école primaire. Grâce à un travail de recherche qui va de pair
avec une expérience sur l’enseignement (Steffe et Thompson,
2000) (dans lequel un travail propre à l’enseignement conçu
pour les futurs instituteurs portant sur l’introduction du concept
de division s’affine de plus en plus au fur et à mesure que des
cycles successifs de mises en oeuvre et d’analyse sont utilisés),
on montre comment l’analyse de situations en école primaire
suscite le questionnement des futurs instituteurs
Caracterización de las propiedades de durabilidad y resistencia a compresión de lechadas de cemento con escoria de alto horno para trabajos geotécnicos especiales
Special foundations, most prominently micropiles and soil anchors, are frequently used in construction today. In Spain, the grout for these special technical applications is generally prepared with portland cement, although the codes and standards in place stipulate only the minimum compressive strength required, with no mention of cement type. Those texts also establish a range of acceptable water:cement ratios. In the present study, durability and compressive strength in cement grout prepared with blast furnace slag cement at different w/c ratios are characterised and compared to the findings for a reference portland cement grout. The results show that slag grout exhibits greater durability than the portland cement material and complies with the compressive strength requirements laid down in the respective codes.Actualmente es muy frecuente el empleo de cimentaciones especiales, entre las que destacan los micropilotes y los anclajes. En España, las lechadas de cemento para estos trabajos geotécnicos especiales se preparan habitualmente con cemento Portland, aunque las diferentes normativas al respecto no restringen el tipo de cemento a emplear, siempre que se alcance una determinada resistencia a compresión. Respecto a la dosificación de las lechadas, la normativa permite emplear diferentes relaciones agua/cemento dentro de un determinado rango. En vista de ello, en este trabajo se han caracterizado las propiedades de durabilidad y resistencia a compresión de lechadas de cemento preparadas con un cemento con escoria de alto horno y con diferentes relaciones a/c, tomando como referencia de comportamiento lechadas de cemento Portland. El uso de un cemento con escoria conlleva una mejora en la durabilidad de las lechadas, cumpliendo los requisitos de resistencia a compresión establecidos por la normativa.This research was funded by the Spanish Ministry of Economy and Competitiveness (formerly by the Spanish Ministry of Science and Innovation) and FEDER through projects BIA2010-20548 and BIA2011-25721
Volumetric efficiency modelling of internal combustion engines based on a novel adaptive learning algorithm of artificial neural networks
[EN] Air mass flow determination is one of the main variables on the control of internal combustion engines. Effectiveness of intake air systems is evaluated through the volumetric efficiency coefficient. Intake air systems characterization by means of physical models needs either significant amount of input data or notable calculation times. Because of these drawbacks, empirical approaches are often used by means of black-box models based on Artificial Neural Networks. As alternative to the standard gradient descendent method an adaptive learning algorithm is developed based on the increase of hidden layer weight update speed. The results presented in this paper show that the proposed adaptive learning method performs with higher learning speed, reduced computational resources and lower network complexities. A parametric study of several Multiple Layer Perceptron (MLP) networks is carried out with the variation of the number of epochs, number of hidden neurons, momentum coefficient and learning algorithm. The training and validation data are obtained from steady state tests carried out in an automotive turbocharged diesel engine. (C) 2017 Elsevier Ltd. All rights reserved.Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)", grant for doctoral studies (FPI S1 2015 2512), of Universitat Politecnica de Valencia.Luján, JM.; Climent, H.; García-Cuevas González, LM.; Moratal-Martínez, AA. (2017). Volumetric efficiency modelling of internal combustion engines based on a novel adaptive learning algorithm of artificial neural networks. Applied Thermal Engineering. 123:625-634. https://doi.org/10.1016/j.applthermaleng.2017.05.087S62563412
Genetic, environmental and ontogenetic effects on cone serotiny in Aleppo pine (Pinus halepensis Mill.): abstract
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